RU2612233C2 - Solid-fuel boiler - Google Patents

Abstract

FIELD: fuel.

SUBSTANCE: invention relates to solid fuel combustion devices, preferably with lower combustion zone, and can be used in heat engineering, chemical and other industries. Set task is solved by fuel boiler containing, in fact, furnace, attached to it heat exchanger chamber with chimney and grate located beyond combustion zone in furnace lower part with slots made in it for ash removal into ash box arranged under grate, differing by fact, that grate consists of stationary metal plate inclined towards gases exit from furnace, in middle and lower parts of which two or more rows of welded into it pipe sections are arranged with length of 3–4 cm with through holes, covered from above along grate axis with protective angles to prevent ingress of fuel and ash into holes, and on plate back side air passage through pipes sections mechanical shut off device is made.

EFFECT: technical task is enabling of boiler operation power control in wide power range from 5 % to 100 % while maintaining optimum conditions of fuel combustion and high efficiency.

1 cl, 2 dwg

Description

The invention relates to a device for burning solid fuel, mainly with a lower combustion zone, and can be used in the power industry, chemical and other industries.

There are well-known furnaces and boilers with lower combustion in the form of a large firebox, such as a fuel storage hopper, in which combustion at the very bottom takes place on a horizontal grate, while air enters through the grate and ash is removed through the grate. However, such furnaces work well only on lump fuel.

When using fine-grained fuel - pellets, wood shavings, sawdust, loose peat and so on, small fuel, not burned, wakes up through the grate and is irretrievably lost, reducing the efficiency and efficiency of the furnace or boiler, since when the fine-grained fuel is lowered into the burned place, the air outlet completely closes through the grates and burning occurs only near the very exit of the furnace, which can cause the cessation of burning.

If you reduce the amount of air supplied to reduce the burning power, the combustion temperature above the grate will decrease, worsening the conditions for pyrolysis and gas generation, and when the temperature drops to 400-450 degrees Celsius, the combustion goes into decay with low efficiency and the discharge of unburned particles to the outside, and power until deterioration in the quality of combustion does not decrease by more than 50-60%.

Since in severe frosts or during the initial heating of the room, the capacity of the furnace or boiler should be 5-8 more than with supporting combustion or for heating in the thaw (and in summer only for hot water supply up to 10-15 times less), we can talk about a large shortage of furnaces or boilers with lower combustion, expressed in an insufficient degree of regulation of their power, which leads to a significant excessive consumption of fuel.

So, for example, a furnace for burning low-grade coal is known (RF Patent No. 2306487, 2004), comprising a casing made with a narrowing in the upper part, equipped with a lid, doors for loading fuel and unloading ash and air intake windows into the furnace, installed in the furnace of the furnace, the grate, forming the blast channel for burning fuel, and the grate, forming the blast channel, installed inside the burned fuel, while the furnace body has a rectangular shape in cross section, grate grates are made around the perimeter of the furnace, providing air supply for burning fuel, and shelves with openings are installed to which four air intake panels are installed using cotter pins that create blast channels for the indicated grate grates, and two fire grates are installed in the furnace of the furnace, forming blast channels for burning fuel, and the blast channel installed inside the combustible fuel is located in the center of the blast channel for burning fuel. The disadvantage of this design is the lack of a system for controlling the flow of primary air, the supply of secondary air to the afterburner located above the narrowing in the upper part is not provided. Analysis of various types of furnace devices showed that they all have drawbacks. Designs of layered furnaces with fixed grate grids have a significant mechanical underburning due to uneven air supply over the surface of the grate grate, and in this connection crater burning and slagging of grate grates arise.

Known heating boiler TROX, selected the closest analogue (http://klimat.zp.ua/teplooborudovanie/kotli_tverdotoplivnie/kolton_trox40_trox), a distinctive feature of which is the principle of lower combustion. Individual elements of the boiler are made of sheets of 6-8-10 mm due to the aggressive action of organic substances. The boiler heat exchanger consists of vertical panels, and a hopper and additional doors are installed directly above the combustion chamber. The combustion chamber has a block-shaped cast-iron grate, a ceramic lining and a number of aeration holes to ensure the most efficient combustion process. The TROX boiler is adapted for burning biomass (sawdust, wood shavings, wood chips, briquettes, wood waste). In the absence of these types of fuel, coal can be periodically burned by removing the hopper. TROX is simple and trouble-free in daily operation.

However, the disadvantages of the described technical solutions are the impossibility of regulating the boiler power over a wide range.

The technical task is to ensure that there is no failure of unburned small fuel through the grate and regulate the power of the boiler in a wide range from 5% to 100% of power while maintaining optimal conditions for fuel combustion and high efficiency.

The problem is solved by a fuel boiler containing the furnace itself, a chamber for a heat exchanger with a chimney attached to it and located outside the combustion zone in the lower part of the furnace, the grate with slots for removing ash into the ash box located under the grate, characterized in that the grate consists from a fixed metal plate inclined towards the exit of gases from the furnace, in the lower part of which there are two or more rows of pipe sections welded into it 3-4 cm long with through holes, are covered x from above along the axis of the grate with protective angles to prevent ingress of fuel and ash into the holes, and on the reverse side of the stove there is a device for mechanically blocking the passage of air through pipe sections.

In FIG. 1 schematically shows a boiler with a grate, and in FIG. 2 shows a boiler in section, where:

1 - pipe sections,

2 - device for blocking the passage of air,

3 - protective corners,

4 - fixed metal plate,

5 - grate,

6 - ash box

7 - firebox,

8 - the furnace body.

With all openings of pipe sections 1 open, the burning power will be maximum. As the number of open pipes decreases, the furnace power will decrease accordingly.

The amount of air will be optimal for burning the amount of fuel that is above each hole, so the fuel combustion efficiency will be high even at the lowest power.

It is possible to leave combustion only over one hole (less than 5% of the maximum power of the entire furnace or boiler — such as a pilot light in gas burners) for a “standby mode”, in which burning is resumed at the required power without flooding, as in normal cases, but simple opening the right number of holes for the right power level.

The ash is removed at the very bottom of the inclined surface of the plate 4 through the openings of the grate, leading to the ash box 6.

Fuel located on an inclined grate during the combustion of fuel located in the combustion zone, goes down and takes the place of a burned one. Protective squares 3 do not allow even the smallest fuel or ash to get into the openings of the pipe sections and block the access of combustion air.

By means of openings for the passage of air, protected on the sides by pipe sections and corners from above, by means of a device 2 for closing part or all of the air passages, it is possible to control the burning power in the widest possible range - from 5% to 100%.

The technical result is to eliminate the failure of unburned fuel under the grate - thereby increasing the efficiency and creating optimal combustion conditions by reducing the volume of combustion and the amount of incoming air, which reduces the total burning power without compromising its quality.

Claims (1)

A solid fuel boiler containing the furnace itself, a chamber for a heat exchanger with a chimney attached to it and located outside the combustion zone in the lower part of the furnace, a grate with slots for removing ash into an ash box located under the grate, characterized in that the grate consists of a grate the side of the gas outlet from the furnace of a fixed metal plate, in the lower part of which there are two rows of pipe sections welded into it, 3-4 cm long with through holes, covered from above along the axis of the fire grate squares to prevent fuel and ash from entering the holes, and on the back of the stove a device was made for mechanically blocking the passage of air through pipe sections.

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