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).
The method of pressurizing the water cooling system and its effect on efficiency, mentioning the R-R Silver Ghost.
| Identifier | ExFiles\Box 178\1\ img038 | |
| Date | 15th February 1926 guessed | |
| - 22 - atmospheric temperature was 25°C, by raising the boiling point from 100°C to 110°C, this critical atmospheric temperature would be increased to 35°C, or from quite a normal atmospheric temperature to one very rarely encountered. The method of generating the pressure in the water system is very simple. The normal steam pipes are eliminated and the system made air-tight and fitted with a relief valve communicating with the atmosphere set to open at the required pressure, 2, 4 or 6 lbs/sq.in. as the case may be. When the temperature of the water in the radiator reaches 100°C, it tries to boil, and a certain amount of steam is generated. This cannot escape and so the pressure in the radiator rises and the water stops boiling. It will be noted that during this temporary ebullition neither steam or water is lost. When the pressure in the system reaches that at which the relief valve is designed to operate, steam escapes and normal boiling as at present understood, takes place. (ii) Maximum gain in efficiency. The normal radiator is not built to withstand high pressures In addition water joints and pump glands are liable to fail. It is hardly politic therefore to use a pressure above 6 lbs/sq.in. which raises the boiling point 10°C. In the case of the R-R Silver Ghost car in its standard condition, this is equivalent to raising the efficiency of the cooling system 13%, or rather more than is occasioned by opening the shutters and increasing the matrix height 1". contd. | ||