June 1, 1864] THE TECHNOLOGIST. 



527 



PRODUCTS OF DISTILLATION OF COAL. 



At the meeting of the Institution of Civil Engineers, May 10, a 

 paper was read " On the Means of Utilizing the Products of the Distil- 

 lation of Coal, so as to reduce the Price of Coke ; with Descriptions of 

 the Ovens and of the best Processes in Use in Great Britain and on the 

 Continent in the Manufacture of Coke," by M. Pernolet (of Paris). 



The author believed that this question had been practically solved, 

 by the employment of existing ovens, to which certain inexpensive 

 additions were made, and which, while still giving to the coke all the 

 solidity, density, and lustre that distinguished good coke made in the 

 ordinary way, enabled every product of the distillation of coal to be 

 turned to account. This was effected, mainly, by keeping the coal from 

 all contact with the air during its distillation, by performing that 

 process very slowly, and by collecting and making use of the volatile 

 products. The whole arrangement had been sanctioned by many years' 

 experience, both in Belgium and France, where it was actively and pro- 

 fitably pursued at ten "different establishments, with more than 400 

 ovens, of the largest dimensions, capable of receiving from five to seven 

 tons of coals at each charge. 



In converting an old oven into one of the improved form, the floor 

 was taken up and raised about a foot, so as to allow of its being heated 

 from below, by means of a fire-grate and flues. A new opening was made 

 in the roof, in which was fixed a pipe intended to receive the volatile 

 products, and to conduct them to their destination. The ordinary door 

 and the other opening at the top were so arranged that they could be 

 kept hermetically closed. A chimney was also added to the masonry 

 of the old ovens, and this was an essential part of the system, as it 

 secured the circulation of the products of distillation. It had been 

 ascertained that this chimney should be 50 feet high, and not less than 

 3^ feet square, inside dimensions, for a group of sixteen contiguous 

 ovens ; and that the sectionalarea of the main flue, connecting the dif- 

 ferent ovens with the chimney, should be three-fourths that of the 

 chimney. In order to try whether the distillation was finished in any 

 one oven, a valve was closed in che outlet pipe ; when, if the charring 

 was incomplete, the gas still given off would cause cracks in the loam, 

 with which the joints of the door were closely luted, and thus the neces- 

 sity for continuing the process was demonstrated. The valve was then 

 simply reopened, so as to allow the gas again to pass off by the pipe. 

 If, on the other hand, when the valve was closed, no gas escaped at the 

 joints, the charring was known to be finished, and the coke was fit to be 

 drawn. During this operation the valve was closed, to prevent the 

 mixture of the external air with the gases circulating in the outlet pipe, 

 and the cast-iron cover of the opening at the top was kept shut, to avoid 

 the risk of igniting the coke by the draught of air which would be 

 created if it was open. The oven was arranged for charging from the 

 top, by means of waggons running upon rails, and in this way five tons 



