To lower 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 option is the usage of Cryogenic storage Dewar, commonly called dewars, to supply 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, since these containers store the gas inside a cryogenic form until it is actually dispensed like a gas, the two main conditions that can decrease the cost-effectiveness of employing this mode of supply.
Because the argon is held in self-pressurizing containers with relief valves as well as the cryogenic liquid is boiling inside, reserve containers awaiting the key container to empty over a system will, after a while, build internal pressure until the relief valve setting is reached after which begin to vent excess gas at a rate of 2 to 3 percent per day. This is actually the NER or Normal Evaporation Rate, referred to in the market since 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 every day it sits in reserve. It wouldn’t require much time to nibble on up whatever savings resulted through the lower unit cost.
Since many of the gas is in cryogenic form, the pressure within the container is not going to indicate in case the unit is full, half full or empty. The small liquid level indicators on top of the dewars are difficult 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 could cause lab personnel to eliminate 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 determine if a container is definitely empty or contains residual product. IntelliSwitch II 538 Series will be the latest within the brand of computer-controlled gas distribution switchover systems using very accurate transducers to monitor both primary and reserve inlet pressures. Proprietary software logic uses this data to drastically reduce evaporation loss by switching towards the reserve dewar to supply the gas for the instrument prior to the relief valve opens, drawing down pressure from the container to some programmed point, and after that returning to the key dewar. This “economizer function” can virtually eliminate losses within the reserve Cryogenic ISO Tank Container.
Additionally, when primary dewar pressure drops underneath the point at 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 although offering the system in the reserve, watches the pressure reading in the primary. When the pressure rises 46dexkpky the switchover point in this time period, the pc concludes residual liquid was left from the container and switches back to it to deliver the instrument. It does this repeatedly before the dewar fails to build pressure above the programmable switchover point, where time it switches to the reserve, and sounds a burglar alarm to indicate the principal is now truly empty. This “look-back feature” decreases the residual discarded when utilizing dewars to less than 2 to 3 percent.
Through the elimination of evaporation loss and decreasing the residual left in empty containers, CONCOA’s IntelliSwitch II optimizes the price savings of using Cryogenic Centrifugal Pump to supply gas to ICP or ICP/Mass Specs.