202 PROCEEDINGS COTTESWOLD CLUB 1914 



Gloucester included, the contention being that when the people saw a time 

 of retribution approaching, then it was that engineers were set to work to 

 defend the cities. [W.T.] 



Entering the motor cars the Members drove to the Wood-distillation 

 Works near Speech House Road Station. 



These works, erected in 1912 and 1913 from plans by Mr E. Maples Linton, 

 of Newport, instructed by Mr F. H. Meyer, of Hannover Hainholz, consist 

 of a retort of large capacity for the carbonisation of the wood, and the neces- 

 sary plant for producing and working up charcoal, grey acetate of lime, mis- 

 cible naphtha, and wood tar. 



The Cord wood used is brought in from the Crown Forest, in the centre 

 of which the Works are situated, by hauliers, and is stored in large stacks. 

 A stock of 1,500 to 2,000 cords^ is kept. 



The retort is built of iron plates, and is about 56 feet in length and yi 

 feet in diameter. It is fired from a fireplace on the left side, and is set in 

 flues, which effectually enable the wood to be carbonised. The wood is 

 stacked into cylindrical shaped trucks, each holding about 2 cords or 256 

 cubic feet, and 5 trucks form one charge for the retort. When ready the iron 

 door of the retort is lifted, and the trucks of wood are drawn in by an electric 

 motor. The door is then securely closed and heat is applied from 330 to 350 

 degrees Centigrade. Distillation usually commences in about two hours and 

 continues for from 20 to 22 hours. 



After the process is completed the door at the other end of the retort is 

 raised, and the trucks, which now contain charcoal, are quickly drawn by the 

 motor into an iron cooling chamber, and, the doors at each end being made 

 secure, it is irrigated by water to expedite cooling. From here the trucks 

 of charcoal are, on the following day, removed to the charcoal shed, where 

 they are emptied and the charcoal put into bags ready for dispatch. 



During the process of distillation about 70 per cent, of the weight of the 

 wood is given off as vapours or gases, these pass out of the top of the retort 

 through two copper pipes into a tar separator, where the tar in them is con- 

 densed and flows into a tank. It is then run into a Monte jus and lifted by 

 the compressor into the tar still, where it is freed from the acid, oils and 

 water remaining in it. It is run direct from the still into casks, and is now 

 ready to dispatch. 



The gases and vapours, freed from tar, pass out of the top of the separator, 

 and into a tubular condenser : here the naphtha and acid vapors are condensed 

 and run into large storage-vats. The " pyroligneous liquor," as it is called, 

 is left in the vats 3 or 4 days to free it from any tar that remains suspended 

 in it, and is then ready for further treatment. 



The incondensible gases leave the condenser cooled, and pass into a 

 gas-washer, into which a small quantity of water is trickling, where they are 

 freed from any naphtha or acid which may be left in them, and are then 

 conveyed by a pipe to the furnace, where they are utilised in the process of 

 carbonisation. 



The " pyroligneous liquor," freed from tar, is pumped from the storage- 

 tanks across the yard to the vat in the acid-room, where it is mixed with lime, 

 which has been prepared in the lime-mixing tank outside until all the acid is 

 neutralized. It is stirred continuously by the mechanical stirrer, until the 

 mixing and neutralization is complete. From thence it is pumped into 

 " settling-tanks " at the top of the building, then into the " sludge-tanks " 

 on the first floor, and thence into the " storage-tanks " in the acid room — 

 further impurities being removed in the sludge tanks. 



It is now pumped into the small " clear-liquor tank " on the top-floor, 

 and from thence it runs into the iron column of the " continuous apparatus." 



This consists of a wrought-iron base or still, containing a copper coil, 

 surmounted by a series of cast-iron plates, which have the effect of completely 

 separating the neutralized acid liquor from the naphtha, the neutralized liquor 

 I One "cord " = n8 cubic feet 



