Case Studies

Case Study: Food Supplement Production

Increasing requirements in the food and supplements industries form challenges to raw material handling and bulk materials technology, even when handling harmless substances. Avoiding spills and cross-contaminations is necessary and requires closed transfers between processing steps. Attention must also be paid to the handling of different containers, such as Super Sacks/ Big Bags (FIBCs), drums, containers or sacks, in order to ensure transport with no or minimal dust and no degradation of the substance. Our client is a well-known Swiss manufacturer of dietary supplements in various varieties.

Process Description

Ingredients are supplied from FIBCs and regular sacks and include up to 15 different raw materials depending on the recipe. Just 2 operators are needed to supply the production with raw materials and handling packaging materials at the filling station. The process, including the HECHT equipment and the mixer, are fully automated. A separate recipe management system forms the interface to the existing merchandise management system. The system is capable of producing 2.25 tons of finished product per hour.

Cleaning is done by dry flushing with fructose, followed by manual cleaning with removal of all parts in contact with the product. In more detail, FIBCs with various raw materials are transported to the equipment, which is divided into two rooms. The product is discharged via HECHT FIBC discharge stations. Typically, a discharging station consists of four main components:

The connection system is the core component for a safe and low-dust or dust-free connection of the FIBCs. The product to be discharged is fed by gravity into a “suction shoe” - a special hopper for feeding a vacuum conveying system.

A Support Table supports the weight of the FIBCs and secures safe handling of suspended loads.

A Massaging Unit is used as discharging aid for poor-flowing products.

Frames are necessary for a safe mounting of the connection system and the FIBC. A pneumatic tensioning device is used to tighten the FIBC outlet as the FIBC is being discharged. Depending on the area of application, there are various additional options for system design and installation.

A chain hoist as well as a holding device are required to safely lift the FIBCs and position them above the connection system for emptying.

Large volume raw materials in the described customer project require discharge stations with FIBC connection systems and massage paddles. A HECHT suction shoe with lump breaker is used to break up any lumps in the materials.

Small volume raw materials and flavors are added via two semi-open combined sack/drum discharging stations. One sifter is used to screen hard crystalline products, while another ensures that lumps are broken up.

From the discharge stations the raw materials are conveyed by vacuum, utilizing two HECHT PCC700 ProClean Conveyors, into a 6000l Lödige Ploughshare™mixer manufactured by Lödige Process Technology. The transfer and feeding into the mixer is done continuously via rotary valves at the outlets of the PCC700s.

The HECHT PCC700 was specially developed to feed process systems, such as mixers, and filling lines with high production volumes. As a further development of the HECHT vacuum conveyor, the PCC700 meets the customer's high GMP and FDA requirements and enables safe and gentle conveying of raw materials as well as powder mixies. It creates a dust- and contamination-free environment, offers flexibility for installation in tight spaces, etc.

At first glance, the operating principle of the ProClean Conveyor 700 is hard to distinguish from conventional vacuum conveying systems: The vacuum conveyor is connected to a feeding point (here, for example, the FIBC emptying stations) by a pipe or hose, and the bulk material is conveyed by negative pressure generated by a vacuum pump. The transfer speed of the bulk material can be influenced, among other things, by regulating the conveying air supply. Depending on the conveying air setting and the product, various modes can be selected from lean phase conveying to plug conveying to dense phase conveying. With plug and dense phase conveying, segregation of the product can be avoided.

The high performance (up to 10 tonnes/h depending on the product) of the PCC 700 conveyors is mainly enabled by the four large filter elements and the large volume of the separation vessels. The (pulse-controlled) cleaning of the filters takes place in parallel with the conveying (the four filters are alternated so two filters are cleaned while the other two are used for conveying), allowing product to be continuously conveyed for a long duration and over long distances, filling the large separator vessel in a single suction cycle.

The conveying efficiency is complemented with a large filter area (up to 3.6 m²) and the resulting low filter load results in a low pressure difference over the filters. This enables effective conveying also of very fine-grain products (< 1μm). The low filter load also has a highly positive effect on the service life of the individual filter elements. The operator can quickly replace filters in a few steps without tools.

For the mixing process, a Loedige Ploughshare® mixer is used. This mixer operates according to the centrifugal and whirling process introduced into mixing technology by Gebrüder Lödige Maschinenbau GmbH, ensuring a consistent and very high mixing uniformity and short mixing times.

Ploughshare® mixing elements are arranged on a horizontal mixing shaft in a cylindrical drum. The size, number, positioning, geometric shape and circumferential speed of the mixing tools are coordinated in such a way that they set the powder particles in three-dimensional motion. The turbulence created in the mix - with the mixing tools constantly moving the entire material - does not allow the formation of dead or motionless zones in the mixing chamber, and results in fast and consistent mixing. The special shape of the tools lifts the powders from the drum wall in the radial movement and prevents particles from being crushed. For special tasks, it may be necessary to support the mixing action of the centrifugal unit. This is achieved by using separately driven high-speed rotating choppers which, in conjunction with the mixing tools, allow lumps and agglomerates to be broken down. The choppers also help evenly distributing any liquid to be introduced into the powder blend. To protect the mixer from metallic foreign elements, the conveying lines for FIBC raw materials and small components are equipped with horizontal metal separators.

After the mixing process, the discharge flap of the mixer automatically opens and the end product lands in another suction shoe. From there, the product is cyclically transferred to a filling line via another PCC 700 conveyor system. From there, drums and FIBCs can be filled for further processing. To ensure that the mixture is as homogeneous as possible without lumps in the end product, another screening machine is mounted underneath the PCC700, ensuring that any oversize particles are separated. Another integrated gravimetric metal separator guarantees the highest safety for the end product.

In order not to waste any product and to continue to work with low dust levels, a filling head with integrated trickle protection flap has been installed, so that spill of product onto the floor during a change of packaging material or when the system is idle can be avoided.

Features of the system design

It is possible to convey raw materials from one of the FIBC discharge stations or sack emptying stations past the mixer via a diverter to switch from packaging product A to packaging product B in the filling station. In this way, the process can also be "emptied" without having to empty the FIBCs through the mixing unit. The entire production is digitally traceable and documented according to current guidelines. Raw materials are visually scanned and approved for feeding into the mixer. An incorrect raw material would not be conveyed pneumatically, a correct recipe can thus be guaranteed.  Only two operators supply the lines with raw materials and packaging materials, the rest of the process is fully automatic. The overall plant itself has no down times as long as raw materials are fed and filled. The sophisticated time and recipe management and the integration of raw material feeding, mixing and filling realize a semi-continuous process.

Conclusion

Considering the complete system of low-dust filling and emptying as well as vacuum conveying, the system meets the very high demands on hygiene, safety and gentle handling of the product and the end user. The highest requirements for a closed process, which ensures dust reduction and avoids cross-contamination, are met by the various systems from HECHT Technologie. The systems can handle a wide range of requirements and applications for the supply of raw materials and intelligently integrate process steps in the food industry.

Kontakt

Hecht Technologie GmbH

Schirmbeckstr. 17
D-85276 Pfaffenhofen

T: +49 8441 - 8956 - 0
F: +49 8441 - 8956 - 56

info@hecht.eu

Please contact us directly >