CN102183148A - Process for repairing thermal insulating layer in a pipeline of heating furnace - Google Patents

Abstract

The method for repairing the heat insulation layer in the heating furnace pipeline belongs to the maintenance field of metallurgy, furnace industry and thermal pipeline, and is mainly used for the maintenance of the heat insulation layer in the air and gas pipeline of the heating furnace. It includes the following steps: ⅰ, removing the damaged part; ⅱ. Weld and install Y-shaped anchor hooks on the inner wall of the metal pipe; ⅳ. Paste a 30mm thick fiber blanket on the inner wall of the metal pipe for heat insulation and cover it with plastic film; ⅳ. Finally, pour the fiber castable as a whole by manual projection. The invention can be constructed by ordinary laborers, and the construction period is obviously shortened, especially in the pipe elbow and special-shaped parts, the service life after the maintenance of the invention is increased from 3 years to more than 10 years.

Description

Repairing Method of Heat Insulation Layer in Heating Furnace Pipeline

technical field

The invention belongs to the field of metallurgy, furnace industry and maintenance of thermal pipelines, and is mainly used for maintenance of heat insulation layers in heating furnace air and gas pipelines.

Background technique

During the operation of the air and gas pipelines of the heating furnace, the refractory material of the heat insulation layer in the pipeline sometimes falls off, especially at the elbow of the pipeline. The shed refractory material is brought into the pipeline in front of the burner by the flowing air or gas, blocking the burner, resulting in a decrease in the working efficiency of the burner, and in severe cases, the burner is burned, and a major accident occurs that is forced to shut down the furnace.

The traditional method of repairing the heat insulation layer in the pipeline is to build the layer of light heat insulation bricks in the damaged pipeline, completely remove it according to the expansion joints, and then use light heat insulation bricks on the damaged parts according to the original masonry method. Masonry restored.

The traditional construction method has a large amount of construction work, great construction difficulty, long construction time, short service life of the repaired insulation layer, and requires technical requirements such as high-tech bricklayers and complex special-shaped bricks.

Contents of the invention

The invention provides a method for repairing the heat insulation layer in the heating furnace pipeline with short construction time and long service life of the repaired heat insulation layer.

The present invention comprises the following steps:

1. Remove the damaged part;

2. Weld and install Y-shaped anchor hooks on the inner wall of the metal pipe;

3. Paste a 30mm thick fiber blanket on the inner wall of the metal pipe for heat insulation, and cover it with a plastic film;

4. Finally, pour the fiber castable as a whole by artificial projection method.

The Y-shaped anchor hook is made of Φ8 round steel made of Q235, which is welded into a Y shape formed by a vertical steel and two oblique steels, wherein the angle between the vertical steel and the oblique steel is 135 degrees, and the two The included angle between the root oblique steel is 90 degrees, the length of the vertical steel is 40mm, and the length of the two oblique steels is 50mm.

The artificial projection method is projected layer by layer on the work surface. When the projection thickness reaches the design size, compact and smooth it with a trowel, and leave an expansion joint every 1.5-2 meters. The width of the expansion joint is 10 -15mm, the expansion joints are filled with aluminum silicate refractory fiber blanket; the lining layer of the vertical pipeline is constructed in layers from bottom to top, and the thickness of each layer is 700-1000mm. Construction of the second layer; the construction of the heat insulation layer in the horizontal pipeline, and the second layer can be constructed after natural curing for 3-4 hours after the construction of each layer.

The invention can be constructed by ordinary laborers, and the construction period is obviously shortened, especially in the pipe elbow and special-shaped parts, the service life after the maintenance of the invention is increased from 3 years to more than 10 years.

Detailed ways

Example:

1. Make Y-shaped anchor hooks, fiberboards, and fiber castables.

2. The Y-shaped anchor hook is made of Φ8 round steel, the material is Q235, and it is welded into a Y shape. The angle between the vertical steel and the inclined steel is 135 degrees, and the angle between the two inclined steels is 90 degrees. The length of the straight steel is 40mm, and the length of the two oblique steels is 50mm.

3. After the gas test is qualified after the shutdown of the furnace, confirm that the blind valve of the gas pipeline is completely closed, and open the hot air of the heating furnace and the damaged part of the gas pipeline.

4. Remove the refractory material layer on the damaged part of the pipeline and clean it up.

5. The damaged part of the pipeline is installed with setting-out welding and Y-shaped anchor hook.

6. Cut the fiberboard according to the size of the installation position of the Y-shaped anchor hook in the pipeline.

7. Install fiberboard: the fiberboard joint width is required to be ≤0.5mm, and the fiberboard must be firmly bonded with high-temperature cement, and the straightness of the fiberboard is ≤1.5 mm.

8. The surface of the fiberboard is covered with a layer of plastic film to prevent direct contact with the fiber castable.

9. Add the prepared fiber castable to the mixer, add tap water, stir for 2-3 minutes, and the material can be discharged; the stirred fiber castable should be used up within 20 minutes to prevent the material from induration due to too long interval Construction Quality;

10. Use the artificial projection method to mix the fiber castable; project it layer by layer on the working surface. When the projected thickness reaches the designed size, use a trowel to compact and smooth it, and leave an expansion joint every 1.5-2 meters , the width of the expansion joint is 10-15mm, and the expansion joint is filled with aluminum silicate refractory fiber blanket; the inner lining layer of the vertical pipeline is constructed in layers from bottom to top, and the thickness of each layer is 700-1000mm. The second layer can be constructed after curing for 3-4 hours; the heat insulation layer in the horizontal pipeline is constructed, and the second layer can be constructed after natural curing for 3-4 hours after the construction of each layer;

11. Refractory material maintenance for 24 hours

12. Ignition oven: After heating up the oven for 104 hours according to the oven curve for heating furnace construction, it can be put into operation.

The raw material for the fiber castable in this example is refractory fiber needle-punched blanket. The refractory fiber needle-punched blanket is produced by the spinning method and formed by dry needle punching. The fiber diameter is small, the fiber is long, the tensile strength is high, and there is no binder , does not contain any additives. It has low-temperature type LT-J, standard type RT-J, high-temperature type RT, high-purity type HP-J, high-temperature type HT-J, ultra-high temperature type HS-J, the fiber castable has a certain load-bearing capacity, anti-airflow Strong scouring ability, good air tightness, long service life and other advantages.

Claims (3)

1. heating furnace pipeline inner insulating layer restorative procedure is characterized in that comprising the steps:

ⅰ, dismounting damaged location;

ⅱ, on inner wall of metal tube welded and installed Y type anchoring hook;

ⅲ, paste the thick tapetum fibrosum of 30mm in metal pipe internal wall and carry out heat insulationly, and cover with plastic foil;

ⅳ, use artificial projective method that fibre castable is integrated poured at last.

2. heating furnace pipeline inner insulating layer restorative procedure according to claim 1, it is characterized in that described Y shape anchoring hook Φ 8 round steel, material is Q235, be welded into a vertical steel and two Y shapes that oblique steel constituted, wherein vertically the angle between steel and the oblique steel is 135 degree, angle between two oblique steel is 90 degree, and vertically the length of steel is 40mm, and the length of two oblique steel is 50mm.

3. heating furnace pipeline inner insulating layer restorative procedure according to claim 1, it is characterized in that described artificial projective method is incident upon on the scope of operation layer by layer, when projection thickness reaches design size, with trowel compacting, troweling, stay every 1.5-2 rice and to establish an expansion joint, the width at expansion joint is 10-15mm, and the expansion joint adopts alumina-silicate refractory fibre blanket to fill; Vertical pipeline inner liner construction in layer from bottom to top wherein, every layer thickness is 700-1000mm, the second layer of can constructing after natural curing 3-4 hour after every layer of construction; The construction of horizontal pipe inner insulating layer, the second layer of can constructing after natural curing 3-4 hour after every layer of construction.