Case Study: Turnkey Automated Bulk Batching System Reduces Lead Times
A new bulk batching system has eliminated changeover delays and enabled a refractories manufacturer to increase capacity by more than 50%.
Alsey Refractories Co. has spent over a century pioneering and refining its processes and practices to offer high-quality refractories products. The company specializes in the manufacturing and private branding of super-, high- and medium-duty firebrick, along with an array of specialties. The Alsey, Ill., plant manufactures numerous types of wet and dry mixes packaged in a variety of containers ranging from 1-gal pails to super sacks. The company’s most recent capital investment is leading it into its next growth stage.
Seeking an Upgrade
Facing production capacity bottlenecks resulting from a decades-old batching system, the company was determined to improve its productivity. Alsey’s management team identified several companies that could provide the necessary bulk batching equipment to meet its current needs and began a thorough evaluation process.
After careful review, the Alsey team selected a turnkey automated batching system engineered and manufactured by Ingredient Masters of Cincinnati, Ohio. Ingredient Masters was highly regarded by its customer references, and its bulk batching system offered Alsey more value at a lower price than the other suppliers.
“After evaluating all available options, we deemed the Ingredient Masters system to be the best fit for Alsey Refractories Co.,” says Andy Stafford, Alsey’s director of operations. “In addition, the references we received from others in our industry were most favorable of Ingredient Masters.”
Designing a Solution
Alsey’s original batching system was designed for high-volume batching of a single product line and did not accommodate small run jobs or varied mixes. The original batching system consisted of a series of eight 20-ton capacity bins that discharged onto a belt conveyor. The conveyor transferred the material to a mixer. Each bin would be opened and closed one at a time to discharge the correct amount of raw material onto the belt conveyor.
Emptying bins and cleaning out between product changes proved to be slow, manual labor that caused significant delays in the production process. Manpower requirements for a change-over could easily tie up several workers for a full day. The open belt conveyor also contributed to dust concerns within the plant. As the industry continued to evolve, Alsey had to become more adaptable and responsive to customer demands.
Ingredient Masters evaluated the situation and designed a bulk batching system that is custom engineered specifically for Alsey Refractories. The system consists of two rows of 10 rotationally molded polyethylene dispensing hoppers, each with storage capacity of up to 54 cu ft. With 20 total hoppers, Alsey has the flexibility to batch any of its specialty mix formulas with the push of a button.
“We gave Ingredient Masters a target batch time of 10 min with an accuracy spec of ± 2 lbs per ingredient draw,” says Stafford. “Our formulas range from 2,300-4,000 lbs, and the system is always well within the specification. It is a very accurate system. In fact, the new system typically completes a batch in 5-8 min, depending on the number of ingredients in the formula, and accuracy is usually within ounces rather than the ± 2 lbs allowed.”
Ease of Use
Alsey’s new system is a gain-in-weight bulk batching system that uses a platform-scale cart traveling on a V-groove track system through the dispensing zone. A frame is built onto the scale cart to hold the bulk bag that receives the discharged formula mix.
The operator begins the batching process by selecting a formula on one of two human/machine interfaces (HMIs). One is located on the floor by the scale cart load/unload station and features a 19-in. Factory Talk View touchscreen with Rockwell RS Logix software. The second HMI is located on the operator platform at the hand-add station and features a Nematron 10-in. screen.
An Allen-Bradley Conpact Logix controller checks to ensure the ingredients needed in the selected formula are available in the dispensing bins. The controller provides an alert if there is an insufficient amount of any of the ingredients in the formula.
If the system indicates a “ready” condition on the main HMI screen, the operator starts the batching process. The computer-controlled scale cart equipped with bulk bag indexes to the far end of the system and stops under the appropriate dispenser. Proximity sensors located on the system support structure communicate cart position to the controller. A variable frequency drive allows the cart to efficiently move from position to position by changing speeds when appropriate.
Each dispenser is equipped with a slide gate valve to control the dispensing of ingredients from the bin. The air cylinders on each slide gate valve are equipped with a rod lock feature that allows the valves to be in any of four positions: full open, dribble, trickle flow or closed. An air fluidizer system in each dispenser ensures consistent product flow. A butterfly valve in the dust collection ductwork automatically opens during the dispensing of each ingredient, and a metal containment hood offers additional dust containment. After receiving and confirming the measured amount of ingredient from the first stop, the scale cart/bulk bag continues through the system, accepting ingredients from the appropriate dispensers for the programmed formula mix.
A mezzanine level hand-add station with a dispensing hopper on load cells is situated as the last dispenser before the cart exits the system. The hand-add HMI guides the operator through the process and uses load cell readings to confirm the amount of ingredient added. Once all hand-add ingredients are added to the hopper, a valve opens to discharge the hopper contents into the scale cart bulk bag.
The hand-add station is set up at an ergonomically ideal height for operator comfort, and a safety pallet gate offers additional operator protection when loading and unloading pallets of hand-add ingredients. Once all ingredients have been dispensed into the scale cart bulk bag, the cart returns to the home position for transport by fork truck to the mixer or another downstream processing stage.
“Our system is very user-friendly and easy to own,” says Scott Culshaw, president of Ingredient Masters. “There are no proprietary parts. We use only highly reliable, off-the-shelf hardware and software for easy maintenance.”
Dispensing bins are refilled using raw material packaged in super sack bulk bags. Raw material bulk bags are mounted into lifting frames that feature bottom fork truck access for easier handling in low headroom situations. The loaded frame is lifted by fork truck and positioned securely into channels in the support structure of the batching system.
One loaded bag lifting frame is positioned above each of the dispensing bins for dispenser refill. This allows the dispenser to be refilled while the system is batching, eliminating shutdowns while refilling the system. The bulk bag includes a bottom spout that releases raw material into the batching system dispenser for refill. Each dispenser features a manually activated damper valve that draws air from the top of the dispenser as it is being filled to control dust.
The Bottom Line
“We’ve increased our production capacity for the specialty mixes significantly with the Ingredient Masters system,” says Stafford. “After only two months of operation, we are able to show more flexibility for filling orders and have significantly reduced our lead times, both of which have shown a positive impact on our profitability. We’ve stayed in business for more than 108 years by making smart decisions like this.”