Pneumatic negative pressure transport of powdery goods is ancient history. However things are different considering metallic parts with different shapes and high specific weight - such as at Johnson Controls, manufacturer of batteries.Johnson Controls is the worldwide leading manufacturer of starter batteries for cars, among them VARTA, the top brand. The required lead grids are manufactured at the VARTA factory in Hanover in fully automatic production lines: Melted plumb is formed in a roll train to a thin band, from which the grids are punched. This process generates much waste - small platelets in different shapes with a specific weight of 11,37 g/cm³ - which is returned into the production circuit.
These chads add up: About eleven tons have to be conveyed per hour, around the clock, over a distance of 50 metres with several 90°-bends to a height of about six metres. Up to now for the generation of the negative pressure required for vacuum conveying Johnson Controls used positive displacement blowers made in America. However, for Ahmad Abu-Shagra, Project-Manager at VARTA-factory in Hanover, these blowers have serious disadvantages: They are noisy, require comprehensive maintenance, susceptible to malfunctions and above all only comply with the German regulations after costintensive modifications. Therefore in 2010 when establishing a new production line for the factory in Hanover they decided for a positive displacement blower made by Aerzener Maschinenfabrik.
”A blower made in USA would have caused considerable modification costs in the drive- and safety area and additional expenditure for a reduction of the sound emissions. Therefore, after a costbenefit analysis for our new production line we used a new Delta Blower made by Aerzener”, explains Abu-Shagra. As with the current ”Generation 5” Aerzener Maschinenfabrik offers to the operator further advantages:
Wastes generated reach an intake pipe via a funnel and are returned to the melting process via a separator with rotary valve. Downstream of the separator now the Aerzen blower size GM 60 S has been installed for generation of the negative pressure. We bought it through Messrs. Georg Stein, specialist for pneumatic conveying based in Melle. Thanks to the uncomplicated construction of the blower its continuous monitoring is limited to the check of the negative pressure and the filter. The contact to Aerzener Maschinenfabrik was made via a colleague of Messrs. Johnson Controls in Hanover, who had participated in a meeting concerning admission pressure compressors. The visit to the factory in Aerzen was followed by the visit to a reference plant of an operator. ”The smooth running of this unit, the visit to the production plants in Aerzen and the extremely careful assembly impressed us”, assures Abu-Shagra. Afterwards, in close co-operation of all the persons involved, the concept originated.
”Since its commissioning the negative pressure transport system works perfectly“, reports Abu-Shagra. “We are expanding our production plants worldwide. Therefore colleagues from other countries visited our new unit several times already, and were very much impressed. Now we are checking the option to replace the negative pressure technology by overpressure pneumatic, where we also want to use machines made by Aerzener.”
»The contact to Aerzener Maschinenfabrik developed to a successful co-operation, which made the contact to other suppliers unnecessary.«
