From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Letter reporting on the testing of petrol filters, suggesting improvements to the filtering element's capacity and plate gaps.
| Identifier | ExFiles\Box 44\1\ Scan274 | |
| Date | 24th January 1929 | |
| x4037 HS{Lord Ernest Hives - Chair}/Rml/T. 24th January, 1929. Messrs. Benton & Stone, Bracebridge Street, BIRMINGHAM. For the attention of E.{Mr Elliott - Chief Engineer} Milner, Esq. Dear Sirs, Petrol Filters. -------------- We have now carried out some very considerable testing on the three filters you supplied to us, and while on the whole we are very satisfied with them, we think that there are one or two improvements which can be made in the filtering element. Our first trouble with the Duralumin element has been lack of capacity. Actually the superficial area of the plate cylinder is 67% greater than that of the Zenith, but owing to the thickness of the Duralumin plates there are actually only 65 plates in your filter as against 69 plates in the Zenith filter. We are therefore getting only the benefit of the increased dia., 16%. This benefit is lost owing to the fact that the average width of the gap between consecutive plates is .0024" on the Zenith against .0014" on the Enots. Upon examining the plates under the microscope we find very considerable variations in the width of the gaps. Taking 10 plates, we have - Average width of gap .0014" Width of largest gap .0022" Width of smallest gap .0008" additionally the edges of a number of the plates were burred, further reducing the gaps in places. (1) Contd. | ||