Volumetric and Gravimetric feeders

Volumetric feeders

Gravimetric feeders

DATA SHEET

We produce feeders and micro feeders (single-screw and twin-screw) for precision dosing of powders and granules

Gravimetric feeders (screw and spiral feeders) for batch and continuous dosing.

Dosage is achieved with accuracy by volume or weight.

In case of continuous volumetric feeding, there is no immediate monitoring of capacity, but this is based on the initial parameter settings, assuming that the hourly capacity is constant. The error inherent to a system of this kind is on the order of +/- 5%.

In case of continuous gravimetric feeding, there is constant monitoring of the hourly capacity set in the control software and using closed circuit PID regulation to adjust the speed of the doser depending on the output reported by the weighing system. The error inherent to a system of this kind is less than +/- 2% and also depends on the correct choice of the doser depending on the product to be measured.

In the weighing function, load cells are used to add or subtract weight depending on the function required and whether batch or continuous type.

The accuracy, in this case, also depends on the type of load cells used and the incidence of the tare on the individual weight desired.

The RPM and the flow rate can be adjusted by means of:

  • Three-phase induction motors driven by vector inverters and additional servo-ventilation,minimum flow rate equal to 1/10 of maximum flow rate.
  • Brushless motors with dedicated drives, for an even wider dosing range, with a minimum flow rate equal to 1/20 of the maximum flow rate.

The capacities and dosages obtainable with both volumetric and gravimetric feeders vary from a few grams per minute to hundreds of kilos per hour depending on the models chosen during the design stage, based on the customer’s requirements.

The feeder programmers used can manage several components and formulas, depending on the configuration. In case of multiple dosages or components, dedicated PLC software can be developed with recipe setting via HMI user friendly touch panels for integration in industry 4.0 system.

Upon request the screw feeders can be designed and built in conformity to ATEX 2014/34/EU Directive Zone 2 – 22 / Zone 1 – 21

GALLERY

Gravimetric spiral feeder with 50 lt storage hopper and flat bottomed extractor with agitator functions for particularly viscous food powders. Gravimetric batch dosage for fine salt in a dissolving solution for brine.

250 diam. microfeeder for fine powders in easy-cleaning version, designed for both volumetric and gravimetric dosing. Feeding screw driven by brushless motor to permit extremely precise and accurate control even at low hourly capacities.

Continuous gravimetric micro-feeder complete with 75 lt storage hopper and 250 mm diam. flat bottomed extractor. Optional version designed for nitrogen overpressure (0.2 bar) to render the contents inert in case of installation in Atex GAS zones or to prevent oxidation of the powders that require maintenance of the aroma, such as ground coffee.
Continuous dosage software with retroactive control of hourly capacity and possibility of totalizing the quantity dosed in a set time period.

Gravimetric spiral feeder for discontinuous batch dosing. Fully openable for cleaning, mirror polished interior. Dosage of salt to the inside of the horizontal ribbon mixer for grains.

Gravimetric powder dosing system for net weight, complete with dedicated weighing software realized with Siemens S7 PLC.
Accurate dosage of individual weighings: +/- 1 gr.

Powder dosage inside a vertical ribbon mixer with 200 lt capacity, on loading cells via rotocell and gravimetric screw microdoser.

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