spark detection and extinguishing system. spark detection – markets initiative from finnish...

Spark Detection and Extinguishing System

Spark Detection – markets

Initiative from Finnish insurance companies Need for technically competitive and cost

efficient Spark Detection System ATEX (94/9/EY, 1992/92/EY) directives

Regarding potentially explosive atmospheres and machines and devices used in them.

State council statute obligates employers to evaluate possible risks regarding dust explosions and in case of risk move to corrective actions

Spark Detection – Dust explosion

Dust explosion is a fast burning reaction. Dust explosion moves forward from the

ignition point spherically lifting pressure and thus causing damage to constructions

Dust explosion is possible, when there is enough fine material mixed with air and a spark or high enough temperature

Material can be almost anything as long as it is fine enough.

Spark Detection – What it does

The purpose of the system is to extinguish the detected sparks before they cause a dust fire or a dust explosion.

Following systems can be protected with the system: Saw dust outlet systems Dust outlet systems Grinders and pellet burners

Spark detection and extinguishing system is not used for protecting rooms

Spark Detection – markets

Applications in mechanical wood processing industry and more accurately:

sawdust outlet pipes, conveyors etc

Potential customers: carpenters, sawmills,

planing mills, furniture factories, schools, paper mills…

Spark Detection – Principle

Extinguishing unit Spark detectors

Saw dust outlet pipe

Air flow

1. Spark detectors and extinguishing unit Basic system includes only two detectors and an extinguishing unit Extinguishing unit is a part of the Spark detection system




Air flow

Panel

2. Detectors, extinguishing unit and panel By adding a panel to the system, it is possible to

– get info of the possible alarms (siren and beacon)

– shut down machines in the production process

– test the system




Air flow

Panel

FX 3NET

3. Detectors, extinguishing unit, panel and FX 3NET Spark detection system panel can be connected to a control

computer via ModBus-fieldbus. This enables for example the monitoring of alarm log

Spark Detection – connection to fire alarm panel

The system is usually used as an individual system

The system can be connected to a fire alarm panel, if: the alarm needs to be transmitted to the fire brigade the alarm information needs to be tranferred to the fire alarm panel

locally

Spark Detection - System

The system consists of three different main blocks:

Detection Detectors Test lamp

Control Control Panel Alarm devices (sounder and beacon) Signal router

Extinguishing Extinguishing unit Pressure boost unit

Spark Detection – System Components

The System consists of three main blocks Spark detector

- Detects the sparks and controls the extinguishing unit

- Transmits the info about the extinguishing events to the panel

- Measure area UV - IR Fulfils the requirements of: EN50081, EN50082, EN50130-4, EN54-

1, IEC60068-1/2


Spark detection panel- Works as a human interface - Shuts down machines in alarm state- Measures device temperatures- Communicates with control computer via ModBus (option)

- System can be connected to Esmi FX Fire panel Integration


Extinguishing unit– Extinguishes sparks with a fine water screen. Extinguishing unit is

fault monitored by a flow switch and also by the panel.– Extinguishing unit is used in saw dust outlets under 450mm diameter– The self cleaning unit is designed so that the particles flying in the

pipe will not damage it

Extinguishing unit


Extinguishing unit– Extinguishes sparks with a fine water screen.

Extinguishing unit is fault monitored by a flow switch and also by the panel.

– Extinguishing unit is used in saw dust outlets over 450mm diameter

– The self cleaning unit is designed so that the particles flying in the pipe will not damage it

Extinguishing unit


Pressure booster (part of the extinguishing unit)

– Requirements for the water and electric suplies:

• Water pipe min. DN28 and flow 100l/min/nozzle

• Motor voltage 3*400V and current 5A

Pressure booster consists of a water pump and diaphragm pressure tank

Spark Detection – Installation requirements

Pressure booster Electrical connections has to be done by an electrician Pipework has to be done by a plumber

Planning or installing of Spark detection systems in Finland does not require same kind of qualifications as in case of sprinkler systems.

Spark detection systems are not EN standardised. Planning and installations should done according to European Insurance Committee: CEA 4044 - Specifications for spark detection, spark extinguishing and spark diversion systems – Planning and Installation


120 Spark detectors and AN6400 Panel


Extinguishing unit


Pressure booster


Alarm devices, siren and beacon


Temperature monitoring


Expansion options

Spark Detection – System planning

System response time from detection to extinguishing is <100ms Extinguisher units are installed in direction of air flow after the detectors

Detector

Extinguishing unit

F


The distance between extinguishing unit and detector is calculated with the following formula

d= F x 2D, where

d = min. installation distance

F = air flow speed (typ. 20-30m/s)

D = System delay (<100ms)

Calculated with 25 m/s air flow d = 5m

Manufacturers ”thumb rule” d = 7m

F

d


The bigger the diameter of the pipe is, the more water has to be injected into it. The needed water amount can be calculated with the following formula:

Q = F x A x B, where

Q = water amount needed l/s

F = air flow speed (typ. 20-30m/s)

A = pipe cross area π x r²

B = constant 0,2l/m³ (0.2 litres water / 1m³ air)

Spark Detection – extinguishing unit / nozzle

Nozzle in the pipe on the left In this picture there is a nozzle

designed for 400 mm pipe in a 700 mm pipe

Spark Detection – Installation pictures

Detectors and a test lamp

Detectors are installed facing each other on the sides of the saw dust outlet pipe. This way maximum visibility of the detectors is achieved.

Detectors must not be installed in the bottom of the pipe. Danger of coverage.

Detectors must not be installed just after a corner. Danger of breakage.

Signal router

Spark Detection – Installation pictures

Detectors and Signal router

Detectors

Panel

Pressure Booster

Signal router

Extinguishing unit

Sounder and Beacon

Smallest detector in the market Very fast response time (1ms)

Fastest System response time on the market Detector and extinguisher can be installed near to each other thanks to

fast System response time - > less extinguishers outdoors -> less separate extinguisher

warmers Minimized extinguishing water -> less problems with filters

User friendly, easy user interface Cost effective compared to earlier systems on the market

Spark Detection – Advantages

spark detection and extinguishing system. spark detection – markets initiative from finnish...

Documents