Method for transforming slag tapping pipe expansion box

Abstract

The invention discloses a slag tapping pipe expansion box transformation method. Under the shutdown cold state of the boiler, an expansion box bottom plate, an annular sealing plate and a wall barrel of the expansion box are machined; after rolling forming, the lower end of the wall cylinder is welded with the expansion box bottom plate; the upper end of the wall cylinder is welded with the annular sealing plate; a sealing sleeve is formed around the slag discharging pipe in a rolling mode; after rolling forming, the upper end of the lower end wall cylinder of the sealing sleeve is welded with the annular sealing plate; a sealing gap between the slag discharge pipe and the sleeve is filled with heat preservation cotton; slag leakage or reentrainment of dust in the conveying process is reduced; the high-temperature-resistant sealing material reduces friction, stable and normal operation of the slag cooler is not affected, and the adopted materials are all conventional materials, low in price, convenient to purchase, process and manufacture, simple, convenient and easy to implement.

Description

Technical Field

[0001] The invention relates to the field of boiler slag discharge, and in particular to a method for transforming an expansion box of a slag discharge pipe. Background Art

[0002] The circulating fluidized bed boiler is a low-pollution, environmentally friendly, clean-burning boiler that uses an in-furnace combustion desulfurization process. Through low-temperature combustion in the circulating fluidized bed, sulfides and nitrogen oxides are effectively removed, thereby greatly reducing the content of pollutants in the flue gas. Due to the energy-saving and environmentally friendly characteristics of the circulating fluidized bed, it has become increasingly popular among users in recent years. With the update of technology, the current development trend of circulating fluidized bed boilers is large-scale. The large-scale development of circulating fluidized beds directly leads to a significant increase in the amount of slag discharged from the boiler.

[0003] Due to the change in the operating conditions of the boiler between the cold and hot states, the slag pipe and the inlet of the slag cooler cannot be fixedly connected. The slag pipe of some boilers is directly inserted into the slag funnel, and requires a large amount of movement, resulting in a large connection gap between the slag outlet of the circulating fluidized bed boiler and the inlet of the slag cooler. When the slag flow rate is large, defects such as slag spraying will occur, the dust pollution at the operation site is heavy, and the splashing of leaked slag is serious.

[0004] There are many structural forms that use feed pipes and expansion joints to offset the thermal expansion of boiler slag pipes. Although this method can offset most of the thermal expansion of the slag pipe and reduce pollution problems such as slag leakage and secondary dust, the use of expansion joints has its fatal weakness, that is, when the expansion and contraction times and high-temperature ash scouring and wear exist at the same time, the service life is generally low. The sealing ring used for the expansion joint of the slag pipe is damaged due to long-term alternation of hot and cold, and the sealing is not tight, so slag leaks out. Summary of the invention

[0005] The purpose of the present invention is to solve the problem of damage to the sealing ring of the expansion joint of the slag lowering pipe by improving the technology of the slag lowering pipe. A method for modifying the expansion box of the slag lowering pipe is proposed.

[0006] A method for modifying a slag pipe expansion box; characterized in that the method steps are as follows:

[0007] 1) When the boiler is shut down and in cold state, a certain vertical gap is formed between the slag lowering pipe and the inlet of the slag cooler;

[0008] 2) The bottom plate of the expansion box is processed according to the inlet pipe diameter of the slag cooler; the bottom plate of the expansion box passes through the gap between the lower slag pipe and the inlet of the slag cooler, and is welded to the inlet of the slag cooler;

[0009] 3) Process the annular sealing plate according to the diameter of the slag lower pipe; its internal opening is sleeved on the slag lower pipe, the annular sealing plate passes through the gap between the slag lower pipe and the inlet of the slag cooler, and is sleeved on the slag lower pipe for temporary positioning;

[0010] 4) Rolling the wall tube of the expansion box around the lower slag pipe; after rolling, the lower end of the wall tube is welded to the bottom plate of the expansion box; the upper end of the wall tube is welded to the annular sealing plate;

[0011] 5) Rolling a sealing sleeve around the lower slag pipe; after rolling, the upper end of the lower end wall of the sealing sleeve is welded to the annular sealing plate;

[0012] 6) The sealing gap between the slag pipe and the casing is filled with thermal insulation cotton;

[0013] 7) When the boiler starts the heat engine and turns from a cold state to a hot state, the radial and axial expansion of the slag lowering pipe is free and unrestricted, and the sealing gap insulation cotton provides a sealing effect. The beneficial effects of the present invention are:

[0014] Compared with the existing technology, after the transformation, the leakage of slag or secondary dust in the transportation process is reduced; the high temperature resistant sealing material reduces friction and does not affect the smooth and normal operation of the slag cooler. The materials used are all conventional materials, which are low in price, easy to purchase and process, and simple and easy. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is the structural diagram of the slag pipe expansion box.

[0016] Figure 2 The process flow for slag pipe transformation is as follows:

[0017] In the figure: 1 slag lower pipe, 2 slag cooler inlet, 3 expansion box, 4 sealing plate, 5 sealing sleeve. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] A boiler slag pipe expansion box comprises a slag pipe, an expansion box and a sealing plate.

[0020] The slag lower pipe is installed below the boiler wall, and the lower part of the slag lower pipe corresponds to the inlet of the slag cooler.

[0021] After the boiler is started and expands due to heat, the lower slag pipe can expand and extend downward.

[0022] An expansion box is welded at the upper end of the slag cooler inlet. The diameter of the expansion box is larger than the diameter of the lower slag pipe and the diameter of the slag cooler inlet. The height of the expansion box is larger than the length of the lower slag pipe expanded by heat.

[0023] The expansion box is used to provide a holding space for the slag lower pipe to expand.

[0024] A sealing plate is welded to the upper end of the expansion box.

[0025] The sealing plate is an annular component with an internal opening that is sleeved on the slag pipe. The inner diameter is slightly larger than the outer diameter of the slag pipe in consideration of the thermal expansion of the slag pipe. The outer diameter needs to completely cover the expansion box, and the outer diameter is larger than the outer diameter of the expansion box.

[0026] A 15 cm high sealing sleeve is welded on the upper surface of the sealing plate, and the gap between the sealing sleeve and the lower slag pipe is 20 mm. The gap between the lower slag pipe and the sealing sleeve is filled with thermal insulation cotton as a seal.

[0027] When slag is discharged, the diameter of the slag discharge pipe increases, the radial clearance decreases and the insulation cotton is compressed, and the clearance between the slag discharge pipe and the casing is used for the radial displacement of the boiler slag discharge pipe;

[0028] The slag pipe is inserted into the sealing plate axially, and expands and contracts freely in the inner hole to achieve the axial displacement of the slag pipe; the high temperature resistant material insulation cotton is used as a seal to reduce the leakage of slag or secondary dust during transportation; the high temperature resistant sealing material of the axial and radial expansion parts reduces the friction, and there is basically no wear between the components. The free expansion space margin is used to ensure that the thermal expansion of the slag pipe does not affect the smooth and normal operation of the slag cooler. The materials used are all conventional materials, which are low in price, easy to purchase and process, and simple and easy to operate.

[0029] In the specific implementation, when modifying the existing slag pipe, the method and steps are as follows:

[0030] 1) When the boiler is shut down and in a cold state, a certain vertical gap is formed between the slag lower pipe and the inlet of the slag cooler, and the gap size is about 6-10CM.

[0031] 2) The bottom plate of the expansion box is processed according to the inlet pipe diameter of the slag cooler. Its internal opening is sleeved on the inlet of the slag cooler, and its inner diameter is equal to the inlet of the slag cooler.

[0032] The bottom plate of the expansion box passes through the gap between the lower slag pipe and the inlet of the slag cooler and is welded to the inlet of the slag cooler.

[0033] 3) According to the diameter of the slag pipe, the annular sealing plate is processed. Its internal opening is sleeved on the slag pipe. The inner diameter is slightly larger than the outer diameter of the slag pipe, taking into account the thermal expansion of the slag pipe. The inner diameter is slightly larger than the outer diameter of the slag pipe by 5CM.

[0034] Its outer diameter is equal to the outer diameter of the bottom plate of the expansion box.

[0035] The annular sealing plate passes through the gap between the slag lower pipe and the inlet of the slag cooler, and is sleeved on the slag lower pipe for temporary positioning.

[0036] 4) Use strip plates to roll around the lower slag pipe to form the wall tube of the expansion box. After rolling, weld the side seam joints of the wall tube to form a cylindrical structure.

[0037] The lower end of the wall tube is welded to the bottom plate of the expansion box.

[0038] The upper end of the wall tube is welded to the annular sealing plate. The bottom plate, the wall tube and the annular sealing plate form an expansion box.

[0039] 5) Use strip plates to roll and form a sealing sleeve around the slag lower pipe. After rolling and forming, weld the side seam joints of the sealing sleeve to form a cylindrical structure.

[0040] The upper end of the wall tube at the lower end of the sealing sleeve is welded to the annular sealing plate.

[0041] A sealing gap is formed between the annular sealing plate, the sealing sleeve and the lower slag pipe.

[0042] 6) The sealing gap between the lower slag pipe and the casing is filled with thermal insulation cotton. The thermal insulation cotton can be made into strips, which are wrapped around the lower slag pipe for multiple circles and then squeezed downward into the sealing gap to form a seal.

[0043] 7) When the boiler starts the hot engine and switches from a cold state to a hot state, the radial and axial expansion of the slag lowering pipe is free and unrestricted, and the sealing gap insulation cotton provides sealing.

[0044] Finally, it should be noted that the above description is only an explanation of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail, those skilled in the art can still modify the technical solutions described above or replace some of the technical features with equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for modifying a slag pipe expansion box; characterized in that: The steps are as follows: 1) When the boiler is shut down and in cold state, a certain vertical gap is formed between the slag lowering pipe and the inlet of the slag cooler; 2) The bottom plate of the expansion box is processed according to the inlet pipe diameter of the slag cooler; the bottom plate of the expansion box passes through the gap between the lower slag pipe and the inlet of the slag cooler, and is welded to the inlet of the slag cooler; 3) Processing the annular sealing plate according to the diameter of the slag lowering pipe; Its internal opening is sleeved on the slag lower pipe, and the annular sealing plate passes through the gap between the slag lower pipe and the inlet of the slag cooler, and is sleeved on the slag lower pipe for temporary positioning; 4) Rolling the wall tube of the expansion box around the lower slag pipe; after rolling, the lower end of the wall tube is welded to the bottom plate of the expansion box; the upper end of the wall tube is welded to the annular sealing plate; 5) Rolling a sealing sleeve around the lower slag pipe; after rolling, the upper end of the lower end wall of the sealing sleeve is welded to the annular sealing plate; 6) The sealing gap between the slag pipe and the casing is filled with thermal insulation cotton; 7) When the boiler starts the hot engine and switches from a cold state to a hot state, the radial and axial expansion of the slag lowering pipe is free and unrestricted, and the sealing gap insulation cotton provides sealing.

2. A method for modifying a slag lower pipe expansion box according to claim 1, characterized in that: In step 2), the internal opening of the bottom plate of the expansion box is sleeved on the inlet of the slag cooler, and the inner diameter is equal to the inlet of the slag cooler.

3. A method for modifying a slag pipe expansion box according to claim 1, characterized in that: In step 3), the inner opening of the annular sealing plate is sleeved on the lower slag pipe, and the inner diameter of the annular sealing plate is slightly larger than the outer diameter of the lower slag pipe. Its outer diameter is equal to the outer diameter of the bottom plate of the expansion box.

4. A method for modifying a slag pipe expansion box according to claim 3, characterized in that: The inner diameter of the annular sealing plate is slightly larger than the outer diameter of the slag lower pipe by 5CM.

5. A method for modifying a slag pipe expansion box according to claim 1, characterized in that: In step 4), after rolling and forming, the side seam joints of the wall tube are welded to form a cylindrical structure.

6. A method for modifying a slag pipe expansion box according to claim 1, characterized in that: In step 5), the side seam joints of the sealing sleeve are welded to form a cylindrical structure.

7. A method for modifying a slag lower pipe expansion box according to claim 1, characterized in that: In step 4), an expansion box is formed by a bottom plate, a wall tube, and an annular sealing plate.

8. The method for modifying the expansion box of a slag lower pipe according to claim 1, characterized in that: In step 5), a sealing gap is formed between the annular sealing plate, the sealing sleeve and the lower slag pipe.

9. A method for modifying a slag lower pipe expansion box according to claim 8, characterized in that: The heat-insulating cotton can be made into strips, wrapped around the lower slag pipe for several circles, and then squeezed downward into the sealing gap to form a seal.

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