A screw pump is a mechanical device designed to move fluid by using the principle of the rotating screw or helical impeller. It consists of the rotor inside a tube-like chamber and the screw pump transfers the liquid or semi-liquids from the inlet and to the outlet, regularly flowing without pulses. It is used in a factory due to its dependable performance, low maintenance, and flexibility in dealing with liquids of varying thickness.
What is a screw pump
A screw pump commonly known as a water screw, is a positive displacement pump that utilizes one or additional screws to travel fluid solids or liquids along the screw axis. Understand this way, a single screw spins in a cylindrical Concavity, traveling the material along the screw’s spindle.
This classic model is still utilized in many low-tech applications, like irrigation systems and farm machinery utilized to transport grain and other solids. The development of the screw pump has guided a variety of multi-axis technologies in which attentively crafted screws move in opposite locations or remain stationary in a cavity. The cavity can be profiled, generating cavities in which the conveyed material is (locked).
In external and marine arrangements, a three-spindle screw pump is widely utilized to pump viscous fluid under overhead pressure. Three screws thrust the pumped liquid into a closed chamber. The screws rotate in opposite locations, and the pumped liquid proceeds along the spindles of the screw.
Three-spindle screw pumps are utilized to transport viscous liquids with lubricating characteristics. They are appropriate for different applications like fuel hydraulic, fuel, lubrication, circulation, delivery, injection, oil burner, and supercharging.
Positive displacement pumps have several benefits over centrifugal pumps. The pumped fluid axial motion without turbulence, prevents foaming that would otherwise manifest in viscous liquids. Higher-viscosity liquids can be pumped without a decrease in flow rate. Modifications in the pressure difference also have hardly any effect on positive displacement pumps compared to centrifugal pumps.
Types of screw pumps
Different types of screw pumps are designed and available in the marketplace but we have discussed some common pumps. They are succinctly outlined below:
Single Screw Pump (Archimedes Screw):
These pumps are called “PC” pumps otherwise progressive cavity pumps or worm Pumps. These types of pumps are not regarded within the family of the screw pump. The rotor in these pumps is not such as a usual screw but moderately a twisted round shaft.
A progressive cavity pump includes one shaft partially twisted in the form of a screw and is enclosed within a pumping hall that is broadly rubber lined.
Twin Screw Pump:
These pumps are also called the double screw pump, and it is the most general type utilized for high-power applications like weighty oil tube move. The screws in the pumps are driven from the motor, and timing gears are commonly included to turn the subsequent screw.
Triple Screw Pump:
These pumps are also called triple screw pumps, and these are commonly utilized in small applications like lubrication systems. The screws in the pump are resolute from the motor to move the remaining two screws which are around it devoid of using timing gears.
Four Screw Pump:
These pumps are two screw pumps, nevertheless with two screws for each rotor in opposite locations. These pumps collect the liquid within the suction port, then divide evenly and are routed to both pumps’ ends.
The two liquids flow with the assist of the pump in the direction of the center and connect jointly again before leaving the release port. Alike to the double screw pump, this pump incorporates a timing mechanism to make the second rotor run. These pumps are frequently utilized within multi-phase applications and oil transport pipelines.
Five Screw Pump:
These pumps are mostly the same as a triple screw pump; nevertheless, with five screws, not three screws. Same to the 3-screw pump, this pump encompasses one diving rotor that drives all the remaining screws. This category of a pump is frequently utilized in many applications such a tube oil otherwise hydraulic.
Helical rotor screw pump:
These pumps are featured a helical rotor that move with a cylindrical stator and effective for handling high viscosity fluid.
Multi screw pumps:
These pumps are with more than two screw and offering increased capacity or efficiency.
Screw pump working principle
The screw pumps operate utilizing two counter-rotating screw rotors substitute are engineered so that they rotate “in the direction of each other”. This traps the gas in the gap between the screws of their rotors. As the screws move, this trapped volume reduces substitute not only compresses the gas but moves it in the direction of the exhaust.
In the first case, mechanical bearings uphold the rotors at both ends. The cantilever conceptualized solution supports the rotors at the high-pressure end and the rotors can be cooled within. A motor drives the two rotors through a gear.
The gear and the bearings are lubricated but attached from the pumping mechanism vacuum generator through shaft seals or labyrinth seals, The rotors have no mechanical connection between each other and the pump housing, yielding zero mechanical wear.
To keep the set-up electrical power low, modern pumps are driven by an electronic frequency change and rotate slower at pressure ranges near atmospheric pressure. Several versions utilized so-called blow-off valves instead to keep the moving speed constant also at high pressures. Cooling is normally done with water.
Parts of screw pumps
A screw pump is a types of positive displacement pump that moves the fluid using one or more screw and helical rotors.
Screw or rotors: The acrew or rotors are primary moving components of the screw pumps.
Inlet and outlet portal: The inlet portal is where the fluid inters the pumps and the outlet portal is where the pump fluid discharged.
Seals and bearing: Seals and bearing used to stop the leak of the fluid with the rotating screw and between different sections of the pump.
Control mechanism: Screw pumps may joint different controlmechanism to regulation of flow rate and pressure.
Drive mechanism: The pump required drive mechanism due to roate the screw.
Casing: The casing provide a confident space for the fluid to move via.
Screw pump parts and diagram
- A-Discharging body
- B-Pull bar
- C-stator
- D-Screw shaft
- E-Gimbal
- F-Pump body
- G-Connect shaft
- H-stuffing box
- I-Gland fange
- J-Bearing seal
- K-Bearing
- L-Transmission shaft
- M-Bearing cover
- N-Coupling
- O-Base plate
- P-Motor
Application of screw pumps
Three-spindle screw pumps are utilized for the post of viscous fluids with lubricating attributes. They are appropriate for a variety of applications like fuel injection, fuel, lubrication, circulating, feed, oil burners, boosting, and hydraulics.
- Some of the examples of these pumps utilized in systems incorporate Multi-phase Pumping, Weighty Oil pipelines, Lubrication, and Hydraulic Systems.
- common pump applications are high-viscosity fluids such as asphalt, oil, and multi-stage liquid, which means there is fluid and steam mixed connected within the liquid stream.
- These pumps have many utilized in a variety of applications in factories like oil, manufacturing, gas, and mining.
- These pumps are used for for transferring crude oil from storage tanks to refining units or for pipeline transportation.
Performance of screw pumps
Screw pumps can reach Supreme pressures of ~ 1e-3 mbar. The operating pressure range is 103 to 10-2 mbar. Different sizes with pumping speeds of ~ 60 – 1200 m³/h are accessible. The pumping speed in the vacuum range < 10 – 50 mbar can be Improved by placing a roots blower on top. These mixtures, regularly in one single pump housing, are ready up to 9000 m³/h.
Screw pump symbol
The screw pump symbol is like a special drawing that shows the main thing how to move fluid. For example, A two screws inside a round or half round house that symbol looks like. This symbol represents a kind of pump that is good at moving fluid in a dependable way.
People are used the screw pump symbol a lot in different places like ship and oil and gas industries. The twisty shape in the symbol shows how the pump works by turning around.
It helps them to understand and talk about planning and drawing simply. the screw pump symbol is also like a picture that speaks a story about how many peoples are really using the simple idea to make things work well.
Difference between gear pump and screw pump
Here are the key differences between gear pumps and screw pumps:
Nurber of Screw or Gear:
Screw pump: These pumps basically have one or more helical screw that rotate to moves the fluids. Single row and the double screw pumps are commonly types of screw pump.
Gear pump: Gear pump basically have two or more gear that creating the pumping action together.
Sealing:
Screw pump: These pump generally have good inherent sealing capabilities because of helical geometry of the screw.
Gear pump: These pump often need tight tolerance between the gears and casing due to prevent fluid from leaking back into the pump.
Operations:
Screw pump: The screw pumps, on the other head operate helical screw and screw that move fluid with the screw axis.
Gear pump: Gear pump operate based on the principle of the meshing gears. They basically consist of two or more gears that moves in near proximity whithin the casing.
Flow characteristics
Screw pump: These pump usually provide a more continuous and smooth flow.
Gear pump: The gear pump tend to offer a more pulsating flow, which many needs extra meassures to smooth out the flow.
Advantage of of screw pumps
Some screw pumps benefit are includes:
- Freely and quiet operation
- Reduction of mechanical vibration
- zero pulsation
- Adaptability flow rate
- Adjustable output
- Self priming attributes
- Robust tolerance for air or gas
- Low internal velocities
- Hight suction capacity
- Cost effective
- Compact design
- Ease of maintenance
- Long seal life
- Temperature tolerance
- Low NPSH requirement
Disadvantages of of screw pumps
The disadvantages are includes:
- Risk of cavitation
- sensitive to particles contaminations
- Manufacture cost high
- Down volumetric and mechanical efficiencies
- Sensitive to viscosity changes of the fluid
- They are massive and heavy
FAQs
What is screw pump?
Answer: A screw pump commonly known as a water screw, is a positive displacement pump that utilizes one or additional screws to travel fluid solids or liquids along the screw axis.
How does screw pump works?
Answer: The screw pumps work by turning a twisted screw gently push liquids via a tight space, making sure the fluid flow smooth and constant.
What type of pump is a screw pump?
Answer: Screw pumps is a types of pump that moves liquid using a twisting screw mechanism.
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Conclusion
We hope that we have cleared all yours questions about screw pump. If you have any queries about the “SCREW PUMPS” you can contact directly in my contact us page. Thanks for reading.
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