Acid regeneration separation tank

Abstract

The utility model discloses an acid regeneration separation tank which comprises a tank body, a plurality of PVDF (Polyvinylidene Fluoride) reinforcing rings are sleeved outside a PVDF lining of the tank body, the PVDF reinforcing rings are fixed on the outer wall of the PVDF lining at intervals from top to bottom, and an FRP (Fiber Reinforce Plastic) outer coating layer of the tank body is simultaneously adhered and coated outside the PVDF lining and the PVDF reinforcing rings; a tangential air inlet is formed in the side wall of the tank body, an air outlet is formed in the top of the tank body, a liquid outlet is formed in the bottom of the tank body, a PVDF filter vat is fixed at the liquid outlet, the top and the bottom of the PVDF filter vat are open, the PVDF filter vat upwards extends into an inner cavity of the tank body through the liquid outlet, and the PVDF filter vat is fixed at the bottom of the tank body. A plurality of filtering holes for filtering blocky scaling substances are uniformly distributed in the side wall of the PVDF filtering barrel extending into the inner cavity of the tank body, and a heating mechanism for preventing the temperature of the tank body from being excessively reduced is also arranged on the tank body. The utility model has the advantage of long service life.

Description

Technical Field

[0001] The utility model relates to the technical field of hot-rolled steel coils, in particular to an acid regeneration separation tank. Background Art

[0002] A thermal annealing and pickling line (HAPL) is the first continuous process for heat treatment and pickling of hot-rolled coils. Acid regeneration in the HAPL occurs through roasting in a calciner, where the spent acid decomposes at high temperatures into gases and oxides. This converts the liquid into gas and solids, with the solid oxides falling to the furnace bottom. The generated gas, driven by a negative pressure blower, enters the acid regeneration pre-concentration system and scrubber for recovery.

[0003] Among them, the pre-concentration system is a very important link. The pre-concentration system generally includes a pre-concentrator and an acid regeneration separation tank. The outlet of the pre-concentrator is connected to the tangential air inlet of the acid regeneration separation tank, and the bottom outlet of the acid regeneration separation tank is connected to the side wall inlet of the pre-concentrator through a pre-concentration circulation pump. During operation, the high-temperature flue gas from the roasting furnace enters the pre-concentrator from the air inlet of the pre-concentrator. The high-temperature flue gas entering the pre-concentrator contacts the waste acid sprayed in the pre-concentrator for heat exchange, which reduces the high-temperature flue gas from 300°C to about 95°C and the waste acid temperature rises to about 90°C. At the same time, some iron oxide dust in the flue gas dissolves in the waste acid. In addition, the waste acid vaporizes at high temperature and enters the flue gas, so that the waste acid is concentrated. The concentrated waste acid and flue gas then enter the separation tank along the tangential direction. The liquid in the gas-liquid mixture from the pre-concentrator is separated to the bottom of the tank under the action of gravity. The gas with a small amount of liquid in the gas-liquid mixture from the pre-concentrator spirals up in the separation tank and enters the downstream scrubber from the top air outlet of the separation tank. If there is a lot of liquid dust in it, block-shaped scale will form on the wall of the separation tank. Under the action of gravity and slight negative pressure (-35mbar), it will fall off and enter the pre-concentration circulation pump, causing damage to the pre-concentration circulation pump and causing the system to fail to operate.

[0004] Furthermore, the acid regeneration separation tank currently in use is a composite tank composed of a PVDF (polyvinylidene fluoride) lining and an FRP outer covering via a special interface adhesive. The PVDF lining has a cylindrical upper portion and a conical lower portion. During shutdowns for maintenance, especially in winter, the linear expansion coefficient of PVDF is higher than that of FRP (130ppm / °C for PVDF and 11-35ppm / °C for epoxy fiberglass (FRP)). When the temperature inside the tank drops from 95°C to around 0°C, the radial contraction of PVDF is greater than that of FRP, generating additional tensile forces at the interface. After multiple shutdowns for maintenance, coupled with the gravity drop of scale deposits and the effects of slight negative pressure, the separation tank is prone to delamination and PVDF cracking, leading to damage. Utility Model Content

[0005] The utility model aims to provide an acid regeneration separation tank with a long service life.

[0006] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme: an acid regeneration separation tank, characterized in that: it comprises a tank body, a plurality of PVDF reinforcement rings are sleeved on the outside of the PVDF lining of the tank body, each PVDF reinforcement ring is fixed to the outer wall of the PVDF lining from top to bottom, and the FRP outer covering layer of the tank body is bonded and coated on the PVDF lining and the outside of each PVDF reinforcement ring; a tangential air inlet is provided on the side wall of the tank body, an air outlet is provided on the top of the tank body, a drain port is provided at the bottom of the tank body, a PVDF filter barrel is fixed at the drain port, the top and bottom of the PVDF filter barrel are open, the PVDF filter barrel extends upward into the tank body cavity through the drain port, and a plurality of filter holes for filtering block scales are evenly distributed on the side wall of the PVDF filter barrel extending into the tank body cavity, and a heating mechanism is also provided on the tank body to prevent the tank body from dropping too much in temperature.

[0007] Furthermore, in the aforementioned acid regeneration separation tank, the thickness of the PVDF lining of the tank body is 6 mm.

[0008] Furthermore, in the aforementioned acid regeneration separation tank, the structure of the heating mechanism includes: a steam port is provided on the side wall of the tank body, the steam port is provided with a steam valve connected to a steam source, and a temperature sensor is provided in the tank body for real-time monitoring of the internal temperature of the tank body, and the temperature sensor and the steam valve are simultaneously connected to the PLC controller signal.

[0009] Furthermore, in the aforementioned acid regeneration separation tank, a manhole for easy maintenance is provided on the side wall of the tank body, and a manhole cover for easy opening or closing of the manhole is provided at the manhole.

[0010] Furthermore, the aforementioned acid regeneration separation tank, wherein: a pre-separation tank is provided on the outside of the tank body, an inlet is provided on the top of the pre-separation tank, an overflow outlet is provided on the upper side wall of the pre-separation tank, a filter is provided at the overflow outlet, and the overflow outlet of the pre-separation tank is connected to the tangential air inlet on the side wall of the tank body through a connecting pipe.

[0011] Through the implementation of the above technical solutions, the beneficial effects of the utility model are as follows: (1) Changing the wall structure of the separation tank: a PVDF reinforcement ring is added to the PVDF lining, and is bonded and coated with FRP fiberglass together with the lining. When the machine is shut down and cooled, interlayer shear force will be generated between the PVDF reinforcement ring and the fiberglass coated thereon. Under the action of the interlayer shear force, the FRP outer coating will limit the thermal expansion of the PVDF lining and will not have a significant impact on the performance of the composite separation tank, thereby reducing the shrinkage and cracking of the PVDF lining caused by temperature drop; (2) The thickness of the PVDF lining is designed to be 6mm, which effectively increases the high-temperature creep resistance of the PVDF lining and further extends the service life of the separation tank; (3) A steam heating mechanism is added to prevent the tank body from stratification and PVDF cracking due to excessive temperature drop, further extending the service life of the separation tank; (4) A filtering structure is added to the bottom of the tank body. Through the structural design of the PVDF filter barrel, the block scale generated on the wall of the separation tank is effectively prevented from falling into the pre-concentration circulation pump, thereby preventing damage to the pre-concentration circulation pump and ensuring the orderly and smooth operation of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a structural schematic diagram of an acid regeneration separation tank described in the utility model.

[0013] Figure 2 for Figure 1 Top view of .

[0014] Figure 3 for Figure 2 AA section view shown in .

[0015] Figure 4 for Figure 2 BB cross-sectional view shown in .

[0016] Figure 5 for Figure 4 An enlarged schematic diagram of site C is shown in FIG.

[0017] Figure 6 This is a schematic diagram of the tank structure with the FRP outer covering layer hidden.

[0018] Figure 7 for Figure 1 Stereoscopic image.

[0019] Figure 8 This is a schematic diagram of the working principle of an acid regeneration separation tank described in the utility model. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is further described in detail below with reference to the accompanying drawings and embodiments.

[0021] like Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 、 Figure 7 、 Figure 8The PVDF lining 2 of the tank body 1 is provided with a plurality of PVDF reinforcing rings 3 on the outside, and each PVDF reinforcing ring 3 is fixed to the outer wall of the PVDF lining 2 from top to bottom. In this embodiment, the thickness of the PVDF lining of the tank body is 6 mm. This PVDF lining thickness design can effectively increase the high-temperature creep resistance of the PVDF lining, thereby preventing the tank body from delamination and the PVDF lining from cracking, and extending the service life of the separation tank; the FRP outer coating 4 of the tank body 1 is simultaneously bonded and coated on the outside of the PVDF lining 2 and each PVDF reinforcing ring 3; a tangential air inlet 5 is provided on the side wall of the tank body 1, and an air outlet 6 is provided on the top of the tank body 1. A drain port 7 is provided at the bottom of the tank 1, and a PVDF filter barrel 8 is fixed at the drain port 7. The outer peripheral wall of the PVDF filter barrel 8 is welded and sealed to the edge of the tank drain port 7; the top and bottom of the PVDF filter barrel 8 are open, and the PVDF filter barrel 8 extends upward into the tank body cavity through the drain port 7. A number of filter holes 9 for filtering block scales are evenly distributed on the side walls of the PVDF filter barrel 8 extending into the tank body cavity. A heating mechanism for preventing the tank body from dropping too much temperature is also provided on the tank body 1; in this embodiment, the structure of the heating mechanism includes: a steam port 10 is provided on the side wall of the tank body 1, and the steam port 10 is provided with a steam valve 12 connected to a steam source 11, and a device for real-time monitoring of the interior of the tank body is provided in the tank body 1. The temperature sensor 13, the temperature sensor 13 and the steam valve 12 are simultaneously connected to the PLC controller 14 signal; when the machine is shut down in winter, the temperature sensor 13 monitors the internal temperature of the tank in real time and feeds back to the PLC controller 14. When the PLC controller 14 determines and analyzes that the real-time temperature inside the tank is lower than the preset safety value, the PLC controller 14 controls to open the steam valve 12, so that the high-temperature steam of the steam source 11 enters the tank 1 from the steam valve 12 and the steam port 10, thereby heating the inside of the tank. When the internal temperature of the tank reaches the set value, the PLC controller 14 controls to close the steam valve 12, thereby avoiding excessive temperature drop of the separation tank when the machine is shut down; thereby reducing the PVDF lining caused by excessive temperature drop Shrinkage cracking can be prevented, thereby further extending the service life of the equipment. In this embodiment, a manhole 15 for easy maintenance is provided on the side wall of the tank body 1, and a manhole cover 16 for easy opening or closing the manhole 15 is provided at the manhole 15. During maintenance, the manhole cover 16 is opened, and workers can enter the tank body 1 from the manhole 15 to clean the block scale filtered by the PVDF filter barrel and retained in the tank body 1. In this embodiment, a pre-separation tank 17 is provided on the outside of the tank body 1, and an inlet 18 is provided on the top of the pre-separation tank 17. An overflow outlet is provided on the upper side wall of the pre-separation tank 17, and a filter screen 19 is provided at the overflow outlet. The overflow outlet of the pre-separation tank 17 is communicated with the tangential air inlet 5 on the side wall of the tank body 1 through a connecting pipe 20.

[0022] During operation, after the gas-liquid mixture discharged from the pre-concentrator 21 enters the pre-separation tank 17 from the top inlet 18 of the pre-separation tank 17, the gas-liquid mixture collides with the inner wall of the pre-separation tank 17, and the waste acid liquid in the gas-liquid mixture accumulates in the pre-separation tank 17, and the gas with a small amount of waste acid liquid in the gas-liquid mixture enters the tank body 1 from the filter screen 19 of the overflow outlet, thereby pre-separating the gas-liquid mixture, and the waste acid liquid in the gas-liquid mixture accumulates in the pre-separation tank 17. As the waste acid liquid increases, the waste acid liquid will also enter the tank body 1 through the filter screen 19 of the overflow outlet. After the waste acid liquid and gas are filtered by the filter screen 19, large particles of impurities will not enter the tank body 1, and then will not enter the pre-concentration circulation pump 22, which is conducive to smooth production.

[0023] After preliminary separation in the pre-separation tank 17, the concentrated waste acid and flue gas enter the tank body 1 in a tangential direction through the connecting pipe 20 and the tangential air inlet 5. The liquid in the gas-liquid mixture is separated to the bottom of the tank under the action of gravity. The waste acid in the tank body 1 is then discharged from the tank body 1 through the top and side wall filter holes 9 of the PVDF filter barrel 8. The waste acid discharged from the tank body is then pumped back to the pre-concentrator 21 by the pre-concentration circulation pump 22 for recycling. The gas with a small amount of liquid in the gas-liquid mixture spirals up in the tank body 1 and enters the post-wash tower from the top air outlet 6 of the tank body 1. When lumpy scale is generated on the tank wall of the tank body 1 and falls off under the action of gravity and a slight negative pressure (-35 mbar), the lumpy scale will be filtered and blocked by the PVDF filter barrel 8, so that the lumpy scale will not be discharged from the tank body 1 and will not enter the pre-concentration circulation pump, thereby preventing damage to the pre-concentration circulation pump and ensuring the orderly and smooth operation of the system.

[0024] When the machine is shut down in winter, the temperature sensor 13 monitors the internal temperature of the tank in real time and feeds it back to the PLC controller 14. When the PLC controller 14 determines that the real-time temperature inside the tank is lower than the preset safety value, the PLC controller 14 controls the opening of the steam valve 12, so that the high-temperature steam from the steam source 11 enters the tank 1 through the steam valve 12 and the steam port 10, thereby heating the inside of the tank. When the internal temperature of the tank reaches the set value, the PLC controller 14 controls the closing of the steam valve 12, thereby avoiding excessive temperature drop of the separation tank when the machine is shut down; thereby reducing the shrinkage and cracking of the PVDF lining caused by excessive temperature drop, and further extending the service life of the equipment;

[0025] When the tank body 1 is being inspected, the worker opens the manhole cover 16 and then enters the tank body 1 through the manhole 15 to clean the massive scale.

[0026] The advantages of the present invention are: (1) changing the wall structure of the separation tank: a PVDF reinforcement ring is added to the PVDF lining, and is bonded to and coated with FRP fiberglass together with the lining. When the machine is shut down and cooled, interlayer shear force will be generated between the PVDF reinforcement ring and the fiberglass coated on it. Under the action of the interlayer shear force, the FRP outer coating will limit the thermal expansion of the PVDF lining and will not have a significant impact on the performance of the composite separation tank, thereby reducing the shrinkage and cracking of the PVDF lining caused by temperature drop; (2) the thickness of the PVDF lining is designed to be 6mm, which effectively increases the high-temperature creep resistance of the PVDF lining and further extends the service life of the separation tank; (3) a steam heating mechanism is added to prevent the tank body from stratification and PVDF cracking due to excessive temperature drop, further extending the service life of the separation tank; (4) a filtering structure is added to the bottom of the tank body. Through the structural design of the PVDF filter barrel, the block scale generated on the wall of the separation tank is effectively prevented from falling into the pre-concentration circulation pump, thereby preventing damage to the pre-concentration circulation pump and ensuring the orderly and smooth operation of the system.

[0027] The above description is only a preferred embodiment of the present invention and does not constitute any other form of limitation to the present invention. Any modification or equivalent change made based on the technical essence of the present invention shall still fall within the scope of protection required by the present invention.

Claims

1. An acid regeneration separation tank, characterized in that: The PVDF filter barrel is fixed at the bottom of the tank body, and the PVDF filter barrel is provided with a plurality of filter holes for filtering block scales.

2. The acid regeneration separation tank according to claim 1, characterized in that: The thickness of the PVDF lining of the tank is 6mm.

3. The acid regeneration separation tank according to claim 1, characterized in that: The structure of the heating mechanism includes: a steam port is provided on the side wall of the tank body, the steam port is provided with a steam valve connected to the steam source, a temperature sensor is provided in the tank body for real-time monitoring of the internal temperature of the tank body, and the temperature sensor and the steam valve are simultaneously connected to the PLC controller signal.

4. An acid regeneration separation tank according to claim 1, 2 or 3, characterized in that: A manhole for easy maintenance is provided on the side wall of the tank body, and a manhole cover for easy opening or closing the manhole is provided at the manhole.

5. The acid regeneration separation tank according to claim 4, characterized in that: A pre-separation tank is provided on the outside of the tank body, an inlet is provided on the top of the pre-separation tank, an overflow outlet is provided on the upper side wall of the pre-separation tank, a filter is provided at the overflow outlet, and the overflow outlet of the pre-separation tank is connected to the tangential air inlet on the side wall of the tank body through a connecting pipe.

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