KELLER HCW builds new brick factory for the ZAO "Pawlowskaja Keramika" company in Pawlowsky Posad, RUS
[September 2008] Already in April 2008, KELLER HCW handed-over a newly constructed brick factory to the owners of the ZAO "Pawlowskaja Keramika" company in Pawlowsky Posad. The modern new building replaces the factory which was originally located on this site. A detailed description of the new brick factory situated near the Russian capital Moscow can be found in the following.
The place
Pawlowsky Posad is a town with approx. 65,000 inhabitants about 70 km east of Moscow. The town, which had already been named in the 14th century, is mainly shaped by the textile industry. Furthermore, agriculture, a food company, some smaller companies as well as the brick factories are the economic factors of this town.
The brick plant
Traditionally, bricks have been fired in Pawlowsky Posad for more than 100 years. The clay is conveyed from the company-owned pit and then prepared in the factory.
For the new installation the old brick plant was completely dismantled. Due to a design contract placed in advance with KELLER HCW it was possible to adapt the existing factory halls in time and to use them again.
The project
A completely new production plant for the manufacture of 60 million facing bricks has been constructed on the site of the existing brick factory. The machinery and installations can be optionally increased to an output of 75 Mio. NF–units per year.
A wide range of sizes corresponding to the given nomenclature can be manufactured in the factory whereas the installation supplied allows for the production of special sizes and shaped bricks.
The basic raw materials for the manufacture of facing bricks are clays from the existing pit, which are refined with additional clay and sand as well as other aggregates. There is also the possibility of adding manganese, titanium oxide or other additives.
The necessary raw material testing, as well as the determination of the optimum material mixes, has been carried out in KELLER’s in-house ceramic laboratory in Ibbenbüren-Laggenbeck.
For the design of the factory by KELLER HCW GmbH the important criteria adapted to the local conditions have been determined jointly with the owner.
• Optimum utilization of the factory area
• Assurance of quality and quantity
• High availability of the plant
• Power reserves for unforeseen breakdowns
• Appropriate flexibility of the plant for size changes
• Low investment costs
• Low maintenance costs
• Lower need of spare parts
• Efficient usage of energy for the operation of machines, dryer and kiln
• Optimum working conditions for the operating personnel
These requirements could be met by the extensive use of quality components, sufficient output design to achieve safe operating procedures as well as by user-friendly working procedures.
In May 2006 the contract for the supply of a complete plant with machinery, dryer and kiln was signed at KELLER HCW in Ibbenbüren-Laggenbeck.
Plant description
Machinery for the brick production (wet side)
As the drying of bricks is done in a conventional tunnel dryer with dryer car and pallet loading, the machinery was designed accordingly:
The continuous clay column is cut into individual products by means of a universal cutter with electronic cam disc. Optionally, it is possible to chamfer the wet products on four sides by means of an additional switchable device. A further refining of the clay column can be effected by the integration of a surface finishing machine.
Therefore, the conveyor between the extruder die and cutter is designed to be moveable on tracks.
A gap is created between the products on a grouping conveyor to improve the air circulation during the drying process and then transferred by means of a pallet automat onto pallets ("laths") arranged in pairs.
The loaded pallets are then collected in layers by means of a grouping chain conveyor. Dependant on the width of the clay column it is possible to have different centre to centre distances. After grouping is finished the pallet rows are loaded in layers into the tunnel dryer car by means of a special lifting and moving device.
Tunnel dryer
The tunnel dryer is equipped with a wet storage and 4 drying tracks.
The handling of the dryer cars loaded with products is programme dependent effected in cycles. The dryer is equipped with inlet and outlet sluices to maintain the drying climate. As a special feature it is possible to store dryer cars entering or leaving the dryer outside the dryer by means of a double-sided operating transfer car.
Jet walls are used for the air circulation necessary for drying. The drying air is blown between the products and then circulated by means of slot nozzles installed in vertical sheet metal walls between the dryer cars. The required heat energy comes primarily from the kiln waste air or from auxiliary burners and is then fed to the dryer via radial fans.
The tunnel dryer is separated into 4 climate zones according to the respective moisture content.
The saturated wet air is fed back to atmosphere via axial fans installed in wet air stacks.
Electrically driven control valves are installed in the air channels and ducts to control the supply air and waste air flows.
By the use of pressure, moisture and temperature measuring devices it is possible to control exactly the air and temperature within the tunnel dryer adjusted to the respective state (e. g. when changing sizes).
The control of the dryer and the tunnel dryer track system is effected automatically by means of a freely programmable process computer. Consumption and status data can be called up at any time.
Format dependant drying curves are retraced fully-automatically, synchronized with the actual value and adjusted if required.
Setting machine
Sequentially to the dryer car loading, the laths loaded with dried product are removed in layers from the dryer car and deposited onto a chain conveyor. A robot removes the products from the pallets and places them on feeding conveyors to the setting machine.
By the use of V-belt conveyors, stoppers and holding clamps the empty laths are collected in layers. A transfer device takes the pallets to the inlet conveyor of the lath machine or stacks them on corresponding frames for intermediate storage.
Conveyors handle the products simultaneously in two rows to the setting machine inlet. Here they are collected to counted rows by means of a holding clamp and carriage. A lowerable turning device allows for turning onto the cut face. The product rows are transferred to the setting machine table, designed as a belt conveyor, where a row grouping system provides the necessary firing gaps between the products. Above the kiln car two four-axis handling robots remove the grouped rows in layers from two staggered take-off tables and set them in a cross-bonded setting onto the kiln car.
By the use of the most modern materials, mechanics and sensors, the special layer grippers as light and robust robot tools are an essential part of today’s current handling devices.
Special sizes can be transported on a separate transport conveyor to a manual setting station behind the automatic setting machine. Here it is possible to set these sizes manually on top of the load which has been set automatically.
Top fired tunnel kiln
After drying the next procedural step in brick manufacturing is firing. This is effected in a tunnel kiln divided in the following areas: preheating zone, firing zone and cooling zone.
The kiln building is an essential and, with reference to energy savings, also an important part of the kiln plant. From the outside to the inside it consists of facing brickwork, an insulation consisting of vermiculites and mineral fibre as well as refractory brickwork. An integrated steel skin gives an air tight operation.
The handling of loaded kiln cars to be fired through the kiln is effected by a hydraulic pusher installed at the kiln inlet. The pusher indexes the tunnel kiln cars pack by pack through the firing channel.
In Pawlowsky Posad the preheater is positioned as a separate unit next to the kiln inlet to reduce the factory length. Here the residual moisture is driven from the dried products and they are prepared for the heating and firing process.
The tunnel kiln has been designed with an inlet and outlet sluice to maintain a continuous pressure and flow ratio since a certain pressure profile is necessary for the control of the flue gas and air flows.
Due to the products to be fired the kiln was constructed as a classic top fired unit. Only the pre-fire zone is equipped with laterally arranged high velocity burners. All burners developed by KELLER HCW are certified according to the Russian standard.
In the firing zone, energy is supplied via an injection burner plant installed into the kiln ceiling. It is equipped with a central gas and air supply system.
The burners are combined in groups; each of them servicing two firing channels. The last burner group is designed as a "Flashing unit".
After the firing zone the cooling zone is the end of the tunnel kiln where fresh air is blown into the firing channel by means of a fan to cool the fired bricks. A part of the hot air is drawn off and used – in an energy-saving way – to heat the dryer. The remaining pushing air flows through the kiln in the direction of the kiln inlet and in this way the flue gases generated in the firing zone are used to heat the green bricks in the heating zone. The cooled flue gases are drawn off at the inlet end of the kiln and fed to atmosphere via a flue gas stack.
The complete kiln plant, as well as the kiln car handling system, is equipped with automatic measuring and control devices. A process computer system is used for process control.
Particular emphasis is put on to safety systems. Separate switching and monitoring devices are installed for security-relevant functions.
Unloading – packaging
Since special sizes can also be manufactured in the described plant it is possible to move the kiln cars with the fired bricks after the kiln exit onto a side track where the special sizes are unloaded manually and can be stacked onto the provided pallets.
The standard sizes are removed in layers from the kiln cars in the regular unloading position by a robot and set onto a belt conveyor. From here the bricks are transferred in rows by a so called lifting roller cross conveyor onto two plate chain conveyors and go through the sorting line.
For pack forming the bricks are grouped and then the rows are put together in layers.
An industrial robot stacks the brick layers on pallets. Also intermediate paper layers can be inserted by the robot by means of the specially designed multi gripper with suction device. Furthermore, the dispatch pallets are also removed from the pallet stacks by the robot and put in the pack forming position.
The completed dispatch packs pass the film hood machine where the shrink film hood is fitted as a protection from the weather. The packs are then doubled and put on a magazine chain conveyor for collection by a forklift.
Control
The control of all machine and plant components as well as the preparation and shaping plant is effected by a switch and control centre with PLC SIMATIC S7 designed and produced by KELLER HCW.
Coordinated components and standard interfaces give a smooth operation.
Another advantage regarding production and operation reliability is the worldwide teleservice of the KELLER HCW plants. In case of faults, diagnosis of the reasons behind machine or operating faults can be achieved quickly – after system release by the customer. The availability of automation and process guidance systems are essentially improved. If necessary, the service specialist can directly influence the control of the plant, which also allows for the subsequent consideration of customer’s requests.
Teleservice permits the remote visualization and control of the plant, programming of the process control computer and the programmable logic control (PLC), specific analysis of operating and fault messages as well as file transfer, software updates and documentation.
Project data
Working times:
50 weeks/year
7 days/week
2 shifts/day
9.5 h/shift
Reference size:
NF–facing bricks according to GOST No. 7484-78 and EN 771-1
250 × 120 × 65 mm with 42% perforation
Output of the reference size:
60.000.000 NF-facing bricks / year
1.200.000 NF-facing bricks / week
171.430 NF- facing / day
9.023 NF-facing brick / hour
Additionally, the following sizes have been considered:
250 × 120 × 88 mm with 42% perforation shaped bricks
Solid bricks with a perforation of up to 6%
Further information can be found under the following links:
Press Release 04/2008 »
Press Release 08/2006 »
Press Release 05/2006 »
Project data of the plant »
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