Page 127 - QRedition5.0 062021

Quality Requirements Edition 5.0 European Enamel Association

8.7.7 Valuation of black specks in the enamelling 8.7.8 Packing enamelled plates in baskets for regenerative heat exchangers

Definition and cause The way of packing in the baskets should be that the “notches” of the corrugated and
On light coloured direct-on enamellings (white or coloured) black specks can appear. In undulated plates always must be crossed.
these cases reacting gases convey, during firing, the adhesive layer respectively a trans-

parent layer (being rich in FeTiO ) towards the surface. By conventional enamellings the The tuning of the pressing force for packing shall be done on the required pressing force
3
ground coat layer then reaches the surface of the cover coat. as written down in the specifications for the heat exchangers.

The calculation of the pressure on the filled basket is: P = F / A
2
P = pressure in kg/m
F = pressing force in kg
2
A = pressed area in m

The calculation of A = (the one side surface area in m of the lower plate in the basket
2
+ the surface of the upper one) / 2.

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EEA2020