TEN is an electric heater of a liquid in the form of a metal tube, inside which there is a spiral. There are many designs, varieties. Heaters are manufactured in both large and small industries.
These heaters are massively installed, for example, in electric boilers and electric boilers, therefore they are also produced by well-known manufacturers.
But in any market you can find heating elements intended for installation in heating radiators. These devices are made more often in Poland, Ukraine, China. They can be supplied with built-in temperature sensors, i.e. work in semi-automatic mode, monitoring the degree of heating.
Based on such electric heaters, you can easily create a heating device with your own hands. This is what home craftsmen use, constructing the simplest heating and "saving" at the same time, as they think, a fair amount of money.
But is it so beneficial to use heating elements?
Where is it usually, in what situations, are these electric water heaters used? How to install and use heating elements ...
How big is the benefit from heating elements
If there is an old battery, then why not turn it into a heating system for a small utility room, - chicken coop, workshop, garage ...
There are even myths that it is profitable to heat with shades. But "dreams crash against harsh reality" - electricity is the most expensive thing to heat. Since the most expensive energy source is used.
It does not matter whether there is a proprietary programmable electric boiler, or a barrel is installed with a heating element lowered into it on a wire - the efficiency of such electric heaters is about 97%. And then we pay according to the counter ...
Keep warm at night
But there is a loophole - the nightly cheap electricity rate. You can find out exactly about the current tariffs and the possibility of connecting the night one in the local power grid.
True, and nighttime electricity cannot be called cheap, but in conjunction with the "Comfort" indicator, night heating becomes very attractive for the user.
But the price of the heating system itself with electric heating can vary considerably.
Battery heaters
When it is cold in apartments with central heating, they are additionally heated with electricity, as well as gas kitchen stove or column.
This is where a couple of heavy cast-iron batteries with heating elements are used. Compared to branded electric convectors, they have a much higher heat capacity, so they can be turned off for a longer time and not be monitored. But heating is correspondingly longer.
Craftsmen install such radiators mainly in garages, where they like to spend time. Or, for example, for heating animals in cold weather on small farms.
Heating systems equipment
It happens that at the dacha, in the garage, etc. there are remnants of the former heating system, for example, a pair of radiators with steel pipes. The easiest way to bring the system back to life is to insert electric heaters….
But heating elements can also create auxiliary heating in home system heating. Electric heating perfectly complements the solid fuel boiler. Especially at night, with a cheap rate. And here " homemade production»Is also in demand.
If large enough metal pipe fix a couple of tens of 2 kW each, you get a 4-kilowatt electric boiler. The nuance is that at night it can be connected to a low-power 220 V network, since other consumers "sleep", except for the refrigerator, for example.
Such a "creation", in practice, can become the main heating during the season in an insulated house, if, of course, it is used buffer tank- heat accumulator.
What power is needed
In the heating system of the whole house, it is better to use 2-kilowatt samples of electric heaters.
But in individual radiators of home-made registers, scraps of heating in garages ... it is impossible to use too powerful heating elements.
Consequently, the power of the heating element should not be more than the heat output given by the device at +70 degrees. This is approximately 75% of the radiator's rated power.
One section of both cast iron and aluminum radiators (500 mm between the pipes) has a heat transfer power of 170 W at 90 degrees of liquid and 20 degrees of air. At +70 deg. heating - one section - 140 W, 7 sections - 1080 W, 10 sections. - 1400 W.
Thus, for a radiator of 7 sections, the power of the heating element should not be more than 1 kW. And for a radiator of 10 sections - no more than 1.4 kW.
The situation with self-made registers is more difficult - their heat transfer is unknown. All that remains is to start using the least powerful heaters.
What shades for a radiator to choose
Heating elements for radiators are made on the basis of a plug (base) with a standard thread diameter of 40 mm. It remains to unscrew the bottom plug from the radiator, screw the heater in its place.
The selection of these heaters in terms of power for radiators was mentioned above. You should not take more powerful devices in order to avoid emergency situations. There is no need to overheat the radiator to achieve greater heat dissipation.
But these heaters also vary in length. For a free-standing radiator, without fluid movement, longer shades are preferable. Then the heating will be more even.
In a flow-through electric boiler, another selection priority is a lower hydraulic resistance. It is not a problem for the home craftsman to minimize the influence of the heaters by the successful supply of pipes and their configuration.
The manufacturer, - the "Chinese", as before, are scolded most of all, the best heating elements are local spills - Russian-Ukrainian.
How to apply
Heating elements can be switched on by a room thermostat. Then they are controlled according to the set air temperature.
But in most cases, heaters with built-in temperature relays are used - heating according to the temperature of the coolant.
The liquid expands when heated. Separate radiators and other closed heating systems cannot be completely filled with liquid. In heating systems, an expansion vessel is used to compensate for expansion.
In the case of a separate radiator, it is enough to leave at least 10% of the internal volume not filled, - pour the radiator over the top plug.
The installation of the heating element is as follows. The system is drained, the radiator cap is unscrewed, the ten is screwed in. In this case, flax with a lubricant is usually used as a seal (metal-to-metal).
The heater is connected to the mains in accordance with the PUE, with appropriate insulation of the contacts.
Oil not acceptable
You can find recommendations to fill the radiator with oil - supposedly you get an analogue of an "oil heater". Before following such advice, it is recommended to study the experience of a "pyrotechnician" who poured oil on cardboard, set it on fire, and then tried to extinguish it.
Oil-filled industrial electrical units (for example, high-voltage oil disconnectors) are operated with special fire safety measures.
If the system freezes, it is necessary to use anti-freezing liquids; for one radiator, you can use the same automotive Antifreeze. Flammable liquids are not permitted.
There are other violations as well.
Is DIY design profitable?
Self-construction of electric heating devices is discouraged for safety reasons.
It is much more expedient to purchase a ready-made electric space heater, for example, an electric convector that meets the requirements ... The manufacturer is responsible for its performance.
Economic feasibility in heating elements can arise, as it was said, when there is an "abandoned" and "free" shell for it.
But security issues are actually much more important than the benefits obtained in this way.
Now this is understood more often, because heating elements are becoming less and less interested.
To make an instantaneous water heater with your own hands - great idea if you suffer from a lack of hot water in the summer or want to organize a shower in the country. You can make a flute pipe yourself, because it is quite simple in structure. What you need for work and what stages you have to go through, you will find out in the article.
We wrote in detail about how the boiler works in the article "".
Let's list the main nodes and consider the principle of operation. The body of the device is equipped with a flow heater, which is placed in a protective flask, therefore it is practically not subject to scale. Water flows through the heater reaching optimal temperature... The advantage of doing this is that you can get hot water at any time.
To create an electric water heater, the most important thing is to purchase a heating element. You have two options:
- Simple - buy a new item in the store. It is important to choose the right power: an ordinary network will not withstand more than 5 kW, and for a summer residence it is better to take 3-4 kW.
- Make a homemade heating element.
What you need to make a heater:
- Spiral (heating element).
- Copper tube for the manufacture of the protective case.
- Two steel tubes with ½ thread.
- Steel sheet 3 mm thick.
- Nichrome wire.
- Heat resistant glue.
- Anti-corrosion paint.
- Gas-burner.
- Welding machine.
- Bulgarian.
- Drill.
- Metal brush.
- Sharp core.
- Electrodes.
- Hammer.
How to make a heating element yourself:
- Twist the copper tube spiral. Make at least three turns spaced apart.
Twisting can cause the tubing to bend in bends. To avoid this, we recommend filling the cavity with sand and closing the edges with plugs.
- Wrap the wire tightly around the tube so that there are no gaps between the turns. Secure the ends with heat-resistant glue.
- To obtain more power, the coils are powered in parallel. With sequential power supply, heating will be worse.
- The element is then placed in a copper tube and sealed.
To accurately craft electrical appliance, you need to calculate the materials.
Calculation for the manufacture of a direct-flow heating element
It is necessary to calculate the dimensions of the future heater, how much copper wire and pipes are required.
How much wire might you need? To take a shower with normal pressure and water heating, the power must be at least 5 kW. From the calculations below, you can see the current strength:
P = IxU; I = P / U = 5000 W / 220V = 23 A
Therefore, take care of the normal wiring in the room in advance. It is better to use a cable with a thick gauge. Now calculate the indicators using the following formula:
R (maximum resistance 1.1 ohm x mm² / m) = p (wire resistance) x L / S (cross-sectional area).
How do I know the cross-sectional area? By calculation method only:
S = πr² = 3.14x0.5² = 0.8 mm²
Wire length:
L = 8.8 / 1.4 = 6.2 m
Divide this number by the number of turns of the heating element.
Let's say the dimensions of the tube are 10 mm and the thickness is 1 mm. When winding the wire parallel, the distance between the turns should be 2 mm.
How to assemble a flow heater yourself
Prepare all parts before starting assembly. The metal needs to be cleaned of rust; for this, a drill with a brush attachment is used. Keep in mind that the diameter of the sheet must exceed the dimensions of the heating element flask.
Mark the places on the sheet where the spiral will be located. Use a drill with a drill bit larger than the heater foot. Punch holes to secure the bolts. Make holes at the end of the product with a core. They should be located strictly in the middle.
Make two sketches with the grinder. Follow the diagram and markup. In the second version, the holes are not needed. As a result, you get the bottom and top part device. Then proceed like this:
- Connect the part with the holes and the tubular heating element. Make sure that all connections are tight, then weld the parts together.
- Make sure that the length of the flask does not exceed the coil size by more than 1.5 cm. Otherwise, it must be shortened.
- In the pipe, make two holes for the water supply, at the top and at the bottom.
- Weld the pipe sections with the unthreaded side facing the bulb.
For mechanical heating to work, you need to adjust the temperature. Therefore, install a thermostat next to the heating element. It is better to install the start button on the surface of the tank.
- Weld on the two bodies that were cut from the sheet.
- Install the grounding bolt inside the camera.
- Connect the device to water and run to test.
- Inspect how tightly the parts are sealed, whether there is any leakage.
- If everything is in order, turn off the device, prime and paint the surface with anti-corrosion paint.
If desired, you can organize gas or wood heating of water. But then it is better to make a storage-flow housing.
A simple home-made device is not safe, so you need to constantly monitor its operation, control the flow of water so that the heating element does not work in vain. After all, this technique does not have safety sensors.
Those who want to make a heater with their own hands do not decrease: the prices for factory-made autonomous heating devices are not encouraging, and their declared characteristics often turn out to be overestimated in comparison with the real ones. It is useless to make claims: manufacturers always have an "iron excuse" - the efficiency of heating a room is highly dependent on its heat engineering properties... Cases when it was possible to "squeeze" compensation from the manufacturer for the consequences of an accident caused by their product are also rare. True, although it is not prohibited by law to make household heaters on your own, trouble due to the fault of homemade products will be a serious aggravating circumstance for its manufacturer and owner. Therefore, this article further describes how to correctly design and manufacture safe household heaters of several systems, which are not inferior in thermal efficiency to the best industrial designs.
Constructions
Amateurs-artisans fence heaters of often very intricate design, see photo in fig. Sometimes they are neatly done. But the overwhelming most of the home-made heating devices described on the runet have one thing in common: the high degree of danger they create, harmoniously combined with the complete discrepancy of the expected technical characteristics valid. This primarily relates to reliability, durability and portability.
Make a heater for the house, household. premises or a marching autonomous for summer cottages, tourism and fishing is possible following systems(from left to right in the figure):
- With direct air heating on natural convection - electric fireplace.
- With forced blowing of the heater - fan heater.
- With indirect air heating, on natural convection or with forced blowing - oil or water-air heater.
- In the form of a surface emitting thermal (infrared, IR) rays - a thermal panel.
- Flame self-contained.
The latter differs from a stove, stove or hot water boiler in that it most often does not have a built-in burner / furnace, but uses waste heat from heating and cooking appliances. However, the line here is very blurred: gas heaters with a built-in burner are on sale and are made independently. Many of them can be used to cook or reheat food. Here, at the end, a fiery heater will also be described, which is not wood-fired, not liquid fuel, not gas-powered, and certainly not a stove. Others are considered in descending order of their safety and reliability. Which, nevertheless, with proper performance and in the "worst" samples, fully meet the requirements for household autonomous heating devices.
Thermopanel
This is a rather complicated and time-consuming, but the safest and most effective type of household electric heater: a double-sided thermal panel for 400 W, a room of 12 sq. m in concrete house heats up from +15 to +18 degrees. The power consumption of the electric fireplace in this case is 1200-1300 watts. Consumption Money for self-production of a thermal panel is small. Thermal panels work in the so-called. far (farther from the red region of the visible spectrum) or long-wavelength IR, so the heat is soft, not hot. Due to the relatively weak heating of the heat-emitting elements, if they are performed correctly (see below), the operational wear of the thermal panels is practically absent, and their durability and reliability are limited by unintended external influences.
The heat-emitting element (emitter) of the thermal panel consists of a thin flat conductor made of a material with high resistivity, sandwiched between 2 plates - plates made of a dielectric transparent to IR. Thermal panel heaters are made using thin-film technology, and the covers are made of a special plastic composite. Both are not available at home, so many amateurs try to make heat emitters based on a carbon coating sandwiched between 2 glasses (item 1 in the figure below); ordinary silicate glass is almost transparent to IR.
This technical solution is a typical surrogate, unreliable and short-lived. A conductive film is obtained either from candle soot, or by spreading an epoxy compound filled with ground graphite or electrical coal on the glass. The main drawback of both methods is the uneven film thickness. Carbon in amorphous (coal) or graphite allotropic modification is a semiconductor with high intrinsic conductivity for this class of substances. The effects characteristic of semiconductors are manifested in it weakly, almost imperceptibly. But with an increase in the temperature of the conductive layer, the electrical resistivity of the carbon film does not increase linearly, as in metals. Consequence - thin places are heated more, burn out. The current density in thicker ones grows, they heat up, they also burn out, and soon the entire film burns out. This is the so-called. avalanche burnout.
In addition, the carbon black film is very unstable and quickly crumbles by itself. In order to obtain the required power of the heater, up to 2 volumes of carbon filler must be introduced into the epoxy glue. Generally, it is possible and up to 3, and if 5-10% by volume of the plasticizer - dibutyl phthalate - is added to the resin before introducing the hardener - then up to 5 volumes of filler. But the ready-to-use (not hardened) compound turns out to be thick and viscous, like plasticine or oily clay, and it is unrealistic to apply it with a thin film - epoxy sticks to everything in the world, except for paraffinic hydrocarbons and fluoroplastic. You can make a spatula from the latter, but the compound will be pulled behind it in beds and lumps.
Finally, graphite and coal dust are very harmful to health (have you heard of silicosis from miners?) And extremely dirty substances. It is impossible to remove or wipe away their traces, soiled things have to be thrown away, they stain others. Whoever has ever dealt with graphite lubricant (this is the same finely crushed graphite) - as they say, I will live, I will not forget. That is, homemade emitters for a thermal panel must be made in some other way. Fortunately, the calculation shows that the "good old", proven over many decades and inexpensive nichrome wire is suitable for this.
Payment
Approx. 8.5 W / sq. dm IR. From the "pie" of the emitter of the thermal panel, 17 watts will go in both directions. Let's set the dimensions of the emitter 10x7 cm (0.7 sq. Dm), such pieces can be cut from scrap and cutting waste in almost unlimited quantities. Then one emitter will give us a room of 11.9 watts.
Let's take a heater power of 500 W (see above). Then you need 500 / 11.9 = 42.01 or 42 emitters. Structurally, the panel will represent a matrix of 6x7 emitters with dimensions without framing 600x490 mm. We put on the frame up to 750x550 mm - it is quite compact in terms of ergonomics.
The current consumed from the mains is 500 W / 220 V = 2.27 A. Electrical resistance the entire heater - 220 V / 2.27 A = 96.97 or 97 Ohm (Ohm's law). The resistance of one emitter is 97 Ohm / 42 = 2.31 Ohm. The resistivity of nichrome is almost exactly 1.0 (Ohm * sq. Mm) / m, but what section and length of wire is needed for one emitter? Will the nichrome "snake" (item 2 in the figure) fit between the 10x7 cm glasses?
The current density in open, i.e. contacting with air, nichrome electric spirals - 12-18 A / sq. mm. At the same time, they glow from dark to light red (600-800 degrees Celsius). Let's take 700 degrees at a current density of 16 A / sq. mm. Under the condition of free IR radiation, the temperature of nichrome depends on the current density approximately by the square root. Let's reduce it by half, to 8 A / sq. mm, we get the working temperature of nichrome at 700 / (2 ^ 2) = 175 degrees, it is safe for silicate glass. In this case, the temperature of the outer surface of the emitter (excluding heat dissipation due to convection) will not exceed 70 degrees with the outer surface at 20 degrees - it is suitable both for heat transfer by "soft" IR, and for safety, if you cover the emitting surfaces with a protective mesh (see below).
A nominal operating current of 2.27 A will give a nichrome cross-section of 2.27 / 8 = 0.28375 sq. mm. According to the school formula for the area of a circle, we find the diameter of the wire - 0.601 or 0.6 mm. With a margin, let's take it 0.7 mm, then the power of the heater will be 460 W, because it depends on its operating current squared. 460 W is enough for heating, 400 W would be enough, and the durability of the device will increase several times.
1 m of nichrome wire with a diameter of 0.7 mm has a resistance of 2.041 Ohm (0.7 squared = 0.49; 1 / 0.49 = 2.0408 ...). To obtain the resistance of one emitter of 2.31 ohms, you need 2.31 / 2.041 = 1.132 ... or 1.13 m of wire. Let's take the width of the nichrome "snake" at 5 cm (1 cm of stock from the edges). Add 2.5 mm to the turn of 1 mm nails (see below), for a total of 5.25 cm per snake branch. Branches will need 113 cm / 5.25 cm = 21.52 ..., we will accept 21.5 branches. Their total width is 22x0.07 cm (wire diameter) = 1.54 cm.Let's take a snake length of 8 cm (1 cm of stock from short edges), then the wire laying ratio is 1.54 / 8 = 0.1925. In the lousy Chinese low-power power transformers, it is approx. 0.25, i.e. we have enough space for the bends and gaps between the branches of the snake. Uf-f, fundamental issues have been resolved, we can proceed to R&D (development work) and technical design.
OCD
Thermal conductivity and transparency for IR silicate glass vary greatly from brand to brand and from batch to batch. Therefore, you will first need to make 1 (one) emitter, see below, and test it. Depending on their result, it may be necessary to change the diameter of the wire, so do not buy a lot of nichrome at once. This will change the rated current and power of the heater:
- Wire 0.5 mm - 1.6 A, 350 W.
- Wire 0.6 mm - 1.9 A, 420 W.
- Wire 0.7 mm - 2.27 A, 500 W.
- Wire 0.8 mm - 2.4 A, 530 W.
- Wire 0.9 mm - 2.6 A, 570 W.
Note: who is literate in electricity - the rated current, as you can see, does not change according to the square of the wire diameter. Why? On the one hand, thin wires have a relatively large radiating surface. On the other hand, with a thick wire, the permissible IR power transmitted by the glass must not be exceeded.
For testing, the finished sample is installed vertically, propped up with something non-combustible and heat-resistant, on a non-combustible surface. Then, a rated current is supplied to it from a regulated power supply (IP) of 3 A or more, or LATRa. In the latter case, it is impossible to leave the sample unattended during the entire test! The current is controlled by a digital tester, the probes of which must be tightly compressed with the live wires with a screw and nut and washers. If the prototype is powered by LATR, the tester should measure the AC current (AC 3A or AC 5A limit).
First of all, you need to check how the glass behaves. If it overheats and cracks within 20-30 minutes, then the entire batch may be unusable. For example, dust and dirt eats into used glass over time. Cutting them is sheer torment and death diamond glass cutter... And such glasses crack at much weaker heating than new ones of the same type.
Then, after 1-1.5 hours, the strength of the IR radiation is checked. The temperature of the glass is not an indicator here, because the main part of IR emits nichrome. Since you most likely will not have a photometer with an IR filter, you will have to check with your palms: they are kept parallel to the emitting surfaces at a distance of approx. 15 cm away from them for at least 3 minutes. Then, for 5-10 minutes, an even soft warmth should be felt. If the IR from the emitter begins to burn the skin immediately, the diameter of the nichrome is reduced. If, after 15-20 minutes, a slight burning sensation (as on a sunny heating in the middle of summer) is not felt, nichrome should be taken thicker.
How to bend a snake
The device of the emitter of a homemade panel heater is given in pos. 2 fig. above; nichrome snake is shown conditionally. Cut-to-size glass covers are cleaned of dirt and washed with a brush in water with the addition of any dishwashing detergent, then they are also washed with a brush under running clean water. "Ears" - contact lamellas measuring 25x50 mm made of copper foil - are glued to one of the plates with epoxy glue or instant cyanoacrylate (superglue). Approach of the "ear" to the lining - 5 mm; sticking out 20 mm. So that the lamella does not fall off until the glue has set, something 3 mm thick is placed under it (the thickness of the glass cover).
Next, you need to form the very snake from nichrome wire. This is done on a template-mandrel, the diagram of which is given in pos. 3, a detailed drawing- in fig. here. "Ponytails" for annealing the snake (see below) must be given from 5 cm. The bitten ends of the nails are ground to roundness on an emery stone, otherwise it will be impossible to remove the finished snake without crushing it.
Nichrome is quite elastic, because the wire wound on the template must be annealed so that the snake keeps its shape. This should be done in semi-darkness or low light. A voltage of 5-6 V is applied to the snake from the IP for at least 3 A (this is why a fire-resistant pad is needed on a tree). When the nichrome lights up cherry, the current is turned off, the threads are allowed to cool completely, and this procedure is repeated 3-4 times.
The next step is to press the snake with your fingers through the plywood strip superimposed on it and carefully unwind the tails wound on 2-mm nails. Each tail is straightened and shaped: a quarter of a turn remains on a 2-mm nail, and the rest is cut flush at the edge of the template. The remainder of the "tail" of 5 mm is cleaned with a sharp knife.
Now the snake must be removed from the mandrel, without twisting it, and fixed on the substrate, ensuring reliable electrical contact of the leads with the lamellas. They are removed with a pair of knives: their blades are slipped from the outside under the bends of the branches on 1-mm nails, gently pry and lift the crimped thread of the heater. Then the snake is placed on a substrate and slightly bent, if required, the leads so that they lie approx. in the middle of the slats.
Nichrome is not soldered with metal solders with an inactive flux, and the remnants of the active flux can eventually corrode the contact. Therefore, nichrome to copper is "soldered" so-called. liquid solder - conductive paste; it is sold in radio stores. A drop of liquid solder is squeezed out onto the contact of the stripped nichrome with copper and pressed through a piece of plastic film with a finger so that the paste does not protrude upward from the wire. You can immediately press down with a flat weight instead of a finger. Remove the load and the film after the paste has hardened, from an hour to a day (the time is indicated on the tube).
The "solder" is frozen - it's time to assemble the emitter. Along the middle we squeeze out a thin, not thicker than 1.5 mm, "sausage" of the usual construction silicone sealant, this will prevent the wire bends from slipping and snagging. After that, the same sealant is squeezed out with a roller thicker, 3-4 mm, along the contour of the substrate, stepping back from the edge by approx. by 5 mm. We apply a cover glass and very carefully so that it does not slide sideways and pull the snake along with it, press it down until it lies tightly, and put the emitter to dry.
The drying rate of silicone is 2 mm per day, but after 3-4 days, as it may seem, it is still impossible to take the emitter further into work, you need to let the inner roller that fixes the bends dry. It will take approx. a week. If a lot of radiators are already being made for a working heater, they can be stacked dry. The bottom layer is laid out on plastic wrap, it is covered with it from above. Elements trail. layers are laid across the underlying, etc., separating the layers with a film. The stack is to dry for 2 weeks for a guarantee. After drying, the excess silicone that has come out is cut off with a safety razor blade or a sharp assembly knife... Silicone beads must also be completely removed from the contact lamellas, see below!
Installation
While the emitters are drying, we make from strips solid wood(oak, beech, hornbeam) 2 identical frames (item 4 in the figure with the panel heater diagram). Connections are made by cutting in half a tree and fastened with small self-tapping screws. MFD, plywood and wood materials on synthetic binders (chipboard, OSB) are not suitable, because prolonged heating, albeit not strong, is categorically contraindicated for them. If you have the opportunity to cut out details of frames from textolite or fiberglass - generally excellent, but ebonite, bakelite, textolite, carbolite and thermoplastic plastics are unsuitable. Before assembly, wooden parts are twice impregnated with a water-polymer emulsion or a water-based acrylic varnish diluted by half.
Ready-made emitters (pos. 5) are placed in one of the frames. Overlapping lamellas are electrically connected by drops of liquid solder, as are the bridges on the sidewalls that form serial connection all emitters. It is better to solder the lead wires (from 0.75 sq. Mm) with ordinary low-melting solder (eg POS-61) with an inactive flux paste (composition: rosin, ethyl alcohol, lanolin, see on the bottle or tube). Soldering iron - 60-80 W, but you need to solder quickly so that the emitter does not unstick.
The next step at this stage is to impose a second frame and mark on it where the lead wires came, you will need to cut grooves under them. After that, we assemble the frame with emitters on small self-tapping screws, pos. 6. Take a closer look at the location of the attachment points: they should not fall on live parts, otherwise the heads of the fasteners will be energized! Also, in order to exclude accidental touching the edges of the lamellas, all ends of the panel are pasted over with non-combustible plastic with a thickness of 1 mm, for example. PVC filled with chalk from cable channels(boxes for wiring). For the same purpose, and for greater structural strength, silicone sealant is applied to all glass joints with frame parts.
The final steps are, firstly, the installation of legs with a height of 100 mm. A sketch of the wooden leg of the panel heater is given in pos. 7. The second is the imposition of a protective steel mesh made of thin wire with a mesh of 3-5 mm on the sidewalls of the panel. The third is the design of the cable gland with a plastic box: it houses the contact terminals and a light indicator. Possibly - thyristor voltage regulator and protective thermostat. Everything, you can turn on and warm up.
Thermal picture
If the power of the described thermal panel does not exceed 350 W, you can make a picture heater from it. To do this, foil-insol is applied to the back side, the same one that is used for thermal insulation. Its foil side should face the panel, and its porous plastic side should face outward. Front side the heater is made out with a fragment of photo wallpaper on plastic; thin plastic is not so hot what an obstacle to IR. In order for the picture-heater to warm up better, you need to hang it on the wall at an angle of approx. 20 degrees.
And the foil?
As you can see, a homemade panel heater is a rather laborious process. Is it possible to simplify the work by using, say, aluminum foil instead of nichrome? Foil thickness of the baking sleeve approx. 0.1 mm, it seems to be a thin film. No, it's not about the thickness of the film, but about resistivity her material. For aluminum, it is low, 0.028 (Ohm * sq. Mm) / m. Without giving detailed (and very boring) calculations, we will indicate their result: the area of a thermal panel for a power of 500 W on an aluminum film 0.1 mm thick turns out to be almost 4 square meters. m. Tolstovata still turned out to be a film.
12 in
A homemade fan heater can be quite safe in a low-voltage 12 V version. Power over 150-200 W cannot be achieved from it; too large, heavy and expensive will need a step-down transformer or power supply. However, 100-120 W is just enough to keep a small plus in the basement or cellar all winter, which guarantees against frozen vegetables and jars with homemade preparations bursting from frost, and 12 V is the voltage allowed in rooms with any degree of danger of electric shock. Anything bigger cannot be served in the basement / cellar, because they are especially dangerous according to the electrical classification.
The basis of a 12 V fan heater is an ordinary red working hollow (hollow) brick. Best of all, one and a half 88 mm thick (top left in the figure) is suitable, but a double thickness of 125 mm will also work (same place below). The main thing is that the voids are end-to-end and the same.
The device of a "brick" fan heater for 12 V for the basement is given in the same place in Fig. Let's count nichrome heating spirals for it. We take a power of 120 W, this is with some margin. Current, respectively, 10 A, heater resistance 1.2 Ohm. On the one hand, the spirals are blown through. On the other hand, this heater must work unattended for a long time in rather difficult conditions. Therefore, it is better to turn on all the spirals in parallel: one will burn out, the rest will be stretched. And it is convenient to adjust the power - it is enough to turn off 1-2 or several spirals.
There are 24 channels in the hollow brick. The spiral current of each channel is 10/24 = 0.42 A. It is not enough, nichrome is needed very thin and, therefore, unreliable. This option would fit for a household fan heater up to 1 kW or more. Then the heater must be calculated, as described above, for a current density of 12-15 A / sq. mm, and divide the resulting length of the wire by 24. To each piece, add 20 cm by 10 cm connecting "tails", and the middle is twisted into a spiral with a diameter of 15-25 mm. With "tails" all spirals are connected in series using copper foil clamps: its tape 30-35 mm wide is wound in 2-3 layers on folded nichrome wires and twisted 3-5 turns with a pair of small pliers. To power the fans, you will have to install a low-power 12 V transformer. Such a heater is well suited for a garage or warming up a car before a trip: like all fan heaters, it quickly warms up the middle of the room without wasting heat on heat loss through the walls.
Note: Computer fans are often called coolers (lit. - coolers). In fact, a cooler is all about a cooling device. For example, a processor cooler is a finned heatsink in a block with a fan. And he is a fan in himself, and in America he is a fan.
But back to the basement. Let's see how much nichrome is needed for reduced to 10 A / sq. mm for reasons of reliability, the current density. Wire cross-section, clearly without calculations - 1 sq. mm. Diameter, see calculations above - 1.3 mm. Such nichrome is on sale without difficulty. The required length for a resistance of 1.2 Ohm is 1.2 m. And what is the total length of the channels in the brick? We take one and a half thickness (weighs less), 0.088 m. 0.088x24 = 2.188. So we just need to pass a piece of nichrome through the voids of the brick. It is possible through one, tk. according to the calculation, you need 1.2 / 0.088 = 13, (67), i.e. 14 is enough. So they warmed up the basement. And it is quite reliable - such a thick nichrome and strong acid will not quickly corrode.
Note: the brick in the body is fixed with small steel corners on bolts. In a powerful 12 V circuit, an automatic protective device e.g. automatic plug for 25 A. Inexpensive and quite reliable.
IP and UPS
It is better to take (make) a transformer on iron for heating the basement with powerful winding taps at 6, 9, 12, 15 and 18 V, this will allow you to regulate the heating power over a wide range. 1.2 mm nichrome with blowing will pull 25-30 A. To power the fans, then you need a separate winding for 12 V 0.5 A and also a separate cable with thin veins. To power the heater, you need wires from 3.5 sq. mm. A powerful cable can be the most shoddy - PUNP, KG, 12 V leaks and breakdown can not be feared.
Maybe you do not have the opportunity to use a step-down transformer, but a switching power supply unit (UPS) from an unusable computer was lying around. Its 5 V channel is sufficient in terms of power; the standard is 5 V 20 A. Then, firstly, you need to recalculate the heater for 5 V and the power of 85-90 W, so as not to overload the UPS (the wire diameter is 1.8 mm; the length is the same). Secondly, to supply 5 V, you need to connect together all the red wires (+5 V) and the same number of black ones (common wire GND). 12V for fans is taken from any yellow wire(+ 12V) and any black. Thirdly, you need to short-circuit the PC-ON logical start circuit to the common wire, otherwise the UPS simply will not turn on. Usually the PC-ON wire is green, but you need to check: remove the cover from the UPS and look at the markings on the board, from the top or from the mounting side.
Heating elements
For heaters, trace. types will have to buy heating elements: electrical appliances for 220 V with open heaters are extremely dangerous. Here, excuse the expression, you need to think first of all about your own skin with property, whether there is a formal ban or not. With 12-volt devices it is easier: according to statistics, the degree of danger decreases in proportion to the square of the ratio of supply voltages.
If you already have an electric fireplace, but the heating is not good enough, it makes sense to replace a simple air heating element with a smooth surface (item 1 in the figure) with a ribbed one, pos. 2. The nature of convection will then change significantly (see below) and heating will improve when the power of the finned heating element is 80-85% of the smooth one.
Cartridge heating element in a case made of of stainless steel(pos. 3) can heat both water and oil in a tank made of any construction material. If you take this one, be sure to check that the kit includes gaskets made of oil-thermo-petrol resistant rubber or silicone.
The copper water heater for the boiler is supplied with a tube for the temperature sensor and a magnesium protector, pos. 4 which is good. But they can only heat water and only in a stainless steel or enameled tank. The heat capacity of the oil is much less than that of water, and in the oil the body of the copper heating element will soon burn out. The consequences - to the hardest and fatal. If the tank is made of aluminum or ordinary structural steel, then electrocorrosion due to the presence of a contact potential difference of metals will very quickly eat up the protector, and after that it will eat through the heating element body.
T. called. dry heating elements (pos. 5), like cartridge heaters, are capable of heating both oil and water without additional protection measures. In addition, their heating element can be changed without opening the tank and without draining the liquid from there. There is only one drawback - they are very expensive.
Fireplace
You can improve a conventional electric fireplace, or make your own efficient one based on a purchased heating element, using an additional casing that creates a secondary convection circuit. From a conventional electric fireplace, firstly, the air goes up in a rather hot, but weak stream. She quickly rises to the ceiling and warms through it more than the floor of the neighbors, the attic or the roof than the master's room. Secondly, the IK going down from the heating element in the same way heats the neighbors from below, the subfloor or basement.
In the construction shown in fig. on the right, downward-facing IR is reflected into the outer casing and heats the air in it. The thrust is further enhanced by the suction of hot air from the inner casing, which is less heated from the outer one in the constriction of the latter. As a result, the air from the electric fireplace with a double convection circuit comes out in a wide, moderately heated stream, spreads to the sides, not reaching the ceiling, and effectively heats the room.
Oil and water
The effect described above is also given by oil and water-air heaters, which is why they are popular. Oil heaters industrial production are made sealed with a non-replaceable filling, but it is by no means recommended to repeat it yourself. Without an accurate calculation of the volume of the case, internal convection in it and the degree of filling with oil, a rupture of the case, a power failure, oil outflow and ignition is possible. Underfilling is just as dangerous as overfilling: in the latter case, the oil simply tears the body with pressure when heated, and in the first it first boils. If you make a case of a deliberately larger volume, then the heater will heat up disproportionately weakly in comparison with electricity consumption.
In amateur conditions, it is possible to build an open-type oil or water-air heater with an expansion tank. A diagram of its device is shown in Fig. Once upon a time, quite a few of these were made, for garages. The air from the radiator goes weakly heated, the temperature difference between the inside and outside is kept to a minimum, which is why the heat loss is also reduced. But with the advent of panel heaters, homemade oil products are coming to naught: thermal panels are better in all respects and are quite safe.
If you do decide to make yourself an oil heater, keep in mind that it must be reliably grounded, and you only need to fill it with very expensive transformer oil. Any liquid oil is gradually bituminized. An increase in temperature speeds up this process. Engine oils are formulated with the oil circulating among moving parts due to vibration. Bituminous particles in it form a suspension, only polluting the oil, which is why it has to be changed from time to time. In the heater, nothing will prevent them from depositing carbon deposits on the heating element and in the tubes, which causes the heating element to overheat. If it bursts, the consequences of accidents oil heaters are almost always very hard. Transformer oil is expensive because the bituminous particles in it do not settle into carbon deposits. There are few sources of raw materials for mineral transformer oil in the world, and the cost of synthetic oil is high.
Fiery
Powerful gas heaters for large premises with catalytic afterburning are expensive, but record-breaking economical and efficient. It is impossible to reproduce them in amateur conditions: you need a micro-perforated ceramic plate with platinum sputtering in the pores and a special burner made of parts made with precision precision. At retail, one or the other will cost more than a new heater with a guarantee.
Tourists, hunters and fishermen have long come up with low-power afterburners in the form of an attachment to a camp stove stove. These are also produced on an industrial scale, pos. 1 in fig. Their efficiency is not so hot, but it is enough to warm up the tent before lights out in sleeping bags. The design of the afterburner is rather complicated (item 2), which is why factory tent heaters are not cheap. Lovers of these also make a lot, from cans or, for example. from automobile oil filters. In this case, the heater can operate both from a gas flame and from a candle, see video:
Video: Portable Oil Filter Heaters
With the advent of heat-resistant and heat-resistant steels in wide use, nature lovers increasingly prefer gas camping heaters with afterburning on a grid, pos. 3 and 4 - they are more economical and heat better. And again, amateur creativity combined both options into a mini-heater. combined type, pos. 5.Capable of working on and off gas burner, and from the candle.
A drawing of a homemade mini-heater for afterburning is shown in Fig. on right. If it is used sporadically or temporarily, it can be made entirely from cans. Banks from tomato paste etc. Replacing the perforated mesh cover significantly reduces the warm-up time and fuel consumption. The larger and very durable version can be assembled from car drives, see next. video clip. This is already considering that the stove, tk. you can cook on it.
Video: heater-stove from a wheel disk
From the candle
A lighting candle, by the way, is a pretty strong source of heat. For a long time, this property of her was considered a hindrance: in the old days, at balls, ladies and gentlemen were drenched in sweat, cosmetics flowed, powder clumped together. It is difficult for a modern person to understand how they also played cupids after that, without hot running water and a shower.
The heat from a candle in a cold room is wasted for the same reason that a single-circuit convection heater does not heat well: hot exhaust gases rise too quickly and cool down, giving soot. Meanwhile, it is easier to make them burn out and give heat than a gas flame, see fig. In this system, the 3-circuit afterburner is assembled from ceramic flower pots; burnt clay is a good IR emitter. The heater on the candle is intended for local heating, for example, so as not to tremble while sitting at the computer, but the heat from just one candle gives surprisingly much. It is only necessary, using it, to open the window, and when going to bed it is imperative to extinguish the candle: it also consumes a lot of oxygen for combustion.
Anyone can assemble an electric boiler with their own hands - by operational characteristics prefabricated units are not much inferior to factory products. With a responsible approach, a homemade boiler can be even more reliable and durable than a factory-made machine.
This also applies to electric boilers for heating a private house, known for their economy and high performance. Parts for assembling such equipment are widely available, and the manufacturing process itself can be cheaper than buying a finished device.
Homemade boiler classification
There are three types of electric boilers. The first option is working on heating elements. They are equipped with a tubular electric heater, which, under the action of electricity, heats up and transfers heat to the liquid. The heater is insulated so that the heating medium is not energized.
The second option is inductive action. It is equipped with a winding transformer, with the heating pipe acting as an induction coil. Heating of the coolant occurs due to eddy currents arising in the winding.
Finally, the third option, electrode - the liquid is not only a heat carrier, but is also an integral part of the electrical system. It is quite simple to assemble an electrode boiler with your own hands, but high requirements are imposed on the electrical safety of this equipment.
Design
In fact, a homemade electric boiler is a piece of pipe with built-in electrical fittings. This is very convenient, especially if you make the unit removable: then the maintenance and service of the equipment will be greatly simplified.
If you place the unit not in a pipe, but in a separate housing, then you can install additional sensors that will automate the operation of the heating system, increase efficiency and reduce energy consumption. In addition, when it is necessary to replace the boiler with another, it will be possible to do this without violating the integrity of the system circuit.
Difficulties of operation
The disadvantage of any electric heater is the danger of exceeding the limit for connecting electrical equipment in a private house. So, the total power of all electrical appliances used in a home should not be more than 15 kW.
To service a private house with an area of about 100 m2, an aggregate with a capacity of at least 10 kW is required.
Therefore, by connecting an electric boiler with your own hands, you divert only 5 KW of energy to the use of other devices. To increase the consumption limit, you need to obtain a special permit.
To make a homemade electric heating boiler with a tubular electric heater, you will need the following set of materials:
- steel sheet with a thickness of more than 2 mm;
- a piece of steel pipe (length and diameter depend on the capacity of the unit);
- three-phase heating elements (it is not recommended to use heaters with a built-in relay, as they wear out quickly).
First, the future bottom of the boiler must be cut out of the steel sheet. The bottom dimensions must correspond to the pipe diameter. Then, from the same metal, it is required to make a flange - a ring whose inner diameter is equal to the outer or inner diameter pipes, depending on how the part is planned to be fixed to the body. The ring width is usually 30 mm.
Further, a cover with a diameter corresponding to the outer diameter of the flange is made from a steel sheet. The cover and the flange are connected with 6 bolts, holes are made in advance in the places where the fasteners are installed. Several more holes are drilled in the lid - their size should correspond to the size of the heating elements planned for installation.
The bottom should be welded to the boiler body first, and the flange should be welded next. The cover is mounted only after the tubular heaters are firmly fixed on it. A sealing gasket made of a material resistant to water is inserted between the heating elements and the cover.
Between the cover and the flange, there is another gasket made from an automobile inner tube. This gasket must be an exact replica of the flange, including bolt holes.
Installation of branch pipes
Before closing the boiler with a lid, fittings are installed in its body for connecting pipes of the heating system, having previously cut out suitable holes. It is important that there is a thread at the ends of the nozzles: this is required for the installation of inlet taps, which will block the circulation of the coolant in the circuit if the electric boiler needs to be repaired. A pipe for draining hot liquid is located at the top of the unit; it is advisable to build it directly into the cover. The cooled heat carrier is fed through the pipe from the bottom.
When the pipes are installed, the boiler is completely assembled and connected to the network. Sometimes its design can change: for example, not only the cover, but also the bottom is mounted on the flange. The device is versatile and easy to adapt to technical parameters home heating systems.
Electric installation work
During electrical work, the contacts of all the heating elements of the boiler are connected to the block, and the neutral wire is connected to it. Sometimes heating elements are immediately short-circuited to this wire without using a block.
The cross-section of the wire core must correspond to the load that the heating elements create: then the home-made electrical unit will work without failures.
A phase wire is connected to the contact of each heater, passed through the circuit breaker. The cable cross-section is selected based on the load created by all the included heating elements at the same time.
All wires must be insulated, special attention must be paid to ensure that their bare parts do not come into contact with the metal cover of the boiler.
To make an induction boiler you will need:
- a piece of plastic pipe with thick walls;
- copper wire with a diameter of 7 mm;
- welding inverter with a power of 15 A.
TO plastic pipe fix two nozzles, having previously made the corresponding holes. Its internal space is completely filled with wire cuttings 40-50 mm long.
Then an induction coil is created: the wire is carefully wrapped around the pipe, the total number of turns is about 90. The coil is connected to the inverter. The resulting homemade heating boiler is mounted directly into the pipeline by cutting out a section of the pipe.
Assembling the electrode boiler
It is also easy to make an electrode heater. To do this, the master will need:
- iron pipe with a diameter of 57 mm with thick walls;
- iron sheet with a thickness of more than 2 mm;
- inner electrode with a diameter of 25 mm;
- gaskets made of paronite or rubber and connecting clamps.
As in the previous cases, you need to start by connecting the pipe fittings to the future boiler drum. From one end, the pipes are welded to the unit, from the other, they are threaded.
Making an electrode boiler with your own hands, a hole is drilled in the body for a plug. An electrode is attached to the latter; it is installed inside the boiler. At the final stage homemade case welded by installing a lid and a bottom cut from an iron sheet.
After cleaning welds it is required to check them for permeability. For this, the welding places are covered with soapy foam, and pressure is generated inside the housing with an air press. Where bubbles appear, the boiler will leak. When all the identified faults have been eliminated, the body can be treated with enamel paint.
The boiler will work properly if the water in the heating system of the house contains soda. The latter is added in order to increase the current strength: you can calculate this indicator by dividing the power of the unit by 220.
Build a heating boiler in country houses, which are not connected to the central gas pipeline, it is quite possible even on their own. In this material, we will talk about how to make an electric heating boiler with your own hands. We will consider 3 available options for electric boilers - heating elements, electrode and induction.
What tools will be needed
In order to assemble homemade electric heating and face the minimum of hassle, you need to have quality tools at your disposal.
For work you will need:
- welding machine - it is most convenient to work with an inverter model;
- torch - if you do not know how to use a gas torch, it is better to use a plasma one;
- grinder - you will even need 2 models - a large one for a disc with a section of 230 mm and a small one for a disc with a section of 125 mm;
- electric drill;
- hammer;
- core;
- tape measure and compasses.
Electric boiler on heating elements
Diagram of an electric boiler with a do-it-yourself tenom is the simplest to execute and has been known for a long time.
The principle of operation of the heating element boiler
The device of all household appliances, in which heating elements (heating elements) are installed, is the same. When the power is turned on, the voltage is supplied to the heating element, which gradually heats up and transfers the thermal energy to the liquid located around it.
The advantages of such devices:
- a wide range of heating elements of various shapes and powers;
- the ability to use in any heating system with liquid heat transfer agents;
- insulation is installed on the boiler body, so that the voltage is supplied exclusively to the heating element;
- do not require complex maintenance;
- the heating level is very easy to control, even with minimal set automatic controls.
Among the disadvantages of a homemade electric boiler of this type are:
- "Gluttony" in the consumption of electricity, since it takes 1 kW of power to heat 10 m2 of area;
- impurities in the coolant accumulate on the heating element in the form of scale, so it must be cleaned about 1 time per year;
- The heating element can function only in the presence of liquid; it is recommended to install an idle speed sensor with it.
The procedure for assembling a boiler with heating elements with its own rivers
Before making an electric boiler with your own hands, you should take care of the availability of a reliable power line. Only equipment with a capacity of no more than 6 kW can be connected to ordinary networks with a voltage of 220 V and a frequency of 50 Hz. If a more powerful boiler is required, a three-phase wiring and a separate input must be made for it.
So, we start assembling a homemade electric heating boiler from a pipe with a cross section of 159 mm with a wall thickness of 10 mm. This pipe will serve as the boiler drum. For it, you will need either a factory-made hemisphere with a section of 159 mm and a thickness of 10 mm, or sheet metal with a thickness of 8 mm and more of a similar section.
The roof of the boiler, into which the heating elements will subsequently be embedded, can be made from a channel with a thickness of 8 mm.
We cut a ¾ inch sleeve into the boiler dome. We will screw the drain valve into this sleeve. In addition, you will need 2 1-inch pipes for inflow and return. The threads on the branch pipes can be made both internal and external. It all depends on which one is more convenient for you to work with.
To relieve excess pressure, you need to prepare a branch pipe for the tie-in of the bypass channel. You will also need 3 adapters, into each of which a heating element for an electric boiler will be screwed. One more adapter will be needed for the thermal sensor. In addition, you will need holders for automation.
Please note that it is advisable to cut the threads on the pipes and adapters immediately.
Prepared threaded pipes, the same as on heating elements, must be immediately screwed into the adapters. This is necessary so that the thread is not damaged during welding to the roof. To mark the insertion points of heating elements, the outer diameter of the pipe must be divided into 6 equal sectors according to the size of the radius. Then we draw three identical sectors strictly at an angle of 120 °.
The next step is to start cutting. Having finished with the markings, using a plasma cutter, cut out the holes for the pipes for the heating elements. They should only be cut along the outer contour. With all other connections, this is not critical.
Let's start welding. First, we intercept the pipes at several points so that they are not led. Then we check the accuracy of the position, if necessary, tap it lightly with a hammer, and then make a continuous seam. It is important that the adapters for heating elements in an electric boiler for heating with their own hands protrude 1 cm above the surface of the boiler arch.
We proceed to cutting the arch from the channel. In its center we make a hole for the air valve branch pipe, after which we weld the branch pipe itself. On the side we make a hole for the temperature sensor and also weld the pipe under it.
All protrusions, burrs and remnants of welding work must be carefully cleaned with a grinder. The inner surface of the vault platform should be perfectly flat. The pipes for installing heating elements will protrude only 1 cm from the outside.
We have got a rather powerful electric boiler with our own hands with 3 heating elements. If you need a simpler unit, according to the same principle, it can be assembled for 1 or 2 heating elements.
Assembling a heating boiler on electrodes
Devices of this type began to be actively used only in the last 10-15 years. These are more technological devices in comparison with heating elements.
Design
In electronic electric boilers, the liquid acts as a heating element. A self-assembled electric boiler of this type is a metal case, inside which an insulated steel electrode is located.
0 is supplied to the body, and a phase is applied to the electrode. When the voltage is applied, the water ions begin to oscillate at a frequency of 50 hertz. In this case, the liquid gradually heats up. Due to this property, such boilers are also called ionic.
The dimensions of the electrode boilers are small. They can be made from a pipe with a cross section of up to 320 mm and a length of up to 60 cm.However, an electric boiler for heating a house with your own hands can be made much smaller.
Advantages:
- small dimensions, thanks to which the ion boiler can be placed even in small apartment;
- the absence of the so-called "dry run", which guarantees the boiler's serviceability, since without liquid inside it will not work;
- resistance to voltage drops;
- high speed of heating and cooling, which means ease of adjustment;
- efficiency in electricity consumption in comparison with devices on heating elements.
Among the disadvantages of such boilers are the following points:
- an important condition for the effective functioning of the electrode boiler is the level of thermal conductivity and the quality of the heat carrier;
- the device must be reliably grounded as there is a high risk of injury electric shock;
- it is important to exclude the possibility of air entering the system, otherwise, the electrodes will become unusable due to corrosion.
Assembly instructions for a homemade electrode boiler
As a body for an electric heating boiler with our own hands, we use a pipe with an internal section of about 50 mm and a length of 40 cm.In addition, you will need a solid rod with a diameter of 20 mm and a length of 30 cm, as well as two adapters with a cut internal thread... At the end of the rod, we drill a blind hole with a thread for a Ø10 mm bolt.
We prepare the pipes. 1 we will weld at the end of the pipe, and the other at the side. To make the side pipe fit perfectly to the pipe, it is cut with a grinder, and then polished with a round file.
We cut the holes for the pipes. If no cutter is available, many small holes can be drilled around the circumference. The work is brought to the ideal with a file and a round file. The hole for the side pipe must be located 10-15 mm from the edge of the pipe.
The next step is to weld the pipes to the pipe. To prevent them from being led, first they do spot welding in several places, and then they impose a continuous seam.
We are preparing a platform for an electric boiler. To do this, you can take a sheet of fiberglass with a thickness of 2 cm and cut a piece of 120 × 120 mm using a metal hacksaw. Then, in this platform, you need to drill one hole in the center, and four holes around the perimeter. The cross-section of the holes should be 10-12 mm.
Through the holes along the perimeter, the fixings of the boiler body will be passed, and the central hole is intended for fixing the steel electrode.
We proceed to fixing the boiler body to the platform. To ensure a secure fit, four Ø12mm nuts can be welded to the body on 4 sides. Bolts Ø10 mm will easily pass through them.
These nuts must be welded with a slight offset from the platform. To ensure it, it is necessary to screw the nuts of suitable size onto the bolts, thread them into wide nuts, and fix them again with smaller ones from below. Thus, it will be easier to carry out the welding work.
On the the last stage we carry out final assembly boiler. To do this, we cut out a rubber gasket with a section slightly larger than the outer diameter of the boiler. In its central part we make a hole and pass an electrode through it. Then we install the body on the platform and screw it on.
Induction boilers
Among all the options for assembling heating with an electric boiler with your own hands, the manufacture of an induction-type model is the most innovative.
Electric induction boiler working principle
If we omit the details, then the operation of an induction boiler is based on heating the coolant by means of a magnetic field.
Among the advantages of such units:
- high efficiency;
- safety;
- the ability to use any coolant;
- lack of scale.
- the high cost of factory boilers;
- the complexity of the structure of the automatic control unit. It will be difficult to assemble it without preparation.
Assembly instructions for a homemade induction boiler
It is worth noting that often the instruction on how to make an induction-type electric boiler is so complicated and contains such time-consuming drawings that self-assembly hardware looks pretty dubious. However, we found a non-standard solution.
Before you make an electric boiler for heating yourself, you will need to purchase an induction oven with a power of 2.4 kW and 3 meters of profiled pipes Ø25 × 50 mm with walls 2.5 mm thick.
If we consider how this structure will work, then first we collect a flat container from the profile - liquid will move along it. And then we fix the induction stove to the pipe and connect it to the network. Everything together will look like a saucepan on the stove.
The pipe must be cut as accurately as possible. You will need several pieces of 400 mm, carefully deburred at the ends.
Since the liquid inside such a boiler will move like a snake, it is advisable to take an even number of pieces of pipe so that the inlet and outlet are located on the same side - so it is more convenient to connect them to the heating circuit.
Since the profile pipes are not perfectly straight, they must first be joined by blunt edges with sharp ones and numbered so as not to be confused later.
At the next stage, the joints between the pipes must be boiled. We put the structure on flat surface, tighten with a clamp and weld. First, we do spot welding so that the structure does not lead, and then we carry out major seams.
Now we need to close the end of our container. For this we use a steel strip cut from profiled pipes. We carry out welding in a similar way - first pointwise, and then overhaul.
We also weld the strip on the opposite side, not forgetting to install the inlet and return pipes on the outer pipes. To ensure the maximum contact area of the container with the stove, all seams must be carefully cleaned.
In order for our boiler to be hung on the wall, 2 corners must be welded on its back, in which the induction stove will be placed, as well as hinges for hanging.
The last stage of work is painting. Heat resistant paint can be used. This completes the assembly work. You can hang up the boiler and connect it to heating and electricity.
When buying an induction oven, make sure it is designed for continuous operation. Otherwise, a system restart is required every 2 hours.
Outcomes
Each of the listed models is fully functional and reliable. Everyone will make the choice in favor of any of them independently. The main thing is to pay close attention to the work and, in case of difficulty, consult with knowledgeable people.