US 2798135 A
Description (OCR text may contain errors)
July 2, 1957 GRAHAM 2,798,135
LIQUID LEVEL CONTROL MEANS Filed Jan. 27, l95 6 2 Shets-Sheet 1 ZVENTOR.
Arrow/5Y5 F. O. GRAHAM July 2, 1957 LIQUID LEVEL CONTROL MEANS 2 Sheets-Sheet 2 Filed Jan. 27,- 1956 INVENTOR. a m BY United Brae LIQUID LEVEL CONTROL MEANS Application January 27, 1956, Serial No. 561,786
7 Claims. (Cl. 200-152) This invention relates to improved liquid level control means of apparatus for the simultaneous treatment of gaseous and liquid materials under superatmospheric pressures, of which liquid carbonating apparatus is typical.
It is an object of the invention to provide for such apparatus liquid level electrode control means which is marked by great structural simplicity, compactness and ease of fabrication and which is reliable in operation un der relatively high interior pressures and which by reason of its compactness makes possible greater compactness and lower cost of the apparatus controlled.
With the foregoing objects in view the invention con sists in various forms, arrangements and combinations of parts hereinafter described as embodied in the carbonating apparatus shown in the accompanying drawings, the
said invention being particularly defined by the claims appended to the description.
In the drawings,
Fig. 1 is a vertical sectional view of a carbonator embodying the invention, the section being taken through the vertical axis of the cylindrical carbonator tank or shell, and the figure also including a diagrammatic show ing of automatic means for supplying to the tank liquid to be carbonated.
Fig. 2 is a plan view of the carbonator shown in Fig. l.
3 is a horizontal section on the line 3-3 of Fig. 1.
Fig. 4 is a detached axial sectional view of the electrode parts of the apparatus shown in Fig. 1, the view being on an enlarged scale and a portion of one of the electrodes being broken away to permit the larger scale illustration.
Fig. 5 is a horizontal section on the line 5-5 of Fig. 4.
Fig. 6 is an enlarged side elevation of the electric slip connector for one of the electrodes shown in Figs. 1 and 4.
Fig. 7 is an enlarged shown in Fig. 6.
Fig. 8 is a vertical transverse section of the electrical slip connector of the ground conductor of the apparatus, the section being taken on the line 8-8 of Fig. 5.
Referring in detail to the construction illustrated in the drawings, 1 designates as an entirety a carbonator em bodying the present invention. The carbonator comprises a blank or shell having a seamless tubular side wall 2 of sheet metal, a bottom wall 3 also of sheet metal, and top wall 4 of heavy metal plate, the joints between the side wall and the bottom and top walls, respectively, being suitably welded to provide a hermetically tight vessel.
Within the tank is a baflle structure generally designated by the numeral 5, consisting of a tubular member 6 and a circular apertured disc 7 welded to the lower end of the tube 6, the disc being formed with a central truncated cone part 701. The upper endor" tube 6 is welded to the under side of closure plate 4 so that the baffie structure 5 is rigidly supported in the tank. The upper end of the tube 6 is notched at 6a so that the space inside and outside of the tube are in free communication with each other at the upper end of the carbonator chamber. The
plan view of the slip connector atent diameter of the circular bafile disc 7 is somewhat smaller than the interior diameter of the shell wall 2 so that there is a small circumferential opening a between the periphery of disc 7 and the wall 2.
The closure plate 4 is formed with a threaded aperture to receive a liquid inlet fitting generally designated by the numeral 8 which consists of a tubular part 9 formed at its lower end with a nipple threaded to engage the said aperture in the plate 4, a rubber check valve 10 of conventional type and a pipe coupling member 11 which is threaded into member 9 and secures the check valve 10 in operative position. The lower end of the part 9 is formed with a straight elongated passage 9a designed to introduce liquid under pressure into the carbonator in the form of a solid stream or jet pointed directly toward the upper surface of the bafile disc 7, in a manner to avoid directing the introduced liquid through the opening a.
As shown in Fig. 2, the top plate 4 of the carbonator shell is provided with a fitting 12 for the introduction of carbonic acid gas under pressure. This fitting 12 may be identical with the fitting 8 and adapted for connection to a cylinder of liquified carbon dioxide through suitable pressure control devices in a manner well known in the carbonator art. Diametrically opposite the liquid inlet fitting 8 the closure plate 4 of the carbonator shell is provided with an unthreaded aperture to receive a liquid outlet fitting 13, which is welded in position in the plate with a hermetically tight joint. The upper end of fitting 13 is threaded to receive a pipe coupling. A liquid discharge tube 14, which has its upper end welded in the bore of the fitting 13 with a hermetically tight joint, extends downward to the bottom of the tank chamber where it is curved inward and has its lower open end 14a disposed approximately at the lower axis of the vertical shell and the central bafiie tube 6. The disc 7 is notched at 712 to accommodate tube 14.
Within the baffle tube 6 and extending above the top wall 4 of the carbonator tank is disposed improved liquid ameter to snugly fit the inner wall of the tubular elec trode 16 and support the rod electrode in coaxial relation to the tubular electrode.
The coaxial electrode unit thus formed is mounted in a support fitting 19 by means of an insulating tube 20 which i preferably formed of solid plastic material such as Du Pont nylon. The inner surface of tube 20 has a pressed fit on the electrode 16 and its outer surface has a pressed fit in the bore of the support fitting 19. The upper end of inner electrode 17 extends above the insulating tube 18 and its lower end extends below the lower end of the insulating tube and is threaded to receive an enlarged tip 17a of carbon or graphite in accordance with known practice.
In the fabrication of the electrode unit comprising the electrodes l6, l7 and interposed insulating sheath 18, after the three elements have been telescoped together in the relation shown in Fig. 4, the outer electrode 16 is compressed at a plurality of points along its length to form interior annular beads 16a which compress the plastic sheath 13 as shown in Fig. 4. This creates a corresponding number of zones extending longitudinally of the electrodes in which extremely tight fits are formedv between the outer electrode and the plastic sheath and between the inner electrode and the plastic sheath. The. compressing or crimping operation on the outer electrode is preferably carried out by chucking the three-part electrode assembly in a rotary spindle and forming theseveral internal beads of the outer electrode simultaneously by a spinning operation. By reason of the simultaneous compressing actions it will be seen that the treatment positively compresses the plastic material of sheath 18 occupying the spaces between adjacent beads as well as establishing at the beads very high pressures between the two electrodes and the sheath. The result is that the jointsbetween the respective coaxial electrodes and the interposed sheath are rendered permanently resistant to longitudinal leakage between the electrodes to an extremely high degree.
After the three-part electrode unit has been assembled in the sleeve the latter is forced into the bore of the support 19. In this operation the outer surface of the sleeve 20, or the inner surface of the support 19, is advantageously coated with a suitable varnish such as General Electric Glyptal No. 1294, which serves as a lubricant to facilitate the assembly and which, when hardened, additionally insures a liquid-proof joint. It will be appreciated that in efiecting the force fit of the plastic sleeve 20 in the bore of the support 19 resultant inward pressures are transmitted from the support to the joint between the sleeve 20 and the tubulareletcrode 16.
The lower end of the electrode support 19 is threaded to engage a central threaded aperture in the tank plate 4 'so as to provide a tight joint between the support and the said plate.
It will be noted, in Figs. 1 and 4, that the upper end of the electrode tube 16 extends somewhat above the insulating sleeve 20, thus providing an exposed cylindrical surface to receive the slip connector 21 of a conductor 22 (Figs.f6, 7). The connector 21 is in the form of a helical wire coil of a diameter to slip over the end of electrode 16 by resiliently expanding slightly, the conductor being preferably formed at its upper end with a smaller diameter coil 21a to which the end of conductor 22 is soldered.
Similarly the upper end of the inner electrode 17 which extends above the insulating sheath 18 is adapted to receive a slip connector 23 of a conductor 24 formed similarly to connector 21 but of suitable smaller diameter to fit the smaller electrode.
To provide a ground connection for the electrical sys tern the conductor support 19 is formed with an upwardly extending collar having an inner cylindrical surface 19a in which is slidably disposed a resilient expansible connector 25 which is connected to a ground conductor 26. The connector 25 is in the form of an interrupted band (Figs. 5, 8), to permit its contraction and expansion, and is formed intermediate its ends with a loop 25a to receive the end of the conductor 26 and facilitate the making of a soldered joint.
The collar of support 19 also is formed with a cylindrical outer surface 19b to receive a tube 27 of a height to surround the lower ends of the cable 28 and its conductors 22, 24, 26. After the slip connectors of the three conductors have been applied to the electrodes and the support 19 as shown in Fig. 4, the space Within the tube 27 may be filled with a suitable sealing material 29 such as epoxy resin. Thus sealed, the upper part of the entire electrode assembly and the electrical connections thereto are rendered completely water proof.
As is shown in Fig. 1, the cable conductors 22, 24 and 26 are extended to a relay 30, which, in turn, is connected to the terminals of an electric motor 31 which drives a rotary pump 32 connected to supply Water or other liquid to the fitting 8 of the carbonator. The motor driven pump and the electrode control means operate in known manner to automatically supply liquid to be carbonated and the electric devices diagrammatically indicated in the drawing may be of known character such, for example, as those shown in U. S. Patent No. 2,249,994.
The top closure plate 4 of the tank 1 is preferably provided at a point diametrically opposite the gas inlet fitting" 12 with a threaded aperture to receive a relief J valve 32 (Fig. 2), such as is commonly provided for carbonator apparatus of the character in question.
In accordance with the usual practice all parts of the carbonating apparatus which are contacted by the carbonating liquid are formed of corrosion-resistant metal, such as stainless steel.
With the carbonator connected to a source of CO2 gas adapted to supply the gas at a suitable pressure, such as l00 p. s. i., and with the liquid pump connected with a source of liquid and designed to supply liquid to the carbonator fitting 8 at a pressure of 120-140 p. s. i., the operation of the apparatus is as follows.
The motor driven pump under control of the electrodes is started and stopped to maintain the level of the liquid in the carbonator between the maximum and minimum levels coinciding with the lower ends of the electrodes 16 and 17, respectively. When, because of draft of carbonated liquid through discharge tube 14, the liquid level in the carbonator falls below the bottom of the electrode tip 17a and the pump 24 is thereby started, liquid at the pump discharge pressure is delivered through'thc bore 9a of the supply-fitting 8 until the liquid level in the carbonator rises to the bottom of the shorter electrode 16, whereupon the pump is automatically stopped. The liquid is delivered through the bore of the fitting 8 in the form of a solid jet which is projected into the body of liquid in the carbonator-at high velocity and causes the liquid to vigorously boil and bubble in the presence of the compressed gas which is maintained under the predetermined supply pressure. The space surrounding the bafile tube 6 and above the baffle disc 7 is thus occupied by a vigorously agitated mass of mixed liquid and gas and the large liquid surfaces thus developed favor rapid solution of the gas in the liquid. However, the space within the baflie tube 6 is relatively quiescent so that the electrodes are able to perform their motor control function with adequate uniformity. The space below the bafiie disc 7, although it is in communication with the space above the disc through the restricted circumferential opening a, is also relatively quiescent. Nevertheless, during withdrawal of carbonated liquid from the carbonator, the space below disc 7 to a substantial. extent receives small bubbles of undissolved gas which pass downward with liquid through the opening a. As this mixture of liquid and bubbles moves from opening a downward and radially inward toward the inlet opening 14a of the discharge tube 14 the bubbles rise and find their way into baffle tube 6 where they move upward through the quiescent liquid and deliver their gaseous contents to the gas space above the liquid level in the carbonator. The use of the distinctively formed and arranged jet nozzle, bafile structure and carbonated liquid discharge tube herein disclosed is not herein claimed since it is the subject of claims in U. S. patent to Lance, No. 2,735,665.
It will be understood that in the operation of the carbonator it is subjected to an interior pressure at least equal to the carbonated gas pressure employed and that the joints of the carbonator structure must be hermetically tight. Since level-controlling electrodes supported in the carbonator chamber must be insulated from the metal walls of the chamber the attainment of reliably tight joints between the electrodes and the carbonator'tank wall have always posed a somewhat difficult problem. In the present carbonator this problem has been solved with notable success by means of the construction which has been described. The relatively small diameter of the threaded section of the support fitting 19 facilitates the attainment of a tight joint between the support and the top plate of the carbonator. Similarly the forced fit of the plastic sleeve 20 in the bore of the fitting 19 and on the tubular electrode 16 insures permanently tight joints between these parts. Finally, the series of the annular beads 16a formed in the electrode 16 with resultant high compression of the insulating sheath 18 between the two electrodes in a plurality of zones, produces joints between the sheath and the electrodes capable of withstanding extremely high pressures without leakage of gas.
As will be noted in Fig. 1 of the drawing, the small diameter of the electrode assembly permits the use of a small bafiie tube 6. This, in turn, permits some reduction in the diameter of the tubular side wall 2 of the carbonator tank without sacrificing the volumetric capacity of the agitation zone of the carbonator and the result is a reduced materials cost of the tank and bafiie structure.
The construction of the coaxial electrode assembly achieves additional savings in cost by virtue of reduction of the amounts of the construction materials employed, the utilization of standard rod and tubular forms for the metal electrode members and the ease with which the assembly of the electrode parts and the electrical connections is effected.
It will be understood that the specific constructions of the improved carbonator which are herein disclosed and described are presented for purposes of explanation and illustration and are not intended to indicate limits of the invention, the scope of the invention being indicated by the following claims.
What is claimed is:
1. Electric liquid-level control means of apparatus for the simultaneous treatment of gaseous and liquid materials under super-atmospheric pressure, the said means comprising the combination with a hermetically closed metal tank for holding gas and liquid to be treated; of a metal tube-like electrode support having a gas-tight mounting in the top wall of the tank to provide a passage therethrough; a bushing of solid dielectric material disposed in the passage through the support with a gas-tight forced fit therein; a tubular metal electrode extending upward through and somewhat above the upper end of the bushing and having a gas-tight forced fit in the bushing; and a rod-shaped electrode unit of greater length than the tubular electrode extending through the latter with a gastight fit, the said unit comprising a metal rod and a deformable dielectric tube tightly fitting the rod with portions of the rod exposed at each end of the dielectric tube and the said tubular electrode being formed with a plurality of annular inwardly projecting beads that highly compress the wall of the dielectric tube between the surfaces of the beads and the surface of the electrode rod.
2. Control means as claimed in claim 1 in which adjacent annular beads of the tubular electrode act also, in conjunction with the tubular and rod electrodes, to maintain the material of the dielectric tube disposed between the adjacent beads in a state of positive compression.
3. Control means as claimed in claim 1 which additionally comprise three electrical conductors, two of which have end fittings having resilient slip engagement with the upper ends of the tubular and rod electrodes, respectively, and the third of which has resilient slip connection with the upper end of the electrode support.
4. Control means as claimed in claim 3 in which the conductor fittings for slip engagement with the electrodes each consists of a primary helical wire coil formed to slip over and resiliently grip the upper end of its electrode and a secondary coil integrally attached to the primary coil and soldered to its conductor.
5. Electric liquid level control means of apparatus for the simultaneous treatment of gaseous and liquid materials under super-atmospheric pressure, the said means comprising the combination with a hermetically closed metal tank for holding gas and liquid to be treated; of a metal tube-like electrode support having a gas-tight mounting in the top wall of the tank to provide a passage therethrough and being formed at its upper end with an upstanding annular collar; a bushing of solid dielectric material disposed in the passage through the support with a gas-tight forced fit therein; a tubular metal electrode extending upward through and somewhat above the upper end of the bushing with a gas-tight fit therein; a rodshaped electrode unit of greater length than the tubular electrode extending through the latter, the said unit comprising a metal rod and a deformable dielectric tube surrounding the rod with portions of the rod exposed at each end of the tube and forming a gas-tight packing between the rod and tubular electrode elements; two electrical conductors having resilient slip engagement with the upper ends of the tubular and rod electrodes, respectively; a third conductor having a resilient slip engagement with the inner surface of the annular collar of the electrode support; an upstanding tube having its lower end tightly engaing the outer surface of the collar of the electrode support; and a solid body of dielectric material filling the upstanding tube and forming a water-proof cover for the lower end parts of the three conductors.
6. Electric liquid level control means comprising a metal tube-like electrode support; a bushing of solid dielectric material disposed in the passage through the support with a fluid-tight forced fit therein; a tubular metal electrode extending upward through and somewhat above the upper end of the bushing with a fluid-tight fit therein; a rod-shaped electrode unit of greater length than the tubular electrode extending through the latter, the said unit comprising a metal rod and deformable dielectric tube surrounding the rod with portions ofthe rod exposed at each end of the tube and the said tubular electrode being formed with a plurality of annular inwardly projecting beads that highly compress the wall of the dielectric tube between the surfaces of the beads and the surface of the electrode rod; and three electrical conductors, two of which have end fittings having resilient slip engagement with the upper ends of the tubular and rod electrodes, respectively, and the third of which has a resilient slip connection with the upper end of the electrode support.
7. Electric liquid level control means comprising a metal tube-like electrode support formed at its upper end with an upstanding annular collar; a bushing of solid dielectrical material disposed in the passage through the support with a fluid-tight fit therein; a tubular metal electrode extending upward through and somewhat above the upper end of the bushing with a fluid-tight fit therein; a rod-shaped electrode unit of greater length than the tubular electrode extending through the latter, the said unit comprising a metal rod and a deformable dielectric tube surrounding the rod with portions of the rod exposed at each end of the tube and forming a fluid-tight packing between the rod and tubular electrode elements; two electrical conductors having resilient slip engagement with the upper ends of the tubular and rod electrodes, respectively; a third conductor having a resilient slip engagement with the inner surface of the annular collar of the electrode support; an upstanding tube having its lower end tightly engaging the outer surface of the collar of the electrode support; and a solid body of dielectric material filling the upstanding tube and forming a water proof cover for the lower end parts of the three conductors.
References Cited in the file of this patent UNITED STATES PATENTS 1,962,192 Hapgood June 12, 1934 2,414,607 Phillips Jan. 21, 1947 2,424,657 Goodman July 29, 1947 2,470,066 Calabrese May 10, 1949 2,514,463 Bayers July 11, 1950 2,623,969 Lyle Dec. 30, 1952 2,735,665 Lance Feb. 21, 1956