Water cycle diagrams

Figure 7 shows a typical cycle diagram for a 200-gallon-per-day distilling unit operating on city water. 

The actual amount of water on earth is relatively constant, but its location and purity may vary. Water moves throughout the environment by what is called the water cycle, or the hydrologic cycle. Figure 19-1 diagrams this cycle. 

A flow diagram for the system is shown in Figure 5. Feed gas is dried, and ammonia and sulfur compounds are removed to prevent the irreversible buildup of insoluble salts in the system. Water and soHds formed by trace ammonia and sulfur compounds are removed in the solvent maintenance section (96). The pretreated carbon monoxide feed gas enters the absorber where it is selectively absorbed by a countercurrent flow of solvent to form a carbon monoxide complex with the active copper salt. The carbon monoxide-rich solution flows from the bottom of the absorber to a flash vessel where physically absorbed gas species such as hydrogen, nitrogen, and methane are removed. The solution is then sent to the stripper where the carbon monoxide is released from the complex by heating and pressure reduction to about 0.15 MPa (1.5 atm). The solvent is stripped of residual carbon monoxide, heat-exchanged with the stripper feed, and pumped to the top of the absorber to complete the cycle. 

The diagram in Fig. 11-101 presents enthalpy data for LiBr-water solutions. It is needed for the thermal calculation of the cycle. Enthalpies for water and water vapor can be determined from the table or properties of water. The data in Fig. 11-101 are apphcable to saturated or subcooled solutions and are based on a zero enthalpy of liquid water at 0°C and a zero enthalpy of solid LiBr at 25°C. Since... 

Example 2 Yield from Evaporative Cooling Starting with 1000 lb of water in a solution at H on the solubility diagram in Fig. 18-57, calculate the yield on evaporative cooling and concentrate the solution back to point H so the cycle can be repeated, indicating the amount of NaCl precipitated and the evaporation and dilution required at the different steps in the process. 

Fig. 6.2 shows a simplified diagram of the basic STIG plant with steam injection S per unit air flow into the combustion chamber the state points are numbered. Lloyd 2 presented a simple analysis for such a STIG plant based on heat input, work output and heat rejected (as though it were a closed cycle air and water/steam plant, with external heat supplied instead of combustion and the exhaust steam and air restored to their entry conditions by heat rejection). His analysis is adapted here to deal with an open cycle plant with a fuel input/to the combustion chamber per unit air flow, at ambient temperature To, i.e. a fuel enthalpy flux of/7i,o. For the combustion chamber, we may write... 

Before eonsidering the effects of water injection in an EGT type plant, it is worthwhile to refer to the earlier studies on the performanee of some dry recuperative cycles. Fig. 6.6 shows the T..s diagram of a [CBT i X r cyele, with a heat exchanger effectiveness of unity. It is implied that the surface area for heat transfer is very large, so that the outlet temperature on the cold side is the same as the inlet temperature on the hot side. However, due to the higher specific heat of the hot gas, its outlet temperature is higher than the inlet temperature of the cold air. 

Robert Horton, an influential pioneer in the field of hydrology, developed one of the first comprehensive representations of the hydrologic cycle in 1931. His original diagram. Fig. 6-4, illustrates the processes by which water moves between the Earth s hydrologic reservoirs. Hydrologic fluxes can be summed up in four... 

Targeting in time interval (5.5-6 h) is shown in Fig. 12.24a. The associated block diagram is depicted in Fig. 12.24b. Since no contaminant load is removed from the B wash, dispensing with used water as effluent would certainly amount to inefficient use of available mass transfer driving forces in the system, as this water could still be reused in the next batch cycles if not reusable in the subsequent time intervals within... 

In-well aeration is the process of injecting air into the lower portion of a dual-screened well with perforations at the bottom and above the water table. As the bubbles rise, they expand, which causes the mixed mass of air and water to have less density. The result is an air-lift pump effect. When the water rises and exits the upper perforations, replacement water enters the bottom of the well. The result is a circulation cycle. Free air does not enter the aquifer, but dissolved air (and oxygen) travels with the circulating water. Figure 9.4 is a schematic diagram of in-well aeration. 

In order to achieve the isothermal heat addition and isothermal heat rejection processes, the Carnot simple vapor cycle must operate inside the vapor dome. The T-S diagram of a Carnot cycle operating inside the vapor dome is shown in Fig. 2.2. Saturated water at state 2 is evaporated isothermally to state 3, where it is saturated vapor. The steam enters a turbine at state 3 and expands isentropically, producing work, until state 4 is reached. The vapor-liquid mixture would then be partially condensed isothermally until state 1 is reached. At state 1, a pump would isentropically compress the vapor-liquid mixture to state 2. 

Plot the sensitivity diagram of cycle efficiency versus open feed-water heater temperature. 

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