Case Study

Automated Storage/Retrieval System has Telescopic Forks for Better Material Access

Source: Westfalia Technologies, Inc.
Westfalia Technologies, Inc.ich Inc., a producer of flavors and fragrances, required an Automated Storage and Retrieval System (AS/RS) at its Princeton, N.J., plant. To support production operations, the system needed to present the raw materials when required by the selected recipe, then re-store the unused portions while maintaining accurate inventory control. Westfalia Technologies, Inc.ich needed to build an automated warehouse for 3,300 pallet positions, for 3,000 stock-keeping units (SKUs) of low-lot sizes in a 200x80-ft. building. Due to current AS/RS equipment constraints and the site dimensions, Firmenich was faced with a five-aisle, five Storage Retrieval Machine (SRM) system, or three SRMs with a transfer car. Both alternatives were expensive since throughput requirements were only 100 pallets/h.

Telescope access
Westfalia Technologies designed an innovative new storage configuration utilizing a Storage Retrieval Machine (SRM) with a Westfalia Telescopic Satellite (TSAT). This new concept in single-deep systems allows one SRM to access all pallets in the warehouse. This reduces the need for additional costly SRMs, and allows the optimization of throughput and storage capacity that until now was only possible in high-density storage systems.

As in a classic single deep system, Westfalia's SRM runs on a floor rail and is captive to a single aisle. The pallets, however, are not stored immediately off the main aisle, but in corridors that branch off of the main aisle. These corridors are accessed by a TSAT equipped with telescopic forks, which is transported by the SRM.

The SRM carries the TSAT on a hoist carriage and automatically positions it at the correct corridor and level. The TSAT then drives off the SRM and into the rack corridor. Riding in special channels shaped like the Greek letter sigma (S), it travels down the corridor and stops in front of the proper rack position. Here the telescoping forks extend/retract to either pick up or store a pallet.

Based on Firmenich's throughput needs (44 pallets/h inbound, 56 pallets/h outbound), the final system was designed with two SRMs, as shown in Figure 1.0, Firmenich Design. This design provides a near-perfect balance of storage and throughput, and minimizes costs. Note that the center rack can be accessed by both SRMs, which provides redundancy in the event of crane downtime.

How it works
Raw materials arrive at the unloading dock in the form of 55-gallon drums. The lots are barcoded and palletized. Each pallet is then assigned a permanent barcode. This allows multiple SKU's to be stored on the same pallet to maximize space utilization.

Two views of the Westfalia TSAT

System management, including inventory control, is provided by the Westfalia Warehouse Control Computer (WCC). Pallets are identified by the WCC, using an omnidirectional barcode scanner, as they enter the system on the conveyor input spur. This alerts the WCC that the pallet is in the AS/RS awaiting storage. All pallets are profile-checked, then move to the pick-up and delivery stations. The WCC assigns each pallet a storage location based on pre-programmed storage and throughput optimizing algorithms. Once in position, the SRM picks up the pallet and stores it in the proper location.

When manufacturing personnel require product to be presented to them, they simply identify a specific recipe that contains the amounts and types of product required. The WCC interprets the recipe into a list of retrieval missions and begins to deliver the proper pallets in the order specified by the recipe.

Manufacturing personnel often utilize only a small amount of product within a drum. This product must be returned to the AS/RS with the quantity per SKU file updated to reflect the new amounts on the pallet. A user-friendly menu system allows the operator to update the quantity fields for each SKU. The pallet is then brought back to the induction station, where the pallet number is re-identified with the updated drum quantities and re-stored in the AS/RS.

This innovative approach to single deep storage systems enables close matching of throughput and storage demands while substantially reducing costs and equipment requirements. Westfalia's Satellite AS/RSs, available in Multiple Deep and Single Deep configurations are custom-designed for each application.

Westfalia Technologies has been supplying material handling systems for over 20 years, with over 120 installations worldwide, in applications ranging from food processing to pharmaceutical to specialty chemicals.

Contact the company at: <%=company%>., 20 Conway Street, York, PA 17402. Tel: 1-800-673-2522 or 717-764-1115.

By Nick Basta