Aerospace tube business responded to the Solvents Emissions Directive (SED) legislation by installing an EVT hermetically sealed solvent degreasing system.
The Salisbury -based company has numerous approvals from leading aerospace companies, among them Rolls-Royce, Airbus UK, BAE Systems and GKN Aerospace, and while specialising in bespoke and small batch work has the capability to handle the longer runs and repeat orders typical of volume production.
“It was decided that the EVT system gave them the best chance of compliance with their long term requirements while offering excellent degreasing results at a very competitive price”.
According tothe companys Environmental Manager, the decision to invest in the new EVT degreasing system came after a careful analysis of the many alternatives available, both aqueous and solvent-based., This decision led to a partnership developing between the customer, EVT GmbH and EVT’s UK distributor, IB Industries.
which resulted in the installation of a hermetically sealed solvent system with a large chambers. The larger aerospace tube profiles were fixed in an adjustable basket which accommodates a 3000 mm x 600 mm x 600 mm rotatable basket, available for complex tubes with blind holes on various faces. The chamber with immersion initiated by the program on a operator screen allows smaller components to be cleaned and degreased effectively by a more efficient combination of movement and immersion capacity.
The spraying system is optimally adjusted for the work pieces and is also effective in rinsing off solids such as swarf. After spraying the solvent is pumped directly from the cleaning chamber for recycling ready for the next load. Solvent vapour is directed into the working chamber where it condenses on the cold parts, degreasing even the most complicated of shapes with the smallest of drill holes.
A regenerating carbon absorption system removes the last traces of solvent from the chamber prior to finishing of the cleaning cycle. For adherence to the legal regulations, the system is equipped with a concentration measuring instrument, which monitors the solvent concentration in the working chamber at regular intervals. Only after falling below the concentration value legally designated of 1g/m³ of air is opening of the sliding door possible. If the activated carbon of the adsorption unit is saturated with solvent, it can be regenerated automatically by hot air in operation with the circulating air.
“The EVT machine is easy to use via the touch screen interface,” says Works Director, “and the equipment seems to be reliable and robust. The maintenance procedures were explained at the commissioning stage and all aspects of the project were handled very well. In the eight months since installation the machine used approximately 300 litres of solvent, which is a vast improvement on previous performance.”
In order to keep the oil rate of the solvent small and thus the cleaning quality high, the distillation of the solvent is indispensable. The oils brought in usually have a high boiling range and remain therefore in the distillate swamp. This can be disposed off emission free in the gas pendulum procedure in the SAFE-TAINER™ system.
EVT offers a broad range of these environmentally-friendly systems, from small, standard, sealed solvent cleaning systems to custom-made systems up to 4 m x 2.5 m x 2 m capacity that satisfy all the European legal requirements. The EVT Gigant, for example, can clean and degrease large components or large volumes of small components within its 2 m x 1 m x 1 m working envelope at a rate of 2 to 4 charges/hour, with vapour and optional stages of spray, immersion and ultrasonic. It is designed as either top or front loading and can rotate or oscillate components at any stage in the cycle.
Multiple filtration and oil distillation keeps the solvent free from contamination, and the cleaning and degreasing process is monitored and controlled via a 9-inch touch screen. Carbon adsorption and solvent concentration controlled to less than 1g/m³ guarantees compliance with SED and European VOC requirements, while additional features such as vacuum distillation, vertical parts movement and activated carbon filter systems are easily integrated into the EVT system if required. The EVT range, which features stainless steel construction allied to high quality welding procedures, also includes fluid management facilities that can be interconnected with the SAFE-TAINER™ system provided by SAFECHEM, a subsidiary of The Dow Chemical Company.
This SAFE-TAINER system comprises two separate containers each with a standard drum inside, one for fresh and one for used solvent. With the steel container protecting the drum from damage or spills, the SAFE-TAINER system is both integrally bunded and portable, ensuring safe and simple on-site storage and transfer. With a few simple connections, fresh and waste solvent transfer is easily and safely achieved within a virtually sealed system.
By installing a hermetically sealed solvent degreaser from EVT in combination with the closed-loop SAFE-TAINER system, the company is benefiting from the high-quality cleaning performance of chlorinated solvents used in a safe and sustainable manner – thereby complying with legislative requirements and contributing significantly to care of the environment.
As a supplier of chlorinated solvents, SAFECHEM offers a range of consultancy and other services that enable customers to effectively manage the product specific risks of solvents and to apply Chemical Management Services to the entire life cycle of the chemical.
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