Small steam or elec. 200¦F water heater?

[ChasBean1]

Hi all, I haven't had much luck with search engine results for what I need, which is to preheat small volumes of make-up water to 200°F. Ideally, a 3-5 gallon steam or electric heated tank (well insulated) that can maintain 200°F pretty steadily.

Don't waste your time googling for me, but if you happen to know someone's product that can fit this application, please post. Thanks! -CB

 

[EdStainless]

There are comercial water heaters that are used as boosters for sanitizing that are rated for a constant 185F output. I don't think that you will find a demand heater rated for that out put temp.
You could try Heat Transfer Products in East Freetown MA for gas fired units.

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Corrosion never sleeps, but it can be managed.

http://www.trenttube.com/Trent/tech_form.htm

 

[rmw]

Graham or Leslie make steam instant response water heaters that are capable of small flows.

rmw

 

[MintJulep]

Why wouldn't a small shell and tube HX work?

 

[ChasBean1]

The application is make-up water for humidifier reservoirs. Right now, about every hour and a half during humidification the reservoir level drops enough to cause it to fill (probably via a float). The fill volume is only about a quart. But the fill subcools the water volume in the reservoir and takes some time to heat back up and start steaming again. Meanwhile it generates a bouncy humidity profile in a critical environment area. Make-up flow is off 99% of the time and when it starts, it needs to be (ideally) 200-212°F instantaneously. I did consider the shell & tube you noted, Mint, but then I'd worry about control responses, etc.

Probably a lot of you have hot water spigots at your offices for coffee/tea, etc. These are generally adjustable up to 212°F. I've seen the Leslie "Constantemp" heater but an altered coffee water heater might be even simpler and better for this. Thanks for all responses-CB

 

[MintJulep]

Chas,

Do you have the option of altering the fill control of the existing reservoir?

Rather than dumping a bunch of cold water when a low condition is detected, allow a continuous trickle, and stop the flow on a high condition.

Small flow rate shouldn't cause significant cooling in the reservoir.

 

[quark]

You can consider thermostatic control valves by Spirax Sarco. I used them in the past with their steam nozzles for direct injection of steam. As my application was for reheating of conditioned air, I had to continuously bleed off water from the tank at a rate equal to that of steam flow. In your case this may not be the problem. They can maintain the temperature with in +/-1⁰C. You can use them for steam coils also. These valves work well as long as thermostatic fluid doesn't leak. As a note of caution, you may have to replace the capillary once a year.

Have you thought of thyristor controlled heaters or PID on/off heaters?

Regards,

 

[GenB]

An electric heater will give you the best results, you have to calc the minimum GPM needed so you can size the unit. recovery is critical in your situation.
try steamequip.com
ER

 

[GenB]

try

http://www.steamequip.com

and send an email info,
ER