Daxner GmbH, Schüttgut Technologie

Daxner's innovative concept meets highest requirements for a modern bakery ingredient mixing facility - high throughput, utmost dosing accuracy, reduced dust generation and cross contaminations, easy cleaning inclusive CIP-cleaning and ergonomic operation.

This can be achieved by the pneumatic feeding of large components in combination with a fully automated container system for the collection of medium and small components.

DESCRIPTION

Daxner has designed a flexible, automated blending and dosing system for the production of various ready-made bakery ingredient mixes, which consist of a very large number of different ingredients, such as sugar, various flours, starches, cooking fat etc.

Daxner developed an innovative system with due regard to easy cleaning, dust-free powder handling and prevention of cross contaminations, in order to exclude reciprocal contaminations.

A decisive criterion is the strict separation of components, which contain allergens, from those products, that are allergen-free.

Project objectives:

• Design and delivery of a high performance mixing plant for the production of bakery ingredient mixes for bakery products (bread, cakes, cookies, confiture etc.) in compliance with state-of-the-art regulations. Prevention of cross contaminations, most notably of those handled ingredients which contain allergens.
• The following ingredients are handled without any contaminations and mixed homogenously:
  • Large components such as flour, crystal sugar, dextrose etc.
  • Medium components for example salt, sugar, starch etc.
  • Small components such as bread improvers, emulsifiers, spices etc. 
• High capacity up to 12 t/h ready-made mixes
• Maximum prevention of cross contaminations for all handled allergens, certified in accordance to BRC-regulations (=contamination free production below 10 ppm)
• Easy cleaning of the equipment in compliance with the regulations of COP (Cleaning out of place), dry-cleaning and CIP-cleaning, i.e. the automatic wet cleaning based on the principle Cleaning in Place. Depending on the hygienic concept, the best suitable cleaning system is selected.
• The Daxner Container-Handling System (DCS) allows a flexible product or production changeover.
• Highest mixing accuracy (1:100.000) for powder mixes inclusive the addition of block fat resp. liquid fat.
• Ergonomic design
• Prevention of dust generation

Process technology

All ingredients are divided in large, medium and small components. Large components are stored in outdoor silos and are pneumatically conveyed to the two mixing lines. Medium components are stored in daily silos which are fed by mobile intake stations with intregrated control screens.

The medium components are then dosed and weighed out of the daily silos into the below positioned container or IBC (Intermediate Bulk Container) by the means of a dosing screw conveyor with rough and fine dosing which is connected to the silo discharge device. A highly precise active and passive valve system enables the fully automated connection to the filling opening of the IBCs.

The mobile intake station VIB&PRESS (inclusive control screen and stirring device) fills the pre-commissioned small components directly into the IBC.

A three-dimensional container transport system, which consists of an automated storage and retrieval system with chain conveyors and a shuttle-system, conveys the IBCs fully automated to all collecting points (medium and small components), subsequently to the mixing line and finally to the discharge of the collected product batches. The IBCs are docked on and off at these stations. The mixing plant consists of a high precision vertical blender. The blending principle is based on a reverse flow which is generated by a rotating screw belt in the mixer. Block fat is dissolved in the mixer through cutting rotors. The geometry of the screw belt ensures that the product always runs through the cutting rotos.

A producer of stabilizers for the foods industry assigned Daxner for the planning, delivery and installation of a gravimetric blending system equipped with two separate mixing lines.

DESCRIPTION

The newly installed mixing line of Daxner serves as a core module for the production of high end powder mixes for the foods industry.  The concept design was developed with regards to the specific situation of the start-up company. In line with the available budget volume Daxner planned, delivered and installed a complete gravimetric mixing system equipped with various components in hygienic design, which provides energy efficiency, high flexibility for product changeovers and easy cleaning. Another essential objective was to ensure utmost mixing accuracy and to enable a gentle and hygienic addition of micro ingredients. This was achieved by reducing cross contaminations in order to maintain product quality. Also the minimization of cleaning times and a design for minimum overall operational costs was taken into consideration.

Blending

All small and medium components are solely pre-commissioned in the corresponding allergen rooms. These rooms are physically separated from each other in terms of the handled allergen and therefore they only permit access with hygienic, protective clothing. Subsequently a forklift truck positions the bags and the pre-commissioned small and medium ingredients onto the operating platform. There, the operator fills the ingredients into one of the two existing VIB & PRESS bag intake stations.

Depending on the product characteristics the mixing system itself is specifically selected. Line 1 is equipped with a horizontal paddle mixer and line 2 with a horizontal ploughshare mixer, in order to provide highest flexibility for various mixing jobs.

The control screening machine operates according to the principle VIB and PRESS – an innovation from Daxner. In doing so, it encompasses two major processes: The vibrating screen sieves the product (VIB) and simultaneously slowly rotating paddles press the product through the flat screen (PRESS), in order to gently dissolve agglomerations and lumps. Even if small mesh widths are used, the screen remains free of any residues and at the same time it enables its cleaning due to its vibrations. The drive is provided by a geared motor with variable speed through frequency converters. The tilt-up mechanism of the entire top part ensures quick cleaning. Also the implementation of a permanent magnet grid is possible for the elimination of magnetic contaminations. This system screens products with poor flow characteristics respective products which tend to clump or with high fat content by incorporating small mesh widths and reasonable throughput.

The mixer is designed according to the EHEDG- standards with two large cleaning doors. The mixing system enables a high mixing accuracy (higher 1:100.000) and short mixing times ranging from 1 to 5 minutes. Also extremely different ingredients (bulk density, particle sizes and structure) can be added to the mixing process.

Bag filling

The finished mixes are discharged into the corresponding mixer receiver bin, which holds the entire mixing capacity. Receiver bins are in hygienic design and equipped with a vibro discharger – in combination with a pressurized air cleaning in the discharge cones – which ensures their residue free discharge. The implementation of the mixer receiver bins enables a fast discharge of the mixers and additionally provides a buffer volume for the below positioned bag filling station. Therefore the number of batches and consequently the plant performance is notably increased.

Below the mixer receiver bin the finished mixes are filled into packages ranging from 15 kg to 25 kg by using a bag filling and weighing system, called DAX-PVS. This completely gravimetric and compact designed bag filling station combines a simple, semi-automatic handling with high throughput and easy cleaning (no residue!).

The product intake station VIB & PRESS is used for the intake and control screening of powdery products, especially for difficult products which tend to clump.

VIB & PRESS is the principle used for this control screener, which is an innovation from Daxner. Two actions are performed at once: Additional to the vibrating screen (VIB) which performs the screening action, the products are pressed through the flat screen (PRESS) by slowly rotating paddles located just above the screen mesh. Agglomerations and lumps in the products are dissolved gently. The vibration keeps the screen free of residue and cleans it at the same time.

The paddles are driven by a geared motor with variable frequency drive. The entire top of the machine can be removed by a simple tilting mechanism, which enables a fast and easy cleaning. Optional design with a controls systems and complete wiring "plug & play" also available.

Also a permanent-magnet for the separation of magnetic impurities can be incorporated.

Container Systems contain the handling of bulk solids using containers (IBC’s). The IBC transport within the system can be implemented according to specific requirements by forklift, powered roller-tracks, automated guided vehicle or stacker cranes.

Container systems include the following processes:

• Storage – dosing of raw materials (small components)
• Filling – weighing of raw materials into batch-containers
• Mixing/blending inside the container (gravity blender, container blender)
• Loading and intermediate storage of metered batches in containers
• Container discharge into packaging machines

SPECIAL ADVANTAGES

• Maximum on flexibility
• Elimination of cross contaminations
• Customized solutions
• Automatic, exact dosing of small batches down to grams
• Controls with visualization, protocols, and complete traceability of batches
• Residue free container discharge
• Easy cleaning of containers
• Optional fast disassembly features of discharge and dosing equipment (dosing screw conveyors etc.) for quick cleaning
• Optional design for the foods-, animal feed-, chemical- & plastics-industries
• Optional dust explosion rated design (ATEX)

As one of the leading spice blend producers in Europe the company produces more than 4.000 different spice blends. The innovative plant design impresses with high efficiency and reliability. Daxner Container Systems DCS ensure an automatic handling of the products.

DESCRIPTION

Complete solution across 5 production levels

The system design ranges over 5 levels and covers the whole production process: from the storage of raw materials in outdoor silos, the transport to the daily silos, their filling, dosing, weighing and the mixing process through to the discharge in IBCs (Intermediate Bulk Containers).

All processes run completely automated and meet the highest standards in regard to quality, performance and flexibility. With this customized concept design the requirements for a plant capacity of 80t/day in a 2 shift operation (16h/day) can be easily fulfilled. Given the large number of orders with a small batch size and a large number of components, this represents an outstanding achievement. In addition, the plant encompasses the contamination-free changeover of a variety of recipes which consist of a wide range of different component weights.

8 daily silos (large components) are fed by external silos, another 30 daily silos (medium components) are loaded by bag dump- or big bag intake stations. Below the daily silos, 20 scales are installed which are assigned to the daily silos according to the product characteristics.

Corresponding to the specifications of the final product, one scale can be loaded from one up to four daily silos. The system ensures an accuracy of ± 50 g, based on a net weighing range of 500 kg. Due to the weighing accuracy, components with more than 5 kg are weighed automatically. Components with less than 5 kg or which require a higher precision are stored and managed in an automatic storage and retrieval system for small and micro components.

In accordance with the job control, components are retrieved automatically from the automatic storage and retrieval system and are then fed to the manual dosing station. These individual components are weighed operator-controlled into a trough with barcode-identification. Subsequently, the order-specific troughs return to the automatic storage and retrieval system for interim storage.

The IBCs in DCHD (Daxner Container Hygienic Design) are fed by 3 intake stations. There the prepared, palletized complete bags (bag commodity, buckets, cartons) are retrieved and order-related loaded.

Innovative Container transport system DCS

The key to higher efficiency of the plant design can be seen in the IBC transport system. Profound arguments for Daxner Container Systems DCS in conjunction with an Automatic Guided Vehicle system (AGV) are the following:

• higher number of batches
• maximum flexibility
• prevention of contaminations

In total, 60 IBCs are used which are transported by the Automatic Guided Vehicle through the whole plant. The empty IBCs are taken out from the conveying system and are positioned automatically below the corresponding scale by the AGV. These can be controlled via laser and positioned accurately at the discharge points to within ± 15 mm. For filling, the IBCs are lifted, afterwards docked by the Daxner Container Docking Station DCSC and finally filled.

After weighing the components in the weighing bin, the filling of the IBCs can start with high performance. Subsequently the automatically dosed components are collected, whereupon the IBC is positioned underneath the manual intake stations. There all small components are dumped as complete bags and/or as a subset from the automatic storage and retrieval system. Once the manual components are added, the IBCs are picked up by the AGV system, then conveyed with a lifting device to the level above the mixing lines and finally positioned with an electric fork lift truck on the Daxner Container discharge stations.