Cyclotron Facility Achieves 25% Increase in Suction Pressure by Installing Suction Diffuser Flex
The Indiana University Cyclotron Facility (IUCF) located in Bloomington Indiana is a state of the art multidisciplinary facility performing research, development and application of accelerator physics, nuclear physics, nuclear science, and material science. Research activities from NASA and around the world are carried out at the IUCF.
Generating subatomic particle beams traveling at almost the speed of light, the accelerator at the IUCF is a life-saving marvel. The proton beam from the accelerator is used for medical treatments, especially the irradiation of cancerous tumors. In addition, two beam lines were built with support from NASA and are used to test components that will be flown into outer space as part of the Radiation Effects Research Program (RERP) that simulates years of exposure to the environment of space.
At peak operation the IUCF requires 4.0 megawatts of power to operate. The accelerator alone requires 1.5 megawatts to operate. With this power load, cooling of the equipment is critical, making the chilled water system a very important part of the operation.
“When the facility was first built,” comments Bill Starks, Mechanical Designer at IUCF, “we needed to install two, 200 HP, 3,700 GPM chilled water pumps in an area with inadequate overhead clearance. Vertical split case double suction pumps were selected.
“When we first started up the pumps,” he continued, “we were going through bearings and wearing out the impellers in 3 months time. The pump manufacturers confirmed it was a piping issue. It’s very critical, especially on a split case double suction pump. It has to be equal flow to each side. Otherwise, if the flow is concentrated to one side, it will result in an uneven thrust load on the impeller. The uneven load would wear out the bearings and also cause the impeller to shift to the side. Eventually the impeller will start hitting the housing. The bearings go bad, the housing goes bad and the impeller goes bad.”
Starks was able to improve that situation by doing a more critical alignment of the motor in the pump, yet bearings and impellers were still wearing out after just six months.
When the Suction Diffuser Flex was installed the results were immediately evident. “The Suction Diffuser Flex increased the suction pressure by about 25% from 3.5 pounds to 4.5 pounds,” detailed Bill Starks.” And it increased our output pressure by 10 PSI at the same flow rate.
“So this is a real big boost for us,” he continued, “and we’ve been running six months without bearing failure or any increase in noise. Usually the bearings would start to get noisier or you start wearing the impeller and you get some type of cavitation noise. Right now it’s still the same as day one. We’re actually running on what was our standby pump and reserving our main pump, which has the old style diffuser on it.”
IUCF is so pleased with the performance they are planning to replace their diffuser on the main pump with the Suction Diffuser Flex.