US 3136723 A
Description (OCR text may contain errors)
June 9, 1964 R. W. ERWIN ETAL HYDROCYCLONES Filed Feb. 2'7, 1959 Ceramic liner Awe/272115" fiansome Erwin Kit/lard U'Jhie/z/s United States Patent 3,136,723 HYDROCYCLONES Ransorne W, Erwin and Richard L. OShields, Fort Worth, Tex., assignors to Bass Brothers Enterprises, Inc., Fort Worth, Tern, a corporation of Texas Filed Feb. 27, 1959, Ser. No. 796,151 2 Claims. (Cl. 210--512) This invention relates to new and useful improvements in so called hydrocyclones of the type used in the oil Well drilling art for the purpose of separating sand from drilling mud or slurry, and in particular the invention relates to an improved underflow nozzle for such hydrocyclones.
A conventional hydrocyclone, for example such as is disclosed in United States Patent No. 2,816,658, issued December 17, 1957 to R. T. Braun et al., consists of a vertically elongated housing provided adjacent the top thereof with a conduit receiving drilling mud or slurry under pressure, the housing containing a set of liners providing a frusto-conical chamber which terminates at its lower, relatively small end in an underflow nozzle through which particles of sand are ejected as the result of downward spiraling flow and centrifugal force in the passage of mud through the chamber, while de-sanded mud travels centrally upwardly through the chamber and is discharged through an overflow at the top of the housing. The aforementioned chamber forming liners are made of material such as molded rubber which possesses reasonably good Wear resistant properties in the presence of abrasive action of the sand, when the apparatus is used in certain locations where sand particles are rounded and substantially free from sharp edges or points. However, in other locations where sharp edged or sharp pointed sand particles exist, the abrasive action thereof on the liners is so pronounced that the liners become Worn out after only a few days of use and must be replaced.
As already noted, the drilling mud or slurry delivered into the hydrocyclone chamber under pressure follows a downwardly spiraling path in which the velocity of the mud' is progressively increased by the progressively decreasing diameter of the frusto-conical chamber, until a maximum velocity is attained in the underflow or sand outlet nozzle itself. Since the abrasive action of the sand particles increases with the velocity of the mud, the effect of abrasion is greatest in the underflow nozzle and the latter is usually the first to become damaged thereby. However, once the underflow nozzle becomes worn by the effects of abrasion, the wear progresses upwardly in the chamber until all the liners are damaged.
Accordingly, the principal object of the invention is to materially prolong the useful life of hydrocyclone liners, particularly under deleterious conditions created by highly abrasive particles of sand. This object is attained by the provision of an improved underflow nozzle which effectively resists the abrasive action and, by remaining unaffected by wear for substantial periods of time, prevents or greatly reduces the possibility of damage by wear from spreading to the molded rubber liners in the hydrocyclone chamber above the underflow nozzle.
Another important feature of the invention resides in forming the improved underflow nozzle in such manner that an annular step exists at the junction of the nozzle with the overlying molded rubber liner, which step, while not interfering with the downward spiraling flow of mud, effectively assists in preventing damage by abrasive wear from spreading from the nozzle into the overlying liner.
Some of the advantages of the invention reside in its simplicity of construction, in its efficient operation, in its adaptability to economical manufacture, and in its adaptability for use in hydrocyclones of various sizes and types.
With the foregoing more important objects and features FIGURE 3 is a top plan View of the underflow nozzle per se.
Referring now to the accompanying drawings in detail, the general reference numeral 10 designates a conventional hydrocyclone such as is disclosed in the aforementioned patent No. 2,816,658, although it is to be under:
stood that the use of the invention is by no means limited to this particular hydrocyclone and that the invention may be used with other hydrocyclones of various sizes and types.
' In any event, for. illustrative purposes, the hydrocyclone 10 embodies a vertically elongated housing 11 provided adjacent its upper end with a conduit 12 for receiving drilling mud or slurry under pressure, the housing containing a plurality of molded rubber liners, two of which are shown at 13 and 14. To prevent lateral shifting, the liners are interfitted as indicated at 15, and provided under the liner 14 is an underflow nozzle or valve, designated generally by the reference numeral 17, which is held assembled to the housing 11 by aring 18 and bolts 19. The liners 13, 14 and the nozzle 17 *coact to form a frusto-conical chamber 20, wherein drilling mud delivered under pressure through the conduit 12 follows a downward spiraling path with progressively increasing velocity which reaches its maximum at the relatively small, lower end of the chamber wherein particles of sand, driven against the walls of the chamber by centrifugal force, are ejected through an outlet opening 21 in the nozzle17, whilede -sanded mud travels centrally upwardly through the chamber and is discharged through;
an overflow nozzle 22 at the top of the housing 11. Apart from the underflow nozzle 17, the arrangement and operation of the hydrocyclone are conventional and require no further description herein.
In accordance with conventional practice, the nozzle 17, like the liners 13, 14, is made of molded rubber and is subjected to the abrasive action of sand particles which is most pronounced in the region of greatest mud velocity adjacent the outlet opening 21. Thus, if the sand particles are sharp edged or sharp pointed rather than round or smooth, their abrasive action is so great that the nozzle wears out quickly and prematurely. Moreover, once the nozzle is damaged by wear, the damage spreads quickly upwardly in the chamber 20, until all the liners in the chamber are worn.
The invention eliminates this disadvantage by the provision of the nozzle 17 which embodies in its construction a substantially tubular metallic shell 25, having a ceramic liner or insert 26 cemented therein. The shell is somewhat longer than the liner, so that the downwardly projecting portion of the shell, below the lower end of the liner constitutes a guard 25a for preventing ejected sand particles from spreading too far laterally. The liner 26 is provided at-its upper end with an outturned, annular flange which is seated in a counterbore formed in the upper end of the shell as indicated at 27, and the upper end of the shell itself is formed with an outturned, annular flange 25b for clamping the entire nozzle 17 to the housing 11 by the aforementioned ring 18 and bolts 19, as will be clearly apparent.
The top face of the flange 25b of the shell 25 is provided with a V-shaped annular groove 28 to receive a V- shaped annular projection formed at the lower face of the overlying liner 14 and thereby prevent any lateral displacement of the liner 14 relative to the nozzle 17.
It is to be particularly noted that the inside diameter of the liner 26 at its upper end is somewhat greater than the inside diameter of the liner 14 at its lower end, so that an annular step or shoulder 29 exists at the junction of the upper face of the liner 26 with the lower face of the liner 14. The orientation of this annular step is so that the step does not interfere with the downward spiraling flow of drilling mud in the chamber 20, but it does present an obstacle to any abrasive action and wear spreading from the nozzle 17 upwardly into the chamber 20, so as to safeguard the rubber liners 13, 14, against injury.
The material of the ceramic liner 26 is of particular importance, the same being fired with a very smooth surface and possessing a remarkable quality of hardness, so that it is virtually unaffected by wear from the abrasive action of sand particles to which it is subjected. Thus, in the virtual absence of Wear in the liner 26 and with the annular step 29 acting to effectively resist spreading of wear upwardly from the nozzle 17, the rubber liners 13, 14 of the hydrocyclone are safeguarded against premature wear, even under conditions of most pronounced abrasive action of sharp edged and pointed sand particles.
While in the foregoing there has been described and shown the preferred embodiment of the invention, various modifications may become apparent to those skilled in the art to which the invention relates. Accordingly, it is not desired to limit the invention to this disclosure and various modifications may be resorted to, such as may lie within the spirit and scope of the appended claims.
What is claimed as new is:
1. In a hydrocyclone, the combination of a vertically elongated housing, liner means of rubber-like material provided in said housing and forming therein a frustoconical chamber having its minor end at the bottom of the housing, and an underflow nozzle including a ceramic member provided at the bottom of said housing, said ceramic member being formed with a frusto-conical chamber portion constituting a downward continuation of the housing liner chamber and terminating at its lower end in a discharge opening wherein the upper end of said frusto-conical chamber portion in said ceramic member is of a larger diameter than the lower end of said chamber in said rubber liner means, whereby to provide an annular shoulder at the junction of said ceramic member with said rubber liner means.
2. In a hydrocyclone, the combination of a vertically elongated housing, liner means of rubber-like material provided in said housing and forming therein a frustoconical chamber having its minor end at the bottom of the housing, an underllow nozzle comprising a tubular metallic shell removably attached at its upper end to the bottom of said housing and extending downwardly therefrom in axial alignment with said chamber, a ceramic member removably positioned in said shell and provided with a frusto-conical chamber portion, said chamber portion constituting a downward continuation of the chamber in said rubber liner means and terminating at the lower end of the ceramic member in a discharge opening, the lower end portion of said shell projecting below the lower end of said ceramic member and providing a tubular guard below said discharge opening, the upper end of said ceramic member being in abutment with the lower end of said rubber liner means, the upper end of said chamber portion in said ceramic member being of a greater diameter than the lower end of the chamber in the rubber liner means whereby to provide an annular shoulder at the junction of the ceramic member with said rubber liner means, said annular shoulder facing the chamber portion in said ceramic member, and said ceramic member having a higher resistance to wear by abrasion than said rubber liner means.
References Cited in the file of this patent UNITED STATES PATENTS 2,377,524 Samson et al June 5, 1945 2,816,658 Braun et al. Dec. 17, 1958 FOREIGN PATENTS 712,792 Great Britain July 28, 1954 OTHER REFERENCES Bulletin No. 2503 The fr Dorrclone, Dorr-Oliver, Inc., Stamford, Conn, 1955.
Leaflet No. 2505 The P-SO Dorrclone, Dorr-Oliver Inc, Stamford, Conn, 1956.