Optimum boiler construction
Diagonal stays instead of stud bolts
In other boiler designs the reversing chamber is fixed to the boiler end with stud bolts and there is no direct connection between the flame tube and the boiler end. Especially when heating up, large forces exist in the boiler due to the temperature difference between the cold boiler shell and hot flame tube. With stud bolts these forces can only be transmitted at specific points which leads to unfavourable stress peaks.
Further disadvantages of stud bolt construction are:
- Stud bolts critical when exposed to bending stresses
- Bolts tear off, especially with frequent temperature changes
The design principle of Bosch industrial boilers has been further developed and the stud bolts omitted. The flame tube is anchored to the boiler shell at both ends and can distribute stresses evenly via the boiler base and diagonal stays (corner anchors). To avoid additional thermal emissions, multi-layer Bosch composite insulation with a particularly high insulating effect is used for the boiler inspection door. A further benefit is the lifelong freedom from maintenance, assuming proper operation and commissioning. This UNIVERSAL UL-S design has proved itself in more than 80,000 boiler systems for well over 60 years. A number of these boilers which were initially produced from the early 1950s are still verifiably in operation today.
The symmetrical design minimises stress during the manufacturing process and whilst the boiler is in operation. The large flame tube and the arrangement of the flue tubes enable efficient heat transfer with low emissions.
High durability
The concentric arrangement ensures uniform heating, even when the boiler is cold, and minimises stresses within the boiler. The design principle employed allows for a low water content, enabling the boiler to reach its operating temperature more quickly.
