Inert gas purging

This eliminates the vapor space but sealing the edge can be a problem. Double seals can help and sometimes a fixed roof is also added above the floating roof to help capture any leaks from the seal. However in this case, the space between the fixed and floating roof now breathes and an inert gas purge of this space would typically be used. The inert gas would be vented to atmosphere after treatment. 

A purge-swing adsorpfion cycle is usually considered to be one in which desorpfion takes place at the same temperature and total pressure as adsorpfion. Desorpdon is accomplished either by pardal-pressure reduction using an inert gas purge or by adsorbate displace-... 

Figure 15-4. Seai oii system, gas vent inert-gas purge...

Blakey and Orlando give useful methods for determining inert gas purging requirements. 

The gas is non-flammable, and is used for inert gas purging. Because it is 1.5 times heavier than air it may accumulate at low level. The general handling precautions are those in Table 9.3. 

Purging may be by either the direct or slug method, and may involve the use of an intermediate inert gas purge. At all stages, the vent point is sampled and the purge is deemed satisfactory when certain criteria are met. 

The chief engineer calls you into his office and asks you to prepare an outline design for an inert gas purging and blanketing system for the reactors and other equipment, on shutdown. This request arises from a report into an explosion and fire at another site manufacturing a similar product. 

Hazards attendant on use of ethylene oxide in steriliser chambers arise from difficulties in its subsequent removal by evacuation procedures, owing to its ready absorption or adsorption by the treated material. Even after 2 evacuation cycles the oxide may still be present. Safety is ensured by using the oxide diluted with up to 90% of Freon or carbon dioxide. If high concentrations of oxide are used, an inert gas purge between cycles is essential [7], The main factors in safe handling... 

Oxygen gas is normally present in electroless solutions unless steps are taken to reduce its concentration by inert gas purging, the concentration of dissolved O2 usually approaches 10 4 mol dm 3 at room temperature. In contrast to deliberately added solution stabilizers, the O2 molecule tends to adsorb weakly on catalytically active surfaces, where it may or may not undergo dissociation [125], Since at many metallic surfaces it is capable of being reduced via either a 2-electron or a 4-electron reaction route, dissolved O2 gas affects the mixed potential of the surface being coated in the electroless solution. Shown here is the case of a 4-electron reduction reaction in basic solution ... 

Monitoring The differential pressure across the arrester element can be monitored to determine the possible need for cleaning. The pressure taps must not create a flame path around the arrester. It can be important to provide temperature sensors such as thermocouples at the arrester to detect flame arrival and stabilization. Since arrester function may involve damage to the arrester, the event of successful function (flame arrival) may be used to initiate inspection of the element for damage. If the piping is such that flame stabilization on the element is a realistic concern, action must be taken immediately upon indication of such stabilization (see also Endurance Bum). Such action may involve valve closure to shut off gas flow or inert gas purging. 

Run the poly(vinyl chloride) in the instrument using an inert gas purge (usually N2.)... 

Fig. 1.22. Solids transfer under an inert atmosphere. (

A platinised alumina catalyst had been treated with flowing hydrogen at ambient temperature. Purging with air caused an explosion. Inert gas purging is essential after treating catalysts or adsorbent with hydrogen before admitting air. 

Figure 8.7 Membrane systems to recover and recycle hydrogen lost with the reactor inert-gas purge stream [6],...

Recovery of hydrogen from the recycle streams of refinery hydrocrackers is a similar application [15,16]. In these units, heavy oil is treated with hydrogen to crack Cg-Ci2 hydrocarbons into C4-C6 molecules, and an inert-gas purge is used to remove... 

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