Hydro shield or water curtain nozzle/monitor

[dirkjaniak]

Hey Forum,

I need your help. I was looking for a piece of equipment we used to use in Germany for exposure protection- a so called "Hydroshield". It is a simple way to protected exposures such as houses or in case of a gas release. I searched my a.. off on the internet to come up with a manufacturer or supplier that has that kind of nozzle in Canada or the US but I could not find anything!! Maybe I'm just using the wrong search word :(
Does anyone of you know that kind of equipment or has one in use??
If yes, could you please give me the name of the supplier or manufacturer!!

I attached some pics so that you get an idea what I'm talking about.

Thanks for your help,

DJ

[FFGrump]

We used to have them we called them exposure appliances, or exposure nozzles. They were pretty much done away with here 10 or so years ago. I read a study that showed that in a real exposure situation between two houses they would only absorb abour 15-20% of the radient heat. A far more affective way would be to use a ground monitor to coat the side of the exposure with water or a water foam mixture. The volume of water from one of these is far more effective than an exposure appliance.This is also what is called for in ICS incident management (a ground monitor) as opposed to a water stream from a exposure appliance. But if you want to look for them, try exposure nozzle, exposure appliance, or water curtain they might help you look in the right direction. Cheers.

[dirkjaniak]

Thanks FFGrump,

I'll see if I can find it now.
We are looking into ways to prevent the fire spread between houses that are build way too close. Edmonton had it's fair share of house fires lately that spread real quick to other exposures so maybe that nozzle could be used as an addition to monitors (which we already use, of course;)). I see the advantage in such a nozzle in not having to men it and put some more water in between the houses.
Can you remember the manufacturer by any chance?

DJ

[LFD_FF17]

we have one of those on one of our pumps and we call it a "water wall"

[dentedhead]

We have them on all our trucks,I am pretty sure they were made in house way before my time.It is a fairly easy fabrication.

I will double check it tonight for a better description......dont expect any pictures:stupid:

Dentedhead

[iamvff]

We have some 100mm that would work well as a water curtain!

iamvff:p

[PFD023]

.... I read a study that showed that in a real exposure situation between two houses they would only absorb abour 15-20% of the radient heat. ......

This may be the article.....http://www.fireengineering.com/display_article/344397/25/ONART/none/BRNIS/Emergency-Service-Myths:-Mistakes,-Misconceptions,-and-Misdirectio?dcmp=rss

[XTRK8]

We have some home-made versions of this style of nozzle kicking around too (38mm and 65mm). Can't say I've ever seen one put into service at a fire-scene, but some of the older (sorry, I mean "more mature") members hang on to fond memories of using these "back in the day".

They are quick to set-up (1-person can easily do it), and innexpensive. Maybe they don't work as good as a ground-monitor but in a pinch or on a tight budget, they do the trick.

At a low pressure, they work great for washing salt and sand the underide of vehicles... kinda like the underspray jets you seen in car-washes :)

[fire16]

wfrfire.com out of Calgary . has single and dual inlet units 38mm or 65mm

[dirkjaniak]

Thank you all,

I was considering building it 'cause it would be easy but after reading the article (thanks for the link PFD023) I'm thinking it could be a wast of time. There are for sure other good applications for a water wall but it seems like nobody really needs or uses one.

Maybe a modified version that also sprays water right on to the exposure ....?!

Just thinking out loud here ;)

Thanks again everybody.

DJ

[oldarffer]

We have them on all of our engines and although the nozzle itself is not very effective as intended or designed, it can be made useful. Place the appliance between the structures and tip it toward the exposure (place a piece of cribbing under the edge of it) and allow the water to hit the wall at the soffit level and run down it. Works well, give it a go.

[FFGrump]

Thanks FFGrump,

I'll see if I can find it now.
We are looking into ways to prevent the fire spread between houses that are build way too close. Edmonton had it's fair share of house fires lately that spread real quick to other exposures so maybe that nozzle could be used as an addition to monitors (which we already use, of course;)). I see the advantage in such a nozzle in not having to men it and put some more water in between the houses.
Can you remember the manufacturer by any chance?

DJ

Hi Dirk!

like the other guys have said here our exposure nozzles were also made in house, so no actual brand name that I can give you.

But I did some google-ing and you are right it is very hard to find anything about these nozzles. Eventually after trying a bunch of different terms I did come accros one from Task Force Tips (TFT). I will copy and past the link below, check them out, is this suitable for what you are talking about?

http://www.tft.com/newsite/class.asp?cls=SP_WC&itm=S-WC&gid=2&pid=1
http://www.tft.com/newsite/images/products/SP_WC/S-WC/S-WC.jpg

I hope that helps you out! Also, PFD023, that is oneof the articles that I read about them, thank you for posting the link.

[dirkjaniak]

Hey FFGrump,

thanks for the link. All though it looks like it could work, I really don't think that those are as effectiv as the "German" version 'cause they only put out 380 l/min and that seems IMHO really low. The version I mean puts out 1200 l/min at 800 KPA (that is with a 75mm Storz connector).

But again thank you for checking. I know Google can be a bitch if one doesn't have the right search word.

Thanks oldarffer for the tip. I thought if we would have to build them anyways why not with a tilt function, eh!?

Cheers,

DJ

[irsmith]

A water wall like POK Fire's http://www.pokfire.com/pdf/catalog/2008%2036.pdf item # 2238 or #2239 is quick to deploy and can function without having to staff the appliance. This is a great advantage for small rural fire departments that arrive on scene with very limited manpower. A ground monitor can also provide exposure protection without committing limited manpower resources. Depending on the size and access to the space between the fire building and the exposure either of these devices will help reduce fire spread.
POK Fire Equipment is available from morrisonfire.com

[PFD023]

Interesting that only of couple of folks considered the article posted regarding the myth that water curtains are effective in protecting exposures. I'm sure not all read the article.....but for those who did....I see some of you are still pursuing the idea of attaining one. Curious to know if you have info to the contrary on the effectiveness of the curtains?
Is the belief that these are effective tools based on studies/experience?

[dirkjaniak]

Well,
the report itself doesn't give a study to prof the authors "logic" of fire physics. As oldarffer said, you can modify the water wall nozzle (if you have one) so it sprays water on the exposure.
That way convective heat and direct fire impingement are controlled (as said in the above mentioned article) and the object receives the (hopefully sufficient) cooling.

Due to the fact that we don't have such a nozzle and because be had/have a lot of house fires with extensive fire spread I was thinking such a (modified) nozzle could be useful.

I'm also sure that my departments equipment committee not just goes and buys (builds) a hydro shield. They usually investigate the pros and cons of equipment and tests them.

So just because somebody (with all due respect to the articles author) writes it doesn't work you think we should all get rid of the nozzle??
Maybe the departments that are (still) using it have had positive experience without running a study!?
If so, I don't see a reason to dispose them.

Cheers,

DJ

[PFD023]

Not slagging anyone for using one...just wanted to hear why. The article makes some good points...but as you mentioned there are more sides to the story...and experience sometimes overweighs most things.

[FFGrump]

Not slagging anyone for using one...just wanted to hear why. The article makes some good points...but as you mentioned there are more sides to the story...and experience sometimes overweighs most things.

I'm curious too. I have only really heard negatives about them and we have had ours off the trucks for years. Even before that they were getting cobwebs from not getting used. We have had far more luck using a ground monitor for the same purpose. But thats is not to say that they couldnt work elsewhere. I think the ones that your talking about Dirk make more sense because at least they have a signifigant flow to them the ones we had used very little water and go figure they didnt do much for us!

[hmckay91]

As oldarffer said, you can modify the water wall nozzle (if you have one) so it sprays water on the exposure. That way convective heat and direct fire impingement are controlled (as said in the above mentioned article) and the object receives the (hopefully sufficient) cooling.That supports the article authors point, as designed the nozzle doesnt do what fighterfighters "believe" it does. Using it as oldarffer suggests is likely a valid technique. The only issue perhaps, is it has to be placed perfectly, if not there is a risk. If it then requires tending, why not use a nozzle you can control and adjust easier, if you have to commit manpower anyway?

Not withstanding the availability of "evidence" one way or another, it is an interesting concept. I ask myself when approaching a pressureized gas fire on the end of a line how efficient does the wide fog stream absorb the radiant heat? (100%, 50%, 30%, ?) therein lies the "logic" of the the author's fire physics.