Stoves-heaters for the Russian bath

An individual sauna without a good stove-heater loses its direct functional purpose and its steam room turns into an ordinary washing and shower room. A heater-stove that heats the air in the steam room to 60-80 ° C, accumulates in itself and the stones a large amount of thermal energy, converting the water into scalding steam – this is the basis, the heart of a real Russian bath. Therefore, a variety of requirements are imposed on the heater-heater, which it must meet as much as possible: – take up little space; – have a sufficiently large heating capacity; – quickly warm up the steam room; – to warm the volume of water sufficient for the whole family (10-15 liters per person); – keep accumulated heat for a long time.

These conflicting requirements show that the choice of stove for your bath must be taken very seriously. Its design, operational parameters must first of all be chosen, taking into account the size of the steam room. In a small family bath with sizes from 2×2 to 3×3 m, metal, brick-lined stoves are usually used. The installation of such a furnace can be done without a foundation, but for this, in the place of its location, it is necessary to first strengthen the floor with thickened planks, or make an additional columnar foundation for a lag of a larger section. To evenly distribute the load from the stove to the floor, its base should rest on a metal sheet (2-3 mm), under which asbestos cardboard is laid, which will reliably protect the floor from possible fire.

In fig. 1 shows a small closed metal oven with a 60-70 liter hot water tank on top. The furnace body with dimensions 600x700x1500 mm is welded from steel sheet 5 mm thick. As can be seen from the section of the stove, it consists of three zones: the lower one is a firebox with a blower, the middle one is a heater with a 200×250 mm window for steam outlet, and the upper one is a water tank that is heated by a chimney. The bottom of the tank is welded from thickened sheet steel for reliability.

Fig. 1. Metal stove-heater with a hot water tank: 1 – external brickwork; 2 – furnace body; 3 – internal brickwork; 4 – wire clips; 5 – hot water tank; 6 – chimney; 7 – stones; 8 – hatch for steam outlet; 9 – lattice; 10 – support bar; 11 – firebox door; 12 – blower door; 13 – metal support sheet

This stove is quite heat-consuming, since its inner and outer parts are lined with red bricks. It is strictly forbidden to use white sand-lime brick for interior and exterior cladding. It is advisable to use refractory bricks for interior cladding. The internal cavity of the furnace is lined with bricks on the edge from the grate of the furnace to the bottom of the tank, and from the outside the furnace is laid out in half a brick on three sides, except for the front one. The brickwork is fixed with special wire clips with a diameter of 3 mm, which are welded along the markings to the furnace body. In the middle zone, stones are laid on a lattice of reinforcing bars with a diameter of 28-30 mm, which is freely lying on strong support strips (channel, rail, etc.). To speed up the heating of water in the tank and stones on the grate, the tank and the steam outlet are closed with a lid and a galvanized sheet damper.

A stove of this design is very convenient for a family bath, it is small in size and can be made without much difficulty. Such metal stoves do not have a very high heat capacity, therefore the necessary thermal effect is achieved by the fact that firewood is constantly burning in its firebox, which ensures the maintenance of the required thermal regime in the steam room. These are stoves of constant heating, that is, such a stove must be heated continuously, while bath procedures are being taken in the steam room. However, the heat capacity of a continuous heating furnace can be substantially increased by internal and external brick cladding, similar to the furnace shown in Fig. 1. A small metal stove, especially a brick-faced one, has some advantages that attract the owner of the bath: it does not require significant financial costs, heats up a steam room with a volume of 8-10 m3 in just 1.5-2 hours in winter, quickly heats stones up to 300 -400 ° С and water to a boil, there is no risk of carbon monoxide poisoning.

Constant heating stoves have a closed stove (Fig. 1) or open, when stones are stacked in a heap above the firebox and there is no ceiling or ceiling of the stove above them (Fig. 2). For a family sauna, in which several people steam on the same day, an open heater is preferable, as it warms up the steam room much faster. In order to keep the open heater hot at all times, cover the stones with a galvanized sheet cover after each batch of steam. In fig. 2 shows a stove with an open stove, in which there is also a water-heating tank with a capacity of 50-60 liters. It has only an external brick lining, and the rest of its design is similar to the first version of the furnace (Fig. 1).

Fig. 2. Metal stove with an open heater: 1 – brickwork; 2 – furnace body; 3 – clips; 4 – screen cover of the heater; 5 – chimney; 6 – water heating tank; 7 – stones; 8 – lattice; 9 – support bar; 10 – firebox door; 11 – blower door; 12 – support sheet

The chimney in metal furnaces is made of 1-1.5 mm tin, the lower branch pipe 1.5 m long, installed in the furnace, it is desirable to make from a water pipe with a diameter of 100-150 mm. A flange connection with a damper is arranged on this branch pipe. Properly selected high-quality stones play an important role for the heater to work well. Cobblestones must be selected heavy, strong, without cracks. They should be rounded, smooth and of various sizes (50-150 mm). The stones are laid on the lattice as follows: the largest stones are laid down so that they do not completely cover the cracks in the lattice, then stones of a slightly smaller size are laid, and the smallest ones should be at the top. The total weight of stones depends on the size of the steam room; in a metal stove for a small family bath, the weight of stones is 80-100 kg. A sufficient amount of stones accumulates a lot of thermal energy, while the upper stones must be heated to 300-350 ° C, then the water splashed on the stones immediately turns into dry hot steam. On well-heated stones, water should instantly evaporate with a kind of crackle. Stones in small ovens of constant heating are gradually covered with soot, so they must be periodically cleaned: after 3-4 months. Then, over time, the stones become covered with cracks, they begin to crumble, and they are replaced after 2-3 years.

For the small stove shown in fig. 1, 2, the chimney is usually used asbestos-cement or metal. The author proposes a combined option, in which the lower part of the chimney is metal, and the upper part is asbestos-cement.

Fig. 3. Combined chimney device: 1 – heater stove; 2 – sliding support; 3 – metal pipe; 4 – asbestos pipe; 5 – support ring; 6 – plug; 7 – plug clamp; 8 – support rack

This design is more preferable, since there is no direct contact of the asbestos-cement pipe with the furnace and there is no direct exposure to a very high temperature. This eliminates the risk of sudden cracking of the asbestos-cement pipe and all the unpleasant consequences of its destruction (fire, injury, pipe replacement, etc.). The combined chimney is less fire hazardous in comparison with a completely metal one and for its upper asbestos-cement part, thermal insulation is performed in the places of passage through the ceiling and roof of the bath, which is not as laborious and complicated as for a metal.

The chimney is usually taken out 0.4-0.6 m above the ridge of the bath roof. A protective cap from precipitation is installed on the top of the pipe. The lower blind end of the chimney is closed with a tight tin plug; it is used to clean the pipe from soot and drain condensate. The entire structure of the combined chimney is supported by a sliding support located on its metal part, that is, the pipe lies freely on the support part, moving with thermal expansion.

For an individual family bath of large sizes, the installation of a heat-intensive brick oven of periodic action is most acceptable. Massive brick stove-stove of periodic action is of two types: with an open stove or with a closed one. The brick stove with an open stove is an old stove used in the Russian smoke sauna..

Fig. 4. Brick stove with an open stove: 1 – stove body; 2 – stones; 3 – water tank; 4 – firebox door; 5 – blower door

In such a furnace, stones are placed in a heap above the firebox, and hot smoke, passing through the stones, heats them up to 400-450 ° C. At the same time, the heat of the furnace does not immediately fly out through the chimney, but passes through the stones and heats the entire room, especially its upper part. This oven heats up the steam room very quickly and after 1.5-2 hours you can take bath procedures. If the stove has a large volume of stones (250-300 kg), then several families can take turns in the bath. A 60-80 liter water tank is installed in the oven in front of the stove, which is closed with a lid to reduce evaporation. It is advisable to heat a stove with an open stove with dry birch, aspen or oak wood, which give little soot. Bitumen, roofing felt, and plastic must not be thrown into the furnace.

In a comfortable Russian bathhouse, brick ovens with a closed stove are used (Fig. 5). These are rather heat-consuming furnaces, as they have massive brickwork and a large volume of stones (200-250 kg). Such a stove is good in that after the end of the furnace, it accumulates a large amount of heat, which is enough for long-term use of the bathhouse by a large family.

Fig. five. Brick stove with a closed heater and side placement of the water tank: 1 – hot water tank; 2 – oven; 3 – chimney; 4 – stones; 5 – heater cover; 6 – hole for water supply; 7 – metal vault; 8 – screen; 9 – grate; 10 – firebox door; 11 – blower door

The mass of stones for a stove can be calculated based on the fact that 1 m3 of a steam room requires 30-40 kg of stones. Thus, a small steam room with a volume of 8-10 m3 requires at least 250-300 kg of stones. But it must be emphasized that this calculation is only suitable for batch-type brick ovens. The mass of stones for constant heating stoves is much less (80-150 kg), since the heat of the stones is supported by burning wood. Brick stoves-heaters of the type designed by A. Suzdaltsev, A.F. Filichko and others, which are quite complex and require a qualified stove-maker. In order to lay down a reliable, heat-intensive and at the same time simple brick stove with a closed stove with his own hands, the author offers his own version of the design, shown in Fig. 5, using for the furnace roof a piece of a metal pipe cut along a length of 300-400 mm and a length of 500 mm. Supporting steel sheets with a thickness of 5-6 mm are welded to the pipe cut along the length. With their help, a piece of pipe is laid in the brickwork of the furnace. For the tightness of the arch, the ends of the pipe are also scalded with a metal sheet with adjoining brickwork. From the side of the chimney, a metal sheet is welded to the tubular vault – a screen that slightly delays the exit of hot air into the chimney. A 50x37x25 cm water-heating tank with a capacity of 40-45 liters is embedded in the side wall of the furnace. The tank is made of sheet steel 5-10 mm thick; the side adjacent to the firebox is welded from a 10 mm sheet. On the inside of the side wall of the furnace, a metal section of the chimney is installed (Fig. 5), which is equipped with a round damper. The chimney is fixed in the brickwork with wire clamps, and at the bottom it rests with its cut end on a metal tank. The upper part of the furnace developed by the author is a heater, where stones with a total weight of 150-200 kg are placed. The stove is covered from above with a galvanized sheet cover. To release steam, it is removed. Water is supplied to the stones through a side hole 200×250 mm. This stove can be operated both periodically and continuously, that is, it can be heated during bath procedures. In this case, the heater is filled with a smaller mass of stones (100-150 kg).

For the calculation shown in Fig. 5 ovens required:

• Ordinary brick – 210 pieces.
• Clay – 0.1 m3
• Sand – 0.15 m3
• Reinforcing bar 25-30 mm for grate – 2.5 m
• Furnace door 250×210 mm – 1 piece.
• Blowing door 140×130 mm – 1 piece.
• Metal pipe 100-150 mm – 1.2 m
• Asbestos-cement pipe 80-130 mm – 2.5 m
• Water and gas pipe 300-400 mm – 0.5 m
• Steel sheet 5-10 mm thick – 1.0 m2
• Galvanized sheet metal 1 mm – 1.0 m2

In fig. 6 shows the combined stove-heater for small steam rooms developed by the author.

Fig. 6. Brick stove with a metal stove and a side location of the water tank: 1 – tank support; 2 – water tank; 3 – chimney; 4 – hatch for watering stones; 5 – heater cover; 6 – wire clips; 7 – stones; 8 – heater grill; 9 – stands for the stove pedestal; 10 – grate; 11 – firebox door; 12 – blower door

The compact stove is made of bricks, the body of the stove is welded from 8-10 mm sheet steel. The heater rests on a pedestal and stands made of 50×50 corner pieces. The grates of the heater and stove are made of 24 mm reinforcing steel. The body of the stove measuring 530x510x500 mm is lined with bricks on the edge, fixed with wire clips. This stove has a side-mounted tank with a capacity of 50 liters, in which the water is heated by a metal chimney. The tank is made of a 400 mm metal tube and is supported by a sliding support. The stones are heated both from the chimney and by the ascending currents of hot air. The stove body has a hatch through which water is splashed to obtain steam, after removing the cover from the top of the stove. For stronger heating of the stones, the hatch is also closed with a lid. This stove can operate both in constant heating mode (winter) and in periodic heating mode (summer), which is very convenient for a family with a small individual sauna.