Sealed degreaser handles 4 ton charges

UK heat treatment business claims to be the first to respond to environmental legislation by installing a hermetically sealed solvent degreasing system taking a 4 ton charge weight.

TTI Group claims to be the first UK heat treatment business to respond to the Solvents Emissions Directive (SED) legislation by installing an EVT hermetically sealed solvent degreasing system.

Formerly known as Senior Heat Treatment, TTI is part of the materials technology division of Aalberts Industries NV and has nine sites in the UK.

All these sites are ISO 9001-accredited, and specific sites also have other approvals such as NADCAP aerospace accreditation.

According to Martin Dyson, TTI Regional Sales manager: "TTI Group set up a project team to review the effectiveness and costs of component cleaning systems, whether existing systems or possible alternatives, and to assess the future costs and regulation of available systems.

It concluded that for heat treatment processes such as nitriding, Nitrotec and vacuum treatment, where the effectiveness of the pre-process cleaning is of paramount importance, the only cleaning process that satisfies the laid-down criteria is solvent degreasing".

The action led to a partnership developing between TTI, EVT Eiberger Pfohler and EVT's UK distributor, IB Industries of Bolton.

The outcome of their discussions was the installation in January 2007 of a hermetically sealed trichloroethylene solvent system with a charge size of 1600mm x 1600mm x 1500mm and a charge weight of up to a maximum of 4 tonnes.

These specifications make the system the highest capacity degreaser trike degreaser in a UK heat treatment facility.

This has provided TTI Telford with the equivalent capacity to its nitriding facility using a solvent spray and vapour process, with a regenerating carbon absorption system removing the last traces of solvent from the chamber prior to the finish of the cleaning cycle.

"The decision to choose EVT was based on the system's capability to satisfy new legislation, its robust design and its compact size," said Dyson.

"It is also energy-efficient and operationally effective by delivering the desired hourly throughputs.

These features combined with a competitive price, a bespoke design offering low maintenance costs, and UK-based after-sales service and support made the decision relatively easy".

The spraying system is optimally adjusted for the work pieces and it is also effective in rinsing off solids such as swarf, splinters, etc.

After the spray process the solvent is in a dirty state and is pumped directly from the cleaning chamber to the distillation to recycle the solvent to be available for the next load.

The solvent vapour is led into the working chamber where the solvent vapour condenses on the cold parts and degreases even the most complicated of shapes with the smallest of drill-holes.

This has provided TTI Telford with the equivalent capacity of their open top degreaser using a solvent spray and vapour process for all parts which need nitriding or Heat Treatment, said IB Industries to Manufacturingtalk.

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 air the opening of the sliding door is 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.

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 safetainer system.

IB Industries told Manufacturingtalk that EVT offers a broad range of these environmentally-friendly systems, from small, standard, sealed solvent cleaning systems to custom-made systems up to 4m x 2m x 2m capacity that satisfy all the requirements of the strict German legislation in place since the 1990s.

The EVT Gigant (Giant - Ed), for example, can clean and degrease large components or large volumes of small components within its 2m x 1m x 1m working envelope at a rate of 2 to 4 charges/h, 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.

* Fluid management - multiple filtration and oil distillation keeps the solvent free from contamination, and the cleaning and degreasing process is monitored and controlled via a 9in 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 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, TTI is benefiting from the high-quality cleaning performance of chlorinated solvents used in a safe and sustainable manner, said IB Industries to Manufacturingtalk.

It thereby complies with legislative requirements and contributes significantly to care of the environment.

* Consultancy - 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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