SU1699551A1 - Method of separating sulfur dioxide and alkaline cement dust from effluent gases - Google Patents

Abstract

The invention relates to the technology of cleaning the exhaust gases of rotary kilns of cement production from SO, and alkaline cement dust, which allows to increase the degree of purification from 50. The specified exhaust gases are fed to trapping coarse dust to obtain the molar ratio of alkaline components contained in the exhaust gases in the composition of dust and SOZ, equal to 2: 1. Then, fine dust is collected and 80 g of alkaline cement dust are simultaneously neutralized in a reactor with a nozzle at 180–200 ° C and a gas flow rate (6–8) 103. The entire waste gas stream is fed to the reactor and water vapor is supplied to the nozzle zone in the amount of 3-5% of the volume of gas being purified. The degree of gas purification is from 50 to 90-97%, the dust content of the gases at the exit is 33-90 mg / m3. 1 il. 2 tab. with SS (L

Description

The invention relates to the purification of industrial gases from harmful impurities and may find application in the production of cement.

The aim of the invention is to increase the degree of purification from sulfur dioxide.

The drawing shows a diagram of the method.

The exhaust gases of the rotary kiln 1 containing solid and toxic gaseous impurities enter the first purification stage, for example, a two-floor electrostatic precipitator 2. The large dust particles collected by the electrostatic precipitator 2 are removed and returned to the cement production process, and the exhaust gases after containing small-. Persistent high-alkaline dust and gaseous toxic components (50) in a 2: 1 ratio are fed to the second purification stage in the reactor 3 of the packing type. Raschig rings, glass balls, etc. can be used as the nozzle 4. When gas is passed through the reactor 3, alkaline fine dust is deposited on the nozzle 4, forming a developed contact surface. The acidic component of the waste gases, sulfur dioxide, interacts with the alkaline components of the settled dust, resulting in its chemical bonding to form sulfites and sulfates. The temperature of the gases in the reactor is maintained at 180-200 C. The volumetric gas velocity is (, 0) -103. In order to intensify the process of trapping S02

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Steam in the amount of 3-5% of the volume of gas to be purified is supplied to the nozzle 4 of the reactor 3. The gases and gases cleaned in the reactor 3 from the dust and sulfur dioxide by the fan 5 are discharged to the atmosphere through the chimney 6. As the dust layer accumulates on the nozzle 4, the hydraulic resistance of the apparatus increases. When the hydraulic resistance of the permissible level is reached (about 2000 Pa), the nozzle 4 is regenerated. The regeneration is carried out by the method of reverse purging with the purified gas directed to the reactor 3 by the fan 7. The dust-air mixture resulting from the purge is directed to the cyclone 8. In the cyclone 8 worked10

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capacity with respect to sulfur dioxide. At the same time, the dust content of the exhaust gases is sharply reduced. At the same time, the reactor nozzle and the sorbent absorber (fine alkaline dust) remain dry during the whole operation time of the apparatus. The proposed method, in comparison with the known, allows to increase the degree of purification of gases from SO2 to 90-97% against 30% due to the fact that neutralization of acidic components is carried out in the whole stream of exhaust gases, and not in their part.

Claims (1)

Claim Method A method for removing sulfur dioxide and  absorber (high alkaline dust) 2p Chain cement dust from waste is deposited and removed, and the purified air stream passes through reactor 3 and is emitted into the atmosphere. The results are presented in Table. 1 and 2. An analysis of the results shows that the highest degree of S0a capture at a simultaneous dust content in the purified gases (at the reactor exit) of no more than 100 mg / m3 is achieved at: the molar ratio of the alkaline components to sulfur dioxide in the waste gases after the first cleaning stage 2: 1, the temperature in the reactor is 180–200 ° C and the gas flow rate (6.0– 8.0) .10 h (. The supply of water vapor to the nozzle zone in the amount of 3-5% of the volume of the gas to be purified promotes hydration of the alkaline components contained in the gas being purified to KOH, NaOH, Ca (OH) 2 {Mg (OH), which improves their reaction25 thirty 35 40 gases of rotary kilns of cement production, including trapping coarse and then fine dust and neutralizing sulfur dioxide with alkaline cement dust in a reactor, characterized in that, in order to increase the degree of purification from sulfur dioxide, trapping coarse dust leads to obtaining a molar ratio of alkaline components containing in the exhaust gases in the composition of dust and sulfur dioxide, equal to 2: 1, the collection of fine dust is combined with the stage of neutralization of sulfur dioxide of the entire flow of waste gases, while using a reactor with a nozzle, water vapor is supplied to the nozzle zone in an amount of 3-5% of the volume of gas being purified, the temperature in the reactor is maintained within 180–200 ° C with a gas-volume velocity of the gas in the reactor equal to (6–8 ). Y3 h five capacity with respect to sulfur dioxide. At the same time, the dust content of the exhaust gases is sharply reduced. At the same time, the reactor nozzle and the sorbent absorber (fine alkaline dust) remain dry during the whole operation time of the apparatus. The proposed method, in comparison with the known, allows to increase the degree of purification of gases from SO2 to 90-97% against 30% due to the fact that neutralization of acidic components is carried out in the whole stream of exhaust gases, and not in their part. Claim Method A method for removing sulfur dioxide and Chain cement dust from waste gases of rotary kilns of cement production, including trapping coarse and then fine dust and neutralizing sulfur dioxide with alkaline cement dust in a reactor, characterized in that, in order to increase the degree of purification from sulfur dioxide, trapping coarse dust leads to obtaining a molar ratio of alkaline components containing in the exhaust gases in the composition of dust and sulfur dioxide, equal to 2: 1, the collection of fine dust is combined with the stage of neutralization of sulfur dioxide in the whole stream; their gases, while using a reactor with a nozzle, water vapor is supplied to the nozzle zone in an amount of 3-5% of the volume of gas being purified, the temperature in the reactor is maintained within 180-200 ° C with a gas volume velocity in the reactor equal to (6- eight). Y3 h Table 1 The tests were carried out at a ratio of alkaline-containing components to S02 2: 1, at 200 ° C. CNJ S