History[edit | edit source]
In 1996 an English engineer, Frederick Philip Selwyn, patented a 'fluid pressure amplifier' which differed in many ways to the contemporary ram pump technology by the development of a venturi effectW waste valve.
This utilises the low pressure generated by high velocity water flow around a curve-shaped elastomericW valve (with low pressure loss) to allow a valve design that enables rapid closure and with a relatively small cross sectional area and low weight. This venturi valve is configured as a ring section positioned around the supply inlet of the pump with the delivery outlet of the pump being directly in line. This allowed the pump structure to be concentric and therefore inherently strong and upon closure of the valve, permits efficient water delivery by acting in line with the supply via a second smaller venturi effect delivery non return valveW. The elastomeric material and operation of these valves also allows them to self-return without weight or spring assistance.
A pressure vesselW installed on a tee connected to the delivery port of the pump provides the pulsed flow accumulation means. This unique technology and design dramatically reduced the weight, manufacturing cost and number of components required - as well as providing an overall improvement in efficiency. Additional patents granted to Selwyn have since been developed by UK companies Papa Ltd and Water Powered Technologies Ltd of BudeW, Cornwall, further enhancing the technology to include a composite materialW injection-mouldedW pump allowing for relatively low cost mass productionW whilst maintaining high strength, low weight and high performance previously only attainable with metal units.
Other Papa ram pump related innovations include:
i) Sureflow valve - an automatic regulator valve system which can be simply installed into the Papa pump exhaust port to allow the maximum utilisation of water supply from low or seasonally variable sources without the need to manually adjust the pump.
ii) Venturo pumps - scaled-up ram pumps with 500mm and 1 metre diameter inlets for large river, marine tidal and flood applications.
How the Papa ram pump works[edit | edit source]
Construction[edit | edit source]
The main body parts of the Papa pump are manufactured from a high-performance engineering composite which was specifically developed by Italian company Lati S.p.A. for metal replacement applications. This results in a pump weight of 2kg compared to a 2" traditional ram pump which weighs around 95kg.
The integral main valve and non-return valves are manufactured from an elastomericW compound specially developed by Water Powered Technologies in conjunction with a number of UK suppliers over several years to ensure optimum performance under the many different water conditions which may be encountered. A spring-loaded pressure-relief valveW is incorporated into the pump which also doubles as a manual bleed valve.
Unlike a traditional ram pump which contains an integral pressure vessel, the Papa ram pump is supplied with a separate pressure vessel and external non-return valve mounted as part of a hose assembly. This separate pressure vessel contains a diaphragm whereby the air cushion is separated from the water. Adjusting the air pressure in the pressure vessel is carried out by using a standard hand or foot pump. The pressure should be set to 0.5 barW below the delivery head pressure (10m = 1 bar); for example with a delivery head of 50m, the air pressure should be set to 4.5bar.
Performance[edit | edit source]
Applications[edit | edit source]
Many applications for the Papa pump exist, including livestock watering, agriculture, horticulture, irrigation, rainwater harvesting, aquacultureW, catchment management etc. Papa pumps have also been used in water treatmentW and other water utilityW applications, especially beneficial where the utility is in a remote area. Application examples:
References[edit | edit source]
- Frederick Philip Selwyn, "Fluid pressure amplifier," U.S. Patent no. 6,206,041 (filed: 2 April 1997 ; issued: 27 March 2001).
- Water Powered Technologies – Composite Hydraulic Ram Pump inventors and patentees.
- Sureflow ram pump control system
- Venturo high volume ram pumps
- Hydromentum rainwater harvesting system with Papa ram pump technology system
- Seradisc new technology adjustable filter screen
- Lati S.p.A. manufacturers of hi-tech thermoplastics