Assembly for removing a device from a boiler

An assembly and a method for removing a removable device from a wall box are provided. The removable device forms a substantially fluid-tight wall box seal with a wall box opening when the removable device is in a first position. The assembly for removing the removable device includes a sealing assembly located adjacent to the wall box opening and forming a substantially fluid-tight seal with a sealing portion of the removable device when the removable device is in a second position with respect to the wall box.

BACKGROUND

The invention relates to a method and an assembly for removing a device from a wall box for a large-scale combustion device. The wall box is located within a wall port of the combustion device in order to receive the device, such as a cleaning device or an imaging device.

During the operation of large-scale combustion devices, such as boilers that burn fossil fuels, slag and ash encrustations develop on interior surfaces of the boiler. The presence of these deposits degrades the thermal efficiency of the boiler. Therefore, it is periodically necessary to remove such encrustations. Various removable cleaning devices are currently used to remove these encrustations.

One such type of removable cleaning device includes a device referred to as a “sootblower”. Sootblowers are used to project a stream of cleaning fluid, such as air, steam or water, into the interior volume of the boiler. In the case of long retracting type sootblowers, a lance tube is periodically advanced into and withdrawn from the boiler. As the lance tube is advanced into and withdrawn from the boiler, it rotates or oscillates in order to direct one or more jets of cleaning fluid at desired surfaces within the boiler. In the case of stationary sootblowers, the lance tube is maintained within the boiler during periods of use and during periods of non-use. Sootblower lance tubes project through openings in the boiler wall, referred to as wall ports. The wall ports may include a mounting assembly, such as a wall box, in order to properly position the lance tube with respect to the boiler wall.

Retracting sootblowers are typically partially or completely removed from the wall box when not in use. Therefore, retracting sootblowers are frequently inserted to and removed from the boiler interior volume. Although stationary sootblowers are typically maintained within the boiler interior volume, they may need to be removed from the boiler for servicing the sootblower or for other various purposes. Therefore, retracting sootblowers and stationary sootblowers are both considered to be removable cleaning devices.

Another such type of removable cleaning device is commonly referred to as a “water cannon”. Water cannons involve the use of a monitor or nozzle positioned within a wall port in order to eject a stream of fluid, such as water, into the interior volume of the combustion device. The water cannon nozzle typically includes a pivot joint to permit adjustment of the direction of the stream of fluid. Similarly to the sootblower, the water cannon nozzle is positioned within the wall port via a mounting assembly, such as a wall box. Unlike the sootblower, however, the water cannon nozzle preferably includes a pivotable ball joint coupled with the wall box in order to adjust the direction of the stream of fluid flowing into the boiler interior volume. Due to the presence of the pivotable ball joint, the wall port for a water cannon assembly is typically larger than the wall port for a sootblower.

Similarly to the stationary sootblower, the water cannon nozzle is typically maintained within the boiler during periods of use and during periods of non-use. However, water cannon assemblies may need to be removed from the boiler for servicing the water cannon or for other various purposes. Therefore, water cannon assemblies are also considered to be removable cleaning devices.

Other removable devices, besides cleaning devices, may penetrate the boiler wall via a wall port in order to perform a desired function. One such device is an imaging device, such as an infrared imaging device. Imaging devices are often used to examine the interior volume and the interior surfaces of the boiler in order to check the boiler status or to perform maintenance on the boiler. Similarly to the cleaning devices, the imaging device typically penetrates a wall port in order to view the boiler interior volume. The imaging device may be extended into the boiler interior volume similarly to a sootblower lance, it may be coupled with a pivoting ball joint similarly to a water cannon assembly, or it may be used in any other appropriate configuration. Regardless of the configuration of the imaging device, it typically includes a mounting assembly located within the boiler wall port.

Depending on the configuration of the imaging device, it may be typically maintained within the boiler during periods of use and during periods of non-use, or it may typically be removed from the boiler during periods of non-use. Regardless of the typical configuration of the imaging device with respect to the boiler, the imaging device may need to be removed from the boiler for servicing the device or for other various purposes. Therefore, imaging devices are considered to be removable cleaning devices regardless of their typical configuration with respect to the boiler.

Boiler gases may pose various health risks and dangers, such as including toxic or otherwise dangerous compositions. Therefore, it is advantageous to include substantially fluid-tight seal(s) between various components of the wall box and of the removable device.

Furthermore, boiler gases typically reach extremely high temperatures. Therefore, it is advantageous to include heat-resistant seal(s) between various components of the wall box and of the removable device in order to protect the boiler users from the boiler temperatures and in order to minimize fire hazards. The fluid-tight seals and the heat-resistant seals may be the same seals performing multiple functions.

Positive-pressure boilers operate with an internal pressure higher than the ambient pressure some boilers. Therefore, due to the internal pressure of positive-pressure boilers, it may be especially difficult to maintain the substantially seals and prevent boiler gases from escaping during removal of the removable device from a positive-pressure boiler.

Other types of boilers, such as ambient-pressure boilers and negative-pressure boilers, also may experience undesirable gas exchange with the ambient air if preventative measures are not taken. Similarly, the heat of the boiler gas may pose health and fire hazards regardless of the pressure differential between the boiler interior and the ambient air. Therefore, it is desirable to maintain the seals during removal of the removable device in all types of boilers.

As seen from above, it is desirous to provide an improved system and an improved method for protecting boiler users, minimizing fire hazards, and substantially preventing fluid exchange between the boiler and the ambient air during removal of various removable devices from the boiler wall box.

SUMMARY

In overcoming the disadvantages and drawbacks of the known technology, the current invention provides an assembly and a method for removing a removable device from a wall box. The wall box includes a wall box opening for receiving the removable device and for forming a substantially fluid-tight wall box seal when the removable device is in a first position with respect to the wall box.

The assembly for removing the removable device from the wall box includes a sealing assembly located adjacent to the wall box opening. The removable device includes a sealing portion for forming a substantially fluid-tight seal with the sealing assembly when the removable device is in a second position with respect to the wall box.

In one configuration, the sealing assembly includes a sealing collar assembly coupled to the wall box. The sealing collar assembly selectively forms the seal when the removable device is in the second position. The sealing portion of the removable device may include an adaptor having an outer surface for forming the seal with the sealing collar assembly. Additionally, the sealing panel assembly may include an inner surface having a substantially cylindrical shape and the adaptor outer surface may have a substantially circular cross-section.

In another configuration, the sealing assembly further includes a sealing panel assembly for selectively forming a substantially fluid-tight sealing panel seal when the removable device is in the second position. The sealing panel assembly may include a sealing panel base portion that forms a substantially fluid-tight base portion seal with the wall box. Furthermore, the sealing panel may include a movable panel for forming the sealing panel seal when the removable device is in the second position.

In yet another configuration, the assembly for removing the removable device from the wall box includes an extracting assembly for moving the removable device from the first position to the second position. The extracting assembly may include a threaded screw, a rotatable threaded collar for receiving the threaded screw, and an anti-rotation device for substantially preventing rotation of the threaded screw.

In another configuration, removable device is received within a sleeve that includes an aspirating opening extending through the sleeve. Furthermore the assembly for removing the removable device from the wall box includes an aspirating device coupled with the sleeve order to form a substantially fluid-tight aspirating seal between the aspirating device and the seal. The aspirating device further supplies an aspirating fluid flow through the aspirating opening of the sleeve.

In another configuration, the current invention provides an assembly for removing a water cannon assembly from a wall box opening. The wall box is coupled with a combustion device having an interior volume defined by a wall. The water cannon assembly includes a steering tube having a steering tube conduit, a supply tube located within the steering tube and supplying a cleaning fluid to the combustion device interior volume, and a pivot joint connected to the steering tube. The pivot joint forms a substantially fluid-tight wall box seal with the wall box opening when the water cannon assembly is in a first position with respect to the wall box.

The assembly for removing the water cannon assembly from the wall box opening includes an aspirating device coupled with the steering tube and a sealing assembly located adjacent to the wall box opening. The aspirating device forms a substantially fluid-tight aspirating seal with the steering tube and supplies an aspirating fluid flow through an aspirating opening of the steering tube and into the steering tube conduit.

In another configuration, the current invention provides a method for removing a water cannon assembly from a wall box opening. The method includes the steps of coupling an aspirating device to the steering tube in order to form a substantially fluid-tight aspirating seal; supplying an aspirating fluid flow through the aspirating opening and into the conduit via the aspirating device; removing the supply tube from the steering tube; removing the aspirating device from the steering tube; connecting a sealing panel assembly to the wall box such that a sealing panel of the sealing panel assembly is adjacent to the wall box; moving the water cannon assembly to a second position such that the sealing portion of the water cannon assembly forms a substantially fluid-tight sealing panel assembly seal with the sealing panel assembly; and moving the sealing panel to a closed position such that the sealing panel and the wall box form a substantially fluid-tight second sealing panel assembly seal.

In yet another configuration, the current invention provides a sealing box at least partially defining a sealing chamber encompassing at least a portion of the water cannon assembly and fluidly sealing the sealing chamber from the ambient air. Furthermore, an access assembly provides access to the portion of the water cannon assembly while the sealing chamber is substantially fluidly sealed from the ambient air.

In one configuration, the method further includes the step of inserting a steering tube plug into the steering tube such that a sealing surface of the steering tube plug cooperates with a sealing surface of the steering tube to form a substantially fluid-tight steering tube plug seal. The method also includes the step of extracting the water cannon assembly from a collar portion of the sealing panel assembly. Furthermore, the method includes the step of inserting a combustion device plug into sealing panel assembly in order to form a substantially fluid-tight third sealing panel seal. Additionally, the sealing panel is moved from the closed position to an open position. A combustion device plug is also inserted into the wall box opening to form a substantially fluid-tight second wall box seal.

The above configurations of the present invention may permit a removable device to be removed from a combustible device while the combustible device has a relatively high interior temperature or while the combustible device is still in operation, thus potentially reducing maintenance time and potentially reducing hazardous conditions caused by the combustible device.

DETAILED DESCRIPTION

Referring now to the present invention,FIG. 1is an exploded view of a removable device to be selectively coupled with a wall box10that is mounted to a combustion device via a mounting plate12. The removable device shown is a water cannon assembly14, but it may be any appropriate device, such as a sootblower or an imaging device. The water cannon assembly14receives a cleaning fluid and ejects the cleaning fluid into the interior volume of the boiler, as will be discussed below in more detail.

In order to effectively clean various sections of the boiler interior volume, the water cannon assembly14is pivotably mounted within a wall box opening16. More specifically, a pivot joint18of the water cannon assembly includes a sealing portion20that forms a substantially fluid-tight seal with a pivot joint socket22that is received within the wall box opening. The pivot joint socket22preferably includes an interior portion24located within the boiler interior volume and an exterior portion26located external to the boiler. The exterior portion26performs two functions: forming a water-tight seal with the pivot joint20and permitting the pivot joint20to pivot at a wide range of angles within the pivot joint socket22. Therefore, it is advantageous for the exterior portion26of the pivot joint socket22to have a generally circular inner surface28, and for the sealing portion20of the pivot joint18to be generally spherical.

Similarly to the exterior portion26, the interior portion24of the pivot joint socket22forms a substantially water-tight seal with the pivot joint18and permits pivoting movement of such. Therefore, the interior portion24of the pivot joint socket22also preferably includes a generally circular inner surface30. The interior portion24also may include a plurality of seal air openings, which will be discussed with more detail below.

The pivot joint18is connected to a steering tube32via a snap fit connection, or other appropriate connection such as a tab-and-slot connection. The steering tube32is also connected to a steering assembly34via a cardon joint36. The steering assembly34is preferably a wheel-shaped mechanism, not unlike an automotive steering wheel, that controls the pivoting movement of the steering tube32and the pivot joint18. The steering assembly34preferably includes at least two support arms37,38that each allow pivotable movement about a different axis, thus allowing the steering assembly34to travel along an imaginary path that is substantially hemispherical.

The steering assembly34may also be coupled with a pair of actuating arms (not shown) that apply actuating forces to the steering assembly. As is known in the art, the actuating arms may be in electrical connection with a controller in order to automatically adjust the position of the steering assembly34and thus automatically adjust the pivot angle of the water cannon assembly14.

The cardon joint36is preferably located adjacent to the centerpoint of the steering assembly34and permits a pivotable connection between the steering tube32and the steering assembly34such that the steering tube32is always substantially perpendicular to a plane defined by the circular portion of the steering assembly34. Alternatively, any appropriate connection may be instead of a cardon joint36.

A supply tube40is preferably received within the steering tube32in order to supply the cleaning fluid for the interior volume of the combustible device. The supply tube40preferably includes a nozzle42to be inserted within the pivot joint18and to properly control the spray of the cleaning fluid. The nozzle42and the supply tube40may be a single, integral part or they may be connected by a substantially fluid-tight seal, such as a snap-fit connection, or other appropriate means. Additionally, sealing washers may be provided in order to more effectively form the fluid-tight seal between the nozzle42and the supply tube40.

The water cannon assembly14shown inFIG. 1includes various assembly components for assembling the previously-described components together. One such assembly component is a retainer ring44that fits over the outer face of the exterior portion26in order to secure the pivot joint socket22and the pivot joint18within the wall box10. The retainer ring14preferably is a C-shaped ring that forms a snap-fit connection with the wall box10, as will be discussed in further detail below with respect toFIG. 2.

Another such assembly component is a pivot joint clamping ring46that is preferably fastened to the wall box10in order to secure the retainer ring44and the pivot joint18in place. The pivot joint clamping ring46is preferably a closed ring that is fastened to the wall box10by appropriate fasteners, such as by fasteners47shown inFIG. 1. A cardon joint clamping ring48is also preferably fastened to the steering assembly34in order to hold the cardon joint36in place. The cardon joint clamping ring48is preferably fastened to the steering assembly34by appropriate fasteners50.

FIG. 2shows the water cannon assembly14mounted in a boiler wall52such that stream of cleaning fluid (generally indicated by arrow54) flows from the nozzle42along a water cannon assembly axis56and into the boiler interior volume58. More specifically, the supply tube40includes an interior surface53defining a conduit that carries the stream of cleaning fluid. In order to supply the stream of cleaning fluid to the boiler interior volume58, the pivot joint18includes an opening60adjacent to the boiler interior volume58.

FIG. 2shows the exterior portion26of the pivot joint socket22forming a substantially fluid-tight wall box seal62with the sealing portion20of the pivot joint18when the water cannon assembly14is in a first position, the operating position64. In order to assist in forming the wall box seal62, a spring63is preferably positioned between a flange on the steering tube32and the cardon joint36. The spring63applies a force on the steering tube32in a direction parallel with the water cannon axis56in a direction away from the wall box10. Therefore, the spring63causes the pivot joint18to press up against the interior portion24of the pivot joint socket22and improve the wall box seal62.

As discussed in the background section, it may be desirable to remove the water cannon assembly14from the boiler wall52for various reasons, such as maintenance. An assembly for removing the water cannon assembly14from the boiler wall52will now be discussed in more detail.

FIG. 2shows an aspirating device66connected to the outer surface of the steering tube in order to facilitate the removal of the water cannon assembly14from the boiler wall52. The steering tube32includes a plurality of aspirating openings68extending completely through the steering tube walls. The aspirating openings68are preferably angled with respect to the water cannon assembly axis56such that fluid flowing through the aspirating openings68flows towards the nozzle42.

The aspirating device66is located along the steering tube such that the aspirating openings68are enclosed by the aspirating device66. More specifically, the aspirating device66includes a chamber wall surface70that defines an aspirating chamber72, and the aspirating chamber72is aligned with the aspirating openings68. In order to form a fluid-tight seal around the aspirating chamber72, the aspirating device66preferably includes a plurality of sealing channels74that receive sealing members76.

FIG. 3shows an exploded view of one embodiment of the aspirating device66. The aspirating device66preferably includes two ring sections78,80that clamp together in order to form the aspirating chamber72. The aspirating chamber72preferably has a ring-shaped cross section in order to extend completely around the steering tube32. The sealing channels74also preferably have a ring-shaped cross section in order to extend completely around the steering tube32and in order to receive the curved sealing members76. The sealing members76are preferably comprised of an elastic material, such as rubber in order to effectively form a fluid-tight seal with the steering tube32.

The ring sections78,80are preferably clamped together by appropriate fasteners, such as the threaded fasteners82and the threaded receiving heads84shown inFIG. 3. More specifically, the first ring section78preferably includes a threaded opening86that forms a threaded-engagement with the threaded fastener82, and the second ring section80includes an opening88having a diameter larger than the outer diameter of the threaded fastener82. The threaded fastener82is configured to slide through the opening88in order to be received by a threaded opening90of the threaded receiving head84, which is located on the outer surface of the second ring section80. As shown inFIG. 3, the aspirating device66may include a plurality of threaded fasteners82and a plurality of threaded receiving heads84.

The aspirating device66also includes an air supply opening92that is in fluid connection with the aspirating chamber72. During operation of the aspirating device66, an aspirating fluid (such as air) that is supplied to the air supply opening92will flow into the aspirating chamber72, through the aspirating openings68, and into a conduit defined by the steering tube32.

Referring back toFIG. 2, when the water cannon assembly14is in operation, the stream of cleaning fluid substantially prevents boiler gasses from entering the water cannon assembly supply tube40. The aspirating device66substantially prevents these boiler gasses from entering the water cannon assembly14by providing the aspirating fluid flow through the aspirating openings68.

Therefore, once the aspirating device66is installed and an air flow is provided to the air supply opening92, the stream of cleaning fluid through the supply tube40may be discontinued and the supply tube40may be removed from the water cannon assembly14. The supply tube40is preferably disconnected from the steering tube32by removing a plurality of fasteners (not shown) that connects the collar portion94of the supply tube40to the cardon joint36. Once the fasteners are removed from the collar potion94, the supply tube40may be easily retracted from the steering tube32.

Once the supply tube40is removed from the steering tube32, the aspirating fluid flow from the aspirating device66will create a partial vacuum within the steering tube conduit96. More specifically, the angle and positioning of the aspirating openings68creates a funnel-like effect within the steering tube32and forces the aspirating fluid into the boiler interior volume58and prevents boiler gasses from escaping. The air flow from the aspirating device66also serves to cool the steering tube32and the pivot joint18.

In another example of alternative embodiments of the present invention, the assembly for removing the removable device includes an alternative aspirating device, or does not include an aspirating device. Particularly as used in connection with boilers having a minimal boiler interior volume pressure, or a negative internal volume pressure, an aspirating device may not be necessary in order to prevent the exchange of gasses between the boiler interior volume58and the ambient air. Furthermore, an alternative aspirating device may expel fluid into the removable device in a direction other than shown and described above. Additionally, an alternative aspirating device may prevent the exchange of gasses by a means other than injecting a fluid into the boiler interior volume58.

Referring now toFIG. 4, another component of the assembly for removing the water cannon assembly14from the boiler wall52is shown. More specifically, a steering tube plug98is inserted into the steering tube conduit96in order to form a substantially fluid-tight steering tube plug seal100. The steering tube plug seal100substantially prevents boiler gasses from entering the steering tube32through the pivot joint18. Therefore, once the steering tube plug98is inserted into the steering tube32, the aspirating device66may be removed from the water cannon assembly14.

The steering tube plug98includes a head portion102, a tail portion104, and a shaft portion106connecting the two respective portions102,104. The head portion102of the steering tube plug98preferably includes a larger diameter than the shaft portion106in order to form the steering tube plug seal100. The head portion102also preferably includes a seal ring108in order to more effectively form the steering tube plug seal100with the steering tube conduit96. The seal ring108is preferably located within a channel110formed in the head portion102of the steering tube plug98in order to hold the seal ring108in place. The channel110is preferably an indentation formed in the outer surface of the head portion102and has a cross-sectional shape that mates with the seal ring108.

The tail portion104of the steering tube plug98preferably includes a locking mechanism in order to secure the steering tube plug98in place. The locking mechanism112shown inFIG. 4includes a wedge assembly including an outer wall116that radially expands in order to form a frictional engagement with the steering tube32. More specifically, as a wing nut117is tightened, a conical wedge118is driven towards the head portion102of the steering tube plug98, thus causing the conical portion120of the conical wedge118to move further into the conical section122of the outer wall116. The radial force between the conical wedge118and the outer wall116substantially secures the steering tube plug98. The locking mechanism112may further include a rubber bellow119in order to prevent contaminants from entering the locking mechanism112and to protect the user from getting pinched by the moving components of the locking mechanism112. Any other appropriate alternative locking mechanisms may be used to secure the steering tube plug98.

AlthoughFIG. 4shows the steering assembly34and the cardon joint36still attached to the water cannon assembly14, it may be advantageous to remove one or both of these components34,36from the water cannon assembly14before inserting the steering tube plug98into the steering tube32. More specifically, the locking mechanism112may have a larger diameter than the cardon joint36, thus making removal of the cardon joint36difficult. Additionally, the locking mechanism112may interfere with the removal of the fasteners50that secure the cardon joint clamping ring48to the steering assembly34.

A portion a method of removing the pivot joint18from the boiler wall52will now be further discussed in more detail. Referring toFIG. 4, the fasteners47and the pivot joint clamping ring46are removed, exposing the retainer ring44. The retainer ring44may not be able to sufficiently hold the exterior portion26of the pivot joint socket22after the steering assembly is removed. Therefore, it is advantageous to connect a clamp assembly (not shown) to the pivot joint18after removing the pivot joint clamping ring46and before removing the steering assembly34.

The clamping assembly is preferably a metal plate having a notch in order to slide over the neck portion124of the pivot joint18. The clamping assembly is preferably mounted to the pivot joint18by a plurality of adjustable clamps that maintain the clamping assembly in a position a specific distance from the wall box10. More specifically, the adjustable clamps cause the clamping assembly to apply a force acting on the neck portion124of the pivot joint18in a direction perpendicular to and away from the wall box. The adjustable clamps are preferably threaded bolts extending through threaded portions of the clamping assembly and abutting the wall box10such that the slot portion of the clamping assembly exerts the force on the neck portion124.

Once the clamping assembly is installed, the retaining ring44and the exterior portion26of the pivot joint socket22prevent the pivot joint18from moving away from the boiler interior volume58, and the clamping assembly prevents the pivot joint18from moving towards the boiler interior volume58.

After the clamping assembly is in place, the steering assembly34and the cardon joint36may be removed. The cardon joint36is disconnected from the spring63, and therefore the wall box seal62would be more susceptible to leaking without the clamping assembly.

Due to the weight of the steering assembly34, it may be advantageous to use a hoist to stabilize the steering assembly34during its removal. Referring now toFIG. 5, once the steering assembly34has been removed, a pair of bridge extension feet126,128is preferably connected to the wall box10by a plurality of fasteners130. The bridge extension feet126,128extend substantially perpendicularly from the wall box10in order to facilitate the removal of the pivot joint18from the wall box10, as will be discussed in further detail below.

Next, the clamping assembly is preferably removed from the pivot joint neck portion124. In order to maintain the substantially fluid-tight seal between the interior portion24of the pivot joint socket22and the sealing portion20of the pivot joint18, the steering tube32is preferably manually pulled away from the boiler interior volume58with a force sufficient to maintain the wall box seal62. The manual force required to maintain the wall box seal62is generally equal to the gravitational force pulling on the steering tube32, and therefore it is a relatively low force.

Referring now toFIG. 7, a pivot joint adapter132is next preferably attached to the pivot joint socket22by fasteners134extending through openings136and threading into the exterior portion26of the pivot joint socket22. The pivot joint adapter132includes a central opening136having an inner diameter slightly larger than the outer diameter than the steering tube so that the steering tube32extends through the central opening136of the pivot joint adapter132. Once the pivot joint adapter132is connected to the pivot joint socket22, the central opening136of the pivot joint adapter132substantially prevents radial movement of the steering tube32, and thus provides enough support to counteract gravitational forces acting on the steering tube32. Therefore, the manual force applied to the steering tube32is no longer necessary to maintain the wall box seal62.

Referring back toFIG. 5, another component of the assembly for removing the water cannon assembly14from the wall box10is shown. More specifically, a sealing assembly146is coupled to the wall box10and forms a substantially fluid-tight seal with the pivot joint adaptor132, as will be discussed in more detail below. The sealing assembly146includes a sealing panel assembly138that is attached to the wall box10and a sealing collar assembly142that is connected to the sealing panel assembly138. The sealing panel assembly138is preferably located between the wall box10and the sealing collar assembly142.

The sealing panel assembly138forms a substantially water-tight seal140with the wall box10. Additionally, the sealing collar assembly142and the sealing panel assembly138preferably form a substantially fluid-tight seal144. The sealing panel assembly138and the sealing collar assembly are shown inFIG. 5as two, integral components. However, the sealing panel assembly138and the sealing collar assembly142may alternatively be formed by a single, unitary structure.

Referring now toFIG. 6, the details of the sealing panel assembly138and the sealing collar assembly142shown in this embodiment will now be discussed. The sealing collar assembly142includes an inner surface148configured to form a substantially fluid-tight seal with the pivot joint adapter132during removal of the pivot joint18from the wall box10, as will be discussed in further detail below. Therefore, the inner surface148of the sealing collar assembly142is preferably the same shape and size as the pivot joint adapter132.

The sealing collar assembly142also includes at least one release pin150athat is configured to disengage the retainer ring44such that the pivot joint socket22and the pivot joint18can be freely removed from the wall box10. The sealing collar assembly142shown inFIG. 6includes a second, a third, and a fourth release pin150b,150c,150d, where each respective release pin150(the reference number150is used to generally refer to the four release pins150a,150b,150c, and150d) cooperates to release the retainer ring44as desired.

More specifically, the release pins150each have locked position where the retainer ring44is able to lock the pivot joint socket22to the wall box10as shown inFIG. 2, and an unlocked position where the retainer ring44is disengaged. The release pins150a,150b,150cshown inFIG. 6are each respectively in the locked position. Conversely, the release pin150dhas been slidably moved towards the sealing panel assembly138in order to at least partially disengage the retainer ring44. As shown inFIG. 1, the retainer ring44includes a slot154in order to allow the retainer ring diameter to contract, and thus allowing the retainer ring44to disengage.

In order to facilitate the sliding movement of the release pins150, the sealing collar assembly142includes a plurality of channels152that slidably receive the respective release pins150, and the sealing panel assembly138includes a plurality of openings (not shown) aligned with each of the respective channels152in order to permit the respective release pins150to extend there through and engage the retainer ring44.

Referring now toFIG. 2, the wall box10includes a guide channel156for receiving a portion of the retainer ring44and preventing longitudinal of such (where longitudinal motion is defined as being generally perpendicular with the wall box10face). The pivot joint socket22likewise includes a guide channel158to prevent the pivot joint socket22from moving in the longitudinal direction. When one of the respective release pins150, such as the release pin150d, is moved to its open position, the diameter of the retainer ring44decreases and the retainer ring44is at least partially unseated from the guide channel156. Once each of the respective release pins150has been moved to the open position, the retainer ring44is preferably completely unseated from the guide channel156, releasing the retainer ring44and the pivot joint socket22from the wall box10.

In order to promote a smooth and effective release of the retainer ring44, some or all of the release pins150may include a tapered end (not shown) that engages the retainer ring44. The tapered end may have a conical, a rounded, or any other appropriate shape for promoting radially inward movement of the retainer ring44(where the radial direction is generally parallel to the wall box10face).

The sealing panel assembly138shown inFIG. 6will now be discussed in more detail. The sealing panel assembly138includes a sealing panel base portion159that is fastened to the wall box10via a plurality of fasteners160in order to form the seal140. As shown inFIGS. 2 and 6, the fasteners140extend through openings (not shown) in the wall box10and into a chamber162defined by the wall box walls. The chamber162preferably receives sealing air that flows from the chamber162into the boiler interior volume58via a plurality of seal air openings164(shown inFIG. 2) adjacent to the pivot joint interior portion24. During operation of the water cannon assembly14the sealing flow substantially prevents boiler gasses from entering the chamber162through the seal air openings164due to relatively high velocity of the sealing flow. Furthermore, during removal of the water cannon assembly14from the wall box10, the sealing flow is able to flow through the wall box openings once the fasteners140are removed. Therefore, while the fasteners140are removed, it is desirous to maintain a relatively high velocity sealing flow in order to prevent boiler gasses from exiting the wall box.

Referring back toFIG. 6, the sealing panel assembly138preferably includes a pair of sealing panels166,168configured to slidably move with respect to the sliding panel base portion159and selectively engage each other in order to form a substantially fluid-tight sealing panel seal170(shown inFIG. 8). In order to more effectively form the sealing panel seal170, the respective sealing panels166,168preferably include engaging surfaces such as mating edge portions172,174extending from the respective sealing panels166,168in a direction substantially parallel to each other. The mating edge portions172,174may further include a snap-tight engagement or other sealing mechanism in order to improve the sealing panel seal170. Although the sealing panel assembly138shown in the figures includes a pair of sealing panels166,168, any appropriate number of sealing panels may be used, such as a single sealing panel.

The sealing panel assembly138shown inFIG. 6preferably includes upper and lower track portions176,178that slideably receive the sealing panels166,168. The track portions176,178are preferably parallel to each other and are located a distance from each other that is approximately equal to the height of the sealing panels166,168in order to form a seal with the panels166,168. The track portions176,178shown inFIG. 6are flanges extending perpendicularly from the rear surface of the sealing panel assembly138and preferably have a relatively low-friction engagement with the sealing panels166,168.

The track portions176,178shown inFIG. 6have a width80substantially equal to the thickness182of the respective sealing panels66,68in order to minimize unwanted movement of the sealing panels166,168in a direction perpendicular to the faces of the sealing panels166,168. Alternatively, the sealing panel assembly138may include track portions that prevent the sealing panels166,168from moving in a direction perpendicularly to their faces, such as by L-shaped flanges (not shown) extending around the edges of the panels166,168.

The sealing panel assembly138preferably includes an adjustment assembly for adjusting the respective positions of the sealing panels166,168as desired. The adjustment assembly shown inFIG. 6includes a cylindrical knob184extending from each of the sealing panels166,168in a direction substantially perpendicular to the sealing panel faces186. The cylindrical knobs184are aligned with and extend through receiving slots188formed in the base portion159of the sealing panel assembly138in order to allow the sealing panel assembly user to adjust the position of the sealing panels166,168from the front side190of the base portion159. Also shown inFIG. 6, the cylindrical knobs184are preferably coupled with locking handles192that perform two functions, providing a conveniently-sized handle to move the sealing panels166,168, and providing a locking mechanism to lock the sealing panels166,168in place when desired.

The locking handles192preferably include a central bore configured to receive the cylindrical knobs184, and more preferably include internal threads within the central bores in order to form a threaded engagement with external threads of the cylindrical knob. Thus, the sealing panels166,168may be locked in a desired position by turning the locking handles192in a specified direction (such as in the clockwise direction as shown inFIG. 6), thereby causing a frictional engagement between the locking handle192and the base portion159and another frictional engagement between the sealing panels166,168and the base portion159. Alternatively, any appropriate locking mechanism may be used.

Similarly, the sealing panels166,168may be released from the locking position by turning the locking handles192in the opposite direction (counter-clockwise), thereby releasing the locking handles192and the sealing panels166,168from their respective frictional engagements with the base portion159.

Referring now toFIG. 7, the components of a jack assembly194for aiding in the removal of the water cannon assembly14from the wall box10are shown. The jack assembly194mounts to the bridge extension feet126,128and selectively engages the pivot joint adapter132in order to remove the pivot joint18from the wall box opening16. Alternatively, the pivot joint18may be removed by hand instead of utilizing a jack assembly.

The jack assembly194shown inFIG. 7includes a retracting device, such as a jack screw196that selectively engages the pivot joint adapter132by an appropriate connection, such as a tab-slot connector. The jack screw196shown inFIG. 7includes a plurality of tabs (not shown) located adjacent to an en198of the jack screw, which are configured to slide into L-shaped receiving slots200located on the pivot joint adapter132. During engagement between the jack screw196and the receiving slots200, the tabs, which are preferably located within a hollowed-out cavity defined by the jack screw198, are first inserted into a first portion of the receiving slots100that extends generally parallel to the jack screw198. Next, the pivot joint adapter132and the jack screw196are rotated with respect to each other such that the tabs slide into a second portion of the receiving slots200that is perpendicular to the first portion. The second portion of the receiving slot200may further include an enlarged diameter portion in order to prevent the jack screw196from rotating with respect to the pivot joint adapter132.

The jack assembly194shown inFIG. 7includes components for causing translational movement of the jack screw196and the pivot joint adapter132, thus removing the pivot joint18from the wall box opening16. More specifically, the jack screw196preferably includes external threads202and a pivoting collar204that receives the jack screw196in a threaded engagement. Furthermore, a support bridge206extends between the respective bridge extension feet126,128in a direction substantially perpendicular to the jack screw196.

The support bridge206is preferably secured to the respective bridge extension feet126,128by a plurality of fasteners207that are received by threaded openings209. Also, the support bridge206and the bridge extension feet126,128preferably include locating pins211and locating openings213for properly aligning the support bridge206with the respective bridge extension feet126,128during assembly of the respective components.

As shown inFIG. 7, the jack screw196extends through an opening208in the support bridge having an inner diameter larger than the outer diameter of the jack screw196such that the jack screw196freely slides through the opening208. On a first side of the support bridge206, such as the bottom side210shown inFIG. 7, the external threads202of the jack screw196engage a retaining ring212via a threaded engagement. Additionally, on the other side of the support bridge206, such as the top side214shown inFIG. 7, the external threads202of the jack screw196form a threaded engagement with internal threads216of the pivoting collar204. As shown inFIG. 7, a thrust washer218may be located between the retaining ring212and the support bridge206on the bottom side210and a thrust washer220may be located between the support bridge206and the pivoting collar204on the top side214.

As the pivoting collar204is rotated, radially-acting forces are applied to the jack screw196by the threaded engagement between the respective components196,204. As a result of the radially-acting forces, the jack screw196has a tendency to rotate in-place instead of moving axially (where axial movement is generally indicated by arrow222shown inFIG. 7). Therefore, the jack assembly194preferably includes an anti-rotational mechanism in order to substantially prevent rotational movement of the jack screw196and therefore convert rotational movement of the pivoting collar204into axial movement of the jack screw196.

FIG. 7shows an anti-rotation device224that is fastened to the support bridge206adjacent to the jack screw196by a pair of fasteners226. The jack screw196shown inFIG. 7also preferably includes an anti-rotational channel extending along the outer surface of the jack screw196in a direction substantially parallel to the axial direction222. The anti-rotational channel, which is not visible inFIG. 7, but the location of which is generally indicated by reference number228, receives a portion of the anti-rotational device224in order to allow axial movement between the anti-rotational device224and the jack screw196, but to prevent rotational movement between the respective components224,196.

In order to form a mating engagement between the anti-rotational device224and the jack screw196while minimizing frictional forces between the two respective components, the anti-rotational device preferably includes an appendage230extending from the anti-rotational device224in a direction substantially perpendicular to the anti-rotational channel228. The width of the anti-rotational channel228and the width of the appendage230are preferably substantially equal. More preferably, the width of the anti-rotational channel is slightly greater than the width of the appendage230.

During operation of the jack assembly194, the pivoting collar204is rotated in a first direction, such as clockwise, in order to cause relative rotational movement between the pivoting collar204and the jack screw196. Due to the relative rotational movement between the pivoting collar204and the jack screw196, axial movement results between the two components204,196. The direction of the axial movement will depend on the thread orientation of the respective components204,196. However, in one configuration a clockwise rotation of the pivoting collar204causes the jack screw196to move away from the wall box10.

In order to facilitate rotation of the pivoting collar204, the pivoting collar204preferably includes a flange232extending from the outer surface of the pivoting collar204in a direction substantially perpendicular to the axial direction222. In order to further facilitate rotational movement of the pivoting collar204, a handle234preferably extends from the flange232. The handle234may have any appropriate shape, but it preferably has a shape that is easy to grip for a typical jack assembly operator.

Referring now toFIG. 5, the jack assembly194is connected to the pivot joint adapter132(as shown inFIG. 7), and the pivot joint adapter132is connected to the pivot joint18. In the configuration shown inFIG. 5, the pivot joint18is in the first position (the operational position64) in order to form the substantially fluid-tight wall box seal62. Also shown inFIG. 5, the jack screw196is preferably in a fully-extended position such that the jack screw196extends beyond the pivoting collar204by a first distance238.

The release pins150a,150dshown inFIG. 5are preferably in a closed position when the pivot joint18is in the operational position64such that the retainer ring44is substantially located within the guide channel156(shown inFIG. 2). Furthermore, the locking handles192are preferably fully-extended away from the sealing collar assembly142such that the sealing panels166,168are in an open position.

Referring now toFIG. 8, the pivot joint adapter132and the pivot joint18have been retracted from the wall box opening16such that the pivot joint18is in a second position, a maintenance position240. Also, as shown inFIG. 8, the jack screw196has moved away from the wall box10such that the jack screw196extends a second distance242beyond the pivoting collar204. As shown inFIGS. 5 and 8, the second distance242is greater than the first distance238.

As shown inFIG. 8, the release pins150a,150dare preferably in an open position such that the retainer ring44has been disengaged from the wall box opening16, thereby releasing the pivot joint18from the wall box10. Furthermore,FIG. 8shows the locking handles192in a position adjacent to the sealing collar assembly142such that the respective sealing panels166,168are in the closed position in order to form the sealing panel seal, generally indicated by reference170. The sealing panel seal170substantially prevents boiler gasses from escaping through the wall box opening16while the pivot joint18is in the maintenance position240.

The wall box10, the water cannon assembly14, the sealing assembly146, and the jack assembly194are preferably comprised of a high-temperature-resistant steel such RA-330 or an alloy such as Inconel 601, but other appropriate materials may be used.

The assembly for removing the water cannon assembly14from the wall box10described above and shown in the figures includes various embodiments of the present invention. However, the present invention may include various additional components, various alternative components, or fewer components than those described and shown above.

Another portion of a method of removing the pivot joint18from the boiler wall52will now be further discussed in more detail. Once the pivot joint adaptor132is connected to the pivot joint18, the sealing panel assembly146is connected to the wall box10such that the sealing panels166,168engage the wall box10in order to form the seal140. The sealing collar assembly142is positioned such that the inner surface148of the sealing collar assembly142is aligned with the pivot joint132. The sealing collar assembly142is then fastened to the sealing panel assembly138via fasteners.

After the sealing assembly146is connected to the wall box10, the jack assembly194is connected to the bridge extension feet126,128and the jack screw196is coupled to the pivot joint adaptor132as described above. Next, the release pins150are moved to an open position to collapse the retaining ring44and release the pivot joint18and the pivot joint socket22from the wall box opening16.

Next, the pivot joint18is removed from the wall box opening16by rotating the jack assembly handle234in a clockwise direction until the pivot joint18is positioned such that the sliding panels166,168are located between the pivot joint18and the wall box opening16, as shown inFIG. 8. This position is the maintenance position240.

Once the pivot joint18is in the maintenance position240, the locking handles192are rotated counter-clockwise, thereby loosening the frictional engagement between the locking handles192and the sealing panel base portion159. Then, the sliding panels166,168are closed by sliding the locking handles192towards the sealing collar assembly142until the panels166,168engage each other and form the sealing panel seal170. The locking handles192are then tightened, and the sealing panel seal170is sufficient to seal the wall box opening16from the ambient air.

Once the sealing panel seal170is engaged, the handle234is further rotated clockwise until the pivot joint adaptor132is completely removed from the sealing collar assembly142. At this point, the sealing panel seal170is directly separating the boiler gases from the ambient air. The support bridge206, which is preferably still engaged with the jack screw196, is next removed from the bridge extension feet126,128in order to expose the pivot joint18and the retainer ring44. The pivot joint18is then removed from the pivot joint adaptor132.

It may be advantageous to install a boiler plug (not shown) into the wall box opening16in order to provide a more effective seal than the sealing panel seal170. The boiler plug is preferably comprised of a high-temperature-resistant steel such RA-330 or an alloy such as Inconel 601, but other appropriate materials may be used. The boiler plug is preferably disc-shaped having a circular outer surface for mating with the wall box opening16. The boiler plug preferably has a smooth outer surface with a diameter substantially equal to that of the pivot joint socket22.

Next, the retainer ring44is positioned near the bottom of the pivot joint adaptor132as shown inFIG. 7. The boiler plug is then positioned such that the retainer ring44is between the pivot joint adaptor132and the boiler plug. Next, the boiler plug is connected to the pivot joint adaptor132by the fasteners134in a manner similar to the connection between the pivot joint adaptor132and the pivot joint socket22.

The support bridge206, which is still engaged with the jack screw and pivot joint adaptor132, is then re-connected to the bridge extension feet126,128such that the pivot joint adaptor132is aligned with the sealing collar assembly142. Next, the handle234is rotated counter-clockwise until the pivot joint adaptor132is located within the sealing collar assembly142in order to form a substantially fluid-tight seal between the pivot joint adaptor132and the inner surface148of the sealing collar assembly142.

Once the pivot joint adaptor132and the boiler plug have been inserted into the sealing collar assembly142, the sealing panels166,168may be re-opened by sliding the locking handles192away from the sealing collar assembly142. The jack assembly handle234is then preferably rotated counter-clockwise until the boiler plug is located within a hard stop of the wall box opening16. The release pins150are then moved to the closed position so the retainer ring44can snap into engagement in the guide channel156of the wall box10.

Next, the fasteners207are removed so the support bridge206is released from the bridge extension feet126,128. The jack screw196and support bride206are then rotated counter-clockwise to release engagement from the pivot joint adaptor132. The jack assembly194is then completely removed from the wall box10, and the pivot joint adaptor132is removed from the sealing collar assembly142by hand. Then, the sealing assembly146is removed from the wall box10, exposing the boiler plug and the retainer ring44. Finally, the pivot joint clamping ring46is fastened to the wall box10in order to further secure the retainer ring44and the boiler plug in place.

In order to re-install the water cannon assembly14, a process similar to that described above, but performed in reverse, is preferably utilized.

Referring now toFIG. 9, an alternative assembly300for removing the water cannon assembly14from the wall box10is shown. The assembly300primarily includes a sealing box302cooperating with the wall box10to define a sealing chamber304and an access assembly306that provides access to the sealing chamber304. The sealing chamber304encompasses a portion305of the water cannon assembly14and forms a substantially fluid tight seal with the wall box10to seal-off the portion305of the water cannon assembly from ambient air307and to permit removal and/or maintenance of the water cannon assembly14while the boiler is in use.

The sealing box302includes a flange303that is bolted to the wall box10to form the seal between the respective components303,12. Furthermore, the sealing box302is large enough to encompass the portion305of the water cannon assembly14, which includes the pivot joint18, the steering tube32, and the steering tube plug98in the design shown inFIG. 9. As described above in more detail, the pivot joint18, the steering tube32, and the steering tube plug98cooperate to form a seal with the wall box opening16to prevent hot combustion gases from escaping from the boiler. Therefore, the sealing box302is connected to the wall box10while the respective components18,32,98are still cooperating to form the seal. Additionally, the top portion of the sealing box302includes a viewing portion, such as a transparent panel309, to permit a user to view inside the sealing box302. In an alternative design, the sealing box302includes an optical device, such as a video camera or an infrared imaging device, to permit the user to view inside the sealing box302.

The access assembly306provides access to the water cannon assembly14without disrupting the fluid tight seal within the sealing chamber304. For example, the access assembly306permits the user to perform maintenance on the portion305of the water cannon assembly14and/or remove the portion305of the water cannon assembly14without permitting the hot combustion gases to escape from the boiler. The access assembly306shown in the drawings includes a pair of protective sleeves308a,308bextending into the sealing chamber304via an access opening310in the sealing box302to facilitate such operations. For example, the protective sleeves308a,308bare configured to form a sleeve seal312with the sealing box302at a proximal end316thereof and include glove portions318at a distal end320thereof for handling components within the sealing box302. The protective sleeves308a,308bare preferably made of a thermally insulated material to protect the user's arms and hands from the hot boiler gases. Furthermore, the protective sleeves308a,308bpreferably include stiffening components embedded therein to prevent the protective sleeves308a,308bfrom collapsing inward onto the user's arms and hands due to a potentially increased pressure within the sealing chamber304.

The assembly300further includes a plug314configured to be received within the wall box opening16after the portion305of the water cannon assembly14has been removed from the wall box opening16. For example, the plug314has a diameter generally equal to that of the wall box opening16so as to form a generally fluid-tight seal therewith after the portion305of the water cannon assembly14has been removed. The plug314is preferably placed within the sealing box302before it is mounted to the wall box10so that the user has access to the plug314during the above described maintenance and/or component change. More specifically, the user first disconnects and removes the portion305of the water cannon assembly14from the wall box10and places the portion305of the water cannon assembly14on the floor of the sealing box302. At this time, gasses from the boiler are able to enter the sealing chamber304, thereby potentially heating the protective sleeves308a,308b. However, the boiler gases are preferably generally prevented from escaping from the sealing chamber304and are preferably generally prevented from excessively heating the user's arms and hands, as described above in more detail. Next, the user inserts and secures the plug314into the wall box opening16and forms the seal; thereby permitting the removal of the assembly300from the wall box10.

The assembly300may be used in conjunction with, or as a replacement for, the assembly for removing water cannon assembly16that is disposed with respect toFIGS. 1-8. For example, the assembly300may be used in conjunction with, or as a replacement for, the following: the aspirating device66, the steering tube plug98, the sealing assembly146, and the jack assembly194.

In an alternative design, the assembly300includes one or more mechanically-controlled or electronically-controlled robotic arms for facilitating the above-described operations. The robotic arms are preferably made of materials capable of performing these operations under the relatively high-temperature, high-pressure conditions described herein. This robotic arms may be used in conjunction with, or as a replacement for, the protective sleeves308a,308b.

It is therefore intended that the foregoing detailed description be regarded as illustrative rather than limiting, and that it be understood that it is the following claims, including all equivalents, that are intending to define the spirit and scope of this invention. More particularly, the assembly and method described are merely an exemplary assembly and method, and they are not intended to be limiting. Many of the steps and devices for performing the steps described above may be eliminated or replaced by alternative steps and devices.