NOZZLES FOR A FLUID JET DECOKING TOOL

Abstract

A fluid jet nozzle for a decoking tool, a decoking tool and method of operating same. The nozzle includes a nozzle assembly for use in a fluid jet decoking tool. The assembly includes a housing to hold one or more nozzles that are used to spray or otherwise distribute decoking fluid. An internal flowpath that extends from an inlet of the nozzle to an outlet of the nozzle defines a tapered shape such that when the decoking fluid passes through the nozzle, the flowpath produces a predominantly coherent flow pattern in the fluid.

Claims

1. A method of passing a decoking fluid through a nozzle assembly, said method comprising: configuring the nozzle assembly to comprise a housing defining a decoking fluid conduit therein, said housing comprising a cutting nozzle and a drilling nozzle such that said cutting nozzle is fluidly cooperative with at least a portion of said conduit and said drilling nozzle is fluidly cooperative with another portion of said conduit; configuring at least one of the following of said cutting nozzle and said drilling nozzle to define an internal flowpath therein with an inlet, an outlet and a curvilinear tapered shape that converges along an axial length from said inlet to said outlet such that an axial dimension of said flowpath is less than two inches in length and a radial dimension of said flowpath is less than two inches in diameter; and providing said decoking fluid to at least one of the following of said cutting nozzle and said drilling nozzle.

2. The method of claim 1, wherein said drilling nozzle comprises a plurality of drilling nozzles and said cutting nozzle comprises a plurality of cutting nozzles.

3. The method of claim 2, further comprising shifting a flow of said decoking fluid between said plurality of cutting nozzles and said plurality of drilling nozzles.

4. The method of claim 1, further comprising shifting a flow of said decoking fluid between said cutting nozzle and said drilling nozzle.

5. The method of claim 1, wherein said curvilinear tapered shape that converges along an axial length from said inlet to said outlet is defined by an output of a computational fluid dynamics calculation.

6. The method of claim 5, wherein said output of said computational fluid dynamics calculation comprises an output optimized to achieve at least one of minimal radial velocity, minimal axial flow non-uniformity and shortest axial length of said nozzle.

7. The method of claim 1, further comprising reducing any pre-swirl in said decoking fluid prior to having said decoking fluid exit a respective one of said drilling nozzle and said cutting nozzle.

8. The method of claim 1, wherein said axial dimension of said flowpath is less than about 1.8931 inches in length and said radial dimension of said flowpath is less than about 1.68 inches in diameter.

9. The method of claim 1, further comprising operating a shifting apparatus responsive to changes in pressure of a decoking fluid such that in a first operating condition, said shifting apparatus is cooperative with said decoking fluid to establish a drilling mode with drilling nozzle, while in a second operating condition, said shifting apparatus is cooperative with said decoking fluid to establish a cutting mode with said cutting nozzle.

10. The method of claim 1, wherein said housing and said cutting nozzle define a width for said nozzle assembly such that said cutting nozzle increases said width beyond a width of said housing by up to no more than about 10%.

11. The method of claim 1, wherein less than about 15% of a length of said cutting nozzle protrudes laterally beyond an outer dimension of said housing.

12. The method of claim 1, wherein said cutting nozzle is substantially fixed relative to said housing.

13. The method of claim 1, further comprising a flow conditioner chamber formed immediately upstream of said inlet and in fluid communication with said conduit.

14. The method of claim 1, wherein less than about 25% of a length of said drilling nozzle resides outside of said housing.

15. A method of operating a fluid decoking tool, said method comprising: receiving a pressurized decoking fluid from a source; selectively passing said received decoking fluid through a nozzle assembly that forms a part of said decoking tool, said nozzle assembly comprising: a housing defining a decoking fluid conduit therein, said housing comprising a cutting nozzle and a drilling nozzle such that said cutting nozzle is fluidly cooperative with at least a portion of said conduit and said drilling nozzle is fluidly cooperative with another portion of said conduit, wherein at least one of the following of said cutting nozzle and said drilling nozzle defines an internal flowpath therein with an inlet, an outlet and a curvilinear tapered shape that converges along an axial length from said inlet to said outlet such that an axial dimension of said flowpath is less than two inches in length and a radial dimension of said flowpath is less than two inches in diameter; and providing said decoking fluid to at least one of the following of said cutting nozzle and said drilling nozzle.

16. The method of claim 15, wherein said selectively passing said received decoking fluid through a nozzle assembly comprises passing said received decoking fluid through a diverter plate prior to passage of said received decoking fluid through at least one of the following of said cutting nozzle and said drilling nozzle.

17. The method of claim 16, wherein said cutting nozzle is fluidly cooperative with at least a portion of said conduit through said diverter plate and said drilling nozzle is fluidly cooperative with another portion of said conduit through said diverter plate.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The following detailed description of the present invention can be best understood when read in conjunction with the following drawings, where like structure is indicated with like reference numerals and in which:

[0018] FIG. 1 is a cutaway view of a combination coke cutting tool and mode shifting apparatus according to an aspect of the prior art;

[0019] FIG. 2 is a detail view showing the nozzle assembly from the tool of FIG. 1;

[0020] FIG. 3 is a detail view showing an internal flowpath of one of the nozzles from the tool and assembly respectively of FIGS. 1 and 2;

[0021] FIG. 4 is a detail view showing a nozzle assembly according to an aspect of the present invention; and

[0022] FIG. 5 is a detail view showing an internal flowpath of one of the nozzles of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] Referring first to FIG. 1, a conventional decoking tool 1 with protective boring blades or vanes 3 and a mode shifting apparatus 4 installed in the tool 1 is shown. The mode shifting apparatus 4 is made up of numerous components, including a body 4A, actuator sleeve 4B, actuator slot 4C, actuator pin 4D, spring 4E, pressurized fluid inlet 4F, annular hydraulic cylinder 4G, annular piston 4H, actuator pin carrier 41 and a liner sleeve 4J that surrounds a lower portion 6B of a control rod 6 that also includes an upper portion 6A. The control rod 6 is connected to a hydraulic distribution diversion plate (also called diverter plate) 5 such that when the mode shifting apparatus 4 is activated, either manually or by sequentially pressurizing and de-pressurizing operations from a fluid supply (not shown), the control rod 6 rotates the diverter plate 5, causing openings formed through the axial dimension thereof to alternately expose fluid delivery conduit 7 and either the drilling nozzles 10 or cutting nozzles 11 to a supply of high pressure fluid (for example, water) being delivered through an inlet pipe or drill stem 9. In the version depicted in FIG. 1, the drilling nozzles 10 are in fluid communication with the pressurized fluid supply in order to direct a generally downward stream of high pressure fluid into the coke (not shown), thereby boring a hole for the rest of the apparatus 4 to follow. The generally planar disk-like shape of the diverter plate 5, coupled with its rotatable mounting arrangement to control rod 6 permits shifting between a cutting mode and a drilling mode to occur by an intermittent clocking rotation of the diverter plate 5. The details of the construction and operation of diverter plate 5 will not be repeated herein, suffice to say that such details may be found in commonly-owned U.S. Pat. No. 6,644,567.

[0024] Referring with particularity to FIGS. 2 and 3, the drilling nozzles 10 and cutting nozzles 11 of the prior art are shown, where the assembly that includes the nozzles 10 and 11 also include a housing H that defines a radial dimension R and an axial dimension A. As can be seen, the drilling nozzles 10 extend axially a significant distance beyond the axial dimension A, while the cutting nozzles 11 extend radially a significant distance beyond the radial dimension R. Furthermore, these nozzles 10 and 11 are made up of numerous discrete flow tubes or channels that keep their respective fluid streams isolated from one another over a substantial majority of the nozzle length. Cutting nozzle 11 (which has attributes similar to those of drilling nozzle 10) shows in inlet at conditioner 11A and an outlet 11F, as well as the discrete flow channels 11B, 11C and 11D that can be in the form of concentric tubes, clustered soda straws or any other well-known arrangement. As shown, all of the separate flow channels dump the decoking fluid into a common header 11E, and in the process subjects the flow to abrupt angle changes as it makes its way toward the outlet 11F. Such abrupt changes can produce friction, turbulence and other anomalies that may adversely affect the quality of flow being discharged through nozzle 11. These anomalies may be exacerbated by flow separation, such as that which could arise in the discontinuity formed in liner nozzle (also called the nozzle insert) 11G that is formed fluidly upstream of the throat formed where the header 11E meets the outlet 11F. All of these factors may contribute to reductions in the flow's axial component as it exits the nozzle 11 at outlet 11F. Referring with particularity to FIG. 3, the three main parts of the assembly that make up the cutting nozzle 11 are shown, where the conditioner 11A, the liner nozzle 11G and the housing cap 11H are used in conjunction with the flow channels 11B, 11C and 11D, common header 11E and outlet 11F to direct the flow of pressurized water. The liner nozzle 11G collects the flow from the conditioner 11A and accelerates it to the outlet 11F that could be machined to vary the exit area (and flow coefficient) of the nozzle. The housing cap 11H provides a sealed pressure boundary, and additionally aligns the flow conditioner 11A and erosion-resistant nozzle insert 11G.

[0025] Referring next to FIGS. 4 and 5, features associated with an assembly 100 and the nozzles 110, 111 of the present invention are disclosed. The assembly 100 includes housing H that includes conduit 107A, 107B that act as fluid passageways to deliver decoking fluid that comes from a pressurized source (not shown) to the drilling nozzles 110 and cutting nozzles 111. Referring with particularity to FIG. 5, a cutting nozzle 111 is shown, although it will be appreciated that the structure and flowpath depicted therein is equally applicable to the drilling nozzle 110. Unlike the conventional flowpath depicted in FIG. 3, the internal surface of FIG. 5 may define a generally tapered converging shape 111A that is optimally-shaped for decoking fluid jet spraying, and was achieved using a CFD calculation to achieve minimal radial velocity, minimal non-uniformity in the axial flow, in the shortest nozzle length possible. The present inventors have discovered that by optimizing the nozzles in the manner shown for coke cutting operations, a more columnar, coherent flow is produced, as the radial components of the flow velocity are minimized. By such improvements in flowpath tailoring, the size of the nozzles 110, 111 relative to nozzles 10, 11 of FIGS. 2 and 3 (particularly, their axial dimension) can be reduced, while still providing the necessary jet impact force and jet coherence. Such size reduction (as well as part number reduction) improves manufacturability, and allows for simpler drilling due in part to the smaller bore profile. The present inventors have employed CFD modelling and bench testing as a way to optimize the internal flowpath shape 111A based upon the particular needs of the decoking tool and its environment. By reducing or preventing stagnant areas and large eddy flows, the nozzle flowpath can preserve a high degree of flow coherence.

[0026] Referring with particularity to FIG. 5 in conjunction with the data of Table 1, views and dimensions of internal water flowpaths for the cutting nozzle 111 is also shown. It will be appreciated that the features discussed below for cutting nozzle 111 are equally applicable to drilling nozzle 110, and therefore will not be repeated. Table 1 below shows the representative X and Y dimensions of the internal flowpath surface of a nozzle made in conjunction with the present invention where a CFD algorithm was employed:

TABLE-US-00001 TABLE 1 NOZZLE DIMENSIONS X (inches) Y (inches) 0.0000 0.8400 0.0169 0.8389 0.0317 0.8351 0.0442 0.8297 0.0549 0.8235 0.0640 0.8172 0.0720 0.8110 0.0791 0.8051 0.0856 0.7996 0.0916 0.7946 0.0972 0.7899 0.1025 0.7856 0.1077 0.7817 0.1128 0.7781 0.1179 0.7748 0.1231 0.7718 0.1283 0.7687 0.1338 0.7655 0.1402 0.7619 0.1473 0.7578 0.1552 0.7534 0.1639 0.7485 0.1735 0.7433 0.1840 0.7376 0.1954 0.7315 0.2077 0.7250 0.2210- 0.7181 0.2353 0.7107 0.2506 0.7030 0.2669 0.6948 0.2842 0.5863 0.3026 0.6774 0.3220 0.6681 0.3424 0.6585 0.3640 0.6485 0. 3865 0.6382 0.4102 0.6276 0.4348 0.6167 0.4605 0.6056 0.4871 0.5943 0.5148 0.5826 0.5433 0.5712 0.5728 0.5594 0.6032 0.5475 0.6344 0.5356 0.6663 0.5237 0.6990 0.5118 0.7324 0.4999 0.7663 0.4882 0.8009 0.4765 0.8359 0.4651 0.8713 0.4538 0.9071 0.4428 0.9432 0.4320 0.9794 0.4216 1.0158 0.4114 1.0523 0.4016 1.0888 0.3922 1.1252 0.3631 1.1514 0.3744 1.1974 0.3662 1.2331 0.3583 1.2884 0.3510 1.3034 0.3440 1.3378 0.3374 1.3718 0.3313 1.4051 0.3257 1.4379 0.3204 1.4699 0.3156 1.5012 0.3111 1.5318 0.3071 1.5617 0.3034 1.5907 0.3001 1.6189 0.2971 1.6462 0.2944 1.6727 0.2921 1.6983 0.2900 1.7230 0.2882 1.7469 0.2867 1.7698 0.2854 1.7919 0.2843 1.8131 0.2834 1.8331 0.2826 1.8478 0.2822 1.8592 0.2819 1.8684 0.2817 1.8760 0.2815 1.8824 0.2814 1.8881 0.2813 1.8931 0.2813

[0027] By reducing the pressure drop associated with a conventional nozzle, nozzles 110, 111 made according to the present invention provide a shorter axial dimension and related smaller footprint for nozzle assembly 100, allowing the nozzle to fit within tight confines. For example, during situations where a collapsed bed occurs, the new smaller nozzle assembly 100 is primarily recessed back into the assembly 100 resulting in a more streamlined shape that can often be directly pulled out of a collapsed bed. In addition, such a configuration can save energy and potentially allow the use of a smaller pump and motor, as the same fluid volume and velocity at the exit of nozzles 110, 111 can be achieved with less pumping. Furthermore, the new nozzle assembly 100 consists of two smaller pieces with simpler and less costly manufacturing.

[0028] CFD and related flow simulation algorithms, as well as bench testing can be used to provide preferred decoking fluid flowpath shapes. It will be appreciated by those skilled in the art that an underlying CFD package may be developed specifically for the present application, or an off-the-shelf commercial code can be used to perform the CFD analyses discussed herein. CFD modelling can be used to demonstrate particular flow attributes, such as coherent flow, laminar or turbulent flow, locations where separated flow can be expected, or the like. In particular, CFD can be used to model particular nozzle internal profiles (i.e., flowpaths), such as the unique profile associated with the nozzles of the present invention. Such computational methods can take into consideration particular hydraulic attributes of the decoking fluid. Iterative approaches may also be employed to study the effects of flow perturbation and internal flowpath shape optimization. Such iterations could be based on simple starting geometries (such as tubular members, simple cones and other easily-defined configurations) that could then be modified to produce desirable flow attributes (such as a linear pressure drop along the flow axis). The optimization parameters may include minimizing the radial inflow at the exit throat of the nozzle and the standard deviation of the axial flow velocity (achieving thereby uniform flow across the exit throat). An additional benefit is that the resulting geometry can use well known similarity laws to allow scaling, depending on the size needs of the assembly 100. Hence, nozzles can be made for a variety of flows and pressures within the limits proscribed by fully developed turbulent flow the importance of which is that it allows for the linear conversion of kinetic and pressure energy, thereby making it easier to ensure accurate prediction of scaled designs.

[0029] While certain representative embodiments and details have been shown for purposes of illustrating the invention, it will be apparent to those skilled in the art that various changes may be made without departing from the scope of the invention, which is defined in the appended claims.