Selection of heat exchanger materials and manufacturers
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Dear experts, our company needs a flue gas heat exchanger. The flue gas in question comes from a power plant after desulfurization and dust removal; its temperature is 80°C, and the water vapor content is 18% by volume. We aim to cool this gas to 45°C (below the dew point), at which point some water will condense. The pH value of the condensed water is between 5 and 7. I consulted a heat exchanger company earlier; the type of heat exchanger they offered was a shell-and-tube heat exchanger, using steel-aluminum composite heat exchange tubes. Cooling water flows inside the tubes, while flue gas flows outside them. The main tubes are made of ordinary stainless steel, and the fins are made of rolled, corrosion-resistant aluminum alloy, with a corrosion-resistant coating applied to them. I’m not sure whether such materials can prevent corrosion over the long term. Also, what are some good methods for cleaning scale? If fluoroplastic heat exchangers are used, it is said that fluoroplastics are relatively expensive; do you think it’s necessary? Which manufacturers in our country are capable of producing high-quality large-scale heat exchangers? I would be very grateful if everyone could give some recommendations!
The base tube is made of ordinary stainless steel, while the fins are made of rolled anti-corrosion aluminum alloy; an anti-corrosion coating is applied to the fins. === This design is incorrect. Corrosion prevention can easily lead to low heat exchange efficiency ； And once the anti-corrosion layer is damaged during transportation and installation, aluminum corrodes easily
If fluoroplastic heat exchangers are used, it is said that fluoroplastics are relatively expensive; do you think it’s necessary? === This design is also clearly flawed, as the heat exchange efficiency is very poor
Hello, what is the corrosion resistance of the 6000 series aluminum alloys? If such a design is not feasible, what would be a more economical material to use? Can ND steel be used? Thank you!
Power plants are now starting to use fluoroplastic heat exchangers, with heat exchange tube bundles of 5mm/0.5mm thickness; there are many such tubes, and it is said that they can achieve a heat transfer coefficient similar to that of ordinary steel. What are your thoughts on this? Thank you!
You can take a look at the new glass plate heat exchangers produced by Luoyang Ruichang Petrochemical. . . . Suitable for use in acidic atmospheres at temperatures below the dew point.
You could consider using a graphite heat exchanger; the temperature isn’t high, so there’s no problem
Smoke recovers – we specialize in this. Based on your requirements, the smoke recycler is made entirely of 304 stainless steel; below are several sample products we have created. http://www.gzqingli.com/upfile/2015/07/20150714135207_798.jpg http://www.gzqingli.com/upfile/2015/10/20151008162301_710.jpg http://www.gzqingli.com/upfile/2015/07/20150714135836_438.jpg
For the recovery of waste heat from flue gas, I still recommend fluoroplastics. If the dust content is not high, they can be placed directly in the flue, which eliminates the need for a casing and thus reduces costs; corrosion is basically not a concern with fluoroplastics. If the operating conditions are stable, the service life is also relatively long.
Hello, has the issue with flue gas heat exchange been resolved? I have a few questions I’d like to ask
For flue gas heat exchangers, aren’t finned tubes better?