TECHNICAL REPORT OG MSA 20/20MI Flame Detector Evaluation, 2004

Transcription

1 TECHNICAL REPORT OG MSA 20/20MI Flame Detector Evaluation, 2004 Author(s): D. Hooper Summary: This evaluation examines the suitability of the MSA (Spectrex) FlameGard 20/20MI (IR 3 ) Flame Detector for use on Shell Facilities. The evaluation includes a direct check of the manufacturers specification together with tests designed to provide information about how the detector may perform in operational environments. This review concludes that the MSA (Spectrex) FlameGard 20/20MI (IR 3 ) Flame Detector is recommended for addition to the approved list of flame detectors maintained by Shell Global Solutions. Keywords: MSA, 20/20MI, Flame, Fire, Detector SHELL GLOBAL SOLUTIONS (UK) Group August 2004 Shell Research Ltd., Cheshire Innovation Park, P.O. Box 1, Chester CH1 3SH, England. Tel: +44 (0) Registered in England No , Registered Office: Shell Centre, London SE1 7NA Shell Global Solutions is a trading style used by a network of technology companies of the Royal Dutch/Shell Group Shell Global Solutions (UK) is a division of Shell Research Ltd.

2 CONTENTS Page 1. PURPOSE OF THIS EVALUATION EVALUATION OBJECTIVES MSA (SPECTREX) FLAMEGARD 20/20MI MANUFACTURE S SPECIFICATIONS MODEL TYPES MANUFACTURERS PERFORMANCE DATA Standard Fire Sensitivity Ranges Sensitivity to other types of fuels Cone of Vision False Alarm Immunity OPERATION Visual Indications Electrical Signals Operational States Optional Alarm Latching BUILT IN TEST (BIT) Manual BIT automatic BIT mode NOT enabled Automatic BIT mode enabled FLAMEGARD 20/20MI PERFORMANCE ON-AXIS FLAME SENSITIVITY x 0.3m pool fires m Propane fire OFF-AXIS FLAME SENSITIVITY Heptane pool fire, off-axis tests Propane fire, off-axis tests REFLECTED FLAME SENSITIVITY LONG TERM WEATHER EXPOSURE ALARM SUSCEPTIBILITY TO SUNLIGHT Un-Modulated Sunlight Randomly Modulated Sunlight Regularly Modulated Sunlight SENSITIVITY TO FLAME IN SUNLIGHT Un-Modulated Sunlight Randomly Modulated Sunlight Susceptibility and Response to Blackbody Radiation TEMPERATURE PERFORMANCE PERFORMANCE DURING OPTICAL DEGRADATION TESTS POWER SUPPLY COMPLIANCE SENSITIVITY TO HOT EXHAUST FUMES CONCLUSIONS AND RECOMMENDATIONS APPENDIX...19 ADMINISTRATION PAGE Page 3

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4 MSA Flame Detector Evaluation, Purpose of this Evaluation The purpose of the test programme is to establish compliance with minimum performance standards required for the selection, installation and operation of detection equipment on Shell installations. This is carried out to enable operating companies within Shell to select detection equipment from an approved list, maintained by Shell Global Solutions Fire & Gas Consultancy. The approved equipment list ensures that detection equipment meets the minimum requirements 2. Evaluation Objectives The series of tests that make up the programme has been developed in-house. Where appropriate other applicable standards may be referred to. The main objectives of the tests are to evaluate: Equipment construction and installation Equipment features Environmental performance (temp, humidity and water spray) On and off-axis flame sensitivity across the operational range Long-term stability in weather exposure Response to reflected flame signal Speed of response for a range of fire types (materials) and sizes Mechanical integrity, vibration and alignment performance as appropriate Alarm susceptibility to sunlight, modulated sunlight and other artificial sources Alarm susceptibility to blackbody radiation Response to hot exhaust fumes Performance against electrical power supply variations Page 5

5 3. MSA (Spectrex) FlameGard 20/20MI Figure 1. The MSA (Spectrex) FlameGard 20/20MI Flame Detector 3.1. Manufacture s Specifications 1. Detection Range: 40m (Max) for 0.1m2 pool fire 2. Ultra High Immunity to false alarms 3. Advanced Digital Signal Processing 4. Three separate IR channels: 3 5 microns 5. Field programmable sensitivity 6. Two response levels: Warning and Detection. 7. Solar Blind 8. Microprocessor based 9. Built in self test: Manual and automatic. 10. Electrical Interfaces: Dry contact relays RS 485 Communication Network 4-20mA Output 11. Certification: ATEX (Cenelec) FM Page 6

6 3.2. Model Types The 20/20MI is offered in two ranges, (1) Standard for up to 40m and (2) Short Range fast detection up to 10 m. Further options include a choice of cable connection, housing material and approval Body. These options are detailed below in Table 1. Model Definitions 20/20MI -X X -X -X Models Std Range 10-40m 1 Short Range m 3 Outlets Cable Outlet 1 Plug Outlet 2 Housing S.S. 316 Aluminium Plastic S A P Approval ATEX (Cenelec) FM Non-intrinsic safe Table 1. 20/20 MI Options C F N 3.3. Manufacturers Performance Data Detection sensitivity is defined as follows: Detection sensitivity is the distance for a specified size of fire and type of fuel (Standard Fire) within a given time from the ignition of the fire Standard Fire A 0.1m 2 gasoline pan fire with a maximum wind speed of 2m/s Sensitivity Ranges There are four user selectable sensitivity ranges, with two response levels for each range Warning (10mA) and Alarm (15mA). The Warning level detection is configured to correspond to a distance increase of 10% over the Alarm level response. Table 2 details the manufacturer s performance for the 20/20MI 1. Sensitivity Setting Range (m) Response Time (s) Table 2. The alarm response time vs. range for 20/20M I-1 (manufacturer s data) Page 7

7 Sensitivity to other types of fuels The manufacturers report the following response to various fuel flames, based on the Standard Fire configuration with a maximum response time of 10 seconds. The de-rating of the sensitivity distance for a number of fuels is shown in Table 3. Type of Fuel % of max distance at each sensitivity range Gasoline 100% N-Heptane 100% Alcohol 95% 75% Jet Fuels 75% Kerosene 75% Diesel Fuel 70% Methane (0.5m plume fire) 30% Propane (0.5m plume fire) 30% Table 3 Sensitivity to other types of fuels Cone of Vision The manufacturer specifies the cone of vision to be an included angle of 100 o, in both the vertical and horizontal. However, at the extreme of 50 o off-axis, the sensitivity distance must be de-rated by 40%; the 100% rating is only available over an included angle of 80 o False Alarm Immunity Table 4 lists the manufacturers immunity data. = Immune at Any Distance. Radiation Source Immunity Distance (m) Sunlight Indirect or reflected sunlight Incandescent frosted glass light, 100W Incandescent clear glass light, rough surface, 100W Std fluorescent light, white reflector 1x40W or 2x20W Electric arc, 12mm gap, 400V, 60 Hz Ambient light and weather extremes Bright coloured clothing, including red and safety orange Electronic flash (180 watt-seconds minimum output) Movie light 625W quartz DWY lamp (Sylvania SG-55 or equiv.) 2 Flashlight (MX991/U) Radiation heater 1500W Radiation heater 1000W with fan Quartz lamp (1000W) 3 Mercury vapour lamp Grinding metal Lit cigar 0.3 Lit cigarette 0.3 Match, wood, stick including flare-up 3 Welding See Table 5 Table 4. False Alarm Immunity The specific, and important, case of welding is presented in Table 5. Page 8

8 Sensitivity Setting Detection Range (m) Immunity Distance (m) > > > >10 Table 5. Welding Immunity Distance for 20/20MI Operation Visual Indications A tri-colour status LED is located in the upper part of the detector window. Table 6 details the status information represented by this indicator. Detector Status LED Colour LED Mode Fault, BIT Fault Yellow 4 Hz Flashing Normal Green 1 Hz Flashing Gas Detected Warning Red 2 Hz Flashing Gas Detected Alarm Red Steady Table 6. Status LED information Electrical Signals The detector provides the following electrical outputs: 1. Alarm Relay 2. Fault Relay ma current output 4. RS-485 communications Operational States During operation, the detector will be in one of the following states (BIT = Built In Test): Detector LED LED Alarm Fault 4 20mA Description State Colour Mode Relay Relay Output Normal Green 1Hz Off On 5 ma Normal operation Warning Red 2Hz Off On 10 ma Fire detected warning state Alarm( 1)(3) Red Steady On On 15 ma Fire detected alarm state BIT Fault (2) Yellow 4Hz Off Off 2 ma Warning at BIT sequence fault detected Red 2Hz Off Off 10 ma BIT Fault detector will continue to Alarm at respond to fires Red Steady On Off 15 ma BIT Fault Fault Yellow 4Hz Off Off 0 ma Low power supply or s/w fault Table 7. Detector operational states. Note: 1) The alarm state can be latched (optional user select). 2) The detector will remain in BIT fault until a successful BIT has been performed. 3) The alarm outputs will be activated throughout fire detection, plus 3 seconds. Page 9

9 Optional Alarm Latching If the detector is configured with Latched Alarms, then the Alarm Relay, LED and signal current are set. Reset is by either toggling the power supply or by a successful manual BIT operation Built In Test (BIT) The Built In Test performs checks on the following: Electronic Circuitry Sensors Window cleanliness In addition to a manual activation, the detector can also be configured to perform an automatic BIT (every 15 minutes.). If the result of the BIT is the same as the current status, then the detector s status is unchanged. If the result differs from the current status, the BIT Fault is either set or reset depending on the previous state (Note in BIT Fault, the fire detection capability is still active) Manual BIT automatic BIT mode NOT enabled A manual bit is initiated by the momentary connection of pins 2 & 3, and activates the following: 1. Fault relay is closed. 2. If Function Alarm BIT set to YES, then Alarm relay is activated for 3 seconds. 3. If Function Alarm BIT set to YES, then 4 20mA output set to 15mA. 4. LED will show RED for 3 seconds. Should the BIT fail, then: 1. Fault relay is released ma output set to 2mA BIT Fault. 3. LED flashes YELLOW at 4Hz Automatic BIT mode enabled The detector will perform a BIT every 15 minutes. A successful BIT does not activate any indicator, the LED flashes 1Hz (normal) and the fault relay contact is closed (normal). An unsuccessful BIT will result in the Fault relay contact opening, the current O/P set to 2mA (BIT fault) and the LED will flash 4Hz. A BIT will be performed every 1 minute until successful. A manual BIT can still be initiated, however on an unsuccessful BIT, the detector will perform a BIT every 1 minute until a successful BIT has been performed. The detector will then resume normal operation. Page 10

10 4. FlameGard 20/20MI Performance In this section, the results of a number of tests on the detector s performance are presented. The detector s response is often presented as a speed of response figure. This has been achieved by exposing the detector to a fully developed test flame by initially shielding the detectors view. The recorded time is therefore the time taken from the removal of the shield until the detector registers an alarm. Note that the manufacturer s manual states the specification times are from the ignition of the fire. This was checked with the manufacturer and found to be an error in the manual that will be corrected. All testing was performed outdoors with the wind speeds below the manufacturers upper limit of 2 ms -1. This requirement was difficult to achieve and therefore some tests were performed with the mean wind speed greater than 2 ms - 1. However, in these instances, repeat measurements were made to capture measurements within the specification On-axis Flame Sensitivity The detector was mounted on a moveable platform and positioned at the recorded distance from the standard fire. The range setting was set appropriate for the test distance prior to the test. The detector was then shielded, the fire ignited and allowed to establish before the detector shield was removed and the time recorder started. The delay time was noted at the time the detector alarmed. The detector delay was set to the default anti flare mode. The long-range (40m) tests included a very heavy rainfall period. It was observed that the detection ability became very erratic or non-existent during the rainfall. This suggests that a possible performance fall off in heavy rainfall conditions could occur at the extremes of range x 0.3m pool fires These tests used a 0.3m x 0.3m pool fire of n-heptane. The results are presented in Table 8. Detector range setting (m) Distance (m) Response time (s) Manufacturer s specification (s) Table 8. 20/20MI Pool fire detection response. The results show the detector response was within specification at all ranges tested m Propane fire These tests were conducted using a Leader, Pyros fire generator. The generator produces a controllable propane flame. In these tests, the Pyros flame was set to a nominally 0.5m high plume flame. The results of these tests are presented in Table 9. The maximum detection distance, for each detector range setting, has been reduced according to the manufacturer s recommendations as presented in Table 3, Section Page 11

11 above. Note that this test is not a specification check of the detectors likely response to a propane jet fire as the controlled propane burner used does not produce a jet flame. Detector range setting (m) Distance (m) Response time (s) Manufacturer s specification (s) Table 9. On-axis 0.5m propane flame response. The results show the detector s response was within specification at all ranges tested Off-axis Flame Sensitivity This is carried out to determine the field of view and sensitivity for pool and jet fires. The detector was mounted with the viewing angle set to 30 o for both horizontal and vertical planes and response recorded at varying distances. Similarly to the on-axis tests, the fire was allowed to establish before the detector was exposed to the fire and therefore the recorded times do not include the time taken for the fire to initiate Heptane pool fire, off-axis tests. Detector range setting (m) Distance (m) Angle (degrees) Response time (s) Manufacturer s specification (s) Table 10. Off-axis heptane response. The results show the detector s response was within specification at all ranges tested Propane fire, off-axis tests Detector range setting (m) Distance (m) Angle (degrees) Response time (s) Manufacturer s specification (s) Table 11. Off-axis propane response. The results show the detector s response was within specification at all ranges tested Reflected Flame Sensitivity The ability of modern detectors to see fires due to the reflected signal off the steel structures, pipes and vessels in practical locations is important to ensure safe coverage in congested Page 12

12 areas. Although, the reflectivity cannot accurately be accounted for in the design of a fire detection system, a test of the ability of the detector to respond to indirect signal remains valid. In this test, a propane flame, (the Pyros propane burner mentioned above) was positioned 5m behind the detector with the detector looking 180 degrees away from the flame. A polished steel plate was then positioned at various positions in front of the detector. The detector was initially screened until the flame was established and the reflector positioned. The time to respond to the flame was then recorded from the time that the screen was removed. The detector was found to correctly alarm to the reflected fire with the reflector up to 3m away. This is a satisfactory result for this test Long term Weather Exposure The detector was left powered outdoors, and its O/P signal logged for a period of weeks. The detector showed no spurious events and the baseline signal was acceptably free from noise and drift. The detector was then exposed to further test fires without cleaning the window or re-setting the detector. The detector responded to the flames and the test performance was therefore satisfactory Alarm Susceptibility to Sunlight In operation, flame detectors may be subjected to a number of strong sources of infrared radiation. The sun is one such source, that if glinting off the sea, or reflected off wet and vibrating deck plates, may appear to be a modulated source. It is important that such signals do not produce false alarm signals. The tests performed below are designed to test the detector s solar blind-ness to un-modulated, regularly modulated and randomly modulated sunlight Un-Modulated Sunlight The detector was positioned 3m from a reflective plate such that sunlight was reflected onto the optical window of the detector for 60 seconds. The detector response was monitored. No response was observed from the detector and the test was therefore satisfactory Randomly Modulated Sunlight The detector was positioned 3m from an irregular reflective rotating disc such that sunlight was reflected onto the optical window of the detector for 60 seconds. The detector response was monitored. No response was observed from the detector and the test was therefore satisfactory Regularly Modulated Sunlight The detector was positioned 3m from an irregular reflective rotating disc such that sunlight was reflected onto the optical window of the detector for 60 seconds. An optical chopper was then interposed in front of the detector, providing modulations between 1 and 15Hz. The detector output response was monitored. No response was observed from the detector and the test was therefore satisfactory. Page 13

13 4.6. Sensitivity to Flame in Sunlight Although the above tests indicate the detector has a high degree of solar-blindness, it is important that the detector remains able to detect the potentially weaker infrared signal from a flame during periods when sunlight is present. The tests reported below therefore evaluate the detector s flame sensitivity the presence of un-modulated and randomly modulated sunlight Un-Modulated Sunlight The detector was positioned 3m from a reflective plate and sunlight was reflected onto the optical window of the detector. The detector was shielded and the Pyros propane burner positioned at 5m from the detector. The detector was then exposed to the reflected sunlight and the flame as the shield was removed. The detector alarmed to the flame with no adverse affect due to the reflected sunlight Randomly Modulated Sunlight The detector was positioned 3m from a reflective rotating disc such that sunlight was reflected onto the optical window of the detector. The detector was shielded and the Pyros propane burner positioned at 5m from the detector. The detector was then exposed to the reflected, modulated sunlight and the flame at the same time. The detector alarmed to the flame with no adverse affect due to the modulated sunlight Susceptibility and Response to Blackbody Radiation An additional source of infrared radiation that detectors may be exposed to is from hot bodies. Although modern detectors are unlikely to respond to the un-modulated black-body radiation, it is possible that the radiation may be modulated as it is reflected off rotating or vibrating equipment. The test described below assess the detector s ability to distinguish modulated black-body radiation from a flame. In the test, a 6kW infrared heater (approx 400 deg C) was placed 3m from the detector. Two chopper wheels were used to produce random modulation effects close to the detector. During the test, the modulation frequency is adjusted by changing the speed of rotation of the chopper motors and the detector response recorded for a range of modulation frequencies. The detector did not produce a false alarm during this test. To test whether the detector was able to detect the infrared signal of a flame in the presence of the modulated black body, the Pyros propane flame was then positioned at 2m and 5m from the detector. The detector correctly responded to the flame at both distances Temperature Performance To test the temperature stability of the detector, it was mounted in a Unitemp climatic chamber. The calibration certificate is shown in the appendix of this report). Temperature cycling tests were performed at a maximum rate of 20 deg C per hour over the range 20 to +50 deg C and the detector output signal was recorded. The temperature cycle test consisted of two complete cycles as follows: Page 14

14 1) Humidity set at 50%, temperature set at 25 C and held for one hour. 2) Ramp to 50 C at 20 C/hour. 3) Maintain 50 C for 3 hours. 4) Ramp down to 20 C at a rate of 20 C/hour. 5) Stabilise at 20 C fro 1 hour. 6) Ramp to 25 C at a rate of 20 C/hour. 7) Stabilise at 25 C for 1 hour. The results are presented in Figure 2 where the detector O/P signal is plotted against the chamber temperature cycle. The baseline signal remained within acceptable limits throughout the temperature cycle. During the temperature cycling tests, the detector s response to a propane flame and the Fire Simulator (provided by the manufacturer) was tested at both extremes of temperature. The detector responded satisfactorily to both stimuli at the lowest and highest temperatures. 20/20MI Climatic Chamber Performance Detector O/P (ma) Chamber Temperature (DegC) MI Temp Elapsed Time (s) Figure 2. Detector O/P during temperature cycling Performance during optical degradation tests. In use, flame detectors may be subject to salt-water spray, deluge water, oil mist and other substances that may contaminate the optics and prevent adequate flame detection. In this series of tests, the detector was mounted 9m from the Pyros propane fire generator. The detector range setting was set to 30m in accordance with the manufacturers specification for a propane flame at this distance. The detector was initially shielded and the fire started. Once the flame was established, the shield was pulled from in front of the detector. The time to alarm was recorded. The detector was then sprayed with a single Page 15

15 application of a test solution and the time to alarm test repeated. The detector was sprayed for the second time and the fire response test repeated. Without cleaning the detector, the detector was sprayed twice (totalling four spray applications) and the fire response test repeated. The detector was then cleaned, and the whole test sequence repeated with the remaining test solutions. The test solutions are listed, and the test results summarised, in Tables 12, 13, 14 and 15. Water tests Status Time to alarm Clean 4 1 spray 3 2 sprays 3 4 sprays 4 Table 12. Water spray tests. 50% Glycol in water tests. Status Time to alarm Clean 4 1 spray 4 2 sprays 4 4 sprays 4 Table 13. Glycol solution spray tests. Salt water solution Status Time to alarm Clean 4 1 spray 3 2 sprays 3 4 sprays 3 Table 14. Salt-water spray tests. Oil mist spray Status Time to alarm Clean 4 1 spray 3 2 sprays 3 4 sprays 3 Table 15. Oil mist spay tests. The results show that the time to respond to the fire does not increase significantly with moderate contamination of the optics to the test solutions. The detector therefore performed satisfactorily to these tests Power Supply Compliance Variation to the power supplied to a detector during operation may occur. It is important to ensure that the detectors remain within acceptable operating limits throughout the specified supply voltage range (18 to 32 VDC) During this test the detector supply voltage was varied across the range as the detector was exposed to both Fire Simulator and a propane flame. Page 16

16 The detector was found to respond to both real and artificial stimuli at either end of the quoted voltage range 18 to 32VDC Sensitivity to Hot Exhaust Fumes False alarms have been known to occur due to early models of flame detectors reacting to the hot exhaust gases. One of the major advantages of modern IR detectors is their ability to discriminate between real fires and other potential sources of infrared radiation. In this test, the detector was aligned to view the hot exhaust from the Pyros propane flame (the flame itself was not in the field of view). The detector did not respond to the hot exhaust gases and therefore responded satisfactorily to this test. Page 17

17 5. Conclusions and Recommendations 1. An evaluation of the MSA (Spectrex) FlameGard 20/20MI (IR 3 ) Flame Detector has been undertaken. This review forms part of a larger awareness study to guide Instrument Engineers and Procurement Specialists. 2. This evaluation of the MSA (Spectrex) FlameGard 20/20MI (IR 3 ) Flame Detector indicates the device is suitable for use on Shell facilities assuming operation within the manufacturers specified ranges and compliance with the relevant Shell DEPs. Page 18

18 6. Appendix Page 19

19 Administration Page Report Type: Report Number: Technical Report OG Title: MSA 20/20MI Flame Detector Evaluation, 2004 Issue Date: June 2004 Authors: D. Hooper Issuing Group: OGUK OGES Participants: P. Houghton OGUK OGES, Rizwan Malik OGUK OGES Keywords: MSA, 20/20MI, Mine Safety Appliances, Flame, Fire, Detector Sponsor/customer: MSA Great Britain Project/budget: DMS Activity Code: Requests for extra copies to be addressed through: Group (OGES) Administration Unit, Shell Global Solutions (UK), Cheshire Innovation Park. Electronic File: Owner/custodian, responsible for approving contents and distribution: Contact: David Hooper, OGUK OGES Tel: +(44) (0) Fax: +(44) (0) Original Distribution: (Please add recipient info as completely as possible, i.e. company name, location, recipient name and reference indicator for internal. Full postal address for external.) Shell Global Solutions (UK), Cheshire Innovation Park OGOI (Reports Archive) -1 copy Page 20

20 Report No:.OG Commercial-in-Confidence MSA 20/20MI Flame Detector Evaluation, 2004

21 This document is designated. Confidentiality Shell and the Customer shall keep confidential any commercial information identified by each other before disclosure as proprietary information, and shall not disclose such information to any third party. However, Shell may disclose such information as is necessary to a sub-contractor under paragraph 7 of the Terms and Conditions provided that prior to such disclosure the contractor has signed a confidentiality undertaking on the same terms as those in the Contract covering this work. If the Customer intends to disclose to Shell any technical information which is proprietary to the Customer or to any third party, it must first tell Shell the nature of that information and any restrictions on its use, and Shell shall have the right to decide whether or not to accept disclosure of that information. The Customer acknowledges and accepts that: (i) (ii) Shell shall not be obliged to provide any interpretation of the results; and Shell shall not be obliged to disclose to the Customer any information relating to the methods used by Shell in rendering the Services. Intellectual Property Shell retains all intellectual property in the test procedures and methodology developed by Shell which are not in the public domain, including any procedure and methodology developed by Shell in the course of providing the Services. Any data generated by Shell during the provision of the Services, other than data in respect of the methodology used or developed by Shell to obtain such data, shall be owned by the Customer, and the Customer shall be free to use and disclose such data as it deems fit, save that: (i) (ii) the Customer shall not mention Shell s names nor trademarks nor identify where the tests were done in any publication without prior written permission. Such permission will not be unreasonably withheld; any results do not imply implicitly or explicitly any warranty or endorsement of any procedure, product or service. Shell shall not disclose such data to any third party without the prior written consent of the Customer. This obligation of non-disclosure shall cease on the date the data comes into the public domain other than by breach of the Contract covering this work, or on the second anniversary of the date of the Contract covering this work, whichever is earlier. In the above, Shell means Shell Research Limited.