Another project done – the gravimetric screw feeder in the hygienic version!
We provide devices for various types of industry. One of them is the food industry, which is very demanding in making machines. The feeders we produce are made in one of two variants: standard or hygienic. We just finished the production of one of them!
The standard design of the feeder is made of carbon steel, powder coated with polyester paint. The hygienic version is made of stainless steel. In this case, the customer wanted it to be made of 1.4301 (AISI304) steel, but on request, we can also make it of stainless steel with a higher chromium content – 1.4404 (AISI316L).
The inside of the feeder (components in contact with the material) are always made of stainless steel. In the case of very corrosive materials (e.g. salt), AISI316L steel should be used instead of AISI304 steel.
The total surface of our feeders is electropolished as standard. The welds inside the device are carried out continuously, which prevents the remaining material from remaining in the gaps – it is unacceptable in the food industry. In the hygienic version, the continuous welds are also led outside the device, and the welds inside the feeder are additionally ground and electrochemically etched. In addition, in the hygienic version, the inner surface of the device is ground to a roughness of Ra<0,8 µm.
The SEW motors used by us, which drive the feeding tool and the agitator, have the IP65 ingress protection standard, but at the customer’s request, we can also supply the motors in an aseptic version (IP66 protection, paint surface suitable for washing with detergents, no fan and cooling ribs). The customer has designated Ex-zone 21 (sporadic, the hazard may appear under normal conditions) – both inside and outside the feeder. Therefore, we used an ATEX version motor, adapted to work in an Ex-zone. Load cells made of stainless steel are also ATEX version and have a degree of protection IP68/IP69K, thanks to which they are perfect even in a demanding working environment and ensure a long service life. The junction box is also made of stainless steel. The control cabinet, on the other hand, had to be built outside the Ex-zone.
In the food industry, keeping the process clean is the highest priority. Our devices are designed with easy access to the interior in mind. The front panel of the feeder is adapted for quick disassembly and does not require the use of any additional tools. The feeding tool and the agitator can then be removed and the device is ready for washing.