A horizontal screw centrifuge pressure load test system and test method

Abstract

The present invention discloses a pressure load test system for a horizontal screw centrifuge, including a feed system, the feed system including a feed pump, a feed pipeline, and a flow meter for feeding the test material into the centrifuge and calculating the feed amount, the feed pipeline of the test centrifuge is connected to the feed system, the solid phase slag discharge port and the liquid phase clear liquid port of the centrifuge are respectively connected to the discharge system and the collection device, the discharge system includes a belt conveyor, a mud discharge knife gate valve, and the cache system includes a storage tank and an agitator. The electronic control system monitors and controls the feed system, the horizontal screw centrifuge, the discharge system and the cache system. The system obtains the maximum solid load of the centrifuge according to the total solid amount limit of the solid phase waste slag port that is attempted to be discharged, which can be used as a design indicator to accurately deduce the limit of the processing capacity of the horizontal screw centrifuge for different mixed liquids and as a selection guide. This method is only limited to municipal sewage treatment and has good development prospects for development in other fields and industries.

Description

Technical Field

[0001] The present invention relates to the field of horizontal scroll centrifuges, and particularly to a pressure load test system and test method for a horizontal scroll centrifuge. Background Art

[0002] A horizontal scroll centrifuge is a sedimentation device with horizontal spiral discharge and continuous operation. The drum and the screw rotate at high speed in the same direction with a certain differential speed. The material is continuously introduced into the inner cylinder of the feeding screw through the feeding pipe, and after acceleration, it enters the drum. Under the action of the centrifugal force field, the heavier solid phase deposits on the drum wall to form a sediment layer. The feeding screw continuously pushes the deposited solid phase to the conical end of the drum and discharges it outside the machine through the slag discharge port. The lighter liquid phase forms an inner liquid ring and continuously overflows from the large end overflow port of the drum and is discharged outside the machine through the liquid discharge port.

[0003] For the same type of horizontal scroll centrifuge, the treatment load capacity for different sewage is different. The discrimination method provided by the existing test system for the centrifuge test platform with the publication number CN103940672B is to judge the maximum load capacity of a type of horizontal scroll centrifuge by the volume of the solid phase discharged. However, for other mixed liquids with large density deviations, although the volume of the discharged solid waste residue can meet the requirements of this type of horizontal scroll centrifuge, due to the large density, the mass is also large, which will cause errors when selecting the type of horizontal scroll centrifuge for other mixed liquids. Therefore, there is an urgent need for a pressure load test system and method for a horizontal scroll centrifuge to provide experimental verification and theoretical support for the selection applicable to different sewage. Summary of the Invention

[0004] The purpose of the present invention is to solve the deficiencies in the prior art and propose a pressure load test system and test method for a horizontal scroll centrifuge.

[0005] To achieve the above purpose, the present invention adopts the following technical scheme: A pressure load test system for a horizontal scroll centrifuge, including a feeding system;

[0006] The feeding system includes a feeding pump, a feeding pipeline, and a flow meter, which are used to send the test material into the centrifuge and calculate the feeding amount;

[0007] The test horizontal scroll centrifuge is connected to the feeding system;

[0008] The solid phase slag discharge port and the liquid phase clear liquid port are arranged outside the horizontal scroll centrifuge;

[0009] The discharging system includes a belt conveyor, a sludge outlet knife gate valve, and a weight sensor arranged below the knife gate valve, which are used to weigh the discharged test material and recycle it;

[0010] The buffer system includes a storage tank and a stirrer arranged inside the storage tank;

[0011] The electric control system includes a control cabinet, a temperature sensor, a vibration sensor, a speed sensor, a weight sensor, a limit switch, a frequency converter, a relay, an AC contactor, a panel operation switch, a status indicator light, and a display instrument, and is used to monitor and control the feeding system, the horizontal screw centrifuge, the discharging system, and the buffer system.

[0012] As a further description of the above technical solution: It further includes a cleaning system, which internally includes a cleaning centrifugal pump, a cleaning pipeline, a cleaning water pipeline, a solenoid valve, and a check valve, and can clean the entire system after the test.

[0013] As a further description of the above technical solution: The liquid-phase clear liquid outlet is connected to the storage tank through a pipeline, and at the same time, the belt conveyor is also connected to the storage tank.

[0014] As a further description of the above technical solution: All the interfaces connected to the horizontal screw centrifuge in the entire system are quick interfaces.

[0015] As a further description of the above technical solution: A collection device is arranged below the liquid-phase clear liquid outlet, and the collection device is connected to the storage tank through a pipeline.

[0016] As a further description of the above technical solution: The feeding pump is a positive displacement single-screw pump and adopts variable-frequency stepless speed regulation.

[0017] As a further description of the above technical solution: The electric control system is controlled by a PLC system and is provided with manual, semi-automatic, and automatic control modes.

[0018] As a further description of the above technical solution: A drive system is externally connected to the horizontal screw centrifuge, and the drive system internally includes a drum drive system and a screw drive system.

[0019] As a further description of the above technical solution: The drum drive system internally includes a motor and a belt drive system, and the screw drive system includes a hydraulic pump station and a hydraulic system.

[0020] A test method for a pressure load test system of a horizontal screw centrifuge includes the following steps:

[0021] S1. Mix the test material with water to obtain the solid content of the mixed liquid and put it into the storage tank;

[0022] S2. Install the horizontal screw centrifuge to be tested into the above system;

[0023] S3. The feed pump in the feeding system pumps the mixed liquid into the horizontal screw centrifuge along the feed pipeline, and the flowmeter in the feeding system can measure the feed rate.

[0024] S4. The horizontal screw centrifuge separates the solid phase and the liquid phase in the mixed liquid. The solid phase is discharged from the knife gate valve. According to the mass of the solid phase passing through the weight sensor below per unit time, the liquid phase is discharged from the liquid phase clear liquid outlet. The mass of the liquid phase is obtained by multiplying the liquid volume by the liquid density. The sum of the solid phase mass and the liquid phase mass is compared with the total mass of the mixed liquid measured by the flowmeter. If the error is within the set range, it can be considered that the solid phase and the liquid phase of the mixed liquid have been completely separated.

[0025] S5. The solid waste residue is re-transported to the storage tank by the belt conveyor, and the liquid phase also re-enters the storage tank through the pipeline for re-circulation and utilization.

[0026] S6. Gradually increase the feed rate of the mixed liquid at a fixed gradient. When the centrifugal load of the horizontal screw centrifuge reaches the maximum value, the torque of the horizontal screw centrifuge reaches the maximum value and it can no longer separate the mixed liquid. The alarm indicator light inside the electric control system flashes. At this time, the mass of the solid waste residue discharged from the knife gate valve is the maximum load of the tested horizontal screw centrifuge.

[0027] S7. The cleaning system cleans the inside of the horizontal screw centrifuge.

[0028] The present invention has the following beneficial effects: When testing the maximum load of separating the solid phase and the liquid phase of a horizontal screw centrifuge in other industries and fields, the centrifuge to be tested can be directly installed in this system, and the material to be tested can be directly introduced from the feeding system. When the centrifugal load of the horizontal screw centrifuge reaches the maximum value, the torque of the horizontal screw centrifuge reaches the maximum value and it can no longer separate the mixed liquid. The alarm indicator light inside the electric control system flashes, and the mass of the solid waste residue discharged from the knife gate valve per unit time is the maximum load of the tested horizontal screw centrifuge. And according to the solid content, the maximum load for this mixed liquid can be obtained. Compared with the existing maximum load data obtained by discharging the solid waste residue, it is more accurate. According to this maximum load, it is convenient to select the horizontal screw centrifuge for different mixed liquids, not only limited to municipal sewage treatment, but also has good development prospects for development in other fields and industries. Description of the Drawings

[0029] Figure 1 It is a schematic diagram of a horizontal screw centrifuge pressure load test system and test method proposed by the present invention.

[0030] Legend Explanation:

[0031] 1. Feed system; 101. Feed pump; 102. Feed pipeline; 103. Flowmeter; 2. Horizontal scroll centrifuge; 3. Solid discharge port; 4. Liquid supernatant port; 5. Discharge system; 501. Belt conveyor; 502. Knife gate valve; 503. Weight sensor; 6. Buffer system; 601. Storage tank; 602. Agitator; 7. Electric control system; 8. Cleaning system; 801. Cleaning centrifugal pump; 802. Cleaning pipeline; 803. Clean water pipeline; 804. Solenoid valve; 805. Check valve. Detailed implementation manners

[0032] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0033] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention; the terms "first", "second", "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In addition, unless otherwise clearly defined and limited, the terms "installation", "connection", and "connection" 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 or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0034] Referring to Figure 1 , an embodiment provided by the present invention: a pressure load test system for a horizontal scroll centrifuge, including a feed system 1;

[0035] The feed system 1 includes a feed pump 101, a feed pipeline 102, and a flowmeter 103, which are used to send the test material into the centrifuge and calculate the feed rate. The test material used in this embodiment is yellow sand, which has good dredging properties. When the horizontal scroll centrifuge 2 is blocked, it can be dredged by reversing or manually to ensure the normal operation of the horizontal scroll centrifuge 2. The solid content of the entire mixed liquid is controlled at 2% through manual cooperation, and the yellow sand is sent into the horizontal scroll centrifuge 2 through the feed pipeline 102 by the feed pump 101;

[0036] The decanter centrifuge 2 for testing is connected to the feeding system 1. In this embodiment, the aspect ratio of the decanter centrifuge 2 is L / D = 4.33, and the feeding method is from the large end. The differential speed of the screw conveyor is 2 - 20 r / min, the inner diameter of the drum is 530 mm, the working length of the drum is 2270 mm, and the maximum rotational speed of the drum is 3200 r / min. Through the high-speed rotation of the rotating body - drum and the discharging screw, the sewage inside rotates at a high speed to form a liquid ring and generate a relatively high centrifugal force. Through the action of this relatively high centrifugal force, the sedimentation separation of solid and liquid is accelerated. Among them, the sludge particles with a relatively high specific gravity settle on the outer ring of the liquid ring layer, that is, a mud ring layer is formed along the inner wall of the drum. The mud is pushed out of the drum by the differential speed between the discharging screw and the drum, and then discharged from the solid phase slag discharge port 3;

[0037] The solid phase slag discharge port 3 and the liquid phase clear liquid port 4 are arranged outside the decanter centrifuge 2;

[0038] The discharging system 5 includes a belt conveyor 501, a mud outlet knife gate valve 502, and a weight sensor 503 arranged below the knife gate valve 502, which is used to weigh the discharged yellow sand and recycle it;

[0039] The buffer system 6 includes a storage tank 601 and a stirrer 602 arranged inside the storage tank 601. The storage tank 601 is respectively connected to the feeding system 1 and the discharging system 5, and is stirred by the internal stirrer 602, which can prevent the solid phase in the mixed liquid from precipitating;

[0040] The electric control system 7 includes a control cabinet, a temperature sensor, a vibration sensor, a speed sensor, a weight sensor, a limit switch, a frequency converter, a relay, an AC contactor, a panel operation switch, a status indicator light, and a display instrument, which is used to monitor and control the feeding system 1, the decanter centrifuge 2, the discharging system 5, the buffer system 6, and the cleaning system 8.

[0041] Furthermore, the electric control system 7 is controlled by a PLC system, and is provided with manual, semi-automatic, and automatic control modes. In the automatic control state, it can fully automatically control the entire process of material dehydration treatment according to the production process requirements. This system can automatically adjust the differential speed between the drum and the screw according to the load change. And it has various abnormal state detection, alarm, and interlock control functions to ensure the reliable and safe operation of the dehydration system.

[0042] Furthermore, a cleaning system 8 is also included, which internally includes a cleaning centrifugal pump 801, a cleaning pipeline 802, a cleaning water pipeline 803, a solenoid valve 804, and a check valve 805, which can clean the entire system after the test.

[0043] Further, the belt conveyor 501 is connected to the storage tank 601.

[0044] Further, all the interfaces connected to the scroll centrifuge 2 in the whole system are quick interfaces. When it is necessary to replace the scroll centrifuge 2 to be tested, it can be replaced quickly.

[0045] Further, a collecting device is arranged below the liquid-phase clear liquid outlet 4, and the collecting device is connected to the storage tank 601 through a pipeline. The liquid phase is discharged from the liquid-phase clear liquid outlet 4 and then flows back to the storage tank 601 through the pipeline.

[0046] Further, the feed pump 101 is a positive-displacement single-screw pump and adopts variable-frequency stepless speed regulation.

[0047] Further, a drive system is externally connected to the scroll centrifuge 2, and the inside of the drive system includes a drum drive system and a screw drive system.

[0048] Further, the inside of the drum drive system includes a motor and a belt drive system. The belt drive system has multiple V-belts, which provide all the load capacity of the equipment and can withstand all the system starting torques. The main motor is a squirrel-cage induction motor with overheat protection. The screw drive system includes a hydraulic pump station and a hydraulic system, and adopts a hydraulic differential. Its output torque is large (2-4 times that of a mechanical differential), and the differential can change according to the load change. The differential automatically feeds back and adjusts, and the pusher power is automatically compensated, so that the solid slag in the machine is not only affected by the centrifugal pressure, but also is bidirectionally extruded between the front two screw blades to ensure the constant dryness of the solid slag, and a drier solid slag is obtained; after discharging the solid slag, the initial differential is automatically restored, and it is not easy to occur the situation of material blockage; when troubleshooting the material blockage fault, there is no need to disassemble the machine. As long as the hydraulic device is started to automatically discharge the slag and remove the accumulated material.

[0049] A test method for a scroll centrifuge pressure load test system includes the following steps:

[0050] S1, mixing the test material with water to obtain the solid content of the mixed liquid and putting it into the storage tank 601;

[0051] S2, installing the scroll centrifuge 2 to be tested into the above system;

[0052] S3, the feed pump 101 in the feed system 1 sends the mixed liquid into the scroll centrifuge 2 along the feed pipeline 102, and the flowmeter 103 in the feed system 1 can measure the feed quantity;

[0053] S4. The horizontal screw centrifuge 2 separates the solid phase and the liquid phase in the mixed liquid. The solid phase is discharged from the knife gate valve 502. According to the mass of the solid phase obtained by the weight sensor 503 below per unit time, the unit time can be set from one hour to five hours. The liquid phase is discharged from the liquid phase clear liquid outlet 4. The mass of the liquid phase is obtained by multiplying the liquid phase volume by the liquid phase density. The sum of the solid phase mass and the liquid phase mass is compared with the total mass of the mixed liquid measured by the flow meter 103. If the error is within the set range, it can be considered that the solid phase and the liquid phase of the mixed liquid have been completely separated, and the horizontal screw centrifuge 2 discharges all the solid waste residues;

[0054] S5. The solid waste residues are re-transported to the storage tank 601 by the belt conveyor 501, and the liquid phase also re-enters the storage tank 601 through the pipeline for re-circulation and utilization;

[0055] S6. Gradually increase the liquid inlet volume of the mixed liquid at a fixed gradient. When the centrifugal load of the horizontal screw centrifuge 2 reaches the maximum value, the torque of the horizontal screw centrifuge 2 reaches the maximum value and it can no longer separate the mixed liquid. The alarm indicator light inside the electric control system 7 flashes. At this time, the mass of the solid waste residues discharged from the knife gate valve 502 is the maximum load of the tested horizontal screw centrifuge 2;

[0056] S7. The cleaning system 8 cleans the inside of the horizontal screw centrifuge 2.

[0057] Working principle: When this system is in use, first mix the test material with water to obtain the solid content of the mixed liquid and put it into the storage tank 601. Then install the horizontal screw centrifuge 2 to be tested into the above system. The mixed liquid enters the horizontal screw centrifuge 2 along the feed pipeline 102 through the feed pump 101 in the feed system 1. The flow meter 103 in the feed system 1 can measure the feed volume. After the mixed liquid enters the horizontal screw centrifuge 2, the horizontal screw centrifuge 2 separates the solid phase and the liquid phase in the mixed liquid. The solid phase is discharged from the knife gate valve 502. According to the mass of the solid phase obtained by the weight sensor 503 below per unit time, the liquid phase is discharged from the liquid phase clear liquid outlet 4. The mass of the liquid phase is obtained by multiplying the liquid phase volume by the liquid phase density. The sum of the solid phase mass and the liquid phase mass is compared with the total mass of the mixed liquid measured by the flow meter 103. If the error is within the set range, it can be considered that the solid phase and the liquid phase of the mixed liquid have been completely separated. The solid waste residues are re-transported to the storage tank 601 by the belt conveyor 501, and the liquid phase also re-enters the storage tank 601 through the pipeline for re-circulation and utilization. Gradually increase the liquid inlet volume of the mixed liquid at a fixed gradient. When the centrifugal load of the horizontal screw centrifuge 2 reaches the maximum value, the torque of the horizontal screw centrifuge 2 reaches the maximum value and it can no longer separate the mixed liquid. The alarm indicator light inside the electric control system 7 flashes. At this time, the mass of the solid waste residues discharged from the knife gate valve 502 is the maximum load of the tested horizontal screw centrifuge 2. The cleaning system 8 cleans the inside of the horizontal screw centrifuge 2.

[0058] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A testing method for a pressure load test system of a horizontal screw centrifuge, characterized in that: The test system includes a feeding system; The feeding system includes a feed pump, a feed pipeline and a flowmeter, which are used to send the test material into the centrifuge and calculate the feed rate; The horizontal scroll centrifuge for testing is connected to the feeding system; The solid discharge port and the liquid supernatant port are arranged outside the horizontal scroll centrifuge; The discharging system includes a belt conveyor, a sludge discharge knife gate valve and a weight sensor arranged below the knife gate valve, which are used to weigh the discharged test material and recycle it; The buffer system includes a storage tank and a stirrer arranged inside the storage tank; The electric control system includes a control cabinet, a temperature sensor, a vibration sensor, a speed sensor, a weight sensor, a limit switch, a frequency converter, a relay, an AC contactor, a panel operation switch, a status indicator light and a display instrument, which are used to monitor and control the feeding system, the horizontal scroll centrifuge, the discharging system and the buffer system; The test method includes: S1, mixing the test material with water to obtain the solid content of the mixed liquid and putting it into the storage tank; S2, installing the horizontal scroll centrifuge to be tested into the above test system; S3, the feed pump in the feeding system sends the mixed liquid along the feed pipeline into the horizontal scroll centrifuge, and the flowmeter in the feeding system can measure the feed rate; S4, the horizontal scroll centrifuge separates the solid phase and the liquid phase in the mixed liquid, the solid phase is discharged from the knife gate valve, and the mass of the solid phase separated per unit time is obtained through the weight sensor below; The liquid phase is discharged from the liquid supernatant port, the mass of the liquid phase is obtained by multiplying the volume of the liquid phase by the density of the liquid phase, and the sum of the mass of the solid phase and the mass of the liquid phase is compared with the total mass of the mixed liquid measured by the flowmeter. If the error is within the set range, it can be considered that the solid phase and the liquid phase of the mixed liquid have been completely separated; S5, the solid waste residue is retransported to the storage tank by the belt conveyor, and the liquid phase also re-enters the storage tank through the pipeline for recycling; S6, gradually increase the feed rate of the mixed liquid in a fixed gradient. When the centrifugal load of the horizontal scroll centrifuge reaches the maximum value, the torque of the horizontal scroll centrifuge reaches the maximum value and cannot continue to separate the mixed liquid. The alarm indicator light inside the electric control system flashes. At this time, the mass of the solid waste residue discharged from the knife gate valve is the maximum load of the tested horizontal scroll centrifuge; S7, the cleaning system cleans the inside of the horizontal scroll centrifuge.

2. The testing method of a pressure load test system for a horizontal screw centrifuge according to claim 1, characterized in that: The test system includes a cleaning system, which includes a cleaning centrifugal pump, a cleaning pipeline, a cleaning water pipeline, a solenoid valve and a check valve inside, and can clean the entire system after the test; 3. The test method of a pressure load test system for a horizontal screw centrifuge according to claim 1, characterized in that: The belt conveyor is connected to the storage tank; 4. The testing method of a pressure load test system for a horizontal screw centrifuge according to claim 1, characterized in that: The interfaces of the test system connected to the horizontal scroll centrifuge are all quick interfaces; 5. The testing method of a pressure load test system for a horizontal screw centrifuge according to claim 1, characterized in that: A collection device is arranged below the liquid supernatant port, and the collection device is connected to the storage tank through a pipeline; 6. The testing method of a pressure load test system for a horizontal scroll centrifuge according to claim 1, characterized in that: The feed pump is a positive displacement single screw pump and adopts variable frequency stepless speed regulation; 7. The test method of a pressure load test system for a horizontal scroll centrifuge according to claim 1, characterized in that: The electric control system is controlled by a PLC system and is provided with manual, semi-automatic and automatic control modes; 8. The test method of a pressure load test system for a horizontal screw centrifuge according to claim 1, characterized in that: A drive system is connected to the outside of the horizontal scroll centrifuge, and the drive system includes a drum drive system and a screw drive system inside.

9. The testing method of a pressure load test system for a horizontal screw centrifuge according to claim 8, characterized in that: The interior of the drum drive system includes a motor and a belt drive system, and the screw drive system includes a hydraulic pump station and a hydraulic system.

Images