Introduction To Slurry Pumps

I. Overview Slurry pumps belong to centrifugal pumps in terms of working principle. Conceptually, they refer to a machine that increases the energy of solid-liquid mixed media by using centrifugal force (rotation of the pump's impeller), and converts electrical energy into kinetic energy and potential energy of the medium. In addition, slurry pumps can be divided into different types from different perspectives. In addition to pumping water, water pumps can also pump gas, solids, and solid-liquid mixtures - mineral powder slurry! The proportion of electricity used by water pumps in the country's total electricity consumption is very large. The energy saving of water pumps has an important impact on the national economy. Water pumps not only play an active role in the energy-saving link, but also play an important role in the emission reduction process of thermal power generation. Slurry pumps not only save 4%-8% energy than similar products, but also contribute to the atmosphere's escape from the "claws" of haze. Slurry pumps can be divided into single-stage/multi-stage, single-suction/double-suction, cantilever, horizontal/vertical, and horizontal split/vertical combination of pump casings according to different principles. Mainly applicable to: mining, power plants, dredging, metallurgy, chemicals, building materials and petroleum industries. The name of the slurry pump is a centrifugal pump classified from the perspective of the conveying medium. 2. Type classification: Divided from the number of impellers: single-stage slurry pump and multi-stage slurry pump. Divided from the position of the pump shaft and the horizontal plane: horizontal slurry pump and vertical slurry pump. Divided from the way of water inhalation: single-suction slurry pump and double-suction slurry pump. From the structure of the pump shell: single-shell slurry pump and double-shell slurry pump. 3. Performance parameters: Speed: Direct drive by motor 2900/1480/980/730/590 r/min Indirect drive by pulley meets customer requirements Medium temperature: Generally ≤80℃, special up to 110℃ Weight concentration of solid mixture: mortar concentration ≤45% ore slurry concentration ≤60% Flow range: 30-2000m3/h Lift range: 15-130m 4. Common faults: (1) Pump does not rotate; (2) Insufficient pump flow; (3) Leakage at the packing; (4) Pump vibration and noise; (5) Bearing heating; (6) Short bearing life. 5. Treatment measures (1) If the solid and hard sediment in the volute is blocked, measures can be taken to remove the blockage. (2) If the impeller or the inlet and outlet pipes are blocked, the impeller or pipes can be cleaned. If the impeller is severely worn, it should be replaced. If there is air leakage at the packing port, the packing should be compressed. The conveying height is too high, and the loss resistance in the pipe is too large. Reduce the conveying height or reduce the resistance. In response to these fault causes, Xinfengda Pump Factory uses advanced technology to develop a variety of slurry pumps with advantages such as wear resistance, corrosion resistance, high head, and large flow rate. They are widely used in various fields. (3) If the shaft and the feed box are not on the same axis, the main reason is large processing error and incorrect installation. Pay attention to check whether the installation is correct after installation. If the sealing water ring is severely worn, a new water ring needs to be replaced. If the sealing clean water pipe is blocked, the sealing water cannot enter the middle of the packing, causing the packing to wear quickly and cause leakage. The blocked water pipe should be unblocked to keep the sealing water clean. (4) There are mainly 5 reasons: ① Uneven medium density. Uneven medium density causes vibration when the pump is just started. When the pump is turned on normally, the vibration of the pump will disappear. This situation does not need to be handled. Just pay attention to blowing the medium evenly with high-pressure air before driving; ② The pump is not installed horizontally. The level of the pump body should be checked during installation and operation. ③ There is cavitation, which makes the pump impeller unbalanced. The installation height should be lowered, the outlet valve should be adjusted smaller, and the inlet resistance should be reduced. ④ The air intake of the suction pipe is uneven. The feed condition of the pump should be improved to enhance the uniformity and stability of the air intake. ⑤ The pump bearing clearance is large. Excessive bearing clearance will cause large vibration of the pump. During daily equipment operation, the pump should be carefully observed. If the pump shaft and motor shaft are not concentric or the bearing is damaged, it should be handled in time. (5) There are mainly 5 reasons: ① The cold water is not turned on or the cooling water tank is blocked. The cooling water function should be turned on or the cooling water channel should be unblocked. ② The equipment is not lubricated well. The amount of lubricating oil should be adjusted according to the instructions. ③ The lubricating oil is not clean and there are impurities in the oil. The bearing should be cleaned and the lubricating oil should be replaced. ④ The thrust bearing direction is incorrect. According to the inlet pressure, adjust the thrust bearing direction. ⑤ The bearing outlet is blocked, resulting in the inability to discharge the hot air in the bearing box, causing the equipment temperature to rise. The outlet should be cleaned. (6) There are mainly four reasons: ① The motor shaft and the pump shaft are asymmetrical or not parallel. The motor shaft or pump shaft should be adjusted. If the shaft is deformed or bent, replace the shaft directly. ② The bearing assembly is unreasonable. Reinstall the bearing and shaft, or replace the bearing. ③ There is friction in the pump or the impeller is out of balance. The friction should be eliminated or a new impeller should be replaced. ④ Poor lubrication. Excessive, insufficient, or impurities will shorten the bearing life. The bearing should be removed and cleaned before use. VI. Precautions: When the slurry pump is working, the pump needs to be placed on land, the suction pipe is placed in the water, and the pump needs to be primed and started. Due to structural limitations, the motor of the mud pump and the submersible slurry pump needs to be placed above the water surface and the pump is placed in the water when working. Therefore, it must be fixed, otherwise, the motor will fall into the water and cause the motor to be scrapped. In addition, since the length of the long shaft is generally fixed, the pump installation and use is more troublesome, and the application occasions are subject to many restrictions. If there is a spare pump, the two pumps are used in turn. If the pump is stuck, you can only repair it. You can add a net at the water inlet to prevent too many impurities from entering the pump, so the chance of the pump getting stuck will be much smaller! The pump should be divided into two aspects: electrical and mechanical. For the mechanical aspect, you can check the previous maintenance records and compare them. The second is the electrical aspect. You need to understand the power of each pump motor and have a certain understanding of its control system. For slurry pumps with mechanical seals, the supply of shaft seal water must be guaranteed. It is strictly forbidden to operate without water, otherwise the mechanical seal will burn out. VII. Daily maintenance: 1) The water pressure and water volume of the bearing must meet the regulations. Adjust (or replace) the tightness of the packing to avoid leakage of the shaft seal. Replace the sleeve in time. 2) When replacing the bearing, make sure that there is no dust in the bearing assembly and the lubricating oil is clean. When the pump is running, the bearing temperature is generally not more than 60-65℃, not more than 75℃. 3) Ensure the coaxiality of the motor and the pump, and ensure that the elastic pad in the coupling is complete and correct. If damaged, it should be replaced in time. 4) Ensure that the pump components and piping system are installed correctly, firmly and reliably. 5) Some parts of the slurry pump are vulnerable parts. In daily use, pay attention to the loss of vulnerable parts and repair or replace them in time. During the repair or replacement of vulnerable parts of the slurry pump, ensure that the assembly is correct and the gap is adjusted reasonably to avoid the occurrence of tight friction. 6) The suction pipeline system of the slurry pump must be leak-free. At the same time, pay attention to whether the suction port is blocked during operation. The medium that the slurry pump needs to handle mostly contains solid particles. Therefore, the grille placed in the pump inlet pool should meet the requirements of the particles that the slurry pump can pass, reducing the possibility of blockage caused by oversized particles or long-fiber materials entering the pump body.