Device for recovering condensate from methanol production process

Abstract

The utility model discloses a device for recovering condensate from a methanol production process, which comprises a first heat exchanger, a first separator, a second heat exchanger, a second separator, a third heat exchanger and a third separator which are communicated in sequence, condensate outlets at the bottoms of the first separator, the second separator and the third separator converge through pipelines and are communicated with a stripping tower, the bottom of the stripping tower is communicated with an air blower, an air inlet of the air blower is communicated with a waste nitrogen discharge port, and a liquid outlet at the bottom of the stripping tower is communicated with a condensate pump. And the other end of the condensate pump is communicated with a condensate air cooler. According to the utility model, the air blower is utilized to introduce air separation waste nitrogen at the lower part of the stripping tower to carry out reverse heat exchange on the condensate, and then the nitrogen is discharged from a diffusing port at the top of the tower; and liquid in the tower is conveyed to a condensate air cooler by using a condensate pump for heat exchange and cooling to about 30-35 DEG C, and is conveyed to each unit to be used as replenished water of the air cooler, so that the utilization rate of the condensate is improved, and the use amount of demineralized water is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of recycling condensate in methanol production process gas, in particular to a device for recycling condensate from a methanol production process. Background Art

[0002] At present, the methanol production industry needs to add medium-pressure steam due to process needs. Its role is to control the water-carbon ratio, which helps to improve the conversion rate of CH4; it plays an important role in adjusting the system reaction temperature, protecting the process catalyst from sintering and preventing resistance from increasing, reducing the risk of equipment failure, and increasing methanol production. In the actual production process, the process gas passes through the conversion furnace of the conversion section and then cools down to about 35-40℃ through various heat exchangers and is sent to the synthesis section. After heat exchange with each heat exchanger, the process gas needs to be collected through the gas-liquid separator. Since this part of the condensate belongs to high-temperature steam condensate, the condensate temperature is too high and does not meet the process requirements for use as air-cooled tower water supplement, and it cannot be fully utilized, resulting in a great waste of energy. To reduce its temperature to a reasonable range, a large amount of desalted water is required for heat exchange, which is very expensive. Utility Model Content

[0003] 1. Technical issues

[0004] The utility model provides a device for recovering condensate from a methanol production process, aiming to overcome the deficiencies of the existing technology, reduce the usage of desalted water, greatly improve the utilization rate of this part of condensate, reduce operating costs, and reduce fixed investment.

[0005] (II) Technical content

[0006] In order to solve the above technical problems, the technical solution of the utility model is: a device for recovering condensate from a methanol production process, comprising a first heat exchanger, a first separator, a second heat exchanger, a second separator, a third heat exchanger, and a third separator which are connected in sequence, the gas inlet of the first heat exchanger is connected to a process gas discharge port, the bottom condensate outlets of the first separator, the second separator and the third separator converge through a pipeline and are connected to a stripping tower, the bottom of the stripping tower is connected to a blower, the air inlet of the blower is connected to a dirty nitrogen discharge port, the top of the stripping tower is provided with a dirty nitrogen release port, the liquid outlet at the bottom of the stripping tower is connected to a condensate pump, and the other end of the condensate pump is connected to a condensate air cooler.

[0007] Furthermore, the bottom condensate outlets of the first separator, the second separator and the third separator are connected to the middle of the stripping tower through pipelines, and the air outlet of the blower is connected to the bottom of the stripping tower.

[0008] Furthermore, the first heat exchanger is a boiler feed water preheater.

[0009] Furthermore, the second heat exchanger is a desalted water preheater.

[0010] Furthermore, the third heat exchanger is a heating water preheater.

[0011] Furthermore, the first separator, the second separator and the third separator are all gas-liquid separators.

[0012] Furthermore, the exhaust port of the third separator is communicated with an external reformed gas air cooler.

[0013] (III) Technical Effect

[0014] Compared with the prior art, the utility model has the following advantages: the device uses a blower to introduce air separation dirty nitrogen gas at the lower part of the stripping tower to reversely exchange heat with the condensate, and then discharges the nitrogen from the vent at the top of the tower. The condensate pump is used to send the liquid in the tower to the condensate air cooler for heat exchange and cooling to about 30-35°C and then sent to various units as water replenishment for the air cooler, thereby improving the utilization rate of the condensate and reducing the amount of demineralized water used. The blower is used to send the air separation dirty nitrogen gas (20-25°C) to the stripping tower for countercurrent heat exchange with the condensate. Since the dirty nitrogen gas is dry and has a low relative humidity, the condensate continuously evaporates and diffuses into the dirty nitrogen gas, taking out most of the heat and reducing the condensate temperature to about 55°C. The condensate is then sent to the air cooler by the condensate pump for cooling (27-32°C) and sent to other processes for use. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The utility model is a system schematic diagram of a device for recovering condensate from a methanol production process.

[0016] As shown in the figure: 1. The first heat exchanger; 2. The first separator; 3. The second heat exchanger; 4. The second separator; 5. The third heat exchanger; 6. The third separator; 7. The stripping tower; 8. The blower; 9. The vent; 10. The condensate pump; 11. The condensate air cooler. DETAILED DESCRIPTION

[0017] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "inside", "outside", "center", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction structure and operation. Therefore, they should not be understood as limitations on the present invention.

[0018] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "provided with", "installed", "connected", "connected" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection, it can be a mechanical connection, it can be an electrical connection, it can be a direct connection, it can be indirectly connected through an intermediate medium, and it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0019] The utility model is further described in detail below in conjunction with the accompanying drawings.

[0020] Combined with Figure 1 A device for recovering condensate from a methanol production process comprises a first heat exchanger 1, a first separator 2, a second heat exchanger 3, a second separator 4, a third heat exchanger 5, and a third separator 6 which are connected in sequence, wherein the gas inlet of the first heat exchanger 1 is connected to a process gas discharge port, the exhaust port of the third separator 6 is connected to an external reforming gas air cooler, the bottom condensate outlets of the first separator 2, the second separator 4, and the third separator 6 converge through a pipeline and are connected to a stripping tower 7, the bottom of the stripping tower 7 is connected to a blower 8, the air inlet of the blower 8 is connected to a dirty nitrogen discharge port, the top of the stripping tower 7 is provided with a dirty nitrogen release port 9, the liquid outlet at the bottom of the stripping tower 7 is connected to a condensate pump 10, and the other end of the condensate pump 10 is connected to a condensate air cooler 11.

[0021] The bottom condensate outlets of the first separator 2 , the second separator 4 and the third separator 6 are connected to the middle of the stripping tower 7 through pipelines, and the air outlet of the blower 8 is connected to the bottom of the stripping tower 7 .

[0022] The first heat exchanger 1 adopts a boiler feed water preheater, model C60604, the second heat exchanger 3 adopts a desalted water preheater, model C60605, and the third heat exchanger 5 adopts a heating water preheater, model C606010.

[0023] The first separator 2, the second separator 4 and the third separator 6 are all gas-liquid separators, and the models are F60602, F60603 and F60607 respectively.

[0024] The working principle of the utility model is described as follows:

[0025] Reference Figure 1The process flow of producing the process condensate of the utility model is as follows: the process gas at about 320°C is passed through the C60604 boiler feed water preheater and the deoxygenated water of the deaerator for heat exchange, and the process gas temperature is reduced to 150-180°C. After the process condensate is separated by the first conversion gas separator F60602, it is passed through the C60605 desalted water preheater and the desalted water output by the desalted water station for heat exchange, and the process gas temperature will be less than 110°C. After the process condensate is separated by the second conversion gas separator F60603, it is passed through the C606010 heating water preheater and the heating water of the heating water network for heat exchange, and the process condensate is separated by the third conversion gas separator F60607, and the temperature will be less than 85°C; finally, the process gas is cooled to 30-45°C by the conversion gas air cooler and sent to the synthesis section.

[0026] Reference Figure 1 The process flow of cooling the process condensate of the utility model is as follows: after the process condensate at the outlets of the first conversion gas separator F60602, the second conversion gas separator F60603, and the third converter separator F60607 enter the stripping tower (model E60601), a blower (model J60602) is used to extract the dirty nitrogen gas generated by air separation and enter the stripping tower from the bottom. The dirty nitrogen gas and the process condensate entering from the middle of the stripping tower are reversely heat exchanged to reduce the condensate temperature to <55°C; the process condensate is sent to the condensate air cooler (model C60607) by a condensate pump (model J60601A / B) to cool it to 27-32°C and then sent to users for use.

[0027] The above description of the utility model and its implementation methods is not restrictive. The drawings show only one implementation method of the utility model, and the actual structure is not limited thereto. In short, if ordinary technicians in this field are inspired by it and design structural methods and embodiments similar to the technical solution without creativity without departing from the purpose of the invention of the utility model, they should all fall within the protection scope of the utility model.

Claims

1. A device for recovering condensate from a methanol production process, comprising a first heat exchanger (1), a first separator (2), a second heat exchanger (3), a second separator (4), a third heat exchanger (5), and a third separator (6) which are connected in sequence, wherein the gas inlet of the first heat exchanger (1) is connected to the process gas discharge port, and is characterized in that: The condensate outlets at the bottom of the first separator (2), the second separator (4) and the third separator (6) are converged through a pipeline and connected to a stripping tower (7); a blower (8) is connected to the bottom of the stripping tower (7); an air inlet of the blower (8) is connected to a dirty nitrogen gas discharge port; a dirty nitrogen gas release port (9) is provided at the top of the stripping tower (7); a condensate pump (10) is connected to the liquid outlet at the bottom of the stripping tower (7); and the other end of the condensate pump (10) is connected to a condensate air cooler (11).

2. The device for recovering condensate from a methanol production process according to claim 1, characterized in that: The bottom condensate outlets of the first separator (2), the second separator (4) and the third separator (6) are connected to the middle of the stripping tower (7) through pipelines, and the air outlet of the blower (8) is connected to the bottom of the stripping tower (7).

3. The device for recovering condensate from a methanol production process according to claim 1, characterized in that: The first heat exchanger (1) is a boiler feed water preheater.

4. The device for recovering condensate from a methanol production process according to claim 3, characterized in that: The second heat exchanger (3) is a desalted water preheater.

5. The device for recovering condensate from a methanol production process according to claim 4, characterized in that: The third heat exchanger (5) is a heating water preheater.

6. The device for recovering condensate from a methanol production process according to claim 1, characterized in that: The first separator (2), the second separator (4) and the third separator (6) are all gas-liquid separators.

7. The device for recovering condensate from a methanol production process according to claim 1, characterized in that: The exhaust port of the third separator (6) is in communication with an external reformed gas air cooler.

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