To lessen 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 deliver gaseous argon.
In relation to specific critical gases requirements, one attractive option is the application 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 a lot lower when sent to your facility in cryogenic liquid form in dewars. However, as these containers keep the gas within a cryogenic form until it can be dispensed as a gas, there are two problems that can reduce the cost-effectiveness of utilizing this mode of supply.
Considering that the argon is saved in self-pressurizing containers with relief valves along with the cryogenic liquid is boiling inside, reserve containers awaiting the main container to empty over a system will, after a while, build internal pressure before the relief valve setting is reached and after that start to vent excess gas for a price of 2 to 3 percent each day. This is basically the NER or Normal Evaporation Rate, described in the marketplace as being the “use it or lose it” phenomenon. At this rate, if the reserve cylinder of argon contains 4,500 cubic feet of gas, it equals losing 135 cubic feet every single day it sits in reserve. It wouldn’t take long to consume up whatever savings resulted from the lower unit cost.
Since most of the gas is cryogenic form, pressure from the container does not indicate in the event the unit is full, half full or empty. The small liquid level indicators on the top of the dewars take time and effort to see instead of very accurate. Since the majority gas distribution systems rely solely on pressure to alter from primary to reserve cylinders, false low-pressure readings can cause lab personnel to eliminate containers with just as much as 25 percent of your contents still inside.
Solution: CONCOA’s Intelligent Gas Distribution System IntelliSwitch II continuously monitors your reserve container’s pressure, using programmed software logic to figure out if a container is definitely empty or contains residual product. IntelliSwitch II 538 Series will be the latest within the collection 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 for the reserve dewar to supply the gas on the instrument before the relief valve opens, drawing down pressure in the container into a programmed point, and then going back to the principal dewar. This “economizer function” can virtually eliminate losses in the reserve LNG filling Station.
Additionally, when primary dewar pressure drops beneath the point from which the device switches towards the reserve, IntelliSwitch II fails to immediately conclude the container is empty. It waits a programmable length of time and while offering the system in the reserve, watches the stress reading about the primary. In the event the pressure rises 46dexkpky the switchover point in this time period, the computer concludes residual liquid was left from the container and switches returning to it to deliver the instrument. It will this repeatedly before the dewar fails to develop pressure over the programmable switchover point, from which time that it switches for the reserve, and sounds a burglar alarm to indicate the principal is currently truly empty. This “look-back feature” cuts down on the residual discarded when working with dewars to lower than 2 to 3 percent.
Through the elimination of evaporation loss and lowering the residual left in empty containers, CONCOA’s IntelliSwitch II optimizes the cost savings of using Gas Cylinder to deliver gas to ICP or ICP/Mass Specs.