TRANSACTIONS OP SECTION G. 643 



4. The Manchester Corporation Gas UndertaMng. 

 By J. G. Newbigging, M.Inst.C.E., Chief Engineer.^ 



In this paper the author dealt briefly with the early history of the under- 

 taking, and quoted figures from the accounts lor the financial year ended 

 March 1915, showing how it had grown since the year 1843, when the gas works 

 became municipal property. The strong financial position of the undertaking 

 was due to the Gas Committee continually availing themselves of up-to-date 

 methods of manufacturing gas. 



•A brief reference was made to the important features of the works, more 

 particularly recent improvements. In the first and most important process of 

 gas making — carbonisation — the undertaking .has occupied a foremost place in 

 the gas industry. Manchester was one of the first to adopt mechanical stoking 

 for charging and discharging retorts, and also constructed one of the earliest 

 installations of inclined retorts, where the charging and discharging of the retorts 

 is effected by the natural gravitation of the material. The undertaking has also 

 been a pioneer in the latest and most scientific method of carbonising in vertical 

 retorts. In this system the coal passes continuously through the retorts at a 

 speed of from two to four tons per diem. The coke leaves the bottom of the 

 retort in a comparatively cool state, the heat having been extracted by means 

 of cold air circulating round the base of the retort. The advantages of this 

 system as compared with the intermittent are : saving in labour, minimising loss 

 of gas and other valuable products, and the obtaining of yields of gas of 

 13,000 to 14,000 cubic feet per ton, with a minimum percentage of inert gases 

 in its composition. 



At the Bradford Road Works a gas-holder of ten million cubic feet capacity 

 has been constructed, and is one of the largest structures of its kind in the world. 



Gas works have been bi'ought into prominence through the War because coal- 

 gas and its by-products contain substances which are either the basis of valuable 

 explosives or are xised in their manufacture. Manchester is doing its share in 

 producing these important munitions of war. 



The sulphur and ammonia produced in the process of purifying the gas are 

 converted into sulphuric acid and sulphate of ammonia, the yearly production 

 being 3,700 tons of pure acid and 5,000 tons of sulphate per annum. 



The author pointed out that, great as the success of gas enterprise had been 

 in Manchester, it would not be maintained unless the Department was allowed 

 to sell gas at cost price, and relieved from the burden of contributing large 

 sums annually in relief of rates. The author contended that the competition 

 with electricity would not permit of this extra taxation of the gas consumers. 

 He quoted .statistics showing that in Manchester electricity and gas have their 

 separate and distinct spheres of usefulness, electricity showing a steady increase 

 for power and lighting, and gas for cooking and heating. In the case of a 

 municipality controlling both the gas and electricity supplies he saw no 

 reason why the former department should not eventually become the gaseous 

 fuel supplier and the latter the light supplier. Gas of a calorific value of 250 to 

 300 B.Th.U. per cubic foot could be very cheaply produced, and this quality 

 could also be used for lighting under high pressure. 



In conclusion he pointed out that the gas industry had a better opportunity 

 than any other industry of solving the fuel question, and with it the smoke 

 problem, which are of "such importance to the nation, and so placing itself in 

 a stronger position than it now holds. 



5. A Unit Gas-Producer for Steam Boilers. By E. C. Mills. 



Gas-fired boilers may be classified roughly thus : — 



1. The gas a by-product from plant installed primarily for other purposes. 



2. Grouped producers from which the unpurified gas is piped to boilers. 



3. Grouped producers with partial or complete purification. 



4. Coal-fired furnaces placed externally to the boiler. 



5. Unit bituminous gas-producers delivering gases hot and unpurified 



direct to boiler. 



' .See Journal of Gas Lighting, September 14, 1915. 



