Performance-Tested Controlled Atmosphere Glove Boxes

Enhanced particulate containment is an important feature of Protector® Filtered Glove Boxes (Labconco Corp., Kansas City, MO) (Figure 1). In addition, the glove boxes provide the operator with real-time performance data on internal static pressure, air volume flow rates in cubic feet per minute (CFM), air changes per minute (ACM), and main chamber pressure (inches of water).

Figure 1 - Protector Glove Boxes.

The glove boxes offer all of the advantages of a low-volume, HEPA-filtered ventilation enclosure system, but provide a totally isolated working environment. Blower control can be used to achieve high rates of contaminant dilution within the totally enclosed main chamber, which provides an absolute level of containment for chemical hazards that cannot be achieved with open-sash fumehoods and balance enclosures. The built-in blower and speed control provide filtered airflow rates from 15 CFM to 85 CFM. Glove boxes with 99.99%-efficient HEPA or 99.999%-efficient ultralow-penetration air (ULPA) filters are available with bag-in/bag-out filter capabilities. Common applications include nanoparticulate manipulation and the weighing of hazardous powders.

During testing of the Protector Filtered Glove Box, airborne particulate levels, measured under both negative and positive pressure conditions within the main chamber, were reduced to below ISO Class 5 conditions (equivalent to Class 100) and achieved ISO Class 3 conditions (equivalent to Class 1) in less than 5 min at all operational airflow volumes. Airborne particulate cleanliness (measured under negative pressure) within the main chamber of the glove box exceeded ISO Class 5 conditions (equivalent to Class 100) and exceeded ISO Class 3 conditions (equivalent to Class 1) at minimum blower speed, 50%, and maximum operational airflow volumes.

Protector Filtered Glove Boxes are supplied with a molded one-piece fiberglass or stainless steel liner with either a 99.99%-efficient HEPA filter or a 99.999%-efficient ULPA filter to prevent contaminants from entering or leaving the glove box chamber.

Protector Controlled Atmosphere Glove Boxes feature an LCD with microprocessor controls for automatically evacuating and refilling the glove box main chamber up to 499 times and the transfer chamber up to 199 times with clean inert nitrogen or argon gas. This purification operation can quickly reduce ambient levels of oxygen and moisture to 1-ppm concentration levels while saving on the consumption of inert gas. The glove boxes are factory leak-tested with a mass spectrometer while pressurized with helium at 5 in. of water gauge. There are no detectable leaks greater than 1 × 10–6 mL/sec. All Protector Controlled Atmosphere Glove Boxes exceed Class 1 atmosphere containment conditions for oxygen permeation <1.67 ppm/min per the ISO 10648-2 test method.

The glove boxes are offered in two construction materials. For applications involving mineral acids, the one-piece molded fiberglass liner with clear acrylic inner and outer transfer chamber doors is the best choice. These controlled atmosphere glove boxes are performance tested to maintain oxygen levels as low as 0.4 ppm and moisture levels as low as 2 ppm. Fiberglass glove boxes offer an oxygen permeation rate of <0.3 ppm/min per ISO 10648-2. Interior illumination exceeds 120 foot-candles.

Glove boxes featuring a stainless steel liner with Type 304 stainless steel inner and outer transfer chamber doors are best suited for applications that are sensitive to organic chemicals. These glove boxes are performance tested to maintain oxygen levels as low as 0.2 ppm and moisture levels as low as 1 ppm. Stainless steel glove boxes offer an oxygen permeation rate of <0.16 ppm/min per ISO 10648-2. Interior illumination exceeds 80 foot-candles.

The glove boxes feature a factory-installed, rear-mounted, low-profile stainless steel pressure relief bubbler at ±6 in. of water gauge and space-saving inner and outer transfer chamber doors that pivot upward and are counterbalanced and equipped with quick-latches.

The Atmospure Re-Gen Purification System (Labconco) is a separate regenerative oxygen and moisture removal system. The system can be connected to any controlled atmosphere glove box for reducing and maintaining oxygen/moisture levels below 1 ppm over long time periods. Typical inert glove box applications require regenerations once every four weeks. The regeneration procedure is semiautomatic with one-button startup function.

Mr. Applequist is Product Manager, Labconco Corp., 8811 Prospect Ave., Kansas City, MO 64132-2663, U.S.A.; tel.: 816-822-3705; e-mail: [email protected].

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