Peristaltic pump

A peristaltic pump is a type of positive displacement pump used for pumping a variety of fluids, they are also commonly known as roller pumps. The fluid is contained within a flexible tube fitted inside a circular pump casing (though linear peristaltic pumps have been made). A rotor with a number of 'rollers', 'shoes', 'wipers', or 'lobes' attached to the external circumference of the rotor compresses the flexible tube. As the rotor turns, the part of the tube under compression is pinched closed (or 'occludes') thus forcing the fluid to be pumped to move through the tube. Additionally, as the tube opens to its natural state after the passing of the cam ('restitution' or 'resilience') fluid flow is induced to the pump. This process is called peristalsis and is used in many biological systems such as the gastrointestinal tract. Typically, there will be two or more rollers, or wipers, occluding the tube, trapping between them a body of fluid. The body of fluid is then transported, at ambient pressure, toward the pump outlet. Peristaltic pumps may run continuously, or they may be indexed through partial revolutions to deliver smaller amounts of fluid. A peristaltic pump is a type of positive displacement pump used for pumping a variety of fluids, they are also commonly known as roller pumps. The fluid is contained within a flexible tube fitted inside a circular pump casing (though linear peristaltic pumps have been made). A rotor with a number of 'rollers', 'shoes', 'wipers', or 'lobes' attached to the external circumference of the rotor compresses the flexible tube. As the rotor turns, the part of the tube under compression is pinched closed (or 'occludes') thus forcing the fluid to be pumped to move through the tube. Additionally, as the tube opens to its natural state after the passing of the cam ('restitution' or 'resilience') fluid flow is induced to the pump. This process is called peristalsis and is used in many biological systems such as the gastrointestinal tract. Typically, there will be two or more rollers, or wipers, occluding the tube, trapping between them a body of fluid. The body of fluid is then transported, at ambient pressure, toward the pump outlet. Peristaltic pumps may run continuously, or they may be indexed through partial revolutions to deliver smaller amounts of fluid. The peristaltic pump was first patented in the United States by Rufus Porter and J.D. Bradley in 1855 (U.S. Patent number 12753) as a well pump, and later by Eugene Allen in 1881 (U.S. Patent number 249285) for blood transfusions. It was developed by heart surgeon Dr. Michael DeBakey for blood transfusions while he was a medical student in 1932 and later used by him for cardiopulmonary bypass systems. A specialized nonocclusive roller pump (US Patent 5222880) using soft flat tubing was developed in 1992 for cardiopulmonary bypass systems. The first technically and commercially viable peristaltic pump for use outside the laboratory was developed by Bernard Refson, an inventor who went on to establish Watson-Marlow Fluid Technology Group, a company that is widely recognised today as being the world leader in peristaltic pump manufacture. Peristaltic pumps are typically used to pump clean/sterile or aggressive fluids without exposing those fluids to contamination from exposed pump components. Some common applications include pumping IV fluids through an infusion device, apheresis, aggressive chemicals, high solids slurries and other materials where isolation of the product from the environment, and the environment from the product, are critical. It is also used in heart-lung machines to circulate blood during a bypass surgery, and in hemodialysis systems, as the pump does not cause significant hemolysis. Peristaltic pumps are also used in a wide variety of industrial applications, especially agriculture as they are well suited for common agricultural chemicals. Their unique design makes roller pumps especially suited to pumping abrasives and viscous fluids.