Working Principle of Screw Pump
Screw pumps are positive displacement pumps, which use mechanical means to increase the pressure of a fluid while transporting the fluid from one place to another. They are commonly used to deliver liquid or gas in a range of applications, including aviation, automotive, and industrial production. Generally speaking, these pumps are powered by a prime mover, such as an electric motor, and operate by turning a pair of synchronised screws that are suspended in a housing or casing.
At a very basic level, the working principle of a screw pump involves creating a series of small convolution that are designed to move liquids or gases in one direction from the inlet to the outlet in a dependable and continuous manner. When the driven screws are turned, they move the fluid in the path of their rotation, filling the space between them until it reaches the outlet.
The rotating screws cause a partial vacuum in the working chamber, which causes or suctions the medium to flow into the screw pump. As the drive mechanism rotates the screws, the medium is conducted downwards, redirected within the pump and then pushed out of it through the outlet.
The screw pumps feature a pair of lobed, intermeshing screws, while the number of lobes and the pitch of the screw are carefully calculated to ensure the necessary flow rate and pressure. In addition to this, the internal clearance between the screws, shafts, and their retaining mechanisms must be accurately set according to the type of the material they are transporting and the viscosity of the liquid.
Screw pumps are widely used due to their many advantages. They are best suited for applications that require high precision, high pressure and demand a large fluid transfer rate. They provide an excellent suction lift performance, high volumetric efficiency, handles both lubricating and non-lubricating fluids as well as capable of reversing and self-priming very easily.
The screw pumps have a number of advantages over other types of pumps for handling fluids. They provide a much higher volumetric efficiency than the other types, resulting in greater flow rates over a given size. They also have less radial limitation on inlet and outlet pressure and power consumption, which can result in longer life and lesser maintenance. In addition to this, they require less space to operate, compared to other pumps.
Screw pumps are also relatively simple and robust in design, which makes them highly reliable and able to operate in difficult environments. They are resistant to wear and abrasion and require little to no maintenance, reducing the total cost of ownership. The tightly specified tolerances of the parts makes the pumps resistant to vibration and pulsation.
In conclusion, the screw pump is a simple and reliable device with a wide range of applications. It provides precise speed, efficient performance and precise control of pressure and flow rate. Although its initial setup costs may be high, its low maintenance requirements and long life span make it a cost-effective solution for many industries.
