The coil pumps

A family of Coil Pumps has been developed at Loughborough University over the last 10 years by the author. The coil pump, sometimes known as the 'hydrostatic pump', was known and used in the 18th and 19th centuries, since then it appears to have been forgotten. Laboratory investigations lead to a theory for predicting the behaviour of this little known pump The theory is based on an assessment of the boundary levels of the liquid plugs within the loops. From this work, two types of suction pump were derived and the lift pump theory was developed and adapted to predict their behaviour. One suction pump was based on one helical coil and it required a regulated air supply. The second pump used two helical coils 'back to back' one taking water into the pump and the other (of larger capacity) withdrawing it. Laboratory tests were carried out on a number of versions of both suction pumps and the experimental results agreed well with those produced by the theory. Practical applications of this family of pumps included a low cost stream powered lift pump, a dosing pump, a sewage suction pump and a sewage treatment process.