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Western Technical Services | Accusense Systems International Limited |
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Spray Dryer Inspection
WTS have been inspecting spray dryers in the Food, Flavour and Pharmaceutical industries for 15 years and have a wealth of experience in this field.
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No risk of damage to the Spray Dryer from Scaffolding poles. |
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No risk of splinters or debris from wooden planks. |
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No blind spots below scaffold pole supports which have not been tested. |
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Less downtime |
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Cost savings |
Meeting British and European Standards
Our new access platform as far as we are aware, is the only mobile access platform for spray dryer inspection currently in use to meet the British and European Standards for Suspended access equipment in accordance with BS-EN 1808.
We have a wealth of experience of spray dryer inspection of over 15 years and currently test approximately 30 spray dryers per year throughout Europe.
All its inspections are carried out by highly trained and qualified personnel. Its technicians are certified to PCN level 2 or 3 or SNT-TC-1A level 2 or 3. Both of these internationally recognised certification schemes comply with EN 473 - The European Standard for the Qualification and Certification of NDT personnel.
What is best for you?
There are two NDT processes that can be used for the internal inspection of spray driers, vats and tanks:
- Liquid Penetrant inspection
- Eddy Current examination and derivatives.
There are of course advantages and disadvantages of both processes.
Spray Dryer Gallery
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WTS Trial
WTS recently conducted a trial to evaluate both processes. This was carried out on a 10 metre diameter spray dryer. The liquid penetrant inspection was carried out using WTS own bio-degradable Fluorescent Penetrant and conducted by Richard Rossiter. The Eddy Current examination was carried out by Mr Aaron Wicks utilising the array probe technique for the examination of the circ and vertical weld seams where the surface was flat and the bridge probe technique for the top and bottom weld connections where the surface was not flat. The recommended scanning speeds when carried out by suitably certified personnel is array 20 mm per second which only needs to be carried out in one direction. For the bridge probe 150 mm per second but in four different directions to cover all defect orientation.
Note: It is not possible to use the array probe technique unless the surface is completely flat to enable contact of all the probes.
Timescales:
- Liquid penetrant inspection was carried out of a 100% of the internal surface including explosion doors and attachments in 4 hours.
- Eddy current was carried out on the circular and vertical seams only in 7 hours
Defects located:
- Liquid penetrant inspection - 12 off crack like indications between 3-40 mm in length, 10 gas pores.
- Eddy Current examination - 8 off crack like indications between 8-40 mm in length. No gas pores located.
Mr Wicks explained the reasons for the differing results were that his only option was to use a bridge probe on the top and bottom shell to end plate welds. It is not possible to locate defects less than 5 mm when using this probe. This is because the probe contains two coils which are 5mm apart, both of which need to be in contact with a defect to confirm its existence. Therefore it is not feasible to locate defects of less than 5 mm.
Final Conclusion:
The liquid penetrant process was far superior. It located more defects, in a far shorter time and the whole internal surface of the dryer was examined. Clearly the Eddy Current process when utilising the bridge probe technique is not reliable for locating smaller defects which in the liquid food industry could be critical. As the bridge probe technique is the only option for shell to end plate welds and outlets, which is where the majority of cracks appear, we as a quality orientated company recommend liquid penetrant inspection for the inspection of spray driers, vats and tanks.
In other industries and applications we use Eddy current very successfully. We always recommend the right inspection technique for the right reasons.
Recent Experience
Recently we were asked to inspect a tank with a known leak in it. This vessel had been inspected twice in one day by another company utilising an Eddy Current technique or derivative. On both occasions they were unable to locate the leak. We went in the following day and utilising the liquid penetrant technique we located 6 off cracks, one of which was 40-50 mm long and in the outlet! Imagine what this cost and suffice to say they will not be employing this inspection technique or company again.
Ask yourself, is it better to use the correct inspection process and personnel and get the job done right or use the incorrect process by unqualified personnel which could end up costing you a lot more money or worse in the end.
Above trials conducted by:
- Richard Rossiter - Quality Director
- Aaron Wicks - Quality Manager
Qualifications:
- SNT-TC 1A Level 3 (Liquid Penetrant Inspection)
- SNT-TC-1A Level 3 (Eddy Current Examination)
Food & Beverage
For the thorough and definitive testing of plate pack heat exchangers, WTS have developed and patented its own unique non-destructive testing method utilising Helium gas.
Our Clients
Western Technical Services has worked with some of the leading companies in the UK, Europe and the United States.
Client Testimonial
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