Firestone air springs, available from Air Springs Supply are recommended for powder processing applications for their ability to cope with harsh conditions.
Powder handling tasks typically impose rigorous demands upon actuators and isolators used in materials handling systems. In addition to withstanding the dust, abrasion and fine particles that can damage the rods and seals of conventional cylinders and risk production stoppages, they must be able to cycle rapidly in actuation roles as well as control high levels of noise, vibration and harshness (NVH) in isolation roles.
James Maslin, National Sales and Marketing Manager for Air Springs Supply explains that fewer moving parts and reduced complexity result in less wear and more reliability, making air spring actuators and isolators ideal for powder processors. Firestone air springs, Airstrokes and Airmounts are particularly appropriate in situations requiring rapid cycling, high reliability and minimal susceptibility to wear in grimy industrial situations.
Air Springs Supply and Firestone engineers are expanding the application scope for flexible-wall, bellows-type Airstroke and Airmount air cylinders. These air springs operate without rods or seals, can be small enough to fit in the palm of a hand, or more than a metre across and capable of producing 40,000kg of force.
Airmount air cylinders were supplied for a powder handling project at Semi-Bulk Systems Inc, a US company that manufactures state-of-the-art equipment and containers for unloading, batching and processing bulk quantities of fine-dry powders for food and beverage, dairy, and industrial and chemical products, including paint and paper components.
Semi-Bulk Systems employed a system for unloading vinyl bags of powder weighing 400-3800kg, wherein the product was discharged through a hole in the bottom of the bag. Since the product came out in big slugs, rather than evenly and smoothly, Semi-Bulk's solution was to blow air through the powder to break it up and make it fluffy to allow smooth discharge through a 100mm hole at the bottom of the container.
The container allowed for controlled flow of material through its use of a support stand with a hinged deck beneath which an Airmount isolator was inflated at about 1 bar. The stand supported the container at its corners with hooks, allowing gravity to dispense the powder through the hole in the container floor.
Semi-Bulk's system positioned the container on the deck and allowed it to empty through gravity. When the powder got down to about 25% in the container, the pressure in the Airmount was greater than the weight of the container, causing the hinged deck to rise and tilting the container so the remaining powder flowed evenly toward the discharge port.
Semi-Bulk used double convoluted Airmounts for smaller bags and triple convoluted Model 38s for larger bags, with the Airmounts featuring a maximum diameter of 950mm and load capacity of 40,000kg at 5.5 bar and maximum stroke of 350mm. Semi-Bulk's process also included a smaller Model 16 Airmount that inflated when the hinged deck tilted, activating an air piston vibrator that vibrated against the container base and helped dispense the powder further.
Key advantages of Airmounts over air cylinders:
- One Airmount replaces two conventional cylinders
- Eliminates need for lubrication or maintenance as required by conventional air cylinders
- No guides and seals in Airmounts makes them ideal for rigorous production environments
- Suitable for metal stamping, vibrating screen and conveyor applications, labelling, sealing and packaging tasks
- Isolates equipment including compressors, computers, generators and refrigeration and air-conditioning equipment