Lime shaft kiln refractory masonry construction method

Lime kiln refractory masonry construction process: familiar with drawings and related materials → erecting scaffolding → laying fiberboard → masonry refractory brick construction → construction acceptance → scaffolding removal → site cleaning

1. Scaffolding

1.1 Selection of scaffolding materials
(1) Fastener-type steel pipe scaffolding is used. The steel pipe is selected from φ48*3.5 welded pipe. The surface of the steel pipe should be free of cracks, smooth and clean, and should not be used for steel pipes with severe corrosion, thin walls and severe bending and fission.
(2) When selecting fasteners, it should be ensured that the joint surface of the fastener and the steel pipe is strictly reshaped, and the fasteners with severe corrosion, deformation, cracks, and damaged bolt threads should not be used.
(3) The scaffolding board is made of 4000mm*300mm*50mm wooden scaffolding board, and the scaffolding board must not have more than the allowable deformation and defects.

1.2 The erection of scaffolding

(1) Horizontal row and column spacing: 1m;
(2) Vertical step distance: 1.5m; vertical steel pipe 6000×Φ48×3.5/piece,
(3) There should be no less than 2 lap joints, and the lap length should not be less than 500.
(4) The wooden springboard should have no loose joints with a diameter greater than 50, and no dead joints greater than 70 in the width direction.

1.3 Windlass erection
In order to prevent the hanging frame from rotating, two steel wire ropes are pulled from the top to the bottom of the lime kiln as slideways, and pass through the steel pipes on both sides of the hanging frame to ensure that the hanging frame can pass through the hanging brick holes smoothly during the rising process of the hanging frame.

2. Construction of refractory materials in the furnace

1) The masonry of the lime kiln kiln lining should be based on the center line of the kiln shell. When the verticality tolerance and diameter deviation of the center line of the kiln shell meet the requirements of the inner shape of the kiln lining, the masonry can be built according to the kiln shell as the guide surface. , and check the thickness of the masonry with the template in time.
2) The mud in all brick joints of the kiln lining body should be full and dense, with uniform thickness, and there should be no brick joints lacking slurry. Inspections should be carried out at any time during the masonry process.
3) The thickness of the brick joints of the kiln lining should be inspected at 10 locations per 5m2 of each part of the masonry with a feeler gauge, and the brick joints with a thickness greater than 50% of the specified brick joint thickness should not exceed 4 locations.
4) When kiln lining is built, the actual deviation between the layer height and the control elevation should be checked frequently so as to be adjusted in time to eliminate the accumulated masonry errors.
5) After the masonry kiln lining body, the brick joints should be horizontal and vertical, uniform and beautiful. The brick joints of adjacent brick layers or the joints of adjacent layers of prefabricated blocks shall be staggered, and no heavy joints shall be allowed. The staggered distance of brick joints should be greater than 12mm; the distance of prefabricated block staggered joints should not be less than 30% of its length. The joints of adjacent refractory fiber mats should be staggered, and the staggered spacing should not be less than 100mm.
6) The brick joints on the heating surface of the kiln lining must be tightly jointed. Pointing should be carried out when the mud is in a semi-dry state after masonry, and the joints of the heating surface of the prefabricated blocks should also be pointed when the mud is too hard.
7) When laying refractory bricks, a wooden hammer or a rubber hammer should be used for alignment instead of an iron hammer. After the mud in the kiln lining dries up, it is strictly forbidden to use the method of beating to correct its quality defects.
8) When refractory bricks need to be processed during the masonry process, they should meet the following requirements: ① Do not cut and chisel bricks directly on the masonry; ② The processed surface of the bricks shall not be used for the heating surface; ③ The width (thickness) of the processed bricks , Bricks with cracks that should not be less than 1/2 (2/3) of the original brick width (thickness) shall not be used.
9) Expansion joints should be left around the thermowell set in the kiln lining, and the joints should be filled with refractory fibers evenly and densely.
10) After the kiln lining is completed, it is strictly forbidden for the masonry to have local subsidence and cracking of brick joints. The inner wall of the kiln lining after masonry must be flat and smooth, and there should be no reverse stagger along the cutting direction, and a forward stagger of no more than 2mm for individual bricks is allowed.
11) The inner surface of the kiln lining should be flush. When checked with a 2m long ruler, the allowable deviation of its straightness is ±5mm. When inspected with an arc-shaped template with a mysterious length of 1m in the circumferential direction, the gap should not exceed 2mm.
12) The verticality tolerance of the masonry on the inner surface of the kiln lining should not exceed 3mm per meter of height, and the verticality tolerance of the full height should not exceed 15mm.
13) The inner wall of the kiln lining should be concentric up and down, and its coaxiality tolerance should not be greater than 15mm.
14) After the kiln lining is built, measure the inner radius of any section in the horizontal direction, and the radius tolerance should not exceed ±12mm.

During the construction process, the construction quality should be checked frequently, and problems should be found and solved at the first time.