KR20140097448A - Method to repair compromised inlet outlet piping - Google Patents

Abstract

Pipe rupture in a furnace cooling stove is a common failure mechanism. The present invention provides a repair method for a cooling stove (30) used in a furnace, wherein the cooling stove (30) comprises a compartmentalized stave inflow / outflow pipe (27), the method comprising: inserting a rigid pipe (1) into a compartmental stave inlet / outlet pipe (27) to form a first annular portion (28); Expanding the bladder (20) arranged in the cooling stave (30) and the inner pipe (1); Injecting a first non-cured epoxy material into the first annular portion 28; Curing the first non-cured epoxy; And removing the bladder (20).

Description

[0001] METHOD TO REPAIR COMPROMISED INLET OUTLET PIPING [0002]

The present invention relates to a repair method for a cooling stove used in a furnace, the present invention being based on U.S. Patent Application No. 61 / 567,395, filed December 6, 2011, Which is incorporated herein by reference.

The cooling stave of the blast furnace is used to protect and cool the furnace shell and to support the brick lining refractory material and maintain proper furnace morphology. In operation, the heat of the refractory material is transferred to the cooling stave base, which transfers this heat to the pipe containing the cooling water. The cooling water drops heat from the furnace. One failure mode occurs when the pipeline fractures under a heat load.

Since pipe rupture is common, several existing methods have been developed to reestablish cooling power on the stave. These methods include blowing nitrogen through the stave, grouting the corrugated metal hose through the entire stave circuit and grouting with a low-conducting grout, Drilling through blast furnace shells and staves to install a cigar cooler or grouting the inflow without cooling. These methods do not provide efficient cooling means. Using these conventional methods, high stresses in the stave over time can cause further destruction of the stave. Such breakage may include an inlet / outlet pipe completely ruptured from the stave, stave face washing, stave cupping or curving, and an anchor bolt exiting the stave, .

A first aspect of the invention describes a repair method for a cooling stave used in a furnace having a stave inlet / outlet pipe associated with a cooling pipe in the cooling stove , The method comprising: inserting a rigid pipe into a compartmentalized stave inlet / outlet pipe to form a first annulus; Expanding the bladder arranged in the cooling stave and the inner pipe; Injecting a first non-cured epoxy material into the first annular portion; Curing the first non-cured epoxy; And removing the bladder. In a preferred embodiment, the first end of the inner tube in the distal position relative to the cooling stave further comprises means for injecting the first non-curing epoxy into the first annulus, The second end of the proximal inner tube for the second non-cured epoxy further comprises means for draining the air that has been displaced while the first non-cured epoxy is being injected into the first annular portion. In a preferred embodiment, the repair method comprises the steps of: providing an external pipe external to the refined stave inlet / outlet pipe to form a second annular portion; Injecting a second non-cured epoxy material into the second annular portion; And allowing the second non-cured epoxy material to cure. In a preferred embodiment, the first and second non-cured epoxies are cured concurrently. In a preferred embodiment, the first non-cured epoxy is cured before the second non-cured epoxy is cured. In a preferred embodiment, the first end of the outer tube in the distal position relative to the cooling stave further comprises means for injecting the second non-cured epoxy into the second annular portion, wherein the proximal position Further comprising a boot configured to define a seal with the cooling stave and the outer tube, the second end of the outer tube being in open communication with the second annular portion open communication aperture.

A second form of the invention describes a repair method for a cooling stove used in a furnace which comprises rethreading a hole in a cooling stave formed after removal of the compartmental stave inlet / step; Mounting a new inlet / outlet pipe; Inserting an internal rigid pipe into the new stave inlet / outlet pipe to form an annulus; Expanding the bladder within the cooling stave and the inner pipe; Injecting a non-cured epoxy material into the annular portion; Curing the non-cured epoxy; And removing the bladder.

A third form of the invention describes a repair system kit for a cooling stove used in a furnace comprising an expansion bladder, an internal rigid pipe, a grout inlet, and a vent tube And a stave inlet / outlet pipe. In a preferred embodiment, the repair system kit further comprises a concentric outer pipe and a flexible rubber seal.

Figure 1 illustrates embodiments of elements in accordance with an aspect of the present invention.
Figure 2 illustrates additional embodiments of the elements of the present invention.
Figure 3 illustrates another form of the invention.
Figure 4 illustrates a conventional stave failure mechanism.
Figure 5 illustrates a conventional stave failure mechanism.
Figure 6 illustrates a conventional stave failure mechanism.

The following detailed description is set forth with reference to the accompanying drawings and embodiments which form a part hereof, and in which is shown by way of illustration only specific embodiments in which the subject of the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the above-described embodiments, and it is to be understood that other embodiments may be used and that these configurations or logical variations are possible without departing from the scope of the present invention. It will be possible. These embodiments of the present invention are not limited in scope to the concept of the invention in any way unless the scope of the present specification is limited to any single invention or in fact only one or more concepts are described, quot; invention ". Accordingly, the following description is not to be taken in a limiting sense, and the scope of the invention should be defined by the following claims and their equivalents.

An improved and more efficient method is needed to implement the cooling process for the stave. 1-3, the repair system includes an inflated bladder 20, a concentric internal rigid pipe 1, a custom machined grout inlet 7, a vent tube 8, (3). In a preferred embodiment of the first aspect of the invention, the internal rigid pipe 1 is inserted in a compromised stave pipe 27. The expandable bladder 20 is inserted into the internal rigid pipe 1 as far as the stave 30. The bladder 20 is expanded to a certain pressure and the epoxy 15 is injected into the compostable stiffening inlet / outlet pipe 27 and is introduced into the interior rigid pipe 1 through the grout inlet 7 in the fitting 2, Lt; / RTI > The epoxy 15 is injected until it fills the entire first annular gap 28 between the compartmental stave inlet / outlet pipe 27 and the internal rigid pipe 1. An optional vent tube 10 extending beyond the length of the first annular gap 28 is positioned within the first annular gap 28 to allow the displaced air to exit. After the epoxy 15 is injected, the epoxy cures. At the end of the curing process, the bladder 20 is shrunk and removed. In the preferred embodiments, the internal rigid pipe 1 is an epoxy pipe.

In the second embodiment of the first aspect of the present invention, the external rigid pipe 5 may be positioned around the compartmental stake pipe 27. Grout inlet 7 is formed or attached via external stiffening pipe 5. The flexible seal 6 is fitted to one end of the external rigid pipe 5. The flexible seal (6) has an optional hole (31) which allows the displaced air to be discharged. The epoxy 15 is injected until it fills the entire second annular gap 29 between the compartmental stave inlet / outlet pipe 27 and the external rigid pipe 5. After the epoxy 15 is injected, the epoxy cures. In the preferred embodiments, the external rigid pipe 5 is an epoxy pipe.

In the third embodiment, the compartmentalized stave inlet / outlet pipe 27 is preferentially removed from the stave 30 to provide a hole therethrough. The hole is rethreaded and a new inlet / outlet pipe is installed in the hole. Thereafter, the method steps of the first and second embodiments will follow.

Once the repair process is complete, in a preferred embodiment, the stave inlet hose is again connected to the epoxy pipe 1 through a water circuit and associated connector 4 and elbow 11, .

In some embodiments, a dowel rod 23 and a pull rod 25 are used to assist in inserting and removing the bladder 20.

In a further aspect of the present invention there is provided a repair system kit for a cooling stove used in a blast furnace comprising an inflatable bladder 20, (One); A grout inlet 7; And a vented tube (8). The repair system kit may further comprise an external rigid pipe 5 and a flexible seal 6.

4-6 illustrate representative staves 30 and stave inlet / outlet pipes 27 that can be repaired with the repair system and repair kit of the present invention. In particular, FIG. 4 illustrates a weld or pipe crack 50 caused by a heating and cooling cycle, FIG. 5 illustrates a pipe or weld crack 50 caused by flow disruption, FIG. Illustrate a pipe or weld crack 50 caused by plug washing.

The repair method allows the user to reestablish the water in the composting pipe in contact with the stave without losing the cooling effect of the water.

The epoxy system provides the following advantages over conventional repair methods:

- the cooling effect is improved compared to other methods;

- can be mounted for short outage periods;

- can be fitted if a leak is found;

- use existing cooling circuits;

- the stress applied to the stave is small;

- repair both upper and lower inflows or welded plug welds;

- Provides increased strength to the stave inlet / outlet pipe.

In the foregoing specification, various features are provided for an embodiment of the invention. The method according to the present invention should not be interpreted as including the features claimed in the invention more than the features clearly described in the respective claims. However, as in the claims below, the subject matter of the invention includes fewer features than all the features of one described embodiment. The following claims are therefore incorporated into the Detailed Description of the Invention, and each claim is provided as an individual embodiment.

Although the present invention has been described only in terms of the feature embodiments described in detail herein, it should be understood that these embodiments are merely illustrative of the general principles of the invention and are not necessarily limited to these embodiments. It will be apparent to those skilled in the art, without departing from the scope and spirit of the present invention, that any given materials, process steps or feature variations and modifications in formulas will be apparent to those skilled in the art, and all such modifications and improvements are considered to be within the scope of the following claims do.

Claims (9)

CLAIMS 1. A method for repairing an in situ cooling stave, the cooling stave having a stave inlet / outlet pipe coupled to a cooling pipe in a cooling stave,
The method comprising:
Inserting a pipe into the stave inlet / outlet pipe to form a first annular portion;
- inflating the bladder arranged in the cooling stave and the pipe;
Injecting a first non-cured epoxy material into the first annular portion;
Curing the first non-cured epoxy; And
- removing the bladder. The method according to claim 1,
Wherein the first end of the distal pipe relative to the cooling stave further comprises means for injecting the first non-cured epoxy into the first annular portion, wherein the first end of the pipe in the proximal position relative to the cooling stave wherein the second end of the proximal pipe further comprises means for discharging the displaced air while the first non-cured epoxy is injected into the first annular portion. The method according to claim 1,
The method comprising:
Providing an external pipe external to the stave inlet / outlet pipe to form a second annular portion;
Injecting a second non-cured epoxy material into the second annular portion; And
- allowing the second non-cured epoxy material to cure. ≪ Desc / Clms Page number 13 > The method of claim 3,
Wherein the first and second non-cured epoxies are cured concurrently. The method of claim 3,
Wherein the first non-cured epoxy is cured before the second non-cured epoxy is cured. The method of claim 3,
Further comprising means for injecting a second non-cured epoxy into the second annular portion at a first end of the outer pipe in a distal position relative to the cooling stave, Characterized in that the second end further comprises a boot configured to form a seal with the cooling stave and the outer pipe, said second end having an opening communicating open communication with the second annular portion A method for repairing a cooling stove. A method for repairing an in situ cooling stove,
The method comprising:
- rethreading the holes in the formed cooling staves after removing the compromised stave inlet / outlet pipe;
Mounting a new inlet / outlet pipe;
Inserting an inner pipe into the new stave inlet / outlet pipe to form an annulus;
- inflating the bladder within the cooling stave and the inner pipe;
Injecting a non-cured epoxy material into the annular portion;
Curing the non-cured epoxy; And
- removing the bladder. A repair system kit for a cooling stove used in a furnace,
Wherein the cooling stave has a stave inlet / outlet pipe including an expandable bladder, an internal rigid pipe, a grout inlet, and a vent tube. 9. The method of claim 8,
Characterized in that the cooling system further comprises a concentric outer pipe and a flexible rubber seal.

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