Press Release

SiloTray: Keeping the flow

The Brabender SiloTray reliably and completely discharges poor-flowing ingredients at high rates from silos and bins. This is accomplished by linear vibration and a customized baffle design. The SiloTray is ideally suited for granules, pellets, flakes, fibers and chips as its vibration technology does not use internal agitation therefore allowing gentle discharge. The SiloTray also prevents uncontrolled flow with its unique vibration technique. In addition, it uniformly distributes the material weight in the bin.

Problem 1: bulk material bridge

A bulk material bridge forms when the bulk material gets wedged in the discharge hopper, meaning it can no longer flow on its own and an ingredient bridge is formed.

Factors influencing the formation of bridges in the silo:

  • internal friction
  • grain size and shape
  • its moisture content
  • kinetic friction between the ingredient and the hopper wall, and the bin shape

Problem 2: rathole

If a rathole forms, the adhesive forces of the bulk material on the bin wall are too high. This results in an ingredient build-up from the wall to the middle of the bin, meaning that only the column of ingredient located above the outlet flows. This rathole significantly reduces the silo’s useable capacity.

Factors that influence the formation of the rathole:

  • the properties of the bulk material and
  • the smoothness of the bin’s inner wall

How the SiloTray discharge aid works?

The SiloTray can prevent ratholing and bridging. Two electromechanical unbalanced motors mounted to the cone exterior, work together with a suspended subassembly to create a linear motion. These linear vibrations improve the flow of the bulk material and ensuring ‘first in – first out’ discharge. This non-compacted discharge can be fed into downstream volumetric and gravimetric screw feeders or conveyor systems.

How is SiloTray set up?

The SiloTray is attached to the discharge of a silo/bin and is comprised of: An outlet cone with a mounting flange ring and integrated linear baffles. Two force adjustable electromechanical vibration motors are mounted on the cone exterior. The cone assembly is isolated and suspended from a bin mating flange by flexible hanger rods and connected with a dust tight flexible sleeve. The bin mating flange is supplied loose and field welded to the customer bin or silo by others. This assembly forms a robust structure ensuring uniform distribution of the dynamic vibration forces. By adjusting the vibration force and speed, the ingredient flow rate can be regulated. When flowing, the ingredient moves between the linear baffles into the cone and is guided to the SiloTray outlet.

Can I use SiloTray in combination with a feeder?

The SiloTray can be used in conjunction with a feeder in applications where precise ingredient flow is required. In this combination, the SiloTray pre-feeds the feeder below with conditioned ingredient. The SiloTray flow rate can be regulated by adjusting the vibration and force levels. The feeder and SiloTray are matched to optimize system performance. These devices are simultaneously started and stopped. A flexible connection is used between the two devices to prevent vibration transmission to the feeder. If required, a shut-off valve can be used to prevent unwanted ingredient flow.

Which options and accessories are there?

There are many options available for the SiloTray.

Load cells and controls
can be mounted on the bin which allows level measurement of ingredient. This measurement is important when the SiloTray is used to refill a loss-in-weight feeder.

Four different sizes (ranging from 600 to 1500 millimeters in diameter)
This enables us to provide the customer with the correct device for practically all bins and silos.

Individual designs for the product temperature
While our standard versions offer a product temperature range of 0 to 45 degrees Celsius, both higher and lower temperature versions are optionally available.

Explosion-proof options
comply with Regulation 2014/34/EU (ATEX)

Gate or butterfly valve
to control the loss-in-weight refilling process

Various process connections including double wall outlets
at the discharge

Special solutions
like flexible connections made of silicone or neoprene or special motor voltages and frequencies

“The SiloTray is ideal for controlled discharge of bulk materials in a non-compacted condition, with or without volumetric feeding, and at a defined and predetermined rate into the downstream process.” Michael Katzbach, expert für discharge aids at Brabender Technologie

Do you have further questions about the SiloTray and your specific application?
Contact our expert here.

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