China Mixed Flow Pump

Mixed flow pumpA. Overview1, use: HW (HBC) series mixed flow pump is a horizontal single-stage single-suction volute type mixed flow pump with calibers of 100, 150, 200, 250, 300, 350, 400, 500, 600, 650, 700, 800, and the flow rate is 60~. 9000 m 3 / h, the head is 3 to 20 meters. The whole series of products are designed for front and rear, and there is no need to dismantle the pipeline during maintenance. This is a major improvement on the structure of the mixed-flow pump produced by our company, which greatly facilitates the user's maintenance and repair. The water inlet of the pump is horizontal water inlet, and the water outlet has vertical water discharge (upper water and horizontal water (lower water)). The pump is usually installed in horizontal suction type or inclined type. For down-center installation, users can choose according to design requirements and local water level changes and usage habits.
It is suitable for conveying clean water or other liquids with physical and chemical properties similar to water. The temperature of the liquid to be transported should not exceed 50 °C. Widely used in a variety of occasions such as irrigation and drainage, industrial and urban water supply and drainage.2. Features:The utility model has the advantages of simple structure, reliable use, convenient assembly and disassembly, small body shape, light weight, large flow rate and high efficiency.
3. Transmission mode:There are two types of direct drive and belt drive. Commonly used power machines are electric motors and diesel engines. When ordering, indicate the type (power, speed) of the power machine to determine the specifications of the pulley or coupling.4. Pump steering:From the pump inlet, the impeller rotates counterclockwise.5, model description:: Take 300HW-7S as an example:
300--Pump diameter, outlet diameter. Unit: mm
HW--Horizontal volute mixed flow pump.
7--Design the lift. Unit: m
S--Structure form (front and rear door opening structure).6, using standards:HW-S type pump adopts GB/T13008, JB/T6667 standard design, manufacture and acceptance.B. Structure and use1. HW-S type mixed flow pump is mainly composed of main parts such as pump cover, impeller, pump body, pump shaft, bushing, packing seat and bearing body (bearing frame). It adopts the structure of front and rear door opening.
2. The pump cover is connected to the pump body and the inlet pipe respectively. There should be a suitable gap between the plane of the pump cover and the plane of the impeller. If the gap is too small, friction is easy to occur; if the gap is too large, the pressure water in the pump body will flow back a lot, which will reduce the efficiency of the pump. The appropriate clearance for practical use is 0.3 - 0.7 mm (measured by pushing the pump shaft toward the inlet end of the pump) and the clearance can be adjusted by increasing or decreasing the thickness of the paper pad.
3. The packing sealing structure of the shaft sealing device. Its function is to prevent air from absorbing into the pump and preventing water from flowing out of the shaft excessively from the pump.
4. The bushing is used to protect the pump shaft and can be replaced in time after wear.
5. The pump shaft is supported by a single row radial ball bearing. The bearings can be lubricated with lubricating oil. The oil quantity should be controlled between the marking lines of the oil standard rod. It can also be lubricated with grease. It can be added when assembling the water pump. It can be replenished by disassembling the front cover and the back cover during use.
6. The screw hole at the upper end of the pump body is used for watering or water pumping and vacuum pumping, and the screw hole at the lower end is used for water discharge.
7. In order to expand the range of use of the pump and meet different requirements of users, it can be replaced with impellers of different performances.C. Main technical parameter conversion1, pump performance conversion:
(1) Changing the speed of the pump can change the performance of the pump and expand the range of use of the pump.
(2) Method of changing the speed: change the outer diameter of the pulley or change the gear ratio of the gear reducer. You can also use a power machine with different speeds.
(3) After the pump speed is changed, the relationship between the flow rate (Q), head (H) and power (N) is as follows:
Q1=Q*n1/n H1=H*(n1/n)2 N1=N*(n1/n)3
Where: Q1, H1, N. Represents flow, head and power after the speed change.
Q, H, and N represent the flow rate, head, and power at the specified speed, respectively.
(4) After the pump speed is increased, the power consumption is increased, the suction vacuum is reduced, and the life is shortened. Excessive increase in speed will cause other accidents, so it should be used with caution.
(5) When the pump speed is excessively reduced, the use efficiency of the pump is low. To this end, the pump should be prevented from operating at too low a speed. Users should choose to use according to the performance graph.
2. The conversion relationship between the suction degree [Hs] and the required NPSH [NPSH]r is allowed:
[Hs]≈10-[HPSH]c
[NPSH]r≈[NPSH]C+0.3
Where: [Hs] - allow vacuum to be applied
[NPSH]C-critical NPSH
[NPSH]r-Required NPSHD. Performance parameter table
E. Pump installationThe HW-S type pump has three types of installations: full-fall, semi-falling and floor-standing. Semi-falling installations sometimes reduce the high suction installation and the increased loss due to the long inlet line.
1. Installation principle:
(1) Installation height of the pump: The highest upper water level should not be higher than the lower end of the bearing. The lowest lower water level depends on the allowable vacuum of the pump (the pipeline loss should be subtracted).
(2) The water pump should be as close as possible to the water source to shorten the water inlet pipe and reduce the pipeline loss.
(3) The pipeline should be as straight and short as possible. Generally, a 90° or 33° elbow is used at the water inlet, and the water pump foot base is inclined, which can save the water outlet bend.
2, note:
(1) When driving with a belt, the pulleys of the water pump and the power machine should be positive. A safety cover is required outside the pulley and belt.
(2) The pump cover should not be directly connected to the elbow. The straight pipe should be connected first and then the elbow should be connected to ensure uniform flow velocity at the inlet.
(3) Rubber pads or asbestos wires should be added between the connecting flanges of the pipeline to prevent air leakage and water leakage.
(4) The position of the inlet pipe into the pool should be appropriate. The inlet pipe is generally 1D-3D from the bottom of the river.
The minimum dry water surface is generally 1D-3D, and the inlet pipe is generally (1-1. 5)D (D is the inlet pipe diameter). The small pump takes a large value and the large pump takes a small value.
(5) The water outlet should be submerged in the water of the water outlet and as close as possible to the water surface to reduce the head loss.
(6) A net cover shall be provided in front of the water inlet to prevent the grass debris from entering the pump to break the impeller or block the flow path.
(7) When the pump is installed on the ship and lubricated with lubricating oil (thin oil), it should be abused to the lowering of the bow caused by the pump when pumping water or the hull of the hull. It is necessary to ensure that the pump shaft maintains a horizontal position during operation to avoid The bearing is damaged due to lack of oil.
Sixth, use and maintenance
1, test drive:
After the pump is installed, it needs to be commissioned to check the pump's steering and eliminate problems in the installation.
2. Driving sequence:
(1) Close the outlet gate valve or check valve.
(2) Add water: add water from the screw hole at the top of the pump body, or open the check valve to make the water in the water tank overflow and add water, or use the vacuum pump to pump water (when the vacuum pump draws out the air inside the pump, after pumping out the water) , you can start the pump and stop the vacuum pump).
(3) When the power machine reaches the normal speed, open the gate valve and adjust the tightness of the packing. Such as pump operation and shaft
If the temperature is normal and the vibration is slight, it can continue to operate (use the check valve, the valve cover should be lifted after the water is discharged to reduce the resistance).
3. Use and maintenance;
(1) When the bearing is lubricated with thin oil, the oil level of the bearing body should be checked and controlled frequently on the two standard lines of the oil standard rod; when the bearing is lubricated with grease, the oil should be replenished at regular intervals. The front cover and the back cover are removed from the pump to replenish.
(2) Always check the temperature rise of the bearing. Generally, it should not be higher than the ambient temperature of 40 ° C, and the maximum temperature should not exceed 80 ° C.
(3) Pay attention to the friction and impact sound when the pump is running. If the pump cover rubs against the impeller, a paper pad can be added between the pump cover and the pump body. The actual use clearance is 0.3 - 0.7 mm.
(4) The adjustment of the packing must be appropriate, and the liquid should leak intermittently from the packing gland. The packing is too tight, the shaft will heat up and the power will increase; the packing will be too loose, the liquid will leak too much, and the efficiency will decrease.
(5) If the motor and pump should be connected, the axis of the two axes should be in a straight line.
(6) Check the water inlet pipe for air leakage.