The application of transfer chutes is central to any operation in the bulk handling industry. The mining sector, in particular, presents a number of challenges due to the nature and volume of the material being transferred from one point to another.  Regardless of the direction or type of transfer, there are some design requirements that require specific attention. These include reducing dust, the elimination of blockages, reducing wear on chute liners and providing the correct discharge velocity, as well as minimising material degradation and conveyor belt wear.

Mark Baller of Weba Chute Systems maintains that there is a need to challenge conventional thinking around chute systems and transfer points. “The current trend seems to be that the company is called in to supply appropriate solutions to recently installed chute systems that are not fully operational. This is a huge concern and needs to be addressed as a top priority.” He asserts that many of the problems associated with transfer points can be eliminated during the design stage. “We, therefore, urge engineers to consult with Weba Chute Systems during this vital phase. The experience and expertise we have gained, during thousands of installations, is available to assist engineers both in the design of new transfer points and the redesign of existing systems that are becoming too expensive to operate.”

One of the most common problems associated with conventional chute design is where the product drops, from any height, directly onto the belt. This basic design fault causes the most catastrophic damage and cost, as the impact of product falling directly onto the belt causes excessive wear and, in the worst case scenario, can even result in tearing of the belt. In addition to the impact experienced, excessive spillage also occurs resulting in an increase in maintenance requirements. This has a direct bearing on both productivity and costs, due to unnecessary downtime and component replacement.

Baller says that the common practice of installing skirting and a skirting box as a remedy to control spillage incurs an additional capital outlay and is not guaranteed to alleviate the problems associated with incorrect belt loading. “In some instances, other apparatus has been used on conveyor systems to avoid spillage caused by badly designed transfer points. However, these Heath Robinson arrangements often cause tremendous damage to the belt because of the manner in which the skirting is fitted,” Baller points out. Excessive spillage also causes material build up on idlers and can then cause major problems on a conveyor system if left unattended. In addition, a chute that has been engineered to allow a direct drop poses a safety issue when liners need to be replaced. The maintenance crew will need ladders and harnesses to access the inside of the chute, which is not considered best practice in the stringently regulated mining sector.

Another factor that requires close attention is the manner in which chute liners are installed. “Typically, chute liners are bolted or welded in place and the direct impact of material against these liners causes excessive wear. Additionally, liners can detach from the inner wall of the chute and fall through the chute, causing excessive belt damage, blockages further down the line and could even cause damage to the crusher,” Baller continues. “Conveyor belting is one of the most costly items in any bulk materials handling operation. Any operation achieving a lifecycle of less than three years life on conveyor belting needs to seriously review its transfer points, belt alignment, idler maintenance, pulley maintenance and cleaners. Weba Chute Systems’ experienced team of engineers is available to undertake a full analysis of existing and new chute installations and design a solution that is geared around cost effectiveness and operational efficiency,” Baller concludes.

DESIGNING FOR SUCCESS PIC 01 : Weba Chute Systems control material in a transfer point resulting in major advantages.

DESIGNING FOR SUCCESS PIC 02 : Control of material from the transfer point will optimise belt life.

DESIGNING FOR SUCCESS PIC 03 : Weba Chute Systems control material movement in such a way as to match the product discharge velocity with the belt speed completely eliminating or greatly reducing spillage.

DESIGNING FOR SUCCESS PIC 04 : Each Weba Chute System is custom design for a specific application.