Furnace lining structure for gunning repair of lime shaft kiln and repair process

Abstract

The invention discloses a furnace lining structure for gunning repair of a lime shaft kiln and a repair process, and relates to the technical field of furnace lining repair. The device comprises a first anchoring part, a second anchoring part, expansion bolts, a first anchoring net and a second anchoring net, the expansion bolts are fixed to a refractory brick layer, the first anchoring part and the second anchoring part are fixed to the expansion bolts, the first anchoring net is tightly attached to the refractory brick layer, and the second anchoring net is arranged on the inner side of the first anchoring net. The spraying layer is poured between the first anchoring net and the second anchoring net, the double-layer staggered anchoring nets are arranged on the working layer face in the kiln, the anchoring parts are arranged at the staggered positions, transverse and longitudinal stretching limiting is carried out, and the compactness, strength and abrasion resistance of the lining material can be effectively improved in cooperation with the wet spraying process; therefore, the lining of the lime shaft kiln can be quickly repaired, and the service life of the lining is prolonged.

Description

Technical Field

[0001] The invention relates to a furnace lining structure and a repairing process for lime shaft kiln gunning repair, and relates to the technical field of furnace lining repair. Background Art

[0002] In the production process of the lime shaft kiln, after long-term use, the kiln lining bricks will be severely worn and eroded, the refractory materials in the combustion zone and the preheating zone working layer will be burned and fall off, and a large area of ​​bricks will fall off above the flue bottom plate, that is, the straight section of the kiln mouth, causing the upper kiln ring to tilt and the material distribution in the kiln to be uneven. It is necessary to adjust the coal-stone ratio to improve product quality, resulting in increased energy consumption, which is not conducive to energy-saving production and also poses a safety hazard.

[0003] In order to repair the lime shaft kiln that has been put into production, the existing technology usually adopts a semi-dry spraying method, in which dry powder spray material is transported to the spray gun nozzle through a pipeline using high-pressure gas, water is added at the spray gun nozzle for premixing, and then the paint is sprayed on the lining to repair the lime kiln lining. However, the amount of water added in this method is difficult to meet the precise requirements, and the dry powder spray material material is premixed with water for a short and uneven time before being sprayed onto the wall, resulting in a large amount of dust and a high rebound rate of aggregates, resulting in poor density, strength and wear resistance of the sprayed surface, affecting the service life of the furnace lining. Therefore, a lining structure and repair process for lime shaft kiln spraying repair are proposed to solve the problems existing in the existing technology. Summary of the invention

[0004] The purpose of the present invention is to provide a lining structure for lime shaft kiln gunning repair in view of the defects or shortcomings in the prior art. A double-layer staggered anchoring mesh is arranged on the working surface of the kiln, and anchors are arranged at staggered positions to perform transverse and longitudinal stretching limiting. In combination with a wet spraying process, the tightness, strength and wear resistance of the lining material can be effectively improved, thereby achieving rapid repair of the lime shaft kiln lining and extending the working life of the lining.

[0005] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme: it includes a first anchor 1, a second anchor 2, an expansion bolt 8, a first anchoring net, and a second anchoring net. Several expansion bolts 8 are fixed on the refractory brick layer 9, the first anchor 1 and the second anchor 2 are both fixed on the expansion bolts 8, the first anchoring net is close to the refractory brick layer 9, the second anchoring net is arranged on the inner side of the first anchoring net, and a spray coating 10 is poured between the first anchoring net and the second anchoring net.

[0006] Furthermore, the first anchoring mesh includes first longitudinal steel bars 3 and first transverse steel bars 5, and a plurality of first longitudinal steel bars 3 and first transverse steel bars 5 are cross-welded to form the first anchoring mesh.

[0007] Furthermore, the second anchoring mesh comprises second longitudinal steel bars 4 and second transverse steel bars 6. A plurality of second longitudinal steel bars 4 and second transverse steel bars 6 are cross-welded to form the second anchoring mesh, and the cross-welding points between the second anchoring mesh and the first anchoring mesh are staggered.

[0008] Furthermore, the first anchor 1 and the second anchor 2 have the same structure.

[0009] Furthermore, the first anchor 1 includes an anchor body 11, a front limit plate 12, a rear limit plate 13, and a fixing plate 14. The front limit plate 12 and the rear limit plate 13 are obliquely arranged at the top of the anchor body 11, and the fixing plate 14 is arranged at the bottom of the anchor body 11.

[0010] Furthermore, the fixing plate 14 is provided with a fixing hole 15 .

[0011] Furthermore, the angle between the front limiting plate 12 and the rear limiting plate 13 is 60 degrees.

[0012] Furthermore, the first anchor 1 is arranged transversely with a first longitudinal reinforcement 3, the first anchor 1 is arranged longitudinally with a first transverse reinforcement 5, and the second anchor 2 is arranged in the same manner as the first anchor 1, but the second anchor 2 is arranged starting from the interval of the first anchor 1, thereby forming a staggered grid structure.

[0013] Furthermore, the anchor body 11 of the first anchor 1 is arranged below the first transverse reinforcement 5 and the second transverse reinforcement 6, and the end of the anchor body 11 of the second anchor 2 is located above the first transverse reinforcement 5, and the front end passes through from below the second transverse reinforcement 6.

[0014] Furthermore, the anchor body 11, the front limiting plate 12, and the rear limiting plate 13 are coated with an asphalt coating.

[0015] After adopting the above technical scheme, the beneficial effects of the present invention are as follows: by adopting a double-layer staggered anchoring mesh to be set on the working surface of the kiln, and arranging anchors at the staggered positions, transverse and longitudinal stretching limiting is performed, and the wet spraying process is combined with the tightness, strength and wear resistance of the lining material to effectively improve, thereby achieving rapid repair of the lining of the lime shaft kiln and extending the working life of the lining. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0017] Figure 1 It is a schematic diagram of the structure of the present invention;

[0018] Figure 2 yes Figure 1 A top view of

[0019] Figure 3 yes Figure 2 AA section view;

[0020] Figure 4 yes Figure 3 The enlarged structural diagram at B in the middle;

[0021] Figure 5 yes Figure 3 The enlarged structural diagram at C in the middle;

[0022] Figure 6 is a schematic structural diagram of the first anchor 1 in the present invention;

[0023] Figure 7 yes Figure 6 A second angle view of

[0024] Figure 8 yes Figure 6 A third angle view of

[0025] Fig. 9 It is a schematic diagram of the construction effect of the present invention in a lime shaft kiln.

[0026] Explanation of the accompanying drawings: first anchor 1, second anchor 2, first longitudinal reinforcement 3, second longitudinal reinforcement 4, first transverse reinforcement 5, second transverse reinforcement 6, bolt 7, expansion bolt 8, refractory brick layer 9, spray coating 10, fixture body 11, front limit plate 12, rear limit plate 13, fixing plate 14, fixing hole 15. DETAILED DESCRIPTION

[0027] See also Figure 1-Figure 9 As shown, the technical solution adopted in this specific implementation method is: a lining structure for lime shaft kiln gunning repair, which includes a first anchor 1, a second anchor 2, an expansion bolt 8, a first anchoring net, and a second anchoring net. A plurality of expansion bolts 8 are fixed on a refractory brick layer 9, the first anchor 1 and the second anchor 2 are both fixed on the expansion bolt 8, the first anchoring net is close to the refractory brick layer 9, the second anchoring net is arranged on the inner side of the first anchoring net, and a spraying layer 10 is poured between the first anchoring net and the second anchoring net. The lining of a traditional lime shaft kiln will fall off after a long period of operation, which not only affects the product quality, increases energy consumption, but also poses a safety hazard. Therefore, in this embodiment, anchors and anchoring nets are used as the main frame of the lining, with a length of 200m 3Taking the energy-saving lime shaft kiln as an example, the specific operation is to drive the expansion bolts into the refractory brick layer. The expansion bolts are arranged in a grid form. The size of the expansion bolts is: ￠10*120, with a spacing of 250mm*250mm. The anchors are then fixed to the expansion bolts with bolts. At the same time, steel bars are used for welding, and full welding must be ensured. After the anchor welding is completed, the anchor net is installed. The first anchor net is welded to the anchor close to the refractory brick layer. The second anchor net is welded to the front end of the anchor at an interval from the first anchor net. The two layers of anchor nets cooperate with the anchors to form a three-dimensional protective structure, which can better form an inner lining layer.

[0028] To be more specific, the first anchoring mesh includes a first longitudinal steel bar 3 and a first transverse steel bar 5, and a plurality of first longitudinal steel bars 3 and a first transverse steel bar 5 are cross-welded to form the first anchoring mesh; the second anchoring mesh includes a second longitudinal steel bar 4 and a second transverse steel bar 6, and a plurality of second longitudinal steel bars 4 and a second transverse steel bar 6 are cross-welded to form the second anchoring mesh, and the cross-welding points of the second anchoring mesh and the first anchoring mesh are staggered. In this embodiment, the two anchoring meshes are staggered to obtain a better tensile resistance effect, and the overall firmness and tightness are better after the inner lining layer is formed by spray casting.

[0029] To be more specific, the first anchor 1 and the second anchor 2 have the same structure. The first anchor 1 includes an anchor body 11, a front limit plate 12, a rear limit plate 13, and a fixed plate 14. The front limit plate 12 and the rear limit plate 13 are obliquely arranged at the top of the anchor body 11, and the fixed plate 14 is arranged at the bottom of the anchor body 11. The angle between the front limit plate 12 and the rear limit plate 13 is 60 degrees. In this embodiment, inclined front and rear limit plates are arranged on the top of the anchor, which can form a limiting structure after being welded with the anchor mesh. After the spray coating is cast, it will form a limiting effect on the spray coating, which can more effectively prevent the occurrence of collapse.

[0030] More specifically, the fixing plate 14 is provided with fixing holes 15 for installing bolts, and nuts are used to tighten the fixing plate, so that it is more secure when welding with steel bars.

[0031] To be more specific, the first anchor 1 is arranged with a first longitudinal steel bar 3 at a transverse interval, the first anchor 1 is arranged with a first transverse steel bar 5 at a longitudinal interval, the second anchor 2 is arranged in the same manner as the first anchor 1, but the second anchor 2 is arranged starting from the interval of the first anchor 1, thereby forming a staggered grid structure, the anchor body 11 of the first anchor 1 is arranged below the first transverse steel bar 5 and the second transverse steel bar 6, the end of the anchor body 11 of the second anchor 2 is located above the first transverse steel bar 5, and the front end passes through from under the second transverse steel bar 6. In this embodiment, the first and second anchors are staggered, and the second anchor also passes between the two transverse steel bars, which can support the transverse steel bars of this row from two directions, can provide better supporting effect after welding, and the overall structure is more solid.

[0032] To be more specific, the anchor body 11, the front limit plate 12, and the rear limit plate 13 are coated with an asphalt coating. The anchor is a very important metal component connecting the spray coating and the furnace body itself in the spray construction. In order to effectively control the expansion coefficient between the spray coating and the metal, and avoid cracks in the spray coating and material falling off the spray surface, a layer of asphalt is applied to the end of the anchor after construction, thereby effectively protecting the anchor, and also effectively protecting the spray coating, thereby extending the overall working life.

[0033] In this embodiment, a lining repair process for lime shaft kiln gunning repair is also provided, which adopts a wet spraying process and includes the following process steps:

[0034] Step 1, material selection; HL-65G wear-resistant spray coating is selected and mixed with water in a mixer. Since the surface of the spray coating in the furnace lining is not only impacted and rubbed by limestone, but also blasted by the kiln bottom, scour by hot flue gas and contact with open flames, the spray coating is required to have a high temperature resistance of more than 1200°C, and has high compressive strength, high flexural strength, and a material with small thermal conductivity and linear change rate. Therefore, HL-65G wear-resistant spray coating is selected in this embodiment, which can form an effective wear-resistant lining layer after pouring;

[0035] Step 2, steel selection; due to the different temperatures in the furnace lining, the thermal expansion coefficients of various parts are inconsistent, and when large thermal stress is generated, it is easy to cause the weld to crack, causing the anchor and the gunning material to fall off together. In this embodiment, 0Cr25Ni20 heat-resistant stainless steel bars are selected as the anchor material, which has a high percentage of chromium and nickel, so that it has multiple creep strength and can continue to work at high temperatures. It not only has oxidation resistance and corrosion resistance, but also has good high temperature resistance and carburization resistance.

[0036] Step 3, cleaning the kiln; clean the eroded parts of the inner wall of the lime kiln, and remove the nodules, slag, attachments, etc. in the entire furnace lining, and remove the loose refractory bricks. If there are many nodules in the kiln, you can use high-pressure water mist to spray on the nodule parts at about 300°C on the kiln wall. Spray continuously for 5 minutes at each place, and then let it pulverize naturally. If the pulverization is not completely removed, repeatedly spray with high-pressure water mist until the pulverization is clean. After the water-spraying and nodule removal operation, all the nodules on the kiln wall have fallen off. This not only has no effect on the life of the kiln wall, but also can reduce the workload of subsequent manual nodule removal and speed up the project progress. This is an important process. Whether the kiln wall is clean before spraying is directly related to the service life of the spray material;

[0037] Step 4, anchors and anchor nets are arranged; expansion bolts are driven into the working layer surface (refractory brick layer) in the kiln, and anchors are installed. The expansion bolt size is: ￠10*120, spacing 250mm*250mm. After the expansion bolts are embedded, the anchors are locked on the nuts and then fully welded with stainless steel welding rods. The installation of anchors needs to be determined according to the erosion situation. If the kiln lining peels off to the kiln shell, the anchor nails are directly welded to the kiln shell. If the erosion is not serious, they are normally installed on the refractory brick layer. After the anchors are arranged, the anchor nets are welded. The first layer of anchor nets is welded to the refractory brick layer and the anchors, and the second layer of anchor nets is welded to the ends of the anchors. The double-layer anchor nets not only protect the installation surface, but also better form a three-dimensional frame for subsequent operations.

[0038] Step 5, anchor coating; anchors are very important in spraying construction, connecting the spray coating and the metal components of the furnace body. In order to effectively control the expansion coefficient between the spray coating and the metal and avoid cracks in the spray coating and material shedding on the spray surface, a layer of asphalt is applied to the end of the anchor after construction to form an asphalt layer to protect the anchor;

[0039] Step 6, kiln cleaning: After the mesh is hung, the kiln is cleaned by using high-pressure gas to clean the kiln wall to ensure that there are no impurities on the kiln wall;

[0040] Step 7, hang the center line; in order to ensure that the entire kiln body meets the design requirements of the original drawing after spraying, find the center point from the kiln surface to the kiln bottom, hang the vertical center line, and install multiple probes according to the radius of each belt in the kiln on the drawing to determine whether the spraying thickness meets the kiln radius requirements;

[0041] Step 8, test spraying; In order to achieve the ideal spraying effect, test spraying is required before the formal spraying operation to determine the optimal amount of water, spraying pressure and jet speed. Due to the use of wet spraying, the rebound amount is required to be controlled within 8%. After the test spraying, natural drying is mainly used, and the sound of hitting the sprayed surface with a hammer is used to judge the strength;

[0042] Step 9, anchor inspection: check whether the anchors and anchor meshes at each part are fully welded and whether the welding is reliable; whether the layout spacing and row spacing of the anchors are controlled at about 250mm, so as to prevent the anchors from falling off and causing cracking or falling off of the sprayed surface;

[0043] Step 10, spraying; the spray material after stirring evenly is transported to the spray pipe through a hose through a pressure pump equipped with the spray machine. The spray pipe is equipped with a water pipe, which can pass through a liquid coagulant. The wet-mixed spray material and the coagulant are mixed in the spray pipe, and then sprayed out from the nozzle to enter the formal spraying stage. When the spraying construction begins, the material is continuously pumped and the construction is uninterrupted to avoid flashing and flowing of the material on the spraying surface. The spray gun should be vertically tilted downward to the sprayed surface, and keep a reasonable distance from the sprayed surface. First, start with the deepest concave part of the furnace lining erosion, and then carry out the overall moving spraying from top to bottom in a spiral manner. Lining construction, material construction speed is controlled at 13-15t / h. When spraying, use an adjustable screw to check whether the radius of the kiln and the spray thickness meet the design requirements. If not, spray from bottom to top to meet the design thickness requirements at one time to ensure that there is no interlayer in the sprayed part. The spray material is poured on the anchor net and anchor to form a spray layer. Due to the high pressure of the wet spraying equipment, the spray surface attached to the furnace lining after spraying has a higher density. Therefore, the wet spraying process is combined with pouring and spraying, which effectively improves the tightness, strength and wear resistance of the lining material;

[0044] Step 11, ignite the kiln; gradually remove the moisture from the spray paint inside the kiln lining by slow heating, so as to avoid damage to the refractory materials in the kiln such as cracks and falling off caused by the rapid increase in temperature and the rapid discharge of moisture during the kiln opening process. For specific kiln temperature control, please refer to the kiln temperature control table. Through segmented heating, the final repair of the lining can be effectively completed.

[0045] Kiln temperature control table

[0046]

[0047] The traditional masonry repair process combined with dry spraying is not only time-consuming, usually more than 15 days, but also involves material waste, resulting in a large amount of material consumption and poor results. In this embodiment, the main frame of the lining layer is built by anchors and anchor nets, and then a wet spray repair process is used. This can effectively shorten the maintenance time of the kiln and reduce the losses caused by the shutdown, while also improving the kiln wall effect, truly embodying the four major advantages of saving time, labor, materials, and safety.

[0048] The above description is only used to illustrate the technical solution of the present invention rather than to limit it. Other modifications or equivalent substitutions made to the technical solution of the present invention by ordinary technicians in this field should be included in the scope of the claims of the present invention as long as they do not depart from the spirit and scope of the technical solution of the present invention.

Claims

1. A lining structure for lime shaft kiln gunning repair, characterized in that: The invention comprises a first anchoring piece (1), a second anchoring piece (2), an expansion bolt (8), a first anchoring net and a second anchoring net. A plurality of expansion bolts (8) are fixed on a refractory brick layer (9). The first anchoring piece (1) and the second anchoring piece (2) are both fixed on the expansion bolts (8). The first anchoring net is closely attached to the refractory brick layer (9). The second anchoring net is arranged inside the first anchoring net. A spraying layer (10) is poured between the first anchoring net and the second anchoring net.

2. A lining structure for lime shaft kiln gunning repair according to claim 1, characterized in that: The first anchoring net comprises a first longitudinal steel bar (3) and a first transverse steel bar (5), and a plurality of the first longitudinal steel bars (3) and the first transverse steel bars (5) are cross-welded to form the first anchoring net. The second anchoring net comprises a second longitudinal steel bar (4) and a second transverse steel bar (6), and a plurality of the second longitudinal steel bars (4) and the second transverse steel bars (6) are cross-welded to form the second anchoring net, and the cross-welding points of the second anchoring net and the first anchoring net are staggered.

3. The lining structure for lime shaft kiln gunning repair according to claim 1, characterized in that: The first anchor (1) and the second anchor (2) have the same structure.

4. The lining structure for lime shaft kiln gunning repair according to claim 1, characterized in that: The first anchor (1) comprises an anchor body (11), a front limit plate (12), a rear limit plate (13), and a fixing plate (14); the front limit plate (12) and the rear limit plate (13) are obliquely arranged at the top of the anchor body (11), and the fixing plate (14) is arranged at the bottom of the anchor body (11).

5. The lining structure for lime shaft kiln gunning repair according to claim 5, characterized in that: The fixing plate (14) is provided with a fixing hole (15).

6. A lining structure for lime shaft kiln gunning repair according to claim 5, characterized in that: The angle between the front limiting plate (12) and the rear limiting plate (13) is (60) degrees.

7. The lining structure for lime shaft kiln gunning repair according to claim 1, characterized in that: The first anchors (1) are arranged transversely with a first longitudinal reinforcement (3), the first anchors (1) are arranged longitudinally with a first transverse reinforcement (5), and the second anchors (2) are arranged in the same manner as the first anchors (1), but the second anchors (2) are arranged starting from the spacing of the first anchors (1), thereby forming a staggered grid structure.

8. The lining structure for lime shaft kiln gunning repair according to claim 1, characterized in that: The anchor body (11) of the first anchor (1) is arranged below the first transverse reinforcement (5) and the second transverse reinforcement (6); the end of the anchor body (11) of the second anchor (2) is located above the first transverse reinforcement (5), and the front end passes through the bottom of the second transverse reinforcement (6).

9. The lining structure for lime shaft kiln gunning repair according to claim 5, characterized in that: The anchor body (11), the front limit plate (12) and the rear limit plate (13) are coated with an asphalt coating.

10. A lining repair process for lime shaft kiln gunning repair, characterized in that: The wet spraying process is adopted, which includes the following process steps: Step 1, material selection: select HL-65G wear-resistant spray paint and mix it with water in a mixer; Step 2, steel selection; 0Cr25Ni20 heat-resistant stainless steel bars are selected as anchor material, which has a high percentage of chromium and nickel, giving it multiple creep strengths and continuous operation at high temperatures. It not only has oxidation resistance and corrosion resistance, but also has good high temperature resistance and carburization resistance. Step 3, kiln cleaning: clean the eroded parts of the inner wall of the lime kiln, and remove the nodules, slag, attachments, etc. in the entire furnace lining, and remove the loose refractory bricks. If there are many nodules in the kiln, spray the nodules with high-pressure water mist at about 300°C on the kiln wall. Spray each part continuously for 5 minutes, and then let it pulverize naturally. If the pulverization is not completely removed, spray it with high-pressure water mist repeatedly until it is completely pulverized. Step 4, anchor and anchor net arrangement; drive expansion bolts on the working layer surface (refractory brick layer) in the kiln, and install anchors. The expansion bolt size is: ￠10*120, spacing 250mm*250mm. After the expansion bolts are embedded, the anchors are locked on the nuts and then fully welded with stainless steel welding rods. The installation of anchors needs to be determined according to the erosion situation. If the kiln lining peels off to the kiln shell, the anchor nails are directly welded on the kiln shell. If the erosion is not serious, they are normally installed on the refractory brick layer. After the anchors are arranged, the anchor net is welded. The first layer of anchor net is welded to the refractory brick layer and the anchor, and the second layer of anchor net is welded to the end of the anchor; Step 5, anchor coating: after construction, apply a layer of asphalt to the end of the anchor to form an asphalt layer to protect the anchor; Step 6, kiln cleaning: After the mesh is hung, the kiln is cleaned by using high-pressure gas to clean the kiln wall to ensure that there are no impurities on the kiln wall; Step 7, hang the center line; in order to ensure that the entire kiln body meets the design requirements of the original drawing after spraying, find the center point from the kiln surface to the kiln bottom, hang the vertical center line, and install multiple probes according to the radius of each belt in the kiln on the drawing to determine whether the spraying thickness meets the kiln radius requirements; Step 8, test spraying; In order to achieve the ideal spraying effect, test spraying is required before the formal spraying operation to determine the optimal amount of water, spraying pressure and jet speed, and the rebound amount is controlled within 8%. After the test spraying, natural drying is mainly used, and the sound of hitting the sprayed surface with a hammer is used to judge the strength; Step 9, anchor inspection: check whether the anchors and anchor meshes at each part are fully welded and whether the welding is reliable; whether the layout spacing and row spacing of the anchors are controlled at about 250mm; Step 10, spraying; the spray material after stirring evenly is transported to the spray pipe through a hose by a pressure pump equipped with a spraying machine. The spray pipe is equipped with a water pipe, which can pass through a liquid coagulant. The wet-mixed spray material and the coagulant are mixed in the spray pipe, and then sprayed out from the nozzle to enter the formal spraying stage. When the spraying construction begins, the material is continuously pumped and the construction is uninterrupted to avoid flashing and flowing of the material on the spraying surface. The spray gun should be vertically tilted downward to the sprayed surface and keep a reasonable distance from the sprayed surface. First, the deepest concave part of the furnace lining should be started, and then the overall spiral spraying lining construction should be carried out from top to bottom. The material construction speed is controlled at 13-15t / h. When spraying, an adjustable screw should be used to check whether the radius of the kiln and the spraying thickness meet the design requirements. If the requirements are not met, spray from bottom to top to meet the design thickness requirements at one time to ensure that there is no interlayer in the spraying part. The spray material is poured on the anchor net and the anchor by spraying to form a spray layer; Step 11, ignite the kiln; gradually remove the moisture of the spray paint inside the kiln lining by slowly heating.

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