g.h.patel collage of engineering and technology Active learning assignment Subject- fluid flow operations Submitted by:- chavda Himalaya - 140110105006 Chudasama ankit - 140110105007 Faldu jatin - 140110105008 Gandhi achal - 140110105009 Haldaria parth - 140110105010

Topic :- pumps,valves and measuring devices INTRODUCTION:- WE HAVE MADE THIS POWER POINT PRESENTATION ON ABOVE TOPIC. PUMPS ARE THE EXTRAMELY USED DEVICES IN INDUSTRIES TO PASS THE FLUID MATERIALS FROM ONE PLACE TO ANOTHER IN VARIOUS HIGHT DIFFERENCES VALVE IS A BASIC NEED FOR FITTINGS AND A device for controlling the passage of fluid through a pipe or duct, especially an automatic device allowing movement in one direction only. OTHER MEASURING DEVICES ARE LIKE VENTURI METER,ORIFICE METER,ROTA METER,POSITIVE DISPLACEMENT METER ETC WE WILL DISCUSS VERY SOON.

PUMPS:- pump machine is a device for converting the energy held by mechanical energy into fluid. Pumps enable a liquid to:- 1. Flow from a region or low pressure to one of high pressure. 2. Flow from a low level to a higher level. 3. Flow at a faster rate.

Positive displacement There are two main categories of pump: Rotodynamic pumps. Positive displacement pumps. Diaphragm Piston Plunger Reciprocating Rotary Mixed flow Gear Lobe Sliding Vane Screw Axial flow Centrifugal Rotodynamic Turbine Positive displacement PUMP

Positive-displacement Pumps: Centrifugal Pumps: Centrifugal pumps have a rotating impeller, also known as a blade, that is immersed in the liquid. Liquid enters the pump near the axis of the impeller, and the rotating impeller sweeps the liquid out toward the ends of the impeller blades at high pressure. For low flows and high pressures, the action of the impeller is largely radial Positive-displacement Pumps: A variety of positive-displacement pumps are also available, generally consisting of a rotating member with a number of lobes that move in a close-fitting casing. The liquid is trapped in the spaces between the lobes and then discharged into a region of higher pressure. A common device of this type is the gear pump, which consists of a pair of meshing gears. The lobes in this case are the gear teeth

Construction of Centrifugal Pumps 1- Casing:- Volute Suction Impeller Casing generally are two types: I. Volute casings for a higher head. A volute is a curved funnel increasing in area to the discharge port. II. Circular casings for low head and high capacity. have stationary diffusion vanes surrounding the impeller periphery that convert velocity energy to pressure energy.

Axial flow Radial flow Mixed flow 2-Impeller Three main categories of centrifugal pumps exist Axial flow Radial flow Mixed flow

Positive displacement pumps:- A positive displacement pump makes a fluid move by trapping a fixed amount and forcing (displacing) that trapped volume into the discharge pipe. Some positive displacement pumps use an expanding cavity on the suction side and a decreasing cavity on the discharge side.

valves :- TYPES OF VALVES:- Gate Valve Globe Valve Plug Valve A valve is a device that regulates, directs or controls the flow of a fluid (gases, liquids, fluidized solids, or slurries) by opening, closing, or partially obstructing various passageways. Valves are technically fittings, but are usually discussed as a separate category. In an open valve, fluid flows in a direction from higher pressure to lower pressure. TYPES OF VALVES:- Gate Valve Globe Valve Plug Valve Check Valves 1) Swing Check Valve 2) Lift Check Valve 3)Ball Check Valve

The term gate as applied to valves refers to the type of valves in which the port is closed by a flat faced disc or gate sliding at right angle over the seat port to close it. In gate valve, the diameter of the opening through which the fluid passes , is nearly all the same as that of the pipe and direction of flow does not change. Gate valve work best when fully opened or fully closed. When the valve is partly opened , the disc is subjected to severe erosion and then the flow can no longer be stopped completely. Gate Valve:-

Globe Valve:- These valves are used for controlling the flow and have got many types of design like manually operated type, power actuated type etc. It contain a disc or a plug which moves to and fro from the seat. Thus stopping and allowing the flow through the valve body respectively. The pressure drop in globe valve is rather high because it has to move through two right angle turns. The shape of he plug and the seat depends upon the type of flow regulation desired. Their pressure and temperature limitations are up to 2200 psi and 1000 deg F respectively.

Check valves:- These valves are used where the prevention of flow reversal is desired. The valves are designed to perform this function automatically. The pressure of the liquid keeps the valve open in one direction only. It is closed either by the back pressure of the fluid or by the weight of the check system when the flow reverses. Main types of check valves are: Swing check valve Lift check valve Ball check valve

Other measuring devices:- 1) VENTURI METER 2) ORIFICE METER 3) ROTA METER 4)POSITIVE DISPLACEMENT METER

Venturi meter PRINCIPAL:- “BY REDUCING THE CROSS SECTIONAL AREA OF THE FLOW PASSAGE, A PRESSURE DIFFERENCE IS CREATED AND THE MEASUREMENT OF THE PRESSURE DIFFERENCE IS USED TO FIND THE FLOW RATE THROUGH THE PIPE.” CONSTRUCTION:- 1 3 2 d2 d3 d1 throat convergent divergent

 

ADVANTAGES OF VENTURI METER LOW PERMENANT PRESSURE LOSS AND HENCE HIGH PRESSURE RECOVERY HIGH ACCURACY OVER WIDE FLOW RANGES, USED FOR COMPRESSIBLE AND INCOMPRESSIBLE BOTH. HIGH REPRODUCIBILITY. LESS POWER LOSS DISADVANTAGES IT OCCUPIES COSIDERABLE SPACE IT IS EXPENSIVE AND BULKY RELATIVELY COMPLEX IN STRUCTURE USED ONLY FOR PERMENANT INSTALLATIONS

Orifice meter It may be installed in pipeline with a minimum of trouble and expense.

Orifice meter THE ORIFICE METER MEASURES THE FLOW RATE BY EQUATION:-  

ROTA METER (VARIABLE AREA METER) PRINCIPAL:- THERE IS A DIFFERENCIAL CONSTRUCTION FOR EACH FLOW RATE AND THE PRESSURE DROP ACROSS THE METER IS CONSTANT AND THE AREA THROUGH WHICH THE FLUID FLOW VARIES WITH FLOW RATE CONSTRUCTION :=

ANY QUESTIONS??? WORKING OF ROTA METER:- IN ROTA METER AS THE FLOW VARIES, THE FLOAT RISES OR FALLS, THUS CHANGING AREA OF THE ANNUAL SPACE. THREE TYPES OF FORCES ARE THERE THE FORCES DUE TO WEIGHT OF FLOAT THE BOUGHT FORCE OF FLUID THE DRAG FORCE ON FLOAT THE MEASURING TAPE IS GIVEN BESIDE THE TUBE.WHEN THE FLOAT MOVES AND BE STEADY THE SCALE WILL MEASURE THE FLOW RATE DIRECTLY. ANY QUESTIONS???