A: Doan Pendleton, Vac-U-Max, says:
Eliminating uncertainty and improving productivity with engineered systems is the goal of efficient manufacturing. When a system is comprised of pre-engineered components, the optimum combination of those components oftentimes can only be proven in a full-scale test environment. By conducting a full-scale test, a manufacturer can have the confidence that the system will start delivering those reliability and productivity benefits as soon as it’s installed in their facility.
No matter the industry, the goal is to reduce waste and increase productivity. If you can add other benefits like food safety from an enclosed process, or improved ergonomics by eliminating lifting or stair climbing, or strengthening process safety when dealing with combustible dusts, many departments are satisfied, especially company management.
Certain industrial applications, which are normally lacking in waste reduction and increased productivity benefits, include direct-charge blender loading, metal powder recovery systems for additive manufacturing (AM), and spreading toppings, such as seasonings, nuts, and seeds, in the food and snack industry.
Direct-charge blender loading
Blenders and formulators — used across a wide range of industries, including food, pharmaceuticals, and chemicals — are typically difficult to load and access manually. They often require workers to climb stairs to bring ingredients up to the loading level. Sometimes pallets of 40-pound bags are forklifted for manual bag slitting and dumping by operators. Pneumatically conveying materials to the blender is safer and more efficient for everyone by eliminating all these intermediate steps, making it the preferred blender loading method.
One vacuum transfer application known as direct-charge blender loading uses a facility’s vacuum-tolerant blender or mixer as the primary receiver for a pneumatic conveying system. The bulk ingredients (and often the operators) can stay on your plant’s ground floor. Today’s V-type and double-cone blenders can reach hundreds of cubic feet in their capacities, and if the bulk material is available and ready at the pneumatic conveying system’s pickup point, blender loading can be nonstop, making it a continuous conveying process. There’s no fugitive or waste material generated by direct-charge blender loading, and the external dust collector has been eliminated. Customers in the pharmaceutical and nutraceutical industries, as well as the food and chemical industries, benefit from strict adherence to recipes and formulations for maximum product quality.
In another instance, the same general-purpose direct-charge blender loading system was adapted for use at a spray coatings manufacturing plant when increased demand required more throughput from its V-type blender. Therefore, blender loading also had to change. Direct-charge blender loading lends itself well to a sanitary system design with a bag-dump station as the pickup point.
In another instance, the same direct-charge blender loading system was adapted for use at a spray coatings manufacturing plant when increased demand required more throughput from its V-type blender. Ingredients are vacuum conveyed directly into the blender from preweighed drums, eliminating drum dumping, fugitive dusts, and stair climbing. The same vacuum system with a feed bin is then used to unload the blender at the end of the mix cycle. In this instance, blender output tripled by employing the direct-charge blender loading technique.
Metal recovery for additive manufacturing
One benefit of additive manufacturing (AM) with metal powders is the ability to reuse excess (nonfused) powders for efficient ingredient handling. The excess isn’t a waste material if reclaimed carefully and effectively. Not only are metal powders an expensive ingredient, but they’re also an ergonomic nightmare due to their high density and inhalation hazard. Another key element of AM production is time — more uptime and less downtime will increase profit margins and speed up new product delivery. Using high-vacuum and ultrasonic sieving technology will reduce that downtime factor and return predictable, usable metal powder to the warehouse for future builds. Metal powder recovery systems use vacuum to extract powder directly from 3D printers, dryer trays, or other containers, and convey the powder to a vacuum receiver that discharges into a sieve. Good powder then discharges from the sieve into a pail, drum, or other intermediate bulk container for reuse. Some metal powders are combustible, reactive, or both, requiring the recovery process to take place within an inert environment.
In one adapted system, an AM equipment manufacturer wanted to meter the good powder for reuse into the same containers in which the powder arrived. The containers hold approximately 22 pounds of material, making them manageable for workers to manipulate during the loading process and minimizing ergonomic hazards. Reusing the containers also allows the AM manufacturer to reseal the material in the container with desiccant packs, reducing the drying cycle frequency needed for hygroscopic metal powders that absorb moisture from ambient air.
This powder recovery process was accomplished mostly with precision programming of the conveying cycle in concert with material monitoring using a level control and a scale that connect into the metal powder recovery system’s control panel.
Topping spreader for food industry
During a recent multifaceted retrofit to increase efficiency and safety of a customer’s bakery process, one of the goals was to provide the bagel maker with a fully enclosed automated spreader-feeder and reclaim system that would integrate with a new 10-foot-wide seed spreader installation.
The problem with using vacuum conveyors in the topping process and the reason why most industrial bakers still use manual methods is that most vacuum conveying systems end at the discharge point, with no solution for auger distribution. As such, vacuum conveyors that deliver material to dispensing equipment are usually located directly above the topping equipment (such as spreaders, dispensers, depositors, and applicators), resulting in dry materials congregating in the topping equipment’s center. This requires a full-time laborer to manually smooth this material to the furthest ends of the topping equipment for the duration of the process to ensure even distribution.
Prior to the bagel line retrofit, workers would fill buckets from seed bags, climb up five or six stairs onto a platform, and spill buckets into the hopper above the topping equipment until it was full. Once the line started, the worker would remain at the station to monitor when the equipment needed refilling with reclaimed material.
Seeds that didn’t land on the bagels fell through a wire mesh conveyor onto a belt conveyor beneath it, and that conveyor dumped seeds into a bin below for reuse. Like most manual handling tasks, the repetitive manual loading of dry topping dispensing equipment posed ergonomic, repetitive-motion, and fall hazards.
Manual material handling is a known occupational hazard, and the open-air nature of manual dry material transfer exposes ingredients to humidity; moisture from other equipment; flour in the air or dust; and other physical, biological, and chemical hazards. These hazards inherently make manual handling a critical control point (CCP) as addressed in the Food Safety Modernization Act.
Now, instead of using bags of seeds and buckets to load the spreader manually, the industrial bakery wheels a large tub filled with seeds to the line, inserts the vacuum conveying pickup wand into the tub, and closes the lid. The system sucks the seeds out of the tub and into the distribution screw that uniformly fills the spreader hopper. The seeds that don’t land on bagels drop below into a closed vacuum conveying system where another conveying hose pulls the seeds back into the system, repeating the process over and over again. The system also provided some cost-saving fringe benefits in terms of labor and administrative expenses. Significant annual savings are achieved with the system by not having to station one to two workers there for the duration of the process because the new system is more of a set it up and walk away scenario.
Safety hazards and CCPs require preventive controls and documentation, which add administrative and training costs. So, whenever an organization can eliminate a hazard altogether, it bolsters the operation’s bottom line.
Vac-U-Max, Belleville, NJ, designs and manufactures bulk material handling systems and support equipment for dry material conveying, weighing, and batching.