Process water system

In particular, it accommodates desalting water, drainings from crude tanks and neutralization water from alkylation tanks. Boiler blowdown and sweetening brines are discharged downstream from the process water system, whose average throughput is 30 to 60 m -h , Treatment (see Fig. 62) comprises three main steps after some effluents are cooled down  

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Acrolein at a concentration of <500 ppm is also used to protect Hquid fuels against microorganisms. The dialkyl acetals of acrolein are also useful in this apphcation. In addition, the growth of algae, aquatic weeds, and moUusks in recirculating process water systems is also controlled by acrolein. 

Bums and Hazzan demonstrated tlie use of event tree and fault tree analysis in tlie study of a potential accident sequence leading to a toxic vapor release at an industrial chemical process plant. The initiator of tlie accident sequence studied is event P, the failure of a plant programmable automatic controller. Tliis event, in conjunction willi the success or failure of a process water system (a glycol cooling system) mid an operator-manual shutdown of tlie distillation system produced minor, moderate, or major release of toxic material as indicated in Fig. 21.4.1. The symbols W, G, O represent tlie events listed ... 

W failure of process water system G. failure of glycol cooling system... 

GPWMVB/GPWMVA GC compressors B/A process water system (PW) supply manual valve closed... 

Identification and selection of the separate wastewater treatment steps required for constituting a complete wastewater treatment and process water system. 

Carton, F. J., Agalloco, J. P., Artiss, D. H. Validation of Aseptic Pharmaceutical Process. Water System Validation. New York Marcel Dekker (1996). 

Acidity. For many years the pH of the paper has been considered an important characteristic affecting peramnence. Permanency specifications exist which call for paper with a pH of 6.5 or higher. Other specifications say that the pH should not be lower than 5.5. There is no disagreement, however, about the poor permanency of paper when it is under pH 5.5 (4). In this context, paper pH is determined by the extraction procedure already described. The acidity that is present in the paper will promote acid hydrolysis of the glucosidic bonds of cellulose. To prevent this type of degradation and to produce paper with a high extract pH, the paper machine process water system must be controlled at a neutral to alkaline pH with a minimum of total acidity, preferably with an excess of alkalinity. The term total acidity is used to describe the concentration of all dissolved ions and particles in the process water that contribute to acidity in the system and a low extract pH in the paper. For example, papermaker s alum dissociates to alumi-... 

The consequences of the accident were exacerbated by the lack of a water system dedicated to fire fighting, and by deficiencies in the shared system. When the process water system was extensively damaged by the explosion, the plant s water supply for fighting fires was also disrupted. The water pressure was inadequate for fire fighting. The force of the explosion ruptured water-lines and adjacent vessels containing flammable and combustible materials. The ruptured water lines could not be isolated to restore water pressure because the valves to do so were engulfed in flames. Of the three backup diesel pumps, one had been taken out of service and was unavailable, and another soon ran... 

B. Drainage System Upgrade Install above-grade, pressurized sewers, segregating stormwater and process water systems. 

Finally, we discuss an example of designing a heat recovery system for the process water system of a paper mill (see Fig. 6.5). The problem involving four objective functions has been described and solved in Hakanen et al. (2005, 2006). We consider a virtual fine paper mill operating in a climate t3q)ical to northern latitudes, where ambient temperature varies according to the season. 

The aim is to organize the heat management of the process water system in the most efficient way. A special characteristic of this optimization... 

Fig. 6.5. A simplified flowchart of the heat recovery for the process water system of a paper mill.

Figure 8.6 Integrated circuit process water system. (Bell Laboratories, Murray Hill, NJ)...

During 1947 a design of the process—water system was conceived and developed for construction of the MTF at Oak Ridge National Laboratory. In the middle of 1949 the U. S. Navy Proving Ground in the Snake River Plains of Idaho was chosen as the Reactor Testing Station. With these fundamental data available, the design was redeveloped to suit the Idaho locality. 

General Description of the system. Figure 7.2.A. schematic diagram of the MTR process—water system, presents.an overall picture of all the vessels, pumps, pipe lines, and auxiliary equipment involved in the MTR proc-ess— Water system ... 

Stand-by and Energency Features. Certain provisions are made to ensure satisfactory operation of the process-water system under emergency conditions. The primary requirement in emergencies is that there always be some water flow through the reactor. 

A flow recorder is provided on the water lines from each experimental plug, and,unless the flO through the plugs is satisfactory, the reactor cannot be-started. A water meter is provided in the line- supplying demineralized water to the rabbits and experimental plugs-so- that an inventory may be kept on the amount of water introduced into- the process-water system in this manner ... 

The only possible cause of water hammer in the process-.water system would be an instantaneous closing of the 24-in. main proceS s-water-control valve. If this valve, closed in less than 0.2 sec, the maximum possible increase in pressure. .would be 385 psi if the closing time were 16 sec, the maximum pressure.would be 4 psi. However, since the Valve is designed to close in 30 sec, the. possibility of water hammer is eliminated. Failure of the pumps lifting water to the working reservoir will not cause water hammer because the reverse momentum of the water is quite low. 

The gas solubilites of the water under the conditions that qxist in the demineralizer tank and upo-n, entering the process-water system are as follows ... 

Any constituents in the water that, would. act as catslysts. in the corrosion Of aluininutn, beryllium, or stainless, steel..parts of the process-water system would also be undesirable. For this, reason it is necessary to minimize the amounts of lead, nickel, copper, and chlorides in the water. Ah additional advantage of a low mineral content in the water is that the amount of radioactivity induced in the water is appreciably reduced, thus reducing shielding requirements of the system. 

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