Viewing Window for Engine Test Cells
Viewing Window for Engine Test Cells
(OP)
Dear Experts,
This is quite an unusual question but I was wondering whether there are any particular kind of glass that is normally used for engine test cell windows. The engine test cell at my work place is currently being upgraded and we are looking to use glass window for viewing. I am looking at using bullet proof glass for safety reasons but I think it may be a bit of overkill. I will be doing some calculations on energy from connecting rod or fly wheel falling of the engine and possibly hitting the window. Are there any other calculations I should consider? What would be really useful if you could please provide an idea of which type of glass is normally used and/or any methods used to specify a particular glass for the application?
Thank you.
This is quite an unusual question but I was wondering whether there are any particular kind of glass that is normally used for engine test cell windows. The engine test cell at my work place is currently being upgraded and we are looking to use glass window for viewing. I am looking at using bullet proof glass for safety reasons but I think it may be a bit of overkill. I will be doing some calculations on energy from connecting rod or fly wheel falling of the engine and possibly hitting the window. Are there any other calculations I should consider? What would be really useful if you could please provide an idea of which type of glass is normally used and/or any methods used to specify a particular glass for the application?
Thank you.





RE: Viewing Window for Engine Test Cells
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The Help for this program was created in Windows Help format, which depends on a feature that isn't included in this version of Windows.
RE: Viewing Window for Engine Test Cells
RE: Viewing Window for Engine Test Cells
All the cells I've seen had viewing windows at the front of the engine for that reason. Usually glass with mesh.
RE: Viewing Window for Engine Test Cells
I was running a NATO certification test cycle on a 700 HP engine and a visiting dignitary opened the test cell door and stood right next to the engine running full bore. Fortunately nothing happened but I nearly had a heart attack.
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The Help for this program was created in Windows Help format, which depends on a feature that isn't included in this version of Windows.
RE: Viewing Window for Engine Test Cells
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: Viewing Window for Engine Test Cells
RE: Viewing Window for Engine Test Cells
I agree with what GregLocock said about fire related hazards, especially with confined test cell spaces. Many years ago I recall doing some dyno work with a large diesel engine that used a prototype 1500bar CR injection system. The engine produced quite a bit of vibration, and the high-pressure fuel line connections occasionally sprang leaks during running. In just the blink of an eye these high-pressure leaks would envelope the engine in a cloud of finely atomized diesel fuel, creating the perfect conditions for an explosion. The spray from the high-pressure leaks was so finely atomized that it was hard to see from the control station. We had to have one operator constantly watching for leaks (thru a small window) during operation, which was not an easy thing to do for a test period lasting several hours. But even if the operator saw the leak the instant it occurred, hitting the E-stop and bringing that large engine to a halt still took a couple seconds. The test cell was sealed except for two large ducts that circulated outside air thru the test cell by fan. Thankfully we never experienced a test cell fire or explosion, but I still wonder if the barrier (window and wall) between the test cell and the operator station would have withstood the pressure from an explosion.
Engine test cells located inside a building structure might need to be fire rated for an extended period of time, possibly an hour or more. Thus a fire rated window material would be required, which means some type of glass such as this.
Hope that helps.
Terry
RE: Viewing Window for Engine Test Cells
Video cameras and monitors are cheap enough, and they can't transmit kinetic energy.
for a few bucks more you can get remote pan and zoom units.
For a full fail-safe window, some basic durable heat resistant glass with some thick steel plate on the inside that can be swung out of the way if something destroys all the cameras.
(if all the cameras were destroyed, would YOU open the shield?)
cheers
Jay
Jay Maechtlen
http://www.laserpubs.com/techcomm
RE: Viewing Window for Engine Test Cells
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: Viewing Window for Engine Test Cells
Other "color" filters for other kinds of events?
Jay Maechtlen
http://www.laserpubs.com/techcomm
RE: Viewing Window for Engine Test Cells
RE: Viewing Window for Engine Test Cells
Here's a link to a manufacturer of engine test cells for hazardous applications that has a couple videos discussing how they deal with problems like fire, noise, explosion, etc.
The safest approach would be to eliminate the window, move the operator station to a location away from the test cell, and install a system of sensors and cameras that the operator can use to monitor the test cell. However, this would also likely cost more money than the OP is willing to spend on this test cell upgrade.
Lastly, as romke suggested you can try contacting a manufacturer of ballistic/explosion/fire resistant glass such as this: http://www.fireglass.com/glass/pyrostop/Pyrostop_B... . But due to liability concerns, all they will likely say to you is refer to the data we have published for the material.
RE: Viewing Window for Engine Test Cells
Windows should be placed out of the plane of rotation of major equipment. If this is not possible, then a ballistic analysis should be performed by a qualified person to determine the necessary impact resistance for the window, and the window designed to suit.
Windows should have internal pressure rating equal to that of the test cell walls and doors. Test cells designed for gaseous or volatile fuels should have pressure limiting features, with (usually) one "weak" wall that vents to a safe outside area. See NFPA 68.
Wire glass windows in fire-rated walls are quite limited in allowable size (100 in^2). Large view windows can be made of fire-resistant glass, but this material is very expensive, and probably the assembly would not be UL rated. Also fire-resistant glass is "one time use", it must be replaced in event of a fire. Therefore it is common to install a non-fire-rated glass window but to protect the window on the test cell side with an automatic closing fire shutter. Usually the shutter has thermal fuses on both sides of the wall. The shutter can be closed by hand for privacy.
Good sound transmission resistance usually requires at least two "lights" (glass panels) separated by an air space. Typical construction for a vehicle engine test cell might be 1-1/4" thick laminated safety glass test cell side, with 1/4" thick LSG operator side. This construction will obtain pressure rating of 100-144 psf depending upon window size.
David P
RE: Viewing Window for Engine Test Cells
I worked with some people recently on a test cell (not engine) where they handle highly flammable fluids at high pressure. They installed a high pressure water fire suppression system. They deliver water and nitrogen to the heads at about 5,000psi and create a fog. I watched them put out test fires, and leave no puddles in the room. They knock the oxygen level back to about 12% and absorb heat with the mist.
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P.E. Metallurgy, Plymouth Tube