A pump is a mechanical device that transports a medium by converting the energy provided by an electric motor into hydraulic energy. It transmits the mechanical energy of the prime mover or other external energy to the liquid to increase the liquid energy. Pumps are mainly used to transport water, oil, acid and alkali liquids, emulsions, suspensions and liquid metals and other liquids, but also liquid, gas mixtures and liquids containing suspended solids. Therefore, the premise of choosing the right pump is to consider the characteristics of the transport medium, followed by the fluid, flow rate, operating temperature, vapor pressure and other factors. How to choose a right pump?
Identifying the media that will be transferred is the first step in preventing corrosion occurrences and, consequently, early pump wear. Therefore, it is crucial to understand the viscosity, chemical makeup, and potential existence of solid components of the media to be pumped. Having a complete understanding of all the physical characteristics of the treated fluid will help you select the best technology for your needs and building materials that work with the pumped media. Before selecting the pump's housing, refer to chemical compatibility lists. Next, you ought to examine the features associated with media transportation, including fluid, flow rate, operating temperature, vapor pressure, suction head, working environment.
Fluid: Pumps not designed for the job can be destroyed by chemicals and fuels. Select a pump that is made to withstand the fluid's corrosiveness and consistency to prevent slurry or debris from causing it to deteriorate or clog. In a similar vein, ascertain the fluid's viscosity to make sure the pump has sufficient force to pull the liquid through.
Flow Rate: Multiply the entire volume by the amount of time you wish to transfer the liquid to determine the desired flow rate. The needed flow rate of pumps typically expressed in cubic meters hour(m³/h) or gallons per minute (GPM), the flow will inevitably affect the pump’s and dimensions. For example, you would want to choose a pump with a minimum rated flow rate of 500 GPH (gallon per hour) for a 500-gallon pond that needs full circulation once an hour.
Operating Temperature: Although pumps have a wide temperature range of operation, make sure the pump is rated for the highest temperature of the liquid you will be pushing if you are working with liquids that are hotter than 200°F.
Vapor Pressure: The force per unit area that a fluid produces when transitioning from a liquid to a vapor is known as vapor pressure. If your fluid has a high vapor pressure, make sure the pump is rated for it to reduce the chance of cavitation.
Suction Head: This means height between the inlet of the suction pipe and the pump. Generally speaking, the suction head shouldn’t be higher than ten meters. Beyond this, you must be taken into consideration of submersible pump.
Working Environment: If the pump will be installed outside, it is best to consider to special construction or installation for sever cold weather. When you want to put your pump into a hazardous environment, containing explosive vapors or dusts, we can help you to equip it with a special motor.
The medium to be pumped plays a very important role in the selection of the right pump, because the pump's properties are determined by the fluid's viscosity, its suction temperature, and the presence or absence of solid particles. You need to ensure if the media to be conveyed belongs to chemically neutral or corrosive, which means help you choose the pump designed to operate under these conditions.
In general, the higher the viscosity of the medium, the more difficult it is to flow through the pumping system, but it should be noted that the viscosity of the medium will vary depending on the operating conditions. There are 4 main groups of fluids according to their viscosity level.
First Group: Fluids move in the same way regardless of the speed or degree of agitation, for example, water, alcohol, oil, etc. For these applications, you are not too restricted in your choice of pumps.
Second Group: The viscosity of the medium will increase with the mixing speed, such as butter, cream and some other foodstuffs.In these cases, standard centrifugal pumps will not be suitable for fluid flow.
Third Group: Media that must first surpass a threshold in order to flow, the viscosity reduces with agitation after this stage is reached.
Fourth Group: They are very viscous at rest, but their viscosity decreases with continuous mixing, such as paints, greases, and adhesives.
Centrifugal pumps are generally the best option for low viscosity fluids (the first and second group), as the pumping action produces a high shear rate of the fluid. However, as the viscosity increases, you will need to account for the additional resistance that the fluid will exert on the shear rate. Conversely, because positive-displacement pumps work at lower speeds and transfer less shear energy to the fluids than centrifugal pumps do, they are the ideal option for viscous fluids (those in the third and fourth groups). When is a centrifugal pump the best choice？
Centrifugal pumps suck in fluid to deliver large quantities of fluid by drawing in fluid with one or more impellers (e.g., impellers or propellers), which can deliver a continuous flow of a huge volume of fluid at a fast speed. It is one of the most often used pump mechanisms and can be used to pump media that may contain solid components and has a low viscosity.
The centrifugal pumps is a kind of strong equipment with high efficiency. This kind of pump has a steady flow rate and can pump big amounts. The centrifugal pump can often used to supply a wastewater treatment facility, or pump thick fluids or cleaning fluids, such as mining, agriculture, water, manufacturing, power generation and petroleum. When should you use a gear pump?
Gear pump can be used to transport viscous liquids without solid particles under high pressure. Therefore, this machine is applicable for conveying highly viscous materials at high temperatures and can even reverse the direction in which they pump.
The gear pump has the features of constant flow, very little noise during the operation. At the same time, the machine is not very expensive to maintain due to its durable materials, simple design, compactness and reliability. However, when you have a high-flow work scenario, gear pumps are not the best choice. They are also frequently used in the foundry industry, in automatic presses, and in plastics processing.
When you have more usage scenarios and don't know how to choose, there are a professional staff to recommend the most suitable pump or customise a pump solution for you. Shenghui Pump Company is a professional manufacturer and supplier, which has been established for more than 10 years and has been focusing on the production and research and development of pump machines. So far, our company has produced nearly 4200 types of pumps, mainly producing external gear pumps, internal gear pumps, cam pumps, centrifugal pumps, screw pumps, multi-stage pumps, chemical pumps, vacuum pumps and other series of pumps. Due to our strict control of product quality and excellent after-sales service, our products enjoy a good reputation in the global market and we have established long-term good relations with some first-class companies.
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