Enamel dust filter clogging problem solved

Edited by the Processingtalk editorial team Aug 10, 2007

Donaldson Membranes ePTFE filter media has given a new lease of life to a filter employed in the production of dyestuffs for the ceramics industry at Colores Ceramicos, situated in Castillon, Spain

Colores Ceramicos, an expert producer of dyestuffs and serigraphy for use in the ceramic industry, is committed to on-going research and development to ensure maximum performance of their processes.

As part of this drive for continuous improvement, Colores Ceramicos chose to optimise the performance of a bag filter in a spray dryer process.

The very fine enamel powder dust produced at the spray dryer was able to penetrate the filter media, clogging the fabric, and causing high pressure drop across the filter.

This was leading to reduced production rates and a useful bag life of less than four months.

Donaldson Membranes were asked to inspect the filter, which contains 176 bags, with a filtration area of 180m2, manufactured from conventional glazed surface Polyester Needlefelt.

The cleaning system is by on/line pulse jet, dust loading is 60g/m3 and air/cloth ratio is 0.83m/min.

The operating temperature is 120-130C with a peak of 133C.

The Donaldson Membranes Sales Manager for Iberia, Jordi Ezquerro, proposed to replace the previously installed bags with filter bags manufactured from Donaldson Membranes Product code # 6214, Polyester Needlefelt with Tetratex ePTFE membrane surface.

The filter bags, manufactured by Spanish bag maker, ACMA, are still working to desired performance levels after more than 24 months in operation, an excellent improvement of bag life compared with the life of the previous bags.

Pressure drop is maintained below 150mm water gauge, with emission levels well below the required 20mg/Nm3.

Mr Ezquerro said: "We were confident that our media would solve the problem of bag fabric clogging and would extend the useful life of the filter bags - and Tetratex # 6214 has proved to be a successful solution to the problems".

Mr Angel Badenas, Production Manager at Colores Ceramicos, is pleased with the results and has commented: "We are extremely satisfied with the performance of the #6214 filter bags: the results after more than 24 months have completely fulfilled expectations from both a lifetime and performance point of view".