Pipe shield to prevent burns from uninsulated pipe

[MinnesotaSlinger]

On my heat exchanger project, I will have some length of condensate piping that should not be insulated in order to prevent subcooling of condensate before steam trap. However, I want to install a personnel safety shield around the pipe to prevent personnel from burning themselves on very hot piping. I've seen what I'm talking about before---basically, a perforated or mesh sort of curved sheet metal that is clamped on to and surrounds a pipe an inch or so from its surface. However, I'm not sure what it's called or who would sell it. I understand this forum isn't for promoting products although if someone can point me in the right direction, I'd appreciate it.

 

[KevinNZ]

We just completed a project we had a heat shield may from mesh, treaded bar and pipe clamps.

Kevin

 

[Compositepro]

Perhaps the term you are looking for is "expanded metal mesh".

 

[MikeHalloran]

Expanded mesh surrounding a hot pipe will equilibrate to a surface temperature very near that of the hot pipe, thanks to conduction through the supports and direct radiation from the hot pipe.

It therefore does almost nothing to protect personnel from hot surface burns, unless there is a substantial flow of temperate air over the assembly.

WRT to the velocity of the temperate air required, I'm guessing it's about 100 mi/hr, based on experience aboard a yacht, where the gas turbine's exhaust pipe was insulated with some self-supporting metal mesh type stuff that had been used with reported good results on the owner's race cars. In the gentle breezes found in an engineroom, the stuff didn't do squat.

( Said owner had a set of insulating blankets measured and made overnight. I was in the insulating blanket business at the time, and couldn't have produced them in a week. I was duly impressed. )




Mike Halloran
Pembroke Pines, FL, USA

 

[MortenA]

If you cant find a suited product maybe i could recommend just putting up a railing next to the pipe with black and yellow stripes on them to warn persons to keep a distance?

I tried to google around a little but found no refernces. Just a few mm. of neoprene would lower the skin tempearture significantly - but would also reduce the cooling.

 

[KvdW]

Perforated plate personal protection works for me in an outdoor application for piping with process temperature of 150 °C. The perforated plate has supporting rings (0.5 to 1 m apart) which are on small strip legs attached to the process pipe. The conduction through these small strips is clearly outweighted by the large surface of perforated plate in the outdoor air.

 

[LittleInch]

KvdW - for interest what is the size of the line this is protecting? To me the issue is how far beyond the OD of the pipe does the shielding need to be to avoid heating up due to convection, radiation and conduction through the attachments. My guess is that you're looking at least double OD depending on the temperature and size or perhaps 3 x OD for small OD. The amount of convection air available clearly has an issue as well so you may need more space clearenece inside versus outside.

A bit of trial and temperature measurements probably needed here....

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[KvdW]

The pipes on the picture are DN250. The same protection is used on lines DN400 and DN600. In all cases, the distance between pipe wall and perforated plate is only a few centimeters.

 

[racookpe1978]

It could work, but keep the "mass" of the perforated plate mesh as small as possible, and the "hole area/total area" as large as possible while making the assembly "stiff" enough to prevent accidental pipe contact.

For example, 1 mm thick wire as the mesh, with 30 mm - 50 mm "holes" about 40 to 60 mm away from the pipe. Could even be 75 mm to 105 mm away.

You're ONLY trying to prevent accidental contact with the pipe by a person's hand or arm or leg.