Hughes Pumps, based in West Sussex, UK, has recently supplied three HPS5000 high-pressure pump sets to one of the world’s leading steel manufacturers based in South Korea as part of a water atomising project, a process that has the potential to handle huge throughputs of metal on a single melt stream, potentially delivering increasing performance levels and low operating costs.
In the water atomising process, molten metal is poured through a high-pressure water spray ring fitted with high-pressure fanjet nozzles that atomises the molten metal into metal powder, which is typically used for sintering engineering components.
Water atomisation was chosen because it produces irregular shaped particles as well as allowing large processing rates of up to around 1000 kg (2200 lb) per minute. This irregular shape offers the benefits of a much larger surface area, which when used in refining applications allows a greater surface area for chemical attack. Powder Metallurgy (PM) parts produced by pressing and sintering rely upon the irregular shapes to produce the compressibility and locking nature that holds the parts in their green shape – a certain strength that allows easier handling and sintering.
The Hughes Pump’s system comprised of two duty and one standby pump, each with a performance of 750 lpm at 140 bar (200 gpm at 2,000 psi) giving a combined performance of 1500 lpm at 140 bar (400 gpm at 2,000 psi). Each pump was driven by a 200 kW (270 hp) electric motor.
The HPS5000 pumps were chosen for their quintuplex (5 cylinder) design, which produces a much smoother output than triplex (3 cylinder) pumps. The pumps were also fitted with discharge pulsation dampers to smooth the output even further. This was a prerequisite due to the extensive run of rigid stainless steel discharge pipework installed on the system.
The pumps incorporated pneumatic dump/pressure regulating valves that were controlled by the central PLC to enable remote on/off load control and pressure adjustment.
As with all Hughes Pump models, the HPS5000 pump is pressure lubricated and oil cooled as standard. As the process water was to be re-cycled and therefore subject to heat rise, increased size oil coolers were fitted to the pumps to allow for the incoming water supply at 40°C (104°F).