BRITISH CHEMICAL ABSTRACTS
B.—APPLIED CHEMISTRY
O C T . 24 and 31, 1930.*
L -G E N E R A L ; PLANT; MACHINERY.
Grinding capacity of flint-ball m ills. A. H. M.
An d r e a se n and J. J. V. Lu n d b er g (Trans. Ceram. Soc., 1930, 2 9 , 239—250).-—Calcined Danish ball-flint was wet-ground in a flint-ball mill, and during a period of grinding the variation of fineness was determined by the pipette method. During the test nine samples were taken and data showing hours of grinding, current used, revolutions per minute, total number of revolu
tions, grain sizes, and increase of surface are tabulated.
R ittingcr’s law, th a t the increase in surface is directly proportional to the energy consumed, does not apply for the system under test. R. J. Ca r t l id g e.
Cascading v. cataracting in tube m ill. H. A.
Wh it e (J. Chem. Met. Soc. S. Africa, 1930,31,1—IS).—
The theory of the use of balls for grinding in tube mills is discussed and formula} for the optimum speed of rotation and power required are given. Experiments bearing on the theory have been carried out and the effect of moisture was investigated. D. K. Moore.
Fluids handling. I. W. L. B a d g e r an d E . M.
B a k e r (C hem . M et. E n g ., 1930, 3 7 , 370—373).
II, III. W. L . B a d g e r a n d W. L . M cC abe {Ibid., 430—434, 494—499).—A d e sc r ip tio n is g iv e n o f th e v a rio u s m eth o d s o f jo in tin g iron a n d s te e l p ip e s a n d of ty p e s o f v a lv e s . A ir lifts , ejecto rs, and recip rocatin g pu m p s are d e a lt w ith , fo llo w ed b y v a r ie tie s o f rotary an d c e n trifu g a l pum ps, com pressors, an d blow ers, all b ein g tr e a te d from th e en g in eerin g p o in t o f v ie w .
C. Ir w in. D eterm ination of m acro-pore volum e of porous substances. St a d n ik o v. Absorption pipette for gas a n a ly sis. Ot t.—See II.
See also A., Sept., 1102, Intensive drying of liquids (Sm its). 1115. M easurem ent of particle size in u ltra-violet lig h t (Haslam and Hall).
Pa t e n t s.
O pen-hearth furnace. W. Ga st (U.S.P. 1,756,484, 29.4.30. Appl., 23.6.21).—The air ports of the furnace are situated immediately over the regenerators and each is tapered, forming a throat which is more or less ob
structed by a sliding gas nozzle. Preferably the adjustment of the gas nozzle simultaneously adjusts the gas supply. B. M. Ve n a b l e s.
H eat-interchanging apparatus. Serck Ra d ia
tors, Lt d., and C. O. Wa g n e r (B.P. 333,764, 5.9.29).—
An exchanger suitable for heating air, or cooling liquids by means of air, comprises a number of gilled tubes between inclined plates ; the upward ends of the latter open into a common uptake or chimney producing a natural draught. B. M. Ve n a b l e s.
H eating in a gaseou s atm osp h ere, particularly in a reducing or oxidisin g atm osphere. H. Sch a e fer
(B .P . 333,192, 1.2.29).—The articles are heated by the sensible heat only of a gas, before combustion, which has been highly heated in a reversible regenerator. After passing through the goods the gas is mixed with air and burned in the other side of the regenerator. For an oxidising atmosphere the air would be heated.
B. M. Ve n a b l e s. Cooling or heating apparatus particularly applic
able to viscou s flu id s. R. Seligm an (B.P. 333,157, 28.3.29).—The apparatus comprises an inclined rotating cylinder cooled by exterior water sprays. Scrapers or
“ doctors ” are provided on the interior to control the thickness of the layer of material, but these scrapers extend through only p art of the length, the remaining part a t the outlet end being occupied by shelves or scoops to discharge the material.
B . M. Ve n a b l e s. Apparatus for d rying, heating, and evaporating.
W . Hobson (B .P . 332,951, 27.2.29).—Material such as clay is run or pressed into tubular containers while in a fluid state. The tubes are impervious or pervious according to whether steam or a drying gas is used for heating. Apparatus of both kinds may be combined with a heat exchanger, so th a t live or exhaust steam may be used in one and the vapour produced may give up its heat to gases in the exchanger and the gases dry another batch of clay contained in pervious tubes.
B. M. Ve n a b l e s. D rying dru m s. A. Ca r p m a e l. From Bu t t n e r- We r k e A.-6. (B .P . 333,517,8.5.29).—A drying drum of large size is sectionalised so th a t the parts will come within the limits of railway loading gauge.
B. M. Ve n a b l e s. Separating arrangem ent for pneum atic centri
fugal d ryers. E. Ba r tiielm ess (B .P . 333,859, 22.1.30.
Ger., 7.2.29).—After leaving the dryer, the air-borne material is caused to pass downwards and then upwards through a conduit with a return bend of small radius, a t the bottom of which are a port and sack or other con
tainer to collect heavy or large particles.
B . M. Ve n a b l e s. Grinding m ills. H . Dr y sd a l e (B .P . 333,404, 21.2.29).—A mill of the type described, having a convex surface rotating about a (usually) vertical axis and engaging with a smaller concave surface rotatable about an inclined axis, is provided with positive drive to both elements, the relative speed being variable the pressure between the elements can be varied, one element can be swung aside, and temperature control (water-cooling) can be applied through the hollow axis of one or both
elements. B . M. Ve n a b l e s.
a p p e a r in n e x t w eek’s issu e .
* T he re m a in d e r of th is se t of A b s tra c ts w ill 969
B r itis h C h e m ic a l A b s tr a c ts —B .
0 7 0 Cl. I . — Ge n e r a l ; Pl a n t ; Ma c h in e r y.
G rinding m ills . E. F. Stim son (B.P. 333,635, 28.2.30).—In a mill of the type described in B.P. 333,404 (preceding abstract) both elements are positively driv en ; of the upper member only the rim is pressed by springs towards the lower member, and a definite minimum clearance is maintained. Liquid seals are provided to prevent lubricant from the upper member reaching the grinding surfaces and to prevent dirt reaching the driving mechanism of the lower member.
B. M. Ve n a b l e s. Grinding m ills . Macao-Wal ze n m u u l e n-Ge s.m.b.H . (B.P. 313,611, 14.6.29. Ger„ 15.6.28. Addn. to B.P.
291,803 ; B., 1928, 878).—A mill acting on the principle described in the prior p aten t comprises the following parts in order downwards, the rotating parts being driven by a vertical s h a f t (1) agitator-feeder ; (2) single- faced annular disc, non-rotating bu t adjustable axially ; (3) set of double-faced planetary discs, the gear wheels being between the faces, and the sun pinion on the shaft serving also as a collar so th a t the planets may be adjusted axially by raising the s h a f t; (4) double-faced annular disc, non-rotating (or oppositely rotating) but having a limited axial freedom ; (5) set of planets as in (3) ; (6) double-faced annular disc, sta tio n a ry ; (7) rotating annular disc having limited axial freedom on the s h a f t; (8) footstep for shaft adjustable in height.
The construction is such th a t all wearing parts may be made of porcelain and the annular discs are preferably
grooved. B. M. Ve n a b l e s.
G rinding m ills. Babcock & Wil c o x, Lt d. From Babcock & Wilc ox Co. (B .P . 334,058, 22.8.29).—The mill is in the form of a vertical, double-thrust ball
bearing of which the middle race is driven by power ; the feed is to the outside of the upper ring of balls, and the ground material is borne away by upward internal air currents and passes through classifiers which return coarse material to the grinding zones.
B. M. Ve n a b l e s. G rinding and subdividing apparatus. J. E.
Ge r n e l l e-Danloy(B.P. 311,329, 3.5.29. Fr., 9.5.28).—
A number of superposed discs are rotated by a vertical shaft, and grinding is effected by horizontal rollers on their upper faces. The material flows over the edge and through a central aperture of alternate discs which are coned and the rollers provided with spiral grooves to assist the flow . B. M. Ve n a b l e s.
M ethod and m ech anism for grinding and separat
ing m aterials. W. J. Clem ent, Assr. to Bossert
Co r p. (IJ.S.P. 1,755,573, 22.4.30. Appl., 7.4.28).—
A disintegrator of the hammer type is provided with an outward bulge on the circumference of the casing.
Pa,rtly filling the bulge is a hollow element of which the concave face forms a continuation of the normal curve of the casing, but the outer convex face is formed of screening (or even left entirely open) so th a t fine material can be withdrawn through it by means of an air current.
B. M. Ve n a b l e s. [Disc] m ills for grinding p ain ts, en am els, in k s, and other viscou s su bstan ces. Disc B a r Mil l s, Lt d., and E. A. Wh it e (B.P. 333,436, 30.9.29).—The fixed element comprises a hollow member of wavy, cruciform, or star shape of which the leading grinding
edges are smooth and the trailing edges are grooved across their thickness. The rotating disc is horizontal.
B . M. Ve n a b l e s. D evice for reducing [the size of] m aterials.
H. G. Ly k k e n (U.S.P. 1,756,253, 29.4.30. Appl., 9.12.25).—The apparatus comprises rotors on a vertical shaft within a vertical casing, the material being adm itted a t a point above the bottom and air in con
trollable quantity through the bottom. The lower rotors produce an eddying motion which effects the reduction, passage of the air-borne material straight upwards is prevented by baffle plates, there is a compara
tively quiet zone above the eddying rotors, a n d the material is drawn out through the top by a fail on the same shaft. The wall of the casing may be provided with deep grooves to retain a substantial layer of solid material, and with a side pocket to catch uncrushable
material. B. M. Ve n a b l e s.
M achines for crushing coal, stone, and sim ilar m aterials. H. Ma r tin ez a n d R . H . Kir k (B.P, 333,642, 21.5. a n d 20.11.29).—A crusher of th e sw in g - ja w or o th er ty p e is o p era ted th ro u g h r e silie n t m em b ers so th a t th e cru sh in g m em b er ca n y ie ld to u n cru sh ab le p ieces a t b o th th e in le t a n d o u tle t e n d s, p refera b ly in su ch a w a y th a t th e cru sh in g m o tio n ch a n g es to slid in g or ru b b in g . B. M. Ve n a b l e s.
P u lverising m ills. In t e r n a t. Com bustion En g. Co r p., Assees. of II. Kr e isin g e r (B.P. 317,081, 1.8.29.
U.S., 11.8.28).—In a grinding system for coal etc., in which a substantial part of the air travels in a closed circuit, heated air or gas for drying purposes is adm itted to the grinding mill in such a way th a t it will not come in contact with stationary accumulations of coal which inevitably collect about the lower p art of the g rin d e r;
to this end the heated gas is adm itted as an upper stratum to the main stream of returning air immediately before it enters the mill. B. M. Ve n a b l e s.
M ixing, d issolvin g , or sim ila r apparatus. H. S.
Be e r s, Assr. to Turbo-Mix e r Co r p. (U.S.P. 1,756,236, 29.4.30. Appl., 29.5.29).—A tan k is provided with an impellor near its suitably curved bottom and with a set of parallel spaced plates having teeth formed on them by which fibrous or viscous material is broken down.
B. M. Ve n a b l e s. T roughs and the like for kneading, m ix in g , etc.
Ba k e r Pe r k in s, Lt d., and R. H. We b b (B .P . 333,993, 18.6.29).—The inner lining of a jacketed vessel is formed without rivet holes or joints, recesses are formed on the back of the lining, and pads forming distance pieces for the jacket space are ball-paned into the recesses. A somewhat similar method is used for attaching the stuffing boxes for the stirrer shaft. The apparatus is particu
larly applicable for mixing cellulose acetate.
B . M. Ve n a b l e s. H om ogen ising m ill. W. Epp e n b a c h, Assr. to Un it e d Sta te s Colloid Mill Co r p. (U .S .P . 1,755,576, 22.4.30. Appl., 23.7.27).—A form of mill having flat annular working surfaces and bottom discharge is
described. B. M. Ve n a b l e s.
H eating of decom posable liqu ids. J. Y. Johnson. From I. G. Fa r b e n in d. A.-G. (B.P. 333,241, 8.2.29).—
In an apparatus for heating liquids th a t deposit carbon
Cl, I.— Ge n e r a l ; Pl a n t ; Ma c h i n e r y.
B r itis h C h e m ic a l A b s tr a c ts — 3 .
971
or other scale, of the type in which the heating means is kept in motion, such means are shaped so as to produce as little stirring action as possible, e.g., they may be in the form of strips, electrically or otherwise heated, with their length parallel to the axis of rotation and with a cross-section in streamline form with the axis of symmetry tangential to the circle of rotation.
B . M. Ve n a b l e s. Line filter. 0. 6 . Ha w l e y, Assr. to Ce n t r if ix
Co r p. (U.S.P. 1,755,780, 22.4.30. Appl., 8.3.26).—
A stationary device, suitable for insertion in a pipe-line, which embodies no true filtering or straining action, bu t depends on inertia and gravity, is described. The liquid to be purified {e.g., water) is impelled towards three substantially motionless bodies of the fluid in succession, the purified liquid being withdrawn sideways from the stream. The first action is in a straight line downwards to separate the larger heavy impurities, the second is in a spiral path downwards to separate the remaining heavy particles, and the third straight up
wards to separate light particles, gases, etc.
B . M. Ve n a b l e s.
A pparatus for straining liqu ids. F. Ba il e y and F. H. Jac kson (B .P . 333,850,11.12.29. Holl., 5.1.29).—
A strainer for large quantities of liquid, e.g., circulating water, has a fixed vertical screen divided into sectors which is cleaned sector by sector by means of a back flush of strained water applied through a rotating flush box on one side and exhausted through a corre
sponding waste box on the other side. Automatic means are provided so th a t the flush water is only applied for short intervals when the flush and waste boxes coincide exactly with a sector of the screen.
The screen may be on the suction side of the circulating pump and the flush water taken from the delivery of the same pump. B . M. Ve n a b l e s.
Straining or filtering apparatus. Auto-Klean
St r a in e r s, Lt d., and W. B. Belda m (B .P . 334,029, 27.7.29).—A form of construction of an edge strainer formed of thin discs spaced apart by distance pieces is described. The discs are annular and are threaded on and rotated by a cage of rods passing through internal lugs ; fixed scrapers also of thin sheet extend into each filtering space. B . M. Ve n a b l e s.
D istillation of liquids [especially crude g ly cerin ].
W. E. Sa n g e r, Assr. to O. H. Wu r st e r (U .S .P . 1,743,488, 14.1.30. Appl., 27.4.25).—Glycerin is distilled in an apparatus such as th a t described in U.S.P. 1,743,289 (B., 1930, 492), preferably making use of a vacuum.
B. M. Ve n a b l e s.
R eleasing the pressure of m ixtu res of solids and liquids existin g under high pressure. C. F. R.
Harrison, S. Labro w, and Im per ia l Chem. In d u s t r ie s, Lt d. (B.P. 333,210, 4.5.29).—The condition necessary to avoid abrasion of let-down devices is found to be that at least p art of the potential energy of the fluid must be converted into work without development of any considerable kinetic energy. The material is therefore exhausted through a pump used as a motor. Pumps
°f the screw-viscosity, drum, gear, or ram types may be used. " B. M. Ve n a b l e s.
Fractional d istillatio n . W. F . St r o u d, JUN., an d
R . B. Ch il l a s, j u n., Assrs. to Atl a n t ic Re f in in g Co. (U.S.P. 1,744,421, 21.1.30. Appl., 17.12.28).—To re
duce the volumes of the vapours and the reflux liquid in the upper p art of a fractionating tower, liquid is withdrawn from one or more intermediate points, preferably a t a greater rate than the downflow, is cooled, and p a rt or all returned to a tray or trays not below th a t from which it was withdrawn. B. M. Ve n a b l e s.
A pparatus for vapour fraction ation. J. C.
Mo r r e l l, Assr. to Un iv e r s a l Oil ProductsCo. (U.S.P.
1,744,134, 21,1.30. A ppl, 16.5.27).—The upflow pas
sages in a fractionating column are in the form of pipes with closed upper ends, the upper cylindrical walls being perforated. Below the trays are diaphragms, as described in U.S.P. 1,738,386 (B., 1930, 590), with the addition of unobstructed apertures through the centre.
B. M. Ve n a b l e s.
Purification of liqu ids. St a n d a r d Oil De v e l o p
m ent Co., Assees. of F. W. Isl es (B.P. 314,016, 8.6.29.
U.S., 21.6.28).—A liquid is treated with another which is immiscible and of different density by flowing them countercurrent in a substantially horizontal conduit.
Turbulence is promoted by a number of jets of the heavier liquid inserted through the upper wall of the conduit, and the liquids are afterwards separated by settling in columns. B. M. Ve n a b l e s.
Preparation of d isp ersio n s. H. D. Elk in g to n. From N .V . d e Bata a fsc h e Petro leum Ma a t s. (B .P . 334,100, 9.10.29).—A dispersion of, e.g., 55% of asphalt in 41% of water, is prepared by the aid of 4% of dispersing agent by known means such as a mixer followed by a high-speed beater to reduce the viscosity, then, as a separate operation, further quantities of asphalt and water are added to bring the final dispersion to 61% of asphalt w ithout any further addition of dispersing agent, bu t with control of the a t one or more stages.
B. M. Ve n a b l e s.
Apparatus for m ix in g and em u lsifyin g liqu ids.
P. L. A. Th ib er g e (B.P. 312,649, 29.5.29. Fr., 29.5.28).
—The constituents are contained in separate reservoirs and delivered to the emulsifier by individual pumps of equal capacity, driven by a common shaft. The pro
portioning is effected by three-way valves which by-pass more or less of the constituents back to the reservoirs.
The emulsifier proper may be in the form of a ball bearing and the constituents enter a t different points.
B . M. Ve n a b l e s.
S p ra y in g or a to m isin g of liq u id s. K. W.
Branczik (B.P. 333,701, 8.7.29).—The liquid is passed through a conduit which is bent to form a helix of increasing radius and terminates in a spraying nozzle.
B. M. Ve n a b l e s.
Apparatus and m ethod for crystal grow th.
Im pe r ia l Ch e m. In d u s t r ie s, Lt d., and H. E . Cocksedge
B.P. 333,598, 18.4.29).—The crystallising vessel has a vertical cylindrical partition and curved bottom, forced circulation being maintained downwards in the centre and upwards in the annular compartments. Crystals are drawn off downwards through an élutriation column in which the rising current is either fresh liquor or is crystallising liquor drawn off from the upper p art of
B r itis h C h e m ic a l A b s tr a c ts —B .
972 Cl. II .—Fuel ; Gas ; Tar ; Mineral Oils.
the crystalliser through a screen and slightly reheated or diluted to destroy small crystals. B. M. Ve n a b l e s.
S alin om eters and the lik e. Ev e r sh e d & Vig n o l e s, Lt d., and C. E . Pe r r y(B.P. 333,727, 2.8.29).—A salino- meter of the type in which the electric conductance of a column of liquid is measured is provided with tem pera
ture compensation in the form of an insulating mass which, under control of a therm ostat, is more or less submerged in, and changes the cross-section of, the column of liquid. B. M. Ve n a b l e s.
A pparatus for separation of gas m ix tu re s. J . Y.
Jo hn son. From I . G. Fa r b e n in d. A.-G. (B.P. 333,907, 15.4.29).—P artial separation of the constituents of a gas is effected by diffusion into a liquid of which a large surface is exposed and is simultaneously vaporising, the evolution of the desired constituent being effected by condensing the vapour. E.g., a mixture of 72% of hydrogen and 28% of nitrogen is passed upwardly around an annular mass of Raschig rings, which are irrigated with water a t 90°, the vapour being condensed on a central cooled tube ; the gas, after passing once through the apparatus, contains 82% of hydrogen.
B. M. Ve n a b l e s. Separation of gaseou s m ixtu res b y diffusion.
I. G. Fa r b e n in d. A.-G. (B.P. 308,792, 11.3.29. Ger., 31.3.28).—A non-porous foil of a metal th a t will com
bine with or dissolve the desired constituent of the gas is supported on a suitable permeable support and sub
jected to the mixed gas on one side a t much higher pressure (preferably a t least 20 atm. in excess) than th a t on the other. E.g., a disc of palladium (10 cm.
in diam. and 0-04 mm. thick) supplied with industrial hydrogen on one side at 70 atm. pressure will yield by diffusion 900 litres of very pure hydrogen per hr.
when the temperature is 400° and the lower pressure
1 atm. B. M. Yenaisles.
Separation of gaseou s m ix tu res b y liquefaction.
L ’Air Liq u id e Soc. An o n, p u r l’Et u d e e t l’Ex p l o it,
d e s Proc. G. Cla u d e (B.P. 333,127, 29.11.29. Fr..
18.12.28. Addn. to B.P. 263,732 ; B., 1927, 320).—
In the modified process the wanted gas of low b.p.
which has been cooled and purified in the triple-flow exchanger is, before expansion, further cooled (and purified) by itself after expansion in an ordinary ex
changer. B. M. Ve n a b l e s.
T reatm ent of vapours, g ases, etc. N. G. Lin d e r-
borg (U.S.P. 1,756,693, 29.4,30. Appl., 28.4.23).—
Vapours etc., e.g., those produced during the manu
facture of lubricating oil, are withdrawn under vacuum and simultaneously condensed by a cooling medium, e.g., water, in an ejector device ; after leaving the ejector the mixture is passed through an eddying chamber and then to a separating chamber. Any vapours arising from the separating chamber may be scrubbed and absorbed in separate devices.
B. M. Ve n a b l e s. M ethod and apparatus for perform ing chem ical sy n th esis. Hirsc h Ku p f e r- u. Me s sik g w e r k e A.-G.
(B.P. 314,999, 4.7.29. Ger., 6.7.28).—Metallic or other conducting bodies are placed with the material in an autoclave and are heated and stirred by induced alter
nating currents and fields. B. M. Ve n a b l e s.
Vacuum drying apparatus. A. E . Jonsson (U.S.P.
1,775,397, 9.9.30. Appl., 1.6.28. Swed., 13.6.27).—See B.P. 292,105 ; B., 1929, 496.
Apparatus for production of disp ersion s of solids in liqu ids. W . H. Wiiatmough, Assr. to Sta n d a r d
Pboducts Co r p. (U.S.P. 1,774,910, 2.9.30. Appl., 4.10.28. U.K., 14,10.27).—See B.P. 304,178 ; B., 1929, 268.
C olorim eter. F. Twyman and J. Perry, Assrs. to A. Hil g e r, Lt d. (U.S.P. 1,775,148, 9.9.30. Appl., 30.8.29. U.K., 18.8.28).—See B.P. 324,351 ; B., 1930, 400.
Furnace roofs. J . Ch a sse u r (B.P. 333,943, 24.5.29).
H eat-exchanging devices, particularly for con
densers of refrigerating apparatus. Electro lux, Lt d. From Pla te n-Mu n t e r s Refr ig e r a t in g System
Ak t ie b. (B .P . 334,333, 19.7.29).
Refrigeration apparatus for vehicles fitted with cold-storage roo m s, m ore particularly railw ay refrigeration cars. Sil ic a Ge l Co r p., Assees. of E . B . Mil l e r (B .P . 310,336, 22.4.29. U.S., 23.4.28).
[Shaking-table] separation of dry m aterials [by m eans of upward air currents]. C. W. H . Holm es, and Bir t l e y Iron Co., Lt d. (B .P . 333,622, 17.5.29).
Spraying or atom isin g devices suitable for use as liquid fuel burners or road sp rayers. C. R . G.
Be a d l e and J . A. Ga u l d (B .P . 333,883, 20.2.29).
[Internally-lined] valves for corrosive flu id s.
P. Ju l ie n (B.P. 334,150, 27.12.29. Fr., 29.1.29).
R otary furnaces (B.P. 331,673). Combined gas and steam producer (B.P. 309,048).—See II. T reat
m en t of filtering m aterials (U.S.P. 1,742,433).—
See VII. Annealing furnaces (B.P. 333,596).—See V III. Purification of g a ses (B.P. 316,626 and 333,427).
—See XI. D istillin g w ater (B.P. 334,141).—See X X III.
II.— FU EL; G A S; T A R ; MINERAL OILS.
A sturian coal. III. E nrichm ent of a g as oil.
B . A. Bu y l l a (Anal. Fis. Quim., 1930, 2 8 , 959—966 ; cf. B ., 1930, 540).—On berginisation for 1 hr. of an oil (32% of volatile matter) a t a maximum temperature of 450° and a maximum pressure of 246 atm., a yield of 22-2% of oil and 64% of solid was obtained. The solid „residue contained 29% of volatile substances, 9-4% of primary tar, and 59-5% of hard and coherent
coke. H. F. Gil l b e.
Coal-tar pitch as a binding agent for bitum inous coal briqu ettes. A . Sp il k e r [with G. Born] (Brenn- stoff-Ckem., 1930, 1 1 , 307—318).—Previous1 work on the briquetting of coal, particularly brown coal, is reviewed. Experiments have been carried out to deter
mine the influence of size of coal and the proportion and quality of pitch on the strength of briquettes made from a bituminous coal under otherwise similar conditions.
The tensile strength and breaking strength of the briquettes were determined by the methods used in the cement industry, and the cohesion was determined by a modified trommel ” test. The briquettes were allowed to dry to constant weight before being tested.
B r itis h C h e m ic a l A b s tr a c ts — B .
Cl. H . — Fu e l ; Ga s ; Ta r ; Mi n e r a l Oi l s. 973
By varying the size of coal within the limits usual in briquetting it was possible to bring about greater varia
tions than were produced by varying the proportion of pitch by 25%. Other conditions being equal, coal of size 3—0 mm. gave the strongest briquettes. An increase in strength was produced also by using a more finely- ground pitch. The results emphasise the importance of a uniform distribution of pitch in the mixture. Softer pitches gave briquettes of higher cohesion but lower tensile strength ; with too soft a pitch, however, the trommel test failed. A. B. Ma n n in g.
Apparatus for determ ining the p lastic range of bitum inous coals. R. K a ttw in k e l (Brennstoff-Chem., 1930, 11, 329—330).—The coal, either powdered or briquetted, is heated in a small silica tube placed in the centre of a thick-walled aluminium cylinder. The tube is provided with a ground stopper and gas outlet tube. A narrow slot in the cylinder permits the sample of coal to be observed. The cylinder is heated by a gas burner, rather rapidly to 250°, and thereafter a t 5°/min.
Temperatures are taken at the following points : (a) the bitumen decomposition point, characterised by. the condensation of oil in the stopper and outlet tube ; (b) the softening point, a t which the coal begins to sw ell;
and (c) the solidification point, a t which swelling ceases.
The plastic range is the interval between (b) and (c).
After determining the solidification point the stopper is removed and the tube heated a t 520° for 10 miri.
The yield of semi-coke, given by the weight of the residue, agrees to within 1—2% with th a t given by Fischer’s aluminium assay. A number of typical results are tabulated. A. B. Ma n n i n g.
A nalytical characteristics of coals. W . Fuchs
(Brennstofl-Chem., 1930, 11, 332—334).—The chemical methods available for the characterisation of coals are grouped into four classes: (a) ultim ate analysis ; (b) proximate analysis; (c) decomposition analysis, i.e., determination of moisture, ash, bitumens, humins, humic acids,"and humates (cf. B., 1929, 5); and (d) deter
mination of definite atomic groupings, e.g., C 02H, OH, double linkings, etc. The application of these methods is briefly discussed. A. B. Ma n n in g.
L ignite. I. A n aly sis of lig n ites of varying degrees of carbonisation. I I . P roperties and com position of h u m ic acid. R. Od a (J. Soc. Chem.
Ind., Japan, 1930, 33, 302—304 b, 304—305b).—I. To follow the change of composition with carbonisation, recent, middle-aged, and old ligiiites have been analysed.
The water content increases with age, 13—17—24%, also the amount of ash, 1—8—21%, but the bitumen pre
sent remains constant at about 2%. The humic acid content rises from 5-65% (containing 3-51% OMe) in recent lignite to 34-2% (1-20% OMe) in middle-aged lignite, and decreases to 2-2% (1-53% OMe) in old lignite. Cellulose, determined (a) by treatm ent with 42% hydrochloric acid and (£>) by Schmidt’s chlorine dioxide method, gives figures (a) 19-6—9-2—2-2%, and (6) 19-5—4-4% —trace for the three lignites. The recent lignite contains neither humin nor humus carbon, but much lignite (56-9%), although K arrer’s acetyl bromide method indicates only 4 • 12% ; this showed th at the lignin is already somewhat altered. In the midcue-
aged and old lignites the amount, of humin and humus coal increases to 19 and 47-5% respectively, whilst the lignin figures determined by K arrer’s method are I - 92% and a trace.
II. The humic acid from middle-aged lignite has the following composition : C 57-53, H 4-69, OMe 1-20, carbonyl oxygen 3-25, ash 5-94% ; it shows strongly acid properties, and ou the assumption th a t it is a true acid the acidity in equivalents of evolved carbon dioxide is 18-65%. Humic acid liberates iodine from potassium iodide solution, and reduces Fehling’s solution. Méthyl
ation by treatm ent with hydrogen chloride in absolute methyl alcohol, followed by four-fold treatm ent with diazomethane, gives a methoxyl content of 12-06%, which is composed of 7 • 66% ester-methoxyl, determined by von Fellenberg’s method, and 6-60% ether-methoxyl.
From those figures it is calculated th a t humic acid contains 1-87% OH and 11-70% C 0 2H.
C. W. Sh o p p e e. B ehaviour of coal during carbonisation. I.
Change of m oistu re-ab sorbin g pow er of coal b y carbonisation. II . Change of electrical conductivity of coal during carbonisation. II I . Change of com position of coal b y carbonisation. S. Ik i (J.
Soc. Chem. Ind., Japan, 1930,33, 320—3 2 1b, 321—3 2 2b, 322— 32 3 b).—I. Samples of anthracite, bituminous coals of different caking power, and brown coals were pulverised to a definite degree of fineness (below 100- mesh), heated for 15 min. a t 100—1000°, and the resulting cokes pulverised to below 100-mesh. The power of absorbing moisture gradually decreases by heat-treatm ent, becoming minimal for a sample car
bonised, a t 400° for bituminous coal and 600—700° for brown coal; by heating at higher temperatures it increases rapidly and becomes maximal a t 700—800°
for high-caking bituminous coal, but lower-caking b it
uminous coal, anthracite, or brown coal only attain this maximum a t 1000°. The relationship between moisture- absorbing power and the tem perature of carbonisation of wood charcoal is nearly the same as th a t of coal, especially low-grade brown coal. There is a close relationship between the moisture-absorbing power of coke and the caking power of the parent coal ; the higher the caking power of the original coal, the smaller is the power of moisture absorption of the coke. The moisture-absorbing power of carbons decreases with increase of the degree of carbonisation, i.e., retort carbon
> blast-furnace coke^> gas coke> coalite^- charcoa£>
activated carbon ; in the same sample of retort carbon or blast-furnace coke the lustrous hard portion, wdrich appears to be the decomposition product of bitumen, has a smaller power of moisture absorption than the dull porous portion. The moisture-absorbing power of cokes and carbons thus forms an im portant indication of their origin, tem perature of carbonisation, and properties.
II. In continuation of previous work (B., 1929, 344), determinations of the electrical conductivity during carbonisation of the samples used above has been carried out by Sinkinson’s method (B., 1928, 734).
This value for coal increases gradually from 400°, rapidly from 700°, becoming nearly constant a t 1000°.
The change of electrical conductivity of wood by car
bonisation a t various temperatures is nearly the same as
B r itis h C h e m ic a l A b s tr a c ts — B .
974 Cl. I I . — Fu e l ; Ga s ; Ta r ; Mi n b r a l Oi l s.
for coal, especially low-grade brown coal. Coke prepared from higher-caking coal has a greater conductivity than th a t from lower-caking coal. The electrical con
ductivity of various carbons increases with the degree of carbonisation in the order co alite< gas coke<^ blast
furnace co k e < retort carbon<^ graphite ; in the same sample of retort carbon or blast-furnace coke the lustrous hard portion has greater conductivity than the dull soft portion. The degree of carbonisation of coalite, charcoal, and activated carbon is thus indicated by the electrical conductivity.
III. Changes in the amounts of volatile m atter and fixed carbon are hardly noticeable below 400°, but become im portant from 400 to 500° and occur up to 700°. Low-grade coal exhibits these changes up to a higher temperature than bituminous coal. The amount of volatile m atter decreases w ith increased carbonisation, and constitutes a method of estim ating the degree of carbonisation. Below 400° the content of bitum en-A and-jB increases in high-caking coal and decreases in low- caking and low-grade coals, and in all cases bitumens become readily extractible by heating ; a t about 500° all bitumen disappears. The content of humic substances in brown coal gradually decreases by heating, becoming nearly zero a t 600°. These facts explain to some extent the cause of the change of moisture-absorbing power of coal by heating. C. W. Sh o p p e e.
H eat transfer in the low -tem perature carbonisa
tion of coal. V. C. All iso n (Ind. Eng. Chem., 1930, 23, 839—843).—A formula has been developed to fit the experimental results obtained in a series of nine tests where Pittsburg seam coal was carbonised in vertical cylindrical m etal retorts varying in radius from I -03 to 6-28 in. and a t retort temperatures of 590—780°.
Low-temperature carbonisation was considered to be complete when the centre of the middle of the charge attained a tem perature of 390°, as this was the only definite “ break point ” on the tim e-tem perature curve above the 100° water-evaporation flat section, and is immediately followed by increased heat-penetrability of the charge, as is shown by the increased steepness of the curve. Of the total loss in weight obtained under low-temperature carbonisation conditions, 95% has occurred when this 390° point is reached, for this par
ticular coal. From the formula the carbonising time can be calculated. The formula is extended to retorts of various shapes. The mechanism of heat penetration of a charge of coal is also discussed. H. S. Ga r lic k.
C irculating-stream coke ovens. O. Pe isc h e r
(Stahl u. Eisen, 1930,50, 761—767).—This type of coke oven has twin flues and a portion of the burn t gases is drawn by suction back into the incoming stream of heating gas and air so as to retard the combustion, avoid overheating, and regulate the heat flow from gas to coking retort. A furnace of this kind is described and illustrated diagrammatically, and a brief account is given of its operation with details of the tem perature distribution in the coking chambers and flues, and of the yield of coke, fuel consumption, and methods of charging
and discharging. A. R. Po w ell.
D eterm ination of the sp . gr. and m acro-pore volum e of coke and other porous su b sta n ces. G.
St a d n ik o v (Brennstoff-Chem., 1930, 11, 330—331).—
A piece of coke is immersed in a bath of paraffin wax, the pressure on which is first reduced in order to remove all air from the macro-pores, and is then increased to 1 ‘5—2 atm . When cold the impregnated coke is with
drawn and a piece of suitable size is cut from the mass.
The volume of this piece is determined in a pyknometer, and the wax therein is then extracted with light petrol
eum in a Soxlilet apparatus, recovered by evaporation of the solvent, and weighed. The volume of the wax, calculated from its known sp. gr., gives the volume of the macro-pores. The true sp. gr. of the cokc is. given by wt. of coke/(vol. of impregnated coke—vol. of macro
pores). In metallurgical and gas cokes this figure agrees with the sp. gr. determined directly on the powdered material. I t appears, therefore, th a t the volume of the micro-pores is negligible in these cokes. A similar comparison, however, shows th a t in low-temperature cokes the micro-pores possess an appreciable volume.
A. B. Ma n n in g. D eterm ination of the “ lum p d en sity ” of coke b y coating the surface w ith paraffin w ax . F. G.
Ho ffm a n n (Brennstoff-Chem., 1930, 11, 297—299).—
Weighed pieces of coke are immersed in a bath of paraffin wax a t 125°, are held therein until the bath has cooled to 75°, and are then withdrawn and allowed to drain. The wax thereby penetrates a few mm. into the pores of the coke, b u t leaves a layer of only negligible thickness on the outer surface. The volume of the coated coke is then determined by displacement, using a mixture of alcohol and water as displacement liquid, and a 2-litre beaker as a pyknometer. A simple attachm ent provided with a pointed screw permits the beaker to be filled to exactly the same level each time. By using only a few pieces of coke of total weight a t least 500 g. the density can be determined with an accuracy of ± 0 -1 -—
0-2% . A. B. Ma n n in g.
Reproduction of coke section s. Zip p e r e r and Lorenz (Gas- u. Wasserfach, 1930, 73, -606—607).—
The coke section is coated electrolytically with a layer of metal. I t is then polished and used as a block for printing directly on to ordinary paper.
A. B. Ma n n in g. E xisten ce of tw o varieties of am orphous carbon.
M. Osw a l d (Chim. et Ind., 1930, 24, 280—292).—-Tech
nical amorphous carbons are, in general, intim ate mixtures of two amorphous varieties of carbon, brown and grey, respectively. The brown form is the only truly amorphous modification of carbon, and its forma
tion is favoured by the use of aliphatic substances for carbonisation, by the presence of oxygen atoms in the molecule, by low tem perature of carbonisation, rapid cooling, and high rigidity of the medium. The reverse conditions favour the production of the grey form, which is pseudo-amorphous, giving an X -ray diffraction pattern like th a t of graphite. The grey form is produced by the carbonisation of aromatic compounds and is favoured by the presence of sulphur or nitrogen atoms in the
molecule. E. S. He d g e s.
Liquid products of the b erginisation of coal.
J. M. Pe r t ie r r a (Anal. Fis. Quim., 1930,28, 792—806).
— A sample of coal on treatm ent by the Bergius process
Cl. I I . — Fu e l ; Ga s ; Ta r ; Mi n e r a l Oi l s.
B r itis h C h e m ic a l A b s tr a c ts —B .
975
gave phenols 32%, bases 8-2% , and neutral oil 59-8% ; the initial pressure had b u t little influence on these proportions. The fraction of the liquid products boiling between 95° and 145° contained 52% of aromatic hydrocarbons (chiefly benzene, toluene, and m- and
^-xylenes), 28-7% of paraffins, and 7-3% of unsatur
ated compounds. Among the phenolic products phenol, o- and m-cresols, and pyrocatechol have been identified, whilst pyridine and 2 : 4-dimethylpyridine have been detected in the basic fraction.
H. F . Gil l b e.
E lasticity of production as a factor in the p ro gressive econom y of gas w orks. R. M e z g e r (Gas- u. Wasserfach, 1930, 73, 557—560, 589—595, 607—
612, 627—632, 655—659).—In order to meet the varying demand for gas throughout the year the plant should conform with the following requirements : (a) high elasticity, i.e., high range of variation in the rate of gas production ; (b) low cost of production per unit, with the smallest variation in cost with varying rate of production ; (c) high ratio of cost of operation plus cost of raw materials to fixed charges a t full load ; and (d) ease of control, i.e., possibility of rapidly varying the rate of production. The cost of production and the elasticity of operation with horizontal and vertical retorts and coke ovens have been calculated ; variations in carbonisation time, volatile content of coal, degree of de-benzolisation of the gas, simultaneous production of water-gas in the retort, and addition of rich gas to the gas used for heating the retorts have all been taken into consideration ; the results have been tabulated and plotted. Similar series of results have been calculated for gas generators and for combinations of retorts with generators. In many cases the peak load can be economically covered by the utilisation of carburetted water-gas plants in conjunction with horizontal or vertical retorts. A. B. Ma n n in g.
G as dehydration. K. Fr a n k (Gas- u. Wasserfach, 1930, 73, 637—638 ; cf. Mezger and Pistor, B., 1930, 594).—Gas dehydration by cooling can simultaneously bring about the removal of the naphthalene (cf. Lenze and Rettenmaier, B., 1926, 938). The question is raised as to whether the use of calcium chloride can also lower the naphthalene content of the gas, and whether the life of the solution is affected by the separation of tarry polymerised hydrocarbons. The utilisation of waste heat in bringing about refrigeration of the gas is cheaper than cooling by compression. I t would seem preferable to place the refrigerating plant after instead of before the gas holder because (a) in spite of the oil insulating layer there is a danger of the gas again taking up water, (b) there is possibility of corrosion of the seams of the holder which are not “ w etted ” by oil, and (c) the tem perature of the gas leaving the holder is always lower than th a t entering. A. B. Ma n n in g.
[Gas dehydration.] Mezger and Pisto r (Gas- u.
Wasserfach, 1930, 73, 638).—A reply to F rank (pre
ceding abstract). A. B. Ma n n in g. [G as-w orks’] benzol recovery. F. Go ldschmidt
(Gas- u. Wasserfach, 1930,73, 636— 637).—Some recom
mendations are made regarding details of practice.
The naphthalene content of the wash oil should not be
allowed to rise above 10—-15% or difficulties may arise due to the deposition of naphthalene in the pipes behind the scrubbers or in the purifiers; by cooling the gas before it reaches the scrubbers its naphthalene content may be lowered and the useful life of the wash oil thereby lengthened. Fresh oil should be added to the wash oil t o . replace th a t removed with the benzol.
The first separation of the crude benzol from the wash oil should be carried out ra p id ly ; to avoid undue loss of benzol thereby the condensing system should be provided with a sufficiently large area of cooling surface.
The danger of decomposition in heating the wash oil as high as 130—145° is negligible. Steam-distillation of the benzolised oil can be continued until the benzol content falls to 0-3% . A. B. Ma n n in g.
A bsorption pipette for exact gas an a ly sis.
E. Ott (Gas- u. Wasserfach, 1930, 73, 801—802).—The
“ double pipette,” in which oxygen, carbon dioxide, and carbon monoxide are absorbed in one bulb and hydro
carbons in a second one, has been improved by the addition of a further pipette, packed with glass tubing like th a t used for hydrocarbons and charged with acid iodine pentoxide for carbon monoxide absorption.
Absorption is complete in 1—2 min., and acid vapours must be removed with caustic potash before the reading is taken. The presence of carbon monoxide is indicated by a brown or green coloration on the liquid surface, which disappears when absorption is complete.
G. Ir w i n. D eterm ination of carbon m on oxide in illu m in at
ing ga s. J. Du b o is (Przemyśl Chem., 1930,14, 313—
318).—The time necessary for the complete absorption of carbon monoxide from illuminating gas can be reduced from 60 to 20 min. by shaking the gas twice for 2 min.
with 10 c.c. of acid cuprous chloride reagent, and 3 times with 5-c.c. portions of ammoniacal cuprous chloride. Complete absorption can a1 so be attained by using Damiens’ reagent (acid cuprous sulphate solution) in three 3-c.c. portions, shaking each time for 3 min. ; carbon dioxide, defines, and oxygen must, however, first be removed from the gas, as these are also quantitatively absorbed. R. Tr u szk o w sk i.
Self-carburation of industrial ga ses from brown coal. M. Fr e u n d and E. Becker (Brennstoff-Chem., 1930, 11, 335—337).—Brown-coal ta r and pitch were cracked in the laboratory by being dropped through an electrically-heated tube packed with iron shavings.
The maximum efficiency of gasification, i.e., on the thermal basis, was obtained a t a cracking temperature of 750—800°, and amounted to 48% with the tar, and 37% with the pitch. The composition of the gas produced was dependent principally on the cracking temperature, and only to a small extent on the raw material or the working pressure. A. B . Ma n n in g.
Form ation of benzine and tar from ethylen e by heating under ordinary p ressu re w ith ou t ca taly sts.
H. I. Wa t er m a n and A. J. Tu l l e n e r s (Brennstoff- Chem., 1930, 11, 337—340).—Ethylene was passed through an electrically-heated silica tube, and the variation in the yields of ta r and light oil with tempera
ture were observed. The rate of passage of the gas was about 1 g./min., the tube was 20 mm. in diam., and the
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