Dri-Air Industries Helps Poly Clean Take "Portable" Drying to the Next Level
Unique initiative allows portable drying from inside a box truck
(Dri-Air Industries, Inc., East Windsor, CT) - Dri-Air recently completed the install of a unique and truly portable drying system. So portable that the system is mounted inside a 28-foot body truck, which can be easily driven to a customer's location.
This novel initiative was launched by Poly Clean USA LLC (polycleanusa.com), Charleston, S.C., as a spinoff of a somewhat related operation the company has been conducting since it opened its doors in 1999: a five-truck "factory on wheels" fleet that brings various optical-sorting technologies right to processors, resin companies, recyclers and compounders. For this new drying system moist resin is conveyed from the customer's facility into the portable drying system within the truck, where it is dried with conventional desiccant dryers. Once the material is dried, it is conveyed back into the customer's plant to their containers.
"The task we were given was to dry up to 1000 lb/hr of resin with a 6-hour residence time," said Charles Sears, Dri-Air president. "Normally, this would be easy with a 1000 cfm dryer and 6000-lb capacity hopper on a stand outfitted with an appropriate hopper loader."
"However, the additional stipulation was to mount all of the equipment into a truck that would not require a special license to drive," says Sears. "Obviously, standard equipment does not fit into a truck as the height of a 6000 lb capacity hopper would exceed the height of the truck."
The Dri-Air design incorporated six modified 1000-pound capacity hoppers to each process 166 pounds/hr. The six hoppers were divided into two banks of three hoppers each with a 500 cfm dryer. For an insurance factor, in case the 6- hour residence time was not adequate, a modified HPD-13 dryer was incorporated to act as a finishing hopper, which is fed from the six drying hoppers.
All of the hoppers were modified in height to fit within the 109-inch height restriction of the truck. This modification required shortening the cone section of the hopper and a special designed take off box with quick clamp access. The use of low profile, high capacity receivers on top of each hopper left a 2-inch clearance to the top of the truck. Minor changes to the dryer allows access to all filters and servicing once in the truck.
Three loading systems were used to meet the 1000-pound per requirement. The first loading system loads all six hoppers from material outside the truck. A 10 HP positive displacement pump with a 2.5 inch common material line fills the six hoppers in rotation for maximum efficiency. The system is sized to load all six hoppers in less than an hour. After three loads of material in the hoppers, the dryers can be started as part of the 6-hour residence time.
Each hopper has its own heater for accurate temperature control to maximize drying of the material. The temperatures are controlled by the master PLC that also monitors and controls the loading functions. For throughputs less than the 1000 pound per hour design, any number of hoppers can be used to maintain the proper residence time for that particular resin. Automatic air valves control the dry air flow to each hopper as they are turned on and off.
The central control panel includes a 12-inch touch screen display with an imbedded PLC for easy operator interface. The main screen depicts the entire system and the status of all of the components. To modify any parameter simply involves touching the picture of that item which brings up a screen for implementing any changes. A separate alarm screen describes the mode of failure for any alarm condition.
This project required close attention to details in order to fit all of the equipment into the small space allowed and yet be able to service each piece easily. The system is completely self sufficient with only electrical power connected to the main power panel. A compressor is included to provide the necessary compressed air.
The new drying venture is aimed at processors and resin suppliers/compounders who are dealing with either seasonal or regular problems with moisture, says Mark Richards, who co-owns Poly-Clean. These clients may even have their own drying capacity...just not enough. "Our business is to go to plants where material is out of spec for one reason or another and help get it ready for processing," says Richards. "We called a lot of suppliers, but we needed someone who was willing to think 'inside the box,'" says Richards, referring to the 8-ft wide x 9-ft tall x 28-ft long dimensions of the truck. Richards says Poly Clean has already signed up a client for the drying service-a 7 million lb/yr project-and has several others in the wings. He expects to expand the service beyond one truck as the business grows.
About Dri-AIr
Since 1974 Dri-Air has been the Industry leader in proven desiccant dryer technology, offering the highest quality at competitive pricing. Our plastics drying and loading systems offer a full range of solutions for drying plastic resins, mixing, blending and conveying virgin, regrind and plastic colorants. We offer advanced microprocessor control, stainless steel insulated hoppers, closed-loop loading systems and full-flo electric dryer valves. Our constant attention to detail and incredible response time has helped us sell thousands of drying systems worldwide. From 1 pound to 1,000 pounds per hour, we offer solutions to a wide range of industries from simple solutions to complex custom applications.
Charlie Sears
Dri-Air Industries
860-627-5110
csears@dri-air.com
