Dey underlying the bell furnace, has been developed and implemented the first Russian professor, founder of the national school of Thermal Engineering Vladimir E. Groom Grzhimailo. Currently, his work in terms of improving the design of existing and development of new projects of brick kilns, worthily continues and develops Igor Kuznetsov.
The principle of moving gases in the bell furnaces
Figure it can be in the simplest example. To a beaker turned upside down, from the bottom stream is fed smoke. It rises to the bottoms and then cools, flows along the walls of the glass.
That is, there is free movement of gases under the existing laws of physics. That this is the fundamental difference between the furnaces of this type from other structures, where the gases are forced to move, due to the organization of traction.
The hood becomes a kind of trap hot gases. Cold as heavier, move down. Turbulence occurs conducive to a more complete perception of heat-walled hood.
In embodiments, modified Kuznetsov, thanks to the use of the principle of free movement of smoke gases, their energy is not in the stream is run multiple times, until he should pay most of their body heat oven. It warms it immediately.
The simplest design concept bell furnace.
The most common solution in current heating devices of this type is dvuhkolpakovaya scheme.
The algorithm works as follows. Air enters the firebox through ash pit. In the upper part of the furnace arranged yap.
In odnokolpakovyh furnaces are formed by gas damper. This is due to the fact that the hot gases, gathered under the hood, exclude "blowing" heavy cold air of the volume (compare with stopper holding the water in upside glass).
If the oven dvuhkolpakovaya, the thrust occurring at the second cap, making damper unstable. Previously, it was the primary reason because of which such furnaces is practically built.
When igniting furnace primarily burn the most light and active fractions. At this stage, the combustion process is comparable to the pyrolysis mode. Kuznetsova furnaces advantage is that they were originally designed for this mode. The gases released during pyrolysis afterburned under the arch of the first hood. In fact, this podsvodnoe space plays a role in the afterburner furnace pyrolysis type.
The combustion process which takes place under the first cap is actually self-adjusting. When the fuel in the combustion chamber flares intensive than required, then:
- emerging beneath a gas "cushion" afterburning gas expands into a single, affordable for this side down;
- This leads to a complication of coming down the outflow of the cold gases;
- reduction outflow weakens rod;
- burning intensity decreases.
When combustion occurs weakening backlash. At the final stage of the furnace, where combustion goes to the inactive mode or the step dotlevaniya remaining coals, both the cap moving operation on heat receiver (similar to channel furnaces). They simply gather additionally heat leftovers.
But at this stage the benefits of bell furnaces clearly expressed. The furnace channel, in accordance with Bernoulli's Law, most of this heat escapes into the exhaust pipe. A cap for substantially all of it will go on heating of the walls.
If a strong wind blows outside, the channel-type furnaces post-combustion process has to be interrupted, raking from the firebox not dogorevshee fuel and coal, and then close the damper. Otherwise, the oven cools down very quickly.
The bell-type furnaces such problem does not exist in principle. Sharply widening passage from the chimney to the outside cover exclude drafts in the furnace. Therefore, the fuel can be completely afterburned.
The question of stability of gas damper can be solved in 2-uhkolpakovyh furnaces, using the following technical solution. Distance №1 annular gap (between the outer wall of the cap 1 and the inner wall of the second) must profit over the same distance №2 (between the inner wall of the cap 1 and the firebox).
An ideal embodiment of the furnace construction is considered a product circular in cross-section (as in papers Groome Grzhimailo). The outer casing of the furnace, in such a case, at the same time plays the role of the 2nd cap. In it also has its own "postcombustion zone", which are thermochemical reaction, located under the vault of such a furnace.
It is here that the neutralization of unburned gases, as well as various oxides of nitrogen. These arise due to significant combustion temperatures in excess of this rate for channel furnace (flame). Therefore, only comes into the flue pair H2O and CO2. Such a furnace originally made from metal.
They can lay out and brick. However dvuhkolpakovoy brick furnace is very difficult, technically, to equip the cleanout door. And the question of cleaning is also very problematic.
This problem has been to bypass the change in approach to the placement of caps. Instead matryoshka principle uses cascading sequence. №2 cap is mounted on the hood №1. A chimney connecting them is performed from the rear part of the furnace. Such an arrangement reduces the efficiency of up to two percent.
With any solution to the second cap perfectly fit, if necessary, registers hot water preparation. On the efficiency will not be affected, since the main heat oven receives from the 1st cover.
The increase in fuel costs was an additional inducement for the revival dvuhkolpakovyh versions furnaces. The registers in the second boiler not violate combustion mode, and the cap 1, laid with bricks of low index thermal conductivity, excellent insulator protrudes from the high temperature stage of the parasitic heat losses type.
In the second cap gases flow with temperatures:
- sufficiently low that the heat exchangers can be used, made from conventional materials, excluding necessary burn-counter or sedimentation of carbon black;
- high enough for efficient heating of water. When the value efficiency = 80%, the gas temperature is given range (200-400) ° C.
Advantages of the structure under consideration
Comparison bell furnaces with channel allows note their considerable resistance to possible deformation loads. The product requires a minimum of time to warm up and retains heat for a long time, even if the valve is open.
Such a furnace characterized by:
- Long service life;
- minor amounts of soot. Almost all of this is burnt to the state of ashes;
- Efficiency of such furnaces ≥ 80%;
- masonry technology, even novice Pechnikov available. Suffice it to strictly follow poryadovkoy;
- available heating furnace body system outperforms similar construction in channel furnaces;
- Ease of maintenance. It needs cleaning considerably less frequently other structures brick kilns;
- It can be erected at the sites for any purpose (house, room, office, apartment, etc.);
- Currently, there are over one hundred drawings embodiments (poryadovok) and circuits dvuhkolpakovyh furnaces of different configurations, and destination volumes;
- It does not require special calculation of the chimney draft and height;
- It takes a minimum time for kindling;
- Allowable installation significant heating elements;
- the furnace body is uniformly warmed (Top / Bottom);
- It is able to retain heat for a long time.
Put a bell-type furnace
Baking, ideal in theory, well-warmed, in practice, cooked and driers, it is required to lay down and to use the right materials properly. This is true doubly so when it comes to furnaces of this type.
In dvuhkolpakovyh furnaces thermal load on the material is extremely high. Therefore it is easy to make a mistake, and perform a similar construction with thick walls. The fire will burn in it, but instead of the expected heat get the smoke and soot.
Analysis poryadovok Kuznetsova furnaces for various purposes, which are based on 2-uhkolpaktovy embodiment, (Heating and cooking, for the bath, with the installation of the boiler a bypass, etc.), reveals a very a characteristic feature. Unit NvydEqual to 500 W / m² surface of the outer material is consumed less than about 1.5 times than in the conventional product structures.
This has as a plus (cheaper construction due to the necessity of a smaller number of bricks and mortar for masonry) and minus. Such products have high requirements for the development and strict compliance with all technological nuances of doing masonry. Since the actual thermal loading, safe for thick-walled furnace able to destroy thin wall already at the booster stage of the furnace.
Structural Mechanics must also be close and clear Pechnikov, who decided to put their hands bell-type furnace. The simplest confirmation this thesis - the strength characteristics of the wall, lined with using a solution of a clay if its thickness is reduced, fall much more rapidly than cement masonry. This places high demands on the foundation of such a furnace. Pecnik obliged to strictly follow the recommendations poryadovkoy author, with whom he works. Moreover, not only the regeneration of the foundation, but later on all the other stages of the furnace laying.
A priori high loads acting on the materials from which any pattern made bell furnaces development Kuznetsov initially imply a willingness to study the construction of the stove-fitter in detail and follow the principles of engineering, having the status of fundamental.
Their fundamental principle is floating firebox. It is laid out of refractory bricks (refractory). The most popular brands are the W-5 and SB-8. The rest of the furnace body is put ordinary ceramic bricks, marks M150 and from above.
Recall, floating, it is called because:
- Around the firebox on all sides, or in strictly defined poryadovkoy field formed dry seal.
Equipment of its performance is as follows. After completion of laying the last row of refractory bricks, made the removal of masonry mortar from all the joints between them and ceramic brick. In the resulting void insert special pads that are made from different types of mineral board. The most commonly used kaolin and basalt. Perhaps the use of other technologies that are sure to stipulate in the specification, available for a specific furnace.
- Disconnectedness modules. This principle shall be strictly observed. Firebricks in any variants should not be inserted into the grooves between the ceramic bricks (the reverse is also true), even if there is damping joints.
The heat capacity of firebrick and TCRs differ considerably from those that have ordinary ceramic bricks. Therefore furnace, in communication with the presence of the main furnace body just sever already laying on the kindling stage.
It is therefore required to carry out the firebox for such furnaces as quite compact module inserted in a slot prepared with ceramic bricks. Thus there are a number of technical nuances providing exhaust gas through the chimney.
It is very important to use only the material named in the specification to the furnace, as well as specified in poryadovkoy. Constructions of such furnaces and high-calculated. Therefore, replacement of a very negative effect on the performance of the finished product. In the best case, the oven will have to be repaired. At worst, completely disassemble and share in new ways.
practical steps
In this article we will cover just the basics of practical masonry. Help to understand the issue in more detail allows acquaintance with videos that are available in abundance on the Internet.
For example, here:
If you want to look into the matter thoroughly and get to work "fully armed", be sure to buy a textbook on the masonry ovens. For example, V. Simakov "Stoves, fireplaces, barbecue." Moscow, Eksmo, 2011.
The site I.V.Kuznetsova in the bell section of the furnace, the drawings (hereinafter referred poryadovkoy) in the furnace for any purpose, power and configuration is available for reference and downloading without restrictions.
materials
If you plan to put the stove in one of the existing projects, then you should get on it two documents: a specification in which lists all the necessary materials in variant: the material name / brand / required amount / average price market. The last item is required to specify the date of decision of the masonry oven.
As a rule, regardless of the selected options for the future bell furnace, for the construction of its need to purchase:
- Refractory mastic (special dry mix masonry firebrick);
- Refractory bricks (chamotte);
- Ceramic single brick (from M150 and above);
- Materials for the preparation of mortars for cement, clay, sand;
- Multilayered plywood sheet for formwork;
- Sheet steel for the floor in front of the furnace door;
- Valves and reinforcing wires;
- steel corner;
- Planed timber wood;
- Furnace fittings (valves, doors, dampers);
- Metallized foil;
- Hob (if heating and cooking stove);
- grate grate.
Tool
To be able to perform any process step in the manufacturing process of a brick bell furnace master will need:
- Electric drill with a special nozzle or mixer building;
- Saw disk;
- Bulgarian;
- Nippers and tongs;
- Trowel (float);
- Shovel;
- Level (preferably a laser).
A professional stove-maker, this list is much longer. Listed here are just a basic tool.
Ideally masonry oven should be concerned at the stage of building a house. It is much easier, cheaper and more efficient.
However, modern technology make it possible to fit the stove in the finished house. Such work requires more time and cost, as well as additional calculations.
In conclusion of this article, we offer you a photo report on the masonry dvuhkolpakovoy Kuznetsova, boiler-heating furnace. With the app poryadovok and vertical sections.
Successful work!
