Screw pumps and it different designs

in this presentation the different varieties of screw pump is shown with proper applications

1. DEPARTMENT OF MECHANICAL ENGINEERING TAE-II (TECHNICAL PRESENTATION) Name of Subject:- Fluid Power- II Name of the Topic :- Screw Pumps, different designs Name of Student:- Digvijay T. Singh Roll No.:- 53 Semester:- 4 th Section:-D Name of Faculty:- Mr. Yogesh Nandanwar Session: 2015-16

2. Introduction : Screw pumps are classified as positive, constant-displacement rotary pumps. The one screw pump is called as progressive cavity pump. By far, the largest applications of screw pumps are of the three-screw kind. This pump consist esentially of three intermeshing helical thread screws housed inside a chamber with an inlet and outlet .

3. Types of Screw Pumps : One screw pump Two screw pump Three screw pump Exploded View of a Screw Pump :

4. Working of Screw Pump : The pumping liquid from the inlet is trapped between the teeth of the idler screws. Though continuous, the flow can be considered as a series of packets lying between a set of two adjacent threads of the idler. The rotation of the driver causes each packet of trapped liquid to move progressively forward in the axial direction and ultimately to the outlet. For each turn of the driver, the displacement is a constant quantity. Continuous rotation causes a continuous stream of liquid to be pushed out of the exit as a constant stream of liquid. The flow rate is a function of the speed of rotation and also depends as the cube of the diameter of the power rotor. The speed is relatively low.

5. Different Designs of Screw Pumps :

6. Advantages of screw pump : It has a good efficiency of about 80-85% which depend upon the viscosity of the liquid and the pressure head of the pump. It has a flow range of 10 to 1500 litres /minute. It has a speed of 750 to 3500 rpm. It has high suction capability. It run very quietly and reliable and robust. The pump is self-priming.

7. Applications : Screw pumps find considerable applications in machinery lubrication, fuel-oil transport . powering of hydraulic machinery, conveyance of high temperature and viscous fluid like asphalt and residual oils in refinery. They find extensive use in ships, commercial vessels and barges to handle lubricating oils and hydraulic fluids.