SU1044894A1 - Method of decontaminating waste gases - Google Patents

Abstract

METHOD FOR DISPOSAL OF DRAIN GASES by oxidation of toxic impurities contained therein by supplying additional gas to the fuel and subsequent regenerative heating of waste gases with heat from decontamination products, characterized in that, in order to reduce the formation of oxides of nitrogen, additional gaseous fuel is put into the waste heat source. in the ratio from 6: 1000 to 1 3: 1000. Gas-tight top ioo / laooipastae moiiMuSi Bxsd Fug1

Description

The invention relates to the disposal of waste gases by burning them, in part, in regenerative apparatuses, and can be used in the chemical, petrochemical, engineering industry, etc. A method is known for deactivating waste gases of chemical plants, concluding in combustion from gases containing organic impurities in boiler plants by passing them - along with blowing air through a layer of fuel located on the column, egg grid 1, the disadvantage of the known method of deactivating zhivani offgas himl iCal production is a way vanie nitrogen oxides in the high-temperature combustion zone. There is also known a method of burning waste gases, which consists in burning waste gases in a mixture with natural gas in a ratio of 2: 1 to 1; 2 21. The disadvantage of this method is the formation of nitrogen oxides when burning a high-calorie mixture. The closest to the offeror of the technical essence and the Morviy effect is the method of decontamination of waste gases by oxide of the junion from the toxic impurities retained in them when additional fuel is supplied and the subsequent regenerative heating of the waste gases with heat of decontamination products L3}. is the formation of nitrogen oxides in the flame of the gaseous fuel. The purpose of the invention is to reduce the formation of nitrogen oxides. The goal is achieved by the fact that according to the method of decontamination of waste gases by oxidizing toxic impurities contained therein by supplying additional gaseous fuel and subsequent regenerative heating of waste gases with the heat of neutralization products, additional gaseous fuel is introduced into the waste gas by regenerating its heating from 6 - LOOO up to 13; 1000, The amount of gaseous fuel introduced into the waste gas depends on the caloric content of the waste gas, which can vary from Zero to such a limit, when the need for additional fuel supply disappears, from the degree of heat regeneration f which for regenerative apparatuses is at a distance of 0.70,9p from the neutralization temperature p which is on average 800900 ° C, from the calorific value of the gaseous fuel ( for natural gas, it is 33000-34000 kJ / HNr / With a ratio of natural and waste gases from 6: 1000 to 13: 1000, zero caloric value of the waste gas, the degree of heat recovery in the regenerative apparatus 0.7-0.9 and calorific value natural abilities 33000-34000 kJ / nm gas is provided for the process of decontamination of waste gas at a temperature of 800900 ° C without the formation of nitrogen oxides. At a ratio of natural and waste gases, the inlet to the apparatus is below 6: 1000, the zero calorific value of waste gas, the calorific value of natural gas 3300034000 kJ / nm , with the highest degree of heat recovery 0.9, the mixture does not burn and the process of thermal deactivation of waste gas does not occur. When the ratio of natural and waste gases at the inlet to the apparatus is higher than 13: 1000, zero caloric content of the waste gas, the calorific value of natural gas is 33,000 3-4,000 kJ / nm, a low degree of heat recovery is 0.7, the temperature of the neutralization process increases, which leads to fuel overspending thermal decontamination process; FIG. 2 shows an apparatus for decontamination of waste gas; Fig. 2 is a graph of temperature distribution along the length of the regenerative apparatus, when gaseous fuel is fed into the afterburner (curve Ij, when mixed with waste gas before entering the apparatus (curve 2). Regenerative apparatus 1 contains stationary refractory nozzles 2 and chamber 3 Afterburning. Gas burners 4 are provided for heating the nozzles. The device is equipped with pipelines for supplying the waste and venting gas to be neutralized. To change the direction of the gas flow movement, a reversing valve 5 is provided. The exhaust gas is discharged through the pipe 6. The regenerative apparatus works as follows: Under the action of a vacuum in the exit duct, the mixture of the discharge gas with natural gas in the ratio from b: 1000 to 13: 1000 enters the regenerative apparatus through a refractory nozzle “preheated in the previous cycle, As the mixture warms up, natural gas is burned out and the toxic impurities of the waste gas are burned out, which ends in Ks1mer 3 of afterburning. From the afterburning chamber, the neutralized gases pass through

the second nozzle, giving it heat, then is released into the atmosphere. As the first gas cools down in the course of the gases and the second warms up after a certain period of time with the help of the change-over valve 5, the direction of gas movement is reversed.

In studies of the experimental apparatus, for the purpose of comparison, gaseous fuel is supplied to the afterburning chamber and directly to the waste gas before entering the apparatus.

The research results are summarized in the table.

The supply of gaseous fuel to the waste gas prior to entering the regenerative apparatus makes it possible to eliminate the high-temperature zone of combustion of the fuel gas, which is a source of formation of nitrogen oxides, and to increase the residence time of toxic impurities in the zone of neutralization.

Using the proposed method 9 to eliminate waste gas, along with a decrease in the yield of nitrogen oxides, reduces the consumption of gaseous fuels. This is achieved by eliminating the supply of cold air required for burning the gaseous fuel to the afterburner and using the oxygen contained in the waste gas.

Supplying additional fuel and air through the burners

With the addition of additional fuel to the waste gas

Operation mode

The temperature in the afterburner.

With the supply of additional fuel and air through the burner

With the addition of additional fuel to waste gas

Note. Lower heat of combustion at 20, 2

1D

6.2

20.2

Table continuation

Content

e nitrogen oxides after the device, mg / nm

82.1

0.0

OfO

0j.0 of native gas 0. - 34828 kJ / nm,

Claims (1)

METHOD FOR EMERGENCYING EXHAUST GASES by oxidizing the toxic impurities contained in them while supplying additional gas generation of fuel and subsequent regenerative heating of the waste gases by the heat of the neutralization products, characterized in that, in order to reduce the formation of nitrogen oxides, additional gaseous fuel is introduced into the waste gas before the regenerative it is heated in a ratio of 6: 1000 to L3: 1000.