Combined soda calcining furnace gas recovery system

Abstract

The utility model provides a combined-soda calcining furnace gas recovery system. The combined-soda calcining furnace gas recovery system comprises a furnace gas filter, an inlet furnace gas separator, a compressor, a tail end furnace gas heat exchanger and a tail end furnace gas separator, the compressor is a centrifugal compressor, and a plurality of spraying water pipes leading to a bend between the first-stage impeller and the second-stage impeller are arranged on the circumference of a shell of the centrifugal compressor so as to spray water to cool gas compressed by the first-stage impeller. According to the combined-soda calcining furnace gas recovery system disclosed by the utility model, the gas compressed by the impeller is cooled by spraying water at the outlet curve, so that the problems of quicker and higher temperature rise in the furnace gas compression process are solved, the impeller is favorably cleaned, and the long-period, safe and stable operation of the system is ensured.

Description

TECHNICAL FIELD

[0001] The utility model belongs to soda ash chemical technology field, concretely relates to a kind of soda calcination furnace gas recovery system. BACKGROUND

[0002] The main components of soda calcination process furnace gas are carbon dioxide (85.3%), nitrogen (4.5%), water vapor (7.7%), and a small amount of oxygen, ammonia and alkali dust. The pressure is 0.095 MP(A) at normal pressure, and the temperature is 30 degrees. The recycling of calcination furnace gas requires the concentration of CO2 in the calcination furnace gas to reach 85% and be pressurized to 0.5 MPa for transportation to the caustic tower for utilization. The reciprocating compressor has always been the pressurizing equipment for the calcination furnace gas recovery and pressurization of the caustic industry. Due to the complex composition of the calcination furnace gas, which contains carbon dioxide and ammonia, the corrosion resistance and sealing requirements of the compressor are high. The reciprocating compressor pressurization process has not effectively solved the gas cleanliness, and there are problems such as scarring, dust carrying, crystallization, compression temperature rise, and high-speed vibration, which affect the long-term, safe and stable operation of the reciprocating compressor. The industry traditionally uses multiple reciprocating (or screw) compressor devices in parallel to solve the problem of high single-machine failure rate and affect long-term operation of the system. This not only occupies a large area, but also has high maintenance costs. SUMMARY

[0003] To solve the technical problems existing in the pressurization process of the soda calcination process furnace gas recovery of the prior art, the utility model provides a soda calcination furnace gas recovery system.

[0004] The soda calcination furnace gas recovery system comprises a furnace gas filter, an inlet furnace gas separator, a compressor, a terminal furnace gas heat exchanger and a terminal furnace gas separator arranged in sequence. The compressor is a centrifugal compressor, and the circumference of the shell of the centrifugal compressor is provided with a plurality of spray water pipes leading to the bend between the primary impeller and the secondary impeller to spray water to cool the gas compressed by the primary impeller and facilitate the cleaning of the secondary impeller, thereby ensuring the long-term stable operation of the centrifugal compressor.

[0005] The centrifugal compressor is a two-stage centrifugal compressor. The furnace gas compressed by the primary impeller and the secondary impeller of the first stage is discharged from the first-stage gas outlet and enters the second-stage gas inlet. After being compressed by the primary impeller and the secondary impeller of the second stage, the furnace gas is discharged from the second-stage gas outlet and enters the terminal furnace gas heat exchanger.

[0006] A stage-to-stage furnace gas heat exchanger and a stage-to-stage furnace gas separator are arranged between the first-stage gas outlet and the second-stage gas inlet.

[0007] The centrifugal compressor is driven by a steam turbine or a variable frequency motor.

[0008] The soda ash calcination furnace gas recovery system described in this utility model solves the problems of rapid and high temperature rise during furnace gas compression by spraying water to cool the gas after it has been compressed by the impeller at its outlet bend, and also facilitates impeller cleaning. Furthermore, by installing a furnace gas filter, furnace gas separator, and furnace gas heat exchanger, the system improves the cleanliness of the furnace gas and reduces its temperature, ensuring long-term, safe, and stable operation. The use of a two-stage centrifugal compressor saves investment and reduces floor space and operating costs. Attached Figure Description

[0009] Figure 1 This is a schematic diagram of the structure of an embodiment of the present utility model;

[0010] Figure 2 This is a schematic diagram of the two-stage centrifugal compressor structure in the embodiment. Detailed Implementation

[0011] The specific embodiments of this utility model will be further described below with reference to the accompanying drawings:

[0012] like Figure 1 , Figure 2 As shown, the soda ash calcination furnace gas recovery system of this utility model includes a furnace gas filter 101, an inlet furnace gas separator 102, a two-stage centrifugal compressor 1 driven by a steam turbine 103, an end furnace gas heat exchanger 106, and an end furnace gas separator 107 arranged in this manner. Multiple spray water pipes 15 are arranged around the circumference of the casing 3 of the centrifugal compressor 1, leading to the bend 4 between the first-stage and second-stage impellers, to spray water to cool the gas compressed by the first-stage impeller. After being compressed by the first-stage impeller 13 and the first-stage second-stage impeller 14, the furnace gas is discharged from the first-stage gas outlet 12, cooled by the inter-stage furnace gas heat exchanger 104, purified by the inter-stage furnace gas separator 105, and enters the second-stage gas inlet 21. After being compressed by the second-stage first-stage impeller 23 and the second-stage second-stage impeller 24, it is discharged from the second-stage gas outlet 22 and enters the end furnace gas heat exchanger 107.

[0013] The utility model discloses a kind of associated alkali calcination furnace gas recovery systems, when running, calcination furnace gas is first filtered 101 into inlet furnace gas separator 102;Then enter compressor first stage first-stage impeller 13 by centrifugal compressor 1 one-stage gas inlet 11, after gas pressurization exits first-stage impeller 13, spray water pipe 15 atomization water spray cooling washing, enter second-stage impeller 14 pressurization after first stage from one-stage gas outlet 12 discharge centrifugal compressor 1, temperature is about 135 °, enter section furnace gas heat exchanger 104 cooling down.Then enter section furnace gas separator 105, (containing ammonia, containing dust waste water recovery treatment), after cooling and purification gas enters compressor second stage gas inlet 21, temperature 30 degrees, pressure 0.3MPa, enter compressor second stage first-stage impeller 23, after gas pressurization exits second-stage impeller 23, spray water pipe 15 atomization water spray cooling washing, enter second-stage impeller 24 pressurization after second-stage gas outlet 22 discharge centrifugal compressor 1, temperature is about 130 ° enter end furnace gas heat exchanger 106 cooling down, then into end furnace gas separator 107, (containing ammonia, containing dust waste water recovery treatment), pressure is boosted to 0.62MPa, after cooling and purification furnace gas enters associated alkali carbonation process utilization.Furnace gas filter 101 is provided with differential pressure sensor, system can be automatically water-washing calcination furnace gas filter 101 according to pressure difference;Section furnace gas heat exchanger 104 and end furnace gas heat exchanger 106 import and export are provided with differential pressure sensor, measure and track import and export pressure difference, there is automatic water-washing device according to pressure difference value in furnace gas heat exchanger import, realize to the automatic cleaning of furnace gas heat exchanger pipeline, control scab, block pipe, to guarantee the long period, safe, stable operation of system.

Claims

1. A combined-soda calciner off-gas recovery system comprising, in this order, an off-gas filter, an inlet off-gas separator, a compressor, a final off-gas heat exchanger, and a final off-gas separator; characterized in that The compressor is a centrifugal compressor, and a plurality of spray water pipes are arranged on the circumference of the shell of the centrifugal compressor and lead to the bend between the primary impeller and the secondary impeller, so as to spray water to cool the gas compressed by the primary impeller.

2. A combined alkali calciner off-gas recovery system according to claim 1, characterized in that The centrifugal compressor is a two-stage centrifugal compressor, and the furnace gas compressed by the primary impeller and the secondary impeller of the first stage is discharged from the gas outlet of the first stage, enters the gas inlet of the second stage, is compressed by the primary impeller and the secondary impeller of the second stage, is discharged from the gas outlet of the second stage, and enters the end furnace gas heat exchanger.

3. A combined alkali calciner off-gas recovery system according to claim 2, characterized in that The inter-stage furnace gas heat exchanger and the inter-stage furnace gas separator are arranged between the gas outlet of the first stage and the gas inlet of the second stage.

4. A combined alkali calciner off-gas recovery system according to claim 1, characterized in that The centrifugal compressor is driven by a steam turbine or a variable frequency motor.

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