Feed lines

Because of its antimicrobial activity, acrolein has found use as an agent to control the growth of microbes in process feed lines, thereby controlling the rates of plugging and corrosion (see Wastes, industrial). 

System includes automatic actuation of most activities, with changing of feed lines to silos accomplished by diverter valves controlled automatically by process control computer. 

FIG. 22-42 Four alternative modes of contimioiis-flow operation with a foam-fractionation column (1) The simple mode is illustrated hy the solid lines. (2) Enriching operation employs the dashed reflux line. (3) In stripping operation, the elevated dashed feed line to the foam replaces the solid feed line to the pool. (4) For combined operation, reflux and elevated feed to the foam are both employed. 

Feed lines from a concentrated sulfuric acid storage tank failed. Tubing contained large, ragged holes due to severe internal surface wastage (Fig. 7.21). 

Provide check valve (s) in feed line (secondary control)... 

Provide for automatic/manual closure of isolation valve(s) in feed line on detection of low or no flow... 

Install emergency relief device (ERD) on feed vessel or feed line... 

Eeed through vessel top with antisiphon device in feed line... 

Blockage of liquid Monitor pressure drop across vent system (e.g., effluent line due local indication, alarm or interlock) to closed valves,, Interlock valve in feed line to centrifuge results in flooding of basket and Equipment/line-up checks overflow from Remove unnecessary valves basket to solid col-. 5, lection system in base. Possibility of liquid spill. ... 

Minimizing the starting losses and strain on the feeding lines, as the motor now starts up lightly and accelerates quickly. 

With the availability of more advanced interrupters in future, it will be possible to upgrade the present guidelines and permit connections of more feeding lines on an existing grid without having to resort to a series reactor. 

To establish the minimum fault level, impedances of the feeding lines from the source of supply up to a selected point, at which the fault level is to be determined, must be added. For a step-by-step calculation to arrive at such a fault level refer to lEC 60909 and the literature on the subject as well as the references at the end of this chapter. 

The small volumes of the feed line from the switching valve to the reactor and the discharge line to the analyzer can be corrected for, since they will have plug flow. This will only displace the zero time on the recorder and it can be easily corrected. 

Horizontal natl. circ. Ease of maintenance Lower skirt height than vertical Less pressure drop than vertical Longer tubes possible Less cost than kettle No theoretical tray Extra space and piping as compared to vertical Fouls easier as compared to vertical Accumulation of higher boiling point components in feed line, i.e., temperature may be slightly higher than tower bottom... 

Fluidized-bed catalytic cracking units (FCCUs) are the most common catalytic cracking units. In the fluidized-bed process, oil and oil vapor preheated to 500 to SOOT is contacted with hot catalyst at about 1,300°F either in the reactor itself or in the feed line (called the riser) to the reactor. The catalyst is in a fine, granular form which, when mixed with the vapor, has many of the properties of a fluid. The fluidized catalyst and the reacted hydrocarbon vapor separate mechanically in the reactor and any oil remaining on the catalyst is removed by steam stripping. 

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