The large crown is a key part of the glass melting furnace. Therefore, the construction of
refractory bricks in this part is particularly important. It must be treated with caution during construction. The construction plan should be formulated in advance, and tools such as arc pallets and aluminum alloy rulers should be prepared. Before masonry, check the support structure to confirm that the supporting structure is stable and firm. The large dome should be able to withstand the load of the bricks and the construction personnel when the dome is generated; the arc surface of the dome should be consistent and the arc top should be level. , And the radian and arch height of the wooden mold should meet the requirements of the drawings, and the steel structure can be inspected before it can be built. At the same time, pay attention to fire prevention. 2mm thick plywood is laid on the surface of the tire to prevent leakage and facilitate the laying-out.
Refractory bricks must be placed on both sides at the same time when the refractory bricks are placed on the large dome, and they must be placed symmetrically to prevent the dome from being unevenly stressed and inclined; and the stacking height shall not exceed 3 layers. Before laying the bricks, it is required to pre-arrange and measure the actual size of the mud joints at the two ends and the middle of each section; then calculate each ring of mud joints according to the actual size of each section, and each ring shall be divided into 5 sections. The section marks are convenient for inspection to ensure that the final lock bricks are put in properly; the expansion joints between each section are nailed to the dome with long wooden strips for control; when laying. The slope of the stiletto brick should be flat and the angle should be correct. The method of thickening the crevice of the stilt brick should not be used to level the stilt brick. The stilted beam should be filled with thin steel plate; the structure of the stilt should be staggered and thick, and the mud should be full and vertical. The joints should be pulled through for masonry, and the radian of the brick surface should be checked at any time with a radian board, and the flatness of the brick surface should be checked with a long ruler; the splint structure should be symmetrically built from both sides of the splint foot to the center at the same time, and the small head of the splint brick must be indispensable For edges and corners, the size and head of the dome must not be inverted; each dome foot should be consistent with the dome, and each dome brick should be hammered tightly (no hammer is forbidden), and every 3-5 rows should be checked. Prevent the upper and lower surfaces of the dome bricks from wrong teeth; the depth of the lock bricks into the dome is about 2/3 to 3/4 of the length of the entire dome brick, and the depth of the lock bricks on the same section shall be kept the same. When driving in the lock bricks, use a big wooden hammer; the temperature measuring hole bricks are left in an accurate position.
After the masonry kiln crown is completed, the bars should be tightened in time to remove all temporary fixings. Usually, the height of the block from the wooden mold tread is 0.15% of the block span, and the brace does not need to be too tight. According to experience, sometimes the brace is tightened until the big block is separated from the block mold, and the seam is 4-2mm. Before tightening the strip, make a plan for tightening the strip, make preparations for personnel, equipment, and tools, and assign experienced personnel to uniformly command. The number of buckles and intervals should be arranged in advance and explained clearly. If the bracing is too tight during the baking process, many defects such as peeling, missing corners, cracks and other defects on the inside of the bricks will affect the quality of the bricks, and the defective bricks need to be replaced. During the tightening process, observe the changes of the dam at any time, and deal with the abnormal situation in time. The tire mold can be removed when the bricks leave the tread 12 hours after there is no change. Finally, check the quality of the large slabs, the size of the head is upside down, the slabs are damaged and cracked, and the top joints are too large. They should be replaced and rectified in time.
In the actual construction, the lottery of the large slab refractory bricks after the kiln is baked also occasionally occurs. The cause may be that the size of the bricks is upside down and has not been checked; or the mud joints are too large during masonry; it may also be that the masonry of each row of bricks is not straight; it may also be that the appearance of the bricks is different in thickness. , The deviation is large, when the thicker bricks and the thinner bricks are laid in a row, the thinner bricks are the easiest to draw lots. Therefore, making a clear identification mark on the bulk of the brick is a good way to effectively prevent the draw. Even so, there are still one or two bricks with their heads upside down during each construction. So the final check is essential.
