Патент USA US2106593код для вставки
Jan- 25, 1938- R. F. DENISTON ET AL 2,106,593 APPARATUS FOR DETERMINING THE DEW POINT OF A VAPOR PRODUCT Filed May 5, 1936 2 Sheets-Sheet 1 0/5771 1 A TE UM: Z0 INVENTORJ WWW, @mlmawég ORNEY Jan. 25, 1938. R. F. DENISTON ET AL ' 2,106,593 APPARATUS FOR DETERMINING THE DEW POINT OF A VAPOR PRODUCT Filed May 5, 1956 2 Sheets-Sheet 2‘ Z9 G45 \__._____'___ CONTROLLER _ 1/6 -‘ _ 1 /0 Eff/DUE LEMWMQI INVENTORJ BY ' Z ‘. v‘ )2 IZATTORNEY Patented Jan. 25, 1938 ' 2,106,593 UNITED STATES PATENT OFFICE 2,106,593 APPARATUS FOR DETERMINING THE DEW POINT OF A VAPOR PRODUCT Robert F. Deniston, Mount Vernon, Ill., and Wen dell P. Hawthorne, Augusta, Kans., assignors to Socony-Vacuum Oil Company, Incorporated, New York, N. Y., a corporation oi.’ New York Application May 5, 1936, Serial No. 77,942 2 Claims. (CI. 73—51) This invention relates to a device for contin uously testing the product‘oi' a continuously op erating distilling, stabilizing, or fractionating device. An object of this invention is to provide a device Cl capable of association with a iractionating device to continuously observe the dew point,.or tem perature of total equilibrium vaporization of the product of such apparatus. C ' Another object is to permit the observation of such quality in such a manner as to permit it to be used for control oi’ the operation producing the product. Other objects and advantages are possessed by this invention, some of which will be referred to hereinafter and some of which will be obvious to those skilled in the art. While pertinent to all distillation operations in which the end boiling point of the product must be controlled to avoid the inclusion of materials 50 heavier than desired, the discussion will be herein limited to motor gasoline for simplicity. Most of the desirable properties of gasoline are tied up with its end distillation point and its volatility. observed in a convenient manner, and the control of equipment automatically accomplished thereby. The dew point oi.’ a vapor is the temperature at which initial condensation occurs when a whole, completely vaporized sample is'cooled. Converse- ‘ 1y, when considering a material such as gasoline, which has a boiling range rather than a boiling point, it is the temperature at which a sample heated under non-vaporizing conditions, will just be 100% vaporized on releasing or "flashing." The dew point is thus a comparatively sensitive measure of heavy material in the product. It has the advantage of having a direct physical significance. Carburetion in an internal combus tion engine, or analogous operations, are in reality “?ash” vaporizations. The dew point, or 100% equilibrium ?ash vaporization point, is directly responsible for completeness of vaporization un der any given conditions and easily correlated therewith. ‘No other commonly observed prop 20 erty is so directly a measure of this valuable char acteristic of gasoline. Vapor pressure alone is only part of the story, because vapor pressure is matically observing, and recording total vapor highly sensitive to percentage of highly volatile components, and relatively insensible to high boiling components. A. S. T. M. distillation end point is not completely signi?cant, because two gasolines of the same end point will vary greatly in ability to be volatilized under given conditions 30 pressure and basing the control onthat have been worked out for application to stabilizers and sim ilar apparatus for the reduction of volatility or upon each other and thus compel interpretation oi.’ results and prevent simple automatic control So great is the truth of this statement that free 25 tionating equipment for the production of gaso line is practically always operated by the control of_ end boiling point on the one hand and total vapor pressure on the other. Methods for auto vapor pressure in excess of that desired. No ‘ simple method has as yet been presented for the 35 automatic control-oi end boiling point. Methods at present used for the control of end because of variation in relative amount oi! lighter - components present. These two properties bear from observation of such properties. Dew point is the one determinable property which ties these things together, and when it becomes possible to continuously observe and record the dew point, it is possible to continuously'control still condi boiling point involve periodic removal of a sam ple, manual distillation in a batch process-the tions in a simple and convenient manner without A. S. T. M. distillation, interpretation of results, the necessity of an operator's interpretation of 40 40 and subsequent change of distillation conditions if the control test has shown this to be necessary. This method presents several di?lculties. Con siderable time elapses between tests, manual con trol is involved, and a chemist’s time is required for the distillation. The results 01' the test are not, in themselves, a direct measure of the char acteristics desirable in the product. The nearest approach to automatic operation of which we are aware accomplishes automatic withdrawal and analysis of sample, but leaves the entire inter pretation of results and adjustment for correction just where it was before. ~ This invention is based ‘upon the discovery that results. ' We have devised an apparatus for continuously observing and recording the dew point and which lends itseli to such control. In order that this device may be more readily understood, reference 45 is now made to the drawings attached to and made a part 0! this speci?cation, in which Figure 1 shows the dew point apparatus and Figure 2 shows the manner in which it may be applied to 50 still control. In Figure 1, which is diagrammatic, 3 is a pipe through which the distillate product to be tested \ is introduced in condensed or partially condensed form to coil 4, placed in heating bath 6, which 55 the dew point of a product may be continuously . is ?lled with a suitable liquid‘ and heated by 55 .51 ‘ 2,106,595; iectrlcal heater: lne heated to in diagrammatic form how this dew point, in this apparatus rgvurc l r the control of a distillation gure ell. b a which feed by coal . which is . is likewise pipe ET, ‘ to 8» below the lowest dew point er ; n th- lower end of coil '9‘ is placed‘. onstru" Material uncon passesthrough trap l0 and is apparatus by pipe ll. Material ~. coil ‘J falls from the lip [2’. at the , end of the coil upon which is preferably nonmagnetic material, and which - supported by solenoid. rod [5, l5. the temperature coll. c dew point, liquid will constantly ‘ e pan it“. pols; and instrument 23 indicates and records it. In this set-up however, instrument 2! has an additional function. Condensate from drum 3!) is returned by pump 33 through pipe 34 as wet re " for control of top temperature of tower " eturned being controlled by valve 23 in this case is also a control 20 instrument, so designed that when the dew point ' .". exceeds ‘ stream corrosion. The inductance bridge consists of solenoid coils l8 surrounding solenoid core M, which supports the pan, and solenoid coils ll surrounding core i8. The inductance bridge is actuated by a source of alternating current 20, which also supplies the various heating services. Without considering in detail the makeup of the inductance bridge, which is well known, its prop erties are such that when actuated by alternating current as shown, the two cores are suspended at certain points as determined by their weights, the properties of the coils, etc., and any change in the position of one is followed by a corre sponding proportional change in the position of the other. Thus, when coil 1 is below the dew point and pan l3 becomes heavy, core l4 moves down, and avcorresponding movement of core i8 relayed by contacts l9 admits current to aux~ iliary heater 2!. When coil 1 is above the dew U! in point, pan 13 becomes lighter, and core I8 is correspondingly moved to cut out heater II. The bath in heating vessel 8 and coil 1 immersed therein are thus kept at the dew point of the vapor analyzed, proportions of bath and coil be 60 ing so selected that “hunting” is minimized. It is of course understood that while direct con tacts are shown at I9, it will probably be prefer able to employ some convenient form of relay system, the direct contacts being shown for sim plicity. Since the bath in vessel 8 is maintained at the dew point of the substance analyzed, it is simple to observe the temperature of the bath or in the trap ID by any convenient form oi’ ther mocouple as 22, here shown in the bath near trap ID, to which is attached the indicating and recording pyrometer designated by 23. a predetermined maximum, "is admitted to tower 24, and when " too low, less is admitted. capable of so acting are own, and of many forms, and 1'10 part of this invention, and motion is consequently indicated ' ‘1'- cm. temperature of the bath and indi ' we and record point. Any springs, etc, mounted. in the vapor 5; exposed to possible gumming and. point analyzer comprising vessels trap Hi, as previously described. rmocouple 22 observes the dew a 3 becomes lighten-until empty. ~' in weight pan i3 is employed to 2 e orefe to employ an inductance ce it enables us to dispense with mov» awn through pipe 3!, and pipe end a continuous sample of dis— 10 5 r vaporate from the pan £3 to the gas stream. bel w the dew pol ‘the pan regularly be» comes hes. --until it filled. Above the dew nose. Cl v "ors pass overhead through pipe 29 to receiver 30. Distillate tillate to a use If the temperature in. dew point, no liquid will drop on and c evaporation will/occur therefrom. temperature above the dew point liquid c product is 32 is provide.' 24 is a. columnar still, to reduced by pipe 26, and heated Residue is withdrawn through a onnection between instrument 23 30' i that equivalents of the device disclosed will occur to those skilled in the art, and it our intention to claim all that is move} 5. ermn, except as limited by the following claims. We claim: Means for continuously observing the dew point of a continuously flowing stream of va porizable substance comprising means Ior con tinuously sampling said stream, means for con verting said sample to a slightly superheated va 40 por, a tube through which said vapor flows, a heater to maintain said tube at a temperature below the dew point of said vapor, said tube in cluding a trap, pan in said trap, means to di rect condensate formed in said tube on said pan, an auxiliary heater for said tube, means respon sive to the weight of the condensate in said pan to control said auxiliary heater to add more heat in response to an increase and less heat in re sponse to a decrease in condensate, whereby said tube is maintained at the dew point temperature of said vapor, and means to observe the tempera ture of the tube. 2. Means for continuously observing the dew 55 point of» a ?owing stream of vaporizable sub stance, comprlsing means to extract a sample therefrom, means to convert such sample to a slightly superheated vapor, means to cool such vapor to a controlled temperature, means to col 60 lect any condensate so formed in a position ex posed to uncondensed vapors, means actuated by the amount of condensate collected to so con trol the cooling temperature that the condensate amount tends neither to decrease nor increase, and means to observe the controlled temperature. ROBERT F. DENISTON. WENDELL P. HAWTHORNE.