Manufacturing Technology

AICHELIN Service has successfully optimised the thermal insulation of two industrial furnaces, after introducing new brickwork for the heat treatment plants of a different manufacturer.

As a long-term skills partner, AICHELN Service has been supporting Daimler Truck AG continuously with regular maintenance and repair works, as well as in projects regarding plant modernisation and optimisation. 

In Daimler Truck’s Gaggenau site, in Germany, there are numerous heat treatment plants by different manufacturers, among them several AICHELIN plants. For the current project, the brickwork for a LOI Thermprocess plant needed to be renewed and optimised. The goal was to replace the entire brickwork in a rebuild time of only six weeks, including disassembly and reassembly, while increasing the energy efficiency of the plant and enabling significant energy savings. The result was that AICHELIN Service was able to reduce wall losses by 10% – 15%, with the optimised insulation thus contributing to higher energy efficiency.

Optimised thermal insulation for plants 

Depending on the type and intensity of plant use, the thermal insulation, and in particular the brickwork in industrial furnaces, wears out after around 10 to 20 years and must be replaced entirely. The isothermal annealing system in question – a coherent, U-shaped installation consisting of one high temperature and one low temperature furnace – has been in use at the Gaggenau plant since 1971. The high temperature furnace is gas fired and achieves temperatures of up to 950°C; the low temperature furnace is operated with electric heating elements and reaches temperatures of up to 700°C.

To increase energy efficiency, the brickwork of the two furnaces should not simply be replaced 1:1. In addition to the complete renewal of the brickwork, the wall structure was to be reinforced and thermally optimised. Moreover, further customer specific energy optimisations had to be implemented. Temperature measurements on the systems before the start of the project provided additional indications of further optimisation potential, including around insulation, the burner flanges, as well as the outlet and door openings.

AICHELIN Service manages project

AICHELIN Service GmbH took over the complete project planning, coordination, and implementation, as general contractor. The time constraints in this project were especially challenging, as a very narrow time window of only 30 working days, including Saturday work, had to be met. To achieve this, AICHELIN Service successfully coordinated four project partners in order to perfectly align and execute the various works.

The project started in November 2022. After the dismantling of the heating elements by Daimler Truck AG employees, the excavation work, as well as other preparatory work, was carried out by AICHELIN Service and its partners, such as the removal and reassembly of the burner flanges, welding work, weld seam tests, and more. 

This was followed by the new brickwork and the reassembly of the heating technology before the subsequent test run in cold operation. The brickwork, with an optimised wall construction, was carried out with a suitably strong service team, which put together over 100m² of material ‘brick on brick’. In total, around 20 workers from the various partners, as well as the project managers and coordinators from AICHELIN Service and the customer, were deployed during the project. The final work was completed in December. The inspection and approval by the customer were carried out after the successful return to operation in late January 2023.