4 Clear sediment drain at the bottom of the drain, especially at the bottom of a large diameter permanent pipe borrowed separately settling solid particles. The diameter of these solid particles after repeated sedimentation of water than the larger, spherical surface, more smooth. When the above mentioned centrifugal pump insufficient water, the flow decreased, the flow velocity slowed down, will increase the settlement of solid particles. If the flow of the centrifugal pump is reduced to a certain critical value, the settling solid particles will flow countercurrently down through the valve and fill the pump chamber, which will void the pump in less than a few minutes. We can test it in the field or do a simulation test in the laboratory to verify this phenomenon. To this end, to calculate the minimum flow rate value of the pipeline when the pipeline should generally be greater than 1m / s. To increase the flow rate, should be preferred to use smaller diameter drainage pipe. Taking the example of pipe installation of a submersible submersible pump (see Figure 1), a short pipe may be connected to the pipe between the check valve 1 and the gate valve 4 of the centrifugal pump or to the lowest point of the elevation of the pipe Sand tube. The desilting pipe is controlled by another gate valve 5, which discharges underground in the well when there is a large amount of solid particles in the water. Each discharge of about 0.2-0.3m3 can be. In this way, you can promptly remove the settlement of solid particles in the drainage pipe to prevent accidental wear and tear centrifugal pump. Experience has shown that rock excavation, insisted on regular discharge of sediment during rock out operations, generally extend the service life of centrifugal pumps about 3-10%, and make the pump out there overhaul value, or make overhaul easier. In the automatic drainage, the same should be added regularly remove the bottom of the drain sediment auxiliary equipment, if with the collection of water samples, timely analysis and finishing information, we can develop a more scientific use of the pump maintenance methods to maximize the extension of the centrifugal pump life. Of course, this measure is best used at the design stage. 5 to cancel the balance plate of the new type of sediment submersible pump with multi-stage centrifugal pump centrifugal water directly transported with solid particles of mine water, the main spear has focused on the balance of axial force. Therefore, to extend the life of the pump, remove the balance plate, (or cancel the balance drum) has become an inevitable trend. 5.1 Selection of wear-resistant materials Depending on the application, all kinds of pump parts with different wear-resistant materials. Clean water pump for long life, wear-resistant material is copper alloy; sewage pump starting in the discharge pulp, wear-resistant material is only ordinary cast iron. Slurry pump is a single-stage pump, wear-resistant material is high chromium cast iron; sand pump sand in the river, wear-resistant material is rubber. Visible, "wear-resistant materials," the definition of a wide range. Research and development of multi-stage sediment pumps, to deal with is the hardness, angled "sand", to study the sand in high pressure, high-speed state of the law of pump erosion. Therefore, the choice of "wear-resistant material" is even more important. The following parts of the same material, according to the degree of damage from big to small order: balance disc, impeller mouth ring, packing sets, bushings, vanes, pump body, impeller. As a result, sand pump selection of wear-resistant materials have learned and based on which you can get the following tips: 5.1.1 various wearing parts should use different hardness of high quality materials. Among them, easy to wear the use of high hardness of the material, easy to wear parts with low hardness materials. In this way, both to prevent weaknesses, but also reduce costs. 5.1.2 cancel the highest requirements of the material hardness balance plate. To the highest hardness of the material can be used at present - tungsten cobalt carbide used in the impeller lip and sleeve, in order to obtain the longest service life, the best value for money. 5.2 cancel the balance plate approach - to improve the single-stage pump head, instead of multi-stage pump to improve the single-stage pump lift to replace the previous two-stage, three-stage multi-stage pump, simple and easy. In 1988, with a head 70m, flow 100m3 / h, power 37kw single-stage double-suction suds submersible pump to achieve this desire. The pump is designed for quarrying of Quaternary sediment and then used for remote remote control recycling of coal washery wastewater in the northern North China in winter (3 km away from the old open-air sediment slime). In 1989, this was achieved again with a single-stage single suction sump submersible pump with a lift of 50 m and a flow rate of 12 m 3 / h, which allowed passage through a solid particle with a diameter of 10 mm and a power of only 4.0 kW. Since then, both the impeller and the inner and outer rings of the pump body have been made of cemented carbide. The first alternative to multistage centrifugal pumps in the tunnel excavation face drainage, "life expectancy 5-8 times" (excerpt from the pump 1991 ministerial level "new product certification certificate"). Multistage centrifugal pump was replaced as much as 40kw, its high-pressure water is used to drive the jet pump (commonly known as pump, water pumping) in the downhill drainage. As a result, this small pump is rapidly gaining popularity and has won numerous awards. Hundreds of coal mines with different geological conditions across the country have been tested on site for 10 years, proving that this type of technical solution for submersible submersible pumps is feasible. At present, single-stage sediment submersible pump varieties, uses have been greatly expanded, such as: â‘ used in coal mining face, the technical parameters can be reached: head 95m, flow 168m3 / h. â‘¡ used in driving face, technical parameters can be reached: head 85m, flow 158m3 / h. Efficiency can reach 62.1%. Motor power 75kw. 5.3 Cancel balance plate approach two - Impeller back to back installation, to offset the axial force Impeller number is even, each two impeller mounted back to back, offset each other axial force, is a good way to completely cancel the balance plate. In 1995, a four-stage multi-stage submersible submersible pump to achieve this idea. This pump, once in Gansu, recovered a flooded mine. The mine ground permeable, carrying the Northwest surface sediment into the well, many times with the ordinary centrifugal pump recovery, did not work. The pump technical parameters: Head 200m, flow 80m3 / h, efficiency 59.3%, power 185kw. Nowadays, through unremitting efforts, it has added a number of practical techniques to improve the original design almost completely. Technical parameters have been revised as: head 320m, flow 80m3 / h, power 185kw. 5.4 Sediment submersible pump structure Introduction The above sand submersible pump is vertical, can be placed in place, but also hanging installation. Pump and motor coaxial, the motor in the upper part of the pump in the lower (under the pump). The main features of the structure of the submersible sand pump are: the motor is placed in the "air chamber". The "air room" is like an open "teacup." The "cup" bottom of the cup up, cup mouth down, into the water fixed. At this time, the "cup" of the air will not run away. Place the motor stator, rotor, and upper and lower bearing supports in the "teacup" in advance, and then extend the motor shaft downward from the "cup" port. This is the motor model for the submersible pump. With the "air chamber" protection, the motor stator, rotor, bearings and shaft seals are not in direct contact with water and sediment, acid and alkali salts and other harmful substances. Therefore, the motor will not be damaged even if it is submerged in water with a large amount of sediment. In addition, the motor windings with heat-resistant epoxy casting, curing it for long-term adapt to the underground environment requirements. The motor shell is covered in the "water guide sleeve". The water discharged from the pump all flows between the motor and the water guide sleeve, and the motor realizes "water cooling." In this way, sand submersible pump can be exposed surface work. The above-mentioned sediment submersible pump single-stage single-suction, multi-stage single-suction, single-stage double-suction three forms, eliminating the need for pump shaft casing in the pump important wearing parts - shaft seal, This is because: â‘ single-stage single-suction impeller suction upward, the lower end of the pump is closed. â‘¡ multi-stage single suction head impeller at the top, the first stage impeller suction upward, the lower end of the pump is closed. â‘¢ single-stage double-suction impeller has two suction ports. Allow water to run dry - no damage to the motor and pump body. With water, you can continue to drain, without someone waiting. This requirement, from the coal mine line, made by the Shanghai Branch of Coal Research Institute made after making the design of the submersible sand pump at the beginning of this valuable subject to tackle key issues, with its unique structure, in the first product It was born. When leaving the factory, idling test must be made in Taiwan, even 75kw, 185kw nor out. In coal mines are modern, mechanized and equipped themselves today, people have begun to imagine the drainage automation. Demand for "water tank" pump, the demand along the roof dredging, automatic drainage in the low waterway pump, demand in the explosive environment of the use of large-scale desilting submersible pumps, and so on, louder and louder. Therefore, "multi-stage sediment pump" research has received widespread attention. Since the advent of submersible submersible pumps, many design institutes, large and medium-sized coal mines have worked together to make bold attempts to contribute to this new life.
PVC Wood Plastic Board,PVC Decking Boards,PVC Wood Board,1X6 PVC Board
Linyi Fengzhize Trading Co., Ltd. , https://www.fengzhize.com