01 Preparation work before construction
(1) You must be familiar with the various construction requirements of the design drawings. The inlet and outlet ends of the cement kiln (i.e. the inlet and outlet) are castable, and other parts are built with refractory bricks of different materials and brick types.
(2) Before masonry, the interior of the cement kiln should be inspected and cleaned. The masonry part should be inspected and confirmed to see if the protruding height of the internal weld is qualified (generally around 1.5mm). If it is unqualified, it should be polished.
(3) When refractory materials enter the construction site, they should be strictly checked for quantity, quality, etc. before entering the site. Bricks with damaged or different specifications shall not be allowed to enter the site for use.
02 Construction period of cement kiln
Generally, it is a two-shift work system, and the construction and cleaning work shall be completed within the planned number of days.
03 Requirements for refractory brick masonry
Cement kilns can be constructed using dry or wet masonry schemes.
(1) Draw (mark) masonry auxiliary lines: Draw at least 8 auxiliary lines parallel to the longitudinal center line of the kiln body, and draw a masonry auxiliary line perpendicular to it every 4 meters to control the quality of masonry construction.
(2) The first row of each construction section of the kiln body Refractory firebricks are laid from the lower half of the kiln body according to the parallel longitudinal auxiliary lines marked on the kiln shell and with the kiln shell as the guide surface. With the first row of bricks as the reference, the lower half of the cylinder is laid along the longitudinal direction to 2~3 meters, and a bricklaying machine is introduced to continue laying. Then the circumferential refractory firebricks are laid and locked. When each ring of bricks is lined with the last 6~7 refractory bricks, the locked bricks are pre-laid and dry-laid. The last 2~3 rows are locked outside the lock, and the 2~3 rows on both sides of the lock should be laid simultaneously. The locked bricks should be wedged in from the side. When the last brick cannot be wedged in from the side, the inserted bricks are wedged in from the top to level it, and the bottom and sides are densely filled with refractory mortar. Finally, the steel plates should be wedged into the joints of the surrounding bricks to make them firm. When laying bricks, a rubber hammer or a padding wooden board can be used for alignment to avoid damage to the refractory bricks.
(3) Cement kilns should be staggered. The brick joints should be reserved according to the longitudinal auxiliary lines and parallel to the axis of the kiln body. The permissible distortion deviation should not exceed 3mm. Within the full length of the same masonry section, the permissible deviation of ten meters should not exceed 20mm.
04 Construction of cement kiln inlet and outlet castings
(1) Clean the inlet and outlet of the kiln and the construction surface of the cylinder;
(2) Carry out welding of anchors in sections;
(3) Before pouring, remove debris, rust stains, etc. on the anchors, and then apply a certain thickness of asphalt paint. As expansion joints.
(4) Mark out construction sections of 600~1200mm each and carry out section construction;
(5) Support the formwork. If steel plates are used, the thickness must be more than 3.2mm, and if wooden boards are used, the thickness must be 20mm. Before construction, check and confirm the quality of the formwork support to ensure stability and firmness. A layer of oil should be applied to the formwork.
(6) The casting should be compacted and vibrated while pouring.
(7) After the construction of the casting is completed, the formwork should be maintained for at least 48 hours before it can be removed.
