Secondary Cooler

This cooling water is usually arranged in a closed loop with the water being pumped through secondary coolers or over cooling towers and then returned to the jackets for reuse. Water quality must be good, with steam condensate being preferred, properly treated to prevent corrosion, etc. 

Secondary cooler Cool reaction gases prior to absorption. 

Secondary Cooler The secondary cooler takes the exit gases from the oxidation unit at 140°C and cools them down to 65°C, a suitable temperature for entry into the absorption column. It is a shell and tube-type heat exchanger constructed of SS304L. The cooling medium is circulating warm water from the warm-water loop. The inlet temperature is 50°C and the exit temperature is about 80°C. The design pressure for this unit is about 1200 kPa. 

Secondary cooler heat-transfer area = 140m2. 

Application — Secondary cooler Heat-exchange area = 140 m2 Base cost = US 20 775 Design-type factor = 0.65 Design pressure factor = 1.55 Materials factor = 2.4 (for SS304L) US cost = US 50 600... 

The ammonia vaporizer receives liquid ammonia from the adjacent plant at - 15°C and 1240 kPa and vaporizes it at 35°C using warm water. The warm-water loop circulates water from the ammonia vaporizer to the secondary cooler. Water enters the ammonia vaporizer at 80°C and exits at about 50°C. 

The composition of the exit reaction gas from the secondary cooler is calculated as before. 

The secondary-cooler outlet reaction-gas temperature = T,n - [(Cp Fww (Tout - Tin))/(Cp FToi)]... 

Titanium tetrachloride can also be purified from impurities by the continuous technique. The installation for continuous purification consists of several vertical pipe coolers. Liquid products of the reaction are sent into the first cooler, which is located a little higher than the rest, where the mixture is cooled at agitation to -3 - -5°C. After that, the mixture is abruptly cooled to -20 - -23.5 °C the solution deposits crystals of Si2Cl6 and VOCI3. The deposited crystals remain in the primary cooler, and the solution self-flows into the secondary coolers, where it is gradually cooled from -23 to -27 °C titanium tetrachloride deposits as white sediment. It is collected in the secondary coolers and washed with water. The TiCl4 thus purified is 99.92% pure. 

Coke-oven gas flora the exhauster, at a tenqterature of 45 -55 C (113 -131 F), is cooled in the secondary cooler to about 28 C (82°F)> then enters the absorption section of the vessel. A portion of the rich solution from the absorber is cooled and recycled over the bottom packed section to remove the heat of reaction and provide a high liquid flow rate in this zone. Cooled excess flushing liquor, which is a dilute solution of ammonia, is fed into the column in the lower third of the vessel. Water flora the free ammonia stripper is fed into the top of the absorber. This water still contains fixed ammonia, but since this form of ammonia has a negligible ammonia vapor pressure, it does not significantly affect the gas purity attainable. According to Svoboda and Diemer (1990), this type of washer typically reduces the ammonia content of coke-oven gas fiom 200-500 g/100 scf to 2-7 g/100 scf. 

Tubes having a wide range of bore sizes are required to operate at pressures in the region of 150—300 MPa (22—44,000 psi). SmaU bore tubes, say 3—15 mm dia, are used to supply lubricant to the packing cups of secondary compressors, initiator to reactors, etc, while larger bore tubes, say 25—75 mm bore dia, are used to connect compressors to reactors and for the constmction of coolers and tubular reactors. 

Recycle and Polymer Collection. Due to the incomplete conversion of monomer to polymer, it is necessary to incorporate a system for the recovery and recycling of the unreacted monomer. Both tubular and autoclave reactors have similar recycle systems (Fig. 1). The high pressure separator partitions most of the polymers from the unreacted monomer. The separator overhead stream, composed of monomer and a trace of low molecular weight polymer, enters a series of coolers and separators where both the reaction heat and waxy polymers are removed. Subsequendy, this stream is combined with fresh as well as recycled monomers from the low pressure separator together they supply feed to the secondary compressor. 

In spite of low copper contents, massive horizontal development renders porphyry deposits amenable to large-scale production methods. Porphyry deposits are associated with igneous activity and intmsion of molten rocks into cooler parts of the earth s cmst, often in connection with the formation of mountains. Erosion of mountainous areas exposes these deposits to weathering, and, under the right conditions, enables the formation of oxidized or secondary copper deposits. Copper mines in the United States are Usted in Table 2. 

N2 passes through the absorber unchanged, so the N2 in the tail gases = the N2 entering the absorber from the cooler-condenser and the secondary air. Hence ... 

Note the acid from the cooler-condenser could be added to the acid flow in the absorber, on the appropriate tray, to produce a more concentrated final acid. The secondary air flow is often passed through the acid mixer to strip out dissolved NO. 

The secondary air from the compressor must be cooled before mixing with the process gas stream at the absorber inlet to keep the absorber inlet temperature as low as possible. Take the outlet temperature as the same as exit gases from the cooler condenser, 40°C. 

Sensible heat in inlet gases from cooler-condenser = 0.15 GJ/h Sensible heat in secondary air = 1754.8 x 1.0(40 — 25) = 0.018 GJ/h Sensible heat in tail gases (at datum) = 0 Sensible heat in water feed (at datum) = 0... 

In order for a fire to propagate from the product first ignited to another one, two conditions are necessary. Firstly, sufficient heat needs to be released to cause secondary ignition. Secondly, the heat release needs to occur sufficiently fast so that the heat is not quenched in the cooler air surrounding the latter product. 

Quench elbow and secondary scrubber. This system is used to remove acid gases formed from the catalytic oxidation of halogenated organic compounds. The operation of the secondary scrubber is identical to that of the primary scrubber with the exception of a recirculation cooler that maintains scrubber exit gas temperature at 120°F. The secondary scrubber has a constant liquid blowdown that is collected in holding tanks and tested for agent prior to release. 

Cooling water flow to the barrel jacket coolers for the secondary extruder removes the excess energy in the resin dissipated by the primary extruder and also the energy dissipated by the screw in the secondary machine. For a properly designed line, the performance of the secondary extruder determines the overall rate of the process. 

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