I am re-installing ducting and dedicated exhaust fans to the vent ports of an industrial tunnel washer (a washing machine on serious steroids). There will be three headers and dedicated exhaust fans for the three different process zones (wash, bleach and rinse). The air in all three zones will be humid from water temperatures around 165 F in the hottest wash zones down to 110 F in the rinse zone. The air from the wash zone will have some alkali(sodium hydroxide) carryover. The bleach zone will have either sodium hypochlorite(chlorine bleach) or hydrogen peroxide carryover. And the rinse zone will be basically chemical free. Keep in mind, the entire machine is fabricated of stainless steel, so none of the chemical concentrations are so high as to be detrimental to the machine.
The original "ducting" installation was of schedule 40 CPVC and had more than 50 ft of horizontal run before being vented out the side of the building. In the original forced exhaust installation, the inline exhaust fans failed frequently due to the high humidity. Also, due to the high temperatures, the "ducting" sagged and created low points in which condensed water would accumulate....adding weight to an already sagging exhaust "duct".
I intend on demolishing and rebuilding this poorly designed system. I will go vertical and through the roof which is only 4 feet above the machine with proper roof penetrations. I will build and install new exhaust ducting headers with a dedicated exhaust blower for each zone. I have found a fan manufacturer that can provide exhaust fans for the application. I do not have an answer for what type of ducting is best.
I would like to hear from you your recommendation on the ducting material. There will be some horizontal runs (15 ft maximum in wash zone) as well concerns on corrosion resistance to water vapor and chemicals.
Again, chemical concentrations are low but not dismissable and temperatures will need to be taken into consideration also.
Thank you in advance.
Matt Merrick
Chief Engineer
The original "ducting" installation was of schedule 40 CPVC and had more than 50 ft of horizontal run before being vented out the side of the building. In the original forced exhaust installation, the inline exhaust fans failed frequently due to the high humidity. Also, due to the high temperatures, the "ducting" sagged and created low points in which condensed water would accumulate....adding weight to an already sagging exhaust "duct".
I intend on demolishing and rebuilding this poorly designed system. I will go vertical and through the roof which is only 4 feet above the machine with proper roof penetrations. I will build and install new exhaust ducting headers with a dedicated exhaust blower for each zone. I have found a fan manufacturer that can provide exhaust fans for the application. I do not have an answer for what type of ducting is best.
I would like to hear from you your recommendation on the ducting material. There will be some horizontal runs (15 ft maximum in wash zone) as well concerns on corrosion resistance to water vapor and chemicals.
Again, chemical concentrations are low but not dismissable and temperatures will need to be taken into consideration also.
Thank you in advance.
Matt Merrick
Chief Engineer
