The hopper serves to feed bulk solids in powdered and granular form into closed materials handling systems, such as pneumatic conveying systems. Products can be fed from sacks, boxes, barrels or similar receptacles. As different branches will have very diverse requirements regarding quality and hygiene, the feeding hoppers are available in a variety of materials and surface finishes.
After opening the lid to the feeding hopper, the aspiration process of the interior starts, thus preventing dust from escaping while the product is poured in. Depending on the requirements, dust filtration can be implemented either via an attached individual filter with built-in filter cleaning or via a central filter station. To assist discharge of bulk materials with poor flow properties, the feeding hoppers have been fitted with rappers, vibrators, bin activators or aeration jets. The design can be adapted to downstream equipment such as rotary valves or dosing screws by using appropriate flanges for an optimum fit. Installation is carried out according to customer requirements using support brackets, consoles or in a separate frame.
An integral vibrating perforated sheet prevents packaging residue and other unwanted coarse material from entering production. The layout of the vibration motors and vibration elements and their direction of rotation cause the product to flow in a defined direction on the screen. Coarse particles that are larger than the screen mesh size are conveyed to the coarse material outlet and evacuated there. The inclination and intensity of the vibration motors can be varied to adapt them to accommodate each product. The circular screens are available with a polyester/plastic fabric in mesh sizes of 2 to 5 mm or with special metal screens in a range of mesh sizes with a maximum actual screening area and with no risk of wire rupture.
All operations at the new feeding hopper, such as filling, screen inspection, removal of coarse materials and screen replacement, are carried out from one side. It is quick and easy to replace screens using standard tools.
Throughput rate varies depending on the product and mesh size. The following throughput rates can be used for reference purposes: 4500 kg/h wheat flour with a mesh size of 3mm, 1,700kg/h powdered milk with a mesh size of 5mm.