To lessen operational costs in today’s unstable economy, a lab or facility manager with a brand new ICP/Mass Spec system must cost-effectively use cryogenic liquid argon dewars to offer gaseous argon.
With regards to specific critical gases requirements, one attractive option is the usage of Air separation equipment, commonly called dewars, to supply gaseous argon to ICP and ICP/Mass Specs. Argon’s unit cost per cubic foot/gaseous liter is quite a bit lower when sent to your facility in cryogenic liquid form in dewars. However, since these containers keep the gas in a cryogenic form until it is actually dispensed being a gas, there are two problems that can reduce the cost-effectiveness of utilizing this mode of supply.
Ever since the argon is saved in self-pressurizing containers with relief valves and the cryogenic liquid is boiling inside, reserve containers waiting around for the key container to empty over a system will, over time, build internal pressure before the relief valve setting is reached and after that begin to vent excess gas for a price of 2 to 3 percent each day. This is the NER or Normal Evaporation Rate, described in the industry since the “use it or lose it” phenomenon. Around this rate, if 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 eat up whatever savings resulted from your lower unit cost.
Since many of the gas is cryogenic form, pressure within the container will not indicate in case the unit is full, half full or empty. The tiny liquid level indicators in addition to the dewars are hard to see rather than very accurate. Since most gas distribution systems rely solely on pressure to improve from primary to reserve cylinders, false low-pressure readings might cause lab personnel to take out 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 your container is actually empty or contains residual product. IntelliSwitch II 538 Series is definitely the latest within the line 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 to the reserve dewar to supply the gas on the instrument prior to the relief valve opens, drawing down pressure inside the container to your programmed point, and then returning to the principal dewar. This “economizer function” can virtually eliminate losses inside the reserve Cryogenic Movable tank.
Additionally, when primary dewar pressure drops underneath the point in which the device switches to the reserve, IntelliSwitch II will not immediately conclude that this container is empty. It waits a programmable length of time and even though offering the system from the reserve, watches pressure reading around the primary. When the pressure rises 46dexkpky the switchover part of that time period, your computer concludes residual liquid was left in the container and switches returning to it to provide the instrument. It does this repeatedly up until the dewar fails to develop pressure above the programmable switchover point, at which time that it switches on the reserve, and sounds a burglar alarm to indicate the primary is already truly empty. This “look-back feature” cuts down on the residual discarded when you use dewars to below 2 to 3 percent.
Through the elimination of evaporation loss and decreasing the residual left in empty containers, CONCOA’s IntelliSwitch II optimizes the cost savings of making use of CNG Trailer to offer gas to ICP or ICP/Mass Specs.