Rewe Group

The Rewe Group is one of the leading trade and tourism groups in Europe. The Group currently employs 320,000 people in 16 European countries. The external turnover in 2008 was €49.8 billion with €33.95 billion generated in Germany alone. In Germany, the REWE Group operates the supermarkets REWE, REWE Center, REWE City, the self-service store toom, the specialist stores toom, Baumarkt DIY Stores, B 1 DIY Discount and ProMarkt, the toom beverage shop as well as the travel agencies ATLASREISEN, DER, and DERPART. Austria is the main foreign market with the supermarkets BILLA, MERKUR, the PENNY discount stores and the BIPA drugstores. REWE is also active in France, Italy, the Czech Republic, Hungary, Slovakia, Russia, Romania, Croatia, the Ukraine, Bulgaria and Poland. In total, the Group operates almost 15,000 stores. 
The REWE Group, founded in 1927, still has a co-operative organization structure. The turnover generated by independent retailers under the REWE umbrella in 2008 amounted to €8.38 billion.


Glocken Bäckerei

The Glocken Bäckerei was founded in 1904 as a bakery named Glockenbrot. It was acquired by REWE in 1986. This bakery has turned into one of the leading suppliers of bread and baked goods in Germany, generating a total turnover of about €160 million , REWE has now four production companies including the facility in Bergkirchen. The parent company is located in Frankfurt/Main employing 700 bakers work in three shifts. The bakery acquired the chain store bakery Hindermann from Bergheim, near Cologne in 2004 and this was followed by the chain store bakery Rothermel in Östringen in 2009. The Glocken Bäckerei serves several distribution channels within the REWE Group as well as approximately 250 of its own bakery outlets and about 150 shop-in-shop stores.


Factbox Glocken Bäckerei

Lot size   40,000 sqm
Total floor space   28,200 sqm
Cubage   219,600 cu m
Number of floors   2
Maximum length of the building   234 m
Maximum width of the building    83.9 m
Height of the building   10.5-12.3 m
Clearance in the production area   5-8 m
Ground breaking   28.10.2008
Roofing ceremony   15.5.2009
Inauguration   20.1. 2010
Total investment   €80 million
Staff   400
Annual flour consumption   36,000 tons


Technology in Bergkirchen

Bread slicer Planet 3000 V²A

The long bread loaves are sliced with a tendency-controlled slicer with a 750 mm rotating circular blade. The one-row machine can produce up to 500 slices per minute. It is equipped with a new oil-saving and mould-protecting oiling device for the circular blade. The amount of oil is controlled by parameters entered into the program. An automatically height-adjustable set of springs ensures proper adjustment to the respective height of the bread.
The setting of the slice thickness (e.g. 8.00 mm) is tendency-controlled and coupled to an independent check weigher and an integrated electronic metal detector. The slices’ thickness can be adjusted in 0.1 mm steps depending on the weight determined during production.
The machine also features an Ethernet-compatible PLC and a 12” touch screen is provided for program selection.


Dough strand equipment Format 3000 V²A

The total usable length is 3000 mm; up to 350 dough strands can be formed per minute. The special Teflon-coated extruder is equipped with a gate for precision dough division by weight. The extruder is swivel-mounted for easy access during operation and maintenance.
It is also tendency-controlled and coupled to the weigher of the dough strand line. Via feedback the load cells control the nominal weight during the dough division process. 
The Ethernet-compatible PLC controls the optimum amount of dough based on the strand weights determined. Flour dusting from above or below can be separately selected and controlled.
A three roller system including a sheeting roller smoothes the dough strands; the strand heads are retained by dough limiters. Two additional dusters/seeders allow the uniform distribution of the flour or other toppings on the dough strands.
In total, 28 different recipes can be stored in the PLC and then selected via a 12” touch screen. The stored system parameters ensure reproducible and reliably high quality.


Proofer and thermo-oil tunnel oven

The proofer is 5 m high and 15 m long. It has two levels with six decks each, i.e. 12 decks in total. The split proofer has a total proofing area of 2 times 180 sqm. In comparison the oven has a baking area of 150 sqm. The lining inside the proofer has a thickness of 75 mm. The proofer is made from stainless steel inside and outside. Both levels of the proofer can be walked for maintenance and cleaning work.
In the lower six decks, the round dough pieces are deposited on polyester felt belts. The products, when placed on a loading table, can be transferred in one step. In the upper six decks, the oval-shaped dough pieces are placed in polyester felt moulds. The transfer is done mould by mould.
Both levels are equipped with air conditioning columns on the sides for uniform air distribution. The air flows through the decks transversally to the moving direction of the dough pieces. The steam supply available at Glocken Bäckerei is used for heating the circulating air via heat exchangers. The wetting is also done with steam. If the circulating air has to be cooled, it passes another heat exchanger that is operated with cold water.
All units are available twice in order to condition the levels independently. Two loaders feed and remove the dough pieces.
Two more loaders feed and remove the dough pieces from the MIWE thermo-rollomat tunnel baking oven equipped with hinge-plate belts. The total baking area is 150 sqm. The boiler for heating the thermo-oil is located on a separate steel platform above the oven.


Silo plants 

Currently a total of seven production lines for the production of toast bread, loaves, pan bread, rolls and small wheat pastries as well as sourdough are supplied with raw materials. Planned capacity expansions have already been considered in the plant design.
The plant predominantly consists of
  • 8 outdoor silos (50 tons each) for the storage of different types of flour
  • 3 in-line screening stations including error detection for sieving the ingredients arriving from the outdoor silos prior to their use in the production
  • 2 central weighing stations for the flour from the outdoor silos, consisting of buffer, weighing and pneumatic conveying container for feeding of the mixing systems
  • 2 stations for medium components consisting of a different number of indoor storage silos, central weighers and pneumatic conveying containers for feeding the mixing systems
  • Various pneumatic conveying systems
  • Unit for milling and recycling of toast bread ends at the slicers
  • Discharge stations above the individual mixing systems
  • Metering units for oil and shortening
  • Control and switching unit consisting of control cabinets dedicated to the respective line’s main groups and discharge stations including profibus interfaces.

Advantages of the implemented equipment concept

With this equipment concept, Reimelt consequently implements the storage and weighing of raw materials, separated by type and volumetric production consumption.

Almost all flours are screened prior to processing and intermediate storage. Via electronic control measures (Screen-D-Tect®) the sieving processes are continuously monitored. 
Due to the early participation of Reimelt in the equipment concept and building design, the weighing stations can be arranged in such a way as to allow free flow weighing processes using an arrangement of the containers at proper heights. In this way energy-saving concepts could be implemented at the planning stage. The allocation of all storage containers to the weighing systems provides for complete flexibility of the raw material feed to the mixing systems.
For future expansion more central weighing stations can simply be added. In the manufacture of the container and filter technology, the focus was placed on hygienic design.
With the open configuration of the control and switching unit for the handling of solid ingredients optimal linking and integration into the total control of the bakery is possible.


Process control

The process control system Plant iT V8 by PRoLeit, Herzogenaurach, controls the entire production, assures proper reporting and provides for the traceability of products according to the IFS standard. Interfaced with the ERP system of REWE, incoming orders can initiate the respective production process. 
Batch iT is the core module; it was developed especially for recipe-controlled processes and adapted to the production of baked goods. In Batch iT, the ingredients of a recipe and the production specifications are depicted and processed separately. This way the system ensures high flexibility in case of recipe changes or production process modifications. In order to select a product at the beginning of the metering process, the system first shows the list of raw materials and then the processing parameters in a separate list. After both have been linked, the product specific control is activated. 
The separation of the ingredients list and processing parameters dissolves the rigid separation of recipes and metering units or equipment and facilitates changes. At the same time it guarantees that new equipment and processes can be easily integrated into the control program. The separation of different parameters ensures that individual metering steps no longer follow a strict order. The access to silos and metering plants is controlled in such a way that the metering and dosing units are optimally used to capacity. 
With the implementation of Batch iT, the weighing of dry components as well as the metering of liquid components could be done with standard load cells which do not need any separate programming. Batch iT also handles the new water mixing unit with different control and cut-off valves, the liquid yeast dosing and the temperature control. 
The operator stations at the respective machines and lines are also integrated in the ProLeit system allowing for a uniform visualization layout for the respective parameters and ensuring quick and easy comprehension of the important data. At the same time each line unit can be operated from the operator station so that the line staff can react immediately to error messages or operating information and confirm them. The system follows a hierarchic organization so that each operator can only see and control what is permitted in his or her position. The shift foreman has the authority over all lines. 
The ProLeit hardware is also based on standard components. Apart from a main server, a Siemens S 7 is used as central PLC.


Multi purpose bread line

An industrial multi purpose bread line by Rondo is operating in the Glocken Bäckerei. The line is 25 m long, 1.2 m wide and has a capacity of more than 2 tons per hour. The line is designed in such a way as to produce different types of bread and rolls with very gentle dough handling. The line is used to produce different types of ciabatta, baguettes with pointed ends, rolls with seeds and rolled-up bread. One special feature is the production of rolls with seeds as four different types of these rolls can be produced at the same time. This is made possible with a special sprinkling station by Rondo which allows for the use of different toppings for each row on the belt.
Bread and rolls are produced on the Rondo bread line as follows:
After batch proofing, the dough is passed via a dough chunker to the dough sheet former Oscar. This dough sheet former is characterized by very gentle handling of the dough. It produces a homogeneous dough sheet which is then gauged with a Rondo satellite head with two bottom rollers. Here again, gentle dough handling is important; the satellite head is equipped with 16 rollers which are arranged in a diameter of 495 mm. The satellite head is additionally equipped with two bottom rollers providing for very gentle rolling in two stages.
The downstream cross roller is used to sheet the dough sheet across its width and to eliminate possible longitudinal stress. Here again the Glocken Bäckerei has made a point in gentle dough handling because the cross roller is tapered and has a rather large diameter of 200 mm.
After longitudinal cutting, the dough strips are moved onto the spreading belts with tilt resistant double bridge guides to the guillotine. The Rondo high performance guillotine has a cutting width of 1,200 mm and performs 200 strokes per minute. It was important to the Glocken Bäckerei that the exchange of cutting tools at product change-over could be done easily and quickly. For the production of baguettes with pointed ends, a special tool with angle-adjustable blades is used.
Downstream of the guillotine are two exchangeable units, a moulder and a seeder. The moulder is used for roll-up bread and baguettes with pointed ends and as a bypass for ciabatta. When producing seeded rolls, the moulder is replaced by a seeder which allows the production of four different types of seed rolls at the same time. Prior to seeding, the dough pieces are wetted with water. After that the products are automatically placed on proofing trays and transported into the proofer.



The dough is produced in Bergkirchen predominately with Diosna Wendel mixers with roll-out vats. The Wendel mixers are characterized by two mixing tools located off center which turn in opposite directions to each other and are moved from above into the vat that is also turning. Due to the special helix shape, the dough can be produced quickly but still gently with only low temperature development.
New developed tools also make this process interesting for smaller dough quantities. Once the vat is filled to at least one third, the mixing tools can apply all the advantages of the Wendel mixers. The mixing intensity is increased, the mixing time reduced and the dough hydration improved by 1-2%. 
The mixer is available for batches of between 160 and 600 kg dough with fast dough change-over resulting in hourly performance rates of 5,000 kg. 
Upstream of the Mecatherm baguette line, both Wendel mixers, with bottom discharge, form a tandem from where the line is continuously supplied with dough. The raw materials are automatically fed into the mixing vat. After the mixing time has elapsed, the dough is discharged through the mechanical opening at the bottom to a belt conveyor and moved on to the dough divider.


Crate washer

The crate washer by Colussi, Casarsa della Delizia, Italy is tailor-made. The crates are transported through a pre-washer, a main washer with alkaline bath, the first flushing section, a second flushing section, a station where the water is blown off and finally through a hot air drying station. Zero residual moisture is guaranteed. Water filters before and after the main washing step make sure that dirt particles are separated and disposed of. In principle, the cleaning takes place with a large volume of circulating water and not with the application of high pressure. A precondition is the supply of soft water, for example, from a reverse osmosis plant. 
The entire housing of the plant is made from 4 mm stainless steel. All welding seams are absolutely smooth so the plant could be used in pharmaceutical applications. The top part of the housing can be lifted up electrically for easier inspection and repair, if needed. All nozzles are fixed individually to stationary arms and may be replaced one by one as needed. The top and bottom part of the plant are designed in such a way so that no sealing is required.


Bread lines

The Kaak Group played a key role as a supplier to the Bergkirchen factory. The Group delivered not only three complete lines but also the dough make-up of the shop bread line, all the Teflon-coated bread pans, the entire bread conveying equipment to the packaging stations of lines 1-4 and partly for lines 5 and 6 (ciabatta and baguettes) as well as the entire conveying system for the transport crates. 
The toast/sandwich bread line which can produce 6,000 toast breads and 4,500 sandwich breads per hour starts with the Dough Master by Benier. This is a five pocket dough divider with an unusually wide weighing mechanism (490 mm) for handling larger dough volumes. The five pockets ensure the smooth operation of the dough divider. A hopper with gate is positioned above the dough divider. This way the dough pressure on the blades of the dough divider is subjected to fewer deviations which promotes the weight accuracy. Downstream of the dough divider is the check weigher Dough Controller. Its data flow is linked to the software of the dough divider which allows the programming of not only nominal weights but also standard deviation tolerances. 
The following Tall-Round is a combination of a cylindrical and a conical rounder designed for high performance and offering the possibility of introducing air which makes the dough surfaces less sticky. The line is completed by a pre-proofer, a belt moulder, a walk-in proofer for moulds and finally an MCS oven with two burners and a net baking area of 3.75 x 34 meters. The baked breads are then cooled down for two hours in a double spiral tower. 
The Multi-Click line by Kaak is used to produce traditional mixed bread of different weights (500, 750, 1000 g). Up to four different baking pans are mounted on a square rod so that the current bread mould can be exchanged at the push of a button. Here again, a Dough Master by Benier performs the division and a belt rounder and a sheeter with a belt running in the opposite direction shape the bread. The sheeter can also function as a seeder, if necessary. The proofing takes place in a step proofer; for baking, a Daub multi-level thermo-oil oven is available.
In combination with the Herlitzius bread strand former, this line can also produce long bread loaves with a maximum length of 1,300 mm.
The third line, supplied by Kaak, is a pan bread line on which four different sets of pans are used for baking the products in an MCS oven. The dough make-up is done in a Dough Master by Benier. A short belt rounder and a sheeter with a belt running into the opposite direction shape the dough which is then placed into Teflon-coated mould sets in which they travel through the step proofer. A portal robot handles the pans including storage and acceptance of returned pans from the depanner. The pan storage is positioned above the oven. 
All three Kaak lines are equipped with so-called human interfaces. 19” monitors at the line allow the operator to display the entire line, to localize, visualize and remedy possible errors and faults.


photo gallery

Line 01: Toast bread



Line 02: Loaves and sticks


Line 03: Shop bread


Line 04: Pan bread



Line 05: Ciabatta



Line 06: Baguette


Opening ceremony



Colussi: Crate washer



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