BG67330B1 - Smokeless combustion process method and device - Google Patents

Abstract

The developed method for smokeless combustion allows a possibility to eliminate emissions of fine particulate matters released into the atmosphere during the combustion of almost all types of fuels. The method is carried out by creating a catalysing layer (8) of glow-proof and heat-absorbing inert material . When the gases released during the combustion of fuel (5) in the combustion zone (6) enter the catalysing layer(8), they increase its temperature by about 100-200°С, higher than the temperature in the combustion zone (6), whereby they create conditions for complete combustion of all gases and fine particulate matters. The reason for the increase in temperature in the catalysing layer (8) is the presence of a large surface inside it and a decrease in the gas flow rate, which allows for a more complete oxidation process. When steam is involved in the combustion process, the catalysing layer (8) is most effective. The gas flow passing through the catalysing layer (8) has a completely finished combustion process. The catalysing layer (8) creates conditions for the production of smaller combustion chambers with lower cost and high performance. Then, when the heat exchange system (8) is integrated in the catalysing layer, the efficiency of the steam boiler is the highest and the heat losses are the lowest.

Description

Field of technology

The method is designed for application in all types of combustion chambers of steam boilers and thermal power plants using solid, liquid and gaseous fuels.

BACKGROUND OF THE INVENTION

Currently, what is being done to reduce harmful dust emissions in flue gases is the use of different types of filters (electrostatic, mechanical and water). The efficiency of these filter devices is low and they stop a small part of the solid particles released in the flue gases. There are many technologies that create conditions for improving the combustion process and reducing particulate matter. An example of this is the technologies used in incinerators for the disposal of hospital waste from publications GB 1118855 A and JPHO 7208711 A.

In the known technical solution GB 1118855 A the combustion takes place in three consecutive horizontal chambers. The combustion process begins in the first chamber, as through openings in the barrier between the first and second chambers the hot gases pass at a slower rate, whereby the oxidation process is more complete and the temperature of the gases entering the second chamber rises. In the second chamber, trays with catalysts arranged on them are placed one above the other. The liquids separated from them are returned to the first chamber for afterburning or collection in a container. Atmospheric air is added to the combustion gases from the second chamber for better oxidation of the combustion. Through an opening in the lower part of the second chamber, the gas flow passes into the third chamber, in which there is a labyrinth of barriers to reduce the speed of the gas flow and more complete combustion.

The second combustion chamber JPHO 7208711 A is rotary. In it, the oxidation process (combustion) takes place in three vertical chambers. Between the first and second chambers there is a labyrinth of ribbed ceramic plates that slow down the flow of fluid for better combustion. The second and third chambers are separated by a ceramic top with openings on which are placed ceramic cylindrical tubes with radial openings at the periphery, through which the gas flow passes into the third chamber. In this way the speed of the gas flow is reduced and the combustion process is better.

In these examples, the path of the combustion gases is extended by various technical solutions, which provides sufficient time for the oxidation reaction between hydrocarbon compounds and oxygen to take place. In addition, the combustion process takes place in three consecutive combustion chambers, so that the gas flow temperature remains low. The hospital waste incinerators in the last chamber must maintain a temperature of 1200 ° C, and this is done with an additional gas burner and a lot of atmospheric air, which eventually remains polluted.

Technical nature of the method

BG 67330 Bl

The task of the created method is to reduce or eliminate completely the fine dust particles.

This task, the developed method solves with the help of a device called a catalyst layer. It is placed in the combustion chamber running on solid, liquid or gaseous fuel above the combustion zone. The catalyst layer consists of pieces of heat-resistant and heat-absorbing material, the dimensions of the pieces being determined by the amount of treated gases and the velocity of the passing fluid required to maintain the combustion process.

The heated gases passing through the catalyst layer increase its temperature and a process of secondary combustion inside it begins. The cause of secondary combustion is the presence of unburned gases (incomplete oxidation process) and a large amount of fine dust particles. The temperature of the catalyst layer is one hundred to two hundred degrees (100-200 °) higher than the temperature in the combustion zone. For some types of coal this temperature difference is over 400 ° С.

Water vapor is included in the combustion process as a catalyst. The flue gases passing through the catalyst layer contain only fine dust particles.

The use of the catalyst layer increases the efficiency of the combustion chamber by more than 20%. The catalyst layer creates conditions for the production of small combustion chambers with low cost and high productivity. This is because a combustion chamber with a catalyst bed mounted has only one combustion zone (primary combustion), followed by the catalyst layer in which the combustion process ends. Then, when the heat exchange installation is integrated in the catalyst layer, the efficiency of the facility is the highest and the heat losses are the lowest.

Explanation of the attached figure

Figure 1 shows a drawing of a combustion chamber with grill combustion and a built-in catalyst layer.

An embodiment of the invention

In FIG. 1 shows an example of an embodiment of the method and device according to the invention, it comprises: a combustion combustion chamber 1, an air or air injection zone and steam 2 located at the bottom of a combustion chamber 1, an air and steam supply inlet 3 through the wall of the combustion chamber 1, fuel grill 4 mounted above the air injection zone 2, fuel (coal) 5 placed on the grill 4, combustion zone 6 located above the fuel 5, grill 7, catalyst layer 8 , placed on a grill 7, consisting of pieces of heat-resistant and heat-absorbing material, a heat exchanger 9 mounted so that a part of it is in the catalyst layer 8, an exhaust outlet 10 located in the upper part of the combustion chamber 1.

Use of the invention

In the drawing of FIG. 1 shows an example of the use of the invention, which works as follows.

In combustion chamber 1 the combustion process is carried out in the following order: through inlet 3 in the wall of combustion chamber 1 is injected air or steam air, which enters the injection zone 2 and passing through the fuel grate 4, enters fuel 5, as maintains its combustion in zone 6, through the grill 7 the burning gases enter the catalyst layer 8, which consists of pieces of heat-resistant and heat-absorbing material in which the catalyzing of combustion in the gas stream from zone 6. The hot gases increase the temperature of the catalyst layer 8. and it becomes higher than the combustion temperature in zone 6 by one hundred to two hundred degrees (100-200 ° C). In the combustion process through inlet 3, water vapor is included for the catalyst, at which the temperature in the catalyst layer 8 rises. The elevated temperature in the catalyst bed 8 creates conditions for complete combustion of all gases released during the combustion of fuel 5, as well as burns all fine dust particles released in the combustion process. The heat exchanger 9 is mounted so that one part of it is located above the catalyst layer 8 and the other is inside the layer. All gases passing through the catalyst layer 8 leave the combustion chamber through the exhaust outlet 10.

Claims (2)

Method for a smokeless combustion process realized in a combustion chamber operating with solid, liquid or gaseous fuel, where in the combustion zone the combustion process begins, supported by the supply of atmospheric air, where the gas flow obtained during combustion passes through the grill and enters in a catalyst layer, characterized in that during the combustion process in the combustion zone (6) water vapor is supplied as a catalyst, and inside the catalyst layer (8) heat exchange takes place in a heat exchanger (9), followed by the cooled gas flow exits through the exhaust outlet (10) A smokeless combustion process device implementing the method according to claim 1, comprising a combustion chamber in the lower part of which a fluid injection zone is located, above which a fuel grate is mounted, wherein the fuel is placed on the fuel grate, and above the fuel is a combustion zone with a grill located above it, on which a catalyst layer is placed, characterized in that the catalyst layer (8) consists of pieces of heat-resistant and heat-absorbing material, where the heat exchanger (9) is mounted so that one part of it is in the catalyst layer (8), and another part is located above the catalyst layer (8), and in the space above the heat exchanger (9) there is an outlet for exhaust gases (10)