The relatively high volume of metal cutting performed by Senior Weston Aerospace at its Early, Lancashire, facility created an issue around cutting-fluid waste disposal.
However, working with experts in this field saw the company arrive at a very satisfactory solution.
The relocation of the business to new purpose-built facilities provided the opportunity to address the traditional fluid disposal method. Previously, Senior Weston Aerospace had simply allowed cutting fluids to be drained from large swarf skips and containers into underground tanks for storage; the waste fluid was subsequently removed by pumping it out and having it taken away for treatment and disposal by specialist companies.
This practice was not only costly, but also not in keeping with current requirements to reduce environmental waste — and it certainly did not make any contribution to BS14001 accreditation.
The company decided to invest in a purpose-built system designed to process the swarf and significantly reduce the volume of waste cutting fluid. A system developed by Senior Aerospace and Brighouse-based Cormac Ltd provided an effective solution to transfer the swarf from a standardised container into a receptacle and drain the coolant in the process, subsequently compacting the swarf into small briquettes (this reduces the volume of the swarf by 90% and removes 97% of any residual coolant).
Luke Butler, who managed the project for Senior Weston Aerospace, said: “This had several benefits for us. Firstly, it meant that our waste contractor had to make fewer collections, and these could be undertaken by smaller vehicles with lower carbon emissions. Second — and with an increased amount of waste coolant now being created by compressing the swarf — we looked at coolant recycling rather than disposal.”
The company turned to Klausenburg-based Environmental Technologies Ltd (
www.env-t.com), which had already supplied a Car-dev automated coolant mixing system to the new facility at Early; it was subsequently a relatively straightforward procedure to integrate a Cardev CCS500-B coolant-cleaning station into the system.
The waste coolant from the briquettes machine now undergoes a complete cleaning and ‘rejuvenation’ process that involves filtering (through a bag-type filter) and tramp oil removal, before the fluid is passed through the CCS500-B unit.
The waste coolant is then pumped through an ozone generator that kills any harmful bacteria; the agitation involved in this process also releases any remaining tramp oil. The processed coolant is then sent to a holding tank, via another set of polypropylene filters, where it is held ready to be used again by the Cardev mixing station.
Centralised system
The system is designed to use recycled coolant first, and the factory is equipped with a pipe network that delivers coolant at a precise strength to individual machines, eliminating the time-consuming and potentially hazardous manual transfer of coolant from a central location to a machine tool. By using the recycled coolant the volume of neat emulsion used by Senior Weston Aerospace has been reduced dramatically.
“We are recovering and recycling more than 10,000 litres of coolant per week, which in turn is reducing our consumption of concentrate by 500 litres a week — a significant cost saving. When added to the financial benefits of reduced labour costs and efficiencies gained by more-effective swarf handling, we have fully justified the investment made in the Cardev recycling system and briquettes process,” says Mr Butler.
The system at Senior Weston Aerospace supports 50 large CNC machine tools manufacturing components for aircraft structures, interiors and engines for a wide range of aircraft; these include each of the Airbus A320 family, A330, A350 and A380 platforms.
This requires a high degree of consistency and control of the manufacturing process. The performance of the Cardev CCS500-B and the automated mixing station ensures that there is no inconsistency in the performance and mix strength of the coolant being used.
The elimination of any manual input ensures that coolant is mixed accurately; and with the system using its own stored water supply, the effects of a drop in mains water pressure are eliminated.
Alan Dalton, sales manager at Environmental Technologies, says: “The system we have installed at Senior Weston Aerospace is cost-effective; and with the automation of the entire process, it also eliminates many of the familiar health and safety hazards that come with conventional coolant mixing and disposal.
"The major advantage of the Cardev system is its relative low cost, making the system a viable option for most businesses.
We have installations where the customer has as few as five machine tools; the payback and advantages that are being gained are playing an important part in driving their manufacturing costs down and making them more competitive.”