System for treating and recycling gas water

Abstract

The utility model discloses a gas water treatment and recycling system which is characterized by comprising a gasification furnace, a venturi scrubber, a washing separator, a first heat exchanger, a second heat exchanger, an expander, a tar separator, an oil separator and a centrifugal desliming machine, a cold medium channel of the second heat exchanger is divided into three relatively independent channels, a relatively large temperature difference is always kept between gas water and circulating water in the process that the gas water passes through the second heat exchanger, the heat exchange efficiency of the gas water and the circulating water is further improved, meanwhile, the temperature of circulating return water can be monitored through a temperature sensor, and the energy consumption is reduced. When the monitored temperature of the circulating return water exceeds a preset value, the flow regulating valve needs to be opened to increase the flow of the circulating water, so that the temperature of the circulating return water is ensured to meet the process requirement, and the risk of water attack is avoided.

Description

Technical field:

[0001] The utility model relates to a gas water processing system, in particular to a gas water processing and recycling system. Background technology:

[0002] When producing urea, the raw coal needs to be gasified using steam and oxygen as gasifying agents, and a coal gasification reaction occurs in the gasifier to obtain raw coal gas. Since there is a lot of dust and impurities in the raw coal gas, the raw coal gas is usually sent to a water washing tower to wash the impurities in the raw synthesis gas by spraying water. The washing water after washing is called coal gas water. Because the temperature of coal gas water is relatively high, which can be as high as 190°C, the coal gas water is usually removed from impurities and cooled before reuse. However, in the actual operation process, after the system has been running for a long period of time, the heat exchange effect of the cooling equipment decreases, resulting in a circulating water return temperature of up to about 100°C. When the operating conditions fluctuate or the circulating water pressure difference is small, the circulating water return temperature exceeds 120°C and it is very easy to cause water hammer in the circulating water pipeline. In severe cases, there is a risk of damage to the circulating water pipeline and resulting in shutdown. Utility model content:

[0003] In order to solve the above problems, the purpose of the utility model is to provide a gas water treatment and recycling system.

[0004] The utility model is implemented by the following technical solutions:

[0005] A gas water treatment and recycling system comprises a gasifier, a venturi scrubber, a scrubber separator, a first heat exchanger, a second heat exchanger, an expander, a tar separator, an oil separator and a centrifugal desludging machine;

[0006] The raw coal gas outlet at the top of the gasifier is connected to the air inlet of the venturi scrubber through a pipeline, the outlet at the bottom of the venturi scrubber is connected to the inlet of the scrubber separator through a pipeline, the liquid outlet of the scrubber separator is connected to the heat medium inlet of the first heat exchanger through a pipeline, the heat medium outlet of the first heat exchanger is connected to the heat medium inlet of the second heat exchanger through a pipeline, the heat medium outlet of the second heat exchanger is connected to the inlet of the expander through a pipeline, the water outlet of the expander and the outlet of the flocculant storage tank are both connected to the inlet of the tar separator through pipelines, the middle outlet of the tar separator is connected to the inlet of the oil separator through a pipeline, the middle outlet of the oil separator is connected to the inlet of the buffer tank through a pipeline, the outlet of the buffer tank is connected to the cold medium inlet of the first heat exchanger through a pipeline, and the cold medium outlet of the first heat exchanger is connected to the water inlet of the venturi scrubber through a pipeline;

[0007] The water outlet of the circulating water pipeline is communicated with the cold medium inlet of the second heat exchanger, and the cold medium outlet of the second heat exchanger is communicated with the water inlet of the circulating water return pipeline.

[0008] Furthermore, the bottom outlet of the tar separator is connected to the inlet of the centrifugal desludging machine, and the liquid outlet of the centrifugal desludging machine and the bottom outlet of the oil separator are both connected to the inlet of the tar separator through pipelines.

[0009] Furthermore, it also includes a waste heat boiler, the air outlet of the washing separator is connected to the air inlet of the waste heat boiler through a pipeline, and the condensate outlet of the waste heat boiler is connected to the heat medium inlet of the first heat exchanger through a pipeline.

[0010] Furthermore, the cold medium channel of the second heat exchanger is divided into three relatively independent channels, and the water outlet end of the circulating water pipeline is divided into three paths, which are respectively connected to the inlets of the three cold medium channels of the second heat exchanger, and the outlets of the three cold medium channels of the second heat exchanger are all connected to the water inlet end of the circulating return water pipeline.

[0011] Furthermore, a temperature sensor is provided at the water inlet end of the circulating water return pipeline, and a flow regulating valve is provided at the water outlet end of the circulating water supply pipeline.

[0012] Advantages of the utility model:

[0013] The utility model divides the cold medium channel of the second heat exchanger into three relatively independent channels, so as to keep a relatively large temperature difference between the gas water and the circulating water during the process of passing through the second heat exchanger, thereby improving the heat exchange efficiency between the gas water and the circulating water. At the same time, the temperature of the circulating return water can be monitored by a temperature sensor. When the monitored circulating return water temperature exceeds a preset value, the flow regulating valve needs to be opened to increase the flow of the circulating water, thereby ensuring that the circulating return water temperature meets the process requirements and avoiding the risk of water hammer. Description of the drawings:

[0014] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0015] Figure 1 Schematic diagram of system connection of this embodiment.

[0016] In the figure: gasifier 1, venturi scrubber 2, scrubber separator 3, first heat exchanger 4, second heat exchanger 5, expander 6, tar separator 7, oil separator 8, centrifugal desludging machine 9, buffer tank 10, flocculant storage tank 11, waste heat boiler 12, flow regulating valve 13, temperature sensor 14. Specific implementation method:

[0017] The following will be combined with the drawings in 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 in 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.

[0018] Embodiment 1:

[0019] like Figure 1 A gas water treatment and recycling system shown includes a gasifier 1, a venturi scrubber 2, a scrubber separator 3, a first heat exchanger 4, a second heat exchanger 5, an expander 6, a tar separator 7, an oil separator 8 and a centrifugal desludging machine 9;

[0020] The syngas outlet at the top of the gasifier 1 is connected to the air inlet of the venturi scrubber 2 through a pipeline, the outlet at the bottom of the venturi scrubber 2 is connected to the inlet of the scrubber separator 3 through a pipeline, the liquid outlet of the scrubber separator 3 is connected to the heat medium inlet of the first heat exchanger 4 through a pipeline, the heat medium outlet of the first heat exchanger 4 is connected to the heat medium inlet of the second heat exchanger 5 through a pipeline, the heat medium outlet of the second heat exchanger 5 is connected to the inlet of the expander 6 through a pipeline, and the water outlet of the expander 6 and the outlet of the flocculant storage tank 11 are both connected to the tar separator 7 through pipelines. The inlet of the tar separator 7 is connected, the middle outlet of the tar separator 7 is connected with the inlet of the oil separator 8 through a pipeline, the middle outlet of the oil separator 8 is connected with the inlet of the buffer tank 10 through a pipeline, the outlet of the buffer tank 10 is connected with the cold medium inlet of the first heat exchanger 4 through a pipeline, and the cold medium outlet of the first heat exchanger 4 is connected with the water inlet of the venturi scrubber 2 through a pipeline; the bottom outlet of the tar separator 7 is connected with the inlet of the centrifugal desludging machine 9, and the liquid outlet of the centrifugal desludging machine 9 and the bottom outlet of the oil separator 8 are both connected with the inlet of the tar separator 7 through pipelines.

[0021] The cold medium channel of the second heat exchanger 5 is divided into three relatively independent channels, and the water outlet of the circulating water pipeline is divided into three paths, which are respectively connected to the inlets of the three cold medium channels of the second heat exchanger 5, and the outlets of the three cold medium channels of the second heat exchanger 5 are all connected to the water inlet of the circulating return water pipeline. A temperature sensor 14 is provided at the water inlet of the circulating return water pipeline, and a flow regulating valve 13 is provided at the water outlet of the circulating water pipeline.

[0022] This embodiment also includes a waste heat boiler 12, the air outlet of the washing separator 3 is connected to the air inlet of the waste heat boiler 12 through a pipeline, and the condensate outlet of the waste heat boiler 12 is connected to the heat medium inlet of the first heat exchanger 4 through a pipeline.

[0023] Job Description:

[0024] The raw coal gas generated in the gasifier 1 enters the venturi scrubber 2 and is washed with water, and then passes through the washing separator 3 to achieve gas-liquid separation. The separated coal gas water passes through the first heat exchanger 4 and the second heat exchanger 5 in turn to cool down through heat exchange. The cooled coal gas water passes through the expander 6 to expand its volume, achieving the effect of cooling and reducing pressure. Then the coal gas water enters the tar separator 7, and by adding flocculants, flocculation and sedimentation occur, so that the sediment with higher density at the bottom of the tar separator 7 enters the centrifugal desludging machine 9 for mud and water separation, and the separated water returns to the tar separator. 7 to participate in flocculation, sedimentation and separation again; the oil and water that have settled in the tar separator 7 enter the oil separator 8, and due to the different densities, stratification will occur; the oil with a larger specific gravity is discharged from the bottom of the oil separator 8 and returns to the tar separator 7 to participate in flocculation, sedimentation and separation again, the oil with a smaller specific gravity is discharged from the upper part of the oil separator 8, and the water is discharged from the middle part of the oil separator 8 into the buffer tank 10 for temporary storage, and then enters the first heat exchanger 4 as a cold medium to exchange heat with the gas water, and after heat exchange, it is reused as washing water of the Venturi scrubber 2.

[0025] The raw coal gas separated by the washing separator 3 enters the waste heat boiler 12 as a heat source, and uses the heat it carries to produce steam. Since the washed synthesis gas also carries moisture, condensed water will be produced after doing work in the waste heat boiler 12. This part of condensed water enters the first heat exchanger 4 together with the coal gas water for heat exchange and cooling.

[0026] In order to ensure the cooling effect of the gas water, the first heat exchanger 4 and the second heat exchanger 5 are provided in this embodiment. After the gas water is initially cooled by heat exchange in the first heat exchanger 4, it enters the second heat exchanger 5 to exchange heat with the circulating water at 28°C. In order to ensure that the temperature of the circulating return water is within the range required by the process, so as to avoid the water hammer accident in the circulating return water pipeline caused by the circulating return water temperature being too high, the cold medium channel of the second heat exchanger 5 is divided into three relatively independent channels in this embodiment, so as to keep a relatively large temperature difference between the gas water and the circulating water during the process of passing through the second heat exchanger 5, thereby improving the heat exchange efficiency between the gas water and the circulating water. At the same time, the temperature of the circulating return water can be monitored by the temperature sensor 14. When the monitored circulating return water temperature exceeds the preset value, the flow regulating valve 13 needs to be opened to increase the flow of the circulating water, thereby ensuring that the circulating return water temperature meets the process requirements and avoiding the risk of water hammer.

[0027] The above description is only a preferred embodiment of the present invention and is 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 gas water treatment and recycling system, characterized in that: It includes a gasifier, a venturi scrubber, a scrubber separator, a first heat exchanger, a second heat exchanger, an expander, a tar separator, an oil separator and a centrifugal desludging machine; The raw coal gas outlet at the top of the gasifier is connected to the air inlet of the venturi scrubber through a pipeline, the outlet at the bottom of the venturi scrubber is connected to the inlet of the scrubber separator through a pipeline, the liquid outlet of the scrubber separator is connected to the heat medium inlet of the first heat exchanger through a pipeline, the heat medium outlet of the first heat exchanger is connected to the heat medium inlet of the second heat exchanger through a pipeline, the heat medium outlet of the second heat exchanger is connected to the inlet of the expander through a pipeline, the water outlet of the expander and the outlet of the flocculant storage tank are both connected to the inlet of the tar separator through pipelines, the middle outlet of the tar separator is connected to the inlet of the oil separator through a pipeline, the middle outlet of the oil separator is connected to the inlet of the buffer tank through a pipeline, the outlet of the buffer tank is connected to the cold medium inlet of the first heat exchanger through a pipeline, and the cold medium outlet of the first heat exchanger is connected to the water inlet of the venturi scrubber through a pipeline; The water outlet of the circulating water pipeline is communicated with the cold medium inlet of the second heat exchanger, and the cold medium outlet of the second heat exchanger is communicated with the water inlet of the circulating water return pipeline.

2. A gas water treatment and recycling system according to claim 1, characterized in that: The bottom outlet of the tar separator is communicated with the inlet of the centrifugal desludging machine, and the liquid outlet of the centrifugal desludging machine and the bottom outlet of the oil separator are both communicated with the inlet of the tar separator through pipelines.

3. A gas water treatment and recycling system according to claim 1, characterized in that: It also includes a waste heat boiler, the air outlet of the washing separator is connected to the air inlet of the waste heat boiler through a pipeline, and the condensate outlet of the waste heat boiler is connected to the heat medium inlet of the first heat exchanger through a pipeline.

4. A gas water treatment and recycling system according to claim 1, characterized in that: The cold medium channel of the second heat exchanger is divided into three relatively independent channels, and the water outlet end of the circulating water pipeline is divided into three paths, which are respectively connected to the inlets of the three cold medium channels of the second heat exchanger, and the outlets of the three cold medium channels of the second heat exchanger are all connected to the water inlet end of the circulating return water pipeline.

5. A gas water treatment and recycling system according to claim 4, characterized in that: A temperature sensor is provided at the water inlet end of the circulating water return pipeline, and a flow regulating valve is provided at the water outlet end of the circulating water supply pipeline.

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