Room Operating Variables

No chemical plant can be designed to operate only at its standard process flow diagram conditions. Chlor-alkali plants in particular are subject to a number of perturbations that affect the requirements of the process. 

The operating voltage and current efficiency of a cell fix its unit DC power requirement. This varies with time, usually in the direction of increasing power consumption, and so cells and their auxiliaries must be designed with this fact in mind. In a diaphragm or membrane cell, performance declines over the lifetime of the anolyte/catholyte separator, usually as a result of the accumulation of impurities. The performance of a mercury cell 

The water content of the hydrogen gas is lower because of the presence of caustic in the catholyte or decomposer. Differences among the various types of cells are greater than in the case of chlorine because of the large differences in caustic concentration. 

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It was shown that room-temperature molten salts derived from the combination of 1,3-dialkylimidazolium chloride and A1C13 can be used as solvents in two-phase catalytic dimerization of propene to give hexenes catalyzed by Ni(II) compounds (125). The effects of phosphane ligands coordinated to nickel and operating variables were also investigated (126). The dimerization products separate as an organic layer above the molten salt. This reaction has been carried out with n-butenes as the reactant and cationic nickel complex catalysts dissolved in organochloroaluminate liquids (127). 

To overcome hindsight bias, it is useful to examine exactly what evidence the operators had at time of each decision in the sequence of events. One way to do this is to draw the operator s process model and the values of each of the relevant variables in it. In this case, both operators thought the control valve was closed—the control room operator had closed it and the control panel indicated that it was closed, the flow meter showed no flow, and the outside operator had visually checked and there was no flow. The situation is complicated by the occurrence of other alarms that the operators had to attend to at the same time. 

Sufficient Information should be displayed in the control room to permit the control room operator to take action in the event of an upset or to identify the problem for direct attention of the outside operator. Typical information required includes alarms, variable indication, critical running lights, etc. Location of controllers (local or panel) should be determined by how often the set point of that controller requires attention. Prime candidates for local control are non-critlcal level controllers (condensate flash tanks, surge tanks), tank pressure controllers, non-critical heater temperature controllers, etc. Local indication should be provided for evaluation by the outside operator. 

First, there is a big difference in the information acquisition method on the conditions of the power plants and physical operation variables. Though in conventional MCR the Shift Supervisor (SS) in total charge of the operation can confirm the system conditions and operation variables of the power plants through communication with the Board Operator (BO) as Reactor Operator (RO), Turbine Operator (TO), and Electrical Operator (EO), in the advanced control room the entire operators including the SS can acquire and confirm the entire operation information through the Large Display Panel (LDP) and each operator s monitor. 

CRO An abbreviation for control room operator, this is a person who forms part of a team based primarily in the control room of a process plant. The CRO is responsible for monitoring the screens and displays that present real-time data of the process, as well as taking appropriate action when process variables deviate beyond the expected limits. This is normally brought to the attention of the CRO by flashing displays and audible alarms. 

If it is variable, set the outside air intake quantity to the winter value. Set the desired temperature up to a maximum, leaving the humidity setting alone. It will be appreciated that as the room temperature rises during the heating test the rh tends to fall. However, since the humidity setting remains unaltered the humidifying system will be called upon to operate until at one condition it is working at peak winter rate. Due to the faster characteristic of heaters, the rh will be found to fall but absolute moisture should be found to steadily rise. The duration of the test is normally about 3 h and final conditions should be held for half an hour to prove the moisture source. 

The present description is based on previous publications from this laboratory56-59 and the interested reader will find additional details and references in that work. Two different ion-source reaction chambers are used. One of these sources which operates at room temperature is shown in Figure 4. The second source, a variable temperature source will also be described. The electrospray generator and the ion-source reaction chamber are shown in Figure 4, while the mounting of the ion source and the front end of the mass spectrometer are shown in Figure 5. 

The pressure balance should be examined to determine the normal pressure readings in the reactor, regenerator, air system, flue gas system, and main fractionator and overhead system. These need to be followed on a time basis and plotted against variables such as feed rate, wet gas rate, and dry gas rate to see if and where problems may occur. Adjustments may be possible if the spent or regenerated catalyst slide valve delta P is at a minimum to provide more operating room. 

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