Introduction. The operating manual of any centrifugal pump often starts with a general statement,. “Your centrifugal pump will give you completely trouble free. This tutorial is intended for anyone that has an interest in centrifugal pumps. How to verify that your centrifugal pump is providing the rated pressure or head?. ❖Basic Angular Momentum Considerations. ❖The Centrifugal Pump. ❖ Dimensionless Parameters and Similarity Laws. ❖Axial-Flow and Mixed-Flow Pumps.
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Centrifugal Pump: A mechanical device used to transport fluids by the conversion . Retrieved October 22, , from ronaldweinland.info 'The Centrifugal Pump' is primarily meant as an inter- nal book and is aimed at technicians who work with development and construction of pump components. Centrifugal Pump can be defined as a mechanical device used to transfer liquid of various types. • As the name suggests, it relies on the principal of Centrifugal.
Ramaiah Institute of Technology, Bangalore A pump is a hydraulic machine which converts mechanical energy into hydraulic energy or pressure energy. A centrifugal pump is also known as a Rotodynamic pump or dynamic pressure pump. It works on the principle of centrifugal force. In this type of pump the liquid is subjected to whirling motion by the rotating impeller which is made of a number of backward curved vanes. The liquid enters this impeller at its center or the eye and gets discharged into the casing enclosing the outer edge of the impeller.
Delivery pipe is a pipe connected to the pump to the overhead tank. Delivery valve is a valve which can regulate the flow of liquid from the pump. Priming of a centrifugal pump Priming is the process of filling the suction pipe, casing of the pump and the delivery pipe upto the delivery valve with the liquid to be pumped.
If priming is not done the pump cannot deliver the liquid due to the fact that the head generated by the Impeller will be in terms of meters of air which will be very small because specific weight of air is very much smaller than that of water.
Heads on a centrifugal pump: Suction head hs : it is the vertical distance between the liquid level in the sump and the centre line of the pump. It is expressed as meters. Delivery head hd : It is the vertical distance between the centre line of the pump and the liquid level in the overhead tank or the supply point. It is expressed in meters. Working operation of a centrifugal pump is explained in the following steps.
Therefore impeller increases the energy of the liquid and delivers it to the reservoir. It may be noted that a uniform velocity of flow is maintained in the delivery pipe. This is due to the special design of the casing. As the flow proceeds from the tongue of the casing to the delivery pipe, the area of the casing increases.
There is a corresponding change in the quantity of the liquid from the impeller. Thus a uniform flow occurs in the delivery pipe. Operation difficulties in centrifugal pumps a Pump fails to pump the fluid. A centrifugal pump running at Rpm is working against a total head of A centrifugal pump impeller having external and internal diameter mm and mm respectively is running at Rpm.
The rate of flow through the pump is 0. If the power required to drive the pump is It is required to deliver 0. Find the power required to drive the pump.
The impeller of a centrifugal pump is of mm diameter and 50mm width at the periphery and has blades whose tip angle incline backwards 60 from the radius. Assuming that the pump is design to admit radically. The following data relate to a centrifugal pump. Find the pressure rise in the impeller.
A centrifugal pump delivers water at the rate of lpm,to a height of 20m, Through a 0. A centrifugal pump is required to deliver ltrs of water per second against a head of 16m, when running at rpm.
Find the power required to drive the pump and what pressures will be indicated by the gauges mounted on the suction and delivery sides. Following data were obtained from a centrifugal pump in a laboratory.
Find the efficiency of the pump.
The internal and external diameters of the impeller of a centrifugal pump are 40cms and 80cms respectively. The pump is running at rpm. The vane angles at inlet and outlet are and respectively. Water enters the impeller radially and velocity of flow is constant. Determine the workdone by the impeller per kN of water.
The impeller of a centrifugal pump runs at 90 Rpm and has vaves inclined at to the direction of motion at exit. Take the velocity of flow as 2. A centrifugal pump delivers lps against a head of 20m. When the impeller rotates at rpm. The diameter of the impeller a The blade angle at exit Take the width of the impeller at exit as 0.
A centrifugal pump lifts water against a static head of 40m. The section and delivery pipes are each 15cm in diameter. The head loss in the section and delivery pipes are respectively 2. The impeller is 40cm in diameter and 2. It revolves at Rpm and the vane angle at exit is Calculate the discharge. A centrifugal pump has a total lift of 15m and is placed 2m above the water level in the sump.
Neglect friction and other losses. The axis of a centrifugal pump is 2. The friction losses in the section and delivery Pipes are of 15cm diameter.
The impeller is 30cm diameter and 2cm wide at outlet and its speed is Rpm. The blade angle at exit is If the guages are 15 connected to the section and delivery sides of the pump determine the pressure indicated by these guages.
If the Quantity of slurry to be pumped is lps against a head of 15m. Find also the pressure developed by the pump. Determine the manometric and overall efficiencies of a centrifugal pump from the following data. When a centrifugal pump is started , Will start delivering liquid only if the pressure rise in the impeller is more than or equal to the manometric head H mano. The impeller of a centrifugal pump is 1.
If the blades are curved backward and the outlet angle is 30 calculate the manometric efficiency and the power required to run the pump. Estimate the minimum speed to start the pump if the impeller diameter at inlet is 0. The diameters of the impeller of a centrifugal pump at inlet and outlet are 40cm and 80cm respectively. Determine the minimum starting Speed if it works against a head of 25m.
The important functions of a multistage centrifugal pump are; i To produce high head pumps in series ii To deliver or discharge large quantities of a liquid pumps in parallel Pumps in parallel: it is an arrangement made by mounting a number of impellers on the shaft of a motor as shown.
Such an arrangement is useful when the liquid has to be pumped to large heights keeping the discharge constant. Pumps in parallel: it is an arrangement made by connecting a number of pumps in parallel as shown. Such an arrangement is useful when a large quantity of liquid is to be pumped to a particular height. Problems: 1. A three stage centrifugal pump has an impeller of 40cm diameter and 2. Find the number of impellers and the diameter of each impeller required for a multistage centrifugal pump to lift 80lps of water against a total head of m.
It is denoted by Ns. Specific speed is a characterstic of pumps which can be used as a basis for comparing the performance of different pumps. Calculate the specific speed of a centrifugal pump running at Rpm.
The diameter of the impeller is 30 cm and its width 6cm. The effective outlet blade angle is In order to predict the behaviour of the pump under varying conditions of speed, discharge and head, full scale tests are usually performed. The results of these tests are plotted in the form of characteristic curves. These curves are very useful for predicting the performance of pumps under different conditions of speed, discharge and head.
Following four types of characteristic curves are usually prepared for a centrifugal pump. Main characteristic. Operating characteristics c. Constant efficiency or Muschel characteristic. Constant head an constant discharge curves. Main Characteristic: the pump is operated a particular constant speed, discharge is varied by adjusting the delivery valve.
Manometric head Hm and the shaft power P are measured for each discharge. The overall efficiency is then calculated.
A set of similar curves are plotted by running the pump at different speeds. They will be as shown. Operating characteristic: The curves are obtained by running the pump at the design speed, which is also the driving speed of the motor.
The design discharge and head are obtained from the corresponding Curves, where the efficiency is maximum as shown. Constant efficiency curves: The constant efficiency curves are obtained from the main characteristic curves. The line of maximum efficiency is obtained by joining the points of the maximum curvature of the constant efficiency lines. These curves are useful in Determining the range of operation of a pump. Constant head and constant discharge curves: If the pump has a variable speed, the plots between Q and N and that between Hm and N may be obtained by varying the speed.
If it delivers 0. Calculate the speed and the head of the prototype assuming the same efficiency, what is the specific speed of the pump if the discharge in the prototype is 0. Two geometrically similar pumps are running at the same speed of Rpm. One pump has an impeller diameter of mm and lifts water at the rate of 0. Determine the head and impeller diameter of the other pump to deliver half the discharge.
The cavitation in a pump can be noted by a sudden drop in efficiency head and power requirement. The harmful effects of cavtation are: a Pitting and erosion of surfaceSudden drop in head, efficiency and power delivered to the fluid.
The factors which facilitate outlet of Cavtation are as follows: a Restricted section b High runner speed b Too high specific speed for optimum design parameters c Too high temperature of the following liquid. Explain with neat sketch the working of single stage centrifugal pump. Find the power required to drive centrifugal pump which delivers 0. A centrifugal pump discharges 0. Explain breifly i Single and multistage pumps ii Priming of pumps iii Manometric head iv Efficiencies of centrifugal Aug 24 v 5.
What is priming in centrifugal pump? Newtonian fluids. At the end of the day, the pump packaging must be loaded with fluid before the pump is begun, or the pump won't have the capacity to Fig.
On the off chance that the pump packaging winds up noticeably loaded with vapors or gasses, the pump impeller progresses toward becoming gas-bound and unequipped for pumping. Solid works mechanical design automation software is a feature-based, parametric solid modeling design tool which advantage of the easy to learn windows graphical user interface . Parameters allude to imperatives whose esteems decide the shape or geometry of the model or gathering .
Parameters can be either numeric parameters, for example, line lengths or circle distances across, or geometric parameters, for example, digression, parallel, concentric, level or vertical, and so forth. Outline plan in auto cad software and imported to solid work design is the means by which the maker of the part needs it to react software for further analysis. CFD analysis is carried out on to changes and updates . A few variables add to how we fluids like Olive oil and slurry.
Initially the pressure of catch plan goal are Automatic relations, Equations, included Modeling of a Centrifugal Pump Initially the model is drawn in 2-D by using different commands in Auto cad software and the isometric view of centrifugal pump as shown in the figure 1.
All rights reserved by www. As the pressure increases with respect to the length the flow rate of the olive oil is Maximum. The velocity increases with respect to the length the flow rate of the fluid also increases.