Issue link: https://www.e-digitaleditions.com/i/1344205
28 / March 2021 powderbulk.com Designing conveyors for safety Because increased safety is a major factor in compa- nies investing in vacuum conveying systems, vacuum conveyor manufacturers are engineering innovative systems with safety in mind. Even with the most sophisticated vacuum conveying systems, equip- ment that's located out of reach still poses hazards for operators who need to clean or service the vacuum con- veying equipment that's permanently installed above process machinery. Vacuum conveyors mounted on a column lift device and mobile vacuum conveyors are complete conveying systems that raise and lower vacuum receivers in order to load mixers, reactors, and other process equipment and also bring the vacuum receivers back down to ground level for cleaning or sanitizing. A vacuum conveyor mounted on a column lift device, as shown in Figure 2, uses an electric lift mech- anism with a remote device, controlled by an operator standing a safe distance away, to raise and lower a vacuum receiver above mixers, blenders, reactors, and other process vessels with fill ports 15 feet or more above the floor. This conveying system that's on a col- Maintaining sanitation Vacuum conveying is by far the most hygienic con- veying method for dry bulk powders and solids. The inherent nature of a fully enclosed vacuum conveying system prevents loose powder and dust from becoming airborne, creating an all-around cleaner and safer envi- ronment. The vacuum conveyor's enclosed nature also assists in compliance with the FDA's Food Safety Man- agement standards by preventing both intentional and unintentional food contamination events. When production throughput demands a high cleanliness level but using minimal labor and time, clean-in-place (CIP) equipment can eliminate hours of downtime. Cleaning downtime can be devastating to a company — sometimes taking 1 to 2 days to tear equip- ment down and clean it. CIP is a procedure designed to clean all or parts of a process system without needing to completely disassemble or move equipment. CIP is the strategic placement of spray balls or nozzles within a vessel that circulate water and cleaning solutions. This procedure is automatic and has consistent performance. Although CIP has been around for a while, it's still a leading-edge technology that's gaining traction in the food, pharmaceutical, nutraceutical, and cosmetics industries — so much so that the acronym is being used like a verb these days with customers saying they need "CIPable equipment." In CIP vacuum conveying systems, operators remove filter elements and replace them with insertable spray ball assemblies for clean- ing, saving on downtime and making the task safer for workers. Good sanitary vacuum conveyor design includes a package of simulated spray ball positioning and surface coverage documentation to ensure the noz- zle's spray pattern reaches all parts of the equipment's interior surface. For example, when a nutraceutical beverage pro- ducer landed a large contract, it needed to increase throughput and reduce the 8-hour cleaning cycle that occurred between batches in order to meet demand. To achieve this, the beverage producer replaced its 90-cubic-foot mixer with a 160-cubic-foot CIP mixer and added a vacuum conveying system equipped with a CIP vacuum receiver and CIP bag-dump station. The larger mixer replacement allowed the company to increase its material mixing capacity, and the CIP equipment reduced sanitation time from 8 to 1.75 hours, giving the company an additional 6.25 hours of production time and reduced labor costs every day. The CIP system also averted the need to develop a con- fined-space plan with the new larger equipment since the sanitation team didn't need to enter the process vessel for cleaning. FIGURE 2 A vacuum conveyor mounted on a column lift device features an electric lift mechanism controlled via a remote device to easily raise and lower the vacuum receiver above process equipment.