Discharge coolers

A relatively large quantity of oil is injected into the flow stream to lubricate the vanes. This is normally captured by a discharge cooler and after-scmbber and recycled to the inlet. 

The hydrocarbon liquid is split. Some is pumped back to the main column as reflux and some is pumped forward to the gas plant Condensed water is also split. Some is pumped back as wash to the overhead condensers and some is pumped away to treating. Some might be used as wash to the wet gas compressor discharge coolers,... 

Turn on cooling water to the solvent (LLO) discharge cooler and to the aqueous (HLO) discharge cooler. 

Enthalpv/Entropy Correlations. The most expensive item in a turboexpander plant is the compressor which is designed from enthalpy/ entropy calculations. For a fixed horsepower the results are almost the same for Property-75, Peng-Robinson, GPA K H Soave, GPA K H Lee, GPA K H Starling-Han BWR, and GPA-k method. The largest variation predicted is in the discharge temperature (maximum differences of 6.8° and 5.4°F) which would affect the discharge cooler sizes (assuming 120°F) by 3%. 

Gas injection discharge cooler 11 55,1 Heat exchangers—opiate conventional... 

SL/RN Process. In the SL/RN process (Fig. 4), sized iron ore, coal, and dolomite are fed to the rotary kiln wherein the coal is gasified and the iron ore is reduced. The endothermic heat of reduction and the sensible energy that is required to heat the reactants is provided by combustion of volatiles and carbon monoxide leaving the bed with air introduced into the free space above the bed. The temperature profile in the kiln is controlled by radial air ports in the preheat zone and axial air ports in the reduction zone. Part of the coal is injected through the centerline of the kiln at the discharge end. The hot reduced iron and char is discharged into an indirect rotary dmm cooler. The cooled product is screened and magnetically separated to remove char and ash. 

Fig. 2. Flow sheet of lecithin producing unit. Crude soybean oil is heated in the preheater, 1, to 80°C, mixed with 2% water in the proportion control unit, 2, and intensively agitated in 3. The mixture goes to a dweUing container, 4, and is then centrifuged after a residence time of 2—5 min. The degummed oil flows without further drying to the storage tanks. The lecithin sludge is dried in the thin-film evaporator, 6, at 100°C and 6 kPa (60 mbar) for 1—2 min and is discharged after cooling to 50—60°C in the cooler, 8. 9 and 10 are the condenser and vacuum pump, respectively.

Fig. 12. Unipol PP process where A is the polymerization reactor B, recycle gas compressor C, recycle gas cooler D, product discharge tank E, impact copolymer reactor F, recycle gas compressor G, recycle gas cooler and H, product discharge tank (134).

Vapors (from drying) are removed at the feed end of the dtyer to the atmosphere through a natural-draft stack and settling chamber or wet scrubber. When employed in simple drying operations with 3.5 X 10 to 10 X 10 Pa steam, draft is controlled by a damper to admit only sufficient outside air to sweep moisture from the cylinder, discharging the air at 340 to 365 K and 80 to 90 percent saturation. In this way, shell gas velocities and dusting are minimized. When used for solvent recovery or other processes requiring a sealed system, sweep gas is recirculated throu a scrubber-gas cooler and blower. 

In some cases in which it is desirable to cool the product before removal to the outside atmosphere, the discharge end of the cyhnder is provided with an additional extension, the exterior of which is water-spray-cooled. In cocurrent-flow calciners, hot gases from the interior of the heated portion of the cylinder are withdrawn through a special extraction tube. This tube extends centrally through the cooled section to prevent flow of gas near the cooled-shell surfaces and possible condensation. Frequently a separate cooler is used, isolated from the calciner by an air lock. 

The startup of the production unit was exciting. The extended surface cooler on the discharge end was installed and about half of the design pressure was used to avoid ignition. In spite of this, on the first day an ignition was observed and emergency shut down was activated. Removing the bottom closure it became evident that the square form of the cooler... 

Startup flow to the expander is designed to be supplied from the discharge of the compressor through a throttle valve and cooler. A careful study of the characteristics of the compressor blow-off valve and the expander startup valve was performed by Solvay process engineers. Based on these calculations, the startup cooler and valve were sized to supply the minimum required flow to tlie expander wheel. 

Recalculate the discharge temperature for Section 2, using the previous cooler outlet temperature. 

In order to avoid the need to measure velocity head, the loop piping must be sized to have a velocity pressure less than 5% of the static pressure. Flow conditions at the required overload capacity should be checked for critical pressure drop to ensure that valves are adequately sized. For ease of control, the loop gas cooler is usually placed downstream of the discharge throttle valve. Care should be taken to check that choke flow will not occur in the cooler tubes. Another cause of concern is cooler heat capacity and/or cooling water approach temperature. A check of these items, especially with regard to expected ambient condi-... 

Proper vessel designs should avoid discharges from high-positioned coolers directed down a pipe. This situation reduces pressure in coolers via siphon action. 

For coolers, condensers, steam heaters and reboilers. The effluent cooling water and condensate are typically discharged as follows ... 

We can then add the two cycles together as shown in Fig. 8.4c, to form a semi-closed plant. There is double the flow through this new plant, double the heat supply and double the work output. Strictly, the total heat rejected is not doubled half the turbine exhaust is now discharged to the atmosphere and half the heat rejected into a cooler before it is recirculated into the compressor. The thermal efficiency of this double semi-closed plant is unchanged from that of the original closed cycle and the original open cycle. So there is apparently no thermodynamic advantage in semi-closure it is undertaken for a different purpose. 

Figure 7.4 Microcomputer programming of a hatch cooling crystallizer. A, crystallization vessel, B, control heater, C, control cooler. surrounding the draft-tube), D, contact thermometer, E, discharge plug and conical baffle), F, recorder, G, relay, H, temperature programmer, I, cooling water pump, J, cooling water reservoir, K, water inflow L, water outflow after Jones and Mullin, 1974)...

Screw compressors are rotary positive displacement machines. Two helical rotors are rotated by a senes of timing gears as shown in Figure 10-8 so that gas trapped in the space between them is transported from the suction to the discharge piping. In low-pressure air service, non-lubri-cated screw compressors can deliver a clean, oil-free air. In hydrocarbon service most screw compressors require that liquid be injected to help provide a seal. After-coolers and separators are required to separate the seal oil and recirculate it to suction. 

---