Application report type 4186

Neuschönau in the Bavarian Forest has a population of about 2200 and is an officially recognised health resort. It also has a large number of medium-sized companies, which generate a large amount of tax revenue for the community. One of these companies is BL Lasertechnik GmbH, which employs 40 people and provides laser cutting and other sheet metalworking services. Nitrogen is used as the cutting gas for laser cutting. Because there were problems within the vaporisation process with a valve from one of our competitors, the Bavarian company was one of the first companies to use the new HEROSE regulator Type 4186 – and was completely satisfied.

At BL Lasertechnik, liquid nitrogen is stored in a tank with a capacity of 10,000 litre at 37 bar and a heat exchanger converts the nitrogen into gas as necessary. Max Bauer, proprietor and Managing Director of BL Lasertechnik describes the problems before they were solved by the HEROSE Type 4186: “More or less nitrogen is required as a cutting gas, depending on the thickness of the sheet metal which is being cut by a laser cutter.”

Regardless of the quantity removed, the build up and reduction of pressure did not function reliably. Because of this, in some cases the pressure fell below the necessary 25 bar or increased excessively until it was blown off by the safety valves. Even though the pressure regulator was replaced several times, this did not solve the problem. The problems first occurred at the end of 2013. Even several immediate replacements of the normal pressure regulating valve did not remedy the situation. Bauer: “This was obviously due to our change to three-shift operation and the associated higher demand. The continual pauses and adjustment attempts were of course very annoying during periods where there was a large demand.” Together with Eberhard Zeller, the supporting sales representative, the technical department and the application engineer Marcus Moritz at the nitrogen supplier SOL the fault was searched for – and found. Bauer: “It was obvious that the regulation of the vaporisation process did not function properly.”

The problems disappeared

As SOL has worked with HEROSE for over 25 years, the problem was described and HEROSE was able to help. Moritz: “They offered us the new CombiPressureregulator although it was still in the testing phase.” The HEROSE Type 4186 offered precisely the functions which were needed in Neuschönau: pressure built-up and pressure reduction with an integrated safety function. After the regulator had been installed, the problems disappeared immediately – and never appeared again.
BL Lasertechnik produces sheet metal components for 350 customers in various sectors – for example for glass-making furnaces, for cable assembly machines as well as for industrial metal detectors. Bauer: “We offer various depths of production. These range from simple metal cutting to mechanical processing such as thread cutting, welding and milling up to the production of small assemblies.”

The main materials which we use are steel and stainless steel, each with a proportion of 40 %, followed by aluminium. BL Lasertechnik uses approximately 200,000 m3 of nitrogen every year and the monthly costs for electricity amount of about
€ 15,000. The history of the company and its proprietor Max Bauer is something of a “rags to riches” story from the Bavarian Forest. Bauer, who is now 45 years old, grew up in the neighbouring town of Grafenau, trained as a motor mechanic, was unemployed and began as a temporary employee with the town’s largest employer, Sedlbauer AG.

A “Rags to Riches” story

Bauer: “In those days I learned about welding and grinding – everything which you have to know for sheet metal working.” Bauer was ambitious. He trained in a second apprenticeship, qualified as a master craftsman and acquired a knowledge of business administration. Then came 1998. “At that time, Sedlbauer was faced with the question of whether to buy its first laser cutting system”, says Bauer. They decided against this, but asked me whether I would like to become self-employed as a supplier with such a company.” Bauer did so, expanded, and in 2012 constructed his business premises on the present site – and now hardly knows how he can fulfil the large number of orders. “Deally we would work a three-shift operation, seven days per week,” he says and smiles modestly.  Incidentally: He retains friendly ties with Sedlbauer AG, however they now only account for less than 3 % of his production – Bauer has become independent.

Photos: Carsten Wurr