US3123541A

US3123541A - donnell

Info

Publication number: US3123541A
Authority: US
Publication date: 1964-03-03
Anticipated expiration: 1981-03-03

Description

March 3, 1964 c. K. DONNELL 3,123,541

CONTINUOUS DISTILLATION ANALYZER Filed Nov. 1, 1960 2 Sheets-Sheet 1 Fig. .3

Indicating Temperature Controller Feed l6 Sample In Cooling Liquid In I8 44 Condensate Residue Integrator and Recorder 25 Dlstilled) 40 I Drop Producmg Drop counting; IL 0 f8: iirf 'z g Circuitry P W Remote CAR I INVENTOR.

L, CONARD K. DONNELL ATTORNEY March 3, 1964 c. K. DONNELL CONTINUOUS DISTILLATION ANALYZER 2 Sheets-Sheet 2 Filed NOV. 1, 1960 INVENTOR. CONARD K. DONNELL.

ATTORNEY United States Patent 3,123,541 CUNTINUGUS DISTILLATIGN ANALYZER Conard K. Donnell, Springfield, Pa., assignor to Sun Oil Company, Philadelphia, Pa., a corporation of New Jersey Filed No 1, 1960, Ser. No. 66,593 4 Claims. (Cl. 202-160) This invention relates to a continuous distillation analyzer.

In the refining of petroleum, gas oils which are to be charged to catalytic cracking units should contain a minimum of gasoline-boiling-range material. This is because such a relatively low-boiling traction passes through the cracking unit essentially unchanged, and remains in the catalytic gasoline as low-octane component, depressing the octane rating of the catalytic gasoline.

According to prior practice, the amount of gasoline (low-boiling fraction) in the gas oil charge was determined by means of a batch distillation procedure, using a long-neck distilling flask containing jack-chain packing. The aforementioned procedure was carried out in accordance with Method 13-285 of the American Society for Testing Materials (ASTM). The distilling flask referred to is called a Hempel flask, and the distillation procedure has become known as the Hempel distillation. Usually, the volume percent of the charge distilled at 410 F. and 440 F. vapor temperature is reported.

As previously stated, the conventional Hempel distillation is carried out in batch-wise fashion, in the laboratory. Such batch-wise operation in the laboratory involves considerable delay in the obtaining and reporting of results, which is quite undesirable, and in addition requires manual handling and transporting of samples, which can become rather laborious.

Another type of distillation procedure which is quite common is the so-called Engler or ASTM distillation. In this procedure, the temperature at which a certain percentage (e.g., 50%, 70%, 90%, etc.) ofthe charge has boiled oil or gone overhead is determined, and the results are reported in temperature values, usually for the 10%, 50% and 90% points of the charge. Here again, prior practice dictated batch-wise distillation, in the laboratory.

An object of this invention is to provide a novel distillation anayzer, usable for either Hempel distillations or Engler distillations.

Another object is to provide a Hempel-type distillation analyzer which operates continuously and automatically, to give a continuous record of the percent of sample distilled at 440 F., or at any other desired, predetermined temperature.

The objects of this invention are accomplished, briefly, in the following manner. Two spaced concentric tubes are arranged to serve as a combined distillation vessel and condenser. The inner tube is heated to an elevated temperature, while the outer tube is provided with a jacket through which a cooling fluid (e.g., air or water) fiows. The inner tube may therefore be thought of as an evaporator, while the outer tube may be thought of as a condenser. The sample to be analyzed is continuously fiowed at a known and constant rate onto the outer surface of the inner tube, so as to flow downwardly therealong. A portion of the charge or sample vaporizes at the temperature of the inner tube, and travels as vapor to the outer, cooler tube, upon the inner Wall of which it condenses. It then flows downwardly as condensate. For a Hempel distillation, the drops of condensate or distillate are counted, as by means of a capacitance-type drop counter. In this way, the rate of production of condensate is measured or determined. The residue,

"ice

which remains unevaporated at the elevated temperature of the inner tube, flows downwardly along the inner tube, and is abstracted from the bottom of the apparatus. Since the rate of feed to the vessel is known and preset, and since for a Hempel distillation the rate of condensate or distillate production at the elevated temperature of the evaporator is measured by counting and integrating the drops, the percent of the charge which is distilled at the said elevated temperature can readily be calculated. For an Engler-type distillation, the temperature of the inner tube is controlled so as to maintain a substantially constant drop rate through the drop counter aforementioned (thus maintaining a fixed and known percent overhead, since the feed rate is known), and the temperature of the inner tube is measured.

A detailed description of the invention follows, taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a schematic representation, partly in longitudinal cross-section, of a continuous distillation analyzer according to this invention;

FIG. 2 is a longitudinal, vertical cross-section through the drop producing and sensing unit utilized in the invention;

FIG. 3 is a transverse cross-section taken along line 3-3 in FIG. 2; and

FIG. 4 is a vertical cross-section taken along line i -4 in FIG. 2.

Reference is now made to the drawings, and first to FIG. 1 thereof. A hollow outer tube 1, made for example of glass, is provided with a jacket 2 through which a cooling fluid (erg, air or water) is circulated, by means of the hose nipples 3 and 4 provided at the upper and lower ends, respectively, of the jacket 2. An inner hollow tube 5 is mounted and supported concentrically Within the outer tube 1, for example by means of a flange 6 secured to the upper end of tube 5 and resting on the top of tube 1. Tube 5 is made from some material that is a good conductor of heat, such as nickel-plated copper. The tube 5 may in some cases comprise two separate sections 5a and 5b rigidly fastened together, end-to-end, the upper section 5a being a thin-walled tube and the lower section 512 being a solid cylinder in which there is provided a longitudinal bore whose length is almost equal to the length of the cylinder. The common longitudinal axis of tubes 1 and 5 is vertical, so that the tubes 1 and 5 are vertical, as illustrated in FIG. 1.

For convenience, the analyzer of this invention will be described first as used for a Hempel-type distillation. Thereafter, there will be described the use of the same analyzer (of the invention) for an Engler-type distillation.

A cartridge-type heater 7 is positioned within the bore in the lower tube section 5b, the electrical leads to this heater being indicated at 8. Heater 7 functions, as will be described later, to heat tube 5 to a substantially fixed predetermined (elevated) temperature. The lower end of tube section 51) is made of frusto-conical shape, as illustrated in FIG. 1, and is counterbored from its lower end to receive a thermocouple 9 to'which are connected a pair of electrical leads 10. Leads 10 extend downwardly through a drain tube 11, to be later described, to the bottom of the analyzer, and thence out through a cap 12 to an indicating temperature conroller 13. A suiable liquidtight seal is provided in cap 12 around leads 10, to prevent any leakage of fluid through cap 12. Cap 12 is provided with external threads, whereby a suitable electrical conduit may be coupled thereto. Temperature controller 13 may be of the pyrometer type, including a milliammeter to measure the output of thermocouple 9, and this controller is supplied at 14 with alternating current power for heater energization purposes. The heater leads 8 extend up through body section 5a and are connected to the output or controlled side of controller 13, Controller 13 is actuated from the thermocouple 9 (which is responsive to the temperature of tube 5), and this controller operates to control (by means of an on-oil signal) the energization of heater '7 (which is inside the lower end of tube 5) so as to maintain the temperature of tube 5 substantially constant. The temperature of tube 5 is maintained substantially constant at a predetermined temperature, e.g., 405 F.

The inner diameter of flange 6 is, for a substantial portion of the axial length of this flange, made somewhat larger than the outer diameter of upper tube section 50, thereby to provide an annular space 15 at the upper end of tube 5. At its upper end, space 15 (whose lower end is open) communicates with the inner end of a radiallyextending conduit or coupling 16. Th outer end of coupling 16 is connected to the discharge side of a feed pump 17, which operates to continuously pump the sample to be analyzed, at a known and constant rate, into coupling 16 and through the latter to the upper end of annular space 15. pumped to the top of annular space 15', from whence it flows downward over the outer surface of vertical tube 5 in a thin film, since the lower end of annular space 15 is open. Pump 17 may be a gear pump, of the type known as a metering pump.

In order to distribute the flow around the entire periphcry of tube 5 in the form of a thin film, it has been found necessary to in eifect provide a modification of the outer surface of tube 5, from a smooth cylindrical surface. Otherwise, the flow would take place only in two or three narrow streams, over only a small portion of the periphery of tube 5. One expedient which has been found effective to distribute the flow more evenly is to first wind a piece of still wire tightly around a hexagonal mandrel, then remove the mandrel and place this same wire (in spiral form) rather tightly around the outside of tube 5, so as to cover substantially the entire length of this tube. Due to its having been wound around a hexagonal mandrel, the wire does not continuously contact the cylindrical outer surface of tube 5, so that at the corners of the hexagon the wire is spaced from the outer surface of tube 5. This leaves sufficient room for the liquid to flow rather freely over the outer surface of tube 5, yet the wire distributes the flow around the entire periphery of such tube. The expedient just described has not been illustrated in FIG. 1, as it is felt that to do so would unduly complicate the drawings.

The open upper end of a small-diameter drain tube 11 is located somewhat below the lower frusto-conical end of tube section 512. The thermocouple leads pass down through the length of tube 11, as previously described. The lower end of tube 11 is welded through a disk-like flange 18 which seals off the bottom end of tube 1. A cap 19 is fastened near the lower end of tube 11, this cap extending transversely to the axis of tube 11 and having a bore extending entirely therethrough; the inner end of the aforesaid bore communicates with the tube 11. Cap 19 is provided with external pipe threads, whereby a drain pipe may be coupled thereto.

At its bottom end, tube 1 has a standard (tapered) pipe flange 26. The lower end of tube 1 engages a gasket 21 which is positioned in an annular gasket recess provided in the upper face of the lower flange 18. Just inside of the inner diameter of recess 21, and radially outwardly beyond tube 11, a piece 22 of stainless steel tubing is welded entirely through the lower flange 18, this piece of tubing extending downwardly from flange 18 at a small inclination (say 10) outwardly from the vertical, and the upper end of this tubing terminating more or less flush with the upper surface of flange 18. In order to seal the lower end of outer tube 1 against leakage around its periphery, an upper flange 23 is utilized. Flange 23 has therein a central tapered aperture whose taper matches that at 2%. Flange 23 is provided with a set of six evenly- In this way, feed or sample (i.e., liquid charge) is ,isasai spaced tapped holes which extend through the thickness dimension of the flange and which match respective drilled holes extending through the thickness dimension of flange 13. Screws 24 extend freely through the holes in flange 18 and thread into the tapped holes in flange 23. By tightening screws 24, flange 23 is urged downwardly toward flange 18, thus bringing the lower end of tube 1 into sealing engagement with the gasket in recess 21.

Since inner tube 5 is heated, it may be termed an evaporator. Since outer tube 1 is water-cooled (by means of jacket 2), it may be thought of as a condenser. The tubes 1 and 5 together form a distillation vessel.

These components or fractions of the charge supplied at to (which charge flows downward in a thin film over the outer surface of tube 5, as previously described) which boil at or below the temperature of the heated tube or zon 5 are vaporized or boiled off from the inner tube. These travel as vapor to the second or cooled zone (water-cooled tube 31), and are condensed on the inner surface of tube 1. This condensate or distillate flows downwardly along the surface of tube 1 to the bottom of the analyzer, and thence outwardly through tubing 22.

The undistilled residue (to wit, that portion of the charge which boils above the temperature of tube 5, and hence is not distilled in the analyzer) runs down over the low-er frusto-conical or thermocouple end of tube 5 and thence down into drain tube ill, from whence it emerges from the analyzer by way of drain fitting 1?. Thus, it may be seen that elements 11, 1% comprise a means for abstracting from the analyzer (or distillation vessel ll, 5) that portion of the liquid charge which boils above the (predetermined) temperature of tube 5.

Since the feed rate is maintained constant by pump 17, the rate of distillate or condensate flow (through tubing .--.2) is a direct measure of the percent distilled at the predetermined temperature (the temperature of tube 5, say 405 F). Thus, by measuring the flow rate of the condensate or distillate, the percent distilled at a temperature may be readily determined.

The flow rate of a liquid stream can be measured conveniently, in the low flow rate ranges below about ten cc. per minute, by counting drops falling from an orifice. By properly designing the orifice, the size of the drops can be maintained constant over a considerable range of flow rates.

The drops can be counted automatically, the usual detector being a lamp and photocell arranged so that each drop interrupts the light beam momentarily, and produces a pulse output from the photocell. However, such an arrangement as this requires careful alignment of the lamp and photocell with respect to the falling drops, so that each drop actually interrupts the beam sufiiciently to be detected. Failure of the lamp, of course, inactivates the system, and aging of components can aflcct its sensitivity enough to render it inoperative.

According to this invention, a capacitance system is used to count falling drops of liquid, as a means of measuring flow rates. According to this feature of the invention, the liquid condensate flowing in tubing 22 is first formed into drops, and the drops are caused to pass between the vertical plates of a small parallel-plate condenser whose plates are sufliciently close together so that a single drop momentarily fills a major fraction of the space between the plates. The liquid, acting as a diflerent dielectric (i.e., different from air) for the condenser, alters the capacitance thereof sufficiently to be detected readily. The condenser plates are arranged so that each drop flows clear of the plates rapidly, with the result that the capacitance returns to its normal (lower) value before the next succeeding drop falls. The pulses resulting from the individual drops are integrated to give a DC. voltage proportional to the drop rate, which voltage is recorded.

The condensed distillate issuing from tubing 22 flows as at 25 through a drop producing and sensing unit 26,

which in conjunction with a remote capacity unit 27 and drop counting circuitry 28 produces an electrical pulse for each drop issuing from the drop producing portion of unit 26. The constructional details of unit 26 will now be described, with reference to FIGS. 2-4.

The drop producing and sensing unit components are all contained or supported in a tubular housing 29 of insulating material. A dripper 30, designed to produce drops of a uniform size, is mounted with a sliding fit in the upper end of housing 29. Dripper 36% has an intermediate cylindrical body portion 30a of a diameter such as to fit within housing 29, and an upper body portion 30b of larger diameter, the junction between

body portions

30a and 30b forming a shoulder 31 which rests on the upper end of the hollow cylindrical housing 29. Dripper 30 has an internal funnel-like liquid passage therein, comprising an upper inverted frusto-conical surface 32 the lower (and smaller-diameter) end of which opens into a longitudinal bore 33 which extends vertically downwardly from the lower end of surface 32 Below the lower end of intermediate body portion 30a, there is a lower cylindrical body portion 3tic whose diameter is much smaller than that of body portion 390. Bore 33 extends down into body portion 30c, and is bottomed at the lower end of body portion 30c. It is desired to be pointed out that, although body portion 3&0 has been described as a lower body portion, actually the dripper body extends below portion 36c (as will later become apparent), and bore 33 terminates above the extreme lower end of the dripper body.

At the lower end of bore 33, four holes 34 spaced 90 apart are drilled from the outside of the dripper body portion 301: into communication with bore 33. The axes of holes 34 extend at right angles to the axis of bore 33, that is, the axes of these holes are horizontal. Below body portion 300, the dripper body is flared outwardly (by means of a frusto-conical section 319d) to a cylindrical terminal body portion 3% whose diameter is about 1 /2 times the diameter of body portion 360. The lower face of body portion c (and also of the body 30) has a sharp edge and constitutes a fiat horizontal bottom surface which is circular in shape.

As previously stated, the elements 3a3e and 3134 comprise a dripper. The liquid condensate 25 emerging from the open end of tubing 22 (see FIG. 1) is guided by surface 32 into bore 33, the liquid then flowing down this bore and emerging from the lower end thereof by way of holes 34. The dripper 30 is shaped to produce drops of a uniform size. The liquid emerging from holes 34 flows downwardly over the outer surface of body section 360', and the drop forms on the flat horizontal bottom surface of body section 3%, from which it drips downwardly toward the bottom of housing 29.

Adjacent the terminal body portion 30e, a pair of inspection holes 35 (located 180 apart around the housing 29) are drilled through the wall of housing 29.

The parallel-plate condenser previously referred to is mounted in housing 29, in such a position that the drops of condensate produced by dripper 30 can pass downwardly between the condenser plates. Two vertically disposed metal plates 36, each having an area of about /2 in. x /2 in. and a thickness of A in., comprise the parallel plates of the capacitor or condenser which is used for sensing the drops of condensate. The plates are separated by an air gap 37 of to A in.; by way of example, this gap may be 20 mils (0202. in.) in thickness. The upper end of each plate 36 is downwardly beveled as at 38, to guide the drops into the gap 37 between the plates.

Although it is not illustrated in the drawings, the plates 36 may each he provided with a coating of insulating material (such as the tetrafluoroethylene material known as Tefion). This prevents sh'ont circuitin-g of the plates by drops of water which may be present in the condensate. If no water is expected to be present in the con- 3 dens-ate, it would be preferable to omit this insulating coating from plates 36, leaving these plates bare.

The plates 36 are supported each in a respective one of the two insulating spacers 39, which are substantially semicircular in horizontal cross-section and the length of which exceeds that of the plates 36. Each of the spacers a recess cut therein into which the respective plate 36 fits, the recesses being rectangular in horizontal crosssection and having arouate bottoms (see FIG. 4), the plates 36 also having arcuatte boto-ms. The juxtaposed faces of the spacers 39 are separated throughout their lengths by a gap which is commensurate with gap 37; thus, there is a gap which extends diametrically entirely across housing 29 (see FIG. 3), and there is a gap which extends throughout the lengths of the spacers 39 (see FIG. 2).

Beginning at a plane below the lower (arcuate) ends of the plates 36, each of the spacers is formed with an inverted semi-conical surface; when in assembled position, these surfaces of the two spacers combine in effect to provide a conical surface whose tip or apex is located considerably below the lower ends of the plates.

It will be recalled that, in effect, the gap 37 between the plates continues uniformly (below the lower ends of the plates) down between the insulating spacers 39, to the tip or apex of the cone formed 'by the two insulating spacers. Thus, in effect, the lower ends of the plates 36 are extended with insulating material, so that the drops can flow smoothly through the plates 36, and clear them before the next drop falls. After reaching the apex or tip of the (inverted) cone formed by spacers 39, the drops continue downwardly and out the lower open end of housing 29.

In order to maintain the

parts

36 and 39 in assembled position within housing 29, two screws 40 are utilized. Each of the screws 49 is essentially perpendicular to the length of gap 37, and each extends through respective aligned holes drilled through housing 29 and a respective spacer 39 and threads into a tapped hole in a respective one of the plates 36. Thus, the plates 36 and spacers 39 are maintained in their proper positions in housing 29. At the same time, the screws 40 provide a means for making a separate electrical connection to each respective metal plate 36. These connections may be made by wires 41 (see FIG. 1) connected each to a respective screw 40.

A condenser or capacitor with the dimensions set forth has a capacitance, with dielectric, of 1 to 2 micrornicrofarads. Drops of hydrocarbon liquid (condensate or distillate) between the plates approximately double this capacitance, since the dielectric constant of the hydrocarbon is approximately twice that of This capacitance difference, or change, is adequate to give reliable operation of a capacitance detecting circuit.

The leads 41 from the parallel plates. 36 are intended to be short, and extend to a remote capacity unit 27, from which a line 42 (which may be long) extends to the input of drop counting circuitry 28. The remote unit 27 matches the high impedance of the sensing or measuring device to the low impedance of the line 42. From the output of the counting circuitry 28, a connection 43 extends to the input of'an inte'grator and recorder 44. The

units

27, 28, and 44 form no part of the present invention, so will'not be described in detail herein. For a more complete description of these units, reference may be had to the copending Bachofer application, Serial No. 68,712, filed November 14, 1960. For the present, suifice it to say that the drop counting circuitry 28 functions to produce an output pulse corresponding to each drop passing between the plates 36. These pulses are rectified and integrated by unit 44 to provide a DC. voltage proportional to the drop rate, or rate of flow of distillate (condensate). This latter voltage is recorded in unit 44 to provide a record of the distillate flow rate in the analyzer of FIG. 1. Since the feed rate or charge rate (at 17) is known and is maintained constant, the distillate rate is a direct measure of the percent distilled at the (predetermined) temperature of tube 5.

The temperature at which the evaporator tube is operated, in the continuous analyzer of this invention, must be chosen by experiment. Because the distillation vessel disclosed herein is fundamentally different from the ordinary Hempel flask, the degree of fractionation is dillerent. At equivalent temperatures, more distillate is produced in the continuous analyzer than in the batch Hempel flask. Therefore, to obtain the same percentage distillate, the evaporator temperature must be lower in the continuous analyzer. For example, in one typical application of the continuous analyzer of this invention, the evaporator tube 5 is operated at 405 F., in order to obtain the best correlation with batch (conventional-type) results at 440 F. This is the reason for the previous references to 405 F., in the above detailed description of the continuous analyzer of this invention.

Furthermore, even under these conditions there is not a oneat-o-one correlation between the continuous and batch distillations. By way of explanation, a sample that results in 2.5% distilled at 440 F. (batch or laboratory distillation) will result in 2.5% distilled at 405 F. (continuous distillation, using the apparatus of this invention). However, if the distillate percentage (by batch distillation) decreases to zero, the continuous analyzer will still show 1% distillate; if the distillate percentage (by batch distillation) increases to 6%, the continuous analyzer will show only about 4%. But, this lack of a one-to-one correlation between the continuous and batch methods has no effect on the actual operation of the continuous analyzer of the in tendon, and at any rate can be overcome if necessary by applying suitable correction factors to the results obtained with the continuous analyzer.

The capacitance-type drop counter described herein is particularly useful at rates of 1 to 10 drops per second past the condenser plates.

As previously stated, the preceding description has referred to the use of the analyzer of the invention for a Hempel-type distillation, wherein the temperature of tube 5' is mm'ntained at a substantially fixed, predetermined value, and wherein the percent distilled (percent overhead) at this temperature is measured by means of the capacitance-type drop counter described. However, the analyzer is equally applicable to so-called Engler-type distillations. For such distillations, heater 7, instead of being controlled by the temperature-responsive controller 113, is controlled by the output of the drop counting circuitry 28. The control of the heater is made to occur in such a way as to maintain the drop rate through the sensing unit 26 substantially constant, and at a predetermined value; this would correspond, of course, to a fixed percentage overhead (such as 50% or 95%), since the feed rate to the analyzer is known and constant. Typical circuitry for such control of the heater is disclosed in the'above-mentioned Bachofer application. In this type of distillation, the temperature of tube 5 (which then corresponds to the temperature at which a certain known percentage of the charge goes overhead) is measured, as by means of thermocouple 9.

In some instances of the application of the analyzer to Engler-type determinations, the drop producing and sensing unit 26 may be coupled to drain tube 11, so as to sense the residue (rather than being coupled to tubing 22, so as to sense the condensate). Such sensing of the residue may be particularly advantageous when the 95 point of the charge is being determined, since then the 95% overhead may involve too high a rate of flow through tubing 221501 proper operation of the capacitancetype drop counter described; on the other hand, the 5% residue involves a flow rate which is appropriate for the drop counter.

The invention claimed is:

1. A continuous distillation analyzer comprising a hollow outer tube provided with a jacket; means for circulating a cooling liquid through said jacket, an inner tube mounted concentrically within said outer tube, controllable means for heating said inner tube, means responsive to the temperature of said inner tube for controlling said controllable means to maintain said inner tube at a substantially constant elevated temperature, means for continuously flowing, at a known rate, a liquid to be analyzed onto the outer surface of said inner tube, and means for determining the rate of production of all of the liquid which is boiled off from said inner tube and collects as condensate on said outer tube.

2. A distillate analyzer as defined in claim 1, wherein the determining means includes a parallel-plate capacitor arranged so that the condensate is received between its plates, as a dielectric.

3. A continuous distillation analyzer comprising a hollow outer tube provided with a jacket; means for circulating a cooling liquid through said jacket, an inner tube mounted concentrically within said outer tube, controllable means for heating said inner tube, means responsive to the temperature of said inner tube for controlling said controllable means to maintain said inner tube at a substantially constant elevated temperature, means for continuously flowing, at a known rate, a liquid to be analyzed onto the outer surface of said inner tube, means for determining the rate of production of all of the liquid which is boiled off from said inner tube and collects as condensate on said outer tube, and means adjacent one end of said inner tube or continuously abstracting that portion of the analyzed liquid which is not boiled off from said inner tube.

4. A distillation analyzer as defined in claim 3, wherein the determining means includes a parallel-plate capacitor arranged so that the condensate draining oil said outer tube is received between the plates of the capacitor, as a dielectric.

References titted in the file of this patent UNITED STATES PATENTS 1,845,159 Lea Feb. 16, 1932 2,117,802 Hickman May 17, 1938 2,180,052 Hickman et a1. Nov. 14, 1939 2,240,618 Harris Mar. 6, 1941 2,363,247 Holder NOV. 21, 1944 2,392,893 Williamson Jan. 15, 1946 2,450,098 Smith Sept. 28, 1948' 2,530,376 Castle et a1. Nov. 21, 1950 2,577,615 Garrison et al. Dec. 4, 1951 2,595,948 Jones May 6, 1952 2,615,706 Davey Oct. 28, 1952 2,616,839 Arnes Nov. 4, 1952 2,650,085 Burnett Aug. 25, 1953 2,772,393 Davis Nov. 27, 1956 2,785,374- Fay et al. Mar. 12, 1957 3,009,364 Webb NOV. 21, 1961 OTHER REFERENCES Instruments and Process Control, published by NY. State Vocational and Practical Arts Association, 1945, pp. -185.

American Journal of Clinical Patholog vol. 26, No. 12, December 1956, pp. 1439-1449.

Claims

1. A CONTINUOUS DISTILLATION ANALYZER COMPRISING A HOLLOW OUTER TUBE PROVIDED WITH A JACKET; MEANS FOR CIRCULATING A COOLING LIQUID THROUGH SAID JACKET, AN INNER TUBE MOUNTED CONCENTRICALLY WITHIN SAID OUTER TUBE, CONTROLLABLE MEANS FOR HEATING SAID INNER TUBE, MEANS RESPONSIVE TO THE TEMPERATURE OF SAID INNER TUBE FOR CONTROLLING SAID CONTROLLABLE MEANS TO MAINTAIN SID INNER TUBE AT A SUBSTANTIALLY CONSTANT ELEVATED TEMPERATURE, MEANS FOR CONTINUOUSLY FLOWING, AT A KNOWN RATE, A LIQUID TO BE ANALYZED ONTO THE OUTE SURFACE OF SAID INNER TUBE, AND MEANS FOR DETERMINING THE RATE OF PRODUCTION OF ALL OF THE LIQUID WHICH IS BOILED OFF FROM SAID INNER TUBE AND COLLECTS AS CONDENSATE ON SAID OUTER TUBE.