By Lee Mueller on Feb 21, 2020 2:20:19 PM
I recently had a discussion with a coworker on the aspect of confined space and how to reduce its dangers. Most of the time, confined space issues refer to entering silos, bins, hoppers, and chutes. Confined space entry requires a litany of policies, procedures, and documents to be reviewed and approved prior to entry into the confined space.
Load Zone & Confined Space Entry
The bulk materials handling industry has known for years that air cannons can greatly reduce the frequency of confined space entry due to material buildup in silos, bins, and hoppers. The outlier in this discussion is the loading chute. The load zone, in many applications, is the source of large amounts of escaping material called spillage. This is primarily due to the improper placement of the material dam or wear liner - placed either inside or outside of the chute wall.
Most conveyors are designed with troughed idler sets in the load zone impact area. This design permits the belt to deflect down and away from the sealing sides of the chute when the load lands on the belt. Because wear liners are usually placed up from the belt due to belt sag, the load pushes against the skirting, resulting in spillage.
How Does this Relate to Confined Space and Cleanup Costs?
Let's start with confined space...when you use internally-secured wear liners, you are unable to address normal product wear without a scheduled outage. The wear liner does a real good job for a short period of time, but as product wears away from the belt, the gap gets larger and larger. As it does, the skirting is not going to retain material in the chute.
This is where cleanup costs come into play...now you are dealing with a serious cleanup issue until the next outage when you can gain access to the confined space to correct the wear liner spacing. When you install wear liner on the outside of the chute wall, you eliminate the need for confined entry to deal with wear liner issues. This application is most effective at reducing spillage along the sides of the chute wall. It is also easily replaced with minimal downtime to help you maintain chute wall integrity in the load zone.
By using an external wear liner, you can reduce your cleanup cost and eliminate one aspect of confined space entry. Winner winner chicken dinner.🍗