WO2001097978A1

WO2001097978A1 - Nozzle apparatus and process for cleaning interior surface of pipes using same

Info

Publication number: WO2001097978A1
Application number: PCT/US2001/019064
Authority: WO
Inventors: Michael Scott Leonard; Vincent Monroe Salyer; Carl Lynn Taylor; Jacob Anthony Southerland
Original assignee: Eastman Chemical Company
Priority date: 2000-06-19
Filing date: 2001-06-14
Publication date: 2001-12-27

Abstract

A nozzle assembly (10) for directing a fluidized particulate stream from a supply source includes a cylindrical conduit having an exterior wall surface, (14) a first opening with a coupling device for affixing the nozzle assembly to the fluidized particulate supply source a discharge opening positioned downstream from the first opening and an internal wall surface (20) which defines a flow channel through which the fluidized particulate stream flows. The nozzle has a retaining device (22) affixed to a surface of the conduit and an adjustable directing device (42) positioned proximate to the discharge opening for directing at least a portion of the fluidized particulate stream radially outward. A threaded connecting rod (34) affixes the directing device to the retaining device so that the directing device may be adjustably positioned relative to the discharge opening. The nozzle assembly is particularly useful in blast cleaning the interior of a pipe.

Description

NOZZLE APPARATUS AND PROCESS FOR CLEANING INTERIOR SURFACE OF PIPES USING SAME

BACKGROUND OF THE INVENTION

Field of the Invention:

The present invention relates to a nozzle apparatus and more particularly, to a nozzle assembly for directing a fluidized particulate stream. The nozzle assembly is useful in cleaning the interior surface of pipes and particularly useful in cleaning pipes that transport high purity polymers and are in service for food grade materials. Another aspect of the present invention is a method for cleaning the interior surface of a pipe using the nozzle assembly of the present invention.

Background of the Invention:

There are many reasons why it is frequently necessary to clean the inner periphery of piping. For example, it may be necessary to remove scale, rust, paint, polymeric deposits and the like that have accumulated within the pipe due to periods of non-use, extended use or change of service and materials that are to be transported. Such deposits can cause reduced flow rates and/or product contamination. Considering the fact that most pipe sections are relatively long it is extremely difficult to clean the interior surfaces. Adding to this physical problem is the concern that any cleaning method used must not affect the material being transported within the pipe once the pipe is placed back into service. High purity polymer and food grade material applications are especially sensitive to any foreign particulate matter.

There are devices available today for moving longitudinally through the interior of pipe and which eject a cleaning material radially outward. One such device is nozzle for high pressure water. Typically, water under pressure of several thousand pounds per square inch is fed through the pipe where the pressure removes the deposits. For example, U.S. Pat. No. 5,096,122 issued on March 17, 1992 to Abramoska discloses a rotatable high pressure spray nozzle having: a) a body with a central axis, an axial bore adapted to be connected to a tubular conduit for high pressure water, a counterbore, a tubular stem portion through which the counterbore extends, and at least one port extending through the stem portion from the counterbore to the exterior of the body; (b) an annular rotor surrounding the stem portion, the rotor having therein a bore which is in close proximity with the exterior of the stem portion, an annular channel in communication with the at least one port, flow restrictor means extending into the channel and rotating with the rotor for periodically obstructing the flow of water through at least the one port into said channel as the rotor rotates, and a plurality of orifices extending through the rotor from the channel to the exterior of the rotor for discharging high pressure water, the orifices being arranged so as to cause self-rotation of said rotor; and (c) means for restraining the rotor from axial movement and for closing the end of the counterbore which is remote from said bore. However, it has been discovered that a disadvantage of high pressure water cleaning is that the nozzle has a tendency to whip inside the pipe causing detrimental effects to the sides of the pipe which may further lead to product contamination when pieces of pipe metal enter the process material.

Another approach is to use abrasive blasting. Abrasive blast cleaning is a century- old process that has seen few changes in the underlying technology since its inception. The traditional approach uses high pressure air to accelerate solid abrasive particles such as sand or steel grit to high speeds, which then impact the surface being cleaned. U.S. Pat. No. 4,845,903 issued on July 11, 1989 to Woodward discloses a sand blasting device having a first conduit for the conveyance of abrasive particles to a first outlet end and a second parallel conduit for the conveyance of a pressurized fluid to a second outlet end. The device includes a terminal support having housings wherein the outlet ends of the conduits are respectively secured; a first passage coaxial to the first conduit for a direct outlet of the abrasive particles from the support; a second passage coaxial to the second conduit for an outlet of the fluid from the second conduit and a projection integral with the support in front of the second passage. The projection has a flat external surface located near the first passage and has a cylindrical cavity communicating the second passage with a port on the external surface. The axis of the cavity is perpendicular to the surface and is inclined in such a way that it meets the axis of the first conduit at an angle. A nozzle has an axial hole and a transverse groove machined across said hole at an outlet end of the nozzle, for forming a jet of pressurized fluid ejected in a fan-like spray. The nozzle is coaxially mounted into the cavity so that the jet of abrasive particles coming from the first conduit is thrown against a surface to be cleaned at an angle controlled by the inclination of the axis of the nozzle and in the form of a jet having a transverse lenticular cross-section.

Recently, abrasive blasting has included sublimable particles. For example, U.S. Pat. No. 5,109,636 issued on May 5, 1992 to Lloyd et al. discloses a particle blast cleaning apparatus which uses sublimable pellets as the particulate media. The apparatus includes a housing means having sublimable pellet receiving and discharge stations and a radial pellet feeder means for transporting the pellets from the receiving station to the discharge station. The feeder means includes a rotor having one or more transport cavities disposed in the circumference of the rotor to receive the pellets for radial transport between the stations. The apparatus further includes a means for providing mechanically assisted flow of the pellets to the transport cavities at the receiving station, a discharge nozzle, and a means for supplying a pressurized transport gas adjacent the discharge station for conveying the pellets leaving the discharge station to the discharge nozzle. U.S. Pat. No. 5,690,543 issued on November 25, 1997 to Curran discloses a blasting nozzle assembly for blast cleaning internal pipe surfaces. The nozzle includes: a) a cylindrical sleeve having a given length and a central axis. The sleeve defines a flow channel through which the blasting abrasive and a carrier fluid can flow in a given flow direction. The web has a member integrally formed within the sleeve and extending across the diameter of the flow channel. The web member has a length that is at least 60 % of the given length of the sleeve. The web member further has an opening therein which extends coaxially with the axis of the sleeve. A stem is inserted into the opening of the web member, and extends coaxially with the sleeve and has a free end protruding from the sleeve. A deflection tip is mounted on the free end of the stem for radially deflecting the blasting abrasive and the carrier fluid flowing in the given flow direction.

A problem with the aforementioned nozzles is the inability to adjust the spray and its pattern. Accordingly, there is a need for a nozzle assembly that will accommodate adjusting a fluidized particulate stream for abrasive cleaning the inside of a pipe. SUMMARY OF THE INVENTION

Broadly, the present invention is a nozzle assembly which is useful for abrasive cleaning internal pipe surfaces. The nozzle includes: a) a cylindrical conduit having an exterior wall surface, a first opening with a coupling means for affixing the nozzle to the fluidized particulate supply source, a second, discharge opening distally positioned downstream from the first opening and an internal wall surface defining a flow channel through which the fluidized particulate stream flows; b) a retaining means nonrotatably secured to at least one surface of the conduit; c) an adjustable directing means positioned proximate to the discharge opening for directing at least a portion of the fluidized particulate stream radially outward; and d) connecting means for affixing the directing means to the retaining means.

In accordance with another aspect of the present invention, a method is for cleaning the interior wall surface of a pipe provided. The method includes contacting the interior wall surface with a fluidized particulate stream injected into the pipe through the nozzle assembly of the present invention.

It is an object of the present invention to provide an internal pipe cleaning nozzle assembly which provides for an adjustable spray and which overcomes the disadvantages of the aforementioned devices. It is another object of the present invention to provide a method for internally cleaning a pipe

These and other objects and advantages of the present invention will become more apparent to those skilled in the art in view of the following description and the accompanying drawings wherein like parts and objects have similar reference numerals. It is to be understood that the inventive concept is not to be considered limited to the constructions disclosed herein but instead by the scope of the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded cross-sectional view of the nozzle assembly of the present invention. FIG. 2 is a cross-sectional view of another embodiment of the nozzle assembly of the present invention.

FIG. 3 is a discharge end longitudinal axis elevation view of FIG. 2.

FIG. 4 is an exploded cross-sectional view of the nozzle assembly of FIG. 2.

FIG. 5 is an elevational axial view the inside illustrating the inside of the cylindrical conduit and an alternative embodiment for affixing the retaining means inside the assembly.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to the figures of drawings in detail, and with particular reference to FIGS.

1 - 4, an improved nozzle assembly 10 of the present invention is illustrated. As can be seen from FIG. 1, the components of the nozzle assembly 10 are substantially coaxially aligned along a longitudinal axis A. The nozzle assembly 10 has an annular body which provides a cylindrical conduit 12 through which an air and abrasive mixture is channeled. The cylindrical conduit 12 includes an exterior wall surface 14, a first opening 16, and positioned adjacent to the first opening 16, a coupling means 17 for removably attaching the nozzle to a fluidized particulate stream hose, piping, or other transport device, a second opening 18 for discharging the fluidized particulate stream and an interior surface 20. The coupling means 17 can be any known type of mating coupling device known to those skilled in the art, such as pneumatic couplings, cam locking devices and particularly preferred coupling means are threads. The threads 17 can be either male or female, that is, the threads can be formed on either the exterior wall surface 14 (male) or on the interior wall surface 20 (female). The coupling means 17 permits the nozzle assembly 10 to be connected, and preferably screwed, to its respective mating connection on the conduit supplying the pressurized fluidized particulate stream, not shown.

A retaining means 22 is nonrotatably affixed and preferably, immovably affixed to at least one surface of the conduit 12, and preferably it is affixed to the interior surface 20. The retaining means 22 includes a rigid member 24 having opposing first and second ends 26 and 28, respectively. The member 24 transversely extends across the diameter of the conduit 12. As used herein, the term "transverse" or "transversely" means a direction that is substantially perpendicular to the fluidized particle stream longitudinal flow direction. The member 24 has a length, defined as the distance between the two ends 26 and 28, that can be less than, approximately equal to, or greater than the interior diameter of the conduit 12. In the case where the length of the member 24 is less than the interior diameter of the conduit 12, as it will be more fully described and understood below, the member 24 will have to be welded or otherwise immobilized and desirably, nonrotatably affixed to the interior surface 20 for the nozzle assembly 10 of the present invention to function properly. At least one end 26 or 28 and preferably both ends 26 and 28 of the retaining member 24 are affixed to the interior surface 20 by welding, soldering, screwing, brading, brazing, pressure fitting, and the like.

Alternatively, the retaining member 24 can have a length that is greater than the interior diameter of the conduit 12. As seen in FIG. 1, the member 24 has a predetermined length sufficient for the ends 26 and 28 to be inserted through substantially aligned, opposing openings in the exterior wall surface 14. The ends 26 and 28 can then be welded, brazed, riveted or otherwise affixed using means known in the art to fasten the member 24 to the conduit 12. Although not shown, but within the scope of the present invention, one will understand and recognize from the description herein that in the place of having two substantially aligned, opposing openings in the exterior wall surface 14, only one opening in the exterior wall 14 would be necessary for inserting the member 24, with an opposing, substantially aligned well or indention in the interior wall 20 for seating one end, for example end 26, of the retaining member 24 on the interior surface 20 with the other end, for example 28, being immovably affixed as described above. Referring to FIG. 5, another embodiment for affixing the member 24 is shown wherein the conduit 12 includes opposing, substantially coaxially aligned channels 30 and 31 into which ends 26 and 28, respectively, are inserted. The channels 30 and 31 have a predetermined length that will allow the member 24 to be positioned within the conduit 12 for proper function of the nozzle assembly 10. Accordingly, the channels 30 and 31 can have a length ranging from about 5 % to about 95 % of the length of the conduit 12.

Referring again to FIGS. 1-4, the width of the member 24 is comparatively small relative to the length of the conduit 12 and desirably is less than about 50 % of the length of the conduit 12. More desirably, the width of the member 24 is less than about 40 %, preferably less than about 25 %, more preferably less than about 15 % and most preferably is from about 2 to about 10 % of the length of the conduit 12. Advantageously, the relatively small width of the member 24 does not interfere with the flow of the fluidized particle stream and has the advantage of less wear comparative to one that has a cross member that is greater than about 50 % of the length of the conduit 12. The member 24 includes a substantially center first bore opening 32 sized to engage a connecting means 34. As shown, the connecting means 34 is a continuous threaded rod having a first end 36 and a second end 38. The first bore opening 32 is shown having a set of engaging female threads for securing the first end 36 of to the retaining member 24. Optionally, the first bore 32 can be smooth with a diameter large enough for the connecting rod 34 to be inserted through the bore 32 which is then securely affixed to the retaining member 24 by use of a fastener, such as nut, rivet, weld or other means, as is shown in FIG. 2. Preferably, the connecting rod 34 is affixed to the retaining member 24 by threading the connecting rod 34 into the first bore 32 and/or inserting the connecting rod 34 through the bore 32 and adjustably affixing the connecting rod 34 to the retaining member 24 by use of a nut.

The second end 38 of the connecting rod 34 is adapted to be affixed to a second bore 40 in a fluid directing means 42. The second bore 40 is positioned substantially in the center of and along the longitudinal axis the fluid directing means 42. The second bore 40 can extend partially into or through the fluid directing means 42 and can include a set of female threads for engaging the connecting rod 34. Alternatively, the second bore 40 can be smooth with a diameter large enough for the second end 38 of the connecting rod 34 to be inserted through the second bore 32 which is then securely affixed to the fluid directing means 42 by use of a fastener, such as nut, rivet, weld or other means, as is shown in FIG. 2. In another embodiment of the present invention, the second bore 40 extends through the fluid directing means 42 and includes a set of engaging threads so that a locking member, such as a nut, can be secured to the second end 38 thereby adjustably affixing the fluid directing means 42 to the connecting rod 34.

The fluid directing means 42 has an upstream end 44, positioned proximate to the second opening 18, i.e., the discharge opening of the conduit 12, and a distally positioned downstream end 46. The fluid directing means 42 includes an angled fluid contacting surface 48 which directs at least a portion of the exiting, coaxially flowing, fluidized particulate stream radially outward toward the interior pipe wall. The angle, θ, of the fluid contacting surface 48 is generally determined by the difference in radii of the upstream end 44 and the downstream end 46 and can be from about 5 degrees to about 65 degrees, and preferably, is from about 5 degrees to about 50 degrees. More preferably, the angle, θ, of the fluid contacting surface 48 is from about 10 degrees to about 45 degrees and most preferably is from about 10 degrees to about 30 degrees. Although the angled fluid contacting surface 48 is shown as a substantially linear surface one skilled in the art will understand that the surface 48 can be arcuate. For the purpose of clarity of description, a shoulder on the upstream end 44 of the fluid directing means 42 has been illustrated. However, one skilled in the art will recognize that a smooth interface of the connecting rod 34 at the upstream end 44 is desirable to facilitate a flowing direction transition in the fluidized particulate stream and to minimize wear to the directing means 42.

It is desirable that the interior wall surface 20 proximate to the second opening 18 have a second angle, β, that is from about 5 degrees to about 65 degrees, and preferably, is from about 5 degrees to about 50 degrees. More preferably, the second angle, β, is from about 10 degrees to about 45 degrees and most preferably is from about 10 degrees to about 30 degrees. In an especially preferred embodiment, the second angle, β, is substantially equal to the angle θ of the fluid contacting surface 48. The angles of θ and β may vary independently based on the particular use to which the nozzle assembly 10 is intended, piping size, the physical properties of the particulate matter, and the outer diameter of the nozzle assembly.

In another embodiment of the present invention, the connecting rod 34 includes a third bore 50 extending the length of the rod 34, i.e., from the first end 36 through to the second end 38 and which defines a second fluid flow channel. This embodiment facilitates a multi-directional fluidized particulate stream wherein a portion of the coaxial stream is vectored toward the interior wall surface and the remaining portion is directed forward. This, advantageously, permits the cleaning of bends in the piping, such as 45 and 90° bends. The nozzle assembly 10 and the parts described thereof are preferably constructed of stainless steel in order to assure long life.

An unexpected advantage of the present invention is the simplicity by which a user may substantially adjust both the fluidized particulate stream direction and flow rate to suit the intended use. For example, the fluidized particulate stream direction and flow rate may be adjusted by rotating the fluid directing means 42 longitudinally along the connecting rod 34, or as shown in the embodiment of FIG. 1, by rotating the connecting rod 34, or by rotating both the fluid directing means 42 and the connecting rod 34 as shown in FIGS. 2 and 4.

Another advantage of the present invention is that a plurality of fluid directing means 42 may be utilized on the same connecting rod 34 wherein each fluid directing means 42 has a different angled contact surface 48.

Another advantage of the present invention is that it the nozzle assembly 10 may be used in a variety of pipe sizes wherein the ratio of the inside pipe diameter to the outside diameter of the nozzle assembly is from about 1.1 to about 6 and more preferably from about 1.1 to about 3.

In use, the interior of a pipe is cleaned by contacting the interior pipe surface with a fluidized particulate stream that is injected into the pipe using the nozzle assembly of the present invention. The particulate component of the fluid stream can be conventional ice and sand blasting materials but a particularly preferred material is sodium bicarbonate, such as ARMEX available from Arm and Hammer. Having described the invention in detail, those skilled in the art will appreciate that modifications may be made to the various aspects of the invention without departing from the scope and spirit of the invention disclosed and described herein. It is, therefore, not intended that the scope of the invention be limited to the specific embodiments illustrated and described but rather it is intended that the scope of the present invention be determined by the appended claims and their equivalents.

Claims

CLAIMS We claim:

1. A nozzle assembly for directing a fluidized particulate stream from a supply source, said nozzle comprising: a. a cylindrical conduit having an exterior wall surface, a first opening with a coupling means for affixing said nozzle to said fluidized particulate supply source, a second, discharge opening distally positioned downstream from said first opening and an internal wall surface defining a flow channel through which said fluidized particulate stream flows; b. a retaining means affixed to a surface of said conduit; c. an adjustable directing means positioned proximate to said discharge opening for directing at least a portion of said fluidized particulate stream radially outward; and d. connecting means for affixing said directing means to said retaining means.

2. The nozzle assembly of claim 1 wherein said coupling means is selected from the group consisting of mating threads, pneumatic pressure couplings, and cam lock couplings. Please give other suitable type of connections that may be used. Not concerned with safety issues just types of connections.

3. The nozzle assembly of claim 2 wherein said coupling means is a thread.

4. The nozzle assembly of claim 3 wherein said mating thread is cut into the exterior wall surface.

5. The nozzle assembly of claim 3 wherein said mating thread is cut into the interior wall surface.

6. The nozzle assembly of claim 1 wherein said retaining means is immovably affixed to said cylindrical conduit.

7. The nozzle assembly of claim 1 wherein said retaining means includes a member extending transversely relative to a flow direction of said fluidized particulate stream inside of said conduit and wherein said member includes a first end, a second end and a first substantially central bore opening through which said connecting means is inserted.

8. The nozzle assembly of claim 7 wherein said transversely extending member is extends through an opening in said interior and exterior walls and is immovably affixed to said exterior wall.

9. The nozzle assembly of claim 8 wherein said transversely extending member is non-rotatably affixed to said interior surface.

10. The nozzle assembly of claim 9 wherein said interior wall surface includes opposing channels formed therein and said transversely extending member has a length that is defined by the distance between said first and second ends that is . greater than an inside diameter of said cylindrical conduit wherein the said ends are matingly inserted into said opposing channels.

11. The nozzle assembly of claim 7 wherein said first bore opening includes a set of internal threads

12. The nozzle assembly of claim 11 wherein said connecting means is a rod having external threads that mating correspond to said internal threads of said first bore opening.

13. The nozzle assembly of claim 12 wherein said rod includes a central through extending channel.

14. The nozzle assembly of claim 1 wherein said adjustable directing means includes an angled fluidized particulate stream contacting surface.

15. The nozzle assembly of claim 14 wherein said angle is from about 5 to about 65 degrees.

16. The nozzle assembly of claim 14 wherein said angle is from about 5 to about 50 degrees.

17. The nozzle assembly of claim 14 wherein said angle is from about 10 to about 45 degrees.

18. The nozzle assembly of claim 14 wherein said angle is from about 10 to about 30 degrees.

19. The nozzle assembly of claim 12 wherein said directing means includes a second substantially central longitudinal bore which includes a set of threads for mating with said connecting means.

20. The nozzle assembly of claim 19 wherein said second longitudinal bore extends through said directing means and wherein said directing means is adjusted relative to said discharge opening by rotating said directing means on said threaded connecting means. 5

21. The nozzle assembly of claim 19 wherein said second longitudinal bore extends through said directing means and wherein said directing means is adjusted relative to said discharge opening by rotating said threaded connecting means.

22. The nozzle assembly of claim 19 wherein said second longitudinal bore extends through said directing means and wherein said directing means is adjusted relative

10 to said discharge opening by rotating both said directing means and said threaded connecting means.

23. The nozzle assembly of claim 14 wherein said internal wall surface proximate to said discharge opening has an angle substantially corresponding to said angle of said angled fluidized particulate stream contacting surface.

15 24. A nozzle assembly for directing a fluidized particulate stream from a supply source, said nozzle comprising: a. a cylindrical conduit having an exterior wall surface, a first opening with a threaded coupling means for affixing said nozzle to said fluidized particulate supply source, a second, discharge opening distally positioned downstream from said first

20 opening and an internal wall surface defining a flow channel through which said fluidized particulate stream flows; b. a retaining means affixed to a surface of said conduit wherein said retaining means includes a member extending transversely relative to a flow direction of said fluidized particulate stream inside of said conduit and wherein said member

25 includes a first end, a second end and a first substantially central bore opening, wherein said first central bore opening has a set of internal threads; c. an adjustable directing means positioned proximate to said discharge opening for directing at least a portion of said fluidized particulate stream radially outward, said directing means having a second substantially central longitudinal bore which

30 includes a second set of internal threads; and d. a rod having a set of mating external threads through which said is rod is threaded into said first and second central bore openings whereby said directing means is adjustably affixed to said retaining means.

25. The nozzle assembly of claim 24 wherein said thread is cut into the interior wall surface.

26. The nozzle assembly of claim 24 wherein said transversely extending member is extends through an opening in said interior and exterior walls and is immovably affixed to said exterior wall.

27. The nozzle assembly of claim 24 wherein said first and second ends are immovably affixed to said interior wall.

28. The nozzle assembly of claim 24 wherein said rod includes a central through extending channel.

29. The nozzle assembly of claim 24 wherein said adjustable directing means includes an angled fluidized particulate stream contacting surface and wherein the angle of said contacting surface is from about 25 to 45 degrees.

30. The nozzle assembly of claim 24 wherein said second longitudinal bore extends through said directing means and wherein said directing means is adjusted relative to said discharge opening by rotating said directing means on said threaded rod.

31. A method for cleaning the interior wall surface of a pipe comprising contacting said interior wall surface with a fluidized particulate stream injected into said pipe through a nozzle comprising: a. a cylindrical conduit having an exterior wall surface, a first opening with a coupling means for affixing said nozzle to said fluidized particulate supply source, a second, discharge opening distally positioned downstream from said first opening and an internal wall surface defining a flow channel through which said fluidized particulate stream flows; b. a retaining means affixed to a surface of said conduit; c. an adjustable directing means positioned proximate to said discharge opening for directing at least a portion of said fluidized particulate stream radially outward; and d. connecting means for affixing said directing means to said retaining means.

32. The method of claim 32 wherein a ratio of an inside pipe diameter to an outside cylindrical conduit diameter is from about 1.1 to about 6.

33. The method' of claim 32 wherein a ratio of an inside pipe diameter to an outside cylindrical conduit diameter is from about 1.1 to about 3.