Emergency heating systems

Emergency heating systems when a material could either freeze or become viscous, which would plug lines and prevent movement into a mitigation system. 

Safety Systems. A safety system is provided with built in safety shutdowns and emergency stop buttons. Crash buttons are located in the laser room, the laser table enclosure and the dome. The laser system is tied into the Observatory emergency stop system. Included both in the laser room and on the laser table are surveillance cameras, heat exchangers, alcohol sensors and fire detectors. In addition to personnel safety features, extensive interlocks have been installed in the laser to prevent the operator from inadvertently damaging it. 

Provision of emergency cooling systems for reactors, where heat continues to be generated after shut-down for instance, in some polymerisation systems. 

Fauske, H. K., M. A. Grolmes, and J. C. Leung, "Multi-Phase Flow Considerations in Siting Emergency Relief Systems for Runaway Chemical Reactions," Multi-Phase Flow and Heat Transfer III-B, Applications, 899 (1984), Elsevier, Amsterdam, The Netherlands. 

This is the example from the previous chapter, and k( T) was determined previously. X(T) is shown in Figure 6-9 for T = 1 mm. As T increases so that the curves move into the situation where multiple roots emerge, the system does not jump to them because it is already in a stable steady state. Only when Tq is so high that the heat removal line becomes tangent to the heat generation curve does the lower intersection disappear. The system then has no alternative but to jump to the upper intersection. A similar argument holds in the decrease in Tq from the upper steady state. 

For vapour pressure systems, the emergency relief system should be designed so that the action of the pressure relief system removes vapour (and therefore latent heat) at a rate fast enough to hold the temperature, and therefore the pressure, constant. This is referred to as a "tempered" reaction system (see Figure 3.3). In most cases, the rate of reaction does not then increase beyond this point. However, it is worth noting that, in some cases, the reaction rate. may continue to rise at constant temperature and pressure if ... 

Establish process control systems capable of maintaining conditions within safe limits (may include emergency cooling or heating systems). 

In addition to the normal temperature control provided by refrigeration and heating systems, separate temperature alarms should be considered. Both low and high temperature limit switches can be connected into the facility alarm system providing a more reliable means of monitoring area temperature. Finally, emergency generators should be considered where electrical power is critical for temperature control and the primary source is not reliable. 

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