Vapor closed loop

In a typical closed-loop system, liquid from the separator is cooled in a heat exchanger then recirculated. Any excess liquid added by mist and vapor flows out through a level-control valve. ... 

Integrated vapor extraction and steam vacuum stripping can simultaneously treat groundwater and soil contaminated with VOCs. The system developed by AWD Technologies consists of two basic processes a vacuum stripping tower that uses low-pressure steam to treat contaminated ground-water and a soil gas vapor extraction/reinjection process to treat contaminated soil. The two processes form a closed-loop system that provides simultaneous in situ remediation of contaminated groundwater and soil with no air emission. 

Drizo A variation of the glycol process for removing water vapor from natural gas, in which the water is removed from the glycol by stripping with a hydrocarbon solvent, typically a mixture of pentanes and heavier aliphatic hydrocarbons. The process also removes aromatic hydrocarbons. Last traces of water are removed from the triethylene glycol by stripping with toluene in a separate, closed loop. Invented in 1966 by J. C. Arnold, R. L. Pearce, and H. G. Scholten at the Dow Chemical Company. Twenty units were operating in 1990. U.S. Patent 3,349,544. 

Liquid fuel was seldom utilized in the previous ACC studies because it was not only difficult to actuate liquid-fuel injection at high frequencies, but the combustion delays associated with liquid-fuel atomization, droplet heating, vaporization, and burning processes made such a control extremely slow for fast-response in situ type controllers. As a result, the use of liquid fuel was confined to either steady injection process ]13] or upstream addition of prevaporized fuel ]4, 7] which limited the ACC flexibility associated with temporal responsiveness. The goal of this project is to make ACC more practical for propulsion systems by studying direct liquid-fueled ACC in a closed-loop controller setting. 

BioSparge is a closed-loop, in situ and ex situ bioremediation technology that uses vapor extraction, gas injection and biodegradation to remediate contaminant plumes below the ground-water level. This process works by extracting soil vapor from wells placed at the perimeter of... 

Hot water heat exchanger. In this H/Ex., heat contained in some of the refrigerant vapor from the first stage generator is transferred to a two pipe, closed loop, hot water heating circuit. 

Figure 5.18 Closed-loop evolution of (a) the condenser vapor holdup setpoint and (b) the purge flow rate for a 15% increase in the production rate occurring at t = 0, under plant-model parameter mismatch. The reaction rate and the mass-transfer coefficient /Cb in the controller model are assumed to be overestimated by 10% compared with their values in the plant.

The initial equipment costs and operating costs for the more conventional processes are higher than for supercritical carbon dioxide. The higher equipment costs are due to the additional parts needed for environmental treatments (i.e., scrubbers, vapor incinerators, etc.) The consumables costs are lower for the supercritical fluid processes due to the closed-loop recycle design of the supercritical fluid system, elimination of water for rinsing and the reduced electricity costs associated with not having to dry the parts. 

Three steps eliminate these odor problems. The first is a distillate recovery system that recovers most of the fatty acid as a byproduct and many of the associated odors in the deodorizer vapor discharge. The second is a closed-loop cooling system that keeps the fat-laden hot well water out of the cooling tower. The third is a vapor scrubbing or oxidation system to eliminate volatile organic compounds that are not removed in the previous two steps. 

For the hydrocarbon--CO2 systems studied here, at pressures above the critical pressure (7.383 MPa) and above the critical temperature (304.21 K) of C02 the isobaric x,T coexistence plots of liquid and vapor phases form simple closed loops. The minimum occurs at the lower consolute point or the Lower Critical Solution Temperature (LCST). Since pressure is usually uniform in the vicinity of a heat transfer surface, such diagrams serve to display the equilibrium states possible in a heat transfer experiment. 

Hot air that is used to dry pharmaceuticals is recycled in a closed loop to prevent the contamination of the moist material from atmospheric impurities. In the first conditioning step for the air, 5000 k mol/hr at 105 kPa and 42 C with a 90% relative humidity are fed to a condenser to remove some of the water picked up previously in the dryer. The air exists the condenser at 17°C and 100 kPa containing 91 k mol/hr of water vapor. Next, the air is heated in a heat exchanger to 90°C, and then goes to the dryer. By the time the air enters the dryer, the pressure of the stream has dropped to 95 kPa and the temperature is 82 C. 

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