Level radar works reliably for Aston Martin
08 May 2014
Aston Martin's paint shop effluent management system is benefiting from a VEGA radar level detection system recently installed at this iconic automotive manufacturer's plant. And if you would like to drive an Aston Martin, VEGA is offering a prize draw for readers - see base of article for details.
Non-contact radar works well even under these strongly foaming conditions
With a century of history, Aston Martin has developed into an automotive icon, a marque synonymous with luxury, heritage and authentic craftsmanship. All of their models are hand-built and bespoke, using high technology processes within a very modern environment.
The quality of exterior and interior detailing has always marked out Aston Martin from its rivals. Each of their cars is painted and finished by hand, receiving up to nine applications of paint — a process that takes more than 50 man-hours..
To ensure the paint finish on these iconic sports cars is perfect from every angle, all aspects within the Paintshop Facility must be controlled, even the environmental impact of the process. All the waste water is recycled, and one of the initial treatment stages in the recycling is the ‘Coagulation Tank’, where entrained solid materials are removed.
At the tank inlet, two large transfer pumps force the incoming stream downwards, heavily aerating the water to accelerate and improve the separation process. The coagulated solids settle at the bottom of the tank and the clean aerated water at the surface flows over a weir to be further treated and re-used in the Paintshop. The solids at the bottom are periodically pumped away for drying and disposal.
"This part of the Paintshop process is very important, it's one of those pinch points - issues in the effluent treatment can quickly affect the paint process, then we can't paint the cars, so production is directly affected", said Aston Martin's engineer responsible for these operations.
The ‘Coagulation Tank’ is approximately 3.5m deep, 5m wide and 8m long, with a strong effluent flow of up to 140,000 litre/min. Controlling the optimum level or stopping any overflow is crucial and not without difficulty, the surface is turbulent, it foams readily and heavily, build up on any form of 'contact' device quickly happens and causes problems.
After initially installing a guided wave radar, and trying point level switches, they found the heavy, unpredictable high build up levels and contamination were so severe on the probes that it caused false readings and needed frequent cleaning.
The poor measurement availability and high maintenance were unwelcome in such an important area. The ‘Coagulation Tank’ is very hazardous, the heavily aerated water means that anyone falling in would sink ‘like a stone’, so minimising any personnel working in the area is a safety priority.
The VEGAPULS WL61 radar level sensor
Almost 2 years ago, the units were changed for a contactless VEGAPULS WL61 radar level sensor by the Aston Martin team. Designed for water and waste water applications, it features an IP68 housing with an encapsulated antenna, ideal for the harsh operating environment in an effluent plant.
This being the first occurrencein a Manufacturing scenario, the sensor is ideally suited as the liquid density and substances contained within the liquid have no bearing on measurement accuracy.
Most importantly, the device can cope with all reasonable levels of foam due to the excellent signal sensitivity and the 80mm antenna, which focuses signal for optimal performance.
"The readings we now get are to the millimetre, which is extremely accurate and allows us to have a greater level of control, especially as this measurement also governs the ‘Water Make Up Valve’ which operates to re-level the Tank as water evaporates due to the process," the engineer reports. "All of the control strategy for the Water System was re-written after installation due to the greater level of accuracy and so far we have enjoyed a 100 percent efficiency rate to date.
"The safety surrounding the ‘Coagulation Tank’ has also been increased as we don't have to enter the guarded area around thetank to clean off build up. Being non-contact is ideal in this application, so if the pit is cleared out, we don't risk any sensor damage either."
VEGA is offering a lucky reader the chance to experience this automotive icon for themselves, by winning a track day to drive an Aston Martin at one of five UK locations. If you send in your details, discuss an application or request a brochure, you will be entered into their prize draw. For terms and conditions please contact VEGA. Draw will be closed on 31st December 2014. Contact info.uk@vega.com 01444870055 ask for the sales team.
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