阅读说明：本技术 三效蒸发装置及方法 (Triple-effect evaporation device and method ) 是由 王斌 霍增辉 杨德生 尚惠平 孙吉全 徐纲 徐鹏 王波 王英普 于 2019-10-24 设计创作，主要内容包括：本发明公开了一种三效蒸发装置及方法,其中三效蒸发装置包括一效蒸发器、二效蒸发器和三效蒸发器,还包括换热器,换热器的冷流体侧的入口与物料管连接,换热器的冷流体侧的出口与所述一笑蒸发器的第一再沸器的冷流体侧的入口连接,所述换热器的热流体侧的入口与所述一效蒸发器的第一再沸器的热流体侧的出口、第一冷凝液罐和第二冷凝液罐连接,以使所述第一再沸器、所述第一冷凝液罐和所述第二冷凝液罐能够单独或任意组合提供冷凝液作为所述换热器的热源对所述换热器冷流体侧的物料进行预热。本发明能够降低蒸汽消耗。(The invention discloses a triple-effect evaporation device and a triple-effect evaporation method, wherein the triple-effect evaporation device comprises a first-effect evaporator, a second-effect evaporator, a triple-effect evaporator and a heat exchanger, an inlet on the cold fluid side of the heat exchanger is connected with a material pipe, an outlet on the cold fluid side of the heat exchanger is connected with an inlet on the cold fluid side of a first reboiler of the first-effect evaporator, an inlet on the hot fluid side of the heat exchanger is connected with an outlet on the hot fluid side of the first reboiler of the first-effect evaporator, a first condensate tank and a second condensate tank, so that the first reboiler, the first condensate tank and the second condensate tank can be independently or randomly combined to provide condensate as a heat source of the heat exchanger to preheat materials on the cold fluid side of the heat exchanger. The invention can reduce steam consumption.)

1. A triple effect evaporation apparatus, comprising:

the inlet of the cold fluid side of the first reboiler is connected with a material pipe, and the heating medium of the hot fluid side of the first reboiler heats the material of the cold fluid side through heat exchange;

a first evaporator connected to the inlet and outlet of the cold fluid side of the first reboiler for cyclically heating the material in the first evaporator through the first reboiler;

a second reboiler, wherein the inlet of the heat fluid side of the second reboiler is connected with the top of the first evaporation tower, and the steam of the first evaporation tower is used as the heat source of the second reboiler;

a second evaporation tower which is connected with an inlet and an outlet of the cold fluid side of the second reboiler so as to circularly heat the material in the second evaporation tower through the second reboiler, and the first evaporation tower is connected with an inlet of the cold fluid side of the second reboiler so as to convey the material in the first evaporation tower to the cold fluid side of the second reboiler for heat exchange;

a first condensate tank connected to an outlet of the second reboiler on the hot fluid side, the first condensate tank being configured to accommodate condensate generated on the hot fluid side of the second reboiler;

a third reboiler, wherein an inlet on the hot fluid side of the third reboiler is connected with the top of the second evaporation tower, steam of the second evaporation tower is used as a heat source of the third reboiler, and the second evaporation tower is connected with an inlet on the cold fluid side of the third reboiler so as to convey materials in the second evaporation tower to the cold fluid side of the third reboiler for heat exchange;

a third evaporation tower connected with the inlet and the outlet of the cold fluid side of the third reboiler for circularly heating the material in the third evaporation tower through the third reboiler;

a second condensate tank connected to an outlet of the hot fluid side of the third reboiler, the second condensate tank being configured to accommodate condensate generated on the hot fluid side of the third reboiler;

and the inlet on the cold fluid side of the heat exchanger is connected with the material pipe, the outlet on the cold fluid side of the heat exchanger is connected with the inlet on the cold fluid side of the first reboiler, and the inlet on the hot fluid side of the heat exchanger is connected with the outlet on the hot fluid side of the first reboiler, the first condensate tank and the second condensate tank, so that the first reboiler, the first condensate tank and the second condensate tank can provide condensate alone or in any combination to be used as a heat source of the heat exchanger to preheat the material on the cold fluid side of the heat exchanger.

2. The triple-effect evaporation device of claim 1, further comprising a first cooler connected to the top of the third evaporation tower for cooling the vapor of the third evaporation tower.

3. The triple-effect evaporation device of claim 2, further comprising a condensate sump connected to the condensate outlet of the first cooler for receiving condensate formed by the vapor cooling of the third evaporation tower.

4. A triple effect evaporation device according to claim 3, wherein the condensate tank is further connected to a hot fluid side outlet of the heat exchanger, so that the condensate tank can receive condensate after heat exchange by the heat exchanger;

the condensate tank is further connected with a hot fluid side outlet of the first reboiler so that the condensate tank can receive condensate of the first reboiler;

the condensate tank is also connected with the first condensate tank so that the condensate tank can receive condensate of the first condensate tank;

the condensate tank is also connected with the second condensate tank so that the condensate tank can receive condensate of the second condensate tank.

5. The triple-effect evaporation device according to claim 3 or 4, further comprising a second condensate pump and a second cooler, wherein a hot fluid side inlet of the second cooler is connected with the condensate tank through the second condensate pump, a hot fluid side outlet of the second cooler is connected with the first evaporation tower, the second evaporation tower and the third evaporation tower, and condensate in the condensate tank can flow back to the first evaporation tower, the second evaporation tower and the third evaporation tower after passing through the second cooler.

6. The triple-effect evaporation device according to claim 1, further comprising a first condensate pump, wherein the first condensate tank and the second condensate tank are respectively connected to an input end of the first condensate pump, an output end of the first condensate pump is connected to a hot fluid side inlet of the heat exchanger, and the first condensate pump can convey condensate of the first condensate tank and/or the second condensate tank as a heat source of the heat exchanger to preheat a material on a cold fluid side of the heat exchanger.

7. A method of triple effect evaporation, comprising:

the first reboiler heats the material and then conveys the material to the first evaporation tower;

part of water in the material is evaporated to form steam, and the steam is output to a second reboiler from the top of the first evaporation tower and is used as a heat source of the second reboiler;

the material in the first evaporation tower is conveyed to the cold fluid side of the second reboiler for heat exchange;

the second reboiler heats the materials and then conveys the materials to a second evaporation tower;

partial water in the material is evaporated to form steam, and the steam is output to a third reboiler from the top of the second evaporation tower and is used as a heat source of the third reboiler;

the first condensate tank contains condensate generated on the hot fluid side of the second reboiler;

the material in the second evaporation tower is conveyed to the cold fluid side of the third reboiler for heat exchange;

the third reboiler heats the materials and then conveys the materials to the third evaporation tower;

partial evaporation of water in the material forms steam, and the steam is output from the top of the third evaporation tower;

the second condensate tank contains condensate generated on the hot fluid side of the third reboiler;

the first reboiler, the first condensate tank and the second condensate tank are independently or randomly combined to provide condensate as a heat source of the heat exchanger, and the material on the cold fluid side of the heat exchanger is preheated and then conveyed to the cold fluid side of the first reboiler for heating.

8. The triple effect evaporation method of claim 7, further comprising:

the first cooler cools the vapor of the third evaporation tower;

the condensate tank contains condensate formed by cooling the steam of the third evaporation tower;

and conveying the condensate of the first condensate tank and/or the second condensate tank through a first condensate pump, and preheating the material on the cold fluid side of the heat exchanger as a heat source of the heat exchanger.

9. The triple effect evaporation method of claim 8, further comprising:

the condensate tank can receive condensate after heat exchange of the heat exchanger;

the condensate tank is capable of receiving condensate from the first reboiler;

the condensate tank is capable of receiving condensate of the first condensate tank;

the condensate tank is capable of receiving condensate from the second condensate tank.

10. A triple effect evaporation method according to claim 8 or 9, further comprising:

after the condensate in the condensate tank passes through the second cooler, part of the condensate can flow back to the first evaporation tower, the second evaporation tower and the third evaporation tower.

Technical Field

The invention relates to the technical field of triple-effect evaporation, in particular to a triple-effect evaporation device and method.

Background

The triple-effect evaporation device is an extraction and concentration device, adopts a shell and tube circulating external heating working principle, has short physical heating time, high evaporation speed and large concentration ratio, effectively keeps the original effect of materials, has obvious energy-saving effect, and is widely suitable for the evaporation and concentration process of liquid materials in pharmacy, chemical industry, food, light industry and the like.

However, the existing triple-effect evaporation has the problems of high steam consumption and condensate consumption, and high running cost of the triple-effect evaporation due to the waste of heat of condensate.

Disclosure of Invention

In view of the above problems in the prior art, embodiments of the present invention provide a triple-effect evaporation apparatus and method, which can reduce the consumption of triple-effect evaporation steam.

In order to solve the above technical problem, an embodiment of the present invention provides a triple-effect evaporation apparatus, including:

the inlet of the cold fluid side of the first reboiler is connected with a material pipe, and the heating medium of the hot fluid side of the first reboiler heats the material of the cold fluid side through heat exchange;

a first evaporator connected to the inlet and outlet of the cold fluid side of the first reboiler for cyclically heating the material in the first evaporator through the first reboiler;

a second reboiler, wherein the inlet of the heat fluid side of the second reboiler is connected with the top of the first evaporation tower, and the steam of the first evaporation tower is used as the heat source of the second reboiler;

a second evaporation tower which is connected with an inlet and an outlet of the cold fluid side of the second reboiler so as to circularly heat the material in the second evaporation tower through the second reboiler, and the first evaporation tower is connected with an inlet of the cold fluid side of the second reboiler so as to convey the material in the first evaporation tower to the cold fluid side of the second reboiler for heat exchange;

a first condensate tank connected to an outlet of the second reboiler on the hot fluid side, the first condensate tank being configured to accommodate condensate generated on the hot fluid side of the second reboiler;

a third reboiler, wherein an inlet on the hot fluid side of the third reboiler is connected with the top of the second evaporation tower, steam of the second evaporation tower is used as a heat source of the third reboiler, and the second evaporation tower is connected with an inlet on the cold fluid side of the third reboiler so as to convey materials in the second evaporation tower to the cold fluid side of the third reboiler for heat exchange;

a third evaporation tower connected with the inlet and the outlet of the cold fluid side of the third reboiler for circularly heating the material in the third evaporation tower through the third reboiler;

a second condensate tank connected to an outlet of the hot fluid side of the third reboiler, the second condensate tank being configured to accommodate condensate generated on the hot fluid side of the third reboiler;

and the inlet on the cold fluid side of the heat exchanger is connected with the material pipe, the outlet on the cold fluid side of the heat exchanger is connected with the inlet on the cold fluid side of the first reboiler, and the inlet on the hot fluid side of the heat exchanger is connected with the outlet on the hot fluid side of the first reboiler, the first condensate tank and the second condensate tank, so that the first reboiler, the first condensate tank and the second condensate tank can provide condensate alone or in any combination to be used as a heat source of the heat exchanger to preheat the material on the cold fluid side of the heat exchanger.

Optionally, the triple-effect evaporation device further comprises a first cooler, and the first cooler is connected with the top of the third evaporation tower to cool the steam of the third evaporation tower.

Optionally, the triple-effect evaporation device further comprises a condensate tank, which is connected to the condensate outlet of the first cooler and is used for accommodating condensate formed by cooling the steam of the third evaporation tower.

Optionally, the condensate tank is further connected with a hot fluid side outlet of the heat exchanger, so that the condensate tank can receive condensate after heat exchange by the heat exchanger;

the condensate tank is further connected with a hot fluid side outlet of the first reboiler so that the condensate tank can receive condensate of the first reboiler;

the condensate tank is also connected with the first condensate tank so that the condensate tank can receive condensate of the first condensate tank;

the condensate tank is also connected with the second condensate tank so that the condensate tank can receive condensate of the second condensate tank.

Optionally, the triple-effect evaporation device further includes a second condensate pump and a second cooler, a hot fluid side inlet of the second cooler is connected to the condensate tank through the second condensate pump, a hot fluid side outlet of the second cooler is connected to the first evaporation tower, the second evaporation tower and the third evaporation tower, and condensate in the condensate tank can flow back to the first evaporation tower, the second evaporation tower and the third evaporation tower after passing through the second cooler.

Optionally, the triple-effect evaporation device further includes a first condensate pump, the first condensate tank and the second condensate tank are respectively connected to an input end of the first condensate pump, an output end of the first condensate pump is connected to a hot fluid side inlet of the heat exchanger, and the first condensate pump can convey condensate of the first condensate tank and/or the second condensate tank as a heat source of the heat exchanger to preheat a material on a cold fluid side of the heat exchanger.

The embodiment of the invention also provides a triple-effect evaporation method, which comprises the following steps:

the first reboiler heats the material and then conveys the material to the first evaporation tower;

part of water in the material is evaporated to form steam, and the steam is output to a second reboiler from the top of the first evaporation tower and is used as a heat source of the second reboiler;

the material in the first evaporation tower is conveyed to the cold fluid side of the second reboiler for heat exchange;

the second reboiler heats the materials and then conveys the materials to a second evaporation tower;

partial water in the material is evaporated to form steam, and the steam is output to a third reboiler from the top of the second evaporation tower and is used as a heat source of the third reboiler;

a first condensate tank contains condensate generated on the hot fluid side of the second reboiler;

the material in the second evaporation tower is conveyed to the cold fluid side of the third reboiler for heat exchange;

the third reboiler heats the materials and then conveys the materials to a third evaporation tower;

partial water in the material is evaporated to form steam which is output from the top of the third evaporation tower;

a second condensate tank contains condensate generated on the hot fluid side of the third reboiler;

the first reboiler, the first condensate tank and the second condensate tank are independently or randomly combined to provide condensate as a heat source of the heat exchanger, and the material on the cold fluid side of the heat exchanger is preheated and then conveyed to the cold fluid side of the first reboiler for heating.

Optionally, the triple-effect evaporation method further comprises:

the first cooler cools the vapor of the third evaporation tower;

the condensate tank contains condensate formed by cooling the steam of the third evaporation tower;

and conveying the condensate of the first condensate tank and/or the second condensate tank through a first condensate pump, and preheating the material on the cold fluid side of the heat exchanger as a heat source of the heat exchanger.

Optionally, the triple-effect evaporation method further comprises:

the condensate tank can receive condensate after heat exchange of the heat exchanger;

the condensate tank is capable of receiving condensate from the first reboiler;

the condensate tank is capable of receiving condensate of the first condensate tank;

the condensate tank is capable of receiving condensate from the second condensate tank.

Optionally, the triple-effect evaporation method further comprises:

after the condensate in the condensate tank passes through the second cooler, part of the condensate can flow back to the first evaporation tower, the second evaporation tower and the third evaporation tower.

The invention has the beneficial effects that: the triple-effect evaporation device and the triple-effect evaporation method can recover the heat of triple-effect evaporation condensate, preheat materials, improve the triple-effect feeding temperature, greatly save steam consumption in large-scale industrial production, reduce the consumption of a coolant of the whole system and greatly reduce the running cost of triple-effect evaporation.

Drawings

Fig. 1 is a schematic structural diagram of a triple-effect evaporation apparatus according to an embodiment of the present invention.

Detailed Description

In order that those skilled in the art will better understand the present invention, the following detailed description of the embodiments of the present invention refers to the accompanying drawings, but the present invention is not limited thereto.

Fig. 1 is a schematic structural diagram of a triple-effect evaporation apparatus according to an embodiment of the present invention. As shown in fig. 1, the present invention discloses a triple-effect evaporation apparatus, comprising:

the inlet of the cold fluid side of the first reboiler 1 is connected with a material pipe, and the heating medium of the hot fluid side of the first reboiler 1 heats the material of the cold fluid side through heat exchange;

a first evaporation tower 2 connected to the inlet and outlet of the cold fluid side of the first reboiler 1 to circularly heat the material in the first evaporation tower 2 through the first reboiler 1;

a second reboiler 3, an inlet of a heat fluid side of which is connected with the top of the first evaporation tower 2, and steam of the first evaporation tower 2 is used as a heat source of the second reboiler 3;

the second evaporation tower 5 is connected with the inlet and the outlet of the cold fluid side of the second reboiler 3 so as to circularly heat the material in the second evaporation tower 5 through the second reboiler 3, and the first evaporation tower 2 is connected with the inlet of the cold fluid side of the second reboiler 3 so as to convey the material in the first evaporation tower 2 to the cold fluid side of the second reboiler 3 for heat exchange;

a first condensate tank 4 connected with an outlet of the hot fluid side of the second reboiler 3, wherein the first condensate tank 4 is used for accommodating condensate generated by the hot fluid side of the second reboiler 3;

a third reboiler 6, wherein an inlet on the hot fluid side of the third reboiler 6 is connected with the top of the second evaporation tower 5, steam of the second evaporation tower 5 is used as a heat source of the third reboiler 6, and the second evaporation tower 5 is connected with an inlet on the cold fluid side of the third reboiler 6, so that the material in the second evaporation tower 5 is conveyed to the cold fluid side of the third reboiler 6 for heat exchange;

a third evaporation tower 8 which is connected with the inlet and the outlet of the cold fluid side of the third reboiler 6 so as to circularly heat the material in the third evaporation tower 8 through the third reboiler 6;

a second condensate tank 7 connected to an outlet of the hot fluid side of the third reboiler 6, the second condensate tank 7 being configured to accommodate condensate generated on the hot fluid side of the third reboiler 6;

and the inlet of the heat exchanger 15 on the cold fluid side is connected with the material pipe, the outlet of the cold fluid side is connected with the inlet of the cold fluid side of the first reboiler 1, and the inlet of the hot fluid side of the heat exchanger 15 is connected with the outlet of the hot fluid side of the first reboiler 1, the first condensate tank 4 and the second condensate tank 7, so that the first reboiler 1, the first condensate tank 4 and the second condensate tank 7 can provide condensate alone or in any combination to be used as a heat source of the heat exchanger 15 to preheat the material on the cold fluid side of the heat exchanger.

The triple-effect evaporation device comprises a single-effect evaporator, a double-effect evaporator and a triple-effect evaporator. Wherein the first effect evaporator comprises a first reboiler 1 and a first evaporation tower 2, the second effect evaporator comprises a second reboiler 3 and a second evaporation tower 5, and the third effect evaporator comprises a third reboiler 6 and a third evaporation tower 8. The first condensate tank 4 is used for accommodating condensate of the first evaporation tower 2 (generated after heat exchange of the second reboiler 3, and is called three-effect one-tower condensate for short). The second condensate tank 7 is used for accommodating condensate of the second evaporation tower 5 (generated after heat exchange of the third reboiler 6, and referred to as three-effect two-tower condensate for short). In the embodiment of the invention, one or any combination of condensate generated by the first reboiler 1, condensate generated by the three-effect first tower and condensate generated by the three-effect second tower can be used as a heat source to preheat the material, and the preheated material enters the first reboiler 1 to be heated. The embodiment of the invention can recover the heat of triple-effect evaporation condensate, preheat the material, improve the triple-effect feeding temperature, greatly save the steam consumption in the large-scale industrial production, reduce the coolant consumption of the whole system and greatly reduce the running cost of triple-effect evaporation.

In the embodiment of the invention, the first reboiler 1, the first condensate tank 4 and the second condensate tank 7 can independently provide condensate as a heat source of the heat exchanger 15 to preheat the material on the cold fluid side of the heat exchanger. For example, the triple effect one column condensate serves as a heat source for triple effect feeding, and the triple effect one column feeding temperature is increased. Or the condensate of the three-effect two-tower is used as a heat source of three-effect feeding, and the feeding temperature of the three-effect one-tower is increased. Or the condensate generated by the first reboiler 1 is used as a heat source of the feeding of the three-effect one-tower, so that the feeding temperature of the three-effect one-tower is increased.

In the embodiment of the present invention, the first reboiler 1, the first condensate tank 4, and the second condensate tank 7 may be optionally combined to provide condensate as a heat source of the heat exchanger 15 to preheat the material on the cold fluid side of the heat exchanger. For example, the triple-effect one-tower condensate and the double-tower condensate are used as a heat source of triple-effect feeding together, and the feed temperature of the triple-effect one-tower is increased.

In some embodiments, the triple-effect evaporation device further comprises a first condensate pump 12, the first condensate tank 4 and the second condensate tank 7 are respectively connected with an input end of the first condensate pump 12, an output end of the first condensate pump 12 is connected with a hot fluid side inlet of the heat exchanger 15, and the first condensate pump 12 can convey condensate of the first condensate tank 4 and/or the second condensate tank 7 as a heat source of the heat exchanger 15 to preheat a material on a cold fluid side of the heat exchanger 15. Through setting up first condensate pump 12, guaranteed that the condensate carries out stable preheating as the heat source to the material.

In some embodiments, the triple-effect evaporation apparatus further comprises a first cooler 9, and the first cooler 9 is connected with the top of the third evaporation tower 8 to cool the vapor of the third evaporation tower 8. The non-condensable gas can enter a vacuum system for vacuumizing operation.

In some embodiments, the triple-effect evaporation apparatus further comprises a condensate tank 11, and the condensate tank 11 is connected with the condensate outlet of the first cooler 9 and is used for accommodating condensate formed by steam cooling of the third evaporation tower 8.

In some embodiments, the condensate tank 11 is further connected to a hot fluid side outlet of the heat exchanger 15, so that the condensate tank 11 can receive the condensate after heat exchange by the heat exchanger 15. When condensate generated by the first reboiler 1, triple-effect first-tower condensate or triple-effect second-tower condensate is used as a heat source to enter the heat exchanger 15 to preheat materials, the condensate enters the condensate tank 11.

In some embodiments, the condensate tank 11 is also connected to the hot fluid side outlet of the first reboiler 1, so that the condensate tank 11 can receive the condensate of the first reboiler. When the condensate generated by the first reboiler 1 does not serve as a heat source and enters the heat exchanger 15 to preheat the material, the condensate can directly enter the condensate tank 11, and can also be sent to downstream or other processes.

In some embodiments, the condensate tank 11 is further connected to the first condensate tank 4, so that the condensate tank 11 can receive condensate of the first condensate tank 4. When the condensate of the three-effect one-tower is not used as a heat source and enters the heat exchanger 15 to preheat the material, the condensate can directly enter the condensate tank 11.

In some embodiments, the condensate tank 11 is further connected to the second condensate tank 7, such that the condensate tank 11 is capable of receiving condensate of the second condensate tank 7. When the triple-effect two-tower condensate does not serve as a heat source and enters the heat exchanger 15 to preheat materials, the triple-effect two-tower condensate can directly enter the condensate tank 11.

In some embodiments, the triple-effect evaporation apparatus further includes a second condensate pump 13 and a second cooler 14, a hot fluid side inlet of the second cooler 14 is connected to the condensate tank 11 through the second condensate pump 13, a hot fluid side outlet of the second cooler 14 is connected to the first evaporation tower 2, the second evaporation tower 3 and the third evaporation tower 8, and condensate in the condensate tank 11 can flow back to the first evaporation tower 2, the second evaporation tower 3 and the third evaporation tower 8 after passing through the second cooler 14. After the condensate in the condensate tank 11 passes through the second cooler 14, a part of the condensate can be used as a three-effect reflux, and a part of the condensate is sent to the subsequent process.

In the embodiment of the invention, the high-purity solute at the bottom of the third evaporation tower 8 is sent to the subsequent step by the transfer pump 10.

The embodiment of the invention also provides a triple-effect evaporation method which can be realized by the triple-effect evaporation device in any embodiment. Embodiments of the apparatus described above may be used to understand the context of the methods described below. The following method can also be used to understand the working principle of the above device. Referring to fig. 1, the triple effect evaporation method includes:

the first reboiler 1 heats the material and then conveys the material to the first evaporation tower 2;

part of water in the material is evaporated to form steam, and the steam is output to the second reboiler 3 from the top of the first evaporation tower 2 and is used as a heat source of the second reboiler 3;

the material in the first evaporation tower 2 is conveyed to the cold fluid side of the second reboiler 3 for heat exchange;

the second reboiler 3 heats the materials and then conveys the materials to a second evaporation tower 5;

partial water in the material is evaporated to form steam, and the steam is output to a third reboiler 6 from the top of the second evaporation tower 5 and is used as a heat source of the third reboiler 6;

the first condensate tank 4 contains condensate generated on the hot fluid side of the second reboiler 3;

the material in the second evaporation tower 5 is conveyed to the cold fluid side of a third reboiler 6 for heat exchange;

the third reboiler 6 heats the materials and then conveys the materials to a third evaporation tower 8;

partial water in the material is evaporated to form steam which is output from the top of the third evaporation tower 8;

the second condensate tank 7 contains condensate generated on the hot fluid side of the third reboiler 8;

the first reboiler 2, the first condensate tank 4 and the second condensate tank 7 are used for providing condensate as a heat source of the heat exchanger 15 singly or in any combination, and materials on the cold fluid side of the heat exchanger 15 are preheated and then conveyed to the cold fluid side of the first reboiler 1 for heating.

In the embodiment of the invention, one or any combination of condensate generated by the first reboiler 1, condensate generated by the three-effect first tower and condensate generated by the three-effect second tower can be used as a heat source to preheat the material, and the preheated material enters the first reboiler 1 to be heated. The embodiment of the invention can recover the heat of triple-effect evaporation condensate, preheat the material, improve the triple-effect feeding temperature, greatly save the steam consumption in the large-scale industrial production, reduce the coolant consumption of the whole system and greatly reduce the running cost of triple-effect evaporation.

In some embodiments, the method further comprises: the first cooler 9 cools the vapor of the third evaporation tower 8. The non-condensable gas can enter a vacuum system for vacuumizing operation.

In some embodiments, the method further comprises: the condensate tank 11 accommodates condensate formed by the vapor cooling of the third evaporation tower 8.

In some embodiments, the method further comprises: the condensate tank 11 can receive the condensate after heat exchange by the heat exchanger 15. When condensate generated by the first reboiler 1, triple-effect first-tower condensate or triple-effect second-tower condensate is used as a heat source to enter the heat exchanger 15 to preheat materials, the condensate enters the condensate tank 11.

In some embodiments, the method further comprises: the condensate tank 11 can receive the condensate of the first reboiler 1. When the condensate generated by the first reboiler 1 does not serve as a heat source and enters the heat exchanger 15 to preheat the material, the condensate can directly enter the condensate tank 11, and can also be sent to downstream or other processes.

In some embodiments, the method further comprises: the condensate tank 11 is capable of receiving condensate of the first condensate tank 4. When the condensate of the three-effect one-tower is not used as a heat source and enters the heat exchanger 15 to preheat the material, the condensate can directly enter the condensate tank 11.

In some embodiments, the method further comprises: the condensate tank 11 is capable of receiving condensate of the second condensate tank 7. When the triple-effect two-tower condensate does not serve as a heat source and enters the heat exchanger 15 to preheat materials, the triple-effect two-tower condensate can directly enter the condensate tank 11.

In some embodiments, the method further comprises: after the condensate in the condensate tank 11 is cooled by the second cooler 14, part of the condensate can flow back to the first evaporation tower 2, the second evaporation tower 5 and the third evaporation tower 8. After the condensate in the condensate tank 11 is cooled, a part of the cooled condensate can be used as a three-effect reflux, and a part of the cooled condensate is sent to the subsequent step.

In some embodiments, the method further comprises: condensate of the first condensate tank 4 and/or the second condensate tank 7 is conveyed by the first condensate pump 12 and used as a heat source of the heat exchanger 15 to preheat materials on the cold fluid side of the heat exchanger 15. The condensate is ensured to be used as a heat source to stably preheat the material.

The following describes the three-way evaporation apparatus and method of the present invention in the embodiment of the present invention, taking the concentration of aqueous caprolactam solution as an example.

Referring also to FIG. 1, an aqueous caprolactam solution having a concentration of 30% and a temperature of about 90 ℃ from the hydrogenation system is fed to the bottom of the first reboiler 1 of the first evaporation column 2, and a part of the water is evaporated by the steam of the first reboiler 1. The water vapor evaporated enters a second reboiler 3 of a second evaporation tower 5 through the top of the first evaporation tower 2 to be used as a heat source, and the caprolactam water solution is sent to the bottom of the second reboiler 3 of the second evaporation tower 5 by controlling the liquid level of the first evaporation tower 2 and utilizing pressure difference. The pressure at the top of the first evaporation tower 2 is 278Kpa (absolute pressure), the operation temperature is 136 ℃ at the top temperature and 132 ℃ at the top temperature, and the concentration of the caprolactam water solution sent out from the bottom of the first evaporation tower is about 39 percent.

The aqueous caprolactam solution from the first evaporation column 2 is fed to the bottom of the second reboiler 3 of the second evaporation column 5 where part of the water is evaporated. The evaporated water vapor enters a third reboiler 6 of a third evaporation tower 8 through the top of the second evaporation tower 5 to be used as a heat source, and the caprolactam water solution is sent to the bottom of the third reboiler 6 by utilizing pressure difference through controlling the liquid level of the kettle of the second evaporation tower 5. The operation temperature of the second evaporation tower 5 is controlled to be 113 ℃ of kettle temperature, 107 ℃ of top temperature, the pressure at the top of the tower is about 132Kpa (absolute pressure), the concentration of the discharged materials at the bottom of the tower is 54 percent, the hexane discharged from the bottom of the second evaporation tower 5 flows into the bottom of the third reboiler 6, and the steam from the top of the second evaporation tower 5 is used as the heat source of the third reboiler 6. The operation temperature of the third evaporation tower 8 is 77 ℃ of kettle temperature, 56 ℃ of top temperature and 16.5Kpa (absolute pressure) of top pressure, and the vacuum degree at the top of the tower is controlled by a vacuum system. The bottom liquid of the third evaporation tower 8 contains caprolactam about 90%, and is sent to the next step by a conveying pump 10. The water vapor evaporated by the third reboiler 6 enters the first cooler 9 through the top of the third evaporation tower 8 for condensation, the condensate enters the condensate tank 11, the condensate in the condensate tank 11 is cooled by the second cooler 14, and then a part of the condensate is used as triple effect reflux, and a part of the condensate is sent to the subsequent step. High-temperature condensate in the first condensate tank 4 and the second condensate tank 7 is pumped to the heat exchanger 15 through the first condensate pump 12 and exchanges heat with low-temperature solute aqueous solution (material) needing to be concentrated in the heat exchanger 15, the condensate after heat exchange enters the condensate tank 11, and the solute aqueous solution after heat exchange enters the first reboiler 1 to improve the triple-effect feeding temperature.

The above embodiments are only exemplary embodiments of the present invention, and are not intended to limit the present invention, and the scope of the present invention is defined by the claims. Various modifications and equivalents may be made by those skilled in the art within the spirit and scope of the present invention, and such modifications and equivalents should also be considered as falling within the scope of the present invention.