BAIRD &TATLOCK (LONDON) LTD. 



Electric Furnace. 



of coal. 



Fig 4. Complete Set of Research Apparatus. 

 5647-5656 



By Dr. R. Lessing. For the determination of the coking properties 



This furnace has been designed by Dr. R. Lessing to compare the Coking properties of Coal and to study 

 carbonisation phenomena, using as a standard quantity one gramme of coal ; it consists of a silica furnace with 

 the outer tube wound with a coil of thin platinum wire, and fitted with an inner tube of siliea or platinum into 

 which the sample is placed ; a further tube is used as a weight to prevent the coal being blown out of the tube. 



The swelling properties of coal are very clearly shown by this method and it is found that coals differ very 

 widely in the extent to which they expand during various periods of the test and after complete coking. 



The coke specimens, as will be seen from Fig. 2, vary in size and structure. Fig. 3 will show the constancy 

 of shape and character of a coke obtained from each coal, and if the results are compared with those of the old 

 crucible method, they will be found to be very striking. 



5647 T Electric Furnace, with resistance fitted to base for cutting down the current and for regu- 

 lating the temperature, arranged for 220 volts direct current . . . . . . 660 



5648 r Electric Furnace, with resistance, etc., but arranged for no volts direct current . . 600 



At the same time it is quite simple to extend the process to observe the quantity, etc., of the tarry vapours 

 (gases evolved during various periods of each test) by closing the retort tube and connecting to a gas collecting 

 system, as shown in illustration No. 4. 



The ammeter and millivoltmeter being simply used in standardising, the instruments are not as a rule required. 



For carrying out experiments in connecting the tar products the following extras may be required : 



5649 T Retort Tube, with addition as shown in illustration, made in silica, with glass gauge tube 076 



5650 r Tar Scrubber and Purifier . . . . . . . . . . . . ..016 



5651 T Gas Measuring Tube (nitrometer) and Aspirator with I.R. tubing . . . . . . 0136 



5652 T Millivoltmeter, 0-120 . . . . . . . . . . . . . . ..4100 



5653 T Ammeter, 0-5 in ^th . . . . . . . . . . . . . . . . 1 12 6 



5654 T Kipp Apparatus, 4 in. . . . . . . . . . . . . ..096 



5655 T Wash Bottle, 16 oz. . . . . . . . . . . . . . . ..026 



5656* Stand with Clamps, etc. . . . . . . . . . . . . . . . . 12 6 



For detailed description of procedure, see Journ. Soc. Chem, Ind., 1912, vol. xxxi., p. 465 ; and 

 Journ. o/ Gas Lighting, 1912, vol. cxviii., p. 855. 



1021 



