Construction instructions for furnace wall insulation of circulating fluidized bed boilers

1. Description of construction process

    Before casting the refractory castable, clean the casting part first, and no debris is allowed to adhere. The casting surface of the mold used should be coated with a layer of engine oil. All pre-embedded metal parts and cast metal surfaces should be coated with a layer of asphalt paint with a thickness of 2 mm before pouring. The castable should be used up within 30 minutes after being mixed, and it should be cast to the specified thickness at one time and vibrate tightly. For parts with a thickness greater than 250 mm, layered casting should be used. When pouring the upper layer, the vibrating rod should not touch the lower fabric layer.

1.1 The heat-resistant steel bar grid in the refractory castable, unless otherwise specified, uses φ6 steel bar 120×120 grid, the steel bar joints are tied with φ1.6 galvanized iron wire, and all steel bars and booms are coated with δ2 pitch before pouring. .

1.2 The fillings in the expansion joints are ordinary aluminum silicate refractory fiber felt except where indicated. If the size of the expansion joint is not injected, if the joint is caused by bricklaying, the joint will be compressed to 10mm when filled with δ15 ordinary aluminum silicate refractory fiber felt for bricklaying. At this time, the felt and the refractory bricks are cemented with an acidic high temperature inorganic bonding agent. If this joint is produced by refractory concrete pouring, the filling in the joint is δ20 ordinary aluminum silicate refractory fiber felt, which is allowed to compress freely during pouring.

1.3 There are 6 to 8 expansion joints in the circumferential direction of the drum, with a width of 8 to 10 mm, and an expansion joint with a width of 8 to 10 mm at a longitudinal interval of 2 to 3 m.

1.4 The material quantity and specifications of the curved tile insulation material for pipeline insulation are determined by the construction budget.

1.5 Before pouring refractory concrete with secondary air nozzles and coal nozzles, apply a layer of δ2mm pitch to facilitate expansion.

1.6 The insulation thickness of the primary and secondary air ducts is 100mm, and the outer side is δ20mm plastering layer (not shown in the bricklaying diagram).

1.7 The insulation layer of the boiler downcomer, steam outlet pipe, rising pipe and economizer outlet pipe is covered with a layer of galvanized white iron.

1.8 The thickness of the thermal insulation layer of the superheated steam pipeline is 140 mm, and the outer side is the surface layer.

1.9 Membrane-type water-cooled wall tube-clad furnace wall is insulated with aluminum silicate fiber blanket, and the outer side is the insulation layer of the surface layer with a thickness of 180-200 mm.

1.10 Use aluminum silicate fiber felt with a thickness of 100mm for heat preservation for the ignition oil gun and the air duct, and the thickness of the outer surface of the heat preservation layer is 20mm.

2. Description of furnace wall construction

2.1 Refractory brick and brick seam 1.8～2.2mm, insulation brick and brick sewing machine 5～7mm. The masonry of thermal insulation bricks should be smooth, and the mortar joints should be even. Where the masonry is inconvenient, it should not be filled with broken bricks and should be filled with concrete.

2.2 Expansion joints should be straight and the width deviation +2--0. There shall be no mortar, broken bricks and sundries in the joints, and fire-resistant soft filler with a thickness slightly larger than the gap shall be filled in the joints. When filling aluminum silicate fiber, its surface should be evenly smeared with refractory cement slurry.

2.3 Where the pipe penetrates the wall, the surface of the pipe is bound with a δ10mm thick aluminum silicate fiber felt with φ1.2mm thin iron wire, and then heat-resistant concrete is poured.

2.4 There must be no dirt on the surface of the steel bars and hooks in the heat-resistant concrete. The surface of steel bars and metal parts is coated with an asphalt layer, and the thickness is not less than 2 mm.

2.5 During construction, full consideration should be given to taking measures to ensure the precipitation of moisture during the boiler drying. Furnace walls with external protective plates shall be fully welded after the furnace is completed. Only spot welding is allowed before the furnace. The surface sealing layer of the furnace wall is carried out after the completion of the boiler oven.

2.6 For furnace walls equipped with protective panels on the outside, no gaps should be left between the insulation layer and the protective panels. During the construction, the gap between the guard plate and the outer surface of the furnace wall is filled with aluminum silicate fiber uniformly coated with refractory mortar on the surface.

2.7 The furnace wall shall be fastened firmly, and the rigid beam shall be tamped with perlite cement insulation concrete.

2.8 The furnace wall at the combustion chamber should be flat, and the horizontal, vertical, and thickness errors should not exceed the relevant specified values. The furnace door holes and inspection holes should be constructed with reference to the drawings. The pipes should not be leaked during construction through the wall.

2.9 The upper and lower special-shaped bricks at the brick bracket should leave enough space according to the design to enrich the aluminum silicate refractory fiber. The upper plane of the upper profiled brick and the lower plane of the lower profiled brick should be flush with the plane of the masonry at the same elevation, and the gap between the lower profiled brick and the bracket should be filled with thermal insulation.

2.10 The two draw hook bricks at the masonry draw hook standard bricks should be aligned with each other, their fire facing surface should be on the same plane as the furnace wall where they are located, and the center of the draw hook brick should be 3 mm lower than the center of the draw hook tube. The voids of the drawn bricks should be filled with thermal insulation fillers.

2.11 The mortar used for masonry should be the same material as the masonry, and should not be mixed.

3 Instructions for the construction of the furnace wall of the returner

The return device is a key component of the boiler, and its masonry should be constructed in strict accordance with the drawings.

4 Description of the construction of fluidized bed pouring

During the fluidized bed pouring construction, after the hood is installed in place, the small holes of the hood are covered with a plastic pipe or plastic cloth, and temporarily fixed, and then the refractory concrete is poured. After the refractory concrete dries hard, the plastic tube or plastic cloth for sealing the small holes on the hood must be removed, and the small holes of the hood must be checked one by one to see if they are unblocked. If they are not unblocked, they should be cleaned.

5 Other instructions

5.1 The process of the expansion device of the returner

The upper end of the expansion device of the returner is fixed. The structure is upper and lower sleeve type, the outer layer is made of stainless steel Bowen expansion joints, and the aluminum silicate refractory fiber is filled between the sleeve and the Bowen expansion joints, and the filling direction of the silicate inscription is the vertical direction.

Construction sequence:

The upper steel plate connecting the expansion device and the expansion joint are sleeved together, and the aluminum silicate fiber is filled between the expansion joint and the upper steel plate sleeve.

Put the expansion joints, the upper and lower steel plates in place, and weld them according to the drawings.

Fill the aluminum silicate fiber between the ash guide pipe and the upper steel plate sleeve.

Install the ash guide pipe.

Install the ash pipe.

5.2 The installation process of the expansion and sealing device at the bottom of the separator refers to the returner.

5.3 The junction between the lower part of the furnace and the combustion chamber: this place should be constructed strictly in accordance with the requirements of the drawings, and no steps should appear at the junction with the membrane water wall.

5.4 The "Masonry Instructions" shall be used in conjunction with the bricklaying drawings.

Zibo Yuntai Furnace Technology Co., Ltd. is a professional supplier of a series of services for the production, construction, oven and maintenance of wear-resistant refractory products such as circulating fluidized bed boilers, biomass boilers, pulverized coal boilers, and garbage incinerators. The main products are power plant castables, high-strength wear-resistant castables, corundum refractory plastics, corundum wear-resistant castables, thermal shock resistant castables, low cement castables, high-strength lightweight thermal insulation castables, refractory concrete, aluminum silicate fiber Refractory products such as blankets, aluminum silicate fiberboard, aluminum silicate fiber paper, refractory clay bricks, high alumina bricks, aluminum phosphate wear-resistant bricks, high temperature cement, PA cement, refractory cement and other refractory products, Shandong Yuntai Technology specializes in the production of wear-resistant refractory casting The material has good wear resistance, high quality, long life and complete models. Welcome to inquire!