New preservation line for steel products

A new preservation line for steel products replaces the existing blasting and preservation system at a steel trader. It provides temporary corrosion protection for a wide range of steel workpieces.

In order to meet customer requirements even faster, more flexibly and more efficiently, Carl Spaeter Hamburg has expanded its machine park with the KON 34/6-HD blasting and preservation line from the manufacturer Rösler. It is designed for processing steel products up to 3,200 mm wide and 400 mm high with a length of up to 21.2 m and is equipped with two color systems. Optimally integrated into the existing hall and crane concept, the new line not only enables highly productive operation, but also ensures a significantly improved material flow and therefore shorter delivery times.

Founded in 1905 as a Hamburg ironmonger, Carl Spaeter Hamburg has established itself as one of the leading steel partners for trade, craft and industry in the north. The north extends far beyond northern Germany. Success factors include a wide range of steel products with a continuous stock of over 25,000 tons of steel, fast delivery, high agility and extensive processing options. "As our existing blasting and preservation system was getting on in years and we wanted to further improve the service for our customers, we replaced it with the KON 34/6-HD from Rösler," explains Mike Barz, Managing Director at the Hamburg-based steel trader. The plant manufacturer from Untermerzbach prevailed against two competitors, with the flexibility in implementing customer requirements as well as the quality and robust design of reference plants being the decisive factors. "Rösler worked with us to develop a viable overall concept in a very short space of time, which is precisely tailored to our circumstances and requirements," reports Reyk Hagelberg, Operations Manager at Carl Spaeter Hamburg.

One of the key requirements was that workpieces up to 3,200 mm wide with a length of up to 21.2 m and a height of up to 400 mm could be processed. It had to be ensured that sheets from four millimetres thick could be blasted with the same high quality and process reliability as those 100 mm thick. The reliable blasting and painting of all corners and edges of profiles was also one of the specifications. The maximum workpiece weight is twelve tons. The roller conveyors and cross conveyors of the transport system were designed to be correspondingly robust. Sensors detect the height and, in the case of sheet metal, also the width of steel products on the infeed roller conveyor of the preservation line. The number of blasting turbines is automatically adjusted to the values determined. Other parameters, such as the throughput speed and the color and thickness of the coating, are stored in the system control as processing programs that are selected manually. The parts then first pass through a preheater, which prevents moisture from entering the blasting system and supports rapid drying after painting.

They then move on to the blasting system. It is made of manganese steel as standard, and there are also interchangeable, overlapping plates made of the wear-resistant material in the blasting chamber. Here, eight high-performance Gamma 400G turbines, each with a drive power of 22 kW, ensure that the blasting result of SA 2.5 is reliably achieved at a speed of up to 4 m/min. Thanks to the Y-design throwing blades, the turbines achieve up to 20 percent higher blasting performance compared to conventional turbines, while at the same time reducing energy consumption. Adhering abrasive and dust are reliably removed by the downstream brush and blow-off system.

In order to be able to respond to individual customer requirements when coating with water-based primer, the automatic painting machine integrated into the line has two independent application systems. Before painting, sensors determine the workpiece dimensions with millimeter precision and the painting bridges are then automatically adjusted to the respective part dimensions. As a result, primer is only applied in the required layer thickness where it is needed. This makes a decisive contribution to a resource-saving working method and minimizes overspray, which is directed into the paint filter by the suction system on both sides. This works so effectively that the residual dust content of the exhaust air is only 0.2 mg/m3, which is usually between 1 and 2 mg/m3.

At 1 mg/m3, the residual dust content of the exhaust air from the blasting process is also well below the legal requirement of a maximum of 3 mg/m3. "With the new preservation line, we are able to carry out high-quality surface treatment of sheet metal, profiles, pipes and steel bars in an efficient and environmentally friendly manner," adds Reyk Hagelberg. Heating the dryer with exhaust air from the preheating system also contributes to resource-saving operation.

The transport system for the new preservation line was integrated into the existing hall and crane concept at Carl Spaeter. The roller conveyors, which can be moved forwards and backwards, extend across all four bays of the 42,000 square meter hall and enable flexible loading. This means that steel products can be easily transported from any area of the hall to the preservation line, to another area of the hall or for loading onto a truck. The cross conveyors positioned to the right and left of the roller conveyor also offer plenty of space for buffering workpieces. "With the new system and the resulting additional processing options, we can meet our customers' requirements faster and more efficiently and offer a high level of planning reliability thanks to significantly shorter delivery times. The system, in conjunction with the roller conveyors and cross conveyors, also saves our employees having to travel long distances and ensures that work processes run smoothly," concludes Mike Barz. (OM-6/24)