A clean job: chip conveyors in the steel industry

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The deep hole drilling machines at BGH can be used for machining workpieces up to a length of 16 meters and a diameter of up to 1.6 meters.
The deep hole drilling machines at BGH can be used for machining workpieces up to a length of 16 meters and a diameter of up to 1.6 meters.

Reliable removal of steel chips and drilling oil ensures best possible production processes

The centrifuge is used for oil separation of short metal chips mixed with oil. The oil is propelled outwards and reintroduced into the cutting oil circulation. The “dry” chips are discharged in to a special container system. There are no downtimes for changing containers.
The centrifuge is used for oil separation of short metal chips mixed with oil. The oil is propelled outwards and reintroduced into the cutting oil circulation. The “dry” chips are discharged in to a special container system. There are no downtimes for changing containers.

From chipping come chips: this is equally true for the steel industry in particular. During the mechanical machining of the materials, the resulting high-tensile chips are additionally mixed with cutting oils – a combination which presents various challenges for removal and disposal of these by-products. This was also the case in the production systems of Boschgotthardshütte (BGH). The machines at the steel production plant in Siegen/Germany with a long-standing tradition are therefore equipped with chip conveyors from KABELSCHLEPP GmbH Hünsborn. Boschgotthardshütte (BGH) can look back at over 500 years of company history: BGH was already mentioned as the “hammer on the Ferndorf” in the year 1467. Production at the company outside the city of Siegen is still running today, with a portfolio that comprises an almost complete range of stainless steel products and special alloys for the highest requirements. The development of the owner-run, medium-size group of companies is characterized by stability and market focus. Customers particularly appreciate the competent advice, the customer service and the wide range of products in stock. The products from the BGH group are used all over the world: whether in industrial applications or in direct service for people – BGH stainless steel is in demand in many areas. The range of materials comprises all high-alloy and low-alloy steel types as well as special materials. “For centuries, forging was the actual task of the company,” explains Jost Kretzer, plant manager at BGH Edelstahl Siegen GmbH. “BGH now uses numerous other technologies to manufacture a wide range of products and materials.” Strategic investments in systems for hot molding and cold molding, tempering and mechanical machining enable the company to supply even small batch sizes.

Long chips are dropped into a separate container.
Long chips are dropped into a separate container.

Mighty dimensions for large workpieces
One of the machines for mechanical machining of the steels is a deep hole drilling machine from Schiess-Froriep. It allows the production of workpieces up to a length of 16 meters, a diameter of 1.6 meters and a weight of 50 tons, with a drill hole diameter of 50 mm to 1 meter. “These mighty dimensions are required for the production of pipes or propeller shafts, for example,” says Jost Kretzer. “But of course the machining of these large workpieces also produces vast amounts of by-products.” These are essentially high-tensile steel chips: Up to three cubic meters of spiral chips, flow chips and hooked chips have to be reliably removed per hour to prevent the production process from being affected. This process is further complicated by the drilling oil which is used as a coolant for the deep hole drilling machine. “With a circulating amount of approx. 50,000 liters there is a consumption of up to 2,000 liters per minute. It naturally cannot be avoided that chips and oil combine during the production process, forming a compound that is difficult to recycle.”

KABELSCHLEPP GmbH Hünsborn supplied a special chip removal system for BGH. The discharge conveyor has an overall length of approx. 43 meters and a max. conveying capacity of 9 cubic meters per hour.
KABELSCHLEPP GmbH Hünsborn supplied a special chip removal system for BGH. The discharge conveyor has an overall length of approx. 43 meters and a max. conveying capacity of 9 cubic meters per hour.

Robust conveyor for demanding tasks
It is obvious that the removal of materials of this type and magnitude has to be automated. A chip conveyor can handle this demanding task – but not just any conveyor, for only a particularly powerful model can fully meet the high requirements at BGH. “Due to the large amounts of oil in combination with small, adhering chips we had to supplement the good basic function with a functioning scraping system,” explains Jost Kretzer. This was made even more difficult by the fact that the deep hole drilling machine is installed in a water reserve area – so absolutely no oil may get into the ground. BGH had already treated the foundations of the production plant with a special sealant, but the chip removal still had to ensure that the oil is removed reliably and collected safely. During the search for a suitable model, BGH contacted KABELSCHLEPP GmbH Hünsborn on the basis of a long-standing business relationship. After all, there had already been good experiences with the company’s chip conveyors, as the plant manager recalls: “We already use different versions of these for our turning machines and paring machines.” Together they decided on a hinged belt conveyor from the SRF 100 model series in a special version. “Disposal solutions such as these require a specific configuration of the conveyor system and an accordingly adapted design of all assemblies to ensure safe operation,” as Uwe Becher, Senior Manager Project Planning at KABELSCHLEPP GmbH Hünsborn, explains. The hinged belt conveyor, for example, was equipped with a continuously adjustable drive system for a good reason. This allows precise setting of the delivery rate which is essential for the entire disposal process. “In addition to the purely functional aspects of the system, all safety requirements also have to be taken into account for these plants so that they can receive a CE marking.” KABELSCHLEPP GmbH Hünsborn delivered a turnkey chips removal system (including controller) as a complete machine in the sense of the Machine Directive 2006/42/EC.

The mighty dimensions of the deep drilling machine from Schiess-Froriep are required for the production of e.g. pipes or propeller shafts.
The mighty dimensions of the deep drilling machine from Schiess-Froriep are required for the production of e.g. pipes or propeller shafts.

Clever functions
The functioning principle is very clever: The material is removed using a hinged plate conveyor driven by a robust three-phase gear motor. A vibrating channel allows separation of long and short chips. The short chips are separated from the oil in a centrifuge with a speed of approx. 1000 rpm. The remaining oil is then filtered and reintroduced into the coolant circulation. Long chips on the other hand are dropped into a separately enclosed container. “To prevent downtime, we use two adjacent chip containers which are both equipped with a fill level monitor,” says Uwe Becher. “When one of the containers is full, they are automatically swapped over.” BGH is completely satisfied with the solution used – and they are not the only ones: Hinged belt conveyors from KABELSCHLEPP GmbH Hünsborn have proven successful at numerous customers in various fields of application. These robust models can be used as individual conveyors on machine tools or as linked conveyor systems. Depending on the version, the items are conveyed to the desired height at a defined incline and then discharged. For wet machining, the cutting oils are collected in the conveyor housing and then routed back into the machine circulation via an optionally available coolant container or a pump station. Uwe Becher states that “hinged belt conveyors can resolve the disposal issues in 80 % of all cases.” Whether wet or dry chips, refuse from laser cutting machines, warm forging parts, moldings or punching scrap – there is a suitable product in our range.”

Advantages of hinged belt conveyors from kabelschlepp gmbh hünsborn
-Sturdy sheet metal design
-Standardized housing section with variable width
-Robust shaft-mounted gear motor
-Conveyor length, discharge height and incline can be adapted to customer requirements
-Floor-mounted or as an insert into the machine bed
-Motor monitoring with current measuring relay, other overload protection devices on request
-Coolant container with pump station
-Direct electrical connection to the machine controller