Gasket arrangement for a boiler protruding bar and method of operating said gasket arrangement
Patent Information
- Application Number
- JP2024532208
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2021-12-01
- Filing Date
- 2022-11-30
- Publication Date
- 2025-12-02
AI Technical Summary
Existing probes for measuring recovery boilers face challenges in withstanding harsh conditions and sealing gaps between the protruding bar and the combustion chamber, leading to gas leakage and exposure to harmful substances.
A sealing device with a gasket that slides around the protruding bar, attached to the chamber wall via magnets, fastening elements, or springs, ensuring sealing during insertion and retraction, and a hatch mechanism to minimize unsealed time.
Effectively seals the gap between the protruding bar and the chamber, reducing gas leakage and exposure to harmful substances during the loading and unloading process.
Smart Images
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Abstract
Description
[Technical field]
[0001] The present invention relates to a gasket for a protruding bar of a boiler, preferably the protruding bar having a probe for automatic measurement of recovery boilers. [Background technology]
[0002] Recovery boilers burn dried black liquor as fuel. The liquid contains chemicals that are recovered after combustion and other reactions in the boiler. The operating conditions inside a liquid combustor are hot and corrosive, and the flue gases are highly polluted and contain harmful substances. Any openings must be blocked from leaking gases from inside the boiler room to the outside.
[0003] Some probes cannot withstand the conditions for long periods or are not intended to remain in the boiler room for long periods. They are often arranged to be inserted from time to time into the boiler room using a protruding bar. An example of such a protruding measuring bar is described in publication WO2020260762. A similar protruding bar is, for example, a sootblowing bar for any type of boiler.
[0004] The automatic operation of the protruding measuring bar, which is temporarily inserted into the combustion chamber, should seal the leakage of gases and particles from inside the combustion chamber to the outside space. Flue gases, especially in recovery boilers, are dense fumes containing harmful and sticky substances. Due to the thermal expansion of the combustion chamber walls, it is difficult to use strict tolerances on the position and dimensions of the wall openings. In fact, it is not possible to provide a sufficiently narrow gap between the protruding bar and the opening in the boiler room wall. The gasket for sealing the gap should be able to seal the gap not only when the protruding bar is fully inserted into the combustion chamber, but also during the process of the protruding bar entering the combustion chamber. Thereby, the time for leakage through the gap is minimized. [Prior art documents] [Patent documents]
[0005] [Patent Document 1] WO2020260762 Summary of the Invention [Problem to be solved by the invention]
[0006] The object of the present invention is to provide a reliable sealing device for the protruding bars of a combustion chamber boiler, and a method for operating the same. These and other objects which will become apparent from the following summary and description are achieved by the device and method defined in the appended claims. [Means for solving the problem]
[0007] A sealing device for a protruding bar of a boiler has a gasket slidably disposed around the protruding bar to seal the gap between the protruding bar and the wall of the combustion chamber. The sealing device also includes means for attaching the gasket to the wall of the combustion chamber while the protruding bar is inserted into the combustion chamber. The gasket detaches from the wall when the protruding bar retracts from the combustion chamber. Thus, the gap around the protruding bar is sealed most of the time during the insertion and removal process.
[0008] The gasket is preferably attached to the wall of the combustion chamber by at least one magnet attached to the gasket. The gasket can also be attached to the wall of the combustion chamber by at least one fastening element moved by an actuator or a spring. The fastening element can have a hook-like shape or be attached by friction to the gasket. The protruding bar preferably has a protrusion that connects to the gasket and moves the gasket away from the wall of the combustion chamber while the protruding bar retracts from the combustion chamber. The gasket may be attached to the wall of the combustion chamber by a spring that presses it against the wall. The other end of the spring is fixed or at least abuts against an object in the form of a protruding bar or a handling device. The other end of the spring may be fixed to the gasket so that the gasket moves away automatically even without the protrusion of the protruding bar. The method should also work in manual operation without a handling device that moves the protruding bar.
[0009] The opening of the combustion chamber is covered by a hatch that is opened by an opening actuator just before the protruding bar enters the combustion chamber. To minimize the unsealed time, the hatch is closed immediately after the protruding bar is retracted from the combustion chamber.
[0010] The invention will now be described in more detail with reference to the accompanying drawings. [Brief description of the drawings]
[0011] [Figure 1] FIG. 1 illustrates a preferred embodiment of the present invention in which the gasket is attached to the wall of the combustion chamber by a magnet. [Diagram 2] FIG. 2 shows an embodiment of the invention in which the gasket is attached to the wall of the combustion chamber by fastening elements. [Diagram 3] FIG. 1 shows an embodiment of the present invention in which the gasket is attached to the wall of the combustion chamber by a spring on a protruding bar. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0012] FIG. 1 shows a preferred embodiment of a sealing device comprising a gasket 2, which is arranged around an ejection bar 1 and is attached to the wall 4 of a combustion chamber 3 of a boiler by means of a magnet 8 attached to the gasket 2. In this case, the ejection bar 1 is for measuring carryover particles from the flue gases of a recovery boiler. The ejection bar 1 is inserted into the combustion chamber 3 through an opening 5 in the wall 4. The insertion and removal process is performed by a handling device 10. The handling device 10 operates on a platform 11. The handling device 10 can be a programmable manipulator, such as a robot, or can be operated by a pressure cylinder or electromechanically. The handling device 10 can perform other handling operations besides the insertion and removal process. Just before the insertion, an opening actuator 7 opens the hatch 6 covering the opening 5. The operations necessary to perform the programmed tasks are controlled, for example, by a controller of the handling device 10 or by a controller of the boiler.
[0013] The gasket 2 may include a metal plate and a refractory cover on the combustion chamber side of the plate. The gasket 2 should match the shape of the protruding bar while having a suitable gap between them, so that the gasket 2 can still slide freely over the protruding bar 1. Before the protruding bar 1 enters the combustion chamber 3, the gasket 2 is first roughly positioned against the protruding bar 1. When the protruding bar 1 enters the interior of the combustion chamber 3 and the gasket contacts the wall 4, the magnet 8 attaches the gasket 2 to the wall 4. When the measurement cycle is finished, the protruding bar 1 retracts. At that time, the protrusion 9 of the protruding bar 1 separates the gasket 2 from the wall 4. The protrusion 9 can also be a shoulder of the protruding bar 1. After the protruding bar 1 retracts, the opening actuator 7 closes the hatch 6. In this case, the thin end of the protruding bar 1 that enters the combustion chamber 3 is for collecting the carryover particles to be measured. Therefore, neither the gasket 2 nor the wall 4 should contact the carryover collection area 12. Thus, during the insertion and removal process, the area between the outer ends of the projections 9, the ejection bar 1, is not temporarily sealed by the gasket 2.
[0014] FIG. 2 shows an embodiment of the sealing device, in which the gasket 2 is attached to the wall 4 of the combustion chamber 3 by at least one, preferably at least two, fastening elements 13. The fastening elements 13 can hold the gasket 2 attached to the wall 4 by friction or can have a hook-like shape for attachment. In particular in the case of a hook-like shape, a holding actuator 14 should be used to open and close the fastening elements 13. Instead of the actuator 14, a spring can also be used to press the fastening elements 13 against the gasket 2, generating a holding force by friction. Particularly in the case of the mounting type shown in FIG. 3, another protrusion 9 of the protruding bar 1 on the side opposite the gasket 2 can press the gasket 2 between the spring-activated frictional fastening elements 13.
[0015] Figure 3 shows an embodiment of the invention, in which the gasket 2 is attached to the wall of the combustion chamber by means of a spring 15. The gasket 2 is pressed against the wall 4 of the combustion chamber 3 by means of the spring 15. The inner end of the spring 15 is connected to the protruding bar 1 or to a handling device 10. The spring is preferably fixed to the gasket. If the gasket 2 is neither fixed to the spring 15 nor to the protruding bar 1 or to the handling device 10, the projections 9 at the outer end of the protruding bar 1 can make the gasket untouched when the protruding bar 1 retracts. The attachment methods shown in connection with figures 1 to 3 can be combined with each other.
Claims
1. 1. A sealing device for a protruding bar of a boiler, the protruding bar being arranged to enter the combustion chamber of a boiler through an opening in a wall of the combustion chamber, the protruding bar being attached to a handling device, the sealing device comprising: a gasket arranged around the protruding bar to seal a gap between the protruding bar and the wall of the combustion chamber, the gasket thereby being configured to keep the gasket attached to the wall of the combustion chamber while the protruding bar is fully inserted into the combustion chamber, and for at least a portion of the time the protruding bar enters the combustion chamber and at least a portion of the time the protruding bar retracts from the combustion chamber.
2. 2. The sealing device according to claim 1, wherein the gasket (2) is attached to the wall (4) of the combustion chamber (3) by means of at least one magnet (8) attached to the gasket (2).
3. 2. The sealing device according to claim 1, wherein the gasket (2) is attached to the wall (4) of the combustion chamber (3) by at least one fastening element (13) actuated by a holding actuator (14) or a spring.
4. 2. The sealing device according to claim 1, wherein the gasket (2) is attached to the wall (4) of the combustion chamber (3) by a spring (15) on the protruding bar, preferably the spring (15) being fixed to the gasket (2).
5. 3. The sealing device according to claim 2, wherein the protruding bar (1) has a protrusion (9) or elbow that connects to the gasket (2) and moves the gasket (2) away from the wall of the combustion chamber (3) while the protruding bar (1) is retracted from the combustion chamber (3).
6. 2. The sealing device according to claim 1, wherein the gasket (2) comprises a metal plate and a fire-resistant cover on the combustion chamber (3) side of the plate.
7. 2. The sealing device of claim 1, wherein the boiler is a pulp mill recovery boiler.
8. 1. A method of operating a sealing device for a protruding bar (1) of a boiler, wherein the protruding bar (1) is arranged to enter a combustion chamber (3) of the boiler through an opening (5) in a wall (4) of the combustion chamber (3), characterized in that a gasket (2) is arranged around the protruding bar (1) to seal a gap between the protruding bar (1) and the wall (4) of the combustion chamber (3), so that the gasket (2) adheres to the wall (4) of the combustion chamber (3) while the protruding bar (1) enters the combustion chamber (3) and releases from the wall (4) of the combustion chamber (3) when the protruding bar (1) retracts from the combustion chamber (3).
9. 9. The method according to claim 8, wherein the gasket (2) is attached to the wall (4) of the combustion chamber (3) by means of at least one magnet (8).
10. 9. The method according to claim 8, wherein the gasket (2) is attached to the wall (4) of the combustion chamber (3) by means of at least one fastening element (13) actuated by a holding actuator (14) or a spring.
11. 9. The method according to claim 8, wherein the gasket (2) is attached to the wall (4) of the combustion chamber (3) by means of the protruding bar (1) or a spring (15) on the protruding bar (1) connected to a handling device (10).
12. 9. The method according to claim 8, wherein the opening (5) is covered by a hatch (6) that is opened by an opening actuator (7) before the protruding bar (1) enters the combustion chamber (3) and that is closed after the protruding bar (1) is retracted from the combustion chamber (3).
13. 9. The method of claim 8, wherein the boiler is a pulp mill recovery boiler.