Solvent recovery system of multi-effect concentration equipment

Abstract

A solvent recovery system of a multi-effect concentration device comprises a concentration box, a heat exchange pipe, a heat exchanger and an absorption tower, the bottom of the concentration box is communicated with a liquid discharge pipe, the outer wall of the liquid discharge pipe is coated with the heat exchange pipe, the top of the concentration box is communicated with an exhaust pipe, and the other end of the exhaust pipe is communicated with an air inlet of the heat exchange pipe. A liquid outlet of the heat exchanger is communicated with the top of the absorption tower through a liquid outlet pipe, and the bottom of the absorption tower is communicated with a liquid conveying pipe; according to the utility model, the condensate water generated by each heater is collected on the basis of the original equipment, the condensate water is quickly cooled through the plate heat exchanger, and then the cooled condensate water is drained into the vacuum buffer tank and is recycled, so that the recycling efficiency of ammonia gas is remarkably improved, the emission of the ammonia gas is reduced, and the production cost is reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of pharmaceutical and chemical production equipment, and particularly relates to a solvent recovery system for multi-effect concentration equipment. Background Art

[0002] Multi-effect concentration equipment is widely used in the pharmaceutical, food, chemical and other industries due to its high efficiency in heat source utilization, and is regarded as an upgraded product of traditional membrane concentrators. This type of equipment improves the concentration efficiency through multiple evaporation and condensation processes to achieve energy saving; distillation concentration is a common chemical unit operation, which separates the components in the liquid mixture according to their different volatility to obtain purified components. This operation is often used for product purification and recovery, or raw material refining.

[0003] In the production process of neomycin sulfate, the neomycin desorption solution contains a certain amount of ammonia solution. In order to ensure that the subsequent production steps are not affected by ammonia residues and to ensure the quality of the finished product, the ammonia component needs to be removed through a concentration process. However, when using a multi-effect concentration device for concentration and ammonia removal operations, a large amount of ammonia will evaporate with the steam and escape through the vacuum system, which is not only detrimental to the environmental control of the production area, but also affects the recovery and reuse of ammonia, thereby affecting production cost control.

[0004] In addition, during the operation of the current multi-effect concentration equipment, the ammonia and water vapor mixture evaporated from each effect evaporator is supplied to the next stage heater to heat the material. The high temperature of the cooling water (containing ammonia) is not conducive to the dissolution of ammonia in water. Therefore, it is necessary to improve the existing concentration system to improve the recovery rate of ammonia. Summary of the invention

[0005] In view of the technical problems existing in the background technology, the utility model proposes a solvent recovery system for a multi-effect concentration equipment. This system collects the condensed water generated by each heater on the basis of the original equipment, and quickly cools it down through a plate heat exchanger, and then drains the condensed water with the lowered temperature into a vacuum buffer tank for recovery, thereby significantly improving the recovery efficiency of ammonia, reducing ammonia emissions and reducing production costs.

[0006] In order to solve the above technical problems, the utility model adopts the following technical solutions to achieve:

[0007] A solvent recovery system for a multi-effect concentration device comprises a concentration box, a heat exchange tube, a heat exchanger and an absorption tower. The bottom of the concentration box is connected to a drain pipe, the outer wall of the drain pipe is coated with a heat exchange tube, the top of the concentration box is connected to an exhaust pipe, the other end of the exhaust pipe is connected to the air inlet of the heat exchange tube, the air outlet of the heat exchange tube is connected to the liquid inlet of the heat exchanger through the liquid inlet pipe, the liquid outlet of the heat exchanger is connected to the top of the absorption tower through the liquid outlet pipe, and the bottom of the absorption tower is connected to the liquid infusion pipe.

[0008] In a preferred embodiment, the heat exchange tube includes a tube wall, a heat insulation layer, and a heat exchange plate. The tube wall is sleeved on the outer wall of the liquid discharge pipe, the outer side of the tube wall is coated with a heat insulation layer, and a heat exchange plate is installed inside the tube wall. The liquid discharge pipe is perpendicularly inserted into the heat exchange plate, and the heat exchange plate is a mesh plate structure.

[0009] In a preferred embodiment, a slope plate is provided at the bottom of the tube wall, and the slope plate is higher on the air inlet side than on the air outlet side inside the tube wall.

[0010] In a preferred embodiment, the tower wall of the absorption tower is a hollow structure and forms a tower wall cavity. The tower wall cavity is connected to the water inlet pipe, and atomizing nozzles are evenly installed on the inner wall of the absorption tower.

[0011] In a preferred embodiment, the atomizing nozzles are perpendicularly inserted into the inner wall of the absorption tower, and the other ends of the atomizing nozzles are connected to the tower wall cavity.

[0012] In a preferred embodiment, a spray plate is connected to the end of the liquid outlet pipe, and the spray plate is arranged at the inner top of the absorption tower.

[0013] The present patent can achieve the following beneficial effects:

[0014] 1. This system can collect the condensed water in the heat exchanger, cool and spray and recycle the collected condensed water, improving the utilization rate of the tail gas and the recovery rate of ammonia in the tail gas at the same time;

[0015] 2. The heat exchange tube in this system adopts a multi-layer plate heat exchange system, which can significantly improve the heat conversion rate and heating efficiency;

[0016] 3. The absorption tower in this system has a double-layer structure and adopts a special spray absorption system, which ensures the airtightness of the device and further improves the absorption efficiency of the absorption tower. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The following further describes the present utility model with reference to the drawings and embodiments:

[0018] Figure 1 Schematic diagram of the overall structure of the system of the present utility model Figure 1 ;

[0019] Figure 2 Schematic diagram of the overall structure of the system of the present utility model Figure 2 ;

[0020] Figure 3 Internal structure cross-sectional view of the heat exchange tube of the present utility model;

[0021] Figure 4 Internal structure sectional view of the absorption tower of the present utility model.

[0022] In the figure: concentration tank 1, exhaust pipe 2, liquid discharge pipe 3, heat exchange pipe 4, pipe wall 401, heat insulation layer 402, slope plate 403, heat exchange plate 404, liquid inlet pipe 5, liquid outlet pipe 6, spray plate 601, heat exchanger 7, absorption tower 8, tower wall cavity 801, atomizing nozzle 802, water inlet pipe 803, liquid delivery pipe 9. Detailed implementation

[0023] As Figure 1 and Figure 2 shown, a solvent recovery system for a multi-effect concentration device includes a concentration tank 1, a heat exchange pipe 4, a heat exchanger 7, and an absorption tower 8. The bottom of the concentration tank 1 is connected to a liquid discharge pipe 3, and the outer wall of the liquid discharge pipe 3 is covered with a heat exchange pipe 4. The top of the concentration tank 1 is connected to an exhaust pipe 2, and the other end of the exhaust pipe 2 is connected to the air inlet of the heat exchange pipe 4. The air outlet of the heat exchange pipe 4 is connected to the liquid inlet of the heat exchanger 7 through a liquid inlet pipe 5. The liquid outlet of the heat exchanger 7 is connected to the top of the absorption tower 8 through a liquid outlet pipe 6, and the bottom of the absorption tower 8 is connected to a liquid delivery pipe 9;

[0024] During the operation of the system, the concentration tank 1 heats and concentrates the neomycin desorption liquid. The concentrated solution is output through the liquid discharge pipe 3 to the next processing location. The tail gas containing ammonia is transported into the heat exchange pipe 4 through the exhaust pipe and heats the concentrated material to improve the subsequent processing efficiency of the material;

[0025] The temperature of the heated tail gas is still relatively high and not conducive to absorption. Therefore, the water-vapor mixture is transported into the heat exchanger 7 through the liquid inlet pipe 5 for cooling. The cooled tail gas is finally transported into the absorption tower 8 through the liquid outlet pipe 6 for absorption, which not only ensures the heat energy utilization rate of the tail gas but also improves the secondary utilization rate of the tail gas.

[0026] Preferably, as Figure 3 described, the heat exchange pipe 4 includes a pipe wall 401, a heat insulation layer 402, and a heat exchange plate 404. The pipe wall 401 is sleeved on the outer wall of the liquid discharge pipe 3, the outside of the pipe wall 401 is covered with a heat insulation layer 402, and a heat exchange plate 404 is installed inside the pipe wall 401. The liquid discharge pipe 3 is vertically inserted into the heat exchange plate 404, and the heat exchange plate 404 is a mesh plate structure; the heat exchange plate 404 is made of a material with good thermal conductivity. The high-temperature tail gas can freely pass through the heat exchange plate 404 and heat the heat exchange plate 404. The heated heat exchange plate 404 then heats the outer wall of the liquid discharge pipe 3, thereby effectively improving the heat energy utilization rate of the tail gas.

[0027] Preferably, as Figure 3As described above, a ramp plate 403 is provided at the bottom of the pipe wall 401. The ramp plate 403 is higher on the air inlet side than on the air outlet side inside the pipe wall 401. The water-vapor mixture after heat exchange may form liquid inside the pipe wall 401, and the ramp plate 403 can smoothly introduce it to the bottom right side of the heat exchange tube 4 and flow into the liquid inlet pipe 5.

[0028] The preferred solution is as Figure 3 As described above, the tower wall of the absorption tower 8 is of a hollow structure and forms a tower wall cavity 801. The tower wall cavity 801 is communicated with the water inlet pipe 803. Atomizing nozzles 802 are evenly arranged at the inner wall of the absorption tower 8. The atomizing nozzles 802 are vertically inserted into the inner wall of the absorption tower 8, and the other end of the atomizing nozzles 802 is communicated with the tower wall cavity 801. The end of the liquid outlet pipe 6 is communicated with a spray plate 601, and the spray plate 601 is arranged at the inner top of the absorption tower 8.

[0029] For the absorption tower 8, the water-vapor mixture after heat exchange and cooling is input into the spray plate 601 through the liquid outlet pipe 6 and sprayed downward in a dispersed state. At the same time, water is injected into the tower wall cavity 801 through the water inlet pipe 803 and finally sprayed in a mist form through the atomizing nozzles 802. At this time, the tail gas mixture sprayed dispersedly by the spray plate 601 and the misty water sprayed by the atomizing nozzles 802 will be fully mixed and absorbed in the inner cavity of the absorption tower 8. When the ammonia in the tail gas is fully absorbed, it is output through the liquid delivery pipe 9 at the bottom of the absorption tower 8 and reused.

[0030] The above embodiments are only the preferred technical solutions of the present invention and should not be regarded as limitations on the present invention. The protection scope of the present invention should be the technical solutions recorded in the claims, including the equivalent replacement solutions of the technical features in the technical solutions recorded in the claims. That is, the equivalent replacement improvements within this scope are also within the protection scope of the present invention.

Claims

1. A solvent recovery system for a multi-effect concentration device, comprising a concentration tank (1), a heat exchange tube (4), a heat exchanger (7) and an absorption tower (8), characterized in that: The bottom of the concentration tank (1) is connected to a drain pipe (3), the outer wall of the drain pipe (3) is coated with a heat exchange pipe (4), the top of the concentration tank (1) is connected to an exhaust pipe (2), the other end of the exhaust pipe (2) is connected to the air inlet of the heat exchange pipe (4), the air outlet of the heat exchange pipe (4) is connected to the liquid inlet of the heat exchanger (7) through the liquid inlet pipe (5), the liquid outlet of the heat exchanger (7) is connected to the top of the absorption tower (8) through the liquid outlet pipe (6), and the bottom of the absorption tower (8) is connected to the liquid infusion pipe (9).

2. The solvent recovery system for multiple-effect concentration equipment according to claim 1, characterized in that: The heat exchange tube (4) comprises a tube wall (401), a heat insulation layer (402) and a heat exchange plate (404); the tube wall (401) is sleeved on the outer wall of the liquid discharge tube (3); the outer side of the tube wall (401) is coated with the heat insulation layer (402); the heat exchange plate (404) is arranged inside the tube wall (401); the liquid discharge tube (3) and the heat exchange plate (404) are vertically plugged; and the heat exchange plate (404) is a mesh plate structure.

3. The solvent recovery system for multiple-effect concentration equipment according to claim 2, characterized in that: A slope plate (403) is provided at the bottom of the tube wall (401), and the slope plate (403) is higher on the air inlet side than on the air outlet side in the tube wall (401).

4. The solvent recovery system for multiple-effect concentration equipment according to claim 1, characterized in that: The tower wall of the absorption tower (8) is a hollow structure and forms a tower wall cavity (801). The tower wall cavity (801) is connected to the water inlet pipe (803). Atomizing nozzles (802) are evenly installed on the inner wall of the absorption tower (8).

5. The solvent recovery system for multiple-effect concentration equipment according to claim 4, characterized in that: The atomizing nozzle (802) is vertically plugged into the inner wall of the absorption tower (8), and the other end of the atomizing nozzle (802) is connected to the tower wall cavity (801).

6. The solvent recovery system for multiple-effect concentration equipment according to claim 1, characterized in that: The end of the liquid outlet pipe (6) is connected to a spray plate (601), and the spray plate (601) is arranged at the top end inside the absorption tower (8).

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