The technology of manufacturing a sauna stove makes special demands on the equipment of all its departments, including the chimney. Its device is slightly different from the chimney system of a home stove. It must ensure long-term heat conservation and the safety of the steam room visitors. Before organizing a chimney in a bath, it is worth learning a few important nuances.
The design of sauna stoves includes 2 types of chimneys:
- Indigenous. They are organized next to the stove, using a special pipe for connection, through which the smoke goes into the main channel. One chimney can be used for 2-3 stoves. The main thing is that its inner diameter has the appropriate parameters, and the pipes from each heating device are located at different heights;
- Packed tube systems are mounted directly on the chimney and led out through the roof. This chimney option is the most common for sauna stoves.
The classification of chimneys at the installation site includes 2 types:
- Outdoor. Most of them are located outdoors and fixed on the wall with a bracket. Not too recommended for a bath, as they cool down quickly, losing precious heat.
- Internal. These are vertical structures with good traction, located inside the building.
According to the material used, chimneys are:
- Brick. A traditional look, characterized by laboriousness of masonry and high requirements for compliance with all parameters. They have a lot of advantages: durability, fire safety, strength, good thermal insulation and heat accumulation. The disadvantages include the roughness and angularity of the inner surface on which soot deposits accumulate;
- A metal chimney is installed faster and is cheaper. It has a perfectly smooth surface, but weaker heat-retaining characteristics;
- Combined version, including 2 parts: the lower one is made of brick, the upper one is made of a modern sandwich pipe. Allows you to organize neat, small passages that are easier to cover with heat-resistant material.
Chimney materials
Before purchasing materials, it is necessary to determine the structural features of the chimney.
Brick system
The structure is made of heat-resistant bricks using a special dry mix or kiln clay. In addition, material may be needed to create the fungus above the pipe.
Metal construction
Before purchasing material for making a metal chimney in a bath, it is necessary to draw up its exact diagram with a detailed location of all corners and turns of the pipe.
You will also need 2 iron sheets with holes corresponding to the pipe diameter. They are fixed on the ceiling of the bathhouse and on the floor of the attic. You will also need heat-resistant material, which will be fixed around the pipe at the point of its exit to the wooden attic.
To create waterproofing around the chimney on the roof, it is necessary to prepare a sealant or a special rubber seal.
Pipe selection: what to look for
When buying iron chimneys, you need to decide on their cross section. Basically, it depends on the power of the stove, but for most sauna options this parameter is 15-20 cm.Do not take too large a diameter, as it will retain heat poorly. And too small - will not create the necessary draft for the extraction of smoke. Whatever it was, the cross-section of the pipe should not be less than the diameter of the outlet pipe of the heating structure.
There are also a number of requirements for the elements of the chimney in the bath:
- The minimum pipe height is 5 m. Neglect of this requirement threatens to deteriorate traction. The exact value is calculated depending on the location of the pipe on the roof. In any case, it should rise at least half a meter above the ridge. The ideal height from the ridge is considered to be 1.5 m, but this is not necessary;
- The minimum thickness of the metal used to create the pipe is 1 mm;
- If it is planned that the chimney system will be equipped with a hot water tank, then it must be reflected in a previously drawn up diagram. It is better if the tank is made of stainless steel.
Safety first
The temperature of the chimney in the bath can rise to critical limits, therefore, the organization of the system must comply with the fire safety requirements:
- The joints of individual parts of the pipe must be strictly sealed;
- The places where the pipe passes through the ceiling are insulated from wooden elements with refractory material (sand, asbestos, expanded clay);
- The exit of the pipe through the roof is treated with waterproofing designed to keep the sheathing from moisture.
Conclusion
The chimney plays an important role in the design of the sauna stove. The health of visitors to the steam room, the safety of the building and everything that is in it depends on its quality. Installing a chimney in a bath must meet all technological requirements, otherwise the consequences can be the most sad.
Consider all the nuances
In the construction of baths, it is wood that is most often used... This is not surprising: it is a warm, environmentally friendly, healthy, but ... also combustible material: under certain conditions, wood can ignite spontaneously at temperatures from 100 ° C.
Reed roof, as in the project Bath under a hood, it requires even more attention.
● According to European standards and safety requirements for the placement of chimneys, the height from the ridge of the reed roof to the chimney outlet of solid fuel equipment must be at least 80 cm! Regardless of the distance to the chimney from the ridge.
● A spark arrester must be installed on the chimney, and the connection of the stove to the chimney must be made with a cleaning pocket.
● Under no circumstances is the stacked version of the chimney permitted. The design of the spark arrester is designed in such a way that the mesh does not clog quickly, and the diameter of the stainless rods and the size of the mesh are designed so that sparks cannot pass by. Installing a regular mesh as a spark arrester can lead to a rapid overgrowth of soot, which is more dangerous for combustible roofs to ignite.
Chimneys for wood-burning stoves combined with a reed roof used in countries with milder climates (in the diagram of the UK standards for chimneys for reed roofs), but at the same time, the chimney without a spark arrestor must rise above the roof at least 180 cm.
Operate the oven correctly
Sauna heaters direct flue gases into the chimney with a maximum operating temperature of 600 ° C. And with improper operation or construction of the stove, the temperature in the chimney can reach 900 ° C. The process of heating a sauna stove often takes place continuously and for a long time. So most often a fire occurs in a sauna attic - and precisely because of the heating of combustible structures by the chimney!
An important safety condition is the observance of the rules for operating the furnaces. Prefabricated oven manufacturers detail these rules in their instructions.
● Avoid excessive draft (hum) in the chimney.
● Regulation is carried out by supplying air to the combustion chamber.
● The quantity and quality of firewood must exactly match the manufacturer's instructions
In case of violation of the rules of the furnace wood gas can burn out in the chimney, overheating the structures of the roof and floors. Particular attention should be paid to this in winter. The relative humidity of the air is low (the likelihood of spontaneous combustion of combustible materials increases), and the temperature difference most of all contributes to the formation of super-thrust.
Choose your pipe wisely
The bathhouse often lacks constant heating... And, for example, for brick pipes "salvo" firing is simply destructive. High-temperature flue gases heat up the system, thermal stresses arise, and cracks appear in the brick chimney due to the temperature difference between the external and internal environment.
The use of steel sandwiches for sauna stoves requires special attention. The maximum operating temperature that stainless steel can withstand without changing the metal structure is 600 ° C. Continuous firing of a furnace with such pipes for more than 4 hours can lead to heat transfer to the enclosing structures.
In addition, not all double-circuit steel chimneys suitable for operating temperatures of 600 ° C - many are designed for a maximum of 400 ° C. Above 400 ° C, stainless steel loses its properties faster and burns out, and it is the insulation layer that burns out, and the thicker it is, the faster.
However, the single-loop steel pipe radiates heat too much and can heat combustible structures to spontaneous combustion at a distance of up to 400 mm. Therefore, the use of a non-insulated chimney in places close to combustible structures is unacceptable.
Double-circuit pipes should be used especially carefully. for sauna stoves in the presence of a room above the steam room with the presence of people. The possibility of touching should be excluded. In such cases, European regulations require the placement of steel sandwiches in fire-resistant ventilated mines.
Fundamentally different materialused in chimney systems for sauna stoves is ceramics. Ceramics for temperatures above 300 ° C must be insulated without fail for uniform heating. At the same time, it is not afraid of prolonged overheating and is even tested for resistance to temperatures up to 1000 ° C.
The safest solution able to withstand temperature loads for a long time, protecting the bath from fire, is a ceramic system with internal ventilation.
In ceilings, the distance from combustible structures should be at least 10 cm to the surface of ceramic systems and 20 cm - to double-circuit steel systems. Regular indoor ventilation will remove excess heat and moisture from the insulation and outer shell.
Our ancestors used to heat the baths exclusively in black. Inside the log house, in the simplest hearth, a fire was made and stones were heated until they were red-hot. They, by dipping into a container, heated the water. There was no chimney, smoke came out through cracks and ajar doors / windows, a thick soot remained on the walls and ceiling. They began to steam when the last embers burned out. Sometimes with some delay, so that carbon monoxide comes out. Now, ovens are widely used for paired procedures, water is supplied to the baths, a full-fledged floor and a dressing room are made, where the firebox door is often located. But most importantly, a chimney for a sauna stove has appeared, which serves to remove smoke. This is a white bath.
Functions and features of the operation of the chimney in the bath
The main purpose of the chimney in the steam room is high-quality and controlled removal of combustion products in order to completely eliminate the accumulation of harmful carbon dioxide and the formation of burning on surfaces. The resulting draft (with air suction into the combustion chamber) maintains a stable process of operation of the heat generator. By manipulating the flows, the user regulates the calorific value of the furnace and the fuel consumption. You can heat such a sauna stove as long as you like, and all this time you can take a steam bath.
Important! The stove pipe gets very hot, so sometimes this energy is used to prepare water by means of tanks integrated into the design.
Features of heat distribution with different methods of connecting the stove to the chimney
The stove in the bath is heated inconsistently. Accordingly, the flue channel cools down completely between sessions, so the chimney parts are exposed to the strongest multiple thermodynamic loads. The second important factor is operating temperature. Unlike boilers and furnaces used for heating, gases heated to 700 degrees or more are removed here. Often, direct-flow ovens are used in the bath, due to the lack of heating shields or water jackets that remove part of the heat, the smoke turns out to be so hot. Therefore, the problem of burning out chimneys (danger of gas contamination and fire) always remains relevant. Chimneys for stoves in a bath are made of high quality materials. If these are factory-made products, they must be approved by the manufacturer for such difficult operating conditions.
Important! The pipes of the sauna stove are passed through the ceilings or outside the building, along the facade. Choosing a street version, which is easier to install, the channel is insulated along the entire length.
What materials are chimneys made of
Brick pipe
Such chimneys are equally suitable for stone and metal stoves. For the main masonry, refractory bricks and a clay-based mortar or a special "kiln mixture" are used. In the upper rows, facing materials and cement mortar are used.
The main elements of a brick chimney
The flue duct is plastered from the inside to close the seams and smooth the planes - soot and condensation will accumulate less, the draft will become better. The pipe configuration itself is no different, there are standard elements:
- riser,
- fluff,
- otter,
- neck,
- head,
- cap (deflector).
The main advantage of this solution is durability and high fire safety. However, a massive stone pipe needs time to warm up for stable thrust.
Important! A brick chimney for metal stoves is not always a good option. It will not work to build it over the heat generator, so the channel is assembled nearby, the masonry is led from the floor (foundation), and then the furnace is connected to it with a horizontal transition.
Metal pipe
Steel chimneys are relatively light, can be installed over a heat source, therefore they are well suited for factory heaters. The cross section is selected depending on the power of the furnace, you need to follow the manufacturer's recommendations or focus on the diameter of the outlet pipe. Most often, chimneys for stoves in a bath require a cross section of 115 mm.
Plumbing pipes made of ordinary ferrous metal can be taken exclusively with a large wall thickness (from 5 mm), but they can still fail at any time (they burn out from high temperatures and rust from strong humidity). Galvanized products also do not shine with durability, since the protective layer very quickly fades away.
Device and options for connecting a sandwich channel
The only worthy option is stainless steel. In principle, you can use a single pipe, insulating it well in the attic and on the street, but a sandwich will show itself better. These are complete chimneys consisting of small sections. The home craftsman can assemble the sandwich channel by himself. Each element consists of two pipes of different cross-sections, between which there is a heat-insulating filling. The line includes: a starting "single-wall" pipe for heat dissipation (sometimes with a water tank), main moldings about 1 meter long, transitions and elbows, pass-through nodes for overlapping and roofing, inserts with gates, top nozzles, deflectors.
When choosing a model for a sauna stove, you need to consider the following points:
- The wall thickness of the inner pipe should be maximum (from 0.8-1 mm),
- The stainless steel grade must be resistant to temperatures around 850 degrees, such as AISI 321 or AISI 439 and 409.
- The optimal thickness of the basalt filling is from 50 mm (ideally 100 mm), and its density is from 120 kg / m 3.
- We give preference to models with an outer tube also made of stainless steel.
Important! The joints of metal pipes are positioned so that they do not fall into the cutting zone and are in plain sight.
The design of a heat-resistant double-circuit pipe for a bath
Ceramic chimneys
Ceramic chimneys withstand heat and are not afraid of moisture. They are a prefabricated multilayer structure in which everything you need is provided: main linear units, inspection elements, containers for collecting and removing condensate (installed at the very bottom), cover plates, tees, ventilation grilles, top mesh nozzles, etc.
Depending on the design, two types of products are distinguished:
- Monolithic, completely ready for masonry, self-supporting blocks with a circular through channel. There are bulkheads (stiffening ribs) between the inner cylindrical element and the outer flat casing; they form chambers that play the role of a heat-insulating air gap and vertical ventilation ducts.
- Modular systems in which the bearing functions are performed by expanded clay concrete blocks, and the smoke is removed through a ceramic pipe located inside such a shaft. The block is placed on a cement-containing mortar, and the pipe from individual sections is collected on a sealant. Mineral wool, like a sleeve, is wrapped around a ceramic pipe.
Kit for making a ceramic chimney
Stoves and ceramic chimneys for baths are connected using a monotube made of heat-resistant stainless steel. It connects to the shaft from the bottom or from the side. The installation scheme is chosen depending on the technical conditions. The relatively low weight of the finished shaft allows for a top-mounted installation, although it is imperative to use support brackets or a brick base vault. If desired (for example, to free up space in the steam room), the root scheme is implemented without any problems - the chimney is taken out into the dressing room or outside. For finishing the chimney, any suitable material (paint, flat stone, tiles) is used, after having sheathed the blocks with cement slabs.
When choosing a stove chimney, do not forget that it will work in extreme conditions. Systems for conventional boilers and fireplaces cannot be used in this case. It is important to know and follow the installation technology, therefore it is advisable to invite experienced craftsmen to assemble the pipe.
Video: do-it-yourself sandwich chimney installation
To the bathhouse, how to equip it, why certain problems arise during its operation - these questions often baffle those who come across them and this is understandable, many of them cannot be solved without professional advice, so let's discuss them together.
The sauna stove smokes, we clean the chimney regularly (almost once a month), but it quickly clogs up, and resinous deposits form on it. How to deal with this?
This is due to an insufficient system for supplying air to the furnace, which entails an insufficient combustion temperature of the wood. Such a problem occurs with stoves with a long burning period: a small firebox cannot form the required temperature and all heavy fractions form an oily coating in the firebox and chimney.
To solve it, you need to lengthen the chimney by 50–70 cm and clean the air supply system to the furnace. If you have a factory-made stove, you need to drill three to four holes with a diameter of 12 mm in the lower edge of the firebox near the blower.
Take dry wood (preferably hardwood, but not birch) and maintain the maximum combustion temperature in the furnace for half an hour. This should be done in rainy weather or in winter, because resinous compounds, when burned out, can form a fiery stream in those places where formations have accumulated (pipe, chimneys, etc.). There are times when a column of flame up to one and a half meters high escapes from the pipe during this procedure.
A heat exchanger for heating water is built into the iron stoves for a bath, can it be used as a heater for a floor heating system, and can a hot water tank be taken out to the chimney?
Of course, such a system can be mounted, but keep in mind that the oven should be 20-25% more powerful than it would be necessary for the volume of your premises. In addition, it will definitely be necessary to provide for a forced air supply system when firing up.
Also keep in mind that if you want to increase the share of heat coming from burning wood for heating the underfloor heating system, this will entail a greater consumption of wood and overheating of the walls of the furnace. If you want to put a tank on the pipe, then this system will interfere with the discharge of gases into the chimney at the time the stove is ignited.
A brick oven for a bath does not heat up well. Tell me, what could be the reason?
To begin with, we want to draw your attention to the fact that a brick oven in a bath requires a longer heating period, but the specific heat of the brick is higher, and it keeps heat longer. Therefore, a bath with a brick stove must be heated for several hours longer than with an iron one.
If you do everything correctly and the stove still heats up badly, then the reason here may be excessively thick walls of the furnace or a direct-flow gas exhaust system.
See how the firebox is arranged in the stove. From the side of the steam room, it should be laid out in a "half brick" (thicker walls do not warm up). Pay attention to how the chimney works. If it is straight-through, then the firewood will "fly into the pipe" almost literally.
The air jet from the firebox must give off part of its heat to the walls of the furnace; for this, passages along the walls of the furnace are structurally laid in cutting the chimney. The smoke temperature at the exit from the firebox reaches 350–400 degrees, and at the exit from the chimney no more than 50–80 degrees (this is the norm). All the heat goes to heating the brick oven. If there are mistakes in the masonry, call the stove-maker.
I can't decide which stove to put in the bath. Some advise an iron, others a brick oven for a bath. Tell me which one is better to choose?
It all depends on how often and how long you will use the sauna. If the trips to the bathhouse are occasional and not long, then the use of an iron stove would be ideal. Its advantage is that it quickly heats up the room, but it also cools down quickly. If you are a connoisseur of a bath and a trip to it lasts for several hours, then in this case a brick bath stove will be an ideal option.
The heat capacity of the brick is high and it is able to give off the accumulated heat for up to 12 hours. In addition, a brick oven can adsorb excess moisture in a room and create a better microclimate for bathing procedures.
The disadvantage of such a sauna stove is a large amount of wood burned, a longer heating period and the size of the stove. The advantages include a more even temperature in the bath, a long period of operation and a microclimate close to natural.
Baths of large sizes are made for a brick stove, for iron stoves - the size of a bath is planned to be smaller. In addition, do not forget that if an iron stove fails, it will be much easier to dismantle and replace it than a brick one.
The iron stove for the bath heats up the wall of the log house very much, what should I do?
To avoid this, it is necessary to overlay the oven with a brick "apron". The apron is laid out in a "half-brick" at a distance of 15–20 cm from the wall of the bath.
In addition, at a distance of 3-5 cm from the wall of the log house, an insulating "sandwich" is attached, which is made of a combination of an insulating mat, a dense surface and a reflective layer.
Here, all air gaps play the role of convection chambers, which force air to circulate and thereby cool the surface, preventing it from overheating and igniting.
The iron stove for the sauna heats up the steam room very quickly, and the water in the tank is barely warm (the tank is mounted on the chimney), why is this happening and what to do?
Most likely, for your steam room you are using an excessively powerful sauna stove with increased heat transfer. That is why the volume of the steam room has time to heat up faster than the water in the tank.
Try reducing the volume of stones in the stove by 1/3, which will reduce the heat output of the stove, or reduce the volume of the hot water tank by one third.
Try also when heating a sauna stove to keep the flame intensity at half of the maximum until the water is heated to the desired temperature. This will make it possible not to overheat the stones and at the same time the water will have time to heat up to 75 degrees.
How to air dry the floor using a brick sauna stove. The fact is that the floor does not have time to dry out after washing and an unpleasant smell arises in the bath.
It is very effective in this case, when laying a brick sauna stove, to mount 3-4 pipes Ø 45-52 mm one row above the furnace, preferably into the chimney. One end should be tightly welded, and the other should be brought out below the level of the wooden flooring. The hot air stream from the pipe will dry out the wood floor.
Attention! The pipes should not be in the firebox, in this case they will glow and there is a high probability of getting burned from the hot air flow.
We hope that our tips will help you solve the arising issues related to the stove in the bath, and, having solved them, you will be able to steam with pleasure without being distracted by any problems.
In this article I will present my own vision of the topic in the title.
To begin with, let us briefly recall what temperature and humidity conditions are typical for a Russian bath. For those who want to get acquainted in more detail with all possible existing modes of taking bath procedures and choose the most preferable ones for themselves, I recommend taking a look .
So, a steam Russian bath is characterized by air heating temperatures in the steam room up to T \u003d 45-65 ° C and relative humidity φ \u003d 50-90%. The absolute humidity of the air in the steam room of the Russian bath varies within ρ \u003d 60-150 g / m³.
At the same time, the temperature and humidity conditions typical for a dry-air sauna lie in the temperature range Т \u003d 90-130ºC and relative humidity φ \u003d 2-10%. In this case, the absolute air humidity is ρ \u003d 8-16 g / m³.
From the above figures, it can be seen that if the air temperatures in the baths of these types differ by a factor of two, then the amount of water vapor in the air differs by an order of magnitude.
In a Russian steam bath, a person is heated by a high-humidity air environment, while in a dry-air sauna, a person is heated by dry air.
Washing a person in a steam bath takes place in steam with a broom (by settling condensate of water vapor from the air on the surface of the body with a bath broom and using a bath broom as a washcloth).
Washing in the steam room of a dry-air sauna is not provided initially. In such a steam room you can only warm yourself up with dry air. Body washing is carried out, as a rule, under a regular shower outside the steam room. The use of a broom in a dry-air steam room is more of a ritual rather than a functional one.
Thus, the purpose of the Russian steam bath is to create conditions in a steam room: Т \u003d 45-65 ° С, φ \u003d 50-90%, ρ \u003d 60-150 g / m³.
In addition, the heat content of humid air in the steam room of a Russian bath, which makes it possible to obtain , should be equal to I \u003d 165-200 kJ / kg d.w. - at the stage of preliminary heating of the organism and I \u003d 200-270 kJ / kg d.w. - at the stage of steaming with brooms.
The question arises, with the help of which furnace (metal or brick) it is easiest to achieve these modes.
First, consider the features of metal sauna stoves.
Metal furnaces are characterized by a temperature of their outer surface, as a rule, exceeding 120 ° C... This is observed even in cases where the metal stove has external protective metal screens that cover the outside of the firebox, which heats up to much higher temperatures. (T\u003e 300 ° C). The temperature of the part of the chimney located in the steam room and in direct contact with the stove practically does not differ from the temperature of a red-hot firebox.
A metal furnace with a relatively small external dimensions (with the area of \u200b\u200bthe side surfaces from 1 to 2m²), is a source of powerful infrared radiation. The values \u200b\u200bof radiant heat fluxes (depending on the model and dimensions of the furnace) from the walls of such furnaces unprotected by heat shields can reach very large values \u200b\u200bof the order of 10-30 kW / m². For comparison, the critical heat fluxes that a person can withstand with his bare skin for a few seconds are fluxes
Metal furnaces have low heat capacity and low response time. They heat up very quickly when kindling, but also quickly cool down when the process of burning wood in the firebox stops.
Metal stoves, in most cases, are not able to dry the bath after the end of the bath procedures.
Convection air currents created by metal stoves, passing between the outer protective screen of the stove and the metal walls of the firebox, very quickly heat the air in the steam room to temperatures inherent in dry-air saunas (T \u003d 90-130 ° C). In addition, as a rule, in metal stoves, the heater is located outside the stove. This arrangement of stones also creates convective air currents, which contribute to the overheating of the steam room.
Due to the existence in a steam room with a metal oven and, as a rule, uneven heating of the elements of the enclosing structures of the steam room (ceiling, walls, floor) in such conditions it is very difficult to keep the required air humidity at the required level for at least 5-8 minutes, during which the broom steaming mode occurs.
If, nevertheless, at the established air temperature in the steam room, typical for dry-air sauna modes (T\u003e 90 ° C), evaporate the volume of water on the stove, which will create absolute humidity in the steam room ρ\u003e 50g / m², it will be impossible to bathe in these conditions. And that's why.
Under these conditions, moisture will begin to condense on a person with a temperature equal to the air temperature, that is, with T\u003e 90 ° C.Agree, the situation is not pleasant.
And this will happen for the following reason. A human as a biological species cannot heat up to a temperature of more than 40 ° C... Sometimes, however, after preliminary gradual heating, you can raise the temperature of the human skin to a temperature ~ 50 ° C... But this does not change the essence of the picture being drawn.
Absolute air humidity equal 50g / m³ at a temperature 40 ° C will give 100% relative humidity. In other words, the temperature 40 ° Cis the dew point for humidity 50g / m³. Under these conditions, from the air to any object with a surface temperature equal to 40 ° C, dew will begin to fall with a temperature equal to the air temperature.
And what is our temperature in the steam room?
Correctly. More 90 ° C.
And here we are in the situation: "Did you order the boiling water?"
What is it? !!!
As for me, the BURST.
And lastly, regarding metal stoves.
The external placement of the stove on top of the stove does not allow them to be heated to the temperatures required to obtain "light steam". These temperatures are stones heating temperatures .
The desire to achieve the specified temperatures of the masonry inevitably leads to overheating of the steam room to temperatures exceeding the required range (T \u003d 46-65 ° C).
The desire to prevent overheating of the steam room leads to underheating of stones.
And so, and so not great!
Now let's see what the brick ovens give us in the steam room.
Unlike metal ovens, brick ovens are inertial in terms of their own heating and heating of the steam room, as well as heat capacity.
Brick ovens take a long time to heat up, but also give off the heat accumulated in the brickwork for a long time.
In a properly folded bath brick oven, the wall temperature rarely exceeds 90 ° C... Accordingly, a brick sauna stove during the heating period with its outer walls rarely can heat the steam room air to temperatures exceeding 60 ° C, and, therefore, overheat the steam room.
In correctly folded bath brick ovens, the heating temperature of the oven walls is uniform in height, which gives a more uniform heating of the steam room from floor to ceiling.
In the case of placing a stone bookmark inside a brick oven, again, the possibility of overheating the steam room above the temperatures typical of the modes of a steam Russian bath is excluded (T \u003d 46-65 ° C).
A brick oven with a stone insert inside it allows stones to be heated to higher temperatures than in metal ovens. So, for example, the temperature of stones in brick kilns of batch operation I. V. Kuznetsova, reaches 600-700 ° C... In some brick ovens I. V. Kuznetsova continuous operation (in particular, in the RusSauna furnace), when the stones are placed inside a special metal box placed inside the furnace, the temperature of the stone setting can reach 400-450 ° C.
From stones heated to such temperatures, it is easy to obtain superheated steam with a temperature above 100 ° C... In such a vapor, there is no water in the form of individual drops or aerosols (with a water particle size less than 100 μm). Water evaporated on stones with such a temperature is water gas, that is, water split into a molecular state.
From the water vapor obtained under these conditions.
It should be noted that a very important fact is that the main task of the oven in the Russian bath is to heat the brickwork to the high temperatures indicated above without overheating the steam room.
The easiest way to cope with this task is brick ovens with an internal arrangement of a stone fill.
Brick stoves, in which the heated stones are located outside, located in a metal oven open on top, as a rule, underheat the stones, and also overheat the steam room due to the creation of convective flows of air masses of the steam room above the stove.
Attempts to prevent the steam room from overheating when stoking such brick ovens inevitably lead to subheating of the stones. Stones in a metal box open on top do not heat evenly (more from below, less from above), to lower temperatures (rarely exceeding 200 ° C) and accumulate less heat.
This is due to the fact that stones placed in an open oven are heated mainly due to convection heated air currents inside the metal box, as well as conductiveheat transfer in places of contact of stones with each other.
As a result, the energy stored by the stones after several surrenders of water on them is not enough to create superheated steam. The stones cool down faster, and the water evaporated on them is a vapor-air mixture, in which water is not only in a gaseous (molecular) state, but also in the form of individual drops and aerosol.
Such a vapor-air mixture cannot give " light steam ".
In the case when a stone bookmark is inside stoves directly above the firebox, heating of stones occurs mainly due to radiant heat the flame of burning wood and emitted by the heated inner surfaces of the brickwork of the firebox.
Due to the fact that radiant heat transfer (already starting from temperatures T\u003e 200 ° C) exceeds the convective one (see Table 1), therefore the stones in such conditions are heated to higher temperatures, and the stone fill accumulates more heat.
Table 1.
| Furnace temperature , ºС | ||||||||
| Convection heat transfer, kW / m² | ||||||||
| Radiation heat transfer, kW / m² |
From heated to temperatures 500-700 ° C overheated steam that does not contain water droplets is easier to obtain. Consequently, it is easier to get "light steam"
And further. A massive brick oven cools down for a long time and the heat stored in its array is quite enough to dry the bath after it has been taken. This is especially critical for baths with massive steam room walls, capable of accumulating moisture inside themselves when large amounts of water evaporate on the stove.
The organization of properly organized preservative ventilation of the steam room, in conjunction with a long-cooling heat-intensive massive brick oven, copes without problems with drying the bath after its adoption.
Let's summarize.
1) We examined the features inherent in metal and brick stoves used in the bath, their strengths and weaknesses.
2) The strengths of metal ovens are:
- shorter periods of heating the steam room to the temperatures desired by the user;
- less firewood consumption, compared to brick ovens;
- lower cost compared to a brick oven.
The weaknesses of metal ovens are:
- the complexity of obtaining the modes of a Russian steam bath in a steam room with a metal oven;
- with a metal stove it is easy to underheat the heater and overheat the steam room;
- it is difficult to dry the bath after the end of the steam bath procedures.
In other words, metal stoves are better suited for creating dry air saunas (with little water use) than a Russian steam bath (using large volumes of water).
3) They showed that the regimes of a steam Russian bath are much easier to obtain in a steam room with a massive brick stove, in which the stove is placed inside the stove.
The strengths of brick ovens are:
- the ease of creating both steam modes of a Russian bath and modes of a dry-air sauna, provided that the stone bookmark is heated inside the furnace;
- if desired, the possibility of taking bath procedures within a few days after heating the stove;
- ease of drying the bath after taking steam and water procedures.
The weaknesses of brick ovens are:
- b ABOUTlonger cooking times for the bath in comparison with the use of metal ovens for these purposes;
- b ABOUTthe greatest consumption of firewood;
- b ABOUTthe higher cost of building a brick sauna stove compared to the cost of a metal stove;
- in the absence of knowledge and skills in laying bath brick stoves, turning to the services of a third-party stove-maker with obtaining an unwarranted result of laying a good bath stove.
That's all for now.
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Until next time!