Tag Archives: Weba Chute Systems

ENGINEERED TRANSFER CHUTES SAVE COSTS

The uncontrolled discharge of bulk materials through conventional chutes is associated with escalated maintenance and replacement costs. By custom designing and engineering transfer points, productivity is enhanced and costs are reduced. A number of blue chip customers around the globe have adopted Weba Chute Systems to increase efficiencies and decrease downtime.

Mark Baller, managing director of Weba Chute Systems, says that optimised plant design should consider each element within the process flow. “Globally, companies accept that best practice includes the incorporation of transfer chutes that have been designed and engineered to suit the specific application. Unfortunately, many project houses do not afford transfer chutes the same importance as a screen, grizzly, crusher or feeder.

“Another area that needs clarification is the erroneous belief that mines can reduce capital costs by installing a cheaply fabricated chute. Ironically, these poorly constructed chutes incur unnecessary operational costs for the customer. The global mining community acknowledges that poor design and implementation of transfer points can result in increased maintenance costs for minerals processing systems. This fact belies the belief that chutes are just fabricated platework,” adds Baller.

“If due consideration is given to customisation at the design phase the customer will benefit from reduced maintenance requirements, improved transfer conditions, longer conveyor belt life and higher throughput. In addition, the Weba Chute Systems are designed in such a way that they minimise impact that traditionally sends clouds of dust into the air. This boosts occupational health and safety compliance,” Baller continues.

The Weba Chute Systems team of engineers has extensive experience in the field and a wealth of intellectual property. “Each project is approached on an individual basis, with engineers adopting a hands-on approach. Liaison with customers during the design phase allows us to devise tailor made solutions that provide a high-level return on investment,” says Baller.

“Unfortunately, when a poorly designed or conventional transfer chute fails we are forced to go in after the fact and redesign and re-engineer, not only the chutework but often we also have to reconfigure the entire transfer point. If the systems were correctly designed and engineered from the outset, then these issues would not arise,” adds Baller.

The Weba Chute Systems team utilises Discrete Element Modeling (DEM) simulations as a verification tool only. “Design ideas and concepts should be derived from the intellectual property that exists in our engineering team. By complementing our own sound engineering tools and substantial practical knowledge with DEM, we are able to provide customers with a high-end transfer chute solution.

“We are not competing with the project houses. It is not a draughtsman’s job to design chutes. These products require custom engineering to ensure that the transfer point solution precisely meets the specific parameters within a given application. Customer satisfaction can be measured in improved material flow, minimal maintenance and a substantial saving on costs,” Baller concludes.

WEBA CHUTE SYSTEMS STILL BEST OPTION FOR LOWEST TOTAL COST OF OWNERSHIP

Tough economic times have unintended consequences, and one which is now starting to show is the installation of budget transfer systems. This is according to Mark Baller, managing director of Weba Chute Systems, who says that the company has been called upon by a number of operators to replace chute systems that have simply not made the grade in terms of performance or wear life.

“The bottom line is that plants have cut corners in terms of transfer points, and it is now starting to cost them significantly in unplanned downtime, reduced throughput and unnecessary maintenance,” Baller says.

Baller says that watching from the side lines, the company has seen many mines opting for the most inexpensive chute as a way of reducing capital costs, but that this strategy has not paid the expected dividends. “In fact, the opposite is true with these plants experiencing substantially higher total cost of ownership,” he says.

He puts forward the case for engineered custom transfer solutions and can point to numerous examples where chute systems that are tailored for specific applications have reduced all sorts of issues including blockages, high maintenance, spillage, noise and dust. The engineered Weba Chutes reduce operating costs with most chutes giving a full return on investment within 18 months.

“Although Weba Chute Systems may appear relatively simple and straightforward to produce, these bespoke solutions take a number of hours to engineer. We find that mines are now more open to comprehending that when it comes to chute systems it is not about the initial purchase price but more about the total cost of ownership,” Baller says.

Year of experience, hard won expertise and skill are the major differentiators that allow Weba Chute Systems to produce transfer point systems engineered specifically for a given application requirement. Transfer points are definitely not off-the-shelf products and Baller asserts that while anyone can do the basics when it come to the technical side of designing a transfer chute, it is not an exact science and there is simply no single solution for materials transfer.

Material being transferred through any plant is not constant, and material in the ore body is often not homogenous. This means that throughout the life span of a mine the properties change as different sectors of an open pit or underground operations are used.

Adding to the complexities is that often the material being handled will not be consistent with the test results used for the base design of the transfer point. Baller says that this is where years of practical experience play an important role in being able to engineer a design that will accommodate a range of material properties and operating conditions.

“There is a major difference between theory and practical use. This is particularly true of chute design where theory comprises only 30% while 70% depends on practical applied and site-specific knowledge, Baller says. “While it is essential for a successful transfer point design that correct and accurate information is received from the customer, there is also the need to tap in the skills provided by a specialist OEM such as ourselves to ensure the final product meets all the requisite parameters.”

Significantly, Weba Chute Systems has accumulated a depth of expertise over almost 4 500 successful installations. Weba Chute Systems are an engineered transfer point and not a quickly fabricated product.

WEBA CHUTES PROVIDE SOLUTION AT CARMEN DE ANDACOLLO IN CHILE

Weba Chute Systems has successfully engineered a new transfer point to replace an underperforming chute at Carmen de Andacollo in the Coquimbo region of Central Chile.

Carmen de Andacollo is an open pit copper operation; Teck owns a 90% interest in the mine with Empresa Nacional de Mineria holding the balance of shares.

The new chute system transfers material from a double deck screen feeding oversize material from both decks to a conveyor. Material throughput is 2 000 tph with a lump size of minus 85 mm.

Alwin Nienaber, technical director at Weba Chute Systems, explains that in the previous installation the manner in which material was being presented onto the conveyor was causing impact damage and excessive spillage. The spillage had to be controlled using extremely hard skirtings under such tension that this had been causing extreme damage to the conveyor resulting in frequent belt replacement.

“It is not uncommon for us to see this type of issue which arises from inadequate plant design,” Nienaber says. “When the transfer points do not receive the requisite attention during the design of the plant, numerous problems can occur during operation.”

As a transfer point specialist, Weba Chute Systems is a strong advocate of their involvement at the start of a project. “This approach ensures that the transfer points are engineered for the particular plant, with the advantage that material transfer will be optimised and wear and impact issues such as those found at Carmen de Andacollo could be mitigated from the beginning.”

Where operational plants experience issues with transfer points, Weba Chute Systems sends in its technical team to conduct a full design assessment.

According to Nienaber this is a critical step in the process as it will ensure that the solution provided takes all factors into account. He explains that the previous chute was essentially just a box structure and this was problematic as the material flow was not controlled and it directly impacted onto the conveyor from the screen. To add to this situation the receiving conveyor design was also compromised.

“We were able to design a new transfer point solution that would accommodate the shallow flow angle required in this application,” he says. “By custom engineering the chute we were also able to design it in such a way so as to feed the material onto the conveyor in the direction of belt travel. This then eliminated the issues associated with the previous direct impact.”

The design of Weba Chute Systems also allows for absolute control of the material and, in this application, has been configured to force a concentrated stream from the screen decks onto the conveyor. Due to the compromised general arrangement between the screen and conveyor, skirts are still required to eliminate spillage.

To provide further protection against sliding abrasion, the chute has been lined with high alumina ceramic tiles.

The Weba Chute Systems installation at Carmen de Andacollo was commissioned in the first quarter of 2017. Nienaber says that much of the work has been done through Weba South America which was established in Chile to service this region.

Under the leadership of Pedro Javier Vega, Weba South America has been making inroads into the mining and minerals processing sector. “The local team has a good understanding of the industry, its immediate and long terms needs, and will provide consistent support to this customer,” Nienaber says.

ADDRESSING THE TRUE COST OF SUB-STANDARD TRANSFER POINTS

The level of performance of a mine’s transfer points contributes to some of its highest maintenance costs, but many engineers often do not consider transfer systems as critical elements of the minerals processing systems.

This is the view of Mark Baller, managing director of transfer chute experts Weba Chute Systems; he believes that transfer points should be accorded the same importance as other minerals processing machinery. In particular, the effect of the chute’s performance on the life of conveyor belts – which can account for up to 60% of the capital cost of a bulk materials handling plant – deserves attention.

“The cost of replacing a conveyor belt – not to mention the downtime associated with belt maintenance and replacement – makes it worth looking more closely at any measures that will extend the conveyor’s life,” says Baller. “Typically, conveyors – like feeders, crushers, hoppers and screens – are selected to match certain operational requirements; however, there is little emphasis on the design of the chutes transferring materials between elements.”

This is a mistake, he argues, as chutes are essential elements in a bulk solids handling plant, and are also subject to operational characteristics and physical constraints.

“Among the most common problems on transfer chutes are spillage, blockages and high levels of wear on the receiving belt due to major differences between the material velocity and the belt velocity,” he says. “There is also misalignment of the receiving conveyor belt – which is caused by uneven loading from the transfer chute.”

Key to solving these challenges is good design, he emphasises. While conventional chute design often allows the uncontrolled discharge of bulk materials, Baller considers that a holistic design is necessary – focusing not only on the entry and exit points, but also controlling the flow, volume and velocity of the material being transferred.

“Each transfer point therefore needs to be custom designed, to control the direction, flow and velocity of the material,” he says. “Weba Chute Systems bases its designs on the ‘supertube’ effect which often employs a cascade lining system – allowing 95% of material to run on other material at all times. This may also be achieved using conventional lining systems.”

He emphasises that one of the designer’s aims must be to achieve controlled transfer of material onto the conveyor belt, reducing wear and tear on belts while also minimising the impact that creates dust. The results are cost saving for customers and better occupational health and safety compliance.

“The ‘super flow effect’ is designed into our products using sound engineering principles and sophisticated 3D software,” says Baller. “We also use Discrete Element Method (DEM) simulation as a verification tool.”

The company’s design philosophy has found its way into over 4,000 transfer chute installations in mines around Africa and abroad.

SCIENCE OF TRANSFER CHUTE DESIGN LOWERS END USER COSTS

Its scientific approach to the design and engineering of transfer chutes has made Germiston-based Weba Chute Systems a leader in its field, saving customers millions in plant efficiencies, longer equipment life and easier maintenance.

“We invest thousands of research hours into understanding the dynamics of bulk materials handling at transfer points,” says Weba Chute Systems managing director Mark Baller. “Employing sophisticated 3D computer software for our system designs, we follow this up with quality manufacture in our ISO 9001:2015 accredited facility. However, this capacity is only as valuable as the data that we get from our customers – so a close working relationship is a vital cornerstone for a successful outcome.”

Baller therefore emphasises that each project begins with a hands-on approach adopted by the engineering team, who together are able to leverage many years of field experience. During a site visit at the start of the process, the team identifies transfer issues and collaborates closely with the customer to develop a tailor-made solution.

“Cost factors are front-of-mind for all stakeholders in the mining sector, so we have to ensure a solution that will increase the return on investment within as short a period as possible,” he says.

It is also insufficient to view the design of transfer chutes in isolation from the broader working environment. Taking a systems approach to bulk solids handling design is essential to ensure operational characteristics are matched throughout the plant. This is a prerequisite to ensuring smooth materials flow through the entire plant.

“Optimising chute performance is a process of defining the geometry of the chute to reliably convey material from one point to another,” he says. “The complexity of chute performance means that chute design should be carried out at the plant design stage, and not added as a conveyance to transfer material from one point to another at a later stage.”

To ensure customer confidence and assurance that the product will meet its stated objectives, Weba Chute Systems provides process and performance guarantees, backed up by its substantial support network. These guarantees, set in accordance with operational and application parameters, are underpinned by quality manufacture, says Baller – a non-negotiable element of all products emanating from the company’s manufacturing facility.

“The results of our research, engineering and quality focus is reduced maintenance requirements in the final product as well as improved transfer conditions, longer conveyor belt life and higher throughput,” he says.

He adds that this philosophy drives the company to constantly improve its products – and to find ever more effective ways of helping clients manage their production costs. The implementation of well-engineered transfer chute systems becomes a key strategy in achieving clients’ budgetary goals

TRANSFER POINTS CAN CONTRIBUTE TO HIGH MAINTENANCE COSTS

Although transfer points potentially contribute to some of the highest maintenance costs on a mine, engineers seldom view transfer systems as a critical element of the minerals processing system.

So, says Mark Baller, managing director of Weba Chute Systems, who maintains that transfer points — by the very nature of their application — should be viewed with the same level of importance as any other machinery in the minerals processing cycle.

“The uncontrolled discharge of bulk materials through conventional chutes has a history of escalated maintenance and replacement costs, not least of which can be attributed to excessive wear and other related problems,” Baller says. “All of this adds up to unnecessary expenditure and a headache for the engineers concerned.

“Numerous successful installations of Weba Chute Systems have proved that the correct use of our streamlined, scientific approach to the dynamics of bulk materials handling greatly reduces the problems associated with conventional transfer chutes and results in significant cost savings.”

Each Weba Chute System is custom designed for a specific application, considering factors such as belt width, belt speed, material sizes and shape and throughput. Baller says there are numerous advantages to be gained from this locally developed transfer system which, when introduced on a new project, achieves the optimum design configuration for the application with the best belt cleaning arrangement and optimum selection of belt type and size. In addition, spillage can be virtually eliminated.

Further benefits that apply equally to retrofitted Weba Chute Systems and new projects alike include up to 80% reduction in material degradation, greatly reduced levels of dust and noise, reduced production losses owing to fewer blockages, significantly reduced spillage and vastly improved safety levels.

Easy access is provided for inspection and maintenance purposes and the system does not require ongoing supervision, again representing a saving in manpower and related costs.

Baller says Weba Chute Systems should not be compared to conventional chute systems but rather seen as an improved alternative or “upgrade”, because they adopt a completely different and unique approach to control and handling of bulk materials. For instance, the system uses a “supertube” with a cascade scenario, where 95% of the material runs on material at all times.

“When one looks at this process in slow motion, it becomes apparent that the bottom layer of particles in the product stream move in a tumbling motion and do not slide down the chute,” he explains. “This results in significantly reduced wear and in many cases the lip remains completely covered by material and rarely needs replacement.”

This manner of controlling material movement is taken a step further by designing the internal angle of the transfer chute in such a way as to match the product discharge velocity with the belt speed, which either virtually eliminates or greatly reduces spillage.

Extensive experience and technical expertise, coupled with applications knowledge, has positioned Weba Chute Systems as the leader in its field. The Weba Chute System design is accomplished using sophisticated 3D computer software. Data received from the customer is always verified, and in many instances Weba Chute Systems’ highly skilled personnel are in a position to make cost saving recommendations.

The quality of the manufacturing process is strictly controlled by the company’s procedures which are in line with its ISO 9001 certification. Performance guarantees, set in accordance with operational and application parameters, are provided with all Weba Chute Systems.

SPECIALISED PLANT NEEDS SPECIALISED CARE – WEBA

A trend on many mines to cut maintenance costs has sometimes led to general contractors being engaged to conduct repairs and servicing; this is generally not a good idea for specialised equipment, warns Mark Baller, managing director of Weba Chute Systems.

“Most customers are well aware that good maintenance is the right long term solution to preserve the value of their assets and ensure smooth operations,” says Baller. “Faced with financial pressure, however, outsourcing to general contractors is seen as a cheaper option, which it is actually not.”

The danger is that these service providers are not that knowledgeable about the specific products they are maintaining, he says. In many cases, for instance, they see the Weba Chute simply as platework, and conduct repairs in a fairly haphazard way through welding.

“What they don’t realise is that our chutes are custom engineered to meet the specific operational requirements of that mine, so the material chosen and the particular configurations of the transfer points cannot be changed willy-nilly by the incorrect installation of parts or components,” he says.

When maintenance is not conducted in line with the equipment design, this affects the performance of the chute, and ultimately has a knock-on effect on the whole materials handling process of which it is a critical part.

“This will often result in additional costs being incurred by the customer,” he says. “Operationally, there may be added impact and damage to the conveyor belts, or more spillage at the transfer point which requires added clean-up time. Also, dust emissions may increase, and these would have to be addressed.”

The eventual result of incorrect maintenance is that the unit becomes irreparable and has to be replaced. This introduces capital cost implications, on top of the operational and maintenance costs.

Retrofit replacement underway by Weba Chute Systems.

“So it is not difficult to see that it can be very dangerous to put the maintenance in the hands of a service provider that is not correctly trained or is not sufficiently knowledgeable,” says Baller. “By trying to save a little – say, R20,000 to R30,000 a month – on the maintenance cost, some mines put their whole operation in jeopardy. Even a single hour of lost production can cost the operation hundreds of thousands of rands in foregone revenue.”

The quality of maintenance, he says, has a direct impact on plant availability. In a recent case, Weba Chute Systems had collaborated on maintenance with a customer to keep their plant availability at between 96% and 98%. When a cost saving exercise led to a general contractor being engaged, the plant availability dropped to 89% – a significant drop that cost the mine substantially in terms of lost production.

“It wasn’t just our equipment that was affected,” says Baller. “All the OEMs were shifted off site in favour of the general contractor. Their drop in productivity was therefore not limited to just the chutes, but extended to a range of other specialised equipment. Without sufficient training on all the equipment, the contractor could not keep up the required standards, leading to this drastic reduction in plant performance and overall production.”

On the other hand, Baller says, there are a range of benefits that an OEM brings to a mining operation, that turn their maintenance charges into tangible value for the customer.

“In some cases, we have maintenance contracts which actually involve our own crews on site, who perform inspections and conduct the maintenance work,” he says. “The mine will order the spares when they are required, and we work hand-in-hand with the mine’s maintenance superintendents and engineers to schedule the maintenance on these plants.”

Lack of maintenance can lead to damage inside transfer points.

He says that Weba Chute Systems also have customers doing their own maintenance. “We assist them with random inspections, just to keep an eye on things, but they generally do their own planning and installation, as well as the ordering of spares,” says Baller.

CUSTOM ENGINEERED WEBA CHUTES SOLVE ALL ISSUES AT ISDEMIR STEEL PLANT

The first few transfer chutes leading into a plant handling material destined for furnaces and power generation applications commonly experience degradation, dust and impact challenges, whereas once the material is in the plant and needs to be bifurcated to multiple screens there is the additional challenge of material segregation.

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