The occasional gas purge of a glove box to replace the ambient air with an inert gas is something that glove box users accept will take some time, an hour or more for the average glove box. But for those glove box users that need to access the main glove box chamber frequently due to the requirements of the process operation, these time scales can present serious production problems. The alternative of investing in an evacuable glove box must be the rapid gas purge system.

The standard practice of glove box gas purge involves releasing a gas into an enclosed chamber (the glove box) and venting the gas through a small aperture so as to prevent the backflow of oxygen. This of necessity increases the pressure within the glove box most of which are limited to less than 50 mbar (pressure) to avoid permanent distortion or failure.

Our rapid gas purge system relies upon the accurate measurement of glove box pressure, the control of gas entering the glove box under positive pressure and exiting under negative pressure, all at a high rate of gas flow that substantially reduces the time.

The control is at all times maintained within the glove box design limitations and a high factor of safety is calculated into the set up and back-up protection which forms part of the design qualification.

A rapid gas purge system can operate at less than 5% of the normal gas purge time providing adequate gas supply and feed pipelines are available. The system is entirely safe in operation, but users must accept an increased noise level due to the very high discharge velocity needed to achieve the time reduction.

In practice a balance is struck between available gas supply, feed pipelines and target gas purge time.

Rapid gas purge systems require accurate pressure measurement and this makes it unsuitable for flexible enclosures.

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