Simple Solutions That Work! Issue 17

31 BACK TO BASICS KEN STRAUSBAUGH Technical & Testing Manager Klein Palmer Inc. ARTICLE TAKEAWAYS: • Maintaining surge hopper capacity to reduce downtime • Methods to move sand to the silo • Don’t forget the storage level sensors! S and storage is a critical factor in design of an efficient No-Bake foundry. Capacity, location, design, level sensor placement, and safety protection must all be considered before finalizing a storage. STORAGE CAPACITY The first step in designing a storage system for sand in a No- Bake foundry is determining the storage capacity required at each step through the process. The bulk new sand storage volume requires sufficient capacity to hold the contents of a delivery truck or the contents of a rail car before demurrage charges begin plus the capacity to continue supplying the foundry when the level falls to this level until the next container arrives. The bulk reclaimed sand storage volume should be sufficient to contain one shift’s usage plus the quantity of sand in un-poured and poured molds on the floor. This capacity allows molding and core making to continue for one shift even if no sand is returned to the system because of any equipment breakdowns. This capacity also permits the occasional clean-up Sand Storage Equipment Basics for No-Bake Foundries without discarding or double handling of sand. The bulk storage for new and or reclaimed sand at mixer molding and core making stations should be large enough to continue production during the anticipated downtime required to get delivery equipment running again. A good preventative maintenance program plan and execution minimizes downtime, but it can still occur, and time will be required to get the appropriate personnel on site, troubleshoot, and correct the issue. Localized sand storage capacity at each mixing station is recommended to contain 2-4 hours of new and/or reclaimed sand whether that is mixed or individual storage of each sand. The capacity of intermediate surge hoppers in the process should be large enough to continue to receive sand or discharge sand to the next step after an interruption of the process ahead of or after the surge hopper. This quantity is based on the amount of time required to gather maintenance personnel, troubleshoot, and repair or replace components of the delivery system. Generally, it should be assumed that surge hoppers will be ½ full so that half of the capacity is available to receive, and half of the capacity is available as supply. Continued on next page