To reduce operational costs in today’s unstable economy, a lab or facility manager with a new ICP/Mass Spec system must cost-effectively use cryogenic liquid argon dewars to supply gaseous argon.
With regards to specific critical gases requirements, one attractive choice is the use of Cryogenic storage Dewar, commonly called dewars, to deliver gaseous argon to ICP and ICP/Mass Specs. Argon’s unit cost per cubic foot/gaseous liter is significantly lower when shipped to your facility in cryogenic liquid form in dewars. However, as these containers keep the gas in the cryogenic form until it is dispensed being a gas, there are two concerns that can lessen the cost-effectiveness of utilizing this mode of supply.
Because the argon is saved in self-pressurizing containers with relief valves and also the cryogenic liquid is boiling inside, reserve containers expecting the primary container to empty over a system will, over time, build internal pressure until the relief valve setting is reached and then set out to vent excess gas at a rate of 2 to 3 percent each day. Here is the NER or Normal Evaporation Rate, described in the business as being the “use it or lose it” phenomenon. Around this rate, when the reserve cylinder of argon contains 4,500 cubic feet of gas, it equals losing 135 cubic feet daily it sits in reserve. It wouldn’t take very long to nibble on up whatever savings resulted through the lower unit cost.
Since most of the gas is at cryogenic form, the stress within the container does not indicate in the event the unit is full, half full or empty. The tiny liquid level indicators along with the dewars are hard to read through rather than very accurate. As most gas distribution systems rely solely on pressure to change from primary to reserve cylinders, false low-pressure readings could cause lab personnel to get rid of containers with as much as 25 % from the contents still inside.
Solution: CONCOA’s Intelligent Gas Distribution System IntelliSwitch II continuously monitors your reserve container’s pressure, using programmed software logic to ascertain if your container is truly empty or contains residual product. IntelliSwitch II 538 Series will be the latest in the brand of computer-controlled gas distribution switchover systems using very accurate transducers to observe both primary and reserve inlet pressures. Proprietary software logic uses this info to drastically reduce evaporation loss by switching to the reserve dewar to provide the gas to the instrument just before the relief valve opens, drawing down pressure from the container to some programmed point, then returning to the key dewar. This “economizer function” can virtually eliminate losses inside the reserve LNG filling Station.
Additionally, when primary dewar pressure drops below the point in which the device switches to the reserve, IntelliSwitch II is not going to immediately conclude that this container is empty. It waits a programmable timeframe and although supplying the system from the reserve, watches the strain reading about the primary. In the event the pressure rises 46dexkpky the switchover part of that point period, the pc concludes residual liquid was left within the container and switches straight back to it to offer the instrument. It can do this repeatedly till the dewar fails to develop pressure above the programmable switchover point, in which time that it switches to the reserve, and sounds an alarm to indicate the primary is currently truly empty. This “look-back feature” cuts down on the residual discarded when working with dewars to under 2 to 3 percent.
By eliminating evaporation loss and reducing the residual left in empty containers, CONCOA’s IntelliSwitch II optimizes the fee savings of making use of Gas Cylinder to deliver gas to ICP or ICP/Mass Specs.