Across the globe, changing conveying requirements are stimulating the development of new materials handling solutions. Peter Guttridge, chairman of Guttridge Ltd, a leading supplier of bulk materials handling equipment, takes a look at market trends and the benefits delivered by optimised equipment design.
The efficient handling of bulk solids underpins the effectiveness of processing operations across a very wide range of industries. By installing materials handling solutions that are exactly tailored to the application, users can enjoy year on year reliability with minimal manual attention. Achieving this goal, however, relies upon choosing the best technology for the job, and on designing and engineering equipment that fully meets the required duty, even as those duties continue to evolve.
Trends in conveying
In today’s market for conveying solutions some very clear trends are driving development. With commodities such as grain, minerals and aggregates, for example, the economies of scale dictate larger scale facilities and an associated demand for increased throughput, and there is an intense focus on high reliability. Longer running cycles, minimal maintenance and energy efficiency are all primary issues. Higher capacity machines require the use of stronger belts and chains and it is also increasingly common to specify automated monitoring systems. These might include rotation sensors, belt alignment sensors and bearing temperature sensors, all of which support early fault detection and allow more efficient maintenance regimes.
In contrast, however, the rapid emergence of new economies means that in some parts of the world there are new users of conveying equipment who are handling global commodities with little local experience to draw upon. Here, the emphasis may be on identifying simple solutions that meet the strict limits on capital expenditure, in what can be fledgling companies with limited access to capital.
In some of the newer industries there is still much to learn about how best to handle the materials used, no matter where in the world the operation is taking place. Those transporting biomass, for example, face the considerable challenge of managing feed material that is subject to significant variability. The density, dust and moisture levels of biomass can all change substantially, and its characteristics can also be altered by the action of mould spores, so there is a need for truly robust solutions.
The food, pharmaceutical and chemicals industries are established users of conveying equipment. Here the continual development of new formulations brings with it fresh handling challenges. Customers in these sectors are looking for equipment that works reliably from the outset, even with a brand new product, and in the case of pharmaceuticals and food fulfils the most demanding of hygiene regulations.
Finally, there is the overarching issue of modern safety policies and practice. Today’s equipment must conform to the guidance laid out in a raft of regulations that includes: ATEX; CE marking; COSHH; and, here in the UK, the Health & Safety at Work Regulations. In combination these result in a complex set of rules and recommendations to interpret and apply in an appropriate way.
Responding to industrial need
With five decades of successful materials handling experience, Guttridge faces these ongoing challenges with enthusiasm, considerable applications expertise and an ongoing strategy of continuous improvement that focuses on safety, ‘on time in full’ delivery, and quality.
Listening is the first step in any project because an exact understanding of customer requirements is central to the overall approach. Design is handled with the latest 3D software, with each system tailored specifically to meet the application, and Guttridge has recently invested in a modern powder tester which is now widely applied for any products that are new or have uncertain flow characteristics.
The powder tester quantifies the flow characteristics of a material bringing a scientific approach to the development of solutions for tough powder handling applications. By reliably differentiating the flow properties of different materials, and even different grades of the same material, it supports confident equipment design, delivering right first time handling solutions, even for tricky to handle powders.
All construction, across the complete range of stainless steel and mild steel equipment, is handled in-house, the skill and motivation of the workshop providing the flexibility to efficiently deliver bespoke solutions wherever required.
Together these capabilities make for strong and reliable partnerships in materials handling projects as the following case studies demonstrate.
Prince Minerals – developing a reliable solution for abrasive materials
At its site in Stoke-on-Trent , Prince Minerals Limited, a leading international processor of speciality industrial minerals, mills silica sands to produce powders. Milled silica is transported by bucket elevator from the ball mill up through the building so that it can fall under gravity through a desk sieve, and then onto an air classifier.
Cost -effective in terms of initial capital outlay and energy efficiency, bucket elevators are a sound choice for this application but Prince Minerals had encountered a number of reliability-related issues with an earlier system. In a recent upgrading project the brief to Guttridge and SGH Equipment, the project engineers responsible for installation, was to engineer a solution that would significantly enhance reliability.
The highly abrasive nature of milled silica makes this a relatively demanding application. To tackle it, Guttridge designed and manufactured a system with a number of special features calculated to deliver the low maintenance, high reliability solution required. These included:
- Steel buckets with wear resistant metal bands to extend working life
- Hardox wear plates on the inlet and outlet of the conveyor to minimise wear in these high throughput areas.
- A cage and cone boot pulley system to prevent material getting in between the pulley and the belt and causing damage
- Stand off bearings with integral air purge to prevent the ingress of dust into the bearings and enhance reliability.
- Larger casings to reduce the risk of material build up and the likelihood of damage to the buckets in the event of any belt tracking problems.
This solution runs smoothly with minimal attention and has eliminated the reliability issues encountered with previously installed systems. Features such as these may, in some instances, add extra cost, but over the long run deliver the reliability that operators increasingly require. Understanding not simply what options are available, but exactly when they are needed, delivers significant value to the customer.
Case study: Cannington Enterprises – tackling new conveying applications
Cannington Enterprises is a family-owned business with its origins in agriculture. Successful diversification into the cold storage business, several decades ago, led the company to more recently consider further expansion into the ‘green energy’ market. As a result it now operates three anaerobic digesters. These convert waste from a number of sources, including food waste from the cold storage business, into biogas. Today the amount of fuel produced far exceeds that required for the on-site cold storage facility and in fact generates up to 1.5 MW of electricity, enough to power 3000 houses, which is fed back into the national grid.
Guttridge has provided Cannington Enterprises with a number of conveying systems that robustly and reliably transport their mixed waste streams, which include food complete with packaging materials. Blowers were initially considered for material transport but the feed is simply so variable that this approach is impractical. In contrast, mechanical conveying comprising enclosed, troughed screw conveyors, has proven highly reliable, and in combination with the hoppers and screw dischargers also supplied, provides a reliable integrated solution. Indeed these systems have been so successful that the company has ordered similar equipment for a second processing line.
Building for the future
Engineering conveying solutions that deliver, whether for a completely new material or for better performance, relies on applying experience, understanding and commercial know-how. Companies with the right blend of skills innovate systems that over the long term ensure reliable, trouble-free operation, and therefore bring considerable value to those investing in material handling equipment.