This method is suitable for the construction of general refractory castable within the scope of dry kiln, and the provisions are the preparatory work that should be done before the construction of general refractory castable, the welding of anchors, the placement of thermal insulation materials, the safety of wood molds, and the problems that should be paid attention to in the construction process, and some physical and chemical indexes and parameters of general refractory castables are attached.
1. Anchors
1. The anchors commonly used for refractory castable construction in dry kilns are all heat-resistant stainless steel (1gr18ni9ti), which are divided into three types according to their lengths: 25 4mm, 25 4mm, 25 4mm, and 25 4mm. Please refer to the relevant refractory drawings for the specific construction site of which anchor is used.
2. The anchor is generally processed by a whole heat-resistant stainless steel plate with a thickness of 4mm: 250mm, 280mm, and 300mmA rectangular strip with a width of 25 mm is then manually processed into a "Y" shape, and finally made by dipping asphalt on its head.
3. The welding of anchors should depend on the temperature of the part, and the kiln mouth is a pair of cloth every 200mm in the length directionThe grate cooler slope, girder and low wall are one pair of cloth per 300mm. Distances should be kept as consistent as possible to prepare for the placement of insulation.
Second, the placement of thermal insulation materials
1. In principle, the original drawing or the original thermal insulation material requires the placement of thermal insulation material to protect the shell steel structure.
2. Calcium silicate fiber insulation board with good thermal insulation effect should be used as heat insulation material as much as possible, especially some key parts.
3. When placing the thermal insulation material, it should be as large as possible, and the special binder provided by the manufacturer should be used to place it as full as possible.
4. Before fixing the net, the calcium silicate insulation board should be brushed with paint on one side of the refractory castable for waterproof purposes (the refractory castable is made with water as the substrate, and more attention should be paid to it).
5. When fixing the thermal insulation material, use a thin iron wire below 14, wrap it around the anchor to pull the net and fix it, and make it close to the steel structure.
3. The setting of the expansion joint
1. Regardless of whether the refractory castable is expanded or contracted by heat, expansion joints should be set.
2. The refractory castable is shrinked by heating, and the expansion joint can be made of plywood (or other materials that are not refractory and thin, and have a certain strength).The heating is expanded, depending on the size of the expansion, and then the material is selected to set the expansion joint. However, the refractory castable used in my dry kiln is generally contracted by heat.
3. The distance between the expansion joints is 15~2.0m。
4. When pouring refractory castables, grout should be grouting on both sides of the expansion joint at the same time to prevent the expansion joint from being pushed down by the slurry.
Fourth, molding
1. The template is generally made of wood mold, and a gap of 2mm is allowed.
2. After the mold is completed, the relevant project leader should inspect it, and the unqualified ones should be reworked immediately.
3. Before pouring, the wooden mold should be moistened with water to reduce the gap and facilitate the removal of the mold.
4. The small wooden strips used to support the wooden mold inside should be removed immediately without affecting the firmness of the wooden mold. Be sure to remove it during the pouring process at the latest.
5. The height of a mold can not exceed 1m, in order to facilitate vibration and construction quality, in order to ensure the progress of the beating and mold crossing.
5. Preparation before pouring
1. Confirm that the heat insulation material has been placed and fixed.
2. Confirm that the wood is well molded and firm.
3. The refractory castable should be stirred with a powerful mixer and vibrated with a rotary vibrating rod.
4. Confirm that the powerful mixer and vibrating rod are in place before pouring.
5. 10 25 mortar barrels should be prepared depending on the distance.
6. Confirm that all kinds of refractory materials are sufficient and in place.
7. Confirm that there is a special person responsible for weighing, measuring and adding high-alumina cementThere are also special personnel for gluing, and other slurry transfer personnel are also in place.
8. The personnel who hold the vibrator are required to be skilled and responsible, preferably migrant workers in this section.
Sixth, the construction vibration method
1. The general part adopts 35mm vibrating rod, which is convenient for construction and is also conducive to the refractory castable in placeHowever, some simple structures and straight parts can be vibrated with 50mm vibrating rods.
2. The vibration should be compacted, and the surface of the castable must be vibrated to produce slurry.