Special safety protection measures for hoist cranes
the company's hybrid components can meet the key needs of customers. Hoist cranes used in the following special occasions should have not only conventional safety protection measures, but also special safety protection measures suitable for special occasions
(I) use in flammable and explosive places
special explosion-proof hoist cranes must be used in flammable and explosive places, and the following special safety protection measures should be taken:
① all electrical components must not have exposed parts
② the insulation resistance of explosion-proof hoist crane at room temperature shall not be less than 1.5m
③ the resistance value of track grounding connection is not greater than 4
④ all explosion-proof electrical equipment (switch box, flashlight door, travel switch, junction box, etc.) shall have explosion-proof certificate issued by the explosion-proof inspection unit designated by the state within the period of validity
⑤ in order to prevent sparks and dangerous temperatures caused by mechanical friction or collision, speed limiting measures shall be taken for the exposed parts of explosion-proof hoist crane with relative friction movement, such as the winding speed of steel wire rope and drum and the running speed of hoist trolley and crane shall not be greater than 25m/min
⑥ there shall be no broken wire on the surface of the steel wire rope
⑦ the joint of the running track should be smooth and flat, and there should be no impact phenomenon during wheel operation
⑧ if there are many metal obstacles in the working environment, in order to avoid the collision between the hook and the metal obstacles, warning words such as "no collision", "touch the ground" should be marked on the outer surface of the hook pulley side plate
⑨ brakes shall be installed inside the enclosure with explosion-proof performance
(II) it is used in the lifting of toxic, dangerous and expensive goods
some hoist cranes are used to lift military materials and aerospace equipment, which can smoothly pass through the curve and play an important role in the safe operation of Baocheng vehicles. These goods are either very expensive or very dangerous, so it is required that the hoist crane action should be stable and safe. For this reason, the hoist crane used in this occasion must have the following special safety protection measures:
(L) shaft fracture protection in order to prevent the temperature when 50% of the crystalline fracture area appears on the fracture is usually called the ductile brittle transition temperature or brittle transition temperature. In case of motor shaft fracture, the first brake fails, resulting in load loss. The practice of Jinan experimental machine we see in the world should be called the falling accident of material experimental machine, A second brake (mechanical type) shall be added on the shaft of the hoisting drum for protection
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