Pre-concentrator for hydrochloric acid regeneration

Abstract

The utility model relates to a preconcentrator for hydrochloric acid regeneration, which comprises a concentration section, a cooling filter section and a gas-liquid separation section, the concentration section is provided with a concentration tower, the gas-liquid separation section is provided with a gas-liquid separation cylinder, and the cooling filter section is provided with a cooling filter tank; the upper part of the contraction section, the throat pipe section and the expansion section of the concentration tower sequentially comprise a silicon carbide layer, an acid-resistant ceramic tile layer and a high-strength steel layer from inside to outside; the cooling filter tank comprises a tank body, a filter cartridge, a heat exchange tube, a liquid outlet and a liquid inlet, the heat exchange tube is wound on the outer wall of the tank body, cooling water is introduced into the heat exchange tube, the filter cartridge is arranged in the tank body, the liquid outlet is connected to the bottom of the tank body, the liquid outlet is connected with the gas-liquid separation cylinder, the liquid inlet is formed above the filter cartridge, and the liquid inlet is connected with the concentration tower. The device has the advantages that the cooling and filtering section is arranged, so that the temperature of the HCI-containing high-temperature flue gas is reduced to below 100 DEG C, and heat energy is recycled by using cooling water. The temperature gradient inside and outside the concentrating tower is increased at the throat section, and the service life of the throat section is prolonged.

Description

TECHNICAL FIELD

[0001] The utility model belongs to pickling waste liquid regeneration field especially relates to a kind of for hydrochloric acid regeneration pre-concentrator. BACKGROUND

[0002] In the cold rolling process of steel industry, the surface of metal is often pickled by hydrochloric acid to remove the surface scale, and a large amount of pickling waste liquid containing ferrous chloride is produced, Fe 2+ In the cold rolling process of steel industry, the surface of metal is often pickled by hydrochloric acid to remove the surface scale, and a large amount of pickling waste liquid containing ferrous chloride is produced, Fe

[0003] The more mature treatment technology is roasting method, that is, the pickling waste liquid is concentrated in the pre-concentrator, and the concentrated liquid enters the acid regeneration roasting furnace for high-temperature decomposition, and the ferrous chloride is decomposed into red iron oxide, which is a high-quality raw material for magnetic oxide and is sold on the market. The high-temperature flue gas containing HCl generated by high-temperature decomposition enters the pre-concentrator to contact with the pickling waste liquid, so that the temperature of the high-temperature flue gas is reduced to 90-95℃, and the pickling waste liquid is concentrated to 75% of the original volume. The concentrated pickling waste liquid enters the roasting furnace for high-temperature decomposition.

[0004] The pre-concentrator is very important in the whole roasting system, which has the functions of cooling, dust removal and solution concentration. In actual production, due to the high temperature and complex operation of the pre-concentrator, the gas after gas-liquid separation will carry a part of liquid droplets, and the liquid droplets will enter the subsequent hydrochloric acid absorption tower with the gas, and then enter the regenerated acid after being absorbed by water, so that the regenerated acid contains 3-5g / L of iron ions, making the regenerated acid appear light red, which can only be recycled in the pickling process and has lower pickling efficiency than fresh hydrochloric acid. The pre-concentrator mainly uses the flue gas cooling system to reduce the temperature of the high-temperature flue gas containing HCl to below 100℃, which increases the cooling cost. In addition, the temperature of the middle throat pipe section of the pre-concentrator is very high, and the high-temperature flue gas has strong scouring force at this position, which causes strong acid corrosion and affects the service life. SUMMARY

[0005] The utility model aims at providing a kind of for hydrochloric acid regeneration pre-concentrator, reduce pre-concentrator cooling cost, improve the temperature resistance and acid resistance of throat pipe section, improve service life.

[0006] To achieve the above object, the utility model realizes by the following technical scheme:

[0007] A kind of for hydrochloric acid regeneration pre-concentrator, including concentration section, cooling filter section, gas-liquid separation section, concentration section is equipped with concentration tower, gas-liquid separation section is equipped with gas-liquid separation cylinder, cooling filter section is equipped with cooling filter tank;

[0008] The concentration tower comprises, from bottom to top, a contraction section, a throat section and an expansion section, the upper part of the contraction section, the throat section and the expansion section comprise, from inside to outside, a silicon carbide layer, an acid-resistant tile layer and a high-strength steel layer, and the throat section is provided with a dust removal grid; the lower part of the contraction section is connected with a concentrated gas outlet pipe and a concentrated liquid outlet pipe;

[0009] The cooling filter tank comprises a tank body, a filter cartridge, a heat exchange pipe, a liquid outlet, and a liquid inlet.

[0010] The bottom of the tank body is connected with a waste discharge port, and the bottom of the filter cartridge is in a conical structure.

[0011] The bottom of the filter cartridge is in a filter screen structure.

[0012] The material of the filter cartridge is PPH or PVDF.

[0013] The liquid inlet and the concentrated liquid outlet pipe of the concentration tower are connected through a connecting pipeline.

[0014] The connecting pipeline is externally provided with a cooling cavity, and the cooling cavity is connected with a water inlet and a water outlet.

[0015] The water inlet is connected with the heat exchange pipe.

[0016] The gas-liquid separation cylinder comprises a straight cylinder at the upper part and a conical cylinder at the lower part, the top of the straight cylinder is provided with a gas outlet, and the bottom of the conical cylinder is provided with a concentrated liquid outlet; the side of the conical cylinder is connected with a liquid inlet, and the liquid inlet is connected with the liquid outlet of the cooling filter tank through a pipeline; the side of the straight cylinder is connected with a gas inlet, and the middle of the straight cylinder is coaxially provided with a gas flow guide cylinder and a multi-stage liquid removal cylinder from the center to the outside; the side of the multi-stage liquid removal cylinder, which faces the gas connecting pipeline inlet, is in an open structure.

[0017] The multi-stage liquid removal cylinder is a three-stage liquid removal cylinder, which comprises a first-stage liquid removal cylinder, a second-stage liquid removal cylinder and a third-stage liquid removal cylinder arranged from inside to outside.

[0018] Compared with the prior art, the cooling filter tank has the following beneficial effects:

[0019] 1. The temperature-resistant and acid-resistant structure is adopted in the upper part of the contraction section, the throat section and the expansion section of the concentration tower, so that the temperature gradient inside and outside the concentration tower is increased, the external temperature is low, the normal work of the equipment is ensured, energy is saved, and the service life of the throat section is prolonged.

[0020] 2. The cooling filter section is arranged between the concentration section and the gas-liquid separation section, so that the temperature of the high-temperature HCI-containing flue gas is reduced to below 100 DEG C, and the cooling water is used to recover heat energy, thereby saving investment. The cooling cavity is arranged outside the connecting pipeline to cool the connecting pipeline, and the cooling water can be provided by the cooling water flowing through the heat exchange pipe, thereby forming gradient cooling and saving the cost of laying the external pipeline.

[0021] 3. The gas guide cylinder and the multi-stage liquid removal cylinder are arranged in the gas-liquid separation cylinder, so that the gas forms multi-stage cyclone after entering, thereby greatly reducing the amount of pickling waste liquid entrained by the gas at the outlet of the gas-liquid separation section, greatly reducing the content of iron ions in the hydrochloric acid produced by the hydrochloric acid absorption tower, and improving the quality of the regenerated acid. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is a structural schematic view of the concentration section.

[0023] Figure 2 is a structural schematic view of the cooling filter section and the gas-liquid separation cylinder.

[0024] Figure 3 is Figure 2 is a sectional view along the line A-A.

[0025] Figure 4 is a structural schematic view of the connecting pipeline.

[0026] In the figure: 1 - high-temperature flue gas inlet; 2 - pickling waste liquid inlet; 3 - expansion section; 4 - throat section; 5 - dust removal grid plate; 6 - contraction section; 7 - concentrated gas outlet pipe; 8 - concentrated liquid outlet pipe; 9 - silicon carbide layer; 10 - acid-resistant porcelain tile layer; 11 - heat exchange pipe; 12 - filter cylinder; 13 - liquid outlet; 14 - liquid inlet; 15 - gas inlet; 16 - gas guide cylinder; 17 - first-stage liquid removal cylinder; 18 - second-stage liquid removal cylinder; 19 - third-stage liquid removal cylinder; 20 - connecting pipeline; 21 - cooling cavity; 22 - water outlet; 23 - water inlet. DETAILED DESCRIPTION

[0027] The utility model will be described in detail below in combination with the drawings of the specification, but it should be pointed out that the implementation of the utility model is not limited to the following embodiments.

[0028] Example 1

[0029] See Figures 1-3The application relates to a pre-concentrator for hydrochloric acid regeneration, which comprises a concentration section, a cooling and filtering section and a gas-liquid separation section, wherein the concentration section is provided with a concentration tower, the gas-liquid separation section is provided with a gas-liquid separation cylinder, and the cooling and filtering section is provided with a cooling and filtering tank. The concentration tower comprises a contraction section 6, a throat section 4 and an expansion section 3 from bottom to top, and the upper part of the contraction section 6, the throat section 4 and the expansion section 3 comprise a silicon carbide layer 9, an acid-resistant porcelain tile layer 10 and a high-strength steel layer from inside to outside, so that the temperature gradient inside and outside the pre-concentrator is increased, the normal working of the concentration tower is ensured, and energy is saved. A dust removal grid is arranged in the throat section 4; the lower part of the contraction section 6 is connected with a concentrated gas outlet pipe 7 and a concentrated liquid outlet pipe 8. The silicon carbide layer 9 is formed by silicon carbide bricks, the acid-resistant porcelain tile layer 10 is formed by acid-resistant porcelain tiles, the outer high-strength steel layer is a shell and is made of high-strength steel plates. Acid-resistant fiber materials are filled between the high-strength steel layer and the acid-resistant porcelain tile layer 10, so that corrosion and heat insulation are realized.

[0030] The cooling and filtering tank comprises a tank body, a filtering cylinder 12, heat exchange pipes 11, a liquid outlet 13 and a liquid inlet 14. The tank body is wrapped with the heat exchange pipes 11, cooling water is circulated in the heat exchange pipes 11 to cool the liquid entering the cooling and filtering tank. The filtering cylinder 12 is arranged in the tank body, the liquid outlet 13 is arranged at the bottom of the tank body, and the liquid in the tank body is filtered and discharged through the liquid outlet 13. The liquid outlet 13 is connected with the gas-liquid separation cylinder through a pipeline, and the liquid inlet 14 is arranged at the top of the tank body and above the filtering cylinder 12. The liquid inlet 14 is connected with the concentrated liquid outlet pipe 8 of the concentration tower.

[0031] The tank body is connected with a waste discharge port, the bottom of the filtering cylinder 12 is in a conical structure, the bottom of the conical structure is connected with the waste discharge port, and the impurities filtered by the filtering cylinder 12 are discharged through the waste discharge port. The bottom of the filtering cylinder 12 is in a filter screen structure. The filtering cylinder 12 can be taken out from the top of the tank body for cleaning at regular time intervals. The filtering cylinder 12 is made of PPH or PVDF to avoid corrosion of the acid liquid.

[0032] See Figure 2 , Figure 4 The liquid inlet 14 is connected with the concentrated liquid outlet pipe 8 of the concentration tower through a connecting pipeline 20. The connecting pipeline 20 is externally provided with a cooling cavity 21, the cooling cavity 21 is connected with a water inlet 23 and a water outlet 22. Cooling water is circulated in the cooling cavity 21 to cool the liquid in the connecting pipeline 20. The water inlet 23 is connected with the heat exchange pipes 11.

[0033] Working principle: high temperature flue gas from the top of the concentration tower high temperature flue gas inlet 1, pickling waste liquid by the top pickling waste liquid inlet 2, through the dust grid downward, gas by concentration gas outlet pipe 7 is discharged, to the gas-liquid separation section, the liquid droplets in the gas is separated out. Concentrated liquid by concentrated liquid outlet pipe 8 is discharged, through the connecting pipe 20 cooling, into the cooling filter tank, cooling and filtering in the filter tank, remove impurities, and make the concentration of liquid temperature to below 100 DEG C. The filtered concentrated liquid is sent to the gas-liquid separation cylinder, and the liquid droplets separated from the concentrated gas are combined and sent to the calcination furnace. The concentrated gas separated by the gas-liquid separation cylinder is sent to the absorption tower.

[0034] Example 2

[0035] See Figures 1-3 , on the basis of example 1, the gas-liquid separation cylinder is composed of an upper straight cylinder and a lower conical cylinder, the top of the straight cylinder is provided with a gas outlet, the bottom of the conical cylinder is provided with a concentrated liquid outlet, the side of the conical cylinder is connected with a liquid inlet, the liquid inlet is connected with the liquid outlet 13 of the cooling filter tank through a pipeline, the side of the straight cylinder is connected with a gas inlet 15, the middle part of the straight cylinder is coaxially provided with a gas flow guide cylinder 16 and a multi-stage liquid removal cylinder from the center to the outside, the side of the multi-stage liquid removal cylinder facing the inlet of the pipeline 20 is of open structure. The multi-stage liquid removal cylinder is a three-stage liquid removal cylinder, which is composed of a first-stage liquid removal cylinder 17, a second-stage liquid removal cylinder 18 and a third-stage liquid removal cylinder 19 arranged from inside to outside.

[0036] After the concentrated gas enters the gas-liquid separation cylinder, it is divided by the three-stage liquid removal cylinder and the gas flow guide cylinder 16, and rotates at high speed in the multi-layer annular gap formed by the three-stage liquid removal cylinder and the gas flow guide cylinder 16, the liquid droplets in the concentrated gas are thrown to the corresponding cylinder wall and flow downward along the cylinder wall to the bottom of the gas-liquid separation cylinder, and then are sent to the calcination furnace after being combined with the concentrated liquid.

[0037] The utility model adopts temperature-resistant and acid-resistant structure in the contraction section 6 of the concentration tower, the throat pipe section 4 and the expansion section 3, increases the temperature gradient inside and outside the concentration tower, the outside temperature is low, ensures the normal work of equipment, saves energy, prolongs the service life of the throat pipe section 4. The cooling filter section is directly arranged between the concentration section and the gas-liquid separation section, the temperature of the high-temperature flue gas containing HCl is reduced to below 100 DEG C, and the cooling water is used to recover heat energy, which saves investment.

Claims

1. A pre-concentrator for hydrochloric acid regeneration, characterized by, The device comprises a concentration section, a cooling and filtering section and a gas-liquid separation section, the concentration section is provided with a concentration tower, the gas-liquid separation section is provided with a gas-liquid separation cylinder, and the cooling and filtering section is provided with a cooling and filtering tank; The concentration tower comprises a contraction section, a throat section and an expansion section from bottom to top, and the upper part of the contraction section, the throat section and the expansion section comprise a silicon carbide layer, an acid-resistant tile layer and a high-strength steel layer from inside to outside, and the throat section is provided with a dust removal grid; The cooling and filtering tank comprises a tank body, a filter cylinder, a heat exchange pipe, a liquid outlet and a liquid inlet, the tank body is provided with the heat exchange pipe, the filter cylinder is arranged in the tank body, the liquid outlet is connected to the bottom of the tank body and connected to the gas-liquid separation cylinder through a pipeline, and the liquid inlet is connected to the top of the tank body and arranged above the filter cylinder and connected to the concentrated liquid outlet pipe of the concentration tower.

2. A pre-concentrator for hydrochloric acid regeneration according to claim 1, characterized in that, The bottom of the tank body is connected with a waste discharge port, the bottom of the filter cylinder is in a conical structure, and the bottom of the conical structure is connected with the waste discharge port.

3. A pre-concentrator for hydrochloric acid regeneration as claimed in claim 1, wherein, The bottom of the filter cylinder is in a filter screen structure.

4. A pre-concentrator for hydrochloric acid regeneration as claimed in claim 1, wherein, The material of the filter cylinder is PPH or PVDF.

5. A pre-concentrator for hydrochloric acid regeneration as claimed in claim 1, wherein, The liquid inlet and the concentrated liquid outlet pipe of the concentration tower are connected through a connecting pipeline.

6. A pre-concentrator for hydrochloric acid regeneration according to claim 5, characterized in that, The connecting pipeline is provided with a cooling cavity outside, and the cooling cavity is connected with a water inlet and a water outlet.

7. A pre-concentrator for hydrochloric acid regeneration according to claim 6, characterized in that, The water inlet is connected with the heat exchange pipe.

8. A pre-concentrator for hydrochloric acid regeneration as claimed in claim 1, wherein, The gas-liquid separation cylinder comprises a straight cylinder at the upper part and a conical cylinder at the lower part, the top of the straight cylinder is provided with a gas outlet, the bottom of the conical cylinder is provided with a concentrated liquid outlet, the side of the conical cylinder is connected with a liquid inlet, the liquid inlet is connected to the liquid outlet of the cooling and filtering tank through a pipeline, the side of the straight cylinder is connected with a gas inlet, the middle of the straight cylinder is provided with a gas flow guide cylinder and a multi-stage liquid removal cylinder coaxially from the center to the outside, and the side of the multi-stage liquid removal cylinder facing the inlet of the gas connecting pipeline is in an open structure.

9. A pre-concentrator for hydrogen chloride regeneration according to claim 8, characterized in that, The multi-stage liquid removal cylinder is a three-stage liquid removal cylinder, which comprises a first-stage liquid removal cylinder, a second-stage liquid removal cylinder and a third-stage liquid removal cylinder arranged from inside to outside.

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