PREPARED BY:DEEPAK M. BHATIA AVINASH PAL ANUJ CHOWDHRY
ABSTRACT
INTRODUCTION HISTORY:1) In the 1940s, the USA started an extensive program to help synthetic elastomer achieve a worldwide breakthrough. 2) Using high-quality elastomer materials, new technical possibilities eventually opened up for the design and use of diaphragm pumps . 3) Later, hydraulically driven diaphragm compressors came onto the market that were able to produce high pressures of up to 4,000 bar. PUMPS:1) A pump is a device used to move liquids or slurries.
2) It is used to move liquids from lower pressure to higher pressure. DIAPHRAGM PUMPS:1) It’s a diaphragm pump is a positive displacement pump. 2) Uses a combination of the reciprocating action of a rubber or Teflon diaphragm and suitable non-return check valves to pump a fluid.
TYPES OF DIAPHRAGM PUMP:1) In the first type, the diaphragm is sealed with one side in the fluid to be pumped, and the other in air or hydraulic fluid. 2) The second type of diaphragm pump works with volumetric positive displacement, but differs that the prime mover of the diaphragm is neither oil nor air; but is electro-mechanical working through a crank/ geared motor drive. 3) The third type of diaphragm pump has one or more unsealed diaphragms with the fluid to be pumped on both sides.
HIGH-SPEED LIQUID DIAPHRAGM PUMPS A special type of pump based on the technology of diaphragm pump. Employs a mechanical drive for transferring, evacuating and compressing gases. Are also used for siphoning off liquids or air-liquid mixtures.
WORKING
DESIGN, FUNCTION AND PROPERTIES OF DIAPHRAGM PUMPS
1) Elastic Diaphragm 2) Pump Head 3) The Housing 4) The Connecting Rod 5) Clearance 6) The Diaphragm Fixing Screw 7) Transfer Compartment 8) Outlet Pressure Valve 9) Inlet Pressure Valve
OPERATION OF A LIQUID DIAPHRAGM PUMP
CRITERIA FOR SELECTION OF PUMP
Type of gas Required pneumatic performance Gas temperature Temperature of the surroundings Other conditions related to the surroundings Type of motor Possible constructional parameters Mounting position and orientation Operating conditions
DESIGN OF DIAPHRAGM Control Parameters: Maximum speed Nmax = 250 rpm Diameter to stroke ratio = D/L = 2 Maximum diameter D = 3d
2). Chamber diameter D = 3d 3). Chamber depth l = L/2 + 4 mm clearance
Design Parameters: 1). Discharge Discharge= Area * stroke length *speed Qmax = π/4 * d2 * L * Nmax
4). Eccentricity e = l/2 5). Control volume = π/4 * D2 * L
MODEL PERFORMANCE CURVE
D is c h a r g e ,Q a c t V s . S p e e d
D is c h a r g e ,Q t h V s . S p e e d 3 .5
4 2 7 5 , 3 .5 4 2 5 5 , 3 .2 8 1
3 .5 3
2 7 5 , 2 .9 2 5 5 , 2 .7 5
2 .5
2 .5
1 8 5 , 2 .3 8 1 5 5 , 1 .9 9 5
2 1 .5
discharge (lpm)
Discharge,Qth (lpm)
3
1 0 5 , 1 .3 5 1 8 5 , 1 .0 9 4 5 0 , 0 .6 4 3 2 0 , 0 .2 5 7
1 0 .5 0 0
50
100
150
200
S p e e d (rp m )
1 8 5 , 2 .0 5
2
1 5 5 , 1 .7 5
1 .5 1 0 5 , 1 .2 85, 1
1
5 0 , 0 .6
0 .5
2 0 , 0 .2 4 5
0
250
300
0
50
100
150
200
s p e e d (rp m )
250
300
CONCLUSION From the graph of discharge versus speed curve, it is noted that actual discharge deviates more and more from theoretical discharge as the speed increases, this means slip increases rapidly with higher speed. Also the eccentric drive is there which gives more fluctuation. A major advantage of diaphragm pumps is that the pumped liquid does not come into contact with most of the working parts of the pump. The diaphragm pump offers further advantages over oil-lubricated pumps such as it is an Oil free pump, it has High gas tightness capacity, is highly reliable etc.
FUTURE SCOPES Principle of diaphragm pump can be used to make miniature pump i.e. micro pump which will be useful for space and medical application. Following is the micro pump concept. There is a range of NASA experiments, instruments and applications where miniature pumps are needed. To address such needs, a piezo electrically actuated miniature pump is being developed under a NASA Code S PIDDP task.
Figure 24: Micro diaphragm gas sampling pump e.g. for analytical technology
REFERENCES Books Pump Handbook-Igor J. Karassik, JOSEPH P. Messina, Paul Cooper, CHARLES C. Held. Material selection in mechanical design-Michael & Ash Fluid Movers by Nicholas P. Chopey Pumps & Pumping operation by Nicholas P. Pawl Metering pump handbook by Robert E. McCabe Pumping and Processing principle & practice Fluid Movers Water well and pump Engineering by A M Michael & S D Khepar Websites www.knf.com www.positivemetering.com www.pumps_in_stack.com/diaphragm_pump_design.html www.howstuffworks.com www.wikipedia.com www.ebookworld.com www.syudentshangout.com
