CN103920304B - Device for improving safety of leaching workshop and reducing solvent loss - Google Patents

Abstract

The invention discloses a device for improving the safety of a leaching workshop and reducing solvent loss. The spray tower has a packing layer inside, a water distribution pipe and a rotating drum are arranged above the packing layer, and holes are arranged on the water distribution pipe; a tube heat exchanger The upper tube side is connected to the bottom inlet of the spray tower, the top outlet of the spray tower is connected to the exhaust fan, and the exhaust fan outlet is connected to the exhaust port; one end of the main liquid separation tank is connected to the balance tank tube, and the other end is connected to the lower tube side of the tube-and-tube heat exchanger. The main liquid separation tank is connected to the secondary liquid separation tank through a connector, and the secondary liquid separation tank is also connected to the chilled water tank through a connector. The chilled water tank is connected to the lower shell side of the tube heat exchanger through a circulating water pump. The upper shell side is connected with the water distribution pipe; a freezing device is installed in the chilled water tank. The invention can generate slight negative pressure in the leaching system, reduce and eliminate solvent leakage in the leaching system, reduce solvent consumption to the greatest extent and eliminate potential safety hazards, and has simple and reliable structure and strong practicability.

Description

A device for improving the safety of the leaching workshop and reducing solvent loss

technical field

The invention relates to a device for preventing solvent leakage in a leaching workshop, improving safety and reducing solvent loss.

Background technique

Leaching is the use of solvents, especially organic solvents, to dissolve the target components in the material and then separate them. It is a commonly used technical method in industrial production and is widely used in food, biology, chemical and pharmaceutical fields.

Since the solvents used in most leaching workshops are organic solvents, which are highly volatile, flammable, and explosive, one of the key points in the operation of the leaching workshop is to avoid positive pressure in the leaching system, even a small positive pressure may Cause the solvent to volatilize and escape from the system, resulting in loss of solvent. The solvent vapor volatilized and escaped from the leaching system is easy to diffuse and enrich in the leaching workshop. Since most organic solvents are flammable, explosive and possibly toxic , thus posing a serious threat.

In order to reduce the leakage of solvent in the leaching system, the general leaching system is equipped with a balance tank. The balance tank is a device that connects the leaching equipment with a larger and longer pipeline to balance the pressure. However, the application of the balance tank has not fundamentally To prevent the leakage of solvents and prevent safety accidents. If a device is designed to pump air from the balance tank of the leaching system to form a slight negative pressure in the leaching system, and to completely recover the solvent vapor in the pumping air, it will not only reduce solvent loss, but also effectively eliminate the problem caused by positive pressure in the system. leakage and the resulting safety accidents.

Contents of the invention

The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a device with a simple structure and strong practicability, which can pump air to the balance tank of the leaching system to form a slight negative pressure in the leaching system, and to The solvent vapor in the gas is completely recovered, effectively eliminating the leakage caused by the positive pressure of the system and the safety accidents caused by it.

In order to overcome the deficiencies in the prior art, the present invention takes the following technical solutions:

A device for improving the safety of a leaching workshop and reducing solvent loss, including an exhaust fan, a spray tower, a tube-and-tube heat exchanger, a main liquid separation tank, a secondary liquid separation tank, a chilled water tank, and a circulating water pump, characterized in that: spraying The tower is a closed structure with upper and lower outlets, and there is a packing layer inside. There are water distribution pipes and drums above the packing layer. There are holes on the water distribution pipes. The water distribution pipes spray water through the holes to drive the drum and water distribution pipes to spin; The upper tube side is connected to the bottom inlet of the spray tower, the top outlet of the spray tower is connected to the exhaust fan, and the exhaust fan outlet is connected to the exhaust port; one end of the main liquid separation tank is connected to the balance tank tube, and the other end is connected to the lower tube side of the tube-and-tube heat exchanger. The main liquid separation tank is connected to the secondary liquid separation tank through a connector, the secondary liquid separation tank is connected to the chilled water tank through another connector, the chilled water tank is connected to the lower shell side of the tube heat exchanger through a circulating water pump, and the tube heat exchanger The upper shell side is connected to the water distribution pipe; the chilled water tank is equipped with a heat exchange coil, and the heat exchange coil is connected to the chiller.

The spray tower is provided with inspection holes and observation holes, which are usually closed and can be opened when necessary.

The packing layer in the spray tower is an object with a large surface area and a small volume, that is, an object that increases the surface area in the field of engineering technology, such as Raschig rings, Boolean rings, and saddle rings.

The upper part of the main liquid separation tank is provided with a solvent return pipe, which can return the solvent recovered and subjected to liquid separation treatment to the storage tank.

Both the main liquid distribution tank and the secondary liquid distribution tank are provided with liquid level gauges for easy observation of liquid levels.

The bottoms of the main liquid separation tank, the secondary liquid separation tank and the frozen water tank are all inverted conical structures, and the bottom of the cone is connected with a drain valve.

The chilled water tank is provided with a ball float valve and a float valve float, which is convenient for observing and controlling the water level of the chilled water tank.

Valves are provided between the inlet of the circulating water pump and the chilled water tank, between the outlet of the circulating water pump and the chilled water tank, and between the shell side of the tube-and-tube heat exchanger, so as to facilitate various functional operations.

The spray tower, the tube-and-tube heat exchanger, the main liquid separation tank, the secondary liquid separation tank and the chilled water tank are provided with insulation layers.

Work process of the present invention is as follows:

The gas from the balance tank enters the main liquid separation tank from the balance tank pipe, passes through the upper part, enters the tube side of the tube heat exchanger, passes through the tube tubes of the heat exchanger upwards, and flows in parallel with the chilled water in the shell side from bottom to top Heat; the chilled water reaches the upper part of the shell side of the tube heat exchanger upwards, enters the water distribution pipe and sprays out from the holes of the water distribution pipe, and the water distribution pipe sprays water in reverse through the holes to drive the rotating drum and the water distribution pipe to spin, so that the chilled water is dispersed evenly. Sprinkle, through layers of filling. In the packing layer, the updraft and the large-area downflow frozen water on the packing are directly contacted and large-area heat exchange is realized, so that the chilled water can efficiently and thoroughly absorb the heat in the gas, and condense the solvent vapor in it. Extract to empty.

The gas in the balance tank passes through the spray tower from bottom to top, and directly contacts and exchanges heat with the sprayed and falling frozen water, so that the solvent in the gas from the balance tank is condensed.

The chilled water carrying the solvent flows back through the tube heat exchanger, and directly contacts the rising exhaust gas in the tube side to exchange heat, so that the solvent vapor is condensed.

All the refrigerated water and condensed liquefied solvents are all confluent to the main liquid separation tank. The solvent density is low in the upper part of the water layer. Observe the stratification of water and solvent through the liquid level gauge. If there is too much solvent, you can open the valve on the solvent return pipe to realize the solvent reflow.

When the liquid level exceeds the position of the balance pipe of the connector, under the action of the connector, the water at the bottom of the main liquid distribution tank will overflow to the secondary liquid distribution tank, and finally overflow to the frozen water tank, and the two liquid distribution tanks will not be separated. Solvent overflows into the chilled water tank.

There is a heat exchange coil in the chilled water tank, and the heat exchange coil is connected to the chiller to cool down the water in the chilled water tank. The chilled water is controlled by a valve and enters the circulating water pump. The output can be divided into two channels. Strengthen the heat exchange between the inner coil of the chilled water tank and the water, and the other route valve to adjust the heat exchange chilled water circulation flow, and the float valve automatically replenishes water to the appropriate liquid level.

The core of this design is to condense the solvent by spraying and exchanging chilled water, combined with the condensation and separation of the solvent in the tube heat exchange, the evacuated gas basically does not contain solvent.

The pumping function of the device can generate micro-negative pressure in the leaching system, reduce and eliminate solvent leakage in the leaching system, reduce solvent consumption to the greatest extent and eliminate potential safety hazards.

Compared with prior art, the beneficial effect of the present invention is:

The gas rises in the tubes, the frozen water falls film, and the steam is heat-exchanged and condensed to capture. The low-temperature chilled water outside the tube ensures the efficient and thorough condensation of the steam in the tube. Thermal coefficient; the rising gas in the tube side is cooled and transferred by the large-area and efficient direct contact heat transfer of the packing layer, so that the solvent vapor can be further condensed thoroughly, and the tail gas emission can reach the lowest residual solvent.

Two-stage series-connected chilled water cooling and condensing steam ensure the desolvation effect of tail gas, and two-stage liquid separation and return flow at the bottom of the connector ensure that the return water does not contain solvents; Solvent leakage will occur, eliminating potential safety hazards to the greatest extent.

The invention has simple and reliable structure, strong practicability and broad market prospect.

Description of drawings

Fig. 1 is a schematic plan view of the present invention.

Each label in the figure means:

1. Air outlet; 2. Exhaust fan; 3. Water distribution pipe; 4. Drum; 5. Inspection hole; 6. Observation hole; 7. Spray tower; 8. Valve a; 9. Packing layer; 10. Column Tube heat exchanger; 11. Balance tank tube; 12. Main liquid separation tank; 13. Solvent return pipe; 14. Liquid level gauge a; 15. Solvent and water boundary; 16. Connector a; 17. Drainage valve a ;18. Secondary liquid tank; 19. Connector b; 20. Liquid level gauge b; 21. Connector balance pipe; 22. Chiller; 23. Heat exchange coil; 24. Drain valve b; 25. Float valve Float ball; 26, ball float valve; 27, valve b; 28, chilled water tank; 29, circulating water pump; 30, valve c; 31, sewage valve c.

Detailed ways

Now in conjunction with accompanying drawing, the present invention is described in further detail.

As shown in Figure 1, the device for improving the safety of the leaching workshop and reducing solvent loss includes an exhaust fan 2, a spray tower 7, a tube heat exchanger 10, a main liquid separation tank 12, a secondary liquid separation tank 18, a chilled water tank 28 and The circulating water pump 29 and the spray tower 7 are closed structures with upper and lower outlets, and there is a packing layer 9 inside. The water distribution pipe 3 and the drum 4 are arranged above the packing layer 9. The water distribution pipe 3 is provided with holes, and the water distribution pipe 3 sprays water through the holes. Drive the rotary drum 4 and the water distribution pipe 3 to spin; the upper tube side of the tube heat exchanger 10 is connected to the bottom inlet of the spray tower 7, the top outlet of the spray tower 7 is connected to the exhaust fan 2, and the outlet of the exhaust fan 2 is connected to the exhaust outlet 1; One end of the liquid tank 12 is connected to the balance tank pipe 11, and the other end is connected to the lower tube side of the tube heat exchanger 10. The main liquid tank 12 is connected to the secondary liquid tank 18 through a connector 16, and the secondary liquid tank 18 is connected to another The device 19 is connected with the chilled water tank 28, the chilled water tank 28 is connected with the lower shell side of the tube heat exchanger 10 through the circulating water pump 29, and the upper shell side of the tube heat exchanger 10 is connected with the water distribution pipe 3; the chilled water tank 28 is provided with The heat exchange coil 23 is connected to the chiller 22 .

The spray tower 7 is provided with a manhole 5 and an observation hole 6, which are usually closed and can be opened when necessary.

The packing layer 9 in the spray tower 7 is an object with a large surface area and a small volume, that is, an object with an increased surface area that is often said in the field of engineering technology, such as Raschig rings, Boolean rings, and saddle rings.

The upper part of the main liquid separation tank 12 is provided with a solvent return pipe 13, which can return the solvent recovered and subjected to liquid separation treatment to the storage tank.

The main liquid distribution tank 12 and the secondary liquid distribution tank 18 are provided with liquid level gauges 14 and 20 for easy observation of liquid levels.

The bottoms of the main liquid separation tank 12 , the secondary liquid separation tank 18 and the chilled water tank 28 are all inverted conical structures, and drain valves 17 , 31 and 24 are connected to the bottom of the cones.

The chilled water tank 28 is provided with a float valve 26 and a ball float valve float 25, which are convenient for observing and controlling the water level of the chilled water tank.

A valve 30 is set between the inlet of the circulating water pump 28 and the chilled water tank 28, a valve 27 is set between the outlet of the circulating water pump and the chilled water tank, and a valve 8 is set between the shell side of the tube heat exchanger to facilitate various functional operations.

The spray tower 7, the tube-and-tube heat exchanger 10, the main liquid separation tank 12, the secondary liquid separation tank 18 and the chilled water tank 28 are provided with insulation layers.

The gas from the balance tank enters the main liquid separation tank 12 from the balance tank pipe 11, passes through the upper part, enters the tube side of the tube heat exchanger 10, passes through the tube tubes of the heat exchanger upwards, and meets the chilled water in the shell side from bottom to top Parallel flow heat exchange; chilled water reaches the upper part of the shell side of the tube-and-tube heat exchanger 10 upwards, enters the water distribution pipe 3 and sprays out from the holes of the water distribution pipe 3, and the water distribution pipe 3 sprays water in reverse through the holes to drive the drum 4 and the water distribution pipe 3 to automatically Spin to make the frozen water evenly disperse, sprinkle, and pass through the filler layer 9. In the packing layer 9, the updraft and the large-area downflow frozen water on the packing are directly contacted and large-area heat exchange is realized, so that the chilled water can efficiently and thoroughly absorb the heat in the gas, and the solvent vapor in it is condensed, and the precipitated gas is released from the Blower 2 extracts and evacuates.

The gas in the balance tank passes through the spray tower 7 from bottom to top, and directly contacts and exchanges heat with the sprayed and falling frozen water, so that the solvent in the gas from the balance tank is condensed.

The chilled water carrying the solvent flows back through the tube-and-tube heat exchanger 10, and directly contacts the rising exhaust gas in the tube side to exchange heat, so that the solvent vapor is condensed.

All the refrigerated water and the condensed and liquefied solvent flow into the main liquid separation tank 12. The solvent has a low density and is located in the upper part of the water layer. Observe the stratification of water and solvent through the liquid level gauge 14. If there is too much solvent, you can open the solvent on the solvent return pipe 13. The valve enables solvent reflux.

When the liquid level exceeds the position of the balance pipe of the connector 16, under the action of the connector, the water at the bottom of the main liquid distribution tank 12 will overflow to the secondary liquid distribution tank 18, and finally overflow to the frozen water tank 28, so that the two The solvent in the two liquid separator tanks overflows into the chilled water tank.

There is a heat exchange coil 23 in the chilled water tank 28, and the heat exchange coil is connected to a chiller to cool down the water in the chilled water tank. The chilled water is controlled by a valve 30 and enters the circulating water pump 29. The output can be divided into two channels, and the return flow of one channel is controlled by the valve 27. The pump sprays and stirs to strengthen the heat exchange between the coil in the chilled water tank and the water. The other route valve 8 adjusts the heat exchange chilled water circulation flow, and the float valve 26 automatically replenishes water to the appropriate liquid level.

The above are only preferred embodiments of the present invention, and do not limit the present invention in any form. Any person familiar with the art, without departing from the scope of the technical solution of the present invention, can use the technical content disclosed above to make many possible changes and modifications to the technical solution of the present invention, or modify it into an equivalent implementation of equivalent changes example. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention shall fall within the protection scope of the technical solution of the present invention.

Claims (9)

1. A device for improving the safety of the leaching workshop and reducing solvent loss, comprising an exhaust fan, a spray tower, a tube heat exchanger, a main liquid separation tank, a secondary liquid separation tank, a chilled water tank and a circulating water pump, characterized in that: The spray tower is a closed structure with upper and lower outlets. There is a packing layer inside. A water distribution pipe and a drum are arranged above the packing layer. There are holes on the water distribution pipe. The water distribution pipe sprays water through the holes to drive the drum and the water distribution pipe to spin; The upper tube side of the heater is connected to the inlet at the bottom of the spray tower, the outlet at the top of the spray tower is connected to the exhaust fan, and the outlet of the exhaust fan is connected to the exhaust port; one end of the main liquid separation tank is connected to the balance tank pipe, and the other end is connected to the lower pipe of the tube heat exchanger The main liquid separation tank is connected to the secondary liquid separation tank through a connector, the secondary liquid separation tank is connected to the chilled water tank through another connector, and the chilled water tank is connected to the lower shell side of the tube heat exchanger through a circulating water pump. The upper shell side of the heater is connected to the water distribution pipe; the chilled water tank is provided with a heat exchange coil, and the heat exchange coil is connected to the chiller. 2. The device for improving the safety of the leaching workshop and reducing solvent loss according to claim 1, characterized in that: the spray tower is provided with inspection holes and observation holes, the inspection holes and observation holes are usually closed and can be opened when necessary . 3. The device for improving the safety of the leaching workshop and reducing solvent loss according to claim 1, characterized in that: the packing layer in the spray tower is an object with a large surface area and a small volume. 4. The device for improving the safety of the leaching workshop and reducing solvent loss according to claim 1, characterized in that: the upper part of the main liquid separation tank is provided with a solvent return pipe, which can return the solvent recovered and subjected to liquid separation treatment. tank. 5. The device for improving the safety of the leaching workshop and reducing solvent loss according to claim 1, characterized in that: the main liquid distribution tank and the secondary liquid distribution tank are both equipped with liquid level gauges, which is convenient for observing the liquid level. 6. The device for improving the safety of the leaching workshop and reducing solvent loss according to claim 1, characterized in that: the bottoms of the main liquid separation tank, the secondary liquid separation tank and the frozen water tank are all inverted conical structures, and the bottom of the cone is connected There is a drain valve. 7. The device for improving the safety of the leaching workshop and reducing solvent loss according to claim 1, characterized in that: said chilled water tank is provided with a float valve and a float valve float, which is convenient for observing and controlling the water level of the chilled water tank. 8. The device for improving the safety of the leaching workshop and reducing solvent loss according to claim 1, characterized in that: between the inlet of the circulating water pump and the chilled water tank, between the outlet of the circulating water pump and the chilled water tank, and the tube heat exchanger There are valves between the shells to facilitate the realization of various functional operations. 9. The device for improving the safety of the leaching workshop and reducing solvent loss according to claim 1, characterized in that: the spray tower, the tube heat exchanger, the main liquid separation tank, the secondary liquid separation tank and the chilled water tank are equipped with There is insulation.