When the prime mover driven impeller rotation, the centrifugal force of the liquid but also the role of both the axial thrust, centrifugal and axial flow pump is integrated, diagonal liquid outflow impeller. Therefore, it is between centrifugal pump and axial pump.Its head is higher than the axial flow pump.
The structure of mixed-flow pump is between centrifugal pump and axial flow pump. Its head is moderate,traffic is high, scope is wide. It plays a good role in plain river network areas and micro-mound area.
Due to different water chambers,mixed-flow pump has two types-volute type mixed flow pump and diffuser type mixed flow pump. Volute type mixed flow pump has horizontal and vertical, and the horizontal pump apply more. Guide vane mixed flow pump also has horizontal and vertical, in which the vertical mixed flow pump is similar to vertical axial flow pump.
Compared with horizontal centrifugal and axial flow pump,mixed-flow pump has low head, high traffic,so the shape of impeller is special. Since the inlet diameter and outlet diameter of impeller has little difference, the ratio of the diameter of the outlet flow channel width is relatively large, therefore the relative width of volute is larger than the centrifugal pump.
Pump is activated when the electric pump is running, the rotation should be smooth and free of vibration and abnormal noise, observe whether significant fluctuations around the motor running current and line voltage start. After the motor main circuit is energized, the motor does not rotate if found, should be shut down immediately to prevent long power motor stuck and burned. Note that for the first time after installation or repair of pumps in operation, when the test machine can only start in place after the water pump abnormality if found, should be immediately shut down, check the direction of rotation is correct, if installed properly, find the cause and put into operation before troubleshooting. Due to the motor windings burned causing rewind pump, first put into operation after a few hours, you can stop measuring thermal insulation resistance should be not less than 0.38M12 to continue. Should not be open when the pump is running stops too frequently; the number of starts per hour is generally not more than six times, and requires evenly spaced. After 300 hours use of a new water pump,all butter oil in the bearing box should be replaced with new oil.
1) Check if the self-priming pump tubing and junction is loose. Turn the pump by hand or tool, then to observe if the sewage pump is flexible.
2) Try to control the inner self-priming pump flow and head on the plate indicated range to ensure self-priming pump at maximum efficiency point operation. Transfer to achieve maximum energy savings.
3) When self-priming pump is in operation, the bearing temperature can not exceed the ambient temperature of 35C, and the maximum temperature can not exceed 80C.
4) If the priming pump is found with abnormal sound, you should stop immediately to check the reason.
5) When you want to stop using sewage pump, turn off the valve, pressure gauge first, and then stop the motor.
6) When self-priming sewage pump is in a long time using or used in the winter, after stopping, need to unscrew the lower part of the pump drain plug, The media put the net. Prevent cracking.
7) Carefully listen if the sound operation of the motor is abnormal, because the runtime engine room noisy, by means of a screwdriver or listen rods and other aids, posted pro motor ends listen, if you often listen to, not only find bad vibration motor and drag devices, can even determine how much oil inside the bearing, thus adding timely bearing oil, or replaced with new bearings and other appropriate measures to deal with, to avoid motor bearing short of oil and dry grinding stall, walk cylindrical, sweep chamber burned.
1. The pump should be placed in a sturdy basket and put into the water, or a strong protective fence should be set up around the pump. The pump should stand upright in the water, the water depth should not be less than 0.5m, and should not be used in the mixed water containing sediment.
2. If the pump is put into the water or raised the water surface, the power should be cut off first. Do not pull the cable or the water outlet.
3. The pump shall be equipped with zero-connection protection and leakage protection devices, and shall comply with the relevant provisions of “other electric construction machinery” in the “Safety Technical Specifications for Temporary Electricity Use at Construction Sites” of the Ministry of Construction. No water or animal can enter the water within 30m around the work. Nanjing lanshen Pump Corp.LTD., is a major manufacturer of submersible pumps and centrifugal pumps for domestic research and production. The main products are well submersible electric pumps, small submersible pumps, centrifugal pumps, sewage pumps, submerged pumps, pipeline pumps, etc. More than 50 series, more than 800 specifications of pump products, widely used in farmland irrigation, industrial and mining water supply , plateau mountain and human water, municipal construction, high-rise water supply and metallurgy, electric power, petrochemical, environmental protection and other industries. Product quality is in a leading position in the same industry across the country, and sales services have formed a network throughout the country.
The choice of the submersible pump before use is very important. Consider the actual situation of the water source, working time, pumping volume, etc., and comprehensively determine the model of the submersible pump selected. Just like the requirements of the environment, it is necessary to have a safe and reliable power supply, the drop of the outlet pipe on the water surface of the pool is less than the lift, and the water source is preferably clean. When the submersible pump is in normal use, it will inevitably lead to many unexpected situations. In any case, should the submersible pump be stopped immediately?
1) The submersible pump current is unstable and suddenly exceeds the rated current of the motor.
2) If the insulation resistance of the motor is less than 0.5 megohm, the grid voltage is insufficient and less than 5% of the rated voltage.
3) The amount of water is not normal, the intermittent water is discharged, and the sediment concentration is increased.
4) The fuse is burned out and the water supply line is damaged.
5) The unit has obvious noise and vibration.
What inspections need to be done before deep well pump goes down
1. The corresponding plane of the well pipe nozzle protruding from the foundation should not be less than 25 mm;
2. The inner diameter and verticality of the well pipe should meet the requirements of the pump’s entry into the well. The inner diameter of the well should generally be about 50 mm larger than the maximum dimension of the pump into the well, so that the pump body can be freely up and down in the well and must not damage the submersible cable. ;
3. There should be no sludge, dirt and debris in the well pipe;
4. The size of the top middle void of the foundation shall meet the requirements for the connection of the lift pipe to the pump base;
5. Lifting water pipe should be straight, thread and flange end should not be bruised, and should be cleaned;
6. Place a soft barrier between the well pipe and the foundation, such as a rubber septum.
After assembling the hub of the pump on the shaft, the verticality and concentricity of the hub and the shaft should be carefully checked. Generally, two dial indicators are arranged on the end surface and the outer circumference of the hub. When the disk drive rotates the shaft, the value of the full run-up (including the end runout and the radial runout) of the hub is observed to determine the perpendicularity between the hub and the shaft and the coaxiality Degree of the situation. Different speeds of the coupling requirements of full beating different, different types of coupling requirements for full beating also vary, but after the assembly of the hub in the shaft, you must make the hub full runout deviation in the Within the design tolerances, this is one of the major quality requirements for coupling assembly.
Submersible pump assembly caused by the wheel full run-out value does not meet the requirements for many reasons, first of all may occur in the manufacturing process due to the error for the field assembly, mainly due to improper handling of the hub hole surface modification, the hub and shaft concentric Degree of deviation. Another reason is that when a keyed shaft coupling is assembled, the hub and the shaft are not coaxial due to incorrect key assembly. The correct installation of the key should make both sides of the key and the keyway closely fit the wall, usually with the paint color inspection assembly, with the bad file can be used to repair the file or blade to meet the requirements. The upper part of the key generally gap, about 0.1-0.2mm or so. High-speed rotating machinery requires high concentricity between the hub and the shaft. High concentricity can not be obtained by a single-key connection. Concentricity can be improved by using a double-key connection or a spline connection.
The pump transmits the mechanical energy or other external energy of the prime mover to the liquid to increase the liquid energy, which is mainly used to transport the liquid including water, oil and acid-base liquid. Pumps are divided into different categories according to different conditions, and each pump has its own unique method of use. Now we will explain why the centrifugal pump to close the valve start, and axial flow pump to open the valve to start. The reasons are as following:
1.Centrifugal pump power performance curve is a slow rise of the approximate straight line, the minimum shut-off power, in order to start and stop light load, solid start and shut down before shutting down the first outlet valve;
2.The axial pump power performance curve is a rapid decline of the convex convex parabola, the maximum power to turn off the death, in order to avoid wrong operation caused serious overloading of the power machine, axial pump pumping device does not allow any valve.
(1) To ensure smooth flow of the pump, good lubrication.
(2) Submersible pump pressure, flow stability, normal temperature in all parts, no high temperature, current stability.
(3) Pump runs smoothly without abnormal vibration, noise and so on.
(4) Stable operation within the range specified on the nameplate performance index.
Some manufacturers will have some very special requirements for their own pumps. Then it is in the procurement, there may be a certain demand for high temperature. If the use of the process, 300 degrees or so there is no way to use the temperature, then he for the overall production, may not play a big role. So some of the production enterprises, in the process of submersible sewage pump procurement process, the most need to take into account the problem is its high temperature performance.
In fact, we will find that this equipment in the production and processing, because it can use a different material for production, and he has a lot of accessories, in the production process, you can also use some very high temperature materials, So we buy it, as long as their choice of this production material, it has a certain high temperature resistance, then buy their own back to the sewage pump, it can have a certain high temperature function.
So in the process of buying the submersible pump, as long as all of his materials can be high temperature, then it is in the course of the use of high temperature effect. Enterprises in the procurement, you can be very confident to buy it, to ensure that the use of the latter part of the process, there will be no security problems occur.