Flushing system applied to wet overflow type rod mill drum screen

Abstract

The utility model belongs to the technical field of coal water slurry gasification, and particularly discloses a washing system applied to a wet overflow rod mill drum screen, which comprises a rod mill, the inlet end of the rod mill is communicated with a slurrying water conveying mechanism used for conveying grinding water, an additive supply mechanism and a raw material supply mechanism capable of quantitatively adding raw coal, a first flow meter is arranged in the middle of the rod mill, and a continuous flushing mechanism for continuously flushing a drum screen of the rod mill is communicated between the discharge end of the first flow meter and the outlet end of the rod mill. The pulping water conveying mechanism, the continuous flushing mechanism and the rod mill are matched, and a pipeline is led out from the back of the first flow meter of pulping water entering the rod mill; the second flow meter and the second control valve are additionally arranged, the second control valve can be used for controlling washing water entering the roller screen of the rod mill to continuously wash the second flow meter according to the blockage condition of the roller screen, so that the smoothness of a screen mesh of the roller screen is ensured, manual adjustment and manual valve opening are not needed, and the washing effect is improved.

Description

Technical Field

[0001] This utility model relates to the field of coal-water slurry gasification technology, specifically to a washing system for a wet overflow rod mill drum screen. Background Technology

[0002] The main process flow of the wet overflow rod mill used in coal-water slurry gasification is that slurry water, raw coal and additives are fed into the rod mill for grinding. After the coal slurry is initially separated by the drum screen at the outlet of the rod mill, it is made into qualified coal slurry of a certain concentration. The quality control of the coal slurry is mainly achieved based on the ratio of slurry water flow rate to raw coal mass.

[0003] During the operation of a wet overflow rod mill drum screen, the material rotates inside the screen cylinder and is subjected to centrifugal force and inertial force, which separates it into particles of different sizes. The fine particles are discharged through the screen holes, while the larger particles are further ground by the drum. During long-term operation, the screen holes often become clogged, causing a decrease in the screening efficiency of the drum screen. In severe cases, coal slurry may even overflow from the drum screen. Conventional rod mill manufacturers will install multiple nozzles above the drum screen inside the drum screen protective cover. The top of the drum protective cover is equipped with a water inlet pipe, which is connected to the nozzles, so that users can connect an external water source to flush the screen when the screen holes are clogged.

[0004] Rotary drum screen flushing is generally controlled manually using manual valves or pneumatic valves controlled by DCS. There is also a method of adding a timer to the pneumatic valve to set a fixed flushing time for automatic flushing. However, all of these methods require the flushing water source to be connected from the external slurry system of the rod mill. The flushing water flow is uncontrollable, which will affect the quality of the coal slurry exiting the rotary drum screen. Therefore, we need to propose a method for flushing the rotary drum of a wet overflow rod mill to solve the above-mentioned problems. Utility Model Content

[0005] The purpose of this invention is to provide a washing system for a wet overflow rod mill drum screen, which improves the automation level of coal slurry preparation, enhances the washing effect of the drum screen, and makes the quality of the prepared coal slurry more stable, thereby solving the problems mentioned in the background art.

[0006] To achieve the above objectives, this utility model provides the following technical solution: a washing system for a wet overflow rod mill drum screen, comprising a rod mill, wherein the inlet end of the rod mill is connected to a pulping water transmission mechanism for transmitting grinding water, an additive supply mechanism, and a raw material supply mechanism for quantitatively adding raw coal, and the outlet end of the rod mill is connected to a discharge mechanism, wherein a first control valve and a first flow meter are sequentially connected on the pipe connecting the pulping water transmission mechanism and the rod mill, the first flow meter is located between the first control valve and the rod mill, and a continuous washing mechanism for continuously washing the drum screen of the rod mill is connected between the discharge end of the first flow meter and the outlet end of the rod mill;

[0007] The continuous flushing mechanism includes a second control valve and a second flow meter. The second flow meter is located between the second control valve and the first flow meter. The other end of the second control valve is connected to the outlet end of the rod mill.

[0008] Preferably, the outlet end of the rod mill is also connected to a water supply mechanism for supplying fresh water. The water supply mechanism includes a water supply pipe connected to the outlet end of the rod mill, and a water supply valve is installed on the water supply pipe.

[0009] Preferably, the pulping water transmission mechanism includes a grinding water tank and a grinding water pump connected to the grinding water tank. The outlet of the grinding water pump is connected to the inlet of the first control valve. The inlet of the grinding water tank is connected to a low-pressure water pump for pulp transmission and a transmission pipeline for transmitting wastewater from other processes.

[0010] Preferably, the raw material supply mechanism includes a silo for storing raw coal, and a raw material weighing feeder is installed below the silo, with the outlet end of the raw material weighing feeder connected to the inlet of the rod mill.

[0011] Preferably, the additive supply mechanism includes an additive tank for storing additives, a second stirrer installed in the additive tank, an additive preparation mechanism for adding additives connected to the inlet of the additive tank, and an outlet end of the additive tank connected to the inlet of a rod mill via a second feed pump.

[0012] Preferably, the additive preparation mechanism includes a preparation tank, a first stirrer is installed inside the preparation tank, the outlet end of the preparation tank is connected to the inside of the additive tank through a first feed pump, and the inlet end of the preparation tank is connected to an additive feed pipe and a fresh water transmission pipe.

[0013] Preferably, the discharge mechanism includes a mill discharge trough, a third agitator is installed inside the mill discharge trough, the inlet of the mill discharge trough is connected to the outlet end of the rod mill, the outlet end of the mill discharge trough is connected to a discharge slurry tank through a low-pressure slurry pump, and the pipeline connecting the discharge slurry tank and the low-pressure slurry pump is connected to the inlet end of the mill discharge trough through a water pipe.

[0014] Compared with the prior art, the beneficial effects of this utility model are:

[0015] 1. This utility model, through the cooperation of a pulping water transmission mechanism, a continuous rinsing mechanism, and a rod mill, leads a pipeline from the first flow meter of pulping water entering the rod mill, and adds a second flow meter and a second control valve. The second control valve can be used to control the second flow meter of the rinsing water entering the rod mill drum screen for continuous rinsing according to the blockage of the drum screen, thereby ensuring the smooth flow of the drum screen mesh. It eliminates the need for manual adjustment and valve opening, thus improving the rinsing effect.

[0016] 2. Because the washing water for the drum screen comes from after the first flow meter of the total pulping water, the ratio of pulping water to raw coal entering the rod mill does not change, so it will not affect the quality of the coal slurry, making the coal slurry preparation more stable. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of this utility model;

[0018] Figure 2 A schematic diagram of the continuous rinsing mechanism of this utility model.

[0019] In the diagram: 1. Rod mill; 2. Continuous flushing mechanism; 21. Second flow meter; 22. Second control valve; 3. Mill discharge chute; 4. Grinding water tank; 41. Grinding water pump; 5. Feeding mechanism; 51. Raw material weighing feeder; 52. Silo; 53. Discharge pump; 6. Mixing tank; 61. First agitator; 62. First feed pump; 7. Additive tank; 8. Second feed pump; 9. First control valve; 10. Low-pressure slurry pump; 11. First flow meter; 12. Water supply valve. Detailed Implementation

[0020] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0021] Please see Figure 1-2 This utility model provides a technical solution: a washing system for a wet overflow rod mill drum screen, including a rod mill 1. The inlet end of the rod mill 1 is connected to a pulping water transmission mechanism for transmitting grinding water, an additive supply mechanism, and a raw material supply mechanism for quantitatively adding raw coal. The outlet end of the rod mill 1 is connected to a discharge mechanism. A first control valve 9 and a first flow meter 11 are sequentially connected on the pipe connecting the pulping water transmission mechanism and the rod mill 1. The first flow meter 11 is located between the first control valve 9 and the rod mill 1, and a continuous washing mechanism 2 for continuously washing the drum screen of the rod mill 1 is connected between the discharge end of the first flow meter 11 and the outlet end of the rod mill 1.

[0022] The continuous flushing mechanism 2 includes a second control valve 22 and a second flow meter 21. The second flow meter 21 is located between the second control valve 22 and the first flow meter 11. The other end of the second control valve 22 is connected to the outlet end of the rod mill 1. By leading a pipeline after the first flow meter 11, the second flow meter 21 and the second control valve 22 are added. The second control valve 22 can be used to control the flushing water entering the rod mill 1 through the second flow meter 21 for continuous flushing according to the blockage of the drum screen. This ensures that the drum screen screen is unobstructed and does not require manual adjustment or valve opening, thus improving the flushing effect. Since the drum screen flushing water comes from after the first flow meter 11 of the total slurry water, the ratio of slurry water to raw coal entering the rod mill 1 does not change, so it will not affect the quality of the coal slurry, making the coal slurry preparation more stable.

[0023] The outlet end of the rod mill 1 is also connected to a water supply mechanism for supplying fresh water. The water supply mechanism includes a water supply pipe connected to the outlet end of the rod mill 1. A water supply valve 12 is installed on the water supply pipe. The end of the water supply pipe away from the rod mill 1 is connected to a fresh water source. When it is necessary to supply fresh water to the inside of the rod mill 1, the water supply valve 12 is opened, and the fresh water is transported to the inside of the rod mill 1 through the water supply pipe.

[0024] The pulping water transmission mechanism includes a grinding water tank 4 and a grinding water pump 41 connected to the grinding water tank 4. The outlet of the grinding water pump 41 is connected to the inlet of the first control valve 9. The inlet of the grinding water tank 4 is connected to a low-pressure water pump for pulping and a transmission pipeline for transmitting wastewater from other sections. The pulp water from the discharge slurry tank is transmitted to the grinding water tank 4 by the low-pressure water pump. At the same time, industrial wastewater and fresh water from other sections are transmitted to the grinding water tank 4 for pulping. The pulping water is then transmitted to the rod mill 1 by controlling the first control valve 9 and the grinding water pump 41. The first flow meter 11 is used to monitor the flow rate of the pulping water entering the rod mill 1 in real time.

[0025] The raw material supply mechanism includes a silo 52 for storing raw coal. A raw material weighing feeder 51 is installed below the silo 52. The outlet end of the raw material weighing feeder 51 is connected to the inlet of the rod mill 1. The raw coal is weighed by the raw material weighing feeder 51 and then transferred to the inside of the rod mill 1 so that the pulping water and raw coal can be added to the rod mill 1 in proportion.

[0026] The additive supply mechanism includes an additive tank 7 for storing additives, a second stirrer installed in the additive tank 7, an additive preparation mechanism for adding additives connected to the inlet of the additive tank 7, and an outlet of the additive tank 7 connected to the inlet of the rod mill 1 via a second feed pump 8. The additives are added to the additive tank 7, and the second stirrer is used to stir the additives in the additive tank 7 to prevent the additives from settling. Then, the second feed pump 8 transfers the additives in the additive tank 7 to the rod mill 1 to ensure the supply of additives in the rod mill 1.

[0027] The additive preparation mechanism includes a preparation tank 6, inside which a first stirrer 61 is installed. The outlet end of the preparation tank 6 is connected to the interior of the additive tank 7 via a first feed pump 62. The inlet end of the preparation tank 6 is connected to an additive feed pipe and a fresh water transmission pipe. By adding additive raw materials and fresh water into the preparation tank 6, the first stirrer 61 is used to stir and mix the raw materials in the preparation tank 6, so that the raw materials can fully and uniformly undergo a dissolution reaction, thereby obtaining the additive. Then, the first feed pump 62 is used to transfer the additive in the preparation tank 6 to the additive tank 7 for storage.

[0028] The discharge mechanism includes a mill discharge trough 3, inside which a third agitator is installed. The inlet of the mill discharge trough 3 is connected to the outlet end of the rod mill 1. The outlet end of the mill discharge trough 3 is connected to a discharge slurry tank via a low-pressure slurry pump 10. The pipe connecting the discharge slurry tank and the low-pressure slurry pump 10 is connected to the inlet end of the mill discharge trough 3 via a water pipe. The slurry flowing out of the outlet of the rod mill 1 enters the mill discharge trough 3. The third agitator is used to stir the slurry in the mill discharge trough 3 to prevent slurry sedimentation. Then, the low-pressure slurry pump 10 is used to transfer the slurry in the mill discharge trough 3 to the discharge slurry tank for processing, thereby facilitating the discharge and processing of the slurry in the rod mill 1.

[0029] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A flushing system for a wet overflow rod mill drum screen, characterized in that: The device includes a rod mill (1), the inlet end of which is connected to a pulping water transmission mechanism for transmitting grinding water, an additive supply mechanism and a raw material supply mechanism for quantitatively adding raw coal, the outlet end of which is connected to a discharge mechanism, and a first control valve (9) and a first flow meter (11) are sequentially connected on the pipe connecting the pulping water transmission mechanism and the rod mill (1). The first flow meter (11) is located between the first control valve (9) and the rod mill (1), and a continuous flushing mechanism (2) for continuously flushing the drum screen of the rod mill (1) is connected between the discharge end of the first flow meter (11) and the outlet end of the rod mill (1). The continuous flushing mechanism (2) includes a second control valve (22) and a second flow meter (21). The second flow meter (21) is located between the second control valve (22) and the first flow meter (11). The other end of the second control valve (22) is connected to the outlet end of the rod mill (1).

2. The flushing system for a wet overflow rod mill drum screen according to claim 1, characterized in that: The outlet end of the rod mill (1) is also connected to a water supply mechanism for supplying fresh water. The water supply mechanism includes a water supply pipe connected to the outlet end of the rod mill (1), and a water supply valve (12) is installed on the water supply pipe.

3. The flushing system for a wet overflow rod mill drum screen according to claim 1, characterized in that: The pulping water transmission mechanism includes a grinding water tank (4) and a grinding water pump (41) connected to the grinding water tank (4). The outlet of the grinding water pump (41) is connected to the inlet of the first control valve (9). The inlet of the grinding water tank (4) is connected to a low-pressure water pump for pulp transmission and a transmission pipeline for transmitting wastewater from other processes.

4. The flushing system for a wet overflow rod mill drum screen according to claim 1, characterized in that: The raw material supply mechanism includes a silo (52) for storing raw coal, and a raw material weighing feeder (51) is installed below the silo (52). The outlet end of the raw material weighing feeder (51) is connected to the inlet of the rod mill (1).

5. The flushing system for a wet overflow rod mill drum screen according to claim 1, characterized in that: The additive supply mechanism includes an additive tank (7) for storing additives, a second stirrer installed in the additive tank (7), an additive preparation mechanism for adding additives connected to the inlet of the additive tank (7), and the outlet of the additive tank (7) connected to the inlet of the rod mill (1) via a second feed pump (8).

6. A washing system for a wet overflow rod mill drum screen according to claim 5, characterized in that: The additive preparation mechanism includes a preparation tank (6), a first stirrer (61) is installed inside the preparation tank (6), the outlet end of the preparation tank (6) is connected to the inside of the additive tank (7) through a first feed pump (62), and the inlet end of the preparation tank (6) is connected to an additive feed pipe and a fresh water transmission pipe.

7. A washing system for a wet overflow rod mill drum screen according to claim 1, characterized in that: The discharge mechanism includes a mill discharge trough (3), a third agitator is installed inside the mill discharge trough (3), the inlet of the mill discharge trough (3) is connected to the outlet end of the rod mill (1), the outlet end of the mill discharge trough (3) is connected to a discharge slurry tank through a low-pressure slurry pump (10), and the pipe connecting the discharge slurry tank and the low-pressure slurry pump (10) is connected to the inlet end of the mill discharge trough (3) through a water pipe.

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