ANALYSIS, REFINING, AND COMPOSITION. 



31 



stance, if there is an increase of pressure in the Moain chain! KM- K, 

 there is a corresponding increase of pressure on the bottom of the 

 diaphragm and the diaphragm moves upward, closing the valve D 

 until the pressure is again normal in E. 



SEPARATORS. 

 I 



The separator, figure 17, is the same in principle as the ordinary 

 automatic oil and water separator used in practice, but it is made 1 

 much more compact in order that only a small amount of oil can be 

 retained in it at one time. This apparatus can be 

 made entirely from ordinary iron pipe and pipe 

 fittings. A separator like that shown in the draw- 

 ing, with a total length of 3 feet, and with the main 

 tube made of 2^-inch iron pipe, was sufficient for 

 the separation of 20 to 23 gallons of refined turpen- 

 tine from about the same amount of water per hour. 



SPEED INDICATORS. 



The speed indicator, 1 figure 18, is based on the 

 principle that there is a definite relation between the 

 rate of flow of a liquid through a small aperture 

 and the pressure of the liquid at the aperture. The 

 liquid, as for instance the refined turpentine, enters 

 the indicator from the separator through A. The 

 only outlet for the liquid is the tube C, which may 

 be entered from the top or through the aperture 

 D, this aperture is made small enough so that, with 

 the normal flow of the liquid, it is necessary for the 

 liquid level to rise some distance in the tube B in 

 order that the pressure may be sufficient to make the 

 liquid flow through D at the same rate it enters 

 through A. The height of the liquid level in B 

 is a measure of the rate of flow through D, and 

 the relationship between these factors is obtained 

 by calibration; that is, by measuring the rate of 

 flow from C while the liquid level is maintained at 

 constant measured distances above D. The cali- 

 bration curve for the crude-turpentine indicator is shown in figure 19. 



FIG. 18. Speed In- 

 dicator. 



1 This apparatus can be made almost entirely from ordinary iron pipe and pipe fittings. 

 The pipe C should, however, be of brass so that the aperture D may not be changed in size 

 by rusting and, of course, the tube B must be of glass. The method of fastening the 

 glass tube into the iron parts is shown in the drawing; E is a support of tin plait- or 

 other thin, easily shaped, metal soldered to the nipple in order to support the tube B 

 and packing F ; G is a thin layer of litharge and glycerin cement, which makes the joint 

 oil or water-tight. 



