UA130855U - PELLET Gravity Burner - Google Patents

Abstract

A pellet gravity boiler burner having a collapsible weld body consisting of two vertical side walls and two end grate grilles, the grate located on the air inlet side inclined and the grate grille facing the flue gas outlet , made vertically, in addition, in the lower part of the burner housing between the grate is placed ash distributor made of refractory metal profile rectangular or triangular or hexagonal or circular section of length equal to or less than the width of the burner body.

Description

The useful model belongs to heating systems of technical, industrial and residential premises, in particular to heating systems operating on pellet fuel, namely to pellet gravity boilers and directly to burner designs.

The high cost of heating when using traditional boilers that use electric current, gas, coal or wood as energy sources forces us to look for more efficient sources.

Pellet boilers are solid fuel boilers that use pellets (pressed pellets from wood shavings) as fuel. Despite the fact that pellet boilers are a relatively new type of heating equipment, they quickly gained popularity due to their advantages: independence from central energy sources, low fuel prices, environmental friendliness, high efficiency and quick payback, maximum automation and ease of operation.

Pellet boilers have a special design, which consists of a furnace (one or more combustion chambers), heat exchangers (chimneys) and a fuel hopper. From the fuel hopper, the pellets are fed into the furnace of the boiler, where they are efficiently burned on specially equipped grates. In the vast majority of boilers, pellets are fed into the furnace using a mechanical auger or a motor-reducer in automatic mode, thanks to which the boiler can operate without human intervention for several days. However, both the mechanical screw and the motor reducer work from sources of electrical energy. In the event of a lack of electricity, the operation of such a boiler stops. The pellet boiler, which uses gravity fuel supply to the combustion chamber, does not need any electromechanism for its operation. That is, the advantage of boilers with gravity feed of pellets is independence from power supply systems.

From the state of the art, a pellet boiler is known according to the patent of Ukraine for a utility model Mo OA 117900 OO, IPC: g238 50/12, dated 10.07.2017. The pellet boiler burner contains two pellet combustion chambers, and the primary chamber has a grate in the form of a basket, and the secondary combustion chamber contains a flat afterburning grate with a useful sieving area of at least 80 95 of the total area of the grate. The disadvantage of the burner design is the complexity of the design consisting of two combustion chambers, the unstable combustion process, and the possibility of ash accumulation in the combustion zone.

The closest analogue of the proposed burner design in terms of technical essence and set of features is the gravity pellet burner according to the international application UUO 2014148956

JSC, IPC: g238 50/04, R23B 60/02, dated 09/25/2014.

The burner includes a body with an open front end, a fuel supply channel, a combustion chamber located under the fuel supply channel, the body of which is close to a horizontally elongated parallelepiped or a cylinder, limited on the front end of the body by an inclined perforated plate (grill), and on the back side the end of the housing with a straight perforated plate, the width of which is equal to or less than the internal width of the combustion chamber housing. Below the case there is a bottom perforated plate, which is installed in such a way that it forms slits for spilling ash from the side of the front and back plates.

The disadvantages of the known device are the uneven distribution of fuel in the combustion chamber, the accumulation and sintering of ash in the fuel zone, which causes uneven heating of gases and, as a result, an unstable combustion process, which leads to further smoke in the room where the boiler is located and to self-extinguishing of the boiler.

The burning of pellets takes place in the lower part of the combustion chamber between the side walls and the end grates on the floor plate. In the process of burning, ash accumulates on the bottom plate and the combustion zone moves to the upper part of the burner, to an area with insufficient oxygen. Under the pressure of new pellets falling from above from the hopper into the burner, the combustion zone shifts downward again, part of the ash is compressed and sintered into a cake, which prevents it from falling into the ash pan. This is especially noticeable at low burner capacities, when the air entering the combustion zone is not enough to partially blow ash from the combustion zone into the ash pan. At first glance, it would be possible to solve the problem by increasing the size of the gaps between the grates in the lower part of the burner, however, this solution will lead to a significant spillage of pellets into the gap even before the boiler is ignited, as well as spillage of partially burned pellets into the ash box until ash is formed and the robot the boiler will become unstable or completely impossible. If the size of the gap between the grates is reduced, the cake of pressed ash will not allow the burner to work normally.

The useful model is based on the task of improving the design of the burner, increasing the efficiency of pellet burning processes and self-discharge of ash from the combustion zone.

The task is solved by the fact that the burner of the proposed pellet gravity boiler, whose body is made in the form of a box, which consists of two vertical 60 side walls and two end grates, contains an ash distributor made of a refractory rectangular or triangular or hexagonal metal profile , or round section is placed in the lower part of the burner body between the grates.

Gaps are formed between the grates and the distributor for pouring ash into the ash box. The installation of the distributor in the lower part of the burner between the grates contributes to the fact that the pellets coming from above, under the influence of gravity, push the ash down and the sintered cake of ash, falling on the narrow edge of the distributor, is crushed and falls into the gaps between the grates and the distributor.

The proposed design of the burner prevents the accumulation and sintering of ash in the combustion zone, promotes the maximum combustion of pellets and thus increases the efficiency of the boiler.

The essence of the useful model is explained by the drawings, which schematically depict the burner of the pellet boiler, the cross-section of the ash distributor, and the gravity pellet boiler.

Fig. 1 - general view of the burner;

Fig. 2 - top view of the burner;

Fig. C - front view of the burner;

Fig. 4 - side view of the burner;

Fig. 5 - cross-sectional shape of the ash distributor;

Fig. 6 - general view of the gravity pellet boiler.

The burner of the pellet gravity boiler (Fig. 1 - Fig. 4) has the shape of a box, which consists of two vertical side walls 4, 5 and two end grates 1, 2, and the grate 1, located on the side of the air inlet, is made of an inclined , and the grate 2, located on the side of the flue gas outlet, is vertical. In the lower part of the burner body, between the grates, there is an ash distributor C, made of a metal profile of either a rectangular (Fig. 5a), or triangular (Fig. 56), or hexagonal (Fig. 5c), or round (Fig. 5d) section. The length of the distributor Z is equal to or less than the width of the burner body.

Structurally, the pellet gravity boiler burner is a prefabricated and welded structure made of refractory material. The burner works as follows.

Pellets from hopper 6 are poured into the burner. Ignition is carried out through hole 7 in the front part of the burner, through which air is supplied. Pellet burning is supported by

From the natural draft of air through the front part of the burner. The supply air passes through the blower 7 in such a way that it ensures the burning of only the lower layer of pellets on the grates 1 and 2 of the burner and the ash distributors З and makes it possible to ignite the upper layers, since the excess air is drawn out with the flue gases directly into the chimney. The pellets burned in the burner, through the holes of the grates and the gaps between the grates 1, 2 and the ash distributor C, fall directly into the ash box or on the afterburning grate of the secondary combustion chamber, if such is provided by the boiler design. As the pellets burn in the burner, new pellets from the hopper are brought to it under the influence of gravity. Depending on the required power of the boiler, with the help of an air damper (not shown in Fig. b), which is installed in the appropriate position at the burner inlet, it is possible to change the air flow entering the combustion chamber, that is, to regulate the combustion process.

The proposed design solution ensures boiler operation without additional maintenance for 24-36 hours, depending on the intensity of combustion at full load.

Claims (1)

USEFUL MODEL FORMULA The burner of the pellet gravity boiler, which has a prefabricated and welded body, which consists of two vertical side walls and two end grates, and the grate located on the side of the air inlet is made inclined, and the grate located on the side of the exit of flue gases , made vertical, which is distinguished by the fact that in the lower part of the burner body between the grates there is an ash distributor, made of a refractory metal profile of rectangular or triangular, or hexagonal, or round section, the length of which is equal to or less than the width of the burner body.