Here it is in it’s entirety reposted:
Bucket conveyors are frequently used in many process settings for bulk material conveyance. As an equipment choice, bucket conveyors can give many years of reliable service provided they are application engineered and properly installed, operated, and maintained. This article presents five key tips that will allow users to obtain the maximum performance from their bucket conveyor and reduce the incidence of downtime and lost throughput.
A key aspect of bucket conveyor operation is to ensure the successful transfer of material from an upstream feeding process into the conveyor. To achieve this, particular attention should be paid to the height from which material is dropped into the conveyor. A low drop height means a gentler product transfer, maintaining product integrity, while reducing the amount of dusting and providing better overall infeed control. Higher discharge elevations can also cause certain products (i.e., those with rounded or spherical particles) to bounce and may cause containment issues at the conveyor infeed.
Product dusting can result in the deposition of material onto surrounding equipment and structures, necessitating cleanup. Dusting may also cause the build-up of material within fully enclosed bucket conveyors, which can result in accelerated equipment wear and tear. Finally, product dusting may create an explosive atmosphere, as well as constitute a health hazard.
To avoid the performance losses associated with feeding from an elevated drop height, a good rule of thumb to follow is to always feed material into the bucket conveyor from the lowest drop height possible. Ideally, material should be gently deposited into the conveyor, rather than being dropped in from an excessive height.
If upstream feeding processes are difficult to modify for achieving a lower drop height, a common solution is to raise the lower portion of the bucket conveyor. This can be easily accomplished by installing a bucket conveyor equipped with custom-sized legs to raise the infeed elevation. In addition, adjustable floor supports enables minor height variations and provides leveling for uneven floors.
When material is unevenly distributed within the conveyor’s buckets, product spillage and asymmetrical wear of the bucket surfaces can result. Often a design issue, this problem frequently arises when product is being fed in at right angles to the conveyor (for example by a vibratory feeder or belt conveyor). As product is fed into the conveyor, it tends to accumulate on the feed side of the buckets, causing wear and overfilling on that side.
The remedy to this problem lies in good equipment design. A well-designed conveyor will be equipped with a bias-cut infeed chute which ensures even distribution of product within the buckets, even when fed at right angles.
A common operating mistake is to run a bucket conveyor at a speed which either under-fills or over-fills the buckets. While operating speed is often a function of the type and bulk density of material being conveyed, for every material there is an ideal operating speed that results in an optimal bucket fill. Under-filling buckets by running the conveyor too fast can shorten conveyor life as the conveyor runs longer than necessary to move the amount of product required. While over-filling the buckets by running too slowly results in product spillage and loss. The trick is to find, and set, the operating speed that results in an optimal bucket fill for the type of material being conveyed.
Product spillage resulting from bucket over-filling imposes two penalties. First, there is the material and throughput loss, and the need for cleanup. Secondly, spillage of material into the infeed or discharge areas of the conveyor may result in equipment wear and tear as the bucket drive assembly moves through the accumulated material. If the accumulated material is sticky or abrasive in nature, accelerated wear and compromised performance of critical drive components may result.
Equipment suppliers will often quote conveyor capacities as function of operating speed and volume required, using a specified percentage to which the capacity of the individual buckets on the machine are filled. For example, TipTrakTM bucket conveyor capacities are quoted using a 67 percent bucket fill rate. Using these parameters, an engineering calculation can be made which shows the capacity rate of the equipment as the bucket speed and material weight changes. Care should be taken to select equipment which can be run at the speed needed to achieve the desired throughput for the material being conveyed, while achieving the bucket fill percentage recommended by the equipment manufacturer.
Like any type of operating equipment, bucket conveyors may experience unplanned downtime if basic preventive maintenance routines are not followed. Consider implementing the following to improve equipment performance by reducing the occurrence of unplanned downtime:
Bucket conveyor performance can often be markedly improved through open communication with your equipment supplier. Reputable and experienced vendors are always willing to offer advice and suggestions for improving equipment performance. Equipment suppliers who have extensive experience in conveying materials are a rich resource from which to draw advice and guidance for overcoming performance challenges.
A key challenge in bulk material conveying is to understand how various materials will interact with the equipment when they are conveyed. Experienced equipment suppliers have extensive knowledge of material characteristics and behaviour which they have built-up over years of performing material tests and solving customers’ conveying challenges. Choosing an experienced equipment supplier and maintaining open communication to resolve issues as they arise is a key element in attaining high levels of performance from your bucket conveyor.
James Bransfield is the Engineering Team Leader for UniTrak Corporation Limited, manufacturer of the TipTrakTM line of bucket conveyors. Bransfield is responsible for UniTrak’s product engineering function and has over 20 years’ experience in designing bucket conveyors, including UniTrak’s latest model, the Multiple Discharge Conveyor (TipTrakTM MDC). For more information, visit www.unitrak.com. James may be contacted at email@example.com.
The rubber beltchain actually embedded with stainless steel aircraft cable so it is still metal and extremely strong. It is pre-stretched prior to being molded with rubber so it doesn't require lubrication or tensioning after it is installed.
Thanks for pointing out what to look for in a bucket conveyor! I agree that energy efficiency and interlocking buckets are great features. I never thought, however, of a rubber instead of a metal chain. That's interesting that they don't need lubrication. Are they as strong as metal?