A peristaltic pump is provided having an adjustable flow regulation provided by an adjustable axial elongation means for the variable elongation of resilient tubing disposed between the associated rotors of a rotary peristaltic pump or the plurality of reciprocal pushers or fingers in a linear peristaltic pump to provide a radial compression of successive sections of the resilient tubing. The rotary or linear peristaltic pump includes a calibrated display and a variable speed electric motor having forward and reversing capabilities along with computer interface control for precisely metering and monitoring the volume of liquids for medical, biological and laboratory applications. Individual adjustable flow regulation is provided for each of the resilient tubes in the peristaltic pump by providing for the independent adjustable elongation of the flexible tubing in relation to the plurality of reciprocal pushers or fingers in the linear peristaltic pump or the associated rollers in a rotary peristaltic pump in combination with a means for ascertaining and displaying the speed of the drive motor.
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JOSEPH PAUL P.V.
The process of peristalsis is used by peristaltic pump
Peristalsis is the process of involuntary wave like successive muscular contraction by which food is moved through the digestive tract
The rollers squeezes the tube forcing the fluid along.
Restitution creates a vacuum which further draws the fluid into the pump.
Fluid only comes into contact with the tube. (no direct contact with the moving part)
It is a positive displacement pump
Gentle pumping action
Output not uniform
The volume of fluid in between the 2 adjacent rollers is called as FLUID PILLOW.
Flow Rate = volume of fluid pillow * speed of rotor(rpm) * no of pillows in 1 min.
EFFECT OF ROLLERS
If the no of rollers increase:-
1.flow rate decreases.
2.more uniform flow
3.high exit pressure.
4.less tube life
If the no of rollers decrease:-
1.flow rate increases.
2.less uniform flow
3.low exit pressure
4.more tube life
1. ROTARY PUMP
2. LINEAR PUMP
(used to pump heavily viscous fluids)
3. 360 DEGREE PUMP
(large flow rate, long tube life, low exit pressure)
Fixed speed type
Variable speed type
Digital input type
The tube of Peristaltic pump is its “heart”.
Its restitution creates suction
its strength resists pressure
its flex resistance determines pumping life
its bore defines the flow rate
It’s the most important part
Polyvinyl chloride(PVC) (hard, cheap. 10 70 c)
Natural rubber( very cheap. 80-20 c)
Acrylonitrile butadiene rubber( Buna N) (resistant to oils, grease, alkalis, detergents. 80 -10 c)
Ethylene propylene diene rubber(EPDR) (resistant to ketones, alcohols, acids. 90 -10)
Chlorosuphonyl polyethylene rubber(CSR) (resistant to bases & other oxidizing fluids. 80 -10 c)
Marpene, bioprene, chemsure, neoprene, stapure, pumpsil, fluorel, tygon, viton etc.
Inner layer in various types of rubber
Intermediate layer Reinforced with nylon
Outer layer precision-machined
Outer most layer which is roughened
Fluid does not contact any part of the pump except the tubing.
No Seals to leak, No valves to clog or wear
Doesn’t require expensive ancillary equipment
Fewer parts to inventory
Self priming (up to 30 ft. (8.8 m) in some models)
tubing materials can be easily sterilized.
Easily cleaned at the end of the day, saves time
Easily repaired (just have to change the tube)
Thus a peristaltic pump with a new pipe is like a new pump
Easy to use, little operator training required
Many types of tubing are available.
Wide selection of drives/motors(variable speed)
Is fully reversible to blow out clogged suction and drain lines safely
Gentle pumping action
No back flow(slip)
Same pump could be used to pump other fluids (just change the tube to suitable one)
Ultimately cost effective
Flow not perfectly uniform
Cannot pump above 10/11 meters
Uneconomical for long distance pumping.
High exit pressures cannot be obtained
Selection of tube should be done carefully.
Manufacturing of glues & emulsions
Blood transfusions & dialysis machines
Waste water & sewage treatment
Nuclear power plants
Manufacturing of bio-diesel
Pumping concrete in large construction works
Under ground water sampling
Aquariums & sea water pumping.
Thus peristaltic pumps have very low maintenance cost and a trouble free service life.
Its operations are simple and its easily repairable.
Best suited for pumping viscous, colloidal, aggressive, volatile liquids.
It has a promising future because as time passes more and more highly developed & reinforced tube materials are discovered.