Room stove
A room stove is a stove that is used to heat a room . In contrast to central heating and its radiators , the heat is generated directly in the room.
There are different types:
To be heated with wood or coal:
- open fireplace
- Cannon furnace
- Warm air wood stove .
To be heated with other materials:
- Oil stove
- Gas oven
- electric night storage heater .
construction
Room stoves are of very different construction, but should always enable the most complete possible combustion of the fuel (in incinerators) as well as optimal transfer of heat to the furnace material and from this to the room air. In the case of incinerators, the smoke flues of the furnace must be easy to clean. In all constructions one tries to achieve a suitable circulation of the room air and a certain ventilation .
The following general principles apply to the construction of the furnace: Room stoves are built with and without a grate and the furnace gases are passed through ducts, on the walls of which they give off their heat to a certain extent, and finally into the chimney . When the fire is out, the air flow through the hot stove stops and much heat is uselessly carried on. A flue gas flap is therefore installed in the pipe leading to the chimney and an airtight furnace door that prevents air from entering the furnace, in order to prevent the carbon monoxide that forms in the furnace if the coal is incomplete if the flue gas flap is closed too early .
Depending on whether the stove is heated from the room or from outside, a distinction is made between wind stoves (originally stoves whose fire was intensified by drafts by means of draft holes) and neck stoves, of which the former are the most common. The importance ascribed to them as a ventilation device is by the way not nearly as great as is often assumed (cf. heating and ventilation).
Iron or clay are used as material for the construction of room stoves , the latter more in the north and east and where a room is to be kept at the same temperature all the time, iron more in the west and south and in rooms that need to be heated quickly for temporary stays.
The differences between iron and clay ovens result from the physical nature of the materials. The thermal conductivity of iron is around 33 times greater than that of clay, as a result of which the iron stove heats up faster and releases the heat it has absorbed into the room air more quickly than the clay stove, whose thicker walls also present a further obstacle to heat transfer . In contrast, the specific heat of clay is greater than that of iron, so that an equal weight of clay heated to the same temperature can heat a much larger volume of air to a certain temperature than iron. From this it is easy to deduce the different uses of both materials, the choice of fuels and the treatment of the fire. A moderate fire is maintained in the iron furnace, while the clay furnace is heated up once and then closed.
Iron stoves have the disadvantage that they can easily become too hot on the outside wall and then become annoying and unhealthy due to very strong heat radiation. With overheating that occurs easily, the air becomes relatively dry (which is less noticeable with tiled stoves, because they are much less likely to reach a temperature that is too high), and water vessels must therefore be installed to ensure the necessary moisture content in the air in an emergency. When the iron stove glows, the dust brought in by the air flow burns and foul-smelling substances develop which irritate the respiratory organs .
On the other hand, most of the deficiencies of iron stoves can be eliminated by means of appropriate construction, and the latest forms of these should be preferable to tiled stoves in economic and hygienic terms. The installation and operation of the tiled stove are more expensive than the iron stove, although in general the yield of the calorific value of the fuel depends more on the way the stove is operated than on its construction. Usually 20–30, in the best case 40 percent, and often only 15–20 percent of the theoretical heating effect is achieved.
Soapstone storage stoves , which can have an efficiency of up to 88%, are an exception . Compared to normal firebrick, the thermal conductivity of soapstone is 6 to 7 times better, the specific weight is around twice as high and the specific heat is around 15% higher. It should be noted here that many commercially sold soapstone stoves are only clad with soapstone on the outside, while internally they are identical to other stoves, whereas the combustion chamber of a real soapstone stove is made of the eponymous material.
Types
Clay ovens
The types of clay ovens are the Russian and the Swedish. The former is designed for strong wood-burning and contains 4–12 vertical, burnt-stone, closely spaced trains , the last of which is directed downwards; the heating opening is outside the room.
Swedish stove
The Swedish stove forms a very tall cylinder in which five channels are arranged in such a way that the cylindrical space is initially divided into three parts by two parallel vertical walls, the two lateral parts of which are vertically bisected by a weak wall, during the middle part contains the firebox. The combustion gases rise up here, are distributed in two side channels to the right and left, go down in these and rise again in the side channels next to them, to unite above the middle channel and to escape through a smoke pipe under the ceiling of the furnace. The heating opening is usually in the room.
Feilnerscher furnace
In the case of the Feilner stove, an iron fire box stands free in the stove and allows air to circulate between its wall and the tile wall. The combustion gases escape through a round hole in the cover plate of the box and snake through the furnace in horizontal lines. This stove heats up very quickly, as the cold room air enters below, heats up strongly on the wall of the fire box and exits again about the fourth part of the height of the stove. The entire upper part of the stove, on the other hand, ensures sustainable heating. A furnace of this kind is the Großmannsche in the form given by Romberg and Mehlmann.
The heating and ash door are recessed in the niche of the stove foot, so that the base cornice between the upper and lower body is completely isolated from the combustion door; the heating box, made of fire bricks and vaulted with them, is also isolated from the tile walls by leaving a narrow layer of air on the heating door. In addition, the stove is divided into three parts: In the middle room, enclosed by a brick layer, in which the fire enters through a slot in the vault, there are horizontal lines at the level of the entire stove, and two standing lines in each of the two side parts Trains.
In order to be able to bring about a strong ventilation by means of the oven, two clay pipes are guided in the space between the oven and the wall, which is closed and because of its location is very heated in the middle part of the oven. The air is heated so much that it rises vigorously, and while one pipe is now connected to the air in the open air by means of a ventilation duct and opens into the room above the furnace ceiling, the other pipe is below through the cavity below the The grate of the furnace is carried out and ends at the foot of the furnace, closed by a grille, into the room, while it is led into a flue above.
The first pipe always brings fresh air into the room, and the second one sucks the stale air from the floor of the room and leads it outside. A slide device also allows the air to communicate between the two tubes , and it depends on the position of this slide device whether the ventilatory effect of the stove is to be used or whether the room is to be heated by rapid circulation.
Iron stoves
The iron stove of the oldest and simplest construction (column stove, cannon, barracks stove, deck or hermitage stove) has the main defect that it requires constant and attentive operation to keep the fire burning, because the heat source almost simultaneously with the extinguishing of the The fire has dried up.
Filling furnace
This deficiency is eliminated by the iron filling furnace (bulk furnace, regulating furnace), which enables the furnace to be continuously fed with fuel and consequently evenly heated. The Henschel filling furnace for coke, brown and hard coals consists of a cast-iron jacket with a movable cover and a hollow cylinder, also with a removable cover, that is slipped into this jacket. At the bottom, the inside of the cylinder communicates with the annular cavity closed by the jacket, and the base of this cavity is the grate. To cheer up, a light fire is lit on the latter, the cylinder is filled with fuel and the two lids are put on. The fuel then gradually sinks down and gives a steady fire, the combustion gases rise between the jacket and cylinder and escape under the cover into the stove pipe. The one-time filling lasts for 24 hours to a week, depending on the size of the oven.
Meidingerscher filling furnace
An adjustable door allows the fire to be regulated. The Meidinger filling oven represents a significant advance, and thanks to its simplicity in shape and handling, as well as its practicality and cheapness, it has quickly become widely used. It consists of a cast iron filling cylinder with a base and a double sheet metal jacket. The filling cylinder consists of a lower ring with a sloping neck that is closed by a grinded door, one to four central rings and the upper ring with a smoke tube attachment and lid. There is no rust.
The door can be folded up to empty the ash and moved sideways to regulate the pull. Above the neck in the filling cylinder lies a sickle-shaped plate which forces the air flowing in through the neck to penetrate into the center of the fuel and at the same time prevents the fuel from falling into the neck. The inner jacket protects the outside from the radiant heat of the cylinder. The base and cover are perforated so that the cold air can flow in on the floor and the heated air can flow out above. To ignite the cylinder, use a funnel to fill the cylinder with pieces of coal or coke the size of a nut up to about 20 cm below the smoke pipe, place about 0.5 kg of split wood on it, ignite it, throw a handful of coke or coal over it and close it Cover. After 1–2 hours, the ignition has reached the bottom, and the combustion now only takes place below, while the fuel slowly sinks.
If you use coke you can refill it as you like and keep the fire going for weeks. The ashes are removed through the neck every morning. The shaft furnace in Kaiserslautern also stores a large amount of fuel, allows the use of any fuel and must be refilled at any time.
A cylinder B made up of several rings forms the core of the heater; the obliquely rising long hopper c is attached to the side of the lower ring, while a movable grate gh forms the border against the ash drop box A. The furnace is regulated through the ash trap door a, a flattened flap door that, like the Meidinger stove, can be moved sideways. In addition, however, the regulation can also take place from the room through door b. The quadrangular filling chute contains triangular channels in its upper corners, which reach down to the level of the fuel and lead fresh air into the combustion chamber to facilitate the combustion process. The closed hopper door leaves the entrance of these channels open. The furnace has a jacket and at the same time has a ventilating effect through connection with the channel s', but after this channel is closed and after s is opened only by air circulation.
Palatinate oven
The Palatinate furnace of the Kaiserslautern ironworks is designed on the principle of the shaft furnace for operation in the room. It has two filling necks (shafts), which make it suitable for both temporary and continuous heating. You light a light fire on the grate and pour any kind of fuel through the lower shaft if the stove is only to work for a short time. If, on the other hand, you want to keep the fire going for a long time, you pour nut-sized coke through the upper shaft and leave the middle shaft, which is provided with channels in the corners as in the shaft furnace, closed. Here, too, regulation is carried out by moving the sanded ash trap door, which, however, still has a central hole through which the grate can be shaken using a hook to remove the ash. A jacket allows the stove to be used for ventilation, and the stove can easily be fitted with a simple attachment that makes it suitable for heating two neighboring rooms at the same time.
Lönholdtsch oven
From the American ovens for continuous operation, the Lönholdt oven developed, which represents a significant enrichment of local heating. It is designed as a jacket furnace and consists of an inner heating cylinder a with filling shaft b, basket and shaking grate cd, puffs ee 'and out of the base f, around which a jacket is offset eccentrically so that the furnace has a regular, circular shape. The fire cylinder is provided with ribs to increase the heating surface and the heating effect. The fuel is poured into the furnace feed chute through opening g and is heated so strongly here that flammable vapors and gases develop which come into intimate contact with the glowing fuel that closes off the chute and burns completely.
The grate cage c is placed as close to the floor as possible, the ash trap h under the circulation base in order to prevent the flue gases from being drawn down too much, which is disadvantageous in the case of weak chimneys, and to heat the base as much as possible for the purpose of powerful underfloor heating. The combustion air flows through openings i located in the ash trap door and provided with regulating locks under the hot base to the grate and thus reaches the fuel in a preheated state. In order to achieve complete combustion, air is also introduced into the embers in a horizontal direction through the adjustable and closable opening k directly under the fire door l.
To extract air from the room and to regulate the combustion intensity, there is a duct m above the heating cylinder a, which opens into the room at the front and into the chimney at the back and is heated partly by the ceiling of the fire cylinder and partly by the fire gases flowing through the duct. The room air is drawn through a nozzle n inserted in the front part of this duct into the duct and through this into the chimney. A mica washer o is attached to the inside of the nozzle in such a way that it rises and falls depending on the pulling force of the chimney and therefore automatically regulates the air extraction from the room. In addition, the channel can be closed by the slide p. The stoves are provided with ventilation and room plinths for introducing clean outside air through ducts under the floor q or in the corridor wall r and for circulating the room air.
The air enters the heated base of the stove close to the floor and leaves it, rising between the heating cylinder and the jacket, through the openings s in the upper part of the jacket, after it has been provided with moisture from a water evaporation vessel w. If the stove is to be used to heat several contiguous rooms, some sections of the perforated grille are removed and sheet metal ducts, which can be closed with throttle valves , are led from the openings thus formed to the adjoining rooms to be heated. The operation of the stove is limited to refilling the charcoal into the filling chute, emptying the ash pan every 24 hours and regulating the combustion process by opening and closing the lock in the ash trap door.
history
Orders from Count Palatine Karl IV. From 1772 also served to prevent a fire in connection with domestic fireplaces. According to the simultaneous building regulations, no more wooden chimneys were allowed to be erected, no more wooden hoses were allowed to be installed, which had to lead the smoke from the fireplace to the fireplace, just as it was forbidden to lead stovepipes out of the window.
See also
Web links
Individual evidence
- ↑ Jörg Mildenberger: Anton Trutmanns Pharmacopoeia , Part II: Dictionary, Würzburg 1997 (= Würzburg medical-historical research, 56), V, p. 2304
- ↑ The Truth About Soapstone. In: sueka.de. July 22, 2004, accessed November 29, 2019 .
- ↑ a b Properties of soapstone - Thermo Stone. In: thermo-stone.de. Retrieved November 29, 2019 .
- ↑ Why soapstone? The special properties for heat storage ( Memento from October 13, 2016 in the Internet Archive )
- ^ Franz-Josef Sehr : The fire extinguishing system in Obertiefenbach from earlier times . In: Yearbook for the Limburg-Weilburg district 1994 . The district committee of the Limburg-Weilburg district, Limburg-Weilburg 1993, p. 151-153 .