Tecweigh, an Australian Made dynamic weighing specialist, have several food-grade solutions that Food & Beverage Industry News readers can implement to optimise their manufacturing processes.
With bespoke solutions used in bulk handling applications for dry materials, Tecweigh design and manufacture their in-motion weighing and metering products in Australia, sourcing most components locally.
With 25 years of manufacturing experience to provide quality weighing equipment to the Brisbane, Melbourne, Perth and Sydney areas, Tecweigh are based in Melbourne, Victoria. For the food industry in particular, their stainless steel volumetric auger feeder and weigh belt feeder set Tecweigh apart from their competitors.
The volumetric auger feeder features a simple design and has an internal agitation system that promotes product flow. Meanwhile, the weigh belt feeders – built for accuracy, dependability and food grade hygiene – offer great performance and easy calibration.
Volumetric Auger Feeder
Tecweigh’s business development manager, Barry Gamble, explains that the volumetric auger feeder is intended for precise dosing and flow control of dry powder or granular products.
Gamble says the augers are available in sizes from 12mm to 152mm in diameter, and there are various feeder sizes capable of dispensing between one and 20,000 litres per hour.
“It’s a screw auger, where its speed and diameter will determine how many litres per hour it can move, as opposed to kilograms per hour,” he said. “It’s all about how dense the product is. It’s suited for accurate dosing of powders and granular products into food; one major application is salt, spices, and seasonings in the snack food industry.”
The volumetric auger and Feedtube assembly is easy to remove, using a single lever operation. If an operator tries to remove the auger and Feedtube during operation, a safety sensor fitted to the mounting shuts down the drive motor.
Many feeders on the market have solid metal sides with the auger turning around at the bottom. This can lead to the product caking up and becoming stuck, which is known as bridging.
“In response to this, we have a flexible polyurethane hopper with external massaging paddles that prevent the product from bridging or ratholing,” Gamble said. “The flowability of the product is key to consistent loading of the auger which ensures reliable and accurate rate control. The options are single drive, where one motor will drive the massaging paddles and auger directly at the selected speed. For difficult or low flowrate products, a dual drive option with two motors is available, in this case the auger and the massaging paddles are driven independently.
“Dual Drive is the preferred configuration for Gravimetric or Loss-in Weight applications. Tecweigh feeders can be equipped with load cells, so you can measure kilograms per hour instead of litres per hour. Then using this weight feedback, the auger speed is adjusted to maintain an accurate dispensing rate as confirmed by weight during the process. The paddle speed can be reduced by comparison with the auger rotation to keep the material flowing smoothly through the hopper with minimal ‘mechanical disturbance’ affecting the weight measurement.”
This means that the food producer can determine how much product is being dispensed and if the speed of the paddle or auger needs to be altered.
“When refilling the inlet hopper, the weight signal from the load cells is ignored by the PLC and the last remembered speeds of the auger and paddles are maintained during the refilling process,” Gamble said. “Level sensors are not needed for the refill cycle as the actual weight in the hopper is visible to the process in real time.”
Weigh Belt Feeder
While the volumetric auger feeder is used for small and precise dosing, the weigh belt feeder can be used for any product in larger quantities. Gamble explains how it works.
“For the weigh belt feeder, the product arrives on a non-weighing section of the belt then travels over the weighing section and then over a second non weighing section before leaving the belt,” he said.
“It’s about mixing the raw product, recipe mixing, or batching. It works on many products and ensures each product is given the correct ingredients in the right proportions.”
There are certain elements that can be custom made to cater to the clients’ needs, such as the belt width, belt speed and the height and cross section of the material bed.
“We custom engineer the product using the customer’s parameters of product bed depth, belt width, and belt speed to optimise and meet the flow required in either kilograms or tonnes per hour,” Gamble said. “It could have an Ethernet IP output to go into a PLC that can monitor the scale parameters in real time.”
The accuracy of the weigh belt feeder is +-0.5 per cent for a single idler weighing system, or +-0.25 per cent for a dual idler. Another factor Tecweigh has considered in their designs is how to contain the material on the belt for different applications.
“Another important factor is containment of material on the belt which can be by a wave edge belt, or if they want a larger bed depth, they can use stainless steel side rails,” Gamble said.
“We are talking to a customer who produce salads and because it is a much a lighter product than say potato, the product bed depth bed needs to be higher to achieve the same throughput. We use parameters around depth, belt width, and speed to achieve the optimum throughput.”
Maximum accessibility, minimal build-up
Another feature of the Tecweigh weigh belt feeder is it minimises the amount of material build-up. On its continuous loop belt in the production line, once divested of its material the belt travels underneath where a spring loaded belt scraper cleans it as it moves.
“The inlet and outlet chutes can be custom-made to fit the needs of the end user’s process,” Gamble said. “Sometimes a tank or hopper is installed above, the head of product sits there and as the belt moves along and drags the product out at the speed that’s required. After weighing the product is dispensed off the end of the belt through a flanged discharge chute.”
The weigh belt feeders also include built-in calibration weights.
“Firstly, you zero a clean belt–any small deviations in the weight of the belt are absorbed in the zero-tracking function of the WP20 Weight Processor,” he said. “A calibration cycle is initiated and the WP20 process guides you through adding the weights and advises you when to take them off. Then the calibration process is complete.”
Carrying more weight
Having been manufacturing in Australia for over 25 years, Tecweigh knows what works and what customers require in the food industry, among many others. While this has meant that the stainless steel volumetric auger feeder and weigh belt feeder have been sold successfully over the years, the dynamic weighing specialist is now working to deliver a new range of advanced products.
“Despite COVID-19, our many loyal customers together with welcome new ones helped Tecweigh to record growth last year,” Gamble said. “We are working to keep the momentum going into the future with a new generation of weighing control systems, due for release later this year. Watch this space!”