Recycle continuous-flow schematic

Figure 1. Flow schematic of a spray-tower adsorber. The scrubbing solution is contacted with hot flue gas, collected in the bottom, and continuously recycled and contacted. Suspended solids and pH of liquid in the recycle loop of Plant D spray towers ranged from 5.2 to 8.7%, and from 5.2 to 6.80%, respectively.

A schematic flow diagram of this process is presented in Figure 12 which depicts three catalyst beds operating in series. Fresh make-up gas is mixed with total recycle and fed to the first bed. The effluent from the first bed is partially cooled so that when it is combined with another portion of cold make-up, the mixture is at or above the initiating reaction temperature. The mixture is fed to the second bed. This procedure is continued to the third and subsequent beds. 

A recycle reactor is a mathematical model describing a steady plug-flow reactor where a portion of the outlet is recycled to the Met, as shown schematically in Figure 9.5. Although this reactor configuration is rarely used in practice, the recycle reactor model enables us to examine the effect of mixing on the operations of continuous reactors. In some cases, the recycle reactor is one element of a complex reactor model. Below, we analyze the operation of a recycle reactor wifii multiple chemical reactions, derive its design equations, and discuss how to solve fiiem. 

An endothermic continuous stirred tank reactor (CSTR) is shown schematically in Figure 15.2. The symbols used in the control schematics are listed in Table 15.1 The controlled variable is the temperature of the product leaving the reactor, and the manipulated variable is the flow rate of steam to the heat exchanger, which adds heat to the recycle line. The final control element is the control valve and associated equipment on the steam hue. The sensor is a temperature sensor/trans-mitter that measures the temperature of the product stream leaving the reactor. The controller compares the measured value of the product temperature with its desired temperature (setpoint) and makes changes to the control valve on the steam to the heat exchanger. The process is the... 

The test unit used operates with four modules aligned in parallel. The filtration unit is approximately 13 feet long, 5 feet wide, and 7 feet high and contains an estimated total membrane area of up to 300 square feet. Automatic level controls provide for unattended operation with continuous feed to the tank. Concentrate recycle flow also can be controlled automatically. Figure 2 provides a schematic of the filtration unit. 

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