Abstract:
A tool for crushing coke includes a casing which in the operational state is connected to a drill rod and on or in which is arranged at least one cutting nozzle and one drill nozzle for drilling coke and at least one valve for controlling a direction of flow of water flowing through the drill rod and the casing through the cutting nozzle and the drill nozzle.

Description:
CROSS REFERENCE TO RELATED APPLICATION(S) 
     This application is a divisional application of pending U.S. patent application Ser. No. 11/578,456, filed Aug. 8, 2007, entitled TOOL FOR CRUSHING COKE, by Wolfgang Paul et al. 
    
    
     BACKGROUND 
     1. Field of the Invention 
     The invention relates to a tool for crushing coke, including
         a casing which, in the operational state is connected to a drill rod and on or in which   at least one cutting nozzle each for cutting and one drill nozzle for drilling of coke and   at least one valve for controlling a direction of flow of the water flowing through the drill rod and the casing through the cutting nozzle and the drill nozzle is arranged.       

     2. Background Art 
     In oil refineries the last, otherwise no longer usable fraction of the crude oil is converted into coke. The conversion is brought about by feeding this fraction into drums which, as the operation proceeds, become filled with coke. Once the maximum filling level of the drums has been attained, the coke is cut out of the drums. 
     This so-called “de-coking” is conventionally performed with high pressure water jets which crush the coke and flush it out of the drums. The tool for generating these high pressure water jets is introduced by way of a drill rod mechanism from above into the drum. The “de-coking” is performed in two steps. To begin with, an aperture is drilled by the tool in the drum, then the tool is, once again, taken to the upper end of the drum and the coke is now crushed by high pressure water jets generated by the cutting nozzles approximately at about right angles to the axis. 
     The tool which is, for example, known from WO 03/01461 A1 representing the genus, is accordingly designed for two operating conditions, firstly for the drilling of an aperture which is necessary for moving the tool and for the subsequent discharge of crushed coke and, secondly, for the cutting of the coke across the cross section of the drum. Accordingly, the drill nozzles direct high pressure water jets essentially parallel or at an acute angle to an axis, which is formed by the drill rod and by the aperture formed during drilling. The cutting nozzles, on the other hand, generate high pressure water jets which are directed essentially at right angles or at a shallow angle to the axis formed by the drilling rod and the aperture in the drum. 
     The change-over between the operational states of drilling and cutting must proceed rapidly and simply. The nozzles which are used in the tool, due to the high water pressure, suffer wear and tear and must be replaced at regular intervals. Accordingly, the tool must be so designed that a replacement of the nozzles can be performed rapidly and reliably. 
     The wear and tear of the nozzles is increased by the fact that in known tools of the afore mentioned type, water under high pressure is forced into an annular space which communicates with all nozzles, from where the water enters non-directionally into whichever nozzles are openedm in the course of which no reorientation whatsoever of the flow in the direction of the respective nozzles takes place. 
     In another tool as well, known from DE 39 41 953 A1 the feeding of water under pressure to the cutting nozzles and to the drill nozzles proceeds initially in a central piston and from there, depending on the position of the piston in the casing of the tool, through apertures traversing the wall of the piston into one or two annular cavities of which one is connected to the cutting nozzles and the other is connected to the drill nozzles. The pressurized water flow is subjected in the piston to vortex formation and, only after having suffered corresponding pressure and flow losses, passes by way of the apertures in the wall of the piston into radial ducts in which the water is conducted to the nozzles. 
     In the tool known from U.S. Pat. No. 5,816,505 as well, two annular cavities of this type are provided to each of which the pressurized water is conducted, as a function of a control bringing about either the drilling mode of operation or the cutting mode, with considerable flow losses and forwarded from the respective annular cavity by way of ducts connected there to the nozzles. 
     SUMMARY OF THE INVENTION 
     The invention has as an object to provide a tool for crushing coke which has a particularly simple design as well as permitting reliable insertion and maintenance. 
     The invention attains this object by means of a tool in accordance with claim  1 . Advantageous further developments of the inventive concept are reflected in the dependent claims. 
     Characteristic features of the tool according to the invention are at least two flow passages formed inside the casing, which respectively extend between individual feed apertures associated with the respective drill passage and the respective cutting and drilling nozzles. The valve for controlling the direction of flow of the water to the cutting nozzles or the drilling nozzles respectively, is, in this context, accommodated in the region of the feed apertures, and, depending on the prevailing operating conditions, generally cutting or drilling, closes the corresponding feed apertures of the individual flow passages. 
     The flow passages which, within the scope of the invention, represent individually separated regions, extending between the feed apertures and the outlet apertures provided in the region of the associated nozzles, permit the feeding of the water with only very low flow losses in a directed manner to the respective nozzles. As a result of the thereby achieved reduction of the disturbing effects acting on the nozzles, the life expectancy of the individual nozzles, as compared with conventional tools, can be increased substantially. 
     This minimizing of the flow losses as well as the optimizing of the flow within the tool, in addition, permits feeding the water through the tool with a supply pressure, which is lower than with known tools whilst maintaining the same discharge pressures from the valves. 
     Accordingly, the design according to the invention also permits increasing the life expectancy of the components which act in conjunction with the tool such as, e.g., a supply pump, due to the reduction of the pumping output. 
     A further advantage of the tools according to the invention results from the circumstance that the feed apertures which are closable for regulating the direction of flow of the water, can be combined at an optional, constructionally advantageous locality of the tool, so that even a plurality of mutually independently arranged nozzles can be controlled using a single valve. 
     Accordingly, the employment of a multitude of valves, as are particularly required when using a plurality of nozzles, which preferably have to be arranged in a single plane, can therefore be dispensed with so that the tool in accordance with the invention can be manufactured in a very compact form and at low cost, and, moreover, has a particularly simple construction. 
     Depending on the design of the valve and the arrangement of the feed apertures it is possible, in principle, to control the direction of flow of the water by the tool in an optional manner. 
     By being adapted to the predominating purpose of using the tool, this is in an advantageous manner designed for the two operational states of cutting and drilling, in the operational state of cutting, the feed apertures to the drilling nozzle and in the operational state of drilling, the feed apertures to the cutting nozzle being closed by the valve. 
     This further development of the invention permits reducing the number of valve bodies in the valve required for the closing of the feed apertures, such that the valve can be designed particularly simply, this resulting, in particular, in a further reduction of the manufacturing costs and an increase of the functional reliability of the tool, additionally to the afore going. 
     The arrangement of the flow passages as well as of the feed apertures in the tool can be freely selected subject to constructional and hydro-dynamic preconditions. 
     According to a further development of the invention, the feed apertures are, however, arranged essentially normal to the direction of flow of the water flowing through the drill rod and the casing. In this context the direction of flow will, as a rule, correspond to the longitudinal axis of the tool and of the drill rod, so that the flow apertures then extend transversely to the longitudinal axis of the tool. 
     This further development of the invention permits a particularly compact design of the tool. More particularly, the constructional space requirements of the tool transversely to its longitudinal axis are reduced, because the valve bodies, in contrast to known tools, need no longer be arranged immediately adjoining the nozzle and, therefore, between the nozzle and the interior of the tool. Moreover, the twisting forces arising when readjusting the valves is reduced considerably as compared with known tools. 
     If constructional considerations permit, the flow passages may be formed in one piece with the casing. However, a simplification of the manufacture is attained according to an advantageous embodiment of the invention in that the flow passages are formed as an installation module to be installed in the casing. 
     The arrangement of this module is preferably so brought about that no water will bypass between the module and the inner wall of the casing, which might otherwise have adverse effects on the main flow. This is preferably brought about by a non-positive or positive connection of between the module and the casing of the tool with the aid of screws or the like. 
     In that respect it is unnecessary in designing the flow passages to take the configuration of the casing of the tool into consideration, so that the flow passages which, according to a further development of the invention, has a hydro dynamically optimized configuration, preferably follow a rounded-off pattern, the cross section of the flow passages according to a particularly advantageous further development, being optionally designed in the desired manner such that it changes from the feed aperture to the cutting and/or drilling nozzles. 
     The use of a separate installation module moreover makes it possible to employ therefore a material which differs from the material for the casing and which is particularly suitable for the construction of the flow passages but, because of possibly higher cost, is only used to a limited extent for the manufacture of the casing. 
     An additional improvement of the flow through the casing may be attained in that at the end of the flow passages facing the nozzles, flow unifiers are provided which improve the flow performance of the water through the nozzles in a supplementary manner. 
     The valve for controlling the flow through the feed apertures may, in principle, comprise optionally designed valve bodies. According to an advantageous further development of the invention, however, the valve comprises valve bodies which, at least in sections, are of spherical configuration which close the feed apertures according to the particularly elected operational state. 
     The spherical configuration of the surface sections ensures that the entry to the respective feed apertures to be closed, are securely sealed against the passage of liquid. A circularly shaped disc, one side of which is spherically convex would, for example, entirely satisfy the requirements of closing the feed apertures. 
     Accordingly to a particularly advantageous further development of the invention the valve bodies, however, include at least two spherical surface sections and are preferably of symmetrical design. As a rule, these spherical surface sections are, in this context, provided on opposite sides, e.g. as spherical caps which are mutually adjoining along their maximum circumferences. The symmetrical design of the valve bodies offers the advantage that, because of their symmetrical design, they can be easily guided in the valve. On the other hand, they offer the advantage that, in the event of a first spherical surface section having suffered some wear, the symmetrical valve body can simply be turned around. Whenever that happens, another spherical cap with a second spherical surface section can now be used for sealing the feed apertures. 
     As compared with spheres serving as valve bodies which, according to a further advantageous embodiment of the invention, may likewise be used, and in which, because of the complete symmetry, any positional securing of the valve body can be dispensed with, the symmetrical valve bodies are to be given preference whenever the diameter of the valve body directly affects the dimensions of the tool, because such valve bodies have a lesser thickness than spherical valve bodies. 
     According to a first embodiment the valve is accommodated in the interior of the casing and comprises means for guiding, in particular half shells which embrace the valve body when these are in engagement with the feed apertures. 
     The means for guiding these valve bodies are accommodated in the valve where the latter, however, as a rule, does not fill the casing entirely. Accordingly, clearances are present between the valve and the casing. According to an advantageous further development of the invention these clearances communicate with the interior of the tool so that the liquid which, in operation flows through the tool may also flow through these clearances. The advantage of this arrangement is that no pressure drop prevails in the tool between the interior and the clearances between the casing and the valve. Accordingly, the valve can be designed in a material-saving manner, because no pressure differences leading to corresponding compressive and tensile forces need to be accommodated. In addition to this, the avoidance of pressure differences ensures the smooth performance of the valve. 
     The arrangement of the valve may, in a preferred manner, be such that the valve bodies are automatically pressed by the internal pressure prevailing in the casing on to the feed apertures to be closed. According to an advantageous further development of the invention, the valve bodies, however, are biased by a spring element in the direction towards the feed aperture. This further development of the invention improves in a supplementary manner the functional reliability of the valve and ensures in a particularly reliable manner that the valve bodies will enter into engagement with the particular selected feed apertures and close in a liquid-tight manner. 
     The switch-over from the operational state “drilling” to the other operational state “cutting” takes place manually in most prior art tools. After the first processing step the tool is withdrawn from the drum and a device fitted inside the tool is actuated which, after conclusion of the drilling step process, closes the downwardly directed drilling nozzles and opens the cutting nozzles. 
     This device for the closing of individual or a plurality of nozzles, on the one hand, is in engagement with the valve, and on the other hand provides an aperture for accommodating an operating element which is to be actuated from the outside of the tool. In order to avoid accidents when operating the de-coking tool, the device for operating the valve, in accordance with an advantageous further development of the invention, is provided in that region which faces towards the drilling rod, that is to say above the nozzles, so that even in the event of failure of any control- and warning devices, the operating personnel can approach the tool without the risk of serious injuries arising. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the following a working example of the invention will be described with reference to the drawings. Dependent claims relate to an advantageous embodiment of the invention. In the drawings there is shown in 
         FIG. 1  a first sectional view in longitudinal direction of an embodiment of the tool according to the invention in the operating condition “drilling”; 
         FIG. 2  a second sectional view in longitudinal direction of the tool according to  FIG. 1  in the same section plane in the operative condition “cutting”; 
         FIG. 3  a sectional view of the tool according to  FIG. 1  along the section line A-B of  FIG. 1 ; 
         FIG. 4  a plan view on to an assembly module of the tool according to  FIG. 1  for the accommodation of flow passages; 
         FIG. 5  an elevation, half of which is in section of the module according to  FIG. 4  along the section line A-B of  FIG. 4 ; 
         FIG. 6  a sectional view of the module according to  FIG. 4  along the section line C-D according to  FIG. 5 ; 
         FIG. 7  a sectional view of the module according of  FIG. 4  along the section line E-F of  FIG. 4 ; 
         FIG. 8  a perspective view of a valve of the tool according to  FIG. 1 ; 
         FIG. 9  a front elevation of the valve according to  FIG. 8 ; 
         FIG. 10  a reversed plan view of  FIG. 8 ; 
         FIG. 11  a sectional view of the valve according to  FIG. 8  along the section line A-B of  FIG. 9  and 
         FIG. 12  a sectional view of the valve according to  FIG. 8  along the section line C-D of  FIG. 10 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIG. 1  shows a tool  2  including a casing  4 , four nozzles  34 ,  41 —two nozzles  41  for the drilling of coke, two nozzles  34  for the cutting of coke—of which only two have been illustrated, an assembly module  30  comprising four flow passages  31 ,  47 , as well as a valve  20  for opening and closing of feed apertures  32 ,  37  (see  FIG. 4 ) provided in the module  30 . 
     In its operational state the tool  2  is suspended from a drill rod which is not shown in detail and is introduced into a drum filled with coke. References such as “top” or “bottom” relate to the longitudinal axis A which is aligned with the drill rod (top) and a bore (bottom; not illustrated) generated by the tool  2 , in the context of the tool  2  illustrated in  FIGS. 1 and 3 , as well as the components illustrated in  FIGS. 2 and 4  to  12 . 
     The casing  4  is constructed in two parts and is composed of the upper casing half  4   a  and the lower casing half  4   b  which are interconnected with the use of screws  7  extending through the lower casing half  4   b  and engaging threaded bores in the upper casing half  4   a.    
     A cavity  50  in the lower casing half  4   b  ensures the unimpeded liquid flow through the flow passages  31  to the drilling nozzles  41 , which are accommodated in corresponding bores  48  in the lower casing half  4   b  and are secured in their position by screws  42 . An annular gasket  43  provided in the region of the contact areas of the drilling nozzles  41  against the bore  48  serve to seal the interior of the tool  2  against the environment. 
     The upper casing half  4   a  is fitted by way of a flange  5  with inter-insertion of an annular gasket  6  in a liquid-tight manner to the drill rod. The upper casing half  4   a  from there extends as an essentially cylindrical hollow body to the lower casing half  4   b . At the end of the upper casing half  4   a  which faces the lower casing half  4   b , a circular shoulder  51  is formed. At this shoulder  51   a  module  30  provided in the lower region of the upper casing half  4   a  adjoins the upper casing half  4   a  by way of a flange  27 . 
     Annular gaskets  36  for sealing the interior and for sealing the connection of the lower casing half  4   b  and the upper casing half  4   a  are accommodated in correspondingly configured grooves  29  (see  FIG. 5 ) against the upper and lower side of the flange  27 . A gasket  35  is inserted into an annular groove  28  provided in the upper region of the module  30  and seals the installation of the module  30  in the upper casing half  4   a  in its upper region. 
     On the upper side of the flange  27  a bore  39  for accommodating a positioning pin  38  is furthermore provided which, in the installed position of the module  30  in the upper casing half  4   a , is partly accommodated in a corresponding bore in the upper casing half  4   a.    
     The module  30  illustrated in  FIGS. 4-7 , as a separate component, includes at its end directed towards the drill rod, four feed apertures  32 ,  37 , each provided staggered by 90° on the circular end of the module  30 . Two mutually opposite feed apertures  32 ,  37  respectively lead to the cutting nozzles  34 , or to the cavity  50  preceding the drill nozzles  41 . 
     Viewed in the direction of flow, the feed apertures  32  constitute the beginning of two flow passages  47  which follow an arcuate course and which terminate at outlet apertures  33  provided ahead of the cutting nozzles  34  provided diametrically on the tool  2 . For fitting the cutting nozzles  34  to the outlet apertures  33 , the module  30  in the region behind the outlet apertures  33 —likewise viewed in the direction of flow—shows a correspondingly configured receiving aperture  49 . The cutting nozzles  34  as such are fitted in corresponding bores  45  in the upper casing  4   a  and are secured by screws  46 . 
     The feed apertures  37 —viewed in the direction of flow—constitute the commencement of two further flow passages  31  which extend separately and mutually opposite towards the cavity  50 . The flow passages  31  in this context have a rounded cross-section which, from the feed apertures  37  to the cavity  50 , first constricts and then extends again. The sectional view illustrated in  FIGS. 3 and 6  in the plane of the cutting nozzles  34  shows the locality of the approximately smallest cross-section of flow passages  31 . 
     Above the module  30  the valve  20  is accommodated rotatably in the upper portion of the casing  4   a . The valve  20  in this context abuts with an annular shoulder  54  on its peripheral surface against a correspondingly configured contact area  52  in the upper portion of the casing  4   a  and is thereby fixed in the direction towards the drill rod (see  FIGS. 8-12 ). 
     At its end, facing towards the module  30 , the valve casing  21  takes the form of a cylindrical hollow body into which is formed a half shell support  8  extending essentially at right angles to the longitudinal axis of the tool  2 . The half shell support  8  includes two oppositely positioned half shells  25  for accommodating valve bodies  26 , the half shells  25  embracing the valve bodies  26  in the upper region in order to secure the positions of the valve bodies  26  in the radial direction of the tool  2 . 
     The valve bodies  26  are of disc-shaped configuration and have mutually opposite spherical surface segments which match the configuration of the feed apertures  32 ,  37 . 
     The half shell support  8  itself is of such configuration that, in a plane transverse to the longitudinal axis of the casing  4 , two mutually opposite regions adjoining the half shells  25  are each opened up in an angular region of about 90° for the flow through the valve  20 . 
     Starting from the half shell support  8  the valve casing  21  includes a circular section of upwardly constricting configuration which is followed by an annular flange  19  of cylindrical configuration, comprising for its connection to a conical gear  22  eight bores  9  designed for accommodating screws  24  extending through the bores  9  into correspondingly formed threads in the conical gear  22 , whereby the latter is firmly connected to the valve casing  21 . 
     The tool  2  illustrated in  FIG. 1  is shown in the operational state “drilling” (drilling situation). In the drilling situation the valve bodies  26  of the valve  20  block the feed apertures  32  of the module  30 . The diameter of the valve body  26  is, in this context, so dimensioned that feed apertures  32  are covered reliably and completely. 
     At the same time, the feed apertures  37  of the module  30  are freely accessible. Water which rushes under high pressure from the drill rod into the tool  2  flows through the interior in the tool  2  above the valve  20  through the latter and through the feed apertures  37  as well as the flow passages  31  following thereon, thereafter passing through the cavity  50  in the lower casing half  4   b  in order to eventually emerge through the bore nozzles  41  into a drum filled with coke, which is not actually illustrated. 
     In order to permit switching from the drilling situation to the operational condition “cutting”, an operating device  10  is provided for operating the valve  20  in the tool  2 . The operating device  10  includes, normal to the axis A extending through the upper casing half  4   a , a shaft  12  at the end of which, positioned inside the tool  2 , a conical gear  11  is provided, which engages the conical gear  22  on the upper side of the valve  20 . At the end opposite to the gear  11  the shaft  12  comprises a tool receiving aperture  13  designed for accommodating a manual lever by means of which the shaft  12  and the conical gear  11  can be turned. The shaft  12  itself is pivotally mounted in a fitting  18 , which is fixed in a bore  17  in the upper casing half  4   a  by means of an annular seal  15  and by screws  14  extending through the fitting  18  into the upper casing half  4   a . Moreover, a further seal  16  seals the shaft  13  in the fitting  18 . 
     For changing from the drilling state to the operational state of “cutting”, the conical gear  11  is actuated by turning the shaft  12  and with the aid of the manual lever fitting the tool receiving aperture  13 . The valve  20  engaging the gear  11  by way of the gear  22  is turned by the gear  11  in the upper casing half  4   a  about the axis A. Jointly with the valve casing  21  the conical gear  22  is rotated and thereby also the valve body  26  of the valve  20 . 
     By turning the valve  20  on the upper end of the module  30 , the valve bodies  26  which previously closed the feed apertures  32  to the flow passages  47  leading to the cutting nozzles  34 , are opened up. When operating the tool receiving aperture  13 , the valve bodies  26  are moved along a circular trajectory by 90° until the feed apertures  37  are totally closed. 
       FIG. 2  shows the tool  2  in the operational state of cutting. Water under high pressure rushes from the drilling rod into the interior of the upper casing half  4   a  and now emerges through the feed apertures  32  into the flow passages  47  and thereafter, through the cutting nozzles  34 . The feed apertures are securely and completely closed by the valve bodies  26  provided there above. The closing action of the valve bodies  26 , in this position as well as during closing the feed apertures  32 , is secured in that the extremely high water pressure which is well in excess of 100 bar, forces the valve bodies  26  into the feed apertures  32 ,  37 .