Fire Detection

Go to Specific Titles:- Flame Detector Selection | Fire / Flame Detection | Flame Detector Maintenance | Fire Systems Integrity Assurance | Reducing False Alarms from Automatic Fire Detection Systems | Oil Mist Detectors | Point Detector Cleanliness | Smoke Detectors | Visual, CCTV Fire and Smoke Detection Techniques


Flame Detector Selection

Flame Detector Selection - Ian Davidson - There are two distinct flame detection families:

  • Radiation flame detectors consisting Ultraviolet, Single Frequency Infrared, Combination UV/IR, and Multiple Frequency Infrared.
  • Visual Flame Detectors

Radiation-type flame detectors collect radiation from the area under surveillance, sum the total radiation within the field of view, analyzing the total intensity of the radiation and any flicker frequency that exists.

The second family, Visual Flame Detectors, are based on a CCTV camera with processing built into the detector the fire decision is made by the detector. This type of detector analyzes each area of interest within the field of view to determine if each area meets the criteria for fire. The radiation from each potential fire source is analyzed individually. Many thanks to Micropack Engineering.

Selecting an Optical Flame Detector - There are several types of optical detector available from single wavelengths of UV, and IR to combinations UV/IR and multi wavelength IR's (dual and triple). Each type of detector having differing flame detection performance (not just by type but also from manufacturer to manufacturer). This article looks at the more fundamental differences and design considerations for the selection of Optical Flame detectors - from the ISA.


Fire / Flame Detection

Detection Down to the Right Temperature - The detector is of vital importance in a preventative protection system. Firefly has a unique position in the market for detecting ignition sources in different applications. The Firefly technology detects dangerous particles, flames and are designed to minimise the risk of false alarms. All fires and dust explosions have an ignition sequence. An effective means of protection is to neutralize the small amounts of energy (ignition sources) before they manage to ignite the fine particles - Thanks to FireFly and PROdetec.

Test Lamp for Multispectrum Flame Detectors - This is a useful tool. Hazardous Area Certified Test Lamp for a range of Multispectrum Optical Flame Detectors covering both IR3 and UV/IR detection range. The LT15 is a handheld flashing test lamp for functional test of optical flame detectors. The emission spectrum of the lamp covers both UV and IR detection range. The emission is modulated to simulate the typical flickering of flames. This allows testing of most UV, IR and UV/IR flame detectors as well as Simtronics range of MultiSpectrum Optical Flame Detectors (IR3 & UV/2IR) It is ATEX approved Ex d IICT6-T5 and suitable for operation in hazardous areas, (area 1 and 2) in accordance with the EN 60079-0 and EN 60079-1 (2004) standards. From ProDetec.

Handbook for Fire Detection Systems and Emergency Warning and Intercommunication Systems - The purpose of this handbook is to provide information on the various configurations available for Fire Detection Systems. Appendixes on AS1668 controls and emergency warning systems have been included as they form part of the modern day requirements for fire control - from Ampac.

Fire and Gas Detection - From the UK HSE - There are two principal types of detector which are commonly in use in off-shore installations: heat, flame & smoke, and flammable gas instruments. The most significant for risk reduction are gas detection systems, since they give the earliest warning of hazardous situations. Infra Red (IR), line-of-sight or point type detectors which identify an accumulation of gas and acoustic leak detectors, are also used. The OSD strategy is to promote the use of a combination of sensors, thereby giving early leak detection with the acoustic detectors and identifying a gas cloud accumulation with the IR type sensors.

Applying Neural Network Technology to the Next Generation Flame Detector - from General Monitors - Accurate and reliable industrial flame monitoring has always represented a technical challenge. The main flame monitoring concern lies in the requirement to differentiate spectral radiation emitted by flames from that of background radiation, which is always present in the industrial environment. Insufficient differentiation of flames from background sources typically causes the highly undesirable condition of false alarm. When a false alarm condition occurs, it activates automated fire suppression equipment, causes operational interrupts, consumes extinguishing materials, and requires resolution of the alarm condition, which can include a complete system shutdown and restart. The development of Neural Network Technology for multi-spectral optical flame detectors helps to resolve the problems described.

How to Select a Flame Detector - Process and plant engineers in the oil and gas industry and a wide range of other hazardous process and manufacturing industries require continuous flame monitoring equipment to prevent catastrophic fires. In order to select such detection equipment, users should understand the principles of flame detection and review the types of detectors available today. Armed with this knowledge they will be better able to match the appropriate flame detector to process and site performance requirements and to the type of hazard whose consequences the instrument is designed to mitigate - from General Monitors.

Detecting Hydrogen Fires - Hydrogen fires emit large amounts of UV and IR radiation and almost no visible light radiation. Detecting a hydrogen fire is difficult due to mostly an invisible flame. The Kennedy Space Center uses flame detectors designed to detect hydrogen fires during launch operations. The flame detectors are used on the cross-country fuel lines, launch pad service structures, and Mobile Launcher Platforms (MLP) - from General Monitors.

The Fire Industry Association (FIA) is a not-for-profit trade association with the aim of promoting the professional status of the UK fire safety industry. The FIA's main objective is to promote the professional standards of the fire industry. They provide technical knowledge and advice to anyone who needs it regarding fire safety in the UK. This site is an excellent Fire Detection and Protection resource. It provides;

  • Technical Updates - General technical information of interest. This includes consultation requests from UK Government on new or proposed legislation, public comment drafts of Standards, and comment drafts of FIA technical documents as well as the notification of publication of new standards and legislation.
  • Fact Files - Fact Files are a collation of technical, legislative or procedural facts on a single subject or closely associated group.
  • Guidance Notes - These are recommendations and interpretations by the FIA (written by Council, Committee, and Secretariat etc) to give help and guidance to members and non-members on technical subjects, legislative matters, FIA processes/procedures etc.
  • Codes of Practice - These are ‘how to’ documents that are drafted and formatted in a similar fashion to a national standard by the FIA (written by Council, Committee, and Secretariat etc) to give help and guidance to members and non-members, primarily on technical subjects.

Frequently Asked Questions about Flame Detection - A useful series of Questions and Answers related to types of Flame Detectors, location and installation, design and much more - from Desu Systems.


Flame Detector Maintenance

Design Guidelines for Point Type Multisensor Fire Detectors and Associated Control and Indicating Equipment with Respect to Field Testing - This document provides guidance on the design of point type multisensor fire detectors, associated control and indicating equipment (CIE), and field test equipment functionality to facilitate field testing of such multisensor devices. The aim is that simple and efficient field testing shall be possible, according to previously-issued FIA guidelines and BS5839 pt1 recommendations - from the FIA.


Fire Systems Integrity Assurance

Fire Systems Integrity Assurance - Experience has shown that fire detection and protection systems are not always designed or specified in sufficient detail to ensure that they meet the performance criteria necessary to reliably achieve their intended role; this can result in fire systems not providing the performance required when called upon to do so. The OGP has produced a Fire System Integrity Assurance report, which provides guidance on issues involved in the assurance of fire system integrity from development of appropriate performance criteria through to routine system testing and inspection, in order to assess ongoing performance against the original criteria. The objective of the report is to provide a high level model of the steps to be addressed in assuring fire system integrity and to give guidance on technical points to be considered at each stage, drawing on practical experience from oil and gas installations - from OGP.


Reducing False Alarms from Automatic Fire Detection Systems

Managing False Alarms - For users of Automatic Fire Detection and Alarm Systems - This guide has been produced to advise and give recommendations for all users of automatic fire detection and alarm systems ways in which to avoid unwanted alarms, be they malicious, accidental or arising from neglect of a system - From Chubb UK.

Chief Fire Officers Association  Protocol for the Reduction of False Alarms & Unwanted Fire Signals - The Aims Of This Protocol are to; Provide a uniform process for those parties involved in managing the reduction of false alarms and UwFS, reduce the number of false alarms generated by fire detection and AFAS, reduce the numbers of UwFS sent to FRSs and provide the most appropriate response - from the FIA.

Guidance for Responsible Persons on False Alarm Management of Fire Detection and Alarm Systems - This is a generic guideline, for the end user or ‘Responsible Person’, to manage and ultimately reduce false alarms from a building’s fire detection and alarm system - from the FIA.


Oil Mist Detectors

The following excellent technical articles are from the Quality Monitoring Instruments Ltd:

Oil Mist and Machinery Space Fires - Dr MH Holness - This paper details the role of oil mist as a principal agent in machinery space fires. The ways in which oil mist can be produced are described and the distinction between mist and spray. The contrast between the oil mist conditions inside crankcases and that in the general atmosphere in machinery spaces is discussed. Methods of measuring oil mist and spray are described and equipment suitable for monitoring conditions inside machinery and in machinery spaces is discussed. Recommendations are made to improve safety on board ship and in industrial plant.

Oil Mist Detection as an Aid to Monitoring an Engine's Condition - Brian J. Smith - Advances in technology have been such that health monitoring has now become increasingly important with regard to diesel engine maintenance and safety. Oil mist can give some of the first signs of impending problems for all the moving parts of the engine. It is acknowledged that temperature and pressure indication can also provide appropriate early warning of potential problems with certain components, particularly those components that can be fitted with temperature probes.

Oil Mist Detection in the Atmosphere of the Engine Room - Brian J. Smith - You may be aware MCA and IMO, together with other Societies, are very concerned about the number of fires that start in machine room spaces. Places most at risk are engine and purifier rooms. However, other areas have their own problems and these include bowthruster rooms, steering gear and hydraulic pumps. Figures produced suggest that up to 65% of machine room fires are the result of oil mist.

Oil Mist and Machinery Space Fires - Dr MH Holness - A review is presented of the role of oil mist as a principal agent in machinery space fires. The ways in which oil mist can be produced are described and the distinction between mist and spray. The contrast between the oil mist conditions inside crankcases and that in the general atmosphere in machinery spaces is discussed. Methods of measuring oil mist and spray are described and equipment suitable for monitoring conditions inside machinery and in machinery spaces is discussed. Recommendations are made to improve safety on board ship and in industrial plant.

IMO Code of Practice for Atmospheric Oil Mist Detectors (PDF format - 234K) - International Maritime Organisation


Point Detector Cleanliness

Guide to (Point) Detector Cleanliness - Some excellent tips of how to clean Fire Detectors - from the FIA.


Smoke Detectors

Smoke Detection in High Spaces using Aspirating Smoke Detectors - Reliable detection of smoke in high ceiling spaces has been considered a challenge for many years and most Design and Installation Codes (including BS5839-1) define limits on the ceiling height that may be protected by a particular technology. Most practitioners default to using detection technologies - such as Optical Beam Smoke Detectors (OBSD) or Aspirating Smoke Detectors (ASD) - which derive their smoke measurement over an area - not at a single location. Such "integrating" technologies are inherently more sensitive to smoke that is diluted or distributed as it rises to higher levels than point type detectors. BRE Global has recently completed a research project jointly funded by the BRE Trust and the FIA to review the recommendations provided for using OBSD and ASD in high ceiling spaces. The results of this research are published in a BRE Information Paper but are summarized in this Fact File along with news of how the results have influenced changes to the FIA Code of Practice for ASD Systems - From the Fire Industry Council.

Application Guidelines for Thermally Enhanced Carbon Monoxide (CO) Fire Detectors - This FIA Fact File provides guidelines for the use of fire detectors utilizing carbon monoxide (CO) sensors based on electrochemical cell technology enhanced by one or more thermal sensors. It covers detectors where the thermal sensor(s) may also provide a response to fire independently. This Fact File does not give guidelines for detectors which incorporate additional or other sensing technologies. This Fact File does not give guidelines for CO gas detectors for environmental monitoring or toxic gas detection.

Application Guidelines for Carbon Monoxide (CO) Fire Detectors - This FIA Fact File provides guidelines for the use of fire detectors utilizing carbon monoxide (CO) sensors based on electrochemical cell technology.

Code of Practice for Design, Installation, Commissioning & Maintenance of Aspirating Smoke Detector (ASD) Systems - The Code of practice provides recommendations for the planning, design, installation, commission and maintenance of aspirating smoke detection systems. It identifies categories of ASD systems and typical applications where such systems can be used. It also provides specific design rules on common applications and guidance on good practice - from the Fire Industry Association.

System Smoke Detectors - The purpose of this excellent guide is to provide information concerning the proper application of smoke detectors used in conjunction with fire alarm systems. The guide outlines basic principles that should be considered in the application of early warning fire and smoke detection devices. It presents operating characteristics of detectors and environmental factors, which may aid, delay, or prevent their operation - from System Sensor.


Visual, CCTV Fire and Smoke Detection Techniques

The Following technical papers are from Micropack Engineering:

Is there an Alternative Technology Better Equipped than UV or IR to Reliably Detect a Flame? - Image capture from a CCD pixel array is possible via the photoelectric effect, where light energy is produced by the flame’s incandescence. Photons are emitted from the flame then received by the pixels of the array, creating a picture of the flame. The photoelectric effect transforms the energy intensity from the photons into a proportional electrical charge - from Micropac.

Flare Radiation - Not So Friendly Fire - Ian Davidson - Most hydrocarbon and chemical process plants provide a relief flare or vent to assist in handling process upsets. A typical relief flare operating at, say 0.1kg/sec under normal conditions and 10kg/sec under relief conditions will provide flame energies in the order of 2 MW and 100MW respectively. Where a cold vent (rather than a flare) is provided, lightening strikes are surprisingly common and there are many reported instances of an unintentional ’hot’ vent. In addition to the local relief flare, the possibility of a system being activated by an adjacent unit’s or site’s flare cannot be ignored. This latter case can result in a ‘domino’ effect that has provoked a number of unscheduled relief (and vent-snuffing!) system tests over the years. Clearly the fires associated with a flare are several orders of magnitude greater than the target fire size and exhibit precisely the infrared radiation signature required by an IR3 detection.

Visual Flame Detection - Optical flame detection has evolved over the last 30 years with improved sensors, processing power, and high electronics reliability, which has greatly improved the acceptance and use of automatic optical fire detection in the harshest of environments and applications. Single wavelength ultraviolet (UV) detectors were originally used for the protection of large integrated oil and gas production platforms in the North Sea, followed by single wavelength infrared (IR) detectors, but problems with false alarms from numerous natural and artificial sources both on the platforms and from adjacent installations prompted the oil industry to search for a better technology. This paper covers the recurring problem of flare reflections on offshore platforms and how the evolving technology of visual flame detection has solved this problem.

Guidance on Video Smoke Detection Technology (VSD) - This FIA Guidance Document provides an overview of video smoke detection technology (VSD) based on the analysis of video signals from CCTV cameras and gives some basic guidelines as to its application in fire detection and alarm systems - from the FIA.

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