• Fans and stacks shall be designed and constructed so that the gas stream only contacts solid FRP surfaces. Steel fasteners within the gas contact area will be stainless steel and encapsulated with a minimum of 0.1875″ (3 mm) of FRP lay-up. Fan shafts will be fully protected from exposure to the gas stream by FRP shaft sleeves. The fan shall be constructed per AMCA Standards 99. The maintenance of the fans will allow motor change outs and/or belt changes without maintenance personnel having to be exposed to toxic air stream areas or the handling of impellers within a toxic air stream area. The fan arrangement will be based on AMCA 99 and will be either AMCA arrangement #1,4,8,9 or 10 as indicated on the document schedules.
Acceptable Manufacturers: Plasticair Inc.
• The performance ratings are to be in accordance with AMCA standard 210. The selected fan must be licensed to bear the AMCA Seal for Air and Sound.
• The impeller is to be of a high efficiency backward inclined design. The materials of construction will be vinyl ester resin (premium quality 0-25 flame spread) and reinforcing glass throughout. The method of construction is to be hand lay-up only. The entire surface of the impeller exposed to the gas stream will be complete with a resin-rich corrosion barrier consisting of C-veil and a smooth finish. The shaft is to be attached to the back -plate of the impeller by way of a taper lock bushing and a one piece cast sprocket hub. The entire shaft attachment assembly is to be completely covered with a minimum 0.25″(6 mm) of FRP lay-up.
• The fan housing is to be solid FRP throughout. The outlet and inlet flanges are to be of heavy industrial quality. All flanges are to have factory flat finishes. The materials of construction will be vinyl ester resin (premium quality premium quality 0-25 flame spread) and reinforcing glass throughout. The entire surface exposed to the gas stream will be complete with a resin-rich corrosion barrier consisting of C-veil and a smooth finish. The outer surface of the housing will be of a heavy UV stabilized gel coat. The housing shall include a machined Teflon shaft seal to limit gas leakage.
Fan Outlet Nozzle and Wind-band
• The fan discharge will be fitted with a UV stabilized FRP exit nozzle and attached conical FRP wind-band. The nozzle assembly will be designed to dilute outside air into the exhaust gas stream up to 200%. Dilution numbers are based on independent third party testing performed in still air. The nozzle assembly will be supported by the fan housing without the need for guy wires or additional supports and the Manufacturer will warranty the stack against failure due to rust for 25 years. The outer surface of the nozzle and wind-band will be UV stabilized gel coat. Manufacturer will provide and honor a 25 year full replacement warranty against failure due to rust.
Steel Fan Base
• The fan base is to be of a heavy-duty industrial quality design to minimize vibration and to ensure long life. The bearing shaft pedestal is to be constructed of heavy gauge steel. The fan base is to be coated as follows. Sandblasted to white and epoxy coated with 10-12 mils of UV stable epoxy or coated with 3/16” UV stable FRP.
• Bearings are to be solid pillow block, self-aligning type. The bearings are to be rated and designed for a minimum L-10 life of 200,000 hours. The bearings are to be located out of the air stream. The method of lubrication will be grease.
• Fan shaft will be 1045 carbon steel complete with the correct keyways to accept V-belt drive selections. The diameter of the shaft shall be sized to ensure that the critical speed of the fan is at least 25% above the fan operating speed. The impeller side of the shaft shall be complete with an FRP shaft sleeve, which is bonded to the back-plate of the impeller and protrudes through the housing. The outside diameter of the sleeve is machined to provide a minimum clearance gap with the Teflon shaft seal.
• Motor will be a foot mounted totally enclosed fan cooled motor with a 1.15 service factor.
• V-belt drive shall be sized with a safety factor of 1.5 times the motor horsepower. An adjustable base will be provided under the motor to permit setting the belt tension.
• Weatherproof FRP guards complying with the OSHA standard will protect the shaft and v-belt drive.
Balancing And Testing
• Balancing of the impeller shall be achieved only with the use of the identical material used to fabricate the impeller. Balancing shall be in accordance with ASTM D-4167. The fan shall be test run at operating speed and not shipped until vibration readings are within acceptable limits.
• The materials of construction will be as per the attached schedule. Dampers, controls and other options will be as detailed in the schedule.
• The supplier shall warrant that all system components shall be free from defects in materials and workmanship for a period of 15 months from date shipped or 12 months from equipment start-up, whichever occurs first. Extended warranty on induction stack to 25 years from date of purchase.