Dangerous Dusts Binding Dangerous Dusts During Surface Treatment
Since the middle of 2017, Lissmac has been supplying its processing machines equipped with dry and wet separators from Esta. This was preceded by one and a half years of joint development.
Stefan Krummenauer, Product Manager Metal Processing at Lissmac Maschinenbau GmbH says: "Every grinding and deburring machine comes with an extraction system". The company from Bad Wurzach in Württemberg is one of the leading manufacturers of these machines. Krummenauer's business division manufactures machines for edge processing and surface treatment for customers in the manufacturing industry as well as for steel and automotive suppliers and service providers.
The deburring and grinding of steel, stainless steel or aluminium causes harmful dust. Therefore, the dust must be evacuated in order to meet the applicable occupational health and safety regulations. In addition, a process-supporting extraction system ensures a clean and dust-free machine operation. “This reduces the cleaning requirements of our systems, inhibits dust from depositing and eventually also prevents downtimes," summarizes Krummenauer.
Up to 20 Different Suction Systems
The joint development efforts of Lissmac and Esta Apparatebau GmbH & Co. KG began in January 2016: "With the expansion of our range of grinding and deburring machines, we had and increasing demand for compatible extraction technology. Before that, we only had two suction models in our program," explains Krummenauer. "That's how Esta came into play." The result: In the course of the cooperation, a new dry separator series (DDE) and a wet separator series (WDE) were developed. Philipp Reisser, project manager and OEM manager at Esta, gives concrete figures: "Today we can offer between 15 and 20 different extraction systems. Both series have capacities from ranging between 1,500 and 18,000 m3 per hour".
Purified Air is Fed Back to the Working Area
In what cases is a dry or a wet separator used? The answer to this always depends on the individual application, the material used and on the hazard assessment," says Krummenauer, specifying: "Every type of dust is potentially explosive. Ground aluminium, for example, is potentially the most dangerous dust”. Depending on the particle size, distribution and composition, this type of dust can form an explosive atmosphere. If an effective ignition source is added, there is always a danger of explosion. The term “explosion hazard” refers to specific work rules (in Germany DGUV Rule 109-001), which among other things list wet separators as a possible protective measure in order to prevent or minimize the dangers caused by aluminium dust. “With our wet separators, we can bind combustible dust such as aluminium dust in water, which ensures that the dust is no longer readily flammable," adds Reisser. This process is based on a sophisticated multi-stage wet separation system. The drive unit of the Esta separators is also designed according to ATEX in order to prevent the build-up of an explosive atmosphere on the fan. To this end, the drive unit is equipped with an electrically conductive housing. The entire equipment in the wet area comes with a highly effective H14 filter with a separation efficiency of 99.995% as a standard. In accordance with TRGS 560 (Technical Rules for Hazardous Substances), the cleaned air can then be fed back to the working area — even in areas where extremely hazardous dust is produced, e.g. during stainless steel processing," adds Reisser.
According to Krummenauer, customers more frequently order systems with suitably dimensioned dry extraction systems. “Of course, the decisive factors are the individual application and the available risk assessment," he points out and adds:" If, for example, normal steel is processed, we often link our plants to dry separators". In contrast to wet separators, dry separators are equipped with an integrated cyclone pre-separator, which protects the main filter media from direct exposure to dust and extends the service life," says Reisser. The permanent filter cartridges have a separation efficiency of 99.9 % and can be cleaned fully automatically by means of compressed air jets. The housing design of the two separator series is basically identical. Basically, they only differ in the applied filter and separation systems. For easy disposal of the dust, the dry separators are equipped with a collection drawer," says Reisser.
Since the middle of 2017, Esta has been delivering the new dry and wet separators to Lissmac — in the desired color and branding of the machine manufacturer. “We offer a reliable solution, consisting of machine and suction unit. About 95 % of our customers buy the total package," says Krummenauer. Reisser points out that all separators have suitable connections for the worldwide applications. With good reason: Lissmac has subsidiaries in the USA and China. All separators are connected directly to the respective processing machine via a pipe system, which also comes from Esta. Lissmac itself also uses the Esta machines for sheet metal working. “Actually, our development is only at the beginning. There is still a lot of demand for extraction solutions in this and other areas," says Krummenauer.
This article was first published by MaschinenMarkt.