RU1820854C - Process of purifying steam-and-gas mixture - Google Patents

Abstract

Usage: to remove harmful emissions in the metallurgical industry. chemical and petrochemical industries. The essence of the invention is that in the cleaning method, which involves aspirating a vapor-gas mixture from a volume, converting it into fog by supplying a cooling gas with a temperature lower than the temperature of the vapor-gas mixture to the vapor-gas mixture. Surface condensation of steam and condensate separation, a part of the vapor-gas mixture is used as cooling gas , which is taken after the surface condensation zone is additionally cooled and fed into the steam-gas mixture stream before the surface condensation zone, while with the flow of cooling gas in the vapor-gas mixture additionally serves solid particles and / or drops of liquid with a temperature not higher than the temperature of the cooling gas. 1 C.p. f-ls, t ill.

Description

The invention relates to metallurgy, in particular to the removal of harmful emissions from continuous casting of steel.

 The purpose of the method is to eliminate these drawbacks, increase the efficiency of condensation and reduce emissions of harmful substances into the atmosphere, reduce the temperature of the emitted vapor-gas mixture.

The drawing shows a device for implementing the proposed method, consisting of a hopper 1, a pipe 2, a smoke exhauster 3, a gas supply device 4, a device for supplying solid particles and / or liquid droplets 5, a flow swirl 6, a heat exchanger 7, a condensate collector 8. From the hopper 1 a gas-vapor mixture (ASG) is sucked off through line 2 by a smoke exhaust fan 3. Device 4. made in the form of a fan, gas is supplied to the ASG with a temperature below the ASG temperature. Together with the gas stream of device 5, solid particles and / or liquid droplets are additionally supplied to the ASG with a temperature not exceeding the ASG temperature after mixing with the gas. The fog resulting from the mixing of ASG and gas is twisted relative to its axis of motion by flow swirl 6. The swirling ASG enters the heat exchanger 7, where surface steam condensation occurs. As a result of the swirling of the flow, centrifugal forces act on the condensate droplets of the mist formed, under the influence of which the condensate droplets are separated from the volume deposited on the walls of the pipeline 2 and the heat exchanger 7, and together with the condensate,

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formed as a result of surface condensation, drain into the condensate collector 8. The smoke exhauster 3 left with the mixture is discharged into the atmosphere.

The proposed method for removing ASG is implemented as follows.

ASG is sucked out of the hopper of the secondary cooling zone M.NLZ using a D-15.5 smoke exhauster in an amount of 89,000 m3 / h at a temperature of 80 ° C. The condensate flow rate during natural condensation of water vapor on the walls of the pipeline was 0.04 g / s. In addition, the ASG passed through a surface condenser with a heat transfer area of 20 m and a flow rate of cooling water of 3 m3 / h. The condensate yield during condensation on the surface of the condenser was 0.365 kg / s. The limits of the amount of gas supply to the ASG were determined as n 0.1-0.3 of the initial ASG consumption.

EXAMPLE 1. After exhausting the ASG from the hopper, gas was supplied to it with a flow rate of-0.2 from the initial ASG flow rate, which is 16000 m3 / h at 25 ° C. When ASG and gas were mixed, fogging occurred. The resulting mist was twisted relative to its axis of motion by a four-blade air swirl, and due to the action of condensate drops. In the flow of the mixture of CWG and centrifugal force gas, condensate droplets were separated on the walls of the pipeline and condenser. The increase in condensate yield was 0.1 g / s or 33% of the initial condensate output.

Then, additional drops of liquid (water) 0.5 mm, with a flow rate of 0.03 kg / s at 20 ° С, were additionally supplied to the ASG together with gas flows. The increase in the condensate yield in this case was 0.15 g / s or 50% of the initial condensate outlet.

After the condensate droplets were separated from the flow, a part of the dried ASG with a flow rate of 16,000 m3 / h was taken from the main path of the ASG removal system using a fan of brand C 4-70 No. 6 and additionally passed through an air cooler, where it was cooled to 25 ° C and then fed through a pipeline recycling systems to the main path of the gas removal system of the ASG.

As a result, the total condensate flow rate was 0.455 g / s or 1.5 times more than the initial condensate flow rate.

Thus, the concentration of harmful substances. dissolved in the condensate, did not change, a decrease in emissions of harmful substances into the atmosphere was due to an increase in

condensate outlet with harmful substances dissolved in it. The temperature of ASG emitted into the atmosphere decreased to 42 ° C.

Example. In accordance with the initial data of example 1, when gas was supplied to the ASG with a boundary flow rate of 0.1 at the initial flow rate of the ORG or 8000 m3 / h, fogging occurred and the increase in condensate yield was 0.07 kg / s or 23% of the initial output condensate.

When gas was supplied to an ASG with a second boundary flow rate of 0.3 p from the initial flow rate of the CWG or 24,000 m3 / h, the increase in the condensate output was 0.13 g / s or 43% of the initial condensate output.

Example 3. In accordance with the initial data of example 1, when supplying gas to the CWG beyond the limits (0.1-0.3), i.e. with a flow rate of 0.05 from the initial PPGS flow rate or 4000 m3 / h, fogging did not occur.

When gas was supplied to the ASG with a flow rate of 0.4 of the initial ASG flow rate or 32,000 m3 / h, the condensate growth was 0.135 e g / s, i.e. the condensate yield was practically unchanged compared to example 2, with a significant increase in energy consumption for gas supply. .

Using the proposed method for removing ASG provides, in comparison with existing methods, the following advantages:

increased condensate yield.

in addition, due to an increase in the yield of condensate, the amount of substances dissolved in the condensate and the trapped dust increases, and, consequently, the emission of harmful substances into the atmosphere is reduced.

in addition, by supplying cooled gas to the ASG and cooling the ASG at the surface condenser, the temperature of the exhausted ASG is reduced.

Formula Mule Found

Claims (2)

1. A method of purifying a gas-vapor mixture, including suctioning the gas-vapor mixture from the volume, converting it into fog by supplying cooling gas at a temperature lower than the temperature of the gas-vapor mixture to the gas-vapor mixture, surface condensation of the vapor and condensate separation, so that, in order to to increase the efficiency of condensation and reduce emissions of harmful substances into the atmosphere, a part of the gas-vapor mixture is used as cooling gas, which is taken after the surface condensation zone, additionally cooled and fed to gas-vapor mixture stream in front of the surface condensation zone. 2. A method according to claim t, characterized in that, in addition to the flow of cooling gas into the Iarogas mixture, solid particles and / or liquid droplets with a temperature not exceeding the temperature of the cooling gas are supplied. MS - / 7