CS231017B1 - A method of supplying spillage air and apparatus for performing the method - Google Patents

Abstract

The subject of the invention solves the problem of gas temperatures for optimal desulfurization and prevention of sticky ash deposits. It will allow burning of non-balanced fuels and waste. It improves the environment by reducing exhalations. The essence lies in the fact that the gases developed from the burned fuel or waste are supplied with air necessary for perfect combustion gradually and depending on the cooling of the gases while simultaneously removing the heat that the gases develop. The temperature of the gases is maintained in the most favorable range during the process. The subject of the invention will find application in the construction of furnaces, thermal aggregates, energy and chemical equipment, euBarem, etc.

Description

(54) A method for supplying combustion air and apparatus for carrying out the method

The present invention solves the problem of gas temperatures for optimal desulfurization and avoiding the formation of sticky ash deposits. It will allow to burn non-balanced fuels and waste. Improves the environment by reducing emissions. The essence is that the gases produced from the combustion fuel or waste are supplied with the air necessary for perfect combustion gradually and depending on the cooling of the gases while the heat generated by the gases is dissipated. The gas temperature is maintained in the most preferred range during the process.

The present invention finds application in the construction of furnaces. of thermal aggregates, energy and chemical equipment, euBar etc.

2310.7

The present invention relates to a method for the combustion of solid, liquid and gaseous fuels or wastes by the special supply of combustion air and to a device for carrying out the method and is particularly suitable for fluidized bed combustion. It eliminates the problem of gas temperatures for optimum desulfurization and avoids the formation of sticky ash deposits.

Known fireplaces for the combustion of solid, liquid and gaseous fuels or wastes, including fluid fires, have combustion air supplied to the combustion space so that the combustion is as complete as possible over a relatively short gas path and the combustion temperature is maximally high. The negative consequences of this process include the reduced possibility of flue gas desulfurization as a result of the fact that calcium carbonate cannot be used for flue gas desulfurization at temperatures above 1273 K or the complete desulfurization is impossible, which is unbearable for its environmental consequences. Another adverse consequence is the softening and stickiness of the solid particles present in the gases. The particles adhere to the walls of the combustion plant and cause operational problems which significantly adversely affect the economy of the combustion plant.

The above-mentioned drawbacks are completely eliminated by the method of operation of the combustion apparatus and the apparatus for guiding the process according to the invention, which is based on the fact that the gases generated from the combusted fuel or waste are supplied with air necessary for perfect combustion gradually and the heat dissipated by the gases. The dependence of the air supply on cooling is intentional and is intended to keep the gas temperature within certain limits. The lower temperature limit is given by the flammability of the flowing gases. When dissipating heat, gases must not be cooled sufficiently to compromise reliable ignition. The upper temperature limit is affected by two requirements. The first is the condition that the temperature does not exceed a value that is optimal for flue gas desulfurization. The second condition is the need not to exceed the softening point of the solid particles contained in the gases and which, once they become sticky, adhere to the walls of the device.

The drawing shows a fluidized bed which is considered to be perspective, especially for the supposed brown coal.

The fluid grate 1 is located at the bottom of the furnace. 7 above the grid. the fluidized bed 6. A portion of the heat exchanger surface 6 of the heat exchanger is located in the space above the fluidized bed. In the space 4, a portion of the combustion air is supplied through the nozzles 4 in the gas-attenuation meter above the heating surface 4. Above, a further heating surface 2 is located in the direction of the gas flow, and in the space above it there are located nozzles 4 through which a further part of the combustion air is supplied. Similarly, the alternation of the heating surface and the air nozzles continues until all the combustible components contained in the gases are burnt out. It is then possible to sub-burn the ignition temperature and cool the flue gas to a temperature analogous to that of conventional boilers. The arrangement of the heating surfaces and the air nozzles can be selected vertically, horizontally or at an angle,

The activity of the device of the invention is as follows:

The combustion gases produced immediately after ignition of the fuel supplied to the furnace 6 are supplied with only a portion of the combustion air required to reach the temperature of the gases, e.g. 1,273 K. The amount of air supplied is sufficient to burn only the portion of the combustible gas. Further, the gases pass through the first heating surface 6 of the exchanger and transfer part of the thermal energy to the flowing fluid, which is typically water or spring. Their temperature drops after the first heating surface 6 to a temperature of, for example, 973 K, but must never drop to a temperature lower than the respective ignition temperature. Upon exiting the heating surface 4, a further portion of the combustion air is introduced into the gases through the nozzles 4, but only so that the temperature does not exceed, for example, 1273 K. The gases of this temperature are transferred to another heating surface 2 where they are cooled again eg 973 K. After leaving the second heating surface 2, a further proportion of combustion air is introduced into the space 6 through the nozzles 6, again in the amount necessary to reach a temperature of 1273 K. The process of cooling the gases and subsequently raising their temperature is repeated complete combustion of the combustible fraction of gases and then re-cooling the flue gas to a normal outlet temperature.

Claims (5)

SUBJECT OF THE INVENTION CLAIMS 1. A method for supplying combustion air to combustible gases in a furnace for the combustion of solid, liquid, gaseous fuels and wastes, characterized in that the combustion air is supplied to the combustion gases successively, intermittently and repeatedly in partial amounts which are less than the total amount of air required to burn the gases, after passing part of the air through the fluid grate, the gases are fed to the heating surface, then another part of the air is supplied to the gases through the air nozzles and partial air flow into the gases parts of the air through the nozzles and passing through the heating surface are repeated several times until the content of combustible fractions in the gases is reduced to a value close to zero. 2. Apparatus according to claim 1, characterized in that it consists of a fireplace (2) in which freshly supplied fuel generates burning gases, downstream of which a heating surface (4) of the exchanger is placed, downstream of which the combustion plant is located. space (5) by β nozzles (65 of the combustion air supply) and the heating surface (7) of the exchanger is followed by the heating surfaces (4, 7, 10, ...) of the exchanger and the combustion spaces (5, 8, ...) in which combustion air is supplied in an amount that is necessary to burn the gases and cool the flue gases. Device according to Claims 1 and 2, characterized in that it comprises alternately pleated heating surfaces (4, 7, 10) and spaces with air nozzles (6, 9, ...), the heating surfaces being directed vertically. Device according to Claims 1 and 2, characterized in that it comprises alternately arranged heating surfaces (4, 7, 10, ...) and spaces with air nozzles (6, 9, ...), the heating surfaces being guided horizontally . Device according to Claims 1 and 2, characterized in that it comprises alternately arranged heating surfaces (4, 7, 10 .....) and air jet spaces! (6, 9, ...) wherein the heating surfaces are inclined.