US3740790A

US3740790A - Apparatus for cleaning waveguide and similar pipes

Info

Publication number: US3740790A
Application number: US00204983A
Authority: US
Inventors: D Koppes
Original assignee: Bell Telephone Laboratories Inc
Current assignee: AT&T Corp
Priority date: 1971-12-06
Filing date: 1971-12-06
Publication date: 1973-06-26
Anticipated expiration: 1990-06-26

Abstract

A device for cleaning waveguide and similar pipes comprises a piston having inlet and outlet gas ports therein joined by passages through the piston and gas seals and gas deflecting means located on opposite sides of the outlet ports. When pressurized gas is introduced against a seal, it is directed into the inlet port, through the passage and out the gas outlet port. The gas is then directed by the gas deflecting means at relatively high velocity along the inner surface of the waveguide thereby driving any contaminants along the waveguide. The high velocity gas flow along the inner surface provides both a moisture absorbing effect and a moisture driving effect for more efficient cleaning. The pressure differential across the gas seal propels the device forward through the waveguide.

Description

[ June 26, 1973 APPARATUS FOR CLEANING WAVEGUIDE AND SIMILAR PIPES [75] Inventor: David Nelson Koppes, Bemards Township, County of Somerset, NJ.

[73] Assignee: Bell Telephone Laboratories,

Incorporated, Murray Hill, NJ.

[22] Filed: Dec. 6, 1971 [21] Appl. No.: 204,983

[52] US. Cl. 15/312 R, 15/l04.06 R, 15/405 [51] Int. Cl A47] 5/14 [58] Field Of Search 15/l04.06 R, 312 R, v I 15/405, 406

[56] I References Cited UNITED STATES PATENTS 3,659,305 5/1972 Powers l5/l04.06 R 1,855,646 4/1932 obel'hubel' l5/l04.06 R

DRY PRESSUWZED Primary Examiner-John Petrakes Assistant Examiner-C. K Moore Attorney-R. J. Guenther et al.

[5 7] ABSTRACT A device for cleaning waveguide and similar pipes comprises a piston having inlet and outlet gas ports therein joined by passages through the piston and gas seals and gas deflecting means located on opposite sides of the outlet ports. When pressurized gas is. introduced against a seal, it is directed into the inlet port, through the passage and out the gas outlet port. The gas is then directed by the gas deflecting means at relatively high velocity along the inner surface of the waveguide thereby driving any contaminants along the waveguide.

The high velocity gas flow along the inner surface provides both a moisture absorbing effect and a moisture driving effect for more efficient cleaning. The pressure differential across the gas seal propels the device forward through the waveguide.

5 Claims, 1 Drawing Figure APPARATUS FOR CLEANING WAVEGUIDE AND SIMILAR PIPES BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to waveguide transmission systems and more particularly to apparatus for cleaning contaminants from waveguide and similar pipes.

2. Description of the Prior Art The presence of contaminants such as oxygen and water in liquid or vapor form within a waveguide transmission system has a very deleterious effect upon certain bands of frequencies or signals being transmitted therethrough. For this reason it is expected that during the initial installation any commercial waveguide transmission line will be completely cleaned and then filled with a gas such as nitrogen having suitable low electrical loss characteristics. Also it is certain that failures in such a waveguide line will occur during its expected long life which will allow the ingress of contaminants. Consequently, the line will again have to be cleaned and refilled with gas.

Devices commonly called pigs are currently available for cleaning petroleum pipelines or similar pipelines of contaminants. However, the degree of contamination acceptable in petroleum pipelines would be completely unacceptable in a waveguide transmission line. Some of these existing cleaning devices utilize pressurized gas to propel the device through the pipes and to vaporize or to absorb liquid contaminants in the pipe. However, none of the existing devices fully utilize such pressurized gas to absorb moisture and also to drive or force contaminants along the waveguide. Thus these present devices would require an excessive number of passages through a waveguide to achieve the required low degree of contamination.

Accordingly, it is an object of this invention to improve devices for cleaning waveguide and similar pipes so that more contaminants can be removed with each passage of such device through the waveguide.

Another object is to improve the efficiency of devices for cleaning waveguide and similar pipes.

A more specific object is to more efficiently utilize the pressurized gas which propels cleaning devices through a waveguide.

SUMMARY OF THE INVENTION The foregoing objects and others are achieved in accordance with the invention by a cleaning device comprising a piston or body having a series of gas inlet and outlet ports therein and gas flow passages or tunnels within the piston interconnecting respective pairs of the inlet and outlet ports. Gas seals are mounted along the piston adjacent the outlet ports and form gas-tight seals with the inner wall of the waveguide being cleaned. Gas deflectors also are mounted along the piston and spaced from the gas seals by the outlet ports. The outer periphery of the deflector forms an annularlike gas nozzle with the interior wall of the waveguide. When pressurized gas is introduced behind the cleaning device it enters an inlet port, traverses a tunnel and exits an outlet port between a seal and a gas deflector. The deflector directs the gas flow through the nozzle at relatively high velocity along the inner wall of the waveguide. This gas flow drives contaminants such as water droplets along the inner surface in addition to simultaneously vaporizing or absorbing a portion of such liquid contaminants. The pressure differential across the seal propels the device forward through the waveguide so that the seal wipes the inner wall clean of any remaining contaminants.

BRIEF DESCRIPTION OF THE DRAWING The invention will be more fully comprehended from the following detailed description in conjunction with the drawing the single FIGURE of which is a representation, partly in section, of the cleaning device of this invention installed in a waveguide.

DETAILED DESCRIPTION Referring now to the drawing, there is shown a waveguide 2 or similar pipe in which a cleaning device 4 is inserted for cleaning contaminants 18 therefrom. Cleaning device 4 comprises a substantially cylindrical piston or body 6 having a series of gas inlet and

outlet ports

8 and 10, respectively, formed therein. Respective ones of the inlet ports 8 are connected to associated ones of outlet ports 10 by tunnels or gas flow passages 12 formed in the body of piston 6. Piston 6 can comprise metal or a suitable plastic and advantageously can be formed from piece parts in which

ports

8 and 10 and passages 12 have been formed by well-known machining techniques. The piece parts are joined by an appropriate adhesive or other well-known mounting means.

Mounted around piston 6 and located between the associated inlet and

outlet ports

8 and 10, respectively, are gas seals 14. Seals 14 contact the inner surface 3 of waveguide 2 around the entire periphery thereof and form gas-tight seals therewith. Thus pressurized gas passing from one side of seal 14 to the other side must enter inlet port 8, traverse passage 12 and exit outlet port 10. Seals l4 advantageously comprise a flexible material such as rubber or a suitable plastic. Alternatively, seal 14 can comprise a metal ring with a suitable flexible strip or wiper around the outer periphery thereof. Seal 14 contacts inner surface 3 with sufficient force to provide a good wiping action when seal 14 moves relative to surface 3. Seals l4 advantageously can have a flange 15 around the outer periphery to increase the wiping surface and thereby improve the efficiency of the wiping action.

Also mounted around piston 6 and located adjacent outlet ports 10 opposite seals 14 are gas deflectors or discs 16. Deflectors 16 can comprise metal or plastic discs. The outer diameter of a deflector 16 is slightly smaller than the inner diameter of waveguide 2 so that deflector 16 forms an annular-type nozzle 22 with inner surface 3.

When a pressurized gas 20 is introduced behind cleaning device 4, gas 20 enters inlet ports 8, travels through passages 12 and exits outlet ports 10. Deflectors l6 require gas 20 to flow toward inner surface 3 and exit nozzle 22 at substantially high velocity along surface 3. Thus any particles of contaminants 18 adhering to surface 3 will be loosened and driven forward through waveguide 2. This flow of gas at relatively high velocity along surface 3 is particularly advantageous because contaminants clinging to surface 3 are normally the most difficult to remove from a waveguide 2 or similar pipe.

The pressure of gas 20 decreases as it traverses the indicated path because of the frictional losses developed when a fluid flows through a passage or orifice.

The pressure differential across'seal 14 is sufficient to propel device 4 forward through waveguide 2 thereby causing seal 14 to wipe and further clean surface 3. All loosened contaminants 18 are driven forward through waveguide 2 as device 4 moves forward. The speed of device 4 can be controlled by regulating the pressure differential across seal 14. This can be accomplished by controlling the source pressure of gas 20, by controlling the exhaust pressure downstream of device 4, by varying the size of passages 12 and

orifices

8 and 10, or by inserting pressure regulators, known in the art, in passages 12.

The flow of gas 20 from nozzles 22 at relatively high speed along or tangential to surface 3 utilizes gas 20 in a very efficient manner in cleaning waveguide 2. With such a flow gas 20 provides both a driving force and an absorbing or evaporating force to remove contaminants such as water droplets adhering to surface 3. As previously mentioned, such contaminants are usually the most difficult to remove. In present pipeline cleaning devices no deflectors such as deflector 16 are utilized. Thus only the absorbing or vaporizing force of the pressurized gas is utilized by such'devices to remove contaminants adhering to the inner surface of the pipe. Because of this less efficient utilization of the pressurized gas, repeated passages of the cleaning device are required to achieve the same degree of cleaning obtained by applicants device in a single pass.

Although three sets of seals 14 and deflectors 16 are shown, it should be apparent that a different number can be utilized depending upon such factors as available source pressure for gas 20 and the degree of cleaning required. It is likewise apparent that the device 4 can be readily modified to work with waveguides having different cross sectional configurations. Further device 4 can be made flexible to facilitate the negotiation of bends in the waveguide.

Various other modifications can be made to the described embodiment without departing from the spirit and scope of the invention as set forth in the following claims.

What is claimed is:

1. Apparatus for cleaning contaminants from waveguide and similar pipes comprising, in combination:

a piston having a series of gas inlet and outlet ports therealong and gas passages through said piston interconnecting respective associated ones of said inlet and outlet ports;

gas seals mounted around said piston between said associated ones of said inlet and outlet ports and contacting the interior surface of said waveguide around the entire periphery therewith to form gastight seals therewith so that said piston can be propelled through said waveguide by introducing a pressurized gas against said seal, said seal causing said gas to enter said inlet port, travel through said passage and exit said outlet port; and

gas deflectors mounted around said piston adjacent said outlet ports so that said outlet ports are located between said seals and said deflectors, said deflectors having outer peripheries spaced from said interior surface and forming gas flow nozzles therewith so that said gas exiting said outlet port is directed through said nozzle at a relatively high velocity along said interior surface thereby removing said contaminants from said surface.

' 2. Apparatus in accordance with claim 1 wherein said seal comprises a flexible material for wiping and cleaning said interior surface as said apparatus is propelled through said waveguide.

3. Apparatus in accordance with claim 1 including first means for regulating the pressure of said gas introduced against said seal; and

second means for regulating the pressure of said gas exiting said nozzle so that the speed of said apparatus through said waveguide can be controlled.

4. Apparatus in accordance with claim 1 including pressure regulating means in said passages for controlling the pressure differential across said seals so that the speed of said apparatus through said waveguide can be controlled.

5. Apparatus for cleaning waveguide and similar pipes comprising, in combination:

a body;

a seal on said body for supporting said body within said waveguide, said seal forming a gas-tight seal with the interior surface of said waveguide so that said apparatus can be propelled through said waveguide by introducing a pressurized gas against said seal, said body having passages and outlet ports therein through which said pressurized gas can move to bypass said seal; and

a disc mounted on said body adjacent said outlet port opposite said seal, said disc forming an annulartype orifice with said interior surface so that said gas is directed through said orifice at a relatively high velocity along said surface whereby contaminants are removed from said surface.

Claims

1. Apparatus for cleaning contaminants from waveguide and similar pipes comprising, in combination: a piston having a series of gas inlet and outlet ports therealong and gas passages through said piston interconnecting respective associated ones of said inlet and outlet ports; gas seals mounted around said piston between said associated ones of said inlet and outlet ports and contacting the interior surface of said waveguide around the entire periphery therewith to form gas-tight seals therewith so that said piston can be propelled through said waveguide by introducing a pressurized gas against said seal, said seal causing said gas to enter said inlet port, travel through said passage and exit said outlet port; and gas deflectors mounted around said piston adjacent said outlet ports so that said outlet ports are located between said seals and said deflectors, said deflectors having outer peripheries spaced from said interior surface and forming gas flow nozzles therewith so that said gas exiting said outlet port is directed through said nozzle at a relatively high velocity along said interior surface thereby removing said contaminants from said surface.

2. Apparatus in accordance with claim 1 wherein said seal comprises a flexible material for wiping and cleaning said interior surface as said apparatus is propelled through said waveguide.

3. Apparatus in accordance with claim 1 including first means for regulating the pressure of said gas introduced against said seal; and second means for regulating the pressure of said gas exiting said nozzle so that the speed of said apparatus through said waveguide can be controlled.

5. Apparatus for cleaning waveguide and similar pipes compriSing, in combination: a body; a seal on said body for supporting said body within said waveguide, said seal forming a gas-tight seal with the interior surface of said waveguide so that said apparatus can be propelled through said waveguide by introducing a pressurized gas against said seal, said body having passages and outlet ports therein through which said pressurized gas can move to bypass said seal; and a disc mounted on said body adjacent said outlet port opposite said seal, said disc forming an annular-type orifice with said interior surface so that said gas is directed through said orifice at a relatively high velocity along said surface whereby contaminants are removed from said surface.