1.3 Screw Pump

By -
Definition:-

         A screw pump is a positive-displacement (PD) pumps that use one or several screws to move fluids or solids along the screw(s) axis. In its simplest form (the Archimedes' screw pump), a single screw rotates in a cylindrical cavity, thereby moving the material along the screw's spindle.

Detail:-
Screw pumps (fixed displacement) consist of two Archimedes' screws that inter mesh and are enclosed within the same chamber. These pumps are used for high flows at relatively low pressure (max 100 bars (10,000 kPa). They were used on board ships where a constant pressure hydraulic system extended through the whole ship, especially to control ball valves,but also to help drive the steering gear and other systems. The advantage of the screw pumps is the low sound level of these pumps; however, the efficiency is not high.



The major problem of screw pumps is that the hydraulic reaction force is transmitted in a direction that's axially opposed to the direction of the flow.
There are two ways to overcome this problem:

Put a thrust bearing beneath each rotor;
Create a hydraulic balance by directing a hydraulic force to a piston under the rotor.


written by:-Farhan Mustafa,
E_mail:- farhanmustafa522@gmail.com

Comments

Post a Comment

Popular posts from this blog

Physical properties of Liquid

By -
Image
(1) Additive Property When a property of a substance is equal to the sum of the Corresponding properties of the constituent atoms, it is called an additive property . For example, molecular mass of a compound is given by the sum of the atomic masses of the constituent atoms. (2) Constitutive Property A property that depends on the arrangement of atoms and bond structure, in a molecule, is referred to as a constitutive property . Surface tension and viscosity and optical activity are examples of constitutive property. (3) Additive and Constitutive Property An additive property which also depends on the intermolecular structure is called additive and constitutive property. Surface tension and viscosity are such properties. (4) COLLIGATIVE PROPERTIES Colligative Properties (Greek colligatus = Collected together). A colligative property may be defined as one which depends on the number of particles in solution and not in any way on the size or chemical nature of
Read more

Characteristics and Limitations of computer:

By -
Image
Ø SPEED: Computer is very fast calculating device It can execute basic operations like addition, multiplication, subtraction and division at a few microseconds. Ø ACCURACY: The accuracy of computer does not go down when they are used continuously for hours together. It always gives accurate results. Ø STORAGE: Computer has a very large storage capacity. It has an in-built memory where it can store a large amount of data. We can also store data in secondary storage devices like Floppy disk, Hard disk etc. Ø VERSATILITY: It means computer can perform different types of job efficiently. Computer can work with different types of data and information such as visuals, text, graphics & video etc. at same time. Ø PAPER WORK REDUCED: The computer reduces the paper work of any organization. The required data which was earlier stored in files, drawers and cabinets is now stored in the memory of computer. So Organization can reduce the paper work.  Ø MANP
Read more

1.4 Bent Axis Piston Pump

By -
Image
    Simple Definition:-               Hydraulic piston pumps can handle large flows at high hydraulic system pressures. Typical applications are mobile and construction equipment, marine auxiliary power, metal forming and stamping,machine tools and oil field equipment.      In these pumps, the pistons accurately slide back and forth inside the  cylinders that are part of the hydraulic pump. The sealing properties of the pistons are excellent.     Detail:-        In bent axis design, the displacement volume is dependent on the swivel angle: the pistons move within the cylinder bores when the shaft rotates. In swash plate design, the rotating pistons are supported by a swash plate; the angle of the swash plate determines the piston stroke. Bent axis pumps, axial piston pumps and motors using the bent axis principle, fixed or adjustable displacement, exists in two different basic designs. The Thoma-principle (engineer Hans Thoma, Germany, patent 1935) with max 25 degr
Read more