The Paderborn-based company Gebrüder Lödige Maschinenbau specializes in the production and development of application-specific process technology and is a proven expert in basic process engineering operations such as mixing, drying, coating and granulating bulk materials. The company relies on the particularly robust and reliable Inoxline plug-in connections from Eisele for its ploughshare mixers and vacuum paddle dryers.

Application-specific process technology

Over 80 years of process engineering experience have gone into each of the customized mixers, dryers and reactors that Lödige supplies to the chemical industry and many other demanding sectors worldwide. With the development of the plowshare mixer in 1949, Lödige engineers achieved a revolution in mixing technology. Plowshare mixers achieve the highest mixing quality with short mixing times and outstanding product protection.

They work according to the centrifugal and vortex method developed by Lödige. The mixing material is always completely caught by the blades so that there are no zones with little movement. This technology allows various process steps to be combined, for example mixing, granulating and drying a product.

The versatile plowshare mixers are used in almost all industries for a wide variety of mixing tasks. They consist of a horizontal cylindrical drum in which the centrally mounted shaft, equipped with ploughshare blades, moves the product into a mechanically generated fluidized bed. Due to the intensive mixing and the resulting frequent contact of the particles with the optionally heatable apparatus wall, a high level of heat transfer can be achieved without local overheating.

The intensity of the particle movement increases during drying as moisture and viscosity decrease. Lödige machines are always specific special machines based on various basic types. Another design is the vacuum paddle dryer type DVT, which is used for various drying tasks in the chemical industry.

In these plants for the manufacture of various chemical products, some of which have very toxic and carcinogenic effects, absolutely safe containment is important to ensure that the environment is not contaminated under any circumstances. Protecting the people who operate the plants is also a top priority. Eisele's absolutely tight plug-in connections are a suitable component for this purpose.

Requirements in the chemical industry

In this application, batch mixing, granulation and drying take place in one and the same machine. Safety-related regulations such as explosion protection must be taken into account and an application-specific risk assessment must be carried out. The vacuum paddle dryer has a temperature control jacket that ensures gentle heating and therefore drying of the product in the process. In order to achieve faster drying at a low temperature, a vacuum pump generates negative pressure in the process chamber. This not only protects the temperature-sensitive product, but also supports safe containment, as no material can escape from the interior under negative pressure.

Lödige uses Eisele stainless steel compressed air connections from the 17A range to operate the paddle dryer, as the connections must be particularly tight and secure in order to prevent environmental contamination. The easy-to-clean design and corrosion resistance of the plug-in connections also play an important role in mixer applications in the chemical industry.

Stainless steel was therefore chosen to ensure optimum corrosion resistance and easy cleaning of all surfaces. The Eisele plug-in connections and the associated hoses are permanently installed on the system and only need to be removed for repairs or inspections. Thanks to the design of the plug-in connections, however, this is possible without any problems. The release sleeve of the push-fit connections with internal collet enables quick assembly and disassembly of the hose.

Priority for absolute tightness

The stainless steel connections can be used in a temperature range from -20 to 120 °C. Optionally, they can also be fitted with FDA-compliant seals that can withstand an extended temperature range. The reliable tightness of the components is of crucial importance, as product must not be allowed to escape into the environment under any circumstances. The special sealing technology of the 17A range with two FKM seals on the collet offers additional protection against the ingress of dirt into the system.

A chambered O-ring on the side of the screw-in piece ensures the necessary tightness between the machine and the connection. The stainless steel connections can withstand internal gas pressures of up to 24 bar, but are also suitable for vacuum down to -0.95 bar. Although many push-in fittings on the market are designed for high pressures, they are not automatically vacuum-proof.

The good workmanship as well as the high reliability and safety of the components are decisive and convincing features of the Eisele plug-in connections and not only convinced the client, who had expressly requested the use of Eisele components in his system.

The experts at Lödige are also highly satisfied with the components: "Eisele is exactly the right choice for demanding and safety-critical applications because the tightness and processing quality of the plug connections offer a decisive safety advantage," explains Reiner Lemperle, Sales Manager at Lödige.