High Level Reactor Operating Range

In damage to the affluent piping system If left uncheclced  

Automatic safety circuit action shall be required of this range. There shall be good geometric coverage of the process by protective Instrumentation. 

Fixed level and/or percentage level trips shall be provided to annunciate and scram the reactor for power levels above a certain level. 

A system response tlme) of 8 seconds maximum shall be permitted for good geometric protection of a reactor divided Into l6 zones or more having a fixed level trip. A system response tlme of k seconds maximum shall be permitted for geometric protection of a reactor divided into two, four or nine zones having percentage trips. 

A high level system may be used with an 8 second or less time response ll with fixed level trips, if it has l6 or 

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To improve unit performance, the existing reactor internals were replaced by high performance vortex t) e mixing chambers to optimize liquid-liquid mixing and VLT distribution trays to increase the number of drip points and minimize the dead flow zones adjacent to the reactor wall (Figure 6). The VLT distribution trays also offered low sensitivity to tray levelness and improved stability over a wide operating range. 

Careful attention to such detail is necessary as a second line of defence against the effects of reactive hazards. The level of protection considered necessary may range from the essential and absolute minimum of effective eye protection, via the safety screen, fume cupboard or enclosed reactor, up to the ultimate of a remotely controlled and blast-resistant isolation cell (usually for high-pressure operations). In the absence of facilities appropriate to the assessed level of hazard, operations must be deferred until such facilities are available. 

The output of each power range channel is directly proportional to reactor power and typically covers a range from 0% to 125% of full power, but varies with each reactor. The output of each channel is displayed on a meter in terms of power level in percent of full rated power. The gain of each instrument is adjustable which provides a means for calibrating the output. This adjustment is normally determined by using a plant heat balance. Protective actions may be initiated by high power level on any two channels this is termed coincidence operation. 

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