LIQUID FUEL 399 



space excavated by it on the bog. This digger raises -the material into a disintegrator of 

 special design, whence it is pumped through pipe lines to the works. 



The power required at the peat getting station is supplied by generating electric current 

 in the works and transmitting it to the. plant at the bog. The peat pulp is then passed 

 through the carboniser, which may consist of an arrangement of two concentric tubes, such 

 as is found in the Nichlausse boiler, heated in a gas furnace. The raw peat is pumped 

 continuously into the space between the outer and inner tube, and the carbonised peat, 

 flowing back in the reverse direction through the inner tube, thus parts with its heat to the 

 entering raw pulp. Under the pressure existing in the carbonising plant the pulp passes 

 into the filter presses, which squeeze out much of the water, leaving the peat in a condition 

 ready to go into the producer for ammonia recovery, or, after further drying by the waste 

 heat of the gases from the producer, to the briquetting press. 



One of the chief points in the process is that double the quantity of peat is treated that 

 is required as briquettes, one half being taken as press cake, and used in producers of the 

 Crossley type for conversion into producer gas, which, after the ammonia in the gas has been 

 absorbed by sulphuric acid, is then partly employed in a battery of gas engines to give the 

 necessary power for working all the apparatus used and bringing the peat from the bog, and 

 also for supplying the heat for drying the remaining half of the peat that is to be briquetted, 

 down to about 5 per cent of moisture. 



Peat contains nitrogen in amounts which vary from I to 3 per cent, and theoretically for 

 every one per cent of nitrogen present it should be possible to obtain 105 Ibs. of ammonium 

 sulphate per ton, but in practice with gas producers of the Crossley type about 75 to 80 

 per cent of this quantity is recovered. 



The calorific value of the peat blocks made in the briquetting press is about 5,490 calories 

 or 9,882 B Th U, and as the amounts which can be carbonised for ammonia recovery or can 

 be briquetted are very elastic, the output can be arranged to meet local requirements. This 

 process is undoubtedly far more promising than any that have been before attempted. 



2. Liquid Fuel. 



During 1911 and 1912 the use of liquid fuel has again received an impetus from the 

 successful results obtained with it in practically all the naval services in the world. The 

 American Government are safeguarding the supply for naval purposes by taking con- 

 trol over an area of the Californian oil fields, which will be held in reserve. In Great 

 Britain the shortage of fuel oil supply, due largely to difficulties in transport, will prob- 

 ably disappear when the large number of new tank vessels now building are completed, 

 and these will allow of the utilisation of the large supplies of fuel oil which will be avail- 

 able from Mexico, the Dutch East Indies and Burma, as well as from Texas and Cali- 

 fornia. The price of liquid fuel limits its use to a great extent, as it is only where the 

 advantages to be gained by its employment are so great as to overshadow the question 

 of cost that it can possibly compete in Great Britain with coal, and the factor which pre- 

 vents its adoption in very many directions is the impossibility of getting any guarantee 

 as to constant supply. Freights have recently been so high as to make the price of the 

 oil in England almost prohibitive, and the question is whether the carriage can be so 

 reduced as to bring the price down. The great hope of the fuel oil market at the end of 

 1912 rested in the enormous demand for petrol, which during the next few years promises 

 to lead to the development of all possible sources of oil; after the portion possible to use 

 for motor-car fuels has been distilled off, the residuum, which is the portion of the oil 

 available for fuel purposes, will be correspondingly large; but it must be remembered 

 that in most of the countries on which Great Britain relies for oil supply the use of liquid 

 fuel is advancing rapidly. In America, Russia, Austria and other countries producing 

 oil or close to the oil fields, liquid fuel is now replacing solid fuels in the locomotives on 

 the Government lines, as well as for manufacturing and other purposes, so th^t the sup- 

 ply from these sources for export is only what is left over after the home consumption 

 has been satisfied. This of course does not apply to the Indian and Mexican fields, 

 from which large supplies of fuel will probably be available. 



Oil Fuel Burners. Most of the earlier burners used for the consumption of oil in place 

 ot' coal in marine boilers rely on the principle of injecting the oil as a fine spray into the 

 furnace by means of steam, air or pressure. These burners answered well when the combus- 

 tion space was large, but where a considerable amount of oil had to be burnt in a small space 

 their action of driving forward the oil supplied rendered the passage of the burning oi! 

 through the combustion space too rapid to allow of complete combustion, and large quantities 



