Purge lines

A typical arrangement for a voltammetric electrochemical cell is shown in Figure 11.28. Besides the working, reference, and auxiliary electrodes, the cell also includes a N2 purge line for removing dissolved O2 and an optional stir bar. Electrochemical cells are available in a variety of sizes, allowing for the analysis of solution volumes ranging from more than 100 mL to as small as 50 )+L. 

The cell head is fabricated from a 2.54-cm steel plate and has separate compartments for fluorine and hydrogen. The oudet-gas manifolds, hydrogen fluoride feed and purge lines, and electrical connections are on top of the head. The gas separation skirt is made of Monel. An insulating gasket maintains the seal between the tank and the head. The anode assembly consists of 32 carbon blades bolted onto a copper bar, each of which contains three copper conductor posts. The cathode assembly consists of three vertical, 0.6-cm parallel steep plates. The plates surround the anode assembly and are supported by three steel posts which also serve as conductors. 

Blowing down Verify flow path before starting the flow. lines for cleaning., Blow (purge) lines to safe location which protects the operator and environment Wear proper personal protective equipment (PPE) Follow proper sampling procedures Use safe blow-down design CCPS G-22 CCPS G-23 CCPS G-29... 

One means of overcoming this problem is to install a condensate controller, which maintains a positive pressure differential across all the tubes (Fig. I). A condensate controller provides a specialized purge line, which assures a positive flow through the coil at all times. 

Vent and purge lines Operation omitted (08) Operation incomplete (09) Lines not fully purged 4.2.4 Failure of operator to detect pressure in lines could lead to leak when tanker connections broken... 

Vent and purge lines Procedure to indicate how to check if fully purged Ensure training covers symptoms of pressure in line Line pressure indicator at controls. Interlock device on line pressure. 

Manual bleeder valve Argon purge line... 

Figure 6.11. Vented septum injector. Any gas coming in contact with the septum is vented out the septum purge line.

Fig. 2.4. Arrangement of purge lines, (a) For the main box the lower manifold should be the inlet with a dense gas (for instance, Ar) and the outlet with a light gas (for instance, He). (b) A purge-gas manifold in the transfer port equipped with outlet jets to flush volumetric equipment.

Fig. 2.6. Schematic representation of a dry-box purification scheme. (A) Glove box (B) tank argon (C) purge line for pump container (D) gastight pump container (E), 2.7 ft /min graphite ring pump (F) bubbler (G) purification train consisting of Linde 13X and 4A Molecular Sieves, and Vermiculite-supported MnO at room temperature (see Chapter 3). In some installations an additional drying column follows the MnO column. Approximate column dimensions are 3-in. diameter by 4-ft length. (Unpublished design of T. L. Brown.)...

Feed gas is supplied in pulses of up to about a second in length from a compressor and a surge tank. The pulse is controlled by a solenoid valve and a timer. During this feed pulse the exhaust solenoid valve is closed. Following the feed pulse both valves at the feed end are closed for about 0.5 to three seconds this period is called the delay. Finally the solenoid valve on the exhaust or purge line opens for a period of about five to 20 seconds. Since the pressure in this line is maintained below that in the feed line, a reverse flow of gas from the bed occurs. 

Purge line A with water and line B with MeOH. Dial-a-mix 70% MeOH and equilibrate the C18 column at l.OmL/min. When stable, inject 15pL of the seven-component test mixture and annotate the chromatogram s start. Run an isocratic chromatogram. 

Perform wet prime to purge line with the new solvents when changing the solvent reservoirs. 

Addition of a purge line, which is particularly important when reactive gases, e. g., metal halides, acids, and elemental halogens, are used. 

Two nitrogen purge lines were installed on each side of the measurement location to prevent dust buildup. One provides a continuous flow to the module window and probe and the other provides a high flow purge to the probe automatically every 30 minutes. 

SPILL CLEAN-UP stop flow of gas if possible large releases may require down wind evacuation if leak in user s system, close valve, vent and purge lines with inert gas before repairs increase ventilation. 

Most of the process control instruments are connected to the radioactive equipment via air purge lines which are positioned higher than the prdcess vessel to avoid entrance of radioactive solutions into the purge lines. Both density and liquid level are determined by differential pressure between two air probes. 

Simplified versions of the Fig. 5.8d arrangement are common some are described elsewhere (68). In some cases, the purge lines split downstream of a shared rotameter and needle valve. An even simpler system replaces the pressure regulator, rotameters, and needle valves by a restriction orifice in each line. Although the simplified systems save capital and can be made to work, the simplifications are achieved at the expense of more troublesome operation, and the author would not recommend them. 

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