Heat exchangers regenerator vaporizers

Figure 1 indicates the schematic flow of two-bed pyrolysis plant. This plant consists of the pyrolysis reactor and the regenerator through which fluidized medium circulates, the precombustion burner, the raw material feeder, the cyclones, the heat exchangers, the vapor-liquid separator, the gas recycle blower, the air feeder, the gas cleaner and the produced-gas combustion device. The plant also includes various auxiliary equipment, the devices for measuring and recording flow rate, pressure and temperature, as well as the automatic analysis for gas. 

The feed is vaporized by reactor effluent heat-exchange and enters into the dehydration reactor. The dehydration reactor effluent is mixed with preheated recycle gas and enters the conversion reactors. Although Figure 10 shows four parallel or "swing conversion reactors, a lesser or greater number of reactors may be used depending upon the feed rate and regeneration frequency desired. 

Description The feed, either paraffinic or olefinic C -Cg fraction, is heated through heat exchangers and a furnace to the desired temperature. The vaporized feed is fed to the top of the aromatization reactor. There are two reactors in series are in operation, and the other two reactors are in regeneration or standby. The effluent from the bottom of the second reactor is fed to the aromatization feed/effluent heat exchanger. After the feed/effluent heat exchanger, the reactor effluent is further cooled by air coolers and trim coolers with cooling water and chilled water. This cold effluent is then sent to the aromatization effluent separator (low pressure) where the rich net gas stream is separated from the aromatic-rich liquid. 

Solvent is discontinuously removed from the contents of a distillation still (1) by blowing water vapor into the still. The impure vapor is condensed in a steam converter (a tube heat exchanger (2), slightly inclined). The condensate is fed to a regeneration unit for further treatment. Pure steam generated at the jacket during vapor condensation is compressed to the injection pressure in a steam compressor (4) and is simultaneously superheated. The superheat is removed in a saturator (5) by the injection of condensate or water and the saturated steam is injected into the distillation unit (1). 

In the flow diagram shown, steam and solvent vapors discharged from the adsorber being regenerated are condensed in a water-cooled heat exchanger, the condensate is collected in a separate vessel, and the solvent, which is insoluble in water, is decanted and returned to the process. When the solvent is partially or completely soluble in water, a more elaborate separation step is required. This step, which usually includes distillation, must, of course, be designed for the specific separation involved. 

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