Coolers ejectors

Figure 1. A wide range of pressures can be achieved by using various combinations of ejectors and condensers. The same steam consumption is used for each design here. Note Curves are based on 85°F condensing water. If warmer water is used, curves shift to the left—cooler water, shift right.

Figure 6-32 illustrates ejector systems with large condensable loads which can be at least partially handled in the precondenser. Controls are used to maintain constant suction pressure at varying loads (air bleed), or to reduce the required cooling water at low process loads or low water temperatures [2]. The cooler W ater must not be throttled below the minimum (usually 30%-50% of maximum) for proper contact in the condenser. It may be controlled by tailwater temperature, or by the absolute pressure. 

Low-pressure injection between air ejectors and drain coolers... 

The vapors leaving the primary barometric condenser proceed to a steam ejector that is followed by another barometric. Pressures at the tops of the towers are maintained at 50mmHg absolute. Pressure drop is 2mmHg per tray. Bottom temperatures of the three towers are 450, 500, and 540°F, respectively. Tower overhead temperatures are 200°F. Pitch and roan go to storage at 350°F and the other products at 125°F. The steam generated in the pitch and rosin coolers is at 20 psig. Process steam is at 150 psig. 

From the granulating screw (5) the granulated product is fed to an ejector, whence it is transferred by the air flow created by a fan to a cycline separator (6), in which the granulated material is separated from the dust-air mixture. The dust is passed to the filters and the granules are fed to a spiral oscillating conveyer (cooler) (7). 

The daily output of a cooler measuring 1650 X 610 X 350 mm and an absorber measuring 1650 X 970 X 350 mm equals 7.5 tons of 30 to 35 per cent hydrochloric acid. As a rule, two graphite absorbers are connected in series and the more diluted acid from the second absorber which contains about 20 per cent HC1 is pumped into the first absorber. The rest of the unabsorbed gas is led through a rubber lined steel absorption tower into the atmosphere. The tower is sprayed with water and the diluted acid obtained is employed as an absorption liquid in the second igurite absorber. The flow of the tail gases is aided by a steam-jet ejector. 

Simprosys 3.0 contains 20 unit operation modules and 2 utilities as displayed in Figure 60.2. The 20 unit operation modules include solid dryer, liquid dryer, burner, cyclone, air filter, bag filter, electrostatic precipitator, wet scrubber, scrubber condenser, fan/blower, compressor, steam jet ejector, pump, valve, heater, cooler, heat exchanger that can also be used as an evaporator, liquid-vapor separator. 

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