Screw Pump Types and Applications

The screw pump structure is similar to a screw, and the owl spindle construction is similar to an Archimedes screw. The spindle of the pump is responsible for the action of the pump. Over the years, this pump has observed. This pump is a potential device intended for raising the pump pressure. The maintenance of this pump is less. Like other pumps, these pumps are also taking the mechanical from a motor. The different parts in these pumps can be made with different materials like casing is made with cast iron, screw shafts are made with high-grade carbon steel, and bearing is made with high-speed steels. This article discusses an overview of the screw pump.

What is a Screw Pump?

This is a positive displacement pump which can be built with several screws. These screws are intermeshed to pressure liquids & move them within a system. The screws in the pump take the fluids and push out from another surface while growing its pressure.

The construction of this pump is consistent as well as simple in making. It has three screws spindles where one screw is drivers and remaining two screws are driven. These screws have a good clearance among them and it is responsible for the fluid pumping action. The liquid supply to the screw is given throughout the motor.

These pumps have a casing with inlet as well as an outlet, where the inlet is always selected at the bottom of the pump and outlet is selected at the upper side of the pump. All these can be observed in construction. It has a relief valve mounted at the outlet end.

Screw Pump Working Principle

The working of the screw pump is when this pump is pushing thick fluid, and then the screws can be connected strongly with no permission, as the faces are being lubricated like the liquid is pumped. When the fluid is pumping, then these parts cannot get in touch with each other, also fast wear on the elements will take place. Due to this reason, a three screw pump should not be utilized for multi-phase or water service.

In triple screw pumps, only shaft seals are required over the rotor driving. Additional rotors include bearings, which are covered within the pumping hall. In a 2-screw pump otherwise a 4-screw pump, generally, rotors protrude throughout the pump container into a gear container wherever the timing gears are enclosed. Because of this reason, 4-shaft seals are mandatory within a screw pump through two rotors.

Screw Pumps Types

There different types of screw pumps are available in the market in different designs. They are briefly discussed below.

One-Screw Pump

These pumps are named as PC pumps otherwise progressive cavity pumps, and worm Pumps. Generally, these types of pumps are not considered within the family of the screw-pump. Because the rotor in these pumps are not like a usual screw but somewhat a twisted round shaft. A progressive cavity pump includes one shaft with somewhat twisted within the form of a screw, & is enclosed within a pumping hall that is generally rubber lined.

Two Screw Pump

These pumps are also named as the double screw pump, and it is the most general type used high power applications like weighty oil tube transfer. The screws in the pumps are driven from the motor, & timing gears are generally included to turn the next screw.

Three Screw Pump

These pumps are also named as the triple screw pumps, and these are usually used in small applications like lubrication systems. The screws in the pump are determined from the motor to rotate the remaining two screws which are around it without using timing gears.

Four Screw Pump

These pumps are basically two screw pumps, however with two screws for each rotor in opposite directions. These pumps absorb the liquid within the suction port, then divides evenly & is routed to both pumps ends.

The two liquids flow with the help of the pump towards the center & connect jointly again before leaving the release port. Similar to the double screw pump, this pump includes a timing mechanism to make the second rotor run. These pumps are frequently used within Multi-phase applications & oil transport pipelines.

Five-Screw Pump

These pumps are mostly similar like a triple screw pump; however with five screws, not three screws. Similar to the 3 screw pump, this pump includes one diving rotor that drives all the remaining screws. This type of pump is frequently used in many applications like tube oil otherwise hydraulic.

Advantages and Disadvantages

The advantages and disadvantages of screw-pumps include the following.

• These pumps provide the maximum flow speed of PD pumps.
• So these pumps are the best choice for the people who work with hard liquids which are not movable & require for shifting them quickly like oil, gas and other high thickness liquids.
• These pumps are a good choice for 2-phase fluid as well as gas mixtures. But with the exemption of only pumps, these are not suitable for shifting dirt free liquids at stable rates. Additionally, the difficulty of these pumps frequently comes with amplified protection and small gear as contrasted to more easy pumps.

Screw Pumps Applications

The applications of screw pumps include the following.

• These pumps have many uses in a variety of applications in industries like oil, manufacturing, gas, and mining.
• Most of the pump applications are high viscosity fluids like asphalt, otherwise oil, multi-stage liquid, which means there is fluid and steam mixed jointly within the liquid stream.
• Some of the examples of these pumps used in systems include Multi-phase Pumping, Lubrication, Hydraulic Systems, and Weighty Oil Pipeline.

Thus, this is all about screw pumps uses, sometimes these pumps are selected based on single suction otherwise double suction. The two screw pumps design is single suction where the liquid enters from one side and exits from another side. Similarly, four screw pumps design is double suction which includes the suction stream that divides into both ends and flows through an exit in the middle. Here is a question for you, what are the problems occurred while operating these pumps?