From S to XXL – clean hardened components safely and cleanly

High functionality combined with security packages

In order to make steel and cast iron components more resistant for their later use, they have to be hardened.

Depending on the hardening process, the production auxiliaries used and the intended result, degreasing processes are used which are individually adapted to the size and weight of the components to be cleaned, the type of loading and the appropriate cleaning agent.

EVT Eiberger Verfahrenstechnik GmbH develops and manufactures customized systems for the residue-free removal of production aids for hardening shops around the world.

The design of a cleaning system for a hardening shop is very demanding.

It depends on many parameters, because on the one hand the range of parts can range from the size of a screw to the size of a shaft for ship drives. The process steps upstream and downstream of cleaning are also relevant.

Extreme environmental conditions, such as high temperatures or open barrages at the hardening furnaces, are sometimes added to the cleaning system. For parts cleaning, this means, among other things, that there are no flammable residues on the parts or other interactions between cleaning media, deposits, gases etc. and the kilns.

Costa Burkhardt, Head of Sales at EVT:

There is no off-the-shelf machine for the requirements in hardening shops. The often limited space in a hardening shop, the immediate vicinity of hardening furnaces, the special features of component geometries, the process steps before and after – our wide-ranging process competence in the various industries, which is a prerequisite for the highest product quality in component cleaning, combined with decades of experience in mechanical engineering, helps us to take all special parameters into account optimally. The result is individually developed cleaning concepts that are perfectly tailored to the requirements of hardening shops. ”

Suitable cleaning medium
Choosing the right cleaning medium in hardening shops is a difficult task. EVT recommends the use of non-flammable solvents such as Perchlorethylene (PER), which has the advantage over the use of modified alcohol or non-halogenated hydrocarbons that the risk of deflagration in the hardening furnace is excluded. Costa Burkhardt: “This can happen if components do not come out of the cleaning system 100 percent dry because, for example, they are very scooping. In this case, bores, depressions and other cavities are holding the cleaning medium on the components. These then, possibly directly, move into the hardening furnace. Flammable media pose a danger to life and limb here. ”
If non-flammable solvents such as chlorinated hydrocarbons (CHC) can be used, the immediate vicinity of hardening furnaces to the cleaning system is harmless. In this way, the available space in the work hall can be used optimally.

Costa Burkhardt: “For us, safety is paramount throughout the entire development and construction process. That means, depending on the cleaning medium and process, we equip the system with the corresponding EVT safety package. Examples are our air purification systems as well as the special explosion protection packages. ”

A good example is transformation hardening, in which the components are quenched in an oil bath. The challenge is that after the components come out of the hardening furnace or quench bath, they have to be cleaned of large amounts of oil.
This means a major challenge to the cleaning process in order to remove all residues from the components. In EVT systems, which sometimes require a chamber volume of 9,000 liters of cleaning solution for hardening shops, special processes are used that can process the high oil input and yet have an ecologically and economically sensible consumption of solvent.

Leak-proof loading technology via front-top loader

In addition to the appropriate cleaning process, the loading of the cleaning machine for hardening shops plays a special role, since the degreasing systems are often integrated in hardening lines.
Typical front loaders harbor the latent risk that solvents can escape in liquid form or as steam if the chamber door is opened unintentionally. EVT developed the leak-proof front-top loader for systems that require front loading from production processes. EVT front-top loaders combine the convenient front loading of the system with the safety of a working chamber loaded from above, whose maximum solvent level is below the loading door. In this way, accidents involving solvents, such as accidental or incorrect opening of the door, due to a technical defect or an operating error, are excluded, according to the EVT.
Costa Burkhardt: “We offer high-quality, specialized solutions for all branches of industrial production and, as the example of the hardening shops shows, we develop individual system configurations that are tailored to very special customer requirements. This creates trend-setting, safe cleaning machines that work optimally in such demanding environments. This not only makes our customers’ production processes safer, it also increases quality in terms of the requirements placed on their products. ”