Acid gas, waste heat boiler

[wdwodicka]

I've got some waste gas from an incinerator, at 1800 F, and I want to run it through a heat exchanger to make steam - but the waste gas contains about 700 ppmv of HCl, so I'm assuming I'll need Hastelloy C or something similar.

Right now, the gas is fed directly into a quench tank, then into a caustic scrubber to eliminate the HCl before discharge to the atmosphere. I'd like to grab some heat from the waste gas before it hits the quench.

Anybody know of a good vendor for this?

 

[EdStainless]

There are a number of fabricators building recuperators or waste heat recovery units.
Often these units are built using two or three different alloys.
A high temp grade for the hot part, common SS for the middle, and a Ni alloy for the cold section.

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Rust never sleeps
Neither should your protection

http://www.trent-tube.com/contact/Tech_Assist.cfm

 

[ApC2Kp]

wdwodicka,

Your temperature sounds like it could be feasible to make steam, and yet keep outlet temperatures above the dewpoint where corrosion gets severe (250 F - 350F ?). You will need to specify mass flows and heat rate to vendors.

Try contacting

http://www.technotherm-usa.com

WHB firetube used w/ SO2 furnaces

http://www.bdheat.com

http://www.kentube.com

(heat recovery exchangers - see below)

If your commercial insurance agency will agree to classify the unit as a heat recovery exchanger to ASME Sec VIII, you might avoid some of the paperwork, registration, and annual inspections (extend to 2 year inspection?) compared to having a fired boiler stamped and registered ASME Sec I. If you would use the steam pressure at 15 psig max. for heating purposes, or use unit for hot water 160 psig maximum, then you could avoid ASME Section I Code design, fabrication, and registration requirements. You will still want to include controls and safety measures (relief valve, water level controls) similar to the ASME Section I Code.

For smaller heat rates the most economical benefit might be heat recovery for heating boiler water. Be careful of corrosion problems in condensing economizers. Some porcelain coated condensing economizers have been OK where the maximum temperatures were not as hot as your conditions. There are high alloy condensing economizers used, where the heat recovery was financially justified with the offset cost of purchased energy.