Novel waste heat utilization device

Abstract

The utility model relates to the technical field of evaporation and concentration, and provides a novel waste heat utilization device which comprises a multi-effect evaporation unit, a multi-separation unit, a multi-stage preheating unit, a multi-stage cooling unit, a multi-stage water condensation unit and an MVR (mechanical vapor recompression) vapor compressor, the first-effect evaporator, the second-effect evaporator, the third-effect evaporator, the fourth-effect evaporator, the fifth-effect evaporator and the sixth-effect evaporator operate in a series connection mode, and the whole set of evaporation device adopts a continuous feeding and continuous discharging production mode. Wherein the first-effect evaporator, the second-effect evaporator, the third-effect evaporator, the fourth-effect evaporator, the fifth-effect evaporator and the sixth-effect evaporator all adopt forced falling film type evaporation, heat of secondary steam generated in the evaporation and concentration process is recycled, and the problem that in the prior art, secondary steam generated in the evaporation and concentration process cannot be fully utilized is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of evaporation and concentration, and specifically to a novel waste heat utilization device. Background Art

[0002] Evaporation is a unit operation that heats the solution, partially vaporizes the solvent, and removes it from the solution to increase the solute concentration. It is usually carried out in an evaporator, which consists of a heating chamber and an evaporation chamber. The heating chamber provides the heat required for evaporation, causing the liquid to boil and vaporize, and the solvent in the evaporation chamber becomes gaseous and separates from the liquid phase, achieving evaporation concentration.

[0003] In the multiple-effect evaporator, the heating steam first enters the first effect, and the secondary steam generated by the first effect enters the second effect as heating steam. Multiple evaporators are connected in series to form multiple-effect evaporation. Since the last effect is connected to the vacuum device, the operating pressure of the evaporation chamber gradually decreases during the multiple-effect operation, and the heating steam temperature of each effect and the boiling point of the solution to be evaporated also decrease successively.

[0004] As a type of multi-effect evaporator, the five-effect evaporator is favored by people because of its effective use of steam heat. Usually, people use water vapor as a heating agent to evaporate aqueous solutions. In order to distinguish, people call the water vapor used as a heat source heating steam or primary steam, and the steam evaporated from the solution secondary steam. The evaporator is essentially a heat exchanger, in which the material exchanges heat with the heat source, so that part of the solvent becomes gaseous and separates, thereby increasing the concentration of the material and achieving evaporation and concentration. There are many types of evaporators, such as single-effect, double-effect, triple-effect, quadruple-effect and five-effect. The more effects there are, the better the energy saving effect.

[0005] After searching, the announcement number CN212308891U discloses an energy-saving five-effect evaporator, including a five-effect evaporator body, a first heat exchanger and a second heat exchanger; the low-temperature medium inlet of the first heat exchanger is connected to the feed pipe, and the low-temperature medium outlet is connected to the raw liquid inlet of the five-effect tank; the concentrated liquid outlet of the five-effect tank is connected to the low-temperature medium inlet of the second heat exchanger; the low-temperature medium outlet of the second heat exchanger is connected to the raw liquid inlet of the four-effect tank; the four-effect tank, the three-effect tank, the two-effect tank and the one-effect tank are connected in sequence; the concentrated liquid outlet of the one-effect tank is connected to the high-temperature medium inlet of the second heat exchanger; the high-temperature medium outlet of the second heat exchanger is connected to the high-temperature medium inlet of the first heat exchanger; the high-temperature medium outlet of the first heat exchanger is connected to the finished product pipe. The five-effect evaporator preheats the raw liquid with a lower temperature through the high-temperature concentrated liquid after the concentration treatment, increases the temperature of the raw liquid, further saves energy, and improves the evaporation efficiency.

[0006] However, the above-mentioned five-effect evaporator still has the following problems: the secondary steam generated in the process of evaporation and concentration in the above-mentioned five-effect evaporator cannot be fully utilized, resulting in waste of heat in the secondary steam, which in turn causes heat loss, resulting in reduced product production efficiency and increased production costs. Utility Model Content

[0007] The utility model provides a novel waste heat utilization device, which solves the problem in the prior art that secondary steam generated in the process of evaporation and concentration cannot be fully utilized.

[0008] The technical solution of the utility model is as follows: A new type of waste heat utilization device, comprising:

[0009] A multi-effect evaporation unit consisting of a first-effect evaporator, a second-effect evaporator, a third-effect evaporator, a fourth-effect evaporator, a fifth-effect evaporator and a sixth-effect evaporator connected in series in sequence;

[0010] A multiple separation unit consisting of a first gas-liquid separator, a second gas-liquid separator, a third gas-liquid separator, a fourth gas-liquid separator, a fifth gas-liquid separator, and a sixth gas-liquid separator;

[0011] A multi-stage preheating unit consisting of a primary preheater, a secondary preheater, and a tertiary preheater;

[0012] A multi-stage cooling unit consisting of a primary condenser and a secondary condenser;

[0013] A multi-stage condensation unit consisting of a primary condensation water tank and a secondary condensation water tank;

[0014] And MVR steam compressor.

[0015] Preferably, the first-effect evaporator, the second-effect evaporator, the third-effect evaporator, the fourth-effect evaporator, the fifth-effect evaporator and the sixth-effect evaporator are sequentially transported by a first-effect discharge pump, a second-effect discharge pump, a third-effect discharge pump, a fourth-effect discharge pump and a fifth-effect discharge pump, and the liquid produced by the sixth-effect evaporator is pumped out by the sixth-effect discharge pump.

[0016] Preferably, the secondary steam generated by the first-effect evaporator is separated by the first gas-liquid separator and then enters the MVR steam compressor, is compressed and heated by the MVR steam compressor, and then passes into the shell side of the first-effect evaporator as a heat source. The secondary steam generated by the second-effect evaporator, the third-effect evaporator, the fourth-effect evaporator, and the fifth-effect evaporator is separated by the second gas-liquid separator, the third gas-liquid separator, the fourth gas-liquid separator, and the fifth gas-liquid separator in sequence, and then gradiently enters the shell side of the three-effect evaporator, the four-effect evaporator, the five-effect evaporator, and the six-effect evaporator as a heat source. The secondary steam generated by the six-effect evaporator enters the sixth gas-liquid separator for separation and then enters the secondary condenser for condensation.

[0017] Preferably, the non-condensable gas generated by the first-effect evaporator is passed into a primary condenser for condensation and then discharged by a vacuum pump.

[0018] Preferably, the condensed water generated by the first-effect evaporator and the condensed water generated by the first-stage condenser are passed into a first-stage dirty condensed water tank for purification and then discharged by a condensed water pump.

[0019] Preferably, the non-condensable gas generated by the second-effect evaporator, the third-effect evaporator, the fourth-effect evaporator, the fifth-effect evaporator and the sixth-effect evaporator is passed into a secondary condenser for condensation and then discharged by a vacuum pump.

[0020] Preferably, the condensed water produced by the second-effect evaporator, the third-effect evaporator, the fourth-effect evaporator, the fifth-effect evaporator, the sixth-effect evaporator and the condensed water produced by the secondary condenser are passed into a secondary dirty condensed water tank for purification and then discharged by a condensed water pump.

[0021] Preferably, a mass flow meter is provided at the outlet for producing the feed liquid of the six-effect evaporator.

[0022] Preferably, the first-effect evaporator, the second-effect evaporator, the third-effect evaporator, the fourth-effect evaporator, the fifth-effect evaporator, and the sixth-effect evaporator are all shell-and-tube evaporators.

[0023] Preferably, part of the liquid discharged from the first-effect evaporator enters a first-stage preheater, a second-stage preheater, and a third-stage preheater in sequence for preheating, and the first-stage preheater, the second-stage preheater, and the third-stage preheater respectively pass the preheated liquid into a second-effect evaporator, a third-effect evaporator, and a fourth-effect evaporator.

[0024] The beneficial effects of the utility model are:

[0025] 1. The first-effect evaporator, the second-effect evaporator, the third-effect evaporator, the fourth-effect evaporator, the fifth-effect evaporator and the sixth-effect evaporator in the utility model are operated in series, and the whole evaporation device adopts a production mode of continuous feeding and continuous discharging, wherein the first-effect evaporator, the second-effect evaporator, the third-effect evaporator, the fourth-effect evaporator, the fifth-effect evaporator and the sixth-effect evaporator all adopt forced falling film evaporation, and the heat of the secondary steam generated in the evaporation and concentration process is reused, which solves the problem that the secondary steam generated in the evaporation and concentration process in the prior art cannot be fully utilized;

[0026] 2. The utility model adopts MVR steam compression cycle technology, which reduces pollution to the environment, meets environmental protection requirements, and has a high energy-saving effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The utility model is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0028] Figure 1This is a schematic diagram of a novel waste heat utilization device proposed by the utility model;

[0029] In the figure: 1. Multi-effect evaporation unit; 2. Multiple separation unit; 3. Multi-stage preheating unit; 4. Multi-stage cooling unit; 5. Multi-stage condensation unit; 6. MVR steam compressor. DETAILED DESCRIPTION

[0030] The following will be combined with the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0031] See also Figure 1 The utility model provides a technical solution: a new type of waste heat utilization device, which belongs to a single-effect MVR + five-effect waste heat falling film evaporator, and mainly includes six major components: a multi-effect evaporation unit 1, a multiple separation unit 2, a multi-stage preheating unit 3, a multi-stage cooling unit 4, a multi-stage condensation unit 5 and an MVR steam compressor 6.

[0032] The multi-effect evaporation unit 1 comprises a first-effect evaporator, a second-effect evaporator, a third-effect evaporator, a fourth-effect evaporator, a fifth-effect evaporator, and a sixth-effect evaporator connected in series in sequence;

[0033] The multiple separation unit 2 includes a first gas-liquid separator, a second gas-liquid separator, a third gas-liquid separator, a fourth gas-liquid separator, a fifth gas-liquid separator, and a sixth gas-liquid separator which are arranged corresponding to the first-effect evaporator, the second-effect evaporator, the third-effect evaporator, the fourth-effect evaporator, the fifth-effect evaporator, and the sixth-effect evaporator;

[0034] The multi-stage preheating unit 3 includes a primary preheater, a secondary preheater, and a tertiary preheater for feeding preheated liquid into the second-effect evaporator, the third-effect evaporator, and the fourth-effect evaporator;

[0035] The multi-stage cooling unit 4 includes a primary condenser and a secondary condenser for condensing the non-condensable gas generated by the first-effect evaporator, the second-effect evaporator, the third-effect evaporator, the fourth-effect evaporator, the fifth-effect evaporator, and the sixth-effect evaporator;

[0036] The multi-stage condensation unit 5 includes a primary dirty condensed water tank and a secondary dirty condensed water tank for purifying secondary condensed water generated by the first effect evaporator, the second effect evaporator, the third effect evaporator, the fourth effect evaporator, the fifth effect evaporator, and the sixth effect evaporator.

[0037] The first-effect evaporator, the second-effect evaporator, the third-effect evaporator, the fourth-effect evaporator, the fifth-effect evaporator and the sixth-effect evaporator are sequentially transported by the first-effect discharge pump, the second-effect discharge pump, the third-effect discharge pump, the fourth-effect discharge pump and the fifth-effect discharge pump in stages, and the liquid produced by the sixth-effect evaporator is pumped out by the sixth-effect discharge pump.

[0038] The secondary steam generated by the first-effect evaporator is separated by the first gas-liquid separator and then enters the MVR steam compressor 6. After being compressed and heated by the MVR steam compressor 6, it is passed into the shell side of the first-effect evaporator as a heat source. The secondary steam generated by the second-effect evaporator, the third-effect evaporator, the fourth-effect evaporator, and the fifth-effect evaporator is separated by the second gas-liquid separator, the third gas-liquid separator, the fourth gas-liquid separator, and the fifth gas-liquid separator in turn, and then gradually enters the shell side of the three-effect evaporator, the four-effect evaporator, the five-effect evaporator, and the six-effect evaporator as a heat source. The secondary steam generated by the six-effect evaporator enters the sixth gas-liquid separator for separation and then enters the secondary condenser for condensation.

[0039] The non-condensable gas produced by the first-effect evaporator is passed into the first-stage condenser for condensation and then discharged by the vacuum pump and passed into the first-stage condenser. The condensed water produced by the first-effect evaporator and the condensed water produced by the first-stage condenser are passed into the first-stage dirty condensed water tank for purification and then discharged by the condensed water pump to reduce pollution emissions.

[0040] The non-condensable gas produced by the second-effect evaporator, third-effect evaporator, fourth-effect evaporator, fifth-effect evaporator and sixth-effect evaporator is passed into the secondary condenser for condensation and then discharged by the vacuum pump. The condensed water produced by the second-effect evaporator, third-effect evaporator, fourth-effect evaporator, fifth-effect evaporator and sixth-effect evaporator as well as the condensed water produced by the secondary condenser are passed into the secondary dirty condensed water tank for purification and then discharged by the condensed water pump to reduce pollution emissions.

[0041] A mass flow meter is provided at the outlet of the liquid produced by the six-effect evaporator to detect the liquid in the six-effect evaporator.

[0042] The first-effect evaporator, second-effect evaporator, third-effect evaporator, fourth-effect evaporator, fifth-effect evaporator and sixth-effect evaporator are all shell-and-tube evaporators.

[0043] Part of the liquid discharged from the first-effect evaporator enters the first-stage preheater, the second-stage preheater, and the third-stage preheater in turn for preheating. The first-stage preheater, the second-stage preheater, and the third-stage preheater pass the preheated liquid into the second-effect evaporator, the third-effect evaporator, and the fourth-effect evaporator respectively.

[0044] The working process of the utility model is as follows: the material sent from the previous process is stored in the material balance tank, and is sent into the first-effect falling film evaporator by the feed pump. The material is evenly distributed to the inner wall of the tube through the distributor at the top of the first-effect falling film evaporator. The material flows downward along the inner wall of the tube and is heated. The heated material reaches the bottom lower cavity of the first-effect falling film evaporator. A small amount of foam entrainment and secondary steam enter the first gas-liquid separator for cyclone separation. The separated material returns to the bottom of the first-effect falling film evaporator and is sent into the second-effect falling film evaporator through the first-effect discharge pump. The separated secondary steam enters the MVR steam compressor 6 for compression and temperature increase. After the temperature is increased, the secondary steam is sent back to the shell side of the first-effect falling film evaporator as the heat source of the first-effect falling film evaporator. A small amount of non-condensable gas is condensed by the primary condenser.

[0045] The material is evenly distributed to the inner wall of the tubes through the distributor at the top of the two-effect falling film evaporator. The material flows downward along the inner wall of the tubes and is heated. The heated material reaches the bottom lower cavity of the two-effect falling film evaporator. A small amount of foam entrainment and secondary steam enter the second gas-liquid separator for cyclone separation. The separated material returns to the bottom of the two-effect falling film evaporator and is sent to the three-effect falling film evaporator through the two-effect discharge pump. The separated secondary steam enters the shell side of the three-effect falling film evaporator as the heat source of the three-effect falling film evaporator.

[0046] The material is evenly distributed to the inner wall of the tubes through the distributor at the top of the three-effect falling film evaporator. The material flows downward along the inner wall of the tubes and is heated. The heated material reaches the bottom lower cavity of the three-effect falling film evaporator. A small amount of foam entrainment and secondary steam enter the third gas-liquid separator for cyclone separation. The separated material returns to the bottom of the three-effect falling film evaporator and is sent to the four-effect falling film evaporator through the three-effect discharge pump. The separated secondary steam enters the shell side of the four-effect falling film evaporator as the heat source of the four-effect falling film evaporator.

[0047] The material is evenly distributed to the inner wall of the tubes through the distributor at the top of the four-effect falling film evaporator. The material flows downward along the inner wall of the tubes and is heated. The heated material reaches the bottom lower cavity of the four-effect falling film evaporator. A small amount of foam entrainment and secondary steam enter the fourth gas-liquid separator for cyclone separation. The separated material returns to the bottom of the four-effect falling film evaporator and is sent to the five-effect falling film evaporator through the four-effect discharge pump. The separated secondary steam enters the shell side of the five-effect falling film evaporator as the heat source of the five-effect falling film evaporator.

[0048] The material is evenly distributed to the inner wall of the tubes through the distributor at the top of the five-effect falling film evaporator. The material flows downward along the inner wall of the tubes and is heated. The heated material reaches the bottom lower cavity of the five-effect falling film evaporator. A small amount of foam entrainment and secondary steam enter the fifth gas-liquid separator for cyclone separation. The separated material returns to the bottom of the five-effect falling film evaporator and is sent to the six-effect falling film evaporator through the five-effect discharge pump. The separated secondary steam enters the shell side of the six-effect falling film evaporator as the heat source of the six-effect falling film evaporator.

[0049] The material is evenly distributed to the inner wall of the tube through the distributor at the top of the six-effect falling film evaporator. The material flows downward along the inner wall of the tube and is heated. The heated material reaches the bottom lower cavity of the six-effect falling film evaporator. A small amount of foam entrainment and secondary steam enter the sixth gas-liquid separator for cyclone separation. The separated material returns to the bottom of the six-effect falling film evaporator and is tested for concentration by the mass flow meter. It is sent out by the six-effect discharge pump through the automatic valve. The separated secondary steam enters the secondary condenser for condensation.

[0050] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A new type of waste heat utilization device, characterized in that: include: A multi-effect evaporation unit (1) is composed of a first-effect evaporator, a second-effect evaporator, a third-effect evaporator, a fourth-effect evaporator, a fifth-effect evaporator, and a sixth-effect evaporator connected in series in sequence; A multiple separation unit (2) consisting of a first gas-liquid separator, a second gas-liquid separator, a third gas-liquid separator, a fourth gas-liquid separator, a fifth gas-liquid separator, and a sixth gas-liquid separator; A multi-stage preheating unit (3) consisting of a primary preheater, a secondary preheater, and a tertiary preheater; A multi-stage cooling unit (4) consisting of a primary condenser and a secondary condenser; A multi-stage condensation unit (5) consisting of a primary condensation water tank and a secondary condensation water tank; and an MVR steam compressor (6); The secondary steam generated by the first-effect evaporator is separated by the first gas-liquid separator and then enters the MVR steam compressor (6), is compressed and heated by the MVR steam compressor (6), and then enters the shell side of the first-effect evaporator as a heat source. The secondary steam generated by the second-effect evaporator, the third-effect evaporator, the fourth-effect evaporator, and the fifth-effect evaporator are separated by the second gas-liquid separator, the third gas-liquid separator, the fourth gas-liquid separator, and the fifth gas-liquid separator in sequence, and then enters the shell side of the third-effect evaporator, the fourth-effect evaporator, and the sixth-effect evaporator in a gradient manner as a heat source. The secondary steam generated by the sixth-effect evaporator enters the sixth gas-liquid separator for separation and then enters the secondary condenser for condensation.

2. A novel waste heat utilization device according to claim 1, characterized in that: The first-effect evaporator, the second-effect evaporator, the third-effect evaporator, the fourth-effect evaporator, the fifth-effect evaporator and the sixth-effect evaporator are sequentially connected by a first-effect discharge pump, a second-effect discharge pump, a third-effect discharge pump, a fourth-effect discharge pump and a fifth-effect discharge pump to convey the feed liquid in stages, and the feed liquid produced by the sixth-effect evaporator is pumped out by the sixth-effect discharge pump.

3. A novel waste heat utilization device according to claim 1, characterized in that: The non-condensable gas generated by the first-effect evaporator is passed into the first-stage condenser for condensation and then discharged by the vacuum pump.

4. A novel waste heat utilization device according to claim 3, characterized in that: The condensed water generated by the first-effect evaporator and the condensed water generated by the first-stage condenser are passed into a first-stage dirty condensed water tank for purification and then discharged by a condensed water pump.

5. A novel waste heat utilization device according to claim 1, characterized in that: The non-condensable gas generated by the second-effect evaporator, the third-effect evaporator, the fourth-effect evaporator, the fifth-effect evaporator and the sixth-effect evaporator is passed into the secondary condenser for condensation and then discharged by the vacuum pump.

6. A novel waste heat utilization device according to claim 5, characterized in that: The condensed water produced by the second-effect evaporator, the third-effect evaporator, the fourth-effect evaporator, the fifth-effect evaporator and the sixth-effect evaporator and the condensed water produced by the secondary condenser are passed into the secondary dirty condensed water tank for purification and then discharged by the condensed water pump.

7. A novel waste heat utilization device according to claim 1, characterized in that: The outlet for producing feed liquid of the six-effect evaporator is provided with a mass flow meter.

8. A novel waste heat utilization device according to claim 1, characterized in that: The first-effect evaporator, the second-effect evaporator, the third-effect evaporator, the fourth-effect evaporator, the fifth-effect evaporator and the sixth-effect evaporator are all shell-and-tube evaporators.

9. A novel waste heat utilization device according to claim 1, characterized in that: Part of the liquid discharged from the first-effect evaporator enters the first-stage preheater, the second-stage preheater, and the third-stage preheater in sequence for preheating. The first-stage preheater, the second-stage preheater, and the third-stage preheater respectively pass the preheated liquid into the second-effect evaporator, the third-effect evaporator, and the fourth-effect evaporator.

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