US3226258A - Method for removing incrustations - Google Patents

Description

new 1965 c. H. HEIST METHOD FOR REMOVING INCRUSTATIONS Filed Sept. 25, 1965 INVENTOR. F/m'WZ'ez-s fl. ]'[e is? BY W fl/ ATTORNEY.-

United States Patent M 3,226,258 METHOD FOR REMOVING INCRUSTATHONS Charles H. Heist, East Aurora, N.Y., assiguor to C. H. Heist Ohio Corporation, Buffalo, N.Y., a corporation of New York Filed Sept. 25, 1963, Ser. No. 311,414 1 Claim. (Cl. 134-8) The present invention relates to an improved method for removing incrusted foreign matter from the insides of tubes and the like.

In heat exchangers, boilers, and tubes which are utilized to conduct chemicals in industrial processes there is a depositing of incrustations on the insides of said tubes which initially impede the flow of fluids through said tubes and eventually block off the tubes completely so that the processes which utilize said tubes operate at greatly reduced efliciencies with an obvious attendant economic loss. In the past, various methods have been utilized for removing the above-mentioned incrustations. Included among these methods was the use of a rotary drill mounted at the end of a spindle. However, this method had the primary shortcoming of being very costly in that the drill became dull with short periods of use and therefore required frequent replacement and sharpening. In the foregoing prior art method it was common to use a fluid for flushing the debris which was drilled out of the tube. However this flushing in no way acted on the incrustation to aid in the dislodging thereof from its position on the inside of the tube. Other methods were also utilized which relied solely on the projecting of high pressure fluids against deposits on the insides of tubes to dislodge foreign matter therefrom. However these methods were deficient in that, while the fluids were under high pressure, the pressure was frequently greatly dissipated and reduced by the time that the fluid impinged on the deposits thereby resulting in an unsatisfactory cleaning action. Furthermore, the use of high pressure fluid by itself could not do an effective cleaning job. It is with the overcoming of the foregoing shortcomings of the prior art that the present invention is concerned.

It is accordingly the primary object of the present invention to provide an improved method for removing extremely hard incrustations from the insides of tubes and the like which is highly efficient in that the incrustations are removed rapidly and completely without leaving traces which would serve as focal points for subsequent build-up of incrustations.

Another object of the present invention is to provide an improved method for removing incrustations from the insides of tubes and the like which is highly economical in that the apparatus utilized to remove said incrustations does not wear out rapidly and does not require frequent replacement. Other objects and attendant advantages of the present invention will readily be perceived hereafter.

The improved method of removing hardened incrusted foreign matter from the insides of tubes or the like comprises the steps of effecting a drilling action within said tube to disengage said foreign matter therefrom and simultaneously projecting high pressure fluid radially and/or axially of the direction of drilling in the area of said drilling, said fluid being under sufiicient pressure, when it impinges on said incrustations, to provide an eroding action whereby said eroding action cooperates with and complements said drilling to facilitate the removal of said foreign matter by (l) eroding a portion of the foreign matter which is subsequently removed by said drilling and by (2) removing traces of foreign matter which remain on the inside of said tube after said drill- 3,226,258 Patented Dec. 28, 1965 ing and by (3) acting in concert with said drilling, to thereby rapidly and completely remove said incrustations of foreign matter from the inside of said tube. The drill not only performs its function as a drill but also acts as a guide to center the high pressure fluid which is discharged onto the inside of the tube to thereby cause it to act most effectively.

The apparatus of the present invention for removing incrusted foreign deposits from the insides of tubes includes a drill, a motor, a hollow spindle connecting said drill and said motor to thereby transmit. motion from said motor to said drill, a source of pressurized fluid under pressure suflicient to erode said foreign matter when said fluid is impinged thereon, conduit means for conducting said pressurized fluid from said source to said hollow spindle, and apertures in said drill for projecting said pressurized fluid in the area in which said drill is rotated to thereby remove said foreign matter by a combined drilling and eroding action. The present invention will be more fully understood when the following portions of the specification are read in conjunction with the accompanying drawings wherein:

FIG. 1 is a schematic view of the improved apparatus which is utilized for practicing the improved method of the present invention; and

FIG. 2 is a cross sectional view of a portion of the apparatus of the present invention.

In FIG. 1 an air motor 10 is shown having a housing 11 including a compressed air inlet 12 and a compressed air outlet 13. A pair of handles 14 (one on each opposite side of housing 11) are provided for grasping by the motor operator to guide the direction of movement of said motor. An eye hook 15 is suitably secured to housing 11 for hanging motor 10 from a support because of its weight. A grip 16 is pivotally mounted on housing 11 and includes an extension 17 connected to grip 16 by O-portion 18, extension 17 being in engagement with the stem of a valve (not shown) which controls the amount of compressed air which is permitted to enter housing 11 from conduit 12. In this manner the speed of motor 10 is controlled. Motor 10 may be in all respects identical to motor number CC-325-1 which is manufactured by the Airetool Manufacturing Company of Springfield, Ohio, except for certain modifications which will be described hereafter in conjunction with FIG. 2.

A pump 19 is provided for receiving water which enters this pump from conduit 20 and leaves said pump through conduit 21. Pump 19 is capable of increasing the water pressure to a magnitude of approximately 4,000 pounds per square inch. However, in the instant process which will be described in greater detail hereafter, the pressure need only be of the magnitude of approximately 3,000 pounds per square inch. The end of conduit 21 remote from pump 19 is in communication with valve 22, which in turn is mounted on nipple 23 extending from portion 24 of housing 11. More specifically, nipple 23 fits into bushing 25 which is threaded into housing portion 24 and set screw 26 retains said bushing 25 in position. A second bushing 27 threads into the internal portion of bushing 25, as is clearly shown in FIG. 2, and a heavy duty gasket or seal 28 is wedged between wall 29 of bushing 25 and end wall 30 of bushing 27. Gasket or seal 28 is of sufliciently sturdy construction and sealing power to prevent leakage of the fluids under a pressure of approximately 3,000 pounds per square inch. Rotatably mounted within bushing 27 is the right end of hollow spindle 31, the left end thereof being splined or otherwise keyed to gear 32 which is in mesh with pinion 33 driven by shaft 34 of the air driven rotor (not shown) within motor 10. A pair of thrust bearings 35 are suitably mounted within housing portion 36 to limit endwise movement of spindle 31.

Thus, because of seal 28 in conjunction with bushings 25 and 27, the high pressure fluid in conduit 21 is conducted into hollow rotating spindle 31 without leakage. This fluid is transmitted by hollow spindle 31 into hollow spindle 37 which is threaded onto hollow spindle 31 at 38. The end of hollow spindle 37 remote from connection 38 mounts a drill bit 39 having a pair of apertures 40 on opposite sides thereof which project the high pressure fluid from spindle 37 axially forwardly of the direction of rotation of drill 39. Furthermore a pair of apertures 41 are located on opposite sides of drill 39 for projecting high pressure fluid radially of the direction of movement of the drill 39 as it moves through tube 42 forming a part of heat exchanger 43 or the like. Apertures 40 and 41 in essence project jets of fluid which provide the desired eroding action.

It will readily be seen that the high pressure fluid being discharged at a magnitude of approximately 3,000 pounds per square inch is caused to impinge on the incrustations within the tube in the vicinity of the area in which drilling occurs. The pressurized fluid, when it impinges on the incrustations, has suificient force to actually erode said incrustations. Thus there is a three-fold action which is effected by the combined drilling and eroding, namely, (1) the high pressure fluid which is projected forwardly of the drill tears away or erodes a part of the incrustations 40 lying ahead of the drill, (2) the high pressure fluid which is projected in the vicinity in which the drilling actually occurs aids the drilling to thereby effect removal of the incrustations 41 within the tube by combined eroding and drilling action, thereby prolonging drill life by minimizing the wear to which the drill is subjected, and (3) the high pressure fluid being projected from apertures 41 impinge on the sides of the conduit When these sides are no longer in engagement with the drill to thereby remove any rifling 42' of incrustations which may remain within the tube to thereby remove any irregular surfaces which may act as focal points for the accumulation of subsequent incrustations. It is also to be especially noted that the drill acts as a guide to cause the high pressure fluids which are projected from apertures 40 and 41 to follow a predetermined path by being projected in a predetermined direction. Furthermore the drill 39 regulates the spacing of the apertures from the walls of the tube to thereby insure that the jets of fluid are projected with the desired force onto the walls of the tube.

It will also be appreciated that when the drill 39 is removed from tube 42 it travels from left to right, whereas when it was inserted it traveled from right to left in FIG. 1. By maintaining the discharge of high pressure fluid from apertures 40 and 41 during said Withdrawal while drill 39 is rotating, the finishing touches are provided to the cleaning operation to thereby completely clean said tube of any incrustations which may have remained after the three-faceted action described in detail above.

It is to be noted that drill 39 was described in FIG. 1 as having apertures which project the high pressure fluid both forwardly and radially of the direction of movement of the drill. However it will be readily appreciated that certain modifications may be made within the scope of the present invention, namely, that a drill bit having only radial apertures may be utilized or having only forwardly projecting apertures may be utilized and the number and location of said apertures may be varied to meet the exigencies of any particular type of cleaning operation, it being appreciated that different types of incrustations require different types of treatment.

It is to be especially noted that the use of high pressure fluids to provide an eroding action causes the instant method to differ greatly from those prior art methods which utilized fluids to provide only a flushing action which merely carried the dislodged debris away from the area of drilling. The use of high pressure fluids of the magnitude described herein inherently performs the flushing function of the prior art, in addition to the eroding function which accompanies the drilling, as described above.

It is also to be noted that while the fluid which is utilized, has been described above as water, other suitable fluids may also be used, or the water may contain abrasive material to provide an improved eroding action.

While preferred embodiments of the present invention have been disclosed, it will readily be appreciated that the present invention is not limited thereto, but may be otherwise embodied within the scope of the following claim.

I claim:

A method of removing extremely hard incrusted foreign matter from the inside surface of a tube comprising the steps of effecting a drilling action through said tube to disengage said foreign matter therefrom and simultaneously projecting fluid axially of the direction of said drilling in the area of said drilling, said fluid being under a pressure of approximately 3,000 pounds per square inch to thereby effect an erosion of said foreign matter and provide an action wherein said eroding cooperates with and complements said drilling to facilitate the removal of said foreign matter by acting simultaneously on the same portions of said extremely hard incrusted foreign matter in concert with said drilling, by loosening foreign matter which is subsequently removed by said drilling and by removing foreign matter which remains on the inside of said tube after said drilling.

References Cited by the Examiner UNITED STATES PATENTS 1,161,122 11/1915 Froussard 15104.1 1,218,765 3/1917 Hauer l5-l04.1 1,628,070 5/1927 Sladden 15-104.12 1,803,425 5/ 1931 Cunningham.

1,932,068 10/1933 Englebright et a1. 15104.1 X 2,218,130 10/1940 Court 15--104.12 2,313,042 3/1943 Bay 15104.1 2,336,293 12/1943 Pletcher 15104.12 2,423,257 7/1947 Schott et al 15--104.1 2,710,980 6/1955 Pletcher 15104.12 2,932,836 4/1960 Pletcher 15104.12

CHARLES A. WILLMUTH, Primary Examiner.

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