What is the Principle of a Glove Box?
A glove box is an enclosure or a containment glove box used for protection purposes in sectors such as pharmaceutical-medical, chemical, industrial, aeronautics, etc. It generally has a stainless-steel structure and a hermetic and watertight main chamber with transparent sides. For maximum protection, handling gloves are attached to the walls so that the operator can work from the outside while respecting the containment. A glove box systematically has at least one transfer airlock to facilitate the entry and exit of the elements to be protected and the instrumentation. A safety flow prevents risky phenomena by automatically preventing the propagation of dangerous products.
The enclosure of a glove box is inert or purified, generally by means of inert gas, a neutral gas. It is said to be nitrogen-regulated when its purification system uses nitrogen (N2). The result is an atmosphere of very high purity, free of all traces.
All About the Purification System
A purification system circulates the neutral gas, in this case nitrogen (but in some specific cases nitrogen will be replaced by argon) for the case of a glove box regulated under nitrogen. This circulation is continuous, in a closed loop between the glove box and the purifier. After passing through the purification unit, the purified gas is reinjected into the glove box. The purification of the gas with the purification system maintains a pure and stable atmosphere inside the hermetic enclosure.
The purification system consists of various components: scrubber, molecular sieve for H2O absorption, catalyst for O2 absorption, hermetic circulator, purification circuit, analysers and sensors. The pressure regulation, whose aim is to maintain the pressure in the glove box at a level slightly higher than the atmospheric pressure, is relayed by a control box with PLC (Program Logical Controller). This also ensures the automatic regeneration of the scrubber by reactivating the scrubbing charges when they are saturated. The control panel is connected to a touch screen that communicates directly and continuously with the plant’s sensors. Important data are continuously displayed on the screen (O2, H2O, pressure, temperature) as well as menus facilitating the operations or allowing to ensure at any moment the good general functioning: graphs, configurable operations, configurable alarms, purges etc…
What are the Specificities of a Nitrogen-regulated Glovebox?
A nitrogen-regulated glove box reinforces the protection of the products or of a process or an experiment. In this type of glove box, integrated devices allow the recirculation of nitrogen in a closed loop on a purification column integrated in the circuit. A fan forces the nitrogen collected to pass over this purification column filled with chemical species, in this case active copper for the removal of oxygen and molecular sieve for the removal of moisture. Due to this continuous recirculation principle, the nitrogen is purified before being reinjected into the glove box.
In addition, the constraints required by each application must be scrupulously respected during containment. The temperature, pressure and internal conditions of the glove box are regulated from a control panel. With a nitrogen purification unit, the pressure is, for example, maintained above atmospheric pressure, then the oxygen and humidity levels are kept below 1 ppm. Micro-pollutions are evacuated out of the glove box and the internal environment remains extremely pure.
Applications of a Glove Box Under Nitrogen
The nitrogen-regulated glove box is best suited for applications where substances, materials or materials sensitive to air, moisture or humidity have to be handled. It provides an anhydrous, anaerobic and ultra-clean working environment. It is particularly suitable for nuclear applications (handling radioactive elements), chemical and physical processes (development of photovoltaic cells, OLEDs and organic transistors), biology and for pharmaceutical and medical industrial processes.
What to remember:
- A nitrogen-regulated glove box is a glove box whose purification system is powered by N2,
- It works in overpressure,
- It is intended exclusively for applications requiring containment in inert atmosphere,
- It is dedicated to the protection of products or processes.