Purging operations

More difficult to purge Operating vapors more difficult to purge from the system than random packings and trays. This poses potential fire, explosion, and toxic hazard. 

CLOSE VIO) before (PURGE OPERATIONS) before (OPEN V24)... 

Ordering-2 (AO-3) before (PURGE OPERATIONS) before (AO-4). Ordering-3 => (AO-5) before (AO-6) before (AO-4). 

Fusillo, R. H., and Powers, G. J., Computer aided planning of purge operations. AIChE J. 34, 558 (1988b). 

The purging cycles for an evacuate-first purge are shown in Figure 7-4. In this case the beginning of the cycle is defined as the end of the initial evacuation. The oxygen mole fraction at this point is the same as the initial mole fraction. Furthermore, the remaining cycles are identical to the vacuum purge operation and Equation 7-6 is directly applicable. However, the number of cycles / is the number of cycles after the initial evacuation. 

The oxygen from the dual gas regulator module flows directly through two ports into a closed-end manifold in the fuel cell stack to provide optimum oxygen distribution in the cells. All the oxygen that flows into the stack is consumed, except during purge operations. 

There was no accumulation of metals in either the anolyte or catholyte circuits when a spike of metals was fed with the M28 propellant to simulate particles from antiresonance rods. AEA attributes this success to the use of the catholyte-to-anolyte recycle and the anolyte purge operation. Lead, present in M28 propellant as lead stearate (approximately 0.5 weight percent), was oxidized to lead oxide (Pb02) and did not accumulate in solution. Lead oxide was found on the electrode surfaces and as a deposit in the bottom of the cell cavities (AEA, 2001d). A demonstration test successfully removed the lead oxide using an offline formic acid wash of the cell electrode cavities. This is the planned approach for removing accumulating lead oxide. No lead material balance was provided. 

The purging operation was performed within the design pressure rating of the injection system. However, the mechanical condition (worn threads) of the filter pot and end cap was insufficient to contain the applied air pressure. 

A typical AHU fitted with a purging system is presented in Figure 10.6. The additional equipment includes an axial fan, air-duct connections, and motorized shutoff dampers and a control system which is part of the building automation system (BAS). Before each purging operation, the fresh air and purging dampers would be opened and the return air damper would be shut The AH U and the purging... 

Other Cleaning, Washing, Steaming, and Purging Operations... 

The hazards associated with liquid hydrogen are fire, explosion, and exposure to extreme cold temperatures. The elimination of sources of ignition minimize fire hazards. Careful purge operations performed by drivers using helium eliminate the formation of explosive mixtures during the start-up and shutdown of transfer operations. 

For purging operations, use nitrogen cylinders. These have a CGA 580 valve and fit a CGA 580 nipple and nut connector on the regulator. 

Fig. 6.15 Individual cell voltage acquisition during one single purge operation for the experiment of Fig. 6.11...

A detail of individual cell voltage acquisition during one single purge operation is reported in Fig. 6.15, which refers to the purge peak at about 1870 s corresponding to the stack power of 2 kW (Fig. 6.14). 

Keywords Flaring, Flare Reduction, LNG trains. Purge, Operations, Oil and Gas, Engineering Projects... 

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