Purge hole

A small hole has been deliberately placed in a vessel near the top to provide a controlled vent for a nitrogen purge/blankeL The hole is 0.2-inch diameter witli the vessel operating at 150 psig at 100°F. Determine the flow through this vent hole. Assume it acts as a sharp edged orifice. 

In cases where wells have a screened or open-hole interval partially submerged below the water table and a pump is going to be used for both purging and sampling, the pump should be placed at the midpoint between the top of the water table and the bottom of the screen. If different equipment is going to be used for purging and sampling of the well, the pump should be placed at the top of the water column. ... 

The homopolymerizations were all run in 28 oz. beverage bottles. The bottles were baked for at least 24 hrs. and then capped with crown, three-hole caps and rubber liners. Cooling of the bottles was effected while purging with nitrogen. After cooling, the bottles were charged with the butadiene blend, the heterogeneous initiator-hexane suspension and modifiers. 

The most inexpensive and simplest system is the glove bag, which is basically a plastic bag open at one end with glove inserts. The materials to be used are placed in the bag in the collapsed condition. Holes are cut in the plastic for making electrical connections and so on, and then sealed with tape or other suitable material. The bag is then purged with inert gas for several minutes and the open end is sealed with the gas continuing to flow. 

Fig. 2.12. Glove bag fitted around a binocular microscope. A hole large enough to fit the eyepiece of the microscope is cut in the top of the glove bag. The glove bag is then fastened to the microscope using electrical tape and purged of atmospheric gases.

The cell consists typically of a 10-20 mL vessel and an electrode holder made of plastic or Teflon with holes for the working (W), reference (R) and counter (C) electrodes. In addition, there is an inlet for an inert gas, usually nitrogen or argon, by which the solution is purged before the measurements are made. Usually also, a gentle stream of the inert gas is maintained over the surface of the solution during the electroanalytical measurements. 

Addition of sodium hydride to a damp reactor which had not been purged with inert gas caused evolution of hydrogen and a violent explosion. Solid dispersions of the hydride in mineral oil are more easily and safely handled [1], When an unprotected polythene bag containing the hydride was moved, some of the powder leaked from a hole, contacted moisture and immediately ignited. Such materials should be kept in tightly closed containers in an isolated, dry location [2]. 

The temperature scale and the cell constant were calibrated using indium. Samples of approximately 4 mg were heated at 20 °C / min over the temperature range of 25-200 °C, under dry nitrogen purging (80 ml /min) in a pin-holed aluminum pan. The melting range of atorvastatin calcium was found to take place over the broad range of 158.4-178.03 °C. 

The thermogravimetric (TG) analysis of atorvastatin calcium, Form-I, is shown in Fig. 1.60, and was performed using a Mettler Toledo 851e TGA/ SDTA system. The samples were contained in pin-holed aluminum crucibles that were heated at a rate of 20 °C/min from 25 to 200 °C under nitrogen purging (10 ml/min). The initial steps observed from 40 to 160 °C correspond to the loss of hydrate water. 

Without a method or mechanism to detect a catastrophic, or even a small release from an inner wall, the use of a secondary outer wall is superfluous. A failure in the inner wall will certainly lead to a failure of the outer wall if the failure goes unnoticed and no action is taken. The secondary wall may delay the release, but release would be inevitable without annular space detection. Typical detection mechanisms include gas analyzers or pressure detectors for vapors, conductivity switches for liquids, or weep holes routed to drain systems that are periodically monitored (Prugh, 1992). A purge gas is sometimes used as a detection medium, to reveal a change in contaminants in the purge gas exhaust (CCPS, 1988b). 

The solution is transferred with a disposable pipet to a 200-mL conical beaker, aided by a few drops of water. The beaker is placed in a nitrogen tilled desiccator. The desiccator lid is fltted with two glass tubes in a two-hole stopper. The nitrogen inlet tube extends to the bottom of the desiccator. The outlet tube is flush with the bottom of the stopper. After purging the desiccator with nitrogen for 15 min, the flow is reduced to one bubble every 2 sec from an oil bubbler. The desiccator is left at room temperature for 1 to 4 weeks. 

Dissolve 80 g FeS04 7 H2O in 560 mL deionized water (previously flushed with N2) in a 1 L glass beaker. The reaction vessel should be closed with an air tight plastic lid containing several holes for inlets and a thermometer (Fig. 11-1). Place the beaker in a water bath (e.g. in a 3 L beaker filled with water at a temperature of 90 °C) and insert the thermometer for temperature control and a gas inlet for purge N2. The reaction... 

Several experimenters have noticed that some of the experimental PEMs on the market recently are quite thin, and that if their systems or fuel cells are not purged, they get what is called in the trade membrane blowout. The oxygen in the system air that was not purged out, and the hydrogen combine in the presence of the catalyst on the membrane, and burn micro holes in the cheaper thinner membranes, resulting in a pop or system failure. 

In operation with diametrically opposed electrodes, the FCC arc column bears directly on the carbon anode which is completely covered by the arc crater at 150 amp or more. The pump valve is opened sufficiently to meter the plasma down through the anode hole, to purge and... 

To reduce an organic substrate which cannot compete efficiently with oxygen for electrons, oxygen must be removed from the system. This is usually accomplished by purging the reaction mixture with nitrogen or argon. In addition, an electron donor, such as an alcohol or an amine, is often used to scavenge the electron holes so the conduction-band electrons are available for the reduction [22,23]. 

---