The Smoke Tendency Lamp Use in Testing Kerosenes JOHN B. TERRY A,~YDEDWARD FIELD Standard Oil Company of Crrlifornia, San Francisco, Calif.
D
URIXG the last 15 years or so considerable attention has been paid b y oil refiners to the production of high-grade kerosenes for domestic and foreign markets, the application of
THE BASE PLATESUPPORTis approximately 8.5 inches in height, semicircular in shape, with round heavy ring base fitted with leveling screws. AIR HOLESare drilled in the base plate in circular fashion around the screen to allow free entry of air through the screen to the flame. THEHOODis approximately 10.5 inches in height, semicircular in shape, with front glass door, and hinged top containing air holes. It is black inside, and close fitting on base plate.
improved refining processes being attended by the development of more informative and reproducible laboratory testing procedures. I n a previous article (f), t h e present authors described the improved factor lamp and its use in their laboratories for determining the smoke tendency of various grades of kerosene. It has seemed advisable t o redesign the improved factor lamp t o embody such features as portability and compactness, and t o make a precision instrument capable of at least the same degree of reproducibility. These efforts have resulted in the development of a new instrument known as the smoke tendency lamp (Figure 1) which is described below.
Procedure The sample of kerosene under test is poured into the fount up to the filling mark, and a piece of wick 3.5 inches in length is cut and fitted into the wick tube. The protruding end of the wick is to be clean cut and then burned, so that the rounded tip is only just charred. I t should contain no rough edges, and protrude exactly 0.25 inch from the top of the wick tube. The assembled fount is then screwed into place so that on lighting the wick a small flame is obtained. The screen, chimney, and spot plate are placed in position, a small piece of ice is placed on t’he plate, the hood door and top are closed, and the lamp is set aside for about 15 minutes, preferably in a darkened room, to attain equilibrium conditions. At the expiration of this period, the flame height is increased by turning t.he knurled flange of the fount, the spot plate being centered periodically above the chimney by manipulating its control knob below the base plate. A flame height will eventually be reached a t which a smoke spot, is just formed on the bottom of the spot plate, the flame a t this point forming a smoky “tail.” The flame is t,hen turned down slightly and again raised until the maximum height is obtained without forming a smoke spot. At this point the flame height is read on the scale, the eye being placed on a level with the extreme luminous tip of the flame. It is convenient to use darkened glasses when viewing the flame. This reading in millimeters is recorded as the smoke tendency of the sample under test. The flame is then turned low and the procedure is repeated at least once, the average smoke tendency value being reported.
The Smoke Tendency Lamp This instrument consists of the following parts:
THEFOUNTis cylindrical in shape, about 1.5 inches in diameter, and 3 inches in height, with closely fitting top carrying wick tube 0.25 inch in diameter. The fount screws into a housing mounted on the horizontal base plate, fine adjustment being obtained by means of the bottom knurled flange. The wick tube is thus raised within a slightly wider outer tube mounted on the base plate. THEWICKis American Pett, 0.23 inch in diameter. THE SCREENis cylindrical in shape, of 20-mesh brass, 1.5 inches in height, and approximately 1.0 inch in diameter, open a t both ends, and is placed concentrically around the outer wick tube on the base plate. This screen allows uniform entrance of air a t the base of the flame. THEC H I M X E is ~made ~ of heat-resistant, u n i form glass t u b i n g , 7 inches long, 1 inch in outside diameter, a n d 0.03 to 0.06 inch in thickness. The chimney rests on the top of the screen and is held in a vertical position by a side support screwed on to the base plate. THE SCALEis made of B a k e l i t e , b l a c k m i r r o r e d finish, with white line graduations from 0 to 130 mm., and is mounted vertically on the base plate, the zero mark being on a level with the top of the wick tube. THE SPOT PLATEis m o u n t e d on the base plate by means of a vertical rod about 9.5 inches high. I t is of porcelain 1.75 inches in diameter, 0.44 inch in height, and supported horizontally in a ring. The latter is free to move in a horizontal plane by turning the knurled knob a t the right of the fount. THELEVELis mounted a t the front of the base plate. FIGURE1
TABLE I. TESTRESULTS Sample
A B
C
D
A
B
C
D
Smoke Tendency Lamp Inspector h Inspector B Mm. Mm. Laboratory 1 35, 35 36 60, 61 62 69, 69 69 80, 79 80 Laboratory 2 37 37 64 65 68 69 80 80
Improved Factor Lamp Inspector A Mn. Inches
76 83
1.50 2.60 3.00 3.25
37 66
2.60
86
3.40
39 66
74
l,45
2.90
Results With care and proper attention t o details, results on duplicate samples should agree within 2 mm. (0.07874 inch). This degree of reproducibility is obtained only when the equipment is kept in good condition; the screen should be kept free of dust and lint, the chimney clean and polished. Tests results obtained on four kerosenes, compared with those on t h e same samples by the improved factor lamp, are given i n Table I. 1t:will be noted t h a t the smoke tendency lamp gives values slightly lower than the improved factor lamp. However, t h e 33
INDUSTRIAL A S D ENGINEERING CHEMISTRY
34
VOL. 10, NO. 1
various grades of kerosene are rated in the same order and are tested with equal precision.
of opinions and comments from members of the Inspection Laboratories at Richmond and El Segundo.
Acknowledgment
Literature Cited
Acknowledgment is hereby made of the valuable assistance of P. S. Williams of the Manufacturing Engineering Department i n developing various mechanical improvements, and
(1) Terry, J.
B.,and Field, Edward, IXD. ESG CHEY.,Anal. Ed., 8,
293 (1936). RECEIVED September 23, 1937.
Fractionating Device for Vacuum Distillations E V A 1 NOON,IN, Columbia L-niversity, 4ew- York, N. Y.
S
EVERAL devices have been described for removing fractions of distillate without interrupting the course of a distillation under reduced pressure. Thorne ( 5 ) originated a n apparatus for this purpose which employed three stopcocks, and many modifications and elaborations have since appeared. Sattler ( 4 ) designed a n arrangement t o eliminate some of the difficulties inherent in the earlier types. ,4simple device due to S a s o n (3) is also used, wherein b u t two stopcocks are required. However, the distillation must be interrupted vihile the receiving flask is being evacuated, and this is often undesirable. I n some modifications t h e distillate is collected in a receiver having two chambers, one of which can be restored t o atmospheric pressure and the fraction of distillate withdrawn without disturbing the vacuum in the other chamber. A compact model of this type employing four stopcocks was worked out by Delaby and Charonnet ( 2 ) . One of the most convenient of these de-
Tyj
The stopcock plug is hollow, with two 2-mm. tubes sealed in diagonally, in the manner of an ordinary three-way stopcock. Three 3-mm. holes are drilled through the wall at the smaller end of the plug to communimte with outlets T and G . One hole is drilled in line with the sealed-in bores and communicates with G when the plug is in the position illustrated. The other two holes are drilled a t an angle of 90" to the first. One of them coincides with outlet T when the plug is in the position shown; the other is directly opposite. Tube T enters the shell of the stopcock a t the rear and a t a right angle to the plane of the drawing. The upper end of this tube enters the upper part of the receiver near the connection for the condenser. The condenser tube should be so arranged that liquid cannot enter tube T. Tube L is bent to the rear and the end expanded for rubber tubing connection. The receiver is attached to the condenser a t A , a receiving flask is placed at B, and the pump is connected a t C. The stopcock is then turned to the position shown. The entire system can be evacuated, since ports in the hollow plug communicate with T and G. The distillation is allowed to proceed, and when it is desired to collect another fraction the stopcock is turned 180°, whereupon air or an inert gas is admitted through tube L to the receiving flask. The distillation continues into receiver R, the vacuum being maintained through tube T and the port in the hollow stopcock. A new receiving flask is placed at B , and upon turning the stopcock 90' in the proper direction the receiving flask will be evacuated through tube G, while the rest of the system is momentarily disconnected from the pump. The stopcock is then turned 90" farther and the original position is resumed, the accumulated distillate running into the receiving flask. The receiver, R, may be graduated if desired.
It is impossible t o let air into the system accidentally in excess of the amount contained in the receiving flask if the latter is in place. This is also t'rue of the apparatus as originally designed by Bogert, but unfortunately in many modifications which have appeared this provision has been neglected. I n some designs the connection for a n inert gas is through a stopcock with a "tail" plug, and the tension of the rubber tubing may push it out, I n the device described this is avoided and the plug is held in place by atmospheric pressure. Because of the compact construction the device is not, as fragile as it might appear.
Literature Cited
B
v
FIGURE 1.
vices is t h a t designed by Bogert ( 1 ) 71-hich has a graduat,ed receiver so that fractions of known volume can be collected, and utilizes three stopcocks. I n the device to be described the functions of from two t o four taps are combined in a single stopcock, which is advant,ageous in collecting fractions rapidly.
DIaGRAM O F .kPPARhTWS
(1) Eogert, J. IXD. ESG. CHEY.,7, 785 (1915). (2) Delaby and Charonnet, BuZl. SOC. chim., 43, 1287 (1928). (3) Nason. IXD.EXQ.CHEM.,15, 1188 (1923). (4j Sattler, I h i d . , 17, 583 (1925). (5) Thorne, Ber., 16, 1327 (1893). RECEIVED October 4, 1937.
