The 230m horizontal central pump room is designed by our mine engineering technicians. Three 150D30X9 pumps were used. The flow rate was 155m3/h. The maximum suction vacuum height was 6.6m. The two main drainage pipes used seamless pipes of 6194X6.5mm and 6219X6mm seamless pipes as suction pipes. The actual speed of the water flow in the drain pipe is 1.95m/s; the flow rate of the water in the suction pipe is 1.4m/s. The motor of the pump is selected and the pump is equipped with a JR126*4/225kw motor, and the speed is 1480r/min. The experience of using it for many years in the Hetai Gold Mine Considering that one end of the valve is used for more harm, the bottom valve is replaced with a vacuum tank instead of a bottom valve.
2 The structural requirements of the vacuum tank and the participation of the centrifugal water pump vacuum water tank are composed of the box body, the water inlet pipe, the outlet pipe, the water injection valve and the water injection cup (as shown). The box body is made of A3 steel plate rolled and welded with mm thickness. According to the experience, the volume of the box is more than 4 times the capacity of the suction pipe to meet the requirements. In order to achieve the sealing effect, the welding of suction pipes, drain pipes, and various water injection pipes and cleaning nozzles should meet the corresponding stringent requirements to ensure that no leakage occurs. In order to ensure airtightness, the suction pipe and the drain pipe can infiltrate into the tank much better. It is advisable that the suction pipe submerges into the tank body to the bottom of the tank at a distance of 250mm. It is advisable to insert the drain pipe into the tank body at a distance of 150mm from the bottom of the tank. This is to ensure the sealing performance. It can also reduce the box production requirements. When the vacuum box is in use, the water injection pipe is connected with the main drainage pipe, and the pump body and the water tank are filled with water through the injection valve. In the normal operation condition, the water injection cup is used. 6. Cleaning pipe 1: Zhao Ruimin (1964-) Male. Assistant Engineer W, t is engaged in gold mechanical technology and management work. A11u. A. No water injection is required. Water injection is only required when the water in the tank is drained. The water injection cup is used only for initial water pumping. The cleaning tube can be sealed with a wire plug and used for cleaning sludge and other impurities due to prolonged application. As a vacuum tank is used instead of the bottom valve, a suction filter should be installed at the end of the suction pipe to prevent debris from entering the pump body and causing a malfunction.
3 Principle analysis of the vacuum tank to replace the bottom valve of the pump Centrifugal pump is a kind of fluid machine for conveying liquid. It is relying on the rotary impeller to work on the liquid to transfer the mechanical energy of the prime mover to the liquid, so that the energy of the liquid (bit energy, pressure) Energy and speed can be added. Centrifugal water pump main components are the impeller, which has a certain number of blades, the impeller is fixed on the shaft, driven by the shaft rotation, when the pump is started, the impeller is rotated with the pump shaft, injected into the water flow between the leaves, in the Under the dynamic action of the blade, it is rotated forward. After the water deflector of the pump, most of the speed can be converted into pressure energy and then sent out along the drain pipe. At this time, a vacuum is formed at the inlet of the impeller due to the discharge of water, and the water in the water absorption well is pressed into the inlet of the impeller under the action of the atmospheric pressure. Thus, the rotating impeller continuously sucks in and discharges water. When the pump is started, the pump body and the suction pipe are required to be vacuum. The bottom valve installed in the water filter at the end of the suction pipe is a one-way valve. When the water is poured into the pump or the pump is stopped, the valve is closed. The water poured into the pump fills the pump body cavity and the suction pipe without leaking. When the pump is started, the water in the pump chamber is discharged to form a vacuum. The water in the water absorption well under the pressure of the atmospheric pressure pushes the valve core of the bottom valve and is pressed into the inlet of the impeller. As a result, water is continuously sucked in and discharged. The so-called vacuum tank bottomless valve pump, that is to say the bottom of the pump suction pipe to remove the one-way check valve installed before starting the irrigation water. The working principle is that when the pump is running, the water in the vacuum box is first suctioned. Since the water in the tank is discharged in a short time, a certain vacuum is formed in the vacuum box, and the water in the well under the action of the external atmospheric pressure enters the vacuum box through the suction pipe to ensure the normal drainage of the pump. If the water injection process is sufficiently large, the air in the suction pipe will be mostly discharged, so that the pump body and the vacuum tank body and water will be pressed into the tank and the pump impeller under the action of atmospheric pressure. The rotating impeller The water is continuously sucked in and discharged.
4 Vacuum tank replacement bottom valve performance parameters checking The bottom valve set in the water filter on the centrifugal pump suction pipe not only adds pipe resistance, increases the energy consumption, reduces the pump efficiency, but also reduces the water pump height . Three 150D30X9 water pumps equipped in the 230m central pump room of Takamura are vacuum-assisted. The vacuum conditions are the same as those of the bottomless valve. Therefore, the calculation of the parameters is the same as that of the bottomless valve. The calculation process is as follows: (1) Drain pipe flow resistance loss.
Into a one-way resistance loss coefficient to take 0.0312.; lp sum: suction pipe flow resistance loss.
The sum of the coefficient of resistance loss along the way to take 0.0301; lx- suction pipe length 8m, dx suction pipe vacuum degree of good guidance. The speed of the water in the PublMing suction pipe in the well (m/c!) http://ww. The sum of the local resistance loss coefficient of the suction pipe fittings; two 90* elbows; the total resistance loss of the water pipe. Hw 3"552=0.0006.H=233.8+0.0006Q2. According to the characteristic curve of the pipeline and the performance curve of the selected 150D30X9 water pump, draw the same proportion on the same Q-H coordinate to obtain the working point: Flow Qm=179m3 /h, Head Hm = 250m, Efficiency n = 0.75. Both are in a better working condition of the water pump: Hsy--The height of the pump's geodetic surface; Q 5 Application effect of the vacuum device The effect of the vacuum device on the centrifugal water pump is mainly manifested in The following aspects: The pump in operation is often caused by the poor quality of the bottom valve or debris into the water filter, so that the bottom valve is not tightly sealed, the water pump can not be diverted without diverting water. The vacuum tank does not exist, its It is a bottomless valve.
Because the underground water is corrosive, the bottom valve is easily damaged. During the inspection and replacement of the bottom valve, the working conditions are harsh and the labor intensity is high. The vacuum tank is installed on the well and the personnel can handle it without going downhole.
Since the vacuum tank has no moving valve parts, the resistance of the pipeline is reduced, the energy consumption is reduced, the pump efficiency is increased, and the water absorption height of the water pump is increased relative to the bottom valve (the vacuum of the water suction port of the water pump is reduced at the same water absorption height). Degree, reducing the possibility of cavitation in the operation of the complex and easy to cause damage to the valve core and the sealing joint wear and tear caused by the water pump can not start.
Because it is a bottomless valve, the operator sometimes operates improperly. When the pump is stopped, the brake shoe does not close tightly. When the check valve fails, the return hydraulic force is also compared with the bottom pump of the jet pump. The operation is simple and the operation is stable. The water can be filled in time; maintenance is convenient; in the case of high-pressure water, bottomless valve drainage can also be realized; there is no injection pump because the injection volume is insufficient, the injection pump cannot work, the hydraulic impact is too strong and the injection pump and the nozzle are easily damaged. Failure occurred. However, the use of a vacuum tank requires an increase in the suction range, which is slightly greater than the power consumption of the jet.
Saving investment, vacuum tank production process requirements are not high, as long as the welding site can meet the requirements of non-leakage, materials do not have to purchase, can be directly processed at the production site, workshop, a bottom diameter DN200 valve requires a few thousand dollars, and Not durable. However, a vacuum tank for supporting production can be completed in only a few hundred dollars.
Low-head drainage can be automated without automatic valves. If used with automatic valves, it can be automated in high-lift rows.
Power saving effect is ideal. Through actual measurement, the bottom valve pump discharges 155m3 of water and consumes 148.87kw.h; while the bottomless valve pump has 155m3 of water per row, the electricity consumption is 137. 7 water can save 11.11kw.h. The daily displacement is calculated as 2000m3. Bottom-valve energy saving 143. The promotion of practicality, can be widely used in mines and factories and other places where the application of centrifugal pump drainage. Our mine has been promoted and used in the No. 0 Central Pumping Station of Gaocun, the Central Pumping Station of 230m, the pumping room of +10m of Yunxi, a pump room of 140m, and other places on the ground and underground. No vacuum has appeared for several years. Device problems have affected the problem of normal drainage.
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