Refinery cooling

Chromate versus Non-Chrome Treatment of Refinery Cooling Tower Effluents... 

Water Management Trends in Refinery Cooling Systems (Including the Economics of Cooling Tower Recycle Systems)... 

Wastewater Recycled for Use in (Mobil Oil Corp. s East Chicago, Ind.) Refinery Cooling Towers... 

Oil leaks typically require the use of demulsifiers, defoamers, and temporary oil-skimming equipment. Also, heavy chlorination and the use of nonoxidizers effective against SRBs are recommended. Chlorination usually requires the pH to be reduced to 6.5 to 7.0. Add chlorine to provide 1.0 to 2.0 ppm free CI2 for 4 to 6 hours. Also, add 100 to 200 ppm nonionic surfactant 1 to 5 ppm defoamer may be required. All attempts should be made to reduce oil contamination to an absolute minimum. Even in oil refinery cooling systems, where the risk of periodic oil leaks is high, free oil should never exceed 5 ppm. 

An existing refinery cooling water system was to be expanded. There was a choice between once-through and re-use water, but the selection affected process cooler design and process operating conditions. An itemized check list was made to assist in the choice between the two cooling water systems. 

One thing my pool and process cooling water towers have in common is sludge. Perhaps you have driven past a refinery cooling tower with frothy, white foam billowing from its top. That s caused... 

If the cooling water system has insufficient spare capacity for the design, air[Pg.97]

In the older method, still used in some CIS and East European tar refineries, the naphthalene oil is cooled to ambient temperatures in pans, the residual oil is separated from the crystals, and the cmde drained naphthalene is macerated and centrifuged. The so-called whizzed naphthalene crystallizes at ca 72—76°C. This product is subjected to 35 MPa (350 atm) at 60—70°C for several minutes in a mechanical press. The lower melting layers of the crystals ate expressed as Hquid, giving a product crystallizing at 78—78.5°C (95.5—96.5% pure). This grade, satisfactory for oxidation to phthaHc anhydride, is referred to as hot-pressed or phthaHc-grade naphthalene. 

In oil and gas refinery appHcations, titanium is used as protection in environments of H2S, SO2, CO2, NH, caustic solutions, steam, and cooling water. It is used in heat-exchanger condensers for the fractional condensation of cmde hydrocarbons, NH, propane, and desulfurization products using seawater or brackish water for cooling. 

Carbon steel and alloy combinations appear in Table 11-12 Alloys in chemical- and petrochemical-plant sei vice in approximate order of use are stainless-steel series 300, nickel. Monel, copper alloy, aluminum, Inconel, stainless-steel series 400, and other alloys. In petroleum-refinery sei vice the frequency order shifts, with copper alloy (for water-cooled units) in first place and low-alloy steel in second place. In some segments of the petroleum industiy copper alloy, stainless series 400, low-alloy steel, and aluminum are becoming the most commonly used alloys. 

Inert gas-filled motors can also be used in refineries and chemical plants, but their applications are limited. They have tightly fitted covers and oil seals around the shaft to minimize gas leakage, are continually pressurized with an inert gas or instrument air, and are equipped with an internal air-to-water heat exchanger. Inert gas-filled motors are suitable for any hazardous location but require auxiliaries such as cooling water, gas pressurizing system, and control accessories. 

One of the most important operations in a refinery is the initial distillation of the crude oil into its various boiling point fractions. Distillation involves the heating, vaporization, fractionation, condensation, and cooling of feedstocks. This subsection discusses the atmospheric and vacuum distillation processes which when used in sequence result in lower costs and higher efficiencies. This subsection also discusses the important first step of desalting the crude oil prior to distillation. 

Most refinery process units and equipment are manifolded into a collection unit, called the blowdown system. Blowdown systems provide for the safe handling and disposal of liquids and gases that are either automatically vented from the process units through pressure relief valves, or that are manually drawn from units. Recirculated process streams and cooling water streams are often manually purged to prevent the continued buildup of contaminants in the stream. Part or all of the contents of equipment can also be purged to the blowdown system prior to shutdown before normal or emergency shutdowns. 

Now let us consider utility failure as a cause of overpressure. Failure of the utility supphes (e.g., electric power, cooling water, steam, instrument air or instrument power, or fuel) to refinery plant facihties wiU in many instances result in emergency conditions with potential for overpressuring equipment. Although utility supply systems are designed for reliability by the appropriate selection of multiple generation and distribution systems, spare equipment, backup systems, etc., the possibility of failure still remains. Possible failure mechanisms of each utility must, therefore, be examined and evaluated to determine the associated requirements for overpressure protection. The basic rules for these considerations are as follows ... 

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