The total height of the chimney is 60 meters, single flue, with an inner diameter of 2.5 meters at the top, and the minimum flue gas temperature is 400°C. The seismic fortification intensity is 7 degrees, and the basic wind pressure is 0.5 KN/square meter. The brick masonry for the cylinder wall uses MU10 bricks, with fire-resistant mixed mortar M7.5. The chimney lining is 37 meters high, constructed using ordinary water-resistant bricks and fire-resistant mortar. The steel structure requires anti-corrosion treatment.
Construction Plan:
(1) Brick chimney construction using internal climbing scaffolding.
The internal climbing scaffold is formed by inserting steel pipes into the exterior of the chimney wall and laying wooden boards on top to form a working platform. After each level of bricks is laid, the climbing rods are shifted downward, and the working platform moves up one step.
1. Internal climbing rods consist of 8 steel pipes with diameters of 73mm and 60mm. These are grouped into 4 retractable climbing rods. When moving the working platform upward, only one set of climbing rods is installed at a time. Once the appropriate height is reached, the second set of climbing rods is installed, then the upper scaffolding is moved upward, and the first set of climbing rods is removed to be reused at a higher level. The climbing rods should be inserted into the wall approximately 10 cm deep, neither too loose nor too tight, ensuring safety and ease of installation.
2. Safety net frames made from lightweight steel are installed at intervals of about 1 meter. The safety nets are woven from nylon ropes. As the inner diameter of the chimney changes minimally, a vertical ladder can usually be used to tighten the safety net frame with steel wire ropes as it ascends along with the working platform.
3. Hoisting ladders are used to move the climbing rods and scaffolding planks. Workers can hang the hoisting ladder onto the next level of climbing rods, secure their safety harnesses, place the hoisting ladder plank, and stand on it to perform operations.
4. Ladder guardrails are installed for worker safety when ascending or descending the ladder. Wooden poles or logs are bound around the entire height of the ladder for protection.
(2) Material lowering using a well-type scaffold:
A material unloading platform equipped with an inverted chain hoist is attached to the well-type scaffold. Its position is kept slightly higher than the masonry work point to reduce the effort required to move large hoisting frames on the climbing rods.
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