When building a shielded room, there are three aspects to be considered in the design of the shielded shell. The editor of the shielded room manufacturer will introduce the main considerations during construction:
(1) Steel plate shielded room structure
The steel plate shielding machine room is made up of different specifications of modular steel plates (steel plate thickness 2~3mm) interconnected into a whole. According to the different bearing capacity of different parts of the shielding shell, the rectangular steel keel with different cross-sectional area is designed and manufactured as the supporting gantry frame of the shielding shell. Its biggest feature is rigidity, seismic resistance, stability and reliability. It is better than other structural shielding. Room, and the shielding effectiveness is much higher.
(2) Selection of steel plate shield material
Electromagnetic shielding refers to the shielding of electromagnetic waves, while electrostatic shielding refers to the shielding of electrostatic fields. Electrostatic shielding requires that the shield must be grounded. It is not the grounding of the shielding body that affects the electromagnetic shielding effectiveness of the shielding body, but the continuity of the shielding body's conductivity. Factors that destroy the conductive continuity of the shield include seams and openings in different parts of the shield. Therefore, electromagnetic shielding has stricter requirements on the conductivity of the shielding body than electrostatic shielding.
According to the analysis of the relative conductivity, relative permeability, absorption loss, reflection loss and other coefficient values of different materials, the shielding body of the shielding room chooses iron-based metal materials, and generally adopts steel plates with a thickness of zmm. The ground is made of the same material, generally 3mm thick steel plate. Considering the shielding effectiveness of the shielding material and also taking into account the overall mechanical performance of the electromagnetic shielding room, the design requires steel plate unevenness ≤ 4mm/m2, shielding verticality ≤ 10mm, and shielding seismic resistance ≥ 8.
(3) Connection mode of steel plate shielded computer room
The steel plate shielding machine room includes a steel plate welding type electromagnetic shielding machine room and a steel plate assembled electromagnetic shielding machine room.
1. The steel plate welding electromagnetic shielding machine room with welding connection
The shielding body raw material (steel plate) is processed into unit modules, and continuous welding (carbon dioxide or other gas shielded welding) is used for on-site installation. It is characterized by narrow welding hot zone, small deformation, tight welding seam, and no melting on the surface Scum. Ensure that the shielding effectiveness at the joints of the module board of the shielding layer is consistent with the shielding effectiveness of the shielding layer of the entire unit, and at the same time improve the galvanic corrosion resistance of the weld. Electrochemical corrosion will reduce the shielding effectiveness and the intermodulation effect, because the compound produced by the electrochemical reaction is a non-linear semiconductor material, which will produce signal mixing, leading to the generation of new interference frequencies.
According to the different bearing capacity of different parts of the shielding shell, rectangular steel keels with different cross-sectional areas are designed and manufactured as the reinforcement support of the shielding body. The keel is welded with a 30mm×40mm rectangular tube attached to the inner wall of the shielding body steel plate.
2. Steel plate assembled electromagnetic shielding machine room with screw connection
Steel plate assembled electromagnetic shielding room: The six-panel body is a unit module made of cold-rolled steel plate with a thickness of 1.5mm, which is assembled by M8 galvanized bolts, nuts, gaskets and conductive gaskets after galvanizing and plastic spraying. The six-panel body and the shell are insulated from the ground.