Steuler Surface Technology supplies Tunnel Pickling Lines with medium to high throughputs for wire, wire rod and pipes using a discontinuous dipping process. The process runs within a closed tunnel in order to prevent the escape of corrosive fumes, thus protecting both staff and equipment. The tunnel significantly reduces the exhaust gas volume too.

The automated lines are operated using treatment programs that can be flexibly configured to suit the most diverse of requirements. The concept allows for simple expansion should an increase in throughput or the use of other materials be required.

The cascade tank systems used for pickling and rinsing optimize use of the respective treatment medium and shorten the treatment time of the different materials and formats, resulting in high-quality surface finishes with low consumption of chemicals and fresh water.

The material is automatically transported through the various treatment tanks using manipulators or, in a monorail pickling line, using transport units that are program-controlled.

The main advantages are

• Few personnel required and plant operator protected from the treatment media

• Optimized chemical consumption

• High availability and high surface quality

• Low fresh water consumption, minimal fumes

• Automated line with almost unlimited number of treatment programs

• Easy expansion with increased throughput or use of other materials

Steuler Equipment Engineering's portfolio also includes Autoclave Pickling Plants for treating pipes. In contrast to Tunnel Pickling Lines, the items to be pickled are not transported through the various treatment tanks, but rather loaded into the empty autoclave that remains sealed during operation. Each of the required treatment solutions is then automatically added and removed according to a predefined program.

Autoclave Pickling Lines can be quickly, simply and economically adapted to accommodate changed throughput or quality requirements by installing an additional autoclave or exchanging and/or supplementing the existing treatment solution.

The main advantages are:

• Little space needed, few personnel required, simple to operate

• High plant availability

• Reduced wastewater volume thanks to cascade rinsing

• Low costs thanks to several process stages

• Variable cycle times, tank sequences and treatment media

• Minimal fumes thanks to system being closed

• Simple to expand the line to increase throughput or use other materials

Steuler Equipment Engineering supplies Roll Pickling Plants to the steel and stainless steel industry in particular for processing sheets, profiles, rods etc., because here the parts can be mechanically descaled via blasting first. In addition to reducing chemical consumption during the downstream descaling process, a good portion of the scale can be fed back into the manufacturing process as a raw material. This decreases resource usage significantly, which lessens the environmental impact appreciably and measurably lowers operating costs as a result.

The items to be pickled are continuously transported through the fully enclosed treatment stages via roller conveyors. The respective treatment solution is sprayed onto the material via nozzles. Different media can be used at each treatment stage and adapted according to requirements.

The treatment process can be easily and flexibly optimized while the line is running for all kinds of material by adjusting the treatment time (transportation speed), deactivating/activating a treatment stage and/or using different pickling media for the treatment stages.

In response to the demand for a reduction in NOx emissions and associated nitrate load, Steuler Equipment Engineering has developed a pickling solution for use in Roll Pickling Lines. It uses hydrochloric acid to remove the scale from stainless steel surfaces instead of the mixed acid HNO₃/HF. Besides greatly reducing the environmental impact, it results in improved surface quality and increased throughput while lowering operating costs.

The use of HCl as the pickling solution offers the following advantages

• No nitrogen oxides in the exhaust air

• Less sludge produced during the process as a whole

• Minimizes the cost of chemicals

• Shorter pickling times

• Lower capital investment and operating costs