How to Cope with Lactose Powder

Expansion projects are a chance but also titanic work: For a German producer of derivatives from milk and whey Derichs cope with high requirements in terms of dust-free system, high hygiene, Atex, batch tracking and gentle powder processing.

For almost 40 years, the company Milei has been concentrating on the enrichment and fractionation of valuable whey and milk ingredients. In order to expand the production capacity and to modernise the production process, it was decided to plan a new production. So a new 15,600 m2 state-of-the-art production facility was built, which allows milk processing to be increased from 20 million kg per year to 150 to 200 million kg of milk per year. The result is a production process in which high-quality products are manufactured with the best possible energy efficiency. After a long and intensive planning phase, under the direction of the engineering firm KSI as general planner for the whole new production facility, Milei decided in 2014 to have the entire bulk material plants, from the outlets of the four drying plants to the filling plants and an additional mixing line planned and realised by the company Derichs.

From the conception to the construction, the in-house production of many components to PLC programming and visualisation, Derichs was able to contribute its full experience in the field of plant construction in the food industry — especially in the dairy industry. The entire plant was conceived as two separate and independent parts:

• a plant for permeate and lactose powder; and

• a plant for high protein derivatives from milk and whey.

Conveyor Systems, Silo and Mixing Line

Both systems have several product- specific pneumatic conveying systems and a large number of silos. The conveying systems were specially designed for the properties and requirements of the finished products. As a result, the protein derivatives are conveyed as gently as possible by means of “dense phase” conveying systems with transmitting vessels. The lactose and permeate powders are promoted by specially developed systems in such a way that a reliable conveying is ensured without the usual glazing in the pipelines. For all systems, complex filters and air conditioning stations have been used to ensure the required product quality.

A total of 13 silos with a storage capacity of 150 m3 — each with Atex-compliant equipment — were installed. Furthermore, all silos are inside the building and are equipped with exact weighing systems that measure the silo content with an accuracy of up to 50 kg. This allows for a very accurate record of the inventories and tower services. Special delivery systems optimised for lactose and permeate powder ensure a safe product output even for longer product storage. Additional ventilation systems for the silo headroom, using filtered and dried air, ensure hygienic storage of the products.

To prepare various functional dry mixes, a mixing line was installed with a Derichs batch mixer type MBZ. Due to its large motorised cleaning doors, the mixer can be cleaned optimally and quickly. The two-shaft paddle mixer makes it possible to produce homogeneous mixtures quickly and in a product- friendly manner. The product feed and dosing is made from silos, big bags and sacks.

The end products are loaded into silo vehicles via a hygienic, pneumatic loose loading system. The silo vehicle is, during loading, in a closed and air-conditioned room.

Product Safety and Dust-Free System

All products are compliant with the highest requirements on foreign bodies before they are packed in bags, big bags or silo vehicles. For this reason, sieves, metal detectors and rotating permanent magnets are installed.

The dust-freeness of a system depends to a large extent on the quality of the system concept and the components used. Derichs’ experience with similar systems has been a key factor in achieving this goal. For example, all silos are kept at a slight vacuum to limit the dust load to an absolute minimum. In addition, the exhaust air from the filters is not led into the building, but to the outside. This, in conjunction with the experienced and conscientious operating team of Milei, ensures that the company always meets the requirements of its customers.

Autor: Marc Derix und Martin Röger, (beide Derichs)