Views:9 Author:Site Editor Publish Time: 2018-08-16 Origin:Site
The main load of the gas cylinder is internal gas pressure, wind load and earthquake action. The wind vibration coefficient should be considered in wind loads. The wind load shape coefficient of the high pressure spherical tank can generally be 0.30 to 0.35. The horizontal seismic action of the wet tank includes the seismic force generated by the sink and the weight of each tower, and the hydrodynamic pressure caused by the vibration of the water in the tank. The horizontal seismic action of the dry tank includes the self-weight of the barrel and the seismic force generated by the weight of the piston. When calculating the snow load, the eccentric moment caused by the local accumulation of snow at the top of the tank should be considered.
Under the action of various loads and internal pressures, the inner wall of the shell wall and the top plate of the tank are analyzed according to the theory of the thin shell structure without moment. The thickness of the wall and ceiling of a low pressure gas cylinder is generally not determined by strength, but by construction and corrosion protection requirements. The guide column of the guide column type gas cylinder is subjected to the wind force and the horizontal seismic force on the tower section transmitted from the guide wheel, and the pressure of the guide wheel can be decomposed into the respective planes according to the plane truss analysis method, and the internal force of the rod member is obtained. The inner column, the upper and lower ring plates and the guide rails on the spiral guide type gas cylinder tower section form a space frame, and are subjected to the horizontal load of the wind load and the seismic force transmitted from the guide wheel. The cylinder of the dry gas cylinder shall be checked for local and overall stability under the action of wind load, horizontal seismic force and internal pressure. Spherical tanks have strong tensile strength under internal pressure, but their stability is poor under negative pressure. Therefore, it is necessary to specify the minimum use pressure to ensure that negative pressure does not occur when the temperature drops and the internal pressure decreases.
When making a low-pressure gas cylinder, the tank is divided into several parts and prefabricated in the processing plant, and then the on-site total installation is performed, which reduces the on-site installation of the weld. Strict inspections are required from the stakeout, production, and overall installation stages to ensure the final overall accuracy. When installing the tank of the dry tank, firstly weld the bottom plate, assemble the piston on the bottom plate, and support the top truss on the piston to weld the top plate. At the same time, the bottom of the tank is the last section of the wall and column. Then, it is blasted under the piston to raise it, and the piston is used as a construction platform to install the upper panels. Lift the pistons one by one and install the columns and siding section by section. After the design height is reached, fix the tank top truss and the top column, then lower the piston and complete the installation. Large-volume high-pressure gas cylinders can be welded on site using pre-compressed block plates. After welding, all welds are subject to quality inspection.