Impurity removal and recovery device and recovery and utilization method for coal water slurry gasification waste slurry

Abstract

The invention relates to the technical field of waste slurry recycling, in particular to an impurity removing and recycling device and recycling method for coal water slurry gasification waste slurry, the impurity removing and recycling device comprises a coal grinding unit and a waste slurry recycling unit, a coal grinding machine of the coal grinding unit is communicated with a drum screen of a screening assembly through a coal grinding machine slurry outlet, and the drum screen is respectively communicated with a coal grinding machine discharging groove and a vibrating screen. The vibrating screen is communicated with a waste slurry collecting tank of the waste slurry recycling unit, the waste slurry collecting tank is communicated with a waste slurry recycling pump, and the waste slurry recycling pump is communicated with a feeding port of the coal mill through a recycling pipeline. According to the impurity removal and recovery device and the recovery and utilization method for the coal water slurry gasification waste slurry, the waste slurry in the waste slurry collecting tank can be conveyed to the feed port of the coal mill again through the waste slurry recovery pump and the recovery pipeline, so that the cyclic utilization of unreacted coal resources is realized, the waste of coal is greatly reduced, and the production cost is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of waste slurry recovery, and in particular to a device for removing impurities from waste slurry from water-coal slurry gasification and a recycling method. Background Art

[0002] The generation of waste slurry during the preparation of coal slurry from water-coal slurry gasification is an inevitable problem in the operation principle of the equipment. These waste slurries usually contain unreacted coal particles, ash and other impurities. On the one hand, waste slurry causes waste of coal, and on the other hand, it causes on-site environmental pollution. The harmful substances in it may penetrate into the soil and water, destroying the ecological balance. The labor intensity of cleaning up waste slurry is high, and how to efficiently remove waste slurry is a common problem faced by all enterprises. Recycling waste slurry is an important link to improve resource utilization and reduce environmental pollution, but the difficulty lies in the fact that the waste slurry itself is defined as waste in the original production process, and the substances contained in it are complex, including impurities such as metal, wood, plastic, and large particles of coal. In the past, simple and extensive recovery methods were difficult to effectively remove impurities in waste slurry. If the waste slurry that was not fully removed was reused in production, the impurities may affect the stability of subsequent processes and product quality. If the waste slurry is not separated and directly used, it is extremely difficult, which is easy to cause pipeline and pump blockage, agitator freezing, flow meter inaccuracy and other problems. Therefore, it is urgent to develop an efficient water-coal slurry gasification waste slurry impurity removal and recovery device. Summary of the invention

[0003] The purpose of the present invention is to provide a device for removing impurities and recovering waste slurry from water-coal slurry gasification and a recycling method, which can transport the waste slurry in the waste slurry collecting tank back to the feed port of the coal mill via a waste slurry recovery pump and a recovery pipeline, thereby realizing the recycling of unreacted coal resources, greatly reducing the waste of coal and reducing production costs.

[0004] To achieve the above-mentioned purpose, the present invention provides a device for removing impurities and recovering waste slurry from water-coal slurry gasification, comprising a coal grinding unit and a waste slurry recovery unit, the coal grinding unit's coal grinding machine is connected to a drum screen of a screening assembly through a coal grinding machine outlet, the drum screen is respectively connected to a coal grinding machine outlet trough and a vibrating screen, the vibrating screen is connected to a waste slurry collecting trough of the waste slurry recovery unit, the waste slurry collecting trough is connected to a waste slurry recovery pump, and the waste slurry recovery pump is connected to a coal grinding machine feed port through a recovery pipeline.

[0005] Preferably, a waste slurry agitator is provided in the waste slurry collecting tank, a sewage valve is provided at the bottom of the waste slurry collecting tank, a waste slurry discharge valve is provided at the middle and lower part of the waste slurry collecting tank, and the waste slurry discharge valve is connected to the waste slurry recovery pump.

[0006] Preferably, the drum screen discharge port of the drum screen is connected to the coal mill discharge trough, and the waste slurry outlet of the drum screen is connected to the vibrating screen.

[0007] Preferably, the vibrating screen is provided with a spray head above the screen, and the vibrating screen outlet of the vibrating screen is connected to the waste pulp collecting tank.

[0008] Preferably, a water adding valve and a remote liquid level meter are provided in the waste slurry collecting tank.

[0009] Preferably, a discharge trough agitator is provided in the coal mill discharge trough.

[0010] Preferably, the inlet and outlet of the waste slurry recovery pump are both provided with flushing water valves, and the recovery pipeline is provided with a waste slurry flow meter.

[0011] The above-mentioned method for recycling the impurity removal and recovery device of water-coal slurry gasification waste slurry comprises the following steps: S1. The coal slurry from the coal mill enters the drum screen, and the drum screen sends the qualified coal slurry after screening into the coal mill discharge trough, and the waste slurry enters the vibrating screen; S2, the waste pulp after screening by the vibrating screen enters the waste pulp collection tank, and the impurities that cannot pass the screen enter the impurity collection pool; S3. The waste slurry obtained by adding water to the waste slurry collection tank and stirring enters the recovery pipeline through the waste slurry recovery pump, and returns to the coal mill for re-slurrying after passing through the waste slurry flowmeter.

[0012] Preferably, in S2, during screening, the spray head adds water to the screen to flush the screen, and impurities cannot pass through the screen.

[0013] Preferably, in S3, a flushing water valve is used to flush the recovery pipeline.

[0014] Therefore, the present invention adopts the above-mentioned impurity removal and recovery device and recycling method of water-coal slurry gasification waste slurry, which can transport the waste slurry in the waste slurry collection tank back to the coal mill feed port via the waste slurry recovery pump and the recovery pipeline, thereby realizing the recycling of unreacted coal resources, greatly reducing coal waste, reducing production costs, improving coal utilization, improving the environmental sanitation level of the work site, and reducing the labor pressure of workers in cleaning waste slurry.

[0015] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of a device for removing impurities and recovering waste slurry from gasification of water-coal slurry according to the present invention.

[0017] Reference numerals: 1. Coal mill; 2. Drum screen; 3. Vibrating screen; 4. Coal mill discharge trough; 5. Waste slurry collection trough; 6. Waste slurry recovery pump; 7. Discharge trough agitator; 8. Waste slurry flowmeter; 9. Recovery pipeline; 10. Drain valve; 11. Waste slurry discharge valve; 12. Waste slurry agitator. DETAILED DESCRIPTION

[0018] The present invention is further described below in conjunction with the accompanying drawings and embodiments. Unless otherwise defined, the technical terms or scientific terms used in the present invention should be the common meanings understood by people with ordinary skills in the field to which the present invention belongs. The above-mentioned features or features mentioned in the specific examples mentioned in the present invention can be combined arbitrarily, and these specific embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention.

[0019] Example 1 like Figure 1 As shown, the present invention provides a device for removing impurities and recovering waste slurry from water-coal slurry gasification, comprising a coal grinding unit and a waste slurry recovery unit. The coal mill 1 of the coal grinding unit is connected to the drum screen 2 of the screening assembly through the slurry outlet of the coal mill 1, and the drum screen 2 is respectively connected to the coal mill discharge trough 4 and the vibrating screen 3. The vibrating screen 3 is connected to the waste slurry collecting trough 5 of the waste slurry recovery unit, and the waste slurry collecting trough 5 is connected to the waste slurry recovery pump 6, and the waste slurry recovery pump 6 is connected to the feed port of the coal mill 1 through the recovery pipeline 9.

[0020] During the process of preparing coal slurry in the coal grinding unit, the waste slurry obtained enters the waste slurry recovery unit, and returns to the coal grinding unit to prepare coal slurry after screening. The coal mill 1 is a wet overflow mill, and the drum screen 2 screens the coal slurry. The qualified coal slurry enters the coal mill discharge trough 4, and the waste slurry enters the vibrating screen 3 to screen out impurities and then enters the waste slurry collection trough 5. The waste slurry in the waste slurry collection trough 5 returns to the coal mill 1 through the waste slurry recovery pump 6 and the recovery pipeline 9.

[0021] A waste slurry agitator 12 is provided in the waste slurry collecting tank 5, and a sewage valve 10 is provided at the bottom of the waste slurry collecting tank 5. A waste slurry discharge valve 11 is provided at the middle and lower part of the waste slurry collecting tank 5, and the waste slurry discharge valve 11 is connected to the waste slurry recovery pump 6. The waste slurry agitator 12 mixes the waste slurry and the added water evenly, so that the waste slurry can be returned to the coal mill 1 through the waste slurry discharge valve 11 and the waste slurry recovery pump 6.

[0022] The discharging port of the drum screen 2 is communicated with the coal mill discharging trough 4 , and the waste slurry outlet of the drum screen 2 is communicated with the vibrating screen 3 .

[0023] The vibrating screen 3 is provided with a spray head above the screen, and the vibrating screen 3 outlet of the vibrating screen 3 is connected with the waste slurry collecting tank 5. The spray head sprays water onto the screen of the vibrating screen 3, so as to facilitate rapid screening of coal and impurities on the screen.

[0024] A water adding valve and a remote level gauge are provided in the waste slurry collection tank 5. Water enters the waste slurry recovery tank through the water adding valve to dilute the coal slurry therein. The remote level gauge is provided to detect the liquid level.

[0025] A discharge trough agitator 7 is provided in the coal mill discharge trough 4 , and the discharge trough agitator 7 stirs the coal slurry to facilitate the coal slurry to move out of the coal mill discharge trough 4 .

[0026] The inlet and outlet of the waste slurry recovery pump 6 are both provided with flushing water valves, and the recovery pipeline 9 is provided with a waste slurry flow meter 8 .

[0027] Example 2 The method for recycling the impurity removal and recovery device of the water-coal slurry gasification waste slurry in Example 1 comprises the following steps: S1. The coal slurry from the coal mill 1 enters the drum screen 2. The drum screen 2 sends the qualified coal slurry after screening to the coal mill discharge trough 4, and the waste slurry enters the vibrating screen 3.

[0028] S2, the waste pulp after screening by the vibrating screen 3 enters the waste pulp collecting tank 5, and the impurities that cannot pass the screening enter the impurity collecting pool; In S2, during screening, the sprinkler head adds water to the screen to flush the screen, and the impurities cannot pass through the screen.

[0029] S3, the waste slurry obtained by adding water to the waste slurry collection tank 5 and stirring enters the recovery pipeline through the waste slurry recovery pump 6, and returns to the coal mill 1 after passing through the waste slurry flowmeter 8 to be re-pulped.

[0030] In S3, the recovery line 9 is flushed using a flushing water valve.

[0031] Taking a single mill producing 60m³ / h coal slurry as an example, the waste slurry rate before the waste slurry recovery device of Example 1 is not used is about 1.5%, the waste slurry volume per hour is 60m³ / h×1.5%=0.9m³, and the coal slurry density is: 1219kg / m 3 , concentration: 61%, coal waste per hour: 0.9m³×1219kg / m 3 ×61%÷1000=0.669 tons, coal waste per day: 0.669 tons×24h=16 tons. After using the device of Example 1, basically no waste pulp is generated, and the economic and environmental benefits are significant.

[0032] Therefore, the present invention adopts the above-mentioned impurity removal and recovery device and recycling method of water-coal slurry gasification waste slurry, which can re-transport the waste slurry in the waste slurry collection tank to the coal mill feed port via the waste slurry recovery pump and the recovery pipeline, thereby realizing the recycling of unreacted coal resources, greatly reducing coal waste, reducing production costs, and improving coal utilization.

[0033] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A device for removing impurities and recovering waste slurry from coal-water slurry gasification, characterized by: It includes a coal grinding unit and a waste slurry recovery unit. The coal grinding unit's coal grinding mill is connected to the drum screen of the screening assembly through the coal grinding mill's slurry outlet. The drum screen is connected to the coal grinding mill's discharge trough and the vibrating screen respectively. The vibrating screen is connected to the waste slurry collecting trough of the waste slurry recovery unit. The waste slurry collecting trough is connected to the waste slurry recovery pump. The waste slurry recovery pump is connected to the coal grinding mill's feed port through a recovery pipeline.

2. The impurity removal and recovery device for coal-water slurry gasification waste slurry according to claim 1, characterized in that: A waste slurry agitator is arranged in the waste slurry collecting tank, a sewage discharge valve is arranged at the bottom of the waste slurry collecting tank, a waste slurry discharge valve is arranged at the middle and lower part of the waste slurry collecting tank, and the waste slurry discharge valve is connected with the waste slurry recovery pump.

3. The impurity removal and recovery device for coal-water slurry gasification waste slurry according to claim 1, characterized in that: The drum screen discharge port of the drum screen is connected with the coal mill discharge trough, and the waste slurry outlet of the drum screen is connected with the vibrating screen.

4. The impurity removal and recovery device for coal-water slurry gasification waste slurry according to claim 1, characterized in that: The vibrating screen is provided with a spray head above the screen mesh, and the vibrating screen outlet of the vibrating screen is connected with the waste pulp collecting tank.

5. The impurity removal and recovery device for coal-water slurry gasification waste slurry according to claim 1, characterized in that: A water adding valve and a remote liquid level meter are provided in the waste slurry collection tank.

6. The impurity removal and recovery device for coal-water slurry gasification waste slurry according to claim 1, characterized in that: A discharge trough agitator is provided in the coal mill discharge trough.

7. The impurity removal and recovery device for coal-water slurry gasification waste slurry according to claim 1, characterized in that: The inlet and outlet of the waste slurry recovery pump are both equipped with flushing water valves, and the recovery pipeline is equipped with a waste slurry flow meter.

8. A method for recycling waste slurry from coal-water slurry gasification according to any one of claims 1 to 7, characterized in that: The following steps are included: S1. The coal slurry from the coal mill enters the drum screen, and the drum screen sends the qualified coal slurry after screening into the coal mill discharge trough, and the waste slurry enters the vibrating screen; S2, the waste pulp after screening by the vibrating screen enters the waste pulp collection tank, and the impurities that cannot pass the screen enter the impurity collection pool; S3. The waste slurry obtained by adding water to the waste slurry collection tank and stirring enters the recovery pipeline through the waste slurry recovery pump, and returns to the coal mill for re-slurrying after passing through the waste slurry flowmeter.

9. The recycling method of the impurity removal and recovery device of water-coal slurry gasification waste slurry according to claim 8, characterized in that: In S2, during screening, the sprinkler head adds water to the screen to flush the screen, and the impurities cannot pass through the screen.

10. The recycling method of the impurity removal and recovery device of water-coal slurry gasification waste slurry according to claim 8, characterized in that: In S3, the recovery line is flushed using a flushing water valve.

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