Smoke detection in challenging environments

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Smoke Detection Solutions for Challenging Environments

Trade-offs for Optimum Protection

Challenging Environments

Available Technologies

Open-area Smoke Imaging Detection and Applications ─ Technology overview

─ Field-proven applications

Industrial Very Early Warning Smoke Detection ─ Detection approaches

─ Deploying ASD in industrial environments

─ Field-proven applications

─ ASD criteria matrix

Agenda

Optimum Protection Requires a Balance

Fire Triangle

Detection Triangle

Challenging environments complicate achieving optimum protection

Provides the highest level of detection to ensure protection of… ─ Life

─ Property

─ Business continuity

─ Environment

Without false alarms that ─ Create disruptive false or nuisance alarms

─ De-sensitize personnel and occupants to alarms

─ Ultimately leading to disregarding alarms or disabling safety systems

─ Place an extra burden on local first responders

At an affordable cost ─ Initial installation cost

─ Long term operating, servicing, and testing costs

The Detection Triangle

A ‘Challenging Environment’ is a space where:

Detection is difficult due to:

─ Environmental conditions that cause false and nuisance alarms

─ Environmental conditions that shorten detector life

─ High and variable airflows

─ High ceilings

Detector sensitivity and longevity are compromised in

‘harsh’ environments due to:

─ Dirt and dust

─ Temperature extremes

─ High EMI

─ Moisture, fog, steam, water condensation

─ Birds and insects

─ Building movement

─ Sunlight

─ Detector location

─ Toxic and corrosive gases

A ‘Challenging Environment’ is a space where:

Maintenance is difficult

─ Extreme environmental conditions

─ Inaccessible areas

● High ceilings

● Roof or floor spaces

● Within elevator shafts

● Equipment racks

─ Restricted access

● High security areas

● Production areas

● 24/7/365 operation

Unobtrusive detection is required

─ To prevent vandalism or tampering

─ Not disruptive to architectural designs

─ Preservation of historic buildings and artifacts

Evacuation may be challenging

─ High concentration of large number of people

─ Exit paths are restricted

─ Occupants require assistance

Detection Technologies Overview in Challenging Environments – Large Open Spaces

Relative ranking: 5 = best / most desirable

Driver ASD OSID Beam VSD Laser Spot Flame L. Heat

Sensitivity to smoke 5 3 2 2 4 2 1 1

Prevent damage to structure 5 3 3 3 3 2 1 1

Prevent damage to contents (equip,

product, etc.) 5 3 3 3 3 2 1 1

Foreign particle rejection (dust, fog,

water, etc) 5 4 2 3 2 2 4 5

Foreign object rejection 5 5 2 4 5 5 5 5

Resistance to building movement 5 4 2 4 5 5 5 5

Operation in all lighting conditions 5 4 2 2 5 5 3 5

Equipment Cost 3 5 5 1 2 3 1 3

Installation costs 3 5 4 4 2 2 4 3

Maintenance costs 4 4 2 4 2 2 4 5

Total 45 40 27 30 33 30 29 34

New Advancements in Open-area Detection

Open-area Smoke Imaging Detection

Technical obstacles overcome

Applications

Industrial Very Early Warning Smoke Detection

Detection technology overview

New advancements in VEWSD for industrial

environments

Field-proven applications

ASD requirements matrix

False alarms due to…

Insects

Banners

Fork lift trucks

Challenges with Beam Detectors

Ladders

Watermist Spray

Building movement

Building vibration

Sunlight

Reflected sunlight

The improvements over traditional beam detectors stem from four core design ideas:

Dual-wavelength light frequencies

Digital imaging vs. photodiodes

A unique method for aligning

Smarter algorithms

What Makes Dual-wavelength Different

Large particle obscuration rejection

Use of UV & IR in specific wavelengths assist in evaluating whether

obscuration is caused by small particles in the physical size resembling

smoke or from larger particle (i.e. dust, steam, insects, fork-lift, ladders,

Tolerance to building shift and vibration

The multiple pixels of a CMOS imaging chip as opposed to a photodiode

along with the uniquely coded light beam from an emitter provides the

ability to track the position and tolerate movement

Foreign light intrusion

The Imager is fitted with a dyed glass filter, designed to be almost opaque

except to all but two wavelengths of interest

Overcoming Conventional Challenges

Emitter

Obstruction

Smoke Imager

UV beam

IR beam

Active emitter LEDs transmit wide beam IR and UV to the Imager

– IR and UV have differing wavelengths

– Respond differently to smoke

Relative strengths of the UV & IR are compared

– Detect smoke

– Discriminate against particulates that cause nuisance alarms on traditional beams

Software locates illuminated pixels on the CMOS imager

– Each emitter is uniquely coded

Imager software tracks building movement

– No controlled motor drives

Dual-wavelength vs. Single IR Beam

Imager versus photodiode

One imager equals 100,000’s

of photodiodes

An Imager locates and tracks

the position of an emitter

anywhere in its field of view at

pixel level

Can operate reliably in all

lighting conditions; bright day /

sunlight to total darkness

Emitters

Actual view from a 45 degree imager with 4

emitters in a 13,500 sq ft area

Powerful Benefits

Simple and easy installation using a unique Laser Alignment Tool

─ Requires only rough alignment due to the wide angle of view of the

imager(s)

─ Up to 70% time saving compared to traditional beams

Beam length up to 492 ft

─ Outperforming traditional beams by up to 50%

Installation & Commissioning

Real Field Challenges

Overcome by Open-area

Smoke Imaging Detection

Long Distances

Reliably detecting at 497 ft

Allows for 20% setting at 430 ft

Aligned through metal support

structure of the roof

Industrial Site

6”/15 cm

End-user was considering

linear heat cable for

‘controlled’ burn down…

Metro Station and Tunnel

5,85 “/15 cm

75ft/23 m

69ft/21m

187 ft/57 m

High ceiling

Low ceiling

46 ft/14 m

See effect of whirling dust

when metro comes into

the station

Cathedral York Minster

5,85 “/15 cm

Reliably detecting on 72

feet high on distance of

400 ft

Fire tests

5,85 “/15 cm

Effect of six Viking-style torches.

Nuisance or alarm, now you

know and choose

Cathedral York Minster

Semi-open Warehouse

Example of the effect of condensation

on the emitter

No differentiation between IR and UV

and hence no alarm nor faults

Chicken Farm

5,85 “/15 cm

Spikes with up to 20% when

chickens run around.

Estimated time between

cleaning of lenses 2-3 month

Series1

Series2 IR Att

Carton Printing Facility

Water mist is sprayed every few

minutes to maintain a humid

environment

This happens 24/7, the water mist is

causing false alarms on installed

UV Att

Recycling Plant

5,85 “/15 cm

Estimated time between

cleaning of lenses 1 month

Recycling plant 2

5,85 “/15 cm

Providing the best solutions means

also knowing what does NOT work

and exactly WHY

23/12 10:48 23/12 12:00 23/12 13:12 23/12 14:24 23/12 15:36 23/12 16:48 23/12 18:00 23/12 19:12 23/12 20:24 23/12 21:36 23/12 22:48 24/12 0:00 24/12 1:12 24/12 2:24 24/12 3:36 24/12 4:48

Date/Time

IR Atten

UV Atten

Direct Sunshine

5,85 “/15 cm

Disregarding the ‘avoid East – West

direction’ recommendations, Dual

Wavelength only generates a

saturation fault when exposed directly

to the sun.

New Advances in Open-area Detection

Open-area Smoke Imaging Detection

Technical obstacles overcome

Applications

Industrial Very Early Warning Smoke Detection

Detection approaches

Deploying ASD in industrial environments

Field proven installations

ASD requirements matrix

Technology Approaches to Very Early Warning Smoke Detection

Detection Approaches

− Absolute

− Adaptive

Impact on Detector Performance

− Fixed thresholds

− Drift compensation / dynamic thresholds

− Dust rejection

System Integrity

Continued…

Xtralis detectors use clever patented methods to ensure all optical

surfaces are free from contamination throughout their life

Clean air barrier protects optical surfaces

Eliminates detector drift

Consistent & predictable alarm thresholds

Field adjustable, fixed detection thresholds

Absolute Detection

1. Establish background levels

2. Select alarm thresholds

Dirty Environments Establishing Fixed Alarm Thresholds

Fire 1

Action

Background

Fire 2

Smoke test

Mathematic algorithms used to compensate for detector drift caused by

non smoke particles entering the smoke chamber or electrical

interference induced into the detection system

Short term events

Long term drift

Drift compensated alarm thresholds

Adaptive Detection - Drift Compensation

Drift Compensation Risks

Alert Level

95 min

145 min

Drift compensation can result in

significant detection delay

Detector output

Approaches used to compensation for dirty backgrounds

─ System pipe network design

─ Background compensation

─ Filtration

─ Maintenance

─ Particle size rejection

Particle size

Smoke Dust

Smoke detector patents for particle size discrimination

US 7564365: Marman & Eggers - GE Security

US 7483139: Powell - Kidde IP Holdings

Dust – an Environmental Challenge

The Conundrum:

Rejecting smoke, dust, or both?

Particle size

Smoke Dust

Typically

Smoke 0.1 – 6 m

Dust 1 – 100+ m

Mulholland, G.W. , SFPE Handbook of Fire Protection

Engineering 2nd Ed, Ch 15, Section 2.

Lide, D.R. (1994) , Characteristics of Particles and

Particle Dispersoids, Handbook of Chemistry and

Physics, 75th Ed.

Dust Rejection – an Environmental Challenge

Dust rejection may result in reduction in

detector sensitivity

1 ”A comparison of Aspirated Smoke Detectors. Honeywell

FAAST Detectors and Xtralis VESDA VLF LaserFocus”

Conducted by Packer Engineering, Inc and The Fire

Testing Evaluation Center at The University of Maryland,

College Park, Nov 2010

Adaptive vs Absolute Detection

Adaptive Detection

Absolute Detection

Dust Rejection – the Consequences

Sample Holes

Return-air Grill

1 NA: No Alarm within 300sec

Test ID

Response Time (sec)

Absolute

Detection

Adaptive

Detection

1 188 sec – Alert NA1

2 220 sec – Alert NA

Test Fire

Time to Alarm (sec)

Absolute Detection Adaptive Detection

Alert Action Fire Alert Action 1 Action 2

5 Timber -smoldering 590 787 NA1 799 NA NA

6 PU foam -smoldering 628 876 NA NA NA NA

7 PU foam -flaming 140 167 198 190 NA NA

8 Heptane - flaming 78 143 266 175 NA NA

9 Paper – smoldering 660 NA NA NA NA NA Tests witnessed by Centre for Environmental Safety

and Risk Engineering (CESARE), Victoria University,

Melbourne, AU 37

Adaptive vs. Absolute Detection

Electrical integrity

Detection chamber

Pipe network flow monitoring

- Ensure that it cannot be by-

passed

Filter life monitoring (currently on

the market)

- No monitoring

- Time based

- Particle counting

- Through filter flow monitoring

The FACP says these detectors are

fully functional

System Integrity – Critical Functions Must be Monitored

System Integrity – time based filter monitoring

Unsupervised Detection Failure 39

Sensitivity vs. Filter Loading Cycle

Intelligent Filtration

Larger x% of flow passes through

HEPA filter

Smaller y% of flow passes

unfiltered

Flows recombined

to enter detector at lower

obscuration than original

Pipe Flow Splits into x% and y%

Flow Sensors

Air coming directly from sampling pipe

(total airflow)

Reduce contaminates

entering detection chamber

Innovative flow partitioning

and HEPA filtration

Continuous monitoring of

filter and airflow

Optimum detector sensitivity

over detector life.

Very Early Warning Smoke Detection in Industrial Environments

Perceptions of ASD

ASD Comfort Zone (Roots in Data Center and Telecommunications)

Uncomfortable Zone (Industrial)

Dirty Clean

Designed for the cleaner environments

Industrial applications beyond ASD capabilities

Market skepticism still exist

Historically ASD system designs in all industrial

environments required system application engineering 42

Improved general protection

− Hardened product enclosure – IP/NEMA rated

− Eliminate need for secondary enclosures

Longer pipe run to accommodate larger facilities

Greater visibility of status LED

Improved filtration

− External filtration can stress system maintenance

− Eliminate need for external filters

Field serviceable modules

− Less down time

− Lower spare part inventory

Lower long term operating costs

Establish standard to quantify contamination resistance

Industrial Applications Require More from ASD

IP54 Enclosure

Intelligent filtration

1,200 ft. pipe runs

High intensity status LED

Field serviceable – modular

construction

Fit for purpose Industrial ASD

Enhanced filtration & IP-rated enclosure

can reduce Total Cost of Ownership by 40 to 60%

In-line Filters

Detectors inside protective enclosures No protective enclosures required

No In-line Filters

New Approach to ASD in Industrial Environments

Filters

Aspirator

Detection chamber

Fewer spare parts – less down time

Electronics

Modularity Delivers Lower Total Cost of Ownership

Power Plant – USA

Steel Mill – USA

Industrial Installations

Illovo Sugar Mill – South Africa

Cook Colliery – Australia

Boiler Feed Pump

ASD Protected from extreme

heat via pipe network

Battery rooms

ASD + hydrogen gas detection

Power Plant

300 foot tunnel under electric reheat

furnace

Furnace utilizes nitrogen protective

atmosphere – risk of oxygen

depletion (asphyxiation)

Cable trays – risk of fire

Solution: Industrial ASD + Oxygen

Steel Mill – Tunnel Protection

ASD Detector in

Protective Enclosure

Industrial ASD

Detector

Illovo Sugar Mill – Pipe Network Design & Installation

Cook Colliery – Underground Mine

Cook Colliery – Pipe Network Design

Cook Colliery Installation

Contamination

Computer / Control / Clean

Rooms / Data / Telco

Switch Rooms /

Warehousing

Conveyor / Mining

/ Other

Switch / Substation / Warehousing / Factory / Recycling / Processing /

Manufacturing / Power Gen / Conveyor / Mining , High Dust, Etc.

Additional considerations

may be required

In-line filters (Optional)

Contamination

Bagasse / Coal/

Underground

- Various Manufacturing and

Warehousing Applications -

Fertilizer / Paper / Steel /

Tunnels / Etc.

Semi Conductor / Communication /

Control / Data

May require

applications

engineering

In-line filter

Evolution of ASD Applications

ASD requirement matrix

- Consistent Alarm Thresholds over detector life

- Determinate alarm thresholds (% obs/ft or %obs/m)

- Ability to compensate for background levels

- Flow system monitoring that cannot be by-passed

- Active filter life monitoring

- Quantified contamination resistance (for industrial)

Proposed contamination test

Dust type: per ASHRAE 52.2

Dust loading density: 16mg per cubic meter

Test cycle: (dust - clean air - smoke)

Dust duration: 3.5 hours

Clean air: 30 minutes

Smoke test: smouldering cotton - two exposures

Number of test cycles: 10

Allowable sensitivity drift: <15%

Proposed ASD Criteria Selection Matrix