Ventilation is a key part of tunnel construction. There is no wind in tunnel construction, so there is no gas flow, personnel structure, and no ventilation at all. Therefore, it is not possible to harm the staff at the vent or keep close to the ventilation plastic hose. It is possible to step on or touch the dangerous setting, and the accumulation of objects will affect the quality and effect of ventilation.

Regular inspection and disassembly of tunnel fans. Measurement of electric motor dielectric strength energy

It is divided into three or two color grounding resistance tests of terminal posts and indirect ground resistance tests between each terminal post and centrifugal fan casing.

The disassembly and installation inspection of the muffler shall consider the following regulations:

A. The glass fiber lining is smooth and clean without damage.

B. The surface of the perforated aluminum plate is cleaned, no rust, and the holes are not blocked.

C. The outer surface of the muffler is smooth and clean, without obvious pits, scratches and corrosion.

D. The screws of the muffler standard parts are evenly distributed, and the connectors are flat and cannot be loosened or dropped.

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E. The muffler must not be damaged or damp during transportation, and the filled muffler must not move down significantly.

Acceptance of tunnel fan embedded parts project:

a. Check whether the number of piles of embedded parts meets the design requirements.

B. Weld the connecting parts of the centrifugal fan with the embedded parts, load the embedded parts, and test the tensile force of the embedded parts.

C. Check whether the number and position of embedded parts meet the design and installation requirements. The error of embedded parts does not exceed the allowable error of centrifugal fan installation, that is, the offset of the axis plan is less than 10 mm, and the design elevation is less than ±10 mm.

D. In the marking work, the welding position of the RF connector on the embedded part should be clearly defined and marked. Welders should weld RF connectors to embedded parts and be certified for each job. After the centrifugal fan connector is accurately positioned, the DC welding machine is used for fixed welding, and the alkaline electrode E4315 is used; it is suitable for Φ3.2 welding wire, and the welding current is controlled at 80-100; when the Φ4 electrode is covered, the welding current is Controlled at 120-150, welding according to any document, there is no actual requirement h=12mm.

E. Connect several cooling fan connectors welded to the embedded parts to the galvanized steel wire rope, and connect them with an inverted chain. The total weight of the hanging object is 15 times that of the cooling fan and connecting accessories. Make a good steel support frame, put a barometer on it, and observe the changes of the embedded parts under the function of hanging objects. The time is set to 0.5h, 1h, 1.5h, 2h respectively, and it is accurately measured every 30 minutes. If neither the estimate nor the barometer changes, perform a static load test. According to the requirements, two or all groups can be appropriately selected for tensile testing.

Anti-corrosion solutions for welding of tunnel fan joints:

For welding cleaning, first apply anti-corrosion paint twice, and then paint gray black epoxy resin paint twice, with a paint thickness ≥ 60m.