Detection systems heat detectors

Confinement of Smoke and Fire FIRE-DETECTION AND -ALARM SYSTEMS Heat Detectors Smoke Detectors Flame Detectors Gas Detectors... 

AMD 1 Components of automatic fire detection systems. Part 5 Heat sensitive detectors point detectors containing a static element (AMD 5762) dated 31 August 1988. Superseded BS 3116 Part 1 1970... 

When dealing with an entire fire detection system that utilizes more than one type of detector, a Detonator Module greatly expands the flexibility and capability of the system. An individual Detonator Module can accept multiple inputs from UV and IR controllers, other Detonator Modules, manual alarm stations, heat sensors, smoke detectors or any contact closure device. In the event of a fire, any of these devices will cause the internal fire circuitry of the module to activate the detonator circuit, sound alarms, and identify the zone that detected the fire. When properly used, a Detonator Module will add only one millisecond to the total system response time. See Figure 8 for an illustration of a fire detection system with a Detonator Module. 

Smoke detectors are employed where the type of fire anticipated and equipment protection needs a faster response time than heat detectors. A smoke detector will detect the generation of the invisible and visible products of combustion before temperature changes are sufficient to activate heat detectors. The ability of a smoke detector to sense a fire is dependent on the rise, spread, rate-of-bum, coagulation and air movement of the smoke itself. Where the safety of personnel is a concern, it is crucial to detect a fire incident at its early stages because of the toxic gases, lack of oxygen that may develop, and obscuration of escape routes. Smoke detection systems should be considered when these factors are present. 

Deluge systems should generally be activated by automatic means. Activation by manual means defeats the objective of installing a deluge system, and fire water monitors should be provided instead as they are more cost effective where manual means is relied upon. Most systems provided at petroleum facilities are typically activated by a heat detection. Usually a fusible plug pneumatic loop detection system or UV/IR detectors are placed around the equipment. This insures activation when operators are not present and only when a real fire situation is present. 

Smoke detectors are primarily used where smoldering fires can be expected and where electrical equipment is located indoors. Examples of their use are in offices and sleeping quarters, computer rooms, control rooms, electrical switchgear rooms, etc. Their response is typically faster than that of heat detection devices. Smoke detectors are more susceptible to false alarms and usually multiple detectors are required to be in alarm before an extinguishing system is activated. 

Fire detectors—dry-pilot head and pneumatic rate-of-rise heat detectors are the most frequent devices used. A dry pilot head detection systems uses 165°F (74°C) V2-in sprinkler head with air pressure maintained in the piping. When the sprinkler opens the air is released resulting in the sprinkler valve opening. Other types of detectors include ultraviolet, infrared flame detectors, or thermostatic cable heat detection. 

A schematic block diagram illustrating an entire DP-SCD detection system is shown in Fig. 2. An analytical system consists of a gas chromatogr h equipped with a split/splitless iigector with the option of a Pressurized Liquid Injection System (PLIS), wifli or without low diermal mass gas chromatogr q)hy apparatus, for sample introduction and sulfur speciation (if required) an electrically heated burner with an interface that controls the burner gas flows and temperature and a detector that contains a chemiluminescent reaction cell, ozone generator, optical filter, amplifier, and electronics. Lastly, a vacuum pump is used to keep file reaction cell under low pressure conditions to prevent loss of chemiluminescent species and to reduce collisional quenching. 

Smoke detectors are particularly useful in those situations where the fire is likely to generate a substantial amount of smoke before temperature changes are sufficient to actuate a heat detection system and before a fire eye will detect a flame. Smoke detectors use a photoelectric beam between a receiving element and light source. If smoke obscures the beam an alarm is sounded. There are... 

If a demand occurs, the probability of the SIS being unable to perform as required equals the probabihty of failure on demand (PFD). Results later in the paper are assigned the corresponding SIL. The examples given in this thesis all belong to the low demand mode category, i.e. shut down valves, heat detectors and the like. We do not expect these systems to be activated often. Moreover, only dangerous and not on-line detected failures will be included. 

The System 80+ Standard Design is designed to preclude water spray from the fire protection system onto safety-related equipment. The sprinkler systems protecting the safety-related equipment is of the automatic sprinkler type. Actuation of these sprinkler systems requires the opening of the fusible link sprinkler heads and detection by combustible-products and/or heat detectors. In addition, the operator has the capability of isolating flow from the control room by isolating the Sub-sphere Building headers or, locally by manual isolation valves. 

---