Volumetric screw feeders
Volumetric screw feeders control the flow by measuring a constant volume amount over time by changing the speed of the feeding tool. In the case of screw feeders, this is the rotational speed of the spiral screw with a full screw, with center rod, while in the case of a belt weighfeeders – the belt speed.
Gravimetric screw feeders
Gravimetric feeding (loss-in-weight type) is carried out by devices that receive material in advance from the hopper or via another transporting device and accurately feed the material into the process with a certain efficiency. The feeding tool in this case is a screw with center rode or a spiral, a vibrating conical funnel or a belt. The name loss-in-weight means weight loss and strictly defines the principle of work – the measurement refers to the loss of material from the feeder along with its dosing. Thanks to fast control systems and accurate load cells, the device delivers the exact amount of material, both as a batch mode (kilograms) and in a continuous mode (kilograms per unit of time).
Properties of bulk materials
The characteristics and behavior of bulk materials differ with their physicochemical properties and the looseness measure. The critical parameters are bulk density, size, and type of grain, susceptibility to clumping, hanging, adhesion, and hygroscopicity. There is no universal way to dispense any material. Thanks to the use of various solutions and options, however, we can accurately dose even theoretically hard elements in administration.
Types of feeders
The easiest to feed are materials with high flowability. The selection of a suitable volumetric or gravimetric screw feeder’s feeding tool and drive parameters provide an efficient way to feed them. We use screws with a special design for easily aerated materials with properties similar to liquids. Materials with a tendency to clumping and sticking inside the tank require a separate agitator, which ensures high filling of the screw. Such an agitator can be built-in horizontally or vertically. Fragile and easily damaged materials must be handled gently. For them, the most reliable choice seems to be a vibrating feeder. For working in difficult conditions (e.g. cement, chemical, limestone industry) the DTC belt weigh feeder is perfect.
Constinous and batch feeding
Depending on whether your process requires a constant flow or a fixed portion of material, we have a solution for you. We offer screw, belt and vibratory dispensers that can be operated continuously or portioned.
We equip all of our loss-in-weight feeders with Flex programmable controllers. If you already have a feeder and would like to upgrade it, we can implement it in your system. Flex is a modern control system equipped with a color touch screen and extensive communication options. The great advantage is the ability to modify the program and visualization, so you get a custom made product.