Introduction To The Performance Of Vertical Centrifugal Pumps
Dec 24, 2024
Centrifugal pumps, I believe everyone is familiar with them. The content of this article today is also related to centrifugal pumps. Below, we will briefly explain the knowledge of vertical centrifugal pumps, hoping that everyone can learn relevant knowledge.
The main control parameters selected for vertical centrifugal pumps are the flow rate Q, head H, efficiency η, power, speed n, working pressure, and necessary cavitation margin (NPSH) of the water pump.
Structural characteristics of vertical centrifugal pump:
1. A single-stage vertical centrifugal pump is a vertical structure with the same inlet and outlet diameters and located on the same centerline. It can be installed in pipelines like a valve, with a compact and beautiful appearance, small footprint, and low construction investment.
2. The impeller is directly installed on the extended shaft of the motor, with a short axial dimension and compact structure. The pump and motor bearings are reasonably configured, which can effectively smooth the radial and axial loads generated by the pump operation, thereby ensuring the smooth operation of the pump, no vibration, and low noise.
3. The shaft seal adopts mechanical seal or a combination of mechanical seals, using imported titanium alloy sealing rings, medium-sized high-temperature resistant mechanical seals, and hard alloy materials for wear-resistant seals, which can effectively extend the service life of mechanical seals.
4. Easy installation and maintenance, no need to disassemble the piping system.
Vertical centrifugal pump product features:
1. The vertical centrifugal pump is a vertical structure with the same inlet and outlet diameters and located on the same centerline. It can be installed in pipelines like a valve, with a compact and beautiful appearance, small footprint, and low construction investment. If a protective cover is added, it can be used outdoors.
2. The impeller of the vertical centrifugal pump is directly installed on the extended shaft of the motor, with a short axial dimension and compact structure. The pump and motor bearings are reasonably configured, which can effectively balance the radial and axial loads generated by the pump operation, ensuring smooth operation, low vibration, and low noise of the pump.
3. The shaft seal adopts mechanical seal or a combination of mechanical seals, using imported titanium alloy sealing rings, medium-sized high-temperature resistant mechanical seals, and hard alloy materials for wear-resistant seals, which can effectively extend the service life of mechanical seals.
4. Easy installation and maintenance, no need to disassemble the pipeline system, just remove the pump coupling nut to extract all rotor components. Introduction to the Performance of Vertical Centrifugal Pumps
5. Pumps can be operated in series or parallel according to the requirements of flow rate and head.
6. Vertical and horizontal installation of pumps can be adopted according to the requirements of pipeline layout.
Working conditions of vertical centrifugal pump:
1. The suction pressure is ≤ 1.0MPa, or the maximum working pressure of the pump system is ≤ 1.6MPa, that is, the pump suction inlet pressure+pump head is ≤ 1.6MPa. The static pressure test pressure of the pump is 2.5MPa. Please specify the system working pressure when ordering. When the working pressure of the pump system is greater than 1.6MPa, it should be separately stated when ordering, so that the overcurrent and connection parts of the pump can be made of cast steel materials during manufacturing.
2. Environmental temperature<40 ℃, relative humidity<95%.
Working principle of vertical centrifugal pump:
By relying on the action of the rotating impeller on the liquid, the mechanical energy of the prime mover is transmitted to the liquid. Due to the action of the centrifugal pump, as the liquid flows from the inlet to the outlet of the impeller, its velocity and pressure energy increase. The liquid discharged by the impeller passes through the extrusion chamber,
Most of the speed can be converted into pressure energy and then transported out along the discharge pipeline. At this time, a vacuum or low pressure is formed at the inlet of the impeller due to the discharge of liquid. The liquid in the suction tank is pressed into the inlet of the impeller under the action of liquid surface pressure/atmospheric pressure,
The rotating impeller continuously sucks in and discharges liquid.
What is a vertical centrifugal pump?
Vertical centrifugal pump
Key points for selecting vertical centrifugal pumps:
Reasonable pump selection requires comprehensive consideration of technical and economic indicators such as pump unit, pump station investment, and operating costs, in order to comply with the principles of economy, safety, and applicability. Specifically, it includes the following aspects:
1) High efficiency, low-noise, and energy-saving water pumps should be selected, and it is strictly prohibited to choose obsolete products.
2) The pump should be selected based on the design flow rate and required head, taking into account the decrease in pump output caused by wear and tear. The pump can be selected by multiplying the calculated head H by a coefficient of 1.05-1.10; A pump with a characteristic curve that gradually decreases in head as the flow rate increases should be selected. Such a pump works stably and is reliable when working in parallel; And the operating point of the water pump should be kept within the high-efficiency range, which not only saves energy but also prevents damage to the components.
3) When there are no regulating facilities in the water supply network, it is advisable to use speed regulating pump sets or rated speed pump sets to operate the water supply. The maximum water output of the pump unit should not be less than the design flow rate of the community's water supply, and should be verified based on fire protection conditions.
4) When selecting lifting pumps for water tanks and towers, the number of pumps should be minimized as much as possible, and one should be used and the other should be backup; When a single pump can meet the requirements, it is not advisable to use multiple parallel pumps; If it is necessary to use multiple parallel operation or combination of large and small pumps, the number of models should not be too many, and the number of models should generally not exceed two. The head range of the water pump should be similar; When running in parallel, each pump should still operate within the high-efficiency range.