Heavy-Duty Bucket Elevator Boot Section with Dust-Tight Internal Gravity Take-Up for Hydrated Lime

General Description

Pete Lien and Sons, Inc. produces hydrated lime at the LaPorte plant near Fort Collins, CO. Hydrated Lime is produced by hydrating quicklime. Quicklime is calcium oxide (CaO) and is produced by burning or calcining limestone (calcium carbonate) in a kiln at 2,000-degrees F. Hydrated lime can be used in water treatment, soil amendment processing, and many other environmental applications. As part of the bulk material handling process, bucket elevators are used to elevate hydrated lime to storage silos and to various areas of the process. Pete Lien and Sons had been having problems with several bucket elevators, in particular the boot sections were corroding and wearing out prematurely. Also, the spring-tension take-ups used to keep tension on the elevator chain were not functioning properly. KWS was contacted by Pete Lien and Sons to help resolve the problems and was able to supply a cost-effective and practically maintenance-free solution.

Design Parameters

KWS Advantages

Engineers from KWS made several site visits to Pete Lien and Sons and worked closely with the sales manager at Rocky Mountain Supply, a DXP Company, to determine the correct solution for the bucket elevator boot section in question. The KWS engineers took field measurements of the existing boot section and created a CAD model using Autodesk Inventor 3D. The CAD model was used for verification of the field measurements. The existing boot section utilized a spring-tension take-up with external bearings and seals. Pete Lien and Sons requested that KWS provide a superior take-up arrangement that would minimize maintenance and downtime. KWS offered an internal gravity take-up with a completely sealed boot section. The new boot section would eliminate any leakage of hydrated lime and reduce almost all maintenance. With many years of experience in the field, the KWS engineers were able to determine the exact weight required for the internal gravity take-up to keep proper tension on the chain while not exceeding the load rating of the chain.

Special Features

KWS designed and manufactured a heavy duty bucket elevator boot with an internal gravity take-up. Hydrated lime is a very fine bulk material and was leaking through the shaft seals of the existing bucket elevator causing maintenance and operational problems. The hydrated lime was contaminating the external bearings and take-up springs causing failure. KWS made the boot section completely dust-tight. As part of the internal gravity take-up, hard iron bearings were located inside the boot section to support the tail sprocket and shaft. The internal gravity take-up was weighted to provide tension on the elevator chain. The internal gravity take-up allowed Pete Lien and Sons to completely eliminate the need for the spring compression take-up. All unwanted leakage, bearing failures and downtime were eliminated. The internal components of the new boot section were constructed from heavy wear-resistant steel for longer life. Lifting lugs were added to the new boot section for easy installation along with bolted, dust tight, OSHA approved inspection doors for access to the inside of the boot section.