The best AFD for a warehouse cardboard conveyor

[kurnal]

Hi
I am looking for a suitable fire detection system to cover a high speed  (>50m minute)  conveyor system that runs throughout a warehouse collecting waste cardboard cartons and possibly other packaging and ships it to the compactor. It will pass through at least 2 compartment walls on its travels,  with a suitable break and  be fire stopped. The warehouse has VESDA and sprinklers so the need is simply to detect a fire on the moving conveyor and to  stop it immediatey to allow the vesda and sprinklers to do their job. Probably also linking into the alarm system to get some addressable confirmation of the location from the conveyor system as well.

Quality standards on purchasing should ensure that the cardboard waste is 99% heavy corrugated cardboard but I dont want to rely on that always being the case- papers, plasics, bubble wrap may creep in by default.

The options appear to be line heat detectors- analogue or digital but I want to catch a fire early and with a fast moving conveyor without a heat collecting canopy ( effect on sprinklers) think this may not be effective, flame detectors - but again the fast movement may be a problem- it may be gone before it flickers, infrared- these may also have some benefit in picking up overheated bearings and friction problems at an early stage or finally aspirating systems.

Has anybody any advice  on this or any other aspects I should consider please?
Thanks- and have a great Christmas!

[Apollo_SG]

your request is very strange.

(Admin edit - Apollo_SG, please don't make unsubstanciated claims about partucular products, that was a brand name you used, not a generic term) oops I mean high sensitivity smoke detection or HSSD is an aspirating detection system. it does not protect anything. it merely detect. i can't imagine a line detector will work better than HSSD.

you could consider a UV/ IR flame detector for that matter. these pick up the wavelets from the fire but usually a direct vision is necessary. again that is just a detector, and probably a quick draw McGraw. alternatively you can consider the new Video Smoke Detectin system that uses markrov model to distinguish betw frames and figure out the probability of fire (smoke/ flame)

if you r worried that the sprinklers may not b activated rapidly, you may need a drencher / deluge system.

hope I did not get this wrongly.

[messy]

How about the CCTV detection systems. Frankly I know little about them, but they have been mentioned here before including when considering AFD in a waste transfer station which had similar operational difficulties as you describe

[jasper]

messy beat me to it; I remember seeing something about cctv detection systems which look a good idea and suitable for your application, I will have a dig and see if I can find who does them.
p.s. what method of firestopping are they using for the firebreaks? only reason why I ask is it is virtually impossible to use intumescents etc. cos of the shape, but recently I have seen sprinklers used above the opening between the compartments

[Ashley Wood]

The problem here is not the detecting of an incident but the speed of responce. I have just looked at something similar but not with a spead of 50m per min,. When engineering the system you need to detect 'up wind' so to speak, and extinguish 'down wind'. This is due to the time lag between detecting and activation. There is a very fast device on the market called 'Fireeye' or it may be 'Fireray', it will detect a spark traveling at 1000 feet per second. Very good but expensive kit. It is used in any application where it is a requirement to detect quick and fire a system to prevent an explosion i.e dust extract ducts etc. For the application I recently did, I designed a system using UV/IR sensors above the opening and before the opening. This was my 'up wind' detection. on the 'Down wind' side I have 2 'wet zones'. Each uses a range of high flow high pressure water mist nozzles. The idea is to damp down the fire load in the first zone and extinguish it in the second zone. The type of fire load would determin the type of nozzles used etc.

Hope this helps?

Ashley

[Chris Houston]

Just some suggestions:

Perhaps the fastest fire detectors would be humans.

Perhaps the best thing would be for the conveyors to keep moving to get the fire outside the building?

Maybe, maybe not, just some ideas, hard to suggest when I've not seen the place.

Maybe ask a newspaper printing place what they do.

Maybe focus on eliminating ignition risks.

[kurnal]

Thanks for your replies so far.
And sorry for any confusion- I do tend to be a little careless wih my terminology sometimes- but aspirating detection systems I always tend to wrongly call a vesda - just like I call my dyson a hoover........
I stand corrected.

First things first- this is a big warehouse and is absolutely critical to business continuity- no warehouse no business. The place is 400m long and racked out end to end- goods come in in cardboard boxes and are first of all loaded into the fairly high racks using fork trucks - then on a later shift  unpacked and  sorted -  there is a lot of waste cardboard which is compacted in the same building but in a seperate compartment.
The building has L1 detection using HSSD systems and ESFR sprinklers. And a compartment wall dividing it in two.
We are currently speccing the conveyor and will go as far as we can to eliminate fire risk- and have tried to think about static, friction, maintenance, foreign bodies, overloading etc. and maintenance, thermographic testing etc.

But the thing runs 400m through the warehouse  and will carry a lot of cardboard- even the cardboard has some value in the volumes we are looking at. So we want to keep it dry if possible as shipping wet cardboard out increases costs even further.    The volume means we need the conveyor to move quickly.

We think we have got accidental fire risks reasonably minimised but looking at case histories there will always be a risk of arson and the potential is huge. My worst fear is that a small fire started on the conveyor will be fanned by the movement but will be moving too fast to oprate a sprinkler head, it will eventually be picked up by the  aspirating heads at ceiling level and this will stop the conveyor. But it may operate numerous aspirating heads and confuse security staff who will think we have multi seated fires and not know where to send the fire wardens to investigate. And then if the fire passes a compartment wall before it is detected ..........

We will have fire points at regular intervals and once the conveyor stops the ESFR system will do its job- but I would like to detect any fire on the conveyor at its earliest  possible stages for intervention by humans or by the ESFR system.

Hope this makes a bit more sense now and thanks for the suggestions so far.