IL31511A - Apparatus for the cracking of organic materials in the liquid phase by an electric arc - Google Patents

Description

Apparatus for the cracking of organic materials in the phase by electric arc 29745 The present invention concerns on improved apparatus for by submerged intermittent electric organic substances in the liquid hydrocarbons and their substituted derivatives such as either by themselves or in for the purpose of producing a gaseous The constituents of the gaseous mixture thufe on the nature of the ing the composition of the starting mixture may adapted for production of gaseous mixture of a desired A method the production of gaseous mixtures already been which i in an arc being struck between two electrodes submerged in a liquid which arc is interrupted according to a predetermined This is achieved by imparting to a least one of the electrodes a reciprocating motion which the electrodes into contact with each other for striking the arc and them apart for its French Patent describes a process of this type which produces gaseous mixtures rich in acetylene and having an excellent energy yield and being in by that the electrodes are mounted so as to undergo an impact at the moment of their mutual contact before the arc is y this impac the surfaces of the electrodes are from the undesirable carbon deposits which are Inevitably formed on the extremities of carbon A first type of reactor designed to this process a axlally adjustable fixed insulated from the body of the apparatus and connected throug an mediate inductio coil to a transformer su l in a sin hase current of ops at a voltage of order of 500 and a mobile rig bearing a corresponding electrodes which performed a rectilinear reciprocating motion providing the intermittent contac between the fixed and the mobile electrodes necessary for their cleaning and striking the a movement obtained by means of a mechanism driven by a synchronous motor at 3000 A appropriate phase displacement of this relative to the phase of current permitted the of the electrodes at a certain at the beginning of the alternation when the instantaneous voltage had reached a value for necessar a sure initiation of the arc while its extinction was caused automatically by the joint effect of the moving apart and voltage passing through its at the end of the alternation cycle inversion of industrial of an apparatus so conceived has to the construction of a mobile equipment of considerable which has to displaced within the liquid hydrocarbon medium at a rate o 3000 times per minute a path of the order of 60 mm distance found necessary for a voltage of 500 volts applied to the arcs in and it been proved practically difficult to find a lasting mechanical solution for performing such a such an apparatus necessitates the use of reactors in order to full exploit a the motions of the mobile sys of the units being by relative to each In order to overcome these has been in the first certificate of addition to the Frnh P te t rectilinear movement of the mobile electrode b ah alternating and particularly a pendular In an apparatus thus designed the two alternations of could readily be utilized owing to the mounting of electrodes symmetrically on either side o a mobile set carrying electrodes symmetrically positioned in This last type reactor has been functioning with a voltage of 500 a current intensit of 1000 amperes and a curvilinear path which could be adjusted up to 120 but the mechanical troubles created by such a motion have prevented its satisfactory and lasting operation at the speed of 3000 er The present invention has the object to eliminate the mechanical difficulties described while retaining the excellent results as concerns the yield of by under certain a rotatory motion of mobile electrodes cooperating with the fixed Apparatuses the cracking of liquid hydrocarbons by a submerged electric in which mobile electrodes perform rotatory motion relative to fixed are because of certain mechanical peculiarities which oommon to them these apparatuses present serious drawbacks which have rendered impossible thei real commercial As a matter of in all know apparatuses of this the longitudinal axis of the mobile electrodes is perpendicular to the ails of rotation of the mobile equipment carrying As a rule these electrodes are fixed radially along the periphery of a disc which rotated around an axis passing through and brought into cooperation with fixed electrodes around that disc at equal most of the arrangements thus proposed require that no contact exists between the mobile the fixed and this is a cause of their bad Experience has shown that such absence of contact the electrodes in a medium highly as the liquid carbons has especially the resul that the voltage at which the arc struck is much too high for a oltage arc the Carbon deposits which are inevitabl formed on the extremities of carbon accumulate without being cleaned off and soon put the apparatus out on the other it is attempted to establish in such an apparatus a contact between the and fixed this contact could only be punctual because the end face of each mobile electrode moves along a curved and not a planar such a punctual contact is uncertain and cannot ensure the stability of striking of the arcs which is indispensable to the good functioning of the owing to the fact tha the mobile electrodes rotate about a axis perpendicular to their longitudinal wear of the electrodes in the course of their operation causes shortening of the path of the mobile electrodes and consequently of length of the This phenomenon entails either the use of too low an voltage from the outset of operation which results in a poor or a gradual drop of the voltage the of operation as ihe voltage between the terminals of an arc is known to be substantially proportional to the length of arc the range of high intensities industrially drop of voltage results in a gradual drop in power which harmful to the industrial exploitation where constancy of production rates is the apparatus according to the invention which comprises in a manner known in electrodes fixed on support at regular angular intervale along a circumference concentric wit the axis of rotation of the the mobile electrodes and the cooperating electrodes are so that the free ends of the mobile electrodes successively contact the free ends of the fixed electrodes plane normal to axis rotation of the support of the mobile and means are provided for the adjustment of the position of the fixed electrodes relative to the mobile In carrying out the invention any of pairs of mobil electrodes may be provided for two fixed The diameter of the circumference along which these electrodes distributed determined by the available in such a that thei linear displacement i the of one hal the current responds to the lengt of the arc resulting from that given For with a voltage of 500 volts and a current the planar contact the mobil should each describe a section of a circular of a circumference of about 150 mm which corresponds to a diameter of rotation to a distance between the fixed of approximately 100 With phase current n and an apparatus comprising mobile the speed of rotation in is given b the It should be mentioned that several apparatuses of this invention can be juxtaposed or combined in order to enable the of a multiphase For a current one may provide two pairs of oppositely fixed electrodes and between them a rotating rig carrying on each face a set of mobile electrodes coordinated to one of the pairs of fixed Independentl of the fact that the apparatus according to the present invention presents all the advantages of known rotary as concerns the path which can be utilized for the arcs and the rational exploitation Of the ternations of alternating it should be stated that the arrangement of the plane of contact of the perpendicular to the axis of rotation of the mobile has the of ensuring the constancy the path described by whatever the wear of the this path corresponds an equally constant voltage which results in an optimum yield and an improved possibility of industrial the apparatus according to the invention achieves an excellent contact between the entirely comparable to achieved by a reciprocatory movement of the since in both cases this contac takes between the plane surface the respective extremities of the and fixed by pressure in the case of reciprocatory by friction in the of the rotary movement in accordance with the This results a very high stability of the which is required for the prope operation o the friction is caused between the end surfaces of the and mobile electrodes ensures a constant cleaning of the carbon deposits which form on these surfaces i the course of the and the means provided for adjusting In carrying the invention practice it found desirable to adopt certain special arrangements concerning the structure o the support of the mobile electrodes and their mounting on the The first attempts made wit a mobile rig consistin of a disc provided with sockets into whic the cylindrical electrodes were inserted wit pressure have show that by the rotation of the support in the liquid organic substance to be the electrodes easily reach velocities of movement of at which there form zones of stron depression i the wake of each The arc which had bee struck at the end of the electrode is thereby drawn to the rear thereof and very soon destroys the metallic electrode holder to such an extent that the submitted to repeated breaks very According to a preferred embodiment of the invention these disadvantages are avoided by designing the rotary support of the mobile electrodes in the form of spokes radially mounted on a common hub in a number corresponding to that of the mobile which spokes at their ends facing the fixed the mobile electrodes inserted in the spokes with their front ends the sense while their projecting rear ends are arrangement does not abolish the depression in the wake of the mobile electrodes but it eliminates the destructive effect of the arc since this now springs from resistant carbon instead of from the supportin socket and destroying by consumin its As a matter of the manner of mounting the electrodes according to embodiment leaves a part of their surfaces free so that the arc can conveniently spring from spokes carrying the mobile electrodes are preferably penetration into the material to be The mobile electrodes are advantageously designed in the form of trapezoid prisms whose one basis forms the planar contact surface of the and the electrodes can be locked within their sockets by In o the stresses which the usually carbonaceous electrodes to withstand it is advisable to make from a sufficiently strong The mechanical parameter relevant to the estimatio of this quality in the beadin this purpose one may use graphite which possesses a high mechanical strengt and especially a bending strengt above 300 The accompanying drawings by way of a example an embodiment of an apparatus according to the In these is a diagrammatic of an apparatus comprising two mobile electrodes cooperating with two fixed electrodes 2 is an on a larger the mobile systemj 3 is a Of the mobile seen in the direction of the arrow As shown in the apparatus comprises a reaction vessel 1 filled with the liquid material to be At 2 and fixed electrodes are at of two supports which are horizontally placed one above the and which project into the tank 1 through joints provided in one of the lateral walls of the position of these electrodes can be adjusted for example by means Of a mechanism and These electrodes are to the electrical supply through transformer 1 an appropriate impedance Inside the vessel 1 and the is disposed a rig comprising two mobile fixed on a support generally designated which secured to a horizontal shaft 11 projecting into the vessel through a stuffin box 12 provided in side wall the vessel opposite to the wall carrying the fixed electrodes A rotating the direction indicated by the arrow can be Imparted to the shaft by an electromotor In the embodiment shown in greater detail in 2 and the support 10 comprises two spokes fixed a commo hub from either side which they extend radially and symmetrically in to the axis the shaft The is keyed On the shaft 11 by means of a key with a calculate the mobile and fixed electrodes at the moment when the instantaneous voltage reaches the suitable value for a sure striking of the The spokes represented here as blades an outline substantially in the form of a circular whose surfaces facing the fixed electrodes comprise a planar portion and a portion inclined in the direction of the rotation indicated by the arrow The mobile electrodes designed in the form of prisms having a of trapezoidal and they inserted in diametrically opposite positions in sockets of a corresponding extending through the full thickness of th spokes in such a manner that the bases of contact of the electrodes project from the front sides of spokes facing electrodes while their opposite bases project from the rear sides of the Bach the stem of a piece whose head is positioned on the rear side of spokes to which it is fastened a screw B way of experiments concerning the of kerosene were carried out with an apparatus of the type described above comprising fixed electrodes of graphite of 32 mm diameter encased in and mobile electrodes of graphite of trapezoidal of x 50 mounted on a rotary with a voltage of 750 volte of alternating current at 50 a current strength of effective amperes and a speed of rotation of the reactor of 3000 have produced a regular discharge of 250 of crude gas havin the following composition by acetylene and higher alkynes 35 ethylene and olefins 15 methane and higher a 4 The average electric power was 700 k with cos energy consumption was kW per of the gaeeous product insufficientOCRQuality

Claims (1)

1. 6. An. apparatus according to any of Claims 1 to 5, wherein the mobile eleetrodes are designed in the form of trapezoidal prisms, one base of which constitutes the planar surface of contact of the electrode. 7. An apparatus for the cracking of organic substances in the liquid phase by a submerged intermittent electric arc generated between fixed electrodes and mobile electrodes which latter are mounted on a rotary support at regular angular intervals along a circumference concentric with the -axis of rotation of the support, substantially as described herein and illustrated In the accompanying drawings. ND.ea