A device and method for concentrating dilute acid using a concentration column
By using a concentration tower device and concentration method, the problems of complex equipment and high energy consumption in existing dilute acid concentration processes have been solved, achieving equipment simplification, space reduction and energy consumption reduction, and improving the efficiency and stability of dilute acid concentration.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- NANTONG JINGTONG GRAPHITE EQUIP
- Filing Date
- 2026-04-27
- Publication Date
- 2026-06-26
AI Technical Summary
The existing dilute acid concentration process has technical defects such as a large number of equipment, large footprint, complicated pipeline layout, and many sealing leakage points, resulting in complex equipment configuration and high energy consumption.
The system employs a concentration tower device, combined with components such as a dilute acid preheater, a concentrated acid intermediate tank, a condenser, a dilute acid pump, and a heat pump. The dilute acid is diffused through falling film evaporation and spray nozzles, and the heat source is recovered using the heat pump and condenser. In conjunction with an air agitator, mass and heat transfer are enhanced, thereby achieving efficient concentration of dilute acid.
Simplify equipment configuration, reduce floor space, reduce piping and leakage points, improve steam utilization, reduce energy consumption, and enhance concentration efficiency and process stability.
Smart Images
Figure CN122273133A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of chemical technology, specifically to an apparatus and method for concentrating dilute acid using a concentration tower. Background Technology
[0002] Dilute acid concentration is achieved by removing water from dilute acid solutions to increase acid concentration, thereby enabling the recycling of waste acid, reducing hazardous waste generation, and lowering storage, transportation, and treatment costs. Currently, most existing dilute acid concentration processes use single-effect or multi-effect evaporation devices, which have technical drawbacks such as a large number of devices, large floor space, complicated pipeline layout, and numerous sealing leakage points. Summary of the Invention
[0003] The technical problem to be solved by the present invention is to provide an apparatus and a concentration method for concentrating dilute acid using a concentration tower, which addresses the shortcomings of the prior art.
[0004] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: An apparatus for concentrating dilute acid using a concentration tower includes a concentration tower, a dilute acid preheater, a concentrated acid intermediate tank, a condenser I, a condenser II, a dilute acid pump, and a heat pump. The concentration tower is internally separated by a partition. A heat exchanger I is installed in the upper section of the concentration tower, and a heat exchanger II is installed in the lower section of the concentration tower. An acid inlet is provided at the upper end of the concentration tower, which is connected to a liquid inlet of heat exchanger I. A spray pipe is connected to the lower section of the concentration tower, and a liquid outlet of heat exchanger I is connected to the spray pipe. A nozzle is installed on the spray pipe, and the nozzle is located above heat exchanger II. An acid outlet is provided at the lower end of the concentration tower, which is connected to the concentrated acid intermediate tank. The concentrated acid outlet of the concentrated acid intermediate tank is connected to a concentrated acid pump. The dilute acid preheater is provided with a dilute acid inlet at one end and a dilute acid outlet at the other end. The dilute acid inlet is connected to a dilute acid pump, and the dilute acid outlet is connected to the acid inlet at the top of the concentration tower. A liquid outlet 2 is provided below the heat exchanger 1, and the liquid outlet 2 is connected to the acid inlet at the top of the concentration tower via a circulation pump. The heat pump is connected to the heat source inlet of heat exchanger one, the heat source outlet of heat exchanger one is connected to the heat source inlet of heat exchanger two through a heat delivery pipe, and the heat source outlet of heat exchanger two is connected to condenser one. A flash heat source outlet is provided above the lower section of the concentration tower. The flash heat source outlet is connected to the preheating inlet on one side of the dilute acid preheater. A preheating heat source outlet is provided on the other side of the dilute acid preheater and is connected to the second condenser.
[0005] Furthermore, heat exchanger one is installed vertically, and heat exchanger two is installed horizontally.
[0006] Furthermore, a condensate outlet is provided on one side of the heat exchanger, and a condensate flash tank is connected to the condensate flash tank. The drain outlet of the condensate flash tank leads to the acidic condensate collection tank, and the heat outlet of the condensate flash tank is connected to the heat supply pipe.
[0007] Furthermore, the heat delivery pipe is equipped with a connecting pipe that connects to the heat pump.
[0008] Furthermore, an air agitator is installed at the acid outlet at the lower end of the concentration tower.
[0009] Furthermore, the condenser includes condenser A and tail gas condenser A. Condenser A and tail gas condenser A are provided with a gas inlet, a liquid phase outlet and a tail gas outlet. The gas inlet of condenser A is connected to the heat source outlet of heat exchanger II. The liquid phase outlet of condenser A leads to a liquid seal tank. The tail gas outlet of condenser A is connected to the gas inlet of tail gas condenser A. The liquid phase outlet of tail gas condenser A leads to a liquid seal tank. A vacuum pump is connected to the tail gas outlet of tail gas condenser A. Cooling water inlet and cooling water outlet are provided on condenser A and tail gas condenser A. The cooling water inlet and cooling water outlet are connected to a cooling water station.
[0010] Furthermore, the second condenser includes a condenser B and a tail gas condenser B. The condenser B and tail gas condenser B are equipped with a gas inlet 2, a liquid phase outlet 2, and a tail gas outlet 2. The gas inlet 2 of the condenser B is connected to the preheating heat source outlet of the dilute acid preheater. The liquid phase outlet 2 of the condenser B leads to a liquid seal tank. The tail gas outlet 2 of the condenser B is connected to a steam jet pump, which is connected to the gas inlet 2 of the tail gas condenser B. The liquid phase outlet 2 of the tail gas condenser B leads to a liquid seal tank. The tail gas outlet 2 of the tail gas condenser B is connected to a vacuum pump. The condenser B and tail gas condenser B are equipped with a cooling water inlet 3 and a cooling water outlet 4, which are connected to a cooling water station.
[0011] Furthermore, the dilute acid pump is equipped with a flow meter.
[0012] A concentration method for dilute acid using a concentration tower involves pumping purified dilute acid to a dilute acid preheater. The heat source inside the preheater is the secondary steam generated by flash evaporation in the lower section of the concentration tower. After preheating, the dilute acid is fed into the concentration tower. Heat exchanger one in the upper section of the concentration tower uses a falling film evaporation process for preliminary concentration of the dilute acid. The heat source for heat exchanger one is steam supplied by a heat pump, and it also absorbs some of the secondary steam generated by flash evaporation in the upper section of the concentration tower, achieving heat source replenishment and recovery. The resulting intermediate acid flows into a spray pipe in the lower section of the concentration tower and is diffused through nozzles on the spray pipe to the surface of the heat exchange tubes in heat exchanger two. Part of the heat source for heat exchanger two is the concentration tower itself. The secondary steam from the upper flash evaporation and the flash steam generated from the condensate in the upper section of the concentration tower are further heated, evaporated, and concentrated through heat exchanger two. The air agitator at the bottom of the concentration tower enhances mass and heat transfer, improves the fluidity of the concentrated acid, and the concentrated acid enters the intermediate concentrated acid tank, which is then pumped to the subsequent processes by the concentrated acid pump. The tail gas generated in this process enters condenser one and condenser two for condensation treatment. The condensed liquid products flow into the liquid seal tank for collection and are then uniformly transported to the water treatment system for further treatment. The remaining non-condensable gases after condensation are extracted by a vacuum pump and transported to the waste gas treatment system to ensure that the emissions meet the standards.
[0013] Compared with the prior art, the present invention provides an apparatus and method for concentrating dilute acids using a concentration tower, which simplifies equipment configuration, reduces floor space, reduces pipelines and leakage points, has high steam utilization rate, low energy consumption, and is suitable for the concentration treatment of various dilute acids such as dilute phosphoric acid and dilute sulfuric acid. The concentration efficiency and process stability are significantly improved. Attached Figure Description
[0014] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a schematic diagram of the concentration tower of the present invention; Figure 3 This is a schematic diagram of the structure of the dilute acid preheater of the present invention; The components are as follows: 1. Concentration tower; 2. Dilute acid preheater; 3. Concentrated acid intermediate tank; 4. Dilute acid pump; 5. Heat pump; 6. Baffle; 7. Heat exchanger one; 8. Heat exchanger two; 9. Acid inlet; 10. Spray pipe; 11. Nozzle; 12. Acid outlet; 13. Concentrated acid pump; 14. Air agitator; 15. Dilute acid inlet; 16. Dilute acid outlet; 17. Circulation pump; 18. Heat source inlet one; 19. Heat source outlet one; 20. Heat supply pipe; 21. Heat source inlet two; 22. Heat source outlet two; 23. Condenser A; 24. Tail gas condenser A; 25. Liquid seal tank; 26. Vacuum pump; 27. Condensate outlet one; 28. Condensate flash tank; 29. Flash heat source outlet; 30. Preheating inlet; 31. Preheating heat source outlet; 32. Condenser B; 33. Tail gas condenser B; 34. Steam jet pump. Detailed Implementation
[0015] The technical solutions in the embodiments of the present invention will be clearly and completely described below.
[0016] like Figures 1-3 As shown, an apparatus for concentrating dilute acid using a concentration tower includes a concentration tower 1, a dilute acid preheater 2, a concentrated acid intermediate tank 3, a condenser I, a condenser II, a dilute acid pump 4, and a heat pump 5. The concentration tower 1 is internally divided into an upper section and a lower section by a partition 6. A heat exchanger I 7 is installed in the upper section of the concentration tower, and a heat exchanger II 8 is installed in the lower section. In this embodiment, the heat exchanger I 7 in the upper section is installed vertically, and the heat exchanger II 8 in the lower section is installed horizontally. An acid inlet 9 is provided at the upper end of the concentration tower, and the acid inlet 9 is connected to the liquid inlet of the heat exchanger I 7. A spray pipe 10 is connected to the lower section of the concentration tower. Liquid outlet 1 is connected to spray pipe 10. Spray pipe 10 is equipped with nozzle 11, which is located above heat exchanger 8. The vacuum difference between the upper and lower sections of the concentration tower is used to spray acid onto the heat exchange tubes of heat exchanger 8. Acid outlet 12 is provided at the lower end of the concentration tower. Acid outlet 12 is connected to concentrated acid intermediate tank 3. Concentrated acid pump 13 is connected to the concentrated acid outlet of concentrated acid intermediate tank 3. Concentrated acid pump 13 pumps concentrated acid from concentrated acid intermediate tank 3 and sends it to the next process. Air agitator 14 is installed at acid outlet 12 at the lower end of the concentration tower. Air agitator 14 injects air into concentrated acid to improve its fluidity and prevent concentrated acid from accumulating at acid outlet 12 at the lower end of the concentration tower.
[0017] The dilute acid preheater 2 is provided with a dilute acid inlet 15 at one end and a dilute acid outlet 16 at the other end. The dilute acid inlet 15 is connected to the dilute acid pump 4, which is equipped with a flow meter. The dilute acid outlet 16 is connected to the acid inlet 9 at the top of the concentration tower. A liquid outlet 2 is provided below the heat exchanger 7. The liquid outlet 2 is connected to the acid inlet 9 at the top of the concentration tower through a circulation pump 17. The amount of acid flowing into the lower section of the concentration tower is controlled by the circulation pump 17.
[0018] The heat pump 5 is connected to the heat source inlet 18 of heat exchanger 7. The heat source of heat exchanger 7 is mainly external steam. At the same time, the heat pump 5 draws in some secondary steam generated by flash evaporation in the upper section of the concentration tower to achieve heat source replenishment and recovery. The heat source outlet 19 of heat exchanger 7 is connected to the heat source inlet 21 of heat exchanger 8 through a heat supply pipe 20. The steam from flash evaporation in heat exchanger 7 is sent into heat exchanger 8 through the heat supply pipe 20 to evaporate the acid liquid as a heat source. A connecting pipe is provided on the heat supply pipe 20 to connect to the heat pump 5 to achieve heat source replenishment and recovery. The heat source outlet 22 of heat exchanger 8 is connected to condenser 1. The condenser 1 includes condenser A23 and tail gas condenser A24. Condenser A23 and tail gas condenser A24 are provided with a gas inlet, a liquid outlet, and a tail gas outlet. Outlet 1: The gas inlet 1 of condenser A23 is connected to the heat source outlet 21 of heat exchanger 28. The exhaust gas vapor generated by heat exchanger 28 enters condenser A23 through heat source outlet 21. The liquid phase outlet 1 of condenser A23 leads to liquid seal tank 25, which leads to water treatment station. The tail gas outlet 1 of condenser A23 is connected to the gas inlet 1 of tail gas condenser A24. The liquid phase outlet 1 of tail gas condenser A24 also leads to liquid seal tank 25. The tail gas outlet 1 of tail gas condenser A24 is connected to vacuum pump 26, which draws a vacuum to power the heat source. Cooling water inlet 1 and cooling water outlet 1 are provided on condenser A23 and tail gas condenser A24, respectively. Cooling water inlet 1 and cooling water outlet 1 are connected to cooling water station, which provides cooling water to cool the exhaust gas vapor.
[0019] The heat exchanger 7 has a condensate outlet 27 on its side, which is connected to a condensate flash tank 28. The drain of the condensate flash tank 28 leads to an acid-free condensate collection tank. The heat outlet of the condensate flash tank 28 is connected to the heat supply pipe 20 through a pipeline. The condensate flash tank 28 recovers heat from the condensate to replenish the heat in the heat exchanger 8.
[0020] A flash heat source outlet 29 is provided above the lower section of the concentration tower. The flash heat source outlet 29 is connected to the preheating inlet 30 on one side of the dilute acid preheater 2. A preheating heat source outlet 31 is provided on the other side of the dilute acid preheater 2. The preheating heat source outlet 31 is connected to the second condenser. The second condenser includes a condenser B32 and a tail gas condenser B33. The condenser B32 and the tail gas condenser B33 are provided with a second gas inlet, a second liquid phase outlet, and a second tail gas outlet. The second gas inlet of the condenser B32 is connected to the preheating heat source outlet 31 of the dilute acid preheater 2. The second liquid phase outlet of the condenser B32 is connected to the preheating heat source outlet 31 of the dilute acid preheater 2. A steam jet pump 34 is connected to the tail gas outlet 2 of the condenser B32, which leads to the liquid seal tank 25. The steam jet pump 34 is connected to the gas inlet 2 of the tail gas condenser B33. The steam jet pump 34 uses steam as power to create a vacuum pressure difference between the lower and upper sections of the concentration tower. The liquid phase outlet 2 of the tail gas condenser B33 leads to the liquid seal tank 25. The tail gas outlet 2 of the tail gas condenser B33 is connected to the vacuum pump 26. Cooling water inlet 3 and cooling water outlet 4 are provided on the condenser B32 and the tail gas condenser B33. Cooling water inlet 3 and cooling water outlet 4 are connected to the cooling water station.
[0021] When concentrating dilute acid in the concentration tower, the purified dilute acid is sent to the dilute acid preheater 2 by the dilute acid pump 4. The heat source inside the dilute acid preheater 2 is the secondary steam generated by the flash evaporation in the lower section of the concentration tower. After the dilute acid is preheated, it is sent into the concentration tower 1. The heat exchanger 7 in the upper section of the concentration tower uses a falling film evaporation process to perform preliminary concentration of the dilute acid. The heat source of the heat exchanger 7 is the steam provided by the heat pump 5. At the same time, it draws in some of the secondary steam generated by the flash evaporation in the upper section of the concentration tower to achieve heat source replenishment and recovery. The obtained intermediate acid flows into the spray pipe 10 in the lower section of the concentration tower. The intermediate acid is diffused to the surface of the heat exchange tubes of the heat exchanger 8 through the nozzles 11 on the spray pipe 10. Part of the heat source of the heat exchanger 8 is the concentration tower. The secondary steam from the upper flash evaporation and the flash steam generated from the condensate in the upper section of the concentration tower after flash evaporation in the condensate flash tank are further heated, evaporated, and concentrated by heat exchanger 2. The air agitator 14 at the lower end of the concentration tower enhances the mass and heat transfer effect and improves the fluidity of the concentrated acid. The concentrated acid after concentration enters the intermediate concentrated acid tank 3 and is transported to the subsequent process by concentrated acid pump 13. The tail gas generated in this process enters condenser 1 and condenser 2 for condensation treatment. The liquid phase product after condensation flows into the liquid seal tank 25 for collection and is uniformly transported to the water treatment system for subsequent treatment. The remaining non-condensable gas after condensation is extracted by vacuum pump 26 and transported to the waste gas treatment system to ensure that the emission meets the standards.
[0022] This invention is not limited to the embodiments described. Those skilled in the art can make some modifications or changes without departing from the spirit and scope of this invention. Therefore, the scope of protection of this invention is defined by the claims.
Claims
1. An apparatus for concentrating dilute acid using a concentration tower, characterized in that: The system includes a concentration tower, a dilute acid preheater, a concentrated acid intermediate tank, a condenser 1, a condenser 2, a dilute acid pump, and a heat pump. The concentration tower is internally separated by a partition. A heat exchanger 1 is installed in the upper section of the concentration tower, and a heat exchanger 2 is installed in the lower section of the concentration tower. An acid inlet is provided at the upper end of the concentration tower, which is connected to the liquid inlet 1 of the heat exchanger 1. A spray pipe is connected to the lower section of the concentration tower, and the liquid outlet 1 of the heat exchanger 1 is connected to the spray pipe. A nozzle is installed on the spray pipe, and the nozzle is located above the heat exchanger 2. An acid outlet is provided at the lower end of the concentration tower, which is connected to the concentrated acid intermediate tank. The concentrated acid outlet of the concentrated acid intermediate tank is connected to a concentrated acid pump. The dilute acid preheater is provided with a dilute acid inlet at one end and a dilute acid outlet at the other end. The dilute acid inlet is connected to a dilute acid pump, and the dilute acid outlet is connected to the acid inlet at the top of the concentration tower. A liquid outlet 2 is provided below the heat exchanger 1, and the liquid outlet 2 is connected to the acid inlet at the top of the concentration tower via a circulation pump. The heat pump is connected to the heat source inlet of heat exchanger one, the heat source outlet of heat exchanger one is connected to the heat source inlet of heat exchanger two through a heat delivery pipe, and the heat source outlet of heat exchanger two is connected to condenser one. A flash heat source outlet is provided above the lower section of the concentration tower. The flash heat source outlet is connected to the preheating inlet on one side of the dilute acid preheater. A preheating heat source outlet is provided on the other side of the dilute acid preheater and is connected to the second condenser.
2. The apparatus for concentrating dilute acid using a concentration tower according to claim 1, characterized in that: Heat exchanger one is installed vertically, and heat exchanger two is installed horizontally.
3. The apparatus for concentrating dilute acid using a concentration tower according to claim 1, characterized in that: The heat exchanger has a condensate outlet on one side, which is connected to a condensate flash tank. The drain outlet of the condensate flash tank leads to an acidic condensate collection tank, and the heat outlet of the condensate flash tank is connected to a heat delivery pipe.
4. The apparatus for concentrating dilute acid using a concentration tower according to claim 1, characterized in that: The heat delivery pipe is equipped with a connecting pipe that connects to the heat pump.
5. The apparatus for concentrating dilute acid using a concentration tower according to claim 1, characterized in that: An air agitator is installed at the acid outlet at the lower end of the concentration tower.
6. The apparatus for concentrating dilute acid using a concentration tower according to claim 1, characterized in that: The condenser includes condenser A and tail gas condenser A. Condenser A and tail gas condenser A are provided with a gas inlet, a liquid phase outlet and a tail gas outlet. The gas inlet of condenser A is connected to the heat source outlet of heat exchanger II. The liquid phase outlet of condenser A leads to a liquid seal tank. The tail gas outlet of condenser A is connected to the gas inlet of tail gas condenser A. The liquid phase outlet of tail gas condenser A leads to a liquid seal tank. A vacuum pump is connected to the tail gas outlet of tail gas condenser A. Cooling water inlet and cooling water outlet are provided on condenser A and tail gas condenser A. The cooling water inlet and cooling water outlet are connected to a cooling water station.
7. The apparatus for concentrating dilute acid using a concentration tower according to claim 6, characterized in that: The second condenser includes condenser B and tail gas condenser B. Condenser B and tail gas condenser B are provided with a gas inlet 2, a liquid phase outlet 2, and a tail gas outlet 2. The gas inlet 2 of condenser B is connected to the preheating heat source outlet of the dilute acid preheater. The liquid phase outlet 2 of condenser B leads to the liquid seal tank. The tail gas outlet 2 of condenser B is connected to a steam jet pump, which is connected to the gas inlet 2 of tail gas condenser B. The liquid phase outlet 2 of tail gas condenser B leads to the liquid seal tank. The tail gas outlet 2 of tail gas condenser B is connected to a vacuum pump. Condenser B and tail gas condenser B are provided with a cooling water inlet 3 and a cooling water outlet 4, which are connected to a cooling water station.
8. The apparatus for concentrating dilute acid using a concentration tower according to claim 1, characterized in that: The dilute acid pump is equipped with a flow meter.
9. A concentration method for dilute acid using a concentration tower according to any one of claims 1 to 8, characterized in that: After purification, the dilute acid is pumped to the dilute acid preheater. The heat source inside the dilute acid preheater is the secondary steam generated by flash evaporation in the lower section of the concentration tower. After preheating, the dilute acid is sent into the concentration tower. The heat exchanger in the upper section of the concentration tower uses a falling film evaporation process to initially concentrate the dilute acid. The heat source of the heat exchanger is the steam provided by the heat pump. At the same time, it draws in some of the secondary steam generated by flash evaporation in the upper section of the concentration tower to achieve heat source replenishment and recovery. The resulting intermediate acid flows into the spray pipe in the lower section of the concentration tower. The intermediate acid is diffused to the surface of the heat exchange tubes in the second heat exchanger through the nozzles on the spray pipe. The heat source of the second heat exchanger is partly the secondary steam from flash evaporation in the upper section of the concentration tower and partly the flash steam generated by flash evaporation of the condensate in the upper section of the concentration tower after flash evaporation in the condensate flash tank. The second heat exchanger achieves further heating, evaporation and concentration. The air agitator at the lower end of the concentration tower enhances the mass and heat transfer effect and improves the fluidity of the concentrated acid. The concentrated acid after concentration enters the intermediate concentrated acid tank and is pumped to the subsequent process by the concentrated acid pump. The exhaust gas generated during this process enters condenser one and condenser two for condensation treatment. The condensed liquid products flow into the liquid seal tank for collection and are then uniformly transported to the water treatment system for further treatment. The remaining non-condensable gases after condensation are extracted by a vacuum pump and transported to the waste gas treatment system to ensure that emissions meet standards.