Helium received national attention in 2010 when the helium shortage, and subsequent rising prices, gained mainstream attention. Since then more and more companies have installed helium recovery systems to capture and reuse the helium in industrial applications. But as Kevin Rogers, senior account manager from Production Control Units, Inc, explains as these systems become more commonplace, another problem arises: how to keep or increase the efficiency of the systems as they age. A manufacturer of roof top HVAC systems had this exact problem. A particular facility of this manufacturer had been put on helium allocation. As a result, the facility was required to find a way to reduce helium usage within existing systems. “The facility manager contacted the company I work for, Production Control Units, a Dayton, Ohio company that engineers process equipment, regarding increasing the efficiency of its helium recovery system. The helium is used in testing its products’ refrigeration system for leaks,” states Rogers
Reuse the helium lost during helium makeup
After analysing the efficiency of the helium recovery system, it was determined that improvements to the system would help reduce helium usage. The solution was to retrofit the helium recovery system to not only reduce the helium discharged during the helium makeup in the system, but to reuse it. Rogers added, “Helium make up occurs when the helium concentration is outside specification as a result of normal processes. To get the helium concentration back to specification, pure helium is added to the system.” “As helium is added to the system, the pressure increases. When the increase in pressure exceeds the high pressure limit, a valve is opened to reduce the pressure, venting the helium mixture into the atmosphere. This adding and venting continues until the concentration level is within limits.” With the retrofit, the vented helium is captured and stored in an auxiliary tank. The vented gas was then able to be added with the pure helium and reused. The facility was able to divert its helium allocation to other facilities.
This facility was able to reduce its helium purchase from more than 200,000 standard cubic feet (scf) per month to less than 100,000scf per month as a direct result of this change. Today, the Bureau of Land Management has set helium crude prices to $106.00 per thousand cubic feet (mcf) from October, 1, 2014 until September 30, 2015. Reducing its helium purchase saved this facility $127,200 this year alone, just from retrofitting a single helium recovery system.
Don’t forget the analysis
“Before you start retrofitting your system, one word of warning. Make sure you or an outside engineering firm conduct an analysis to determine the current efficiency of the helium recovery system first. If its lower than 95% then retrofitting may help,” warns Rogers. The improvements can be quantified by a reduction in purchased helium as in the case of the above story, or by installing mass flow meters to monitor helium leaving the system and helium returning to the system. If the efficiency of the helium recovery system is in the 95% range and it’s still not capturing enough helium for you, then it may be time to invest in a new system.