RU140082U1 - SOLID BOILER COMBUSTION CHAMBER - Google Patents

Abstract

The combustion chamber of a solid fuel boiler, containing a vertical screen made in the form of a metal cylinder, a secondary air supply pipe to the combustion chamber and nozzles for the secondary air to flow inside the combustion chamber, characterized in that the screen is made with double sealed walls whose height is equal to the height of the combustion chamber.

Description

The proposed utility model relates to a power system and relates to the combustion chamber of a solid fuel boiler, mainly for biofuel in the form of pellets.

The well-known "Heater for piece fuel" (US 4565184 F24B 9/00; F24H 9/18; F23K 3/14, publ. 21.01.86). The patent describes the design of a solid fuel boiler, comprising a retort for fuel combustion, a combustion chamber and a heat exchanger. The combustion chamber is located directly above the retort. A cylindrical heat exchanger is located around the combustion chamber. Hot gases move upward in the combustion chamber and downward in the gap between the combustion chamber and the heat exchanger.

A solid fuel auger and nozzles for supplying primary air are built into the retort. The combustion chamber is made in the form of a vertical cylinder made of refractory bricks. Directly below the combustion chamber is adjacent to the secondary air supply device, in the form of a hollow ring with nozzles. Shielding the combustion chamber with refractory masonry allows you to increase the temperature in the chamber, achieve more complete combustion of the fuel and reduce harmful emissions.

The disadvantage of this design is the large weight and dimensions, as well as the thermal inertia of the refractory. As a result, heating the combustion chamber takes a lot of time, during which the combustion does not occur optimally. Another disadvantage of the analogue is the lack of a secondary air heating device, which also reduces the efficiency of the combustion process.

The well-known "Boiler for continuous operation on solid fuel" (WO 97/31224 F24H 1/36, F23K 3/16, F23N 1/06, F23B 1/36, publ. 08/28/97). The patent describes a solid fuel boiler design comprising a combustion chamber and a heat exchanger. A cylindrical heat exchanger is located around the combustion chamber. Hot gases move upward in the combustion chamber and downward in the gap between the combustion chamber and the heat exchanger.

In this patent, the design of the combustion chamber is divided into two parts. The lower part is made in the form of a cylinder lined with refractory, and has a device for supplying fuel, primary and secondary air. Secondary air passing through the channels through the refractory is heated, which increases the efficiency of combustion. The upper part of the combustion chamber is made in the form of a vertical metal cylinder. The upper and lower parts of the combustion chamber are connected using a tapering nozzle.

Shielding the lower part of the combustion chamber with refractory - increases the temperature and efficiency of combustion. At the same time, shielding the top with a metal cylinder is clearly not enough. It is known from the theory of heat transfer that a metal sheet reflects half of the radiant energy entering it and passes the remaining 50%. Two sheets reflect 2/3 of radiant energy, etc. (Greberg., Erk S.I. Grikul W. Fundamentals of the theory of heat transfer. Publishing house of foreign literature. Moscow 1958, p. 512)

Another disadvantage of the analogue is the large weight and dimensions, as well as the thermal inertia of the refractory.

The closest in technical essence and the achieved result to the proposed utility model is a pellet boiler company OkoGep, listed on the website: http://www.pelletsheizung.de/de/produkte/pellematic.html, adopted for the closest analogue (prototype).

The boiler, according to the prototype, contains a grate for burning fuel, a combustion chamber and a heat exchanger. The combustion chamber is located directly above the grate. A cylindrical heat exchanger is located around the combustion chamber. Hot gases move upward in the combustion chamber and downward in the gap between the combustion chamber and the heat exchanger.

The grate has built-in fuel and primary air supply devices. The combustion chamber according to the prototype consists of a screen — a metal cylinder, in the lower part of which a secondary air supply device is integrated, which is a metal sealed rim with a supply pipe and nozzles for the discharge of secondary air. In the rim in direct contact with hot gases, the secondary air warms up well.

In addition, in the design of the prototype, in contrast to the above counterparts, there is the possibility of recirculation of hot gases over the grate. This helps to heat the torch root and improves the combustion mode.

The design of the combustion chamber is simple, light in weight and dimensions. It warms up quickly and immediately starts to work effectively.

The disadvantage of the combustion chamber of the prototype is that it has large losses in radiant energy and, accordingly, the temperature in the combustion chamber is less than it could be with a more efficient shielding. All this increases the amount of harmful emissions, primarily carbon monoxide (CO).

The objective of the proposed utility model is the improvement of the combustion chamber in terms of increasing its heat-insulating capabilities.

The problem is achieved in that in the combustion chamber of a solid fuel boiler containing a vertical screen made in the form of a metal cylinder, a secondary air supply pipe to the combustion chamber and nozzles for secondary air to flow inside the combustion chamber, the screen is made with double sealed walls, the height of which is equal to the height combustion chambers.

The technical result from the use of a utility model is to reduce heat loss, increase the temperature in the combustion chamber, more complete combustion of fuel.

The technical effect is most noticeable when burning fuel from wood. When burning liquid and gaseous fuels, the proportion of primary air prevails, the proportion of secondary air is negligible. Accordingly, the amount of heat released before the secondary air supply is already approaching the total heat of combustion. The temperature in the combustion chamber is close to maximum and there is no task of shielding the combustion chamber after the secondary air supply.

When burning wood fuel, the ratio between primary and secondary air is the opposite. (Golovko S.I., Koperin I.F., Naydenov V.I. Energy use of wood waste. Page 35) The share of secondary air prevails (up to 85%). Accordingly, the heat generation before the secondary air supply makes up only a small part of the total heat of combustion and to increase the temperature of combustion, the task of shielding the combustion chamber arises.

The figure shows a cross-sectional drawing of a combustion chamber of a solid fuel boiler.

Structurally, the combustion chamber of the solid fuel boiler of FIG. 1 contains:

1 - combustion chamber;

2 - screen;

3 - pipe supply secondary air into the combustion chamber;

4 - nozzle outflow of secondary air.

The combustion chamber 1 is covered by a screen 2, made in the form of a metal cylinder, with double sealed walls, the height of which is equal to the height of the combustion chamber 1.

The proposed utility model works as follows.

Fuel burns on the grate in the presence of primary air. In the process of heating the fuel, combustible gases are released from it, which are burned in the combustion chamber 1 in the presence of secondary air. Secondary air enters the combustion chamber 1 through the pipe 3 and nozzle 4.

Hot gases move upward in the combustion chamber 1 and downward in the gap between the combustion chamber 1 and the heat exchanger.

The implementation of the screen 2 with double sealed walls helps to reduce heat loss by three times, as a result of which the temperature in the combustion chamber approaches the maximum possible, which ensures more complete combustion of fuel.

Claims (1)

The combustion chamber of a solid fuel boiler, containing a vertical screen made in the form of a metal cylinder, a secondary air supply pipe to the combustion chamber and nozzles for the secondary air to flow inside the combustion chamber, characterized in that the screen is made with double sealed walls whose height is equal to the height of the combustion chamber.

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