The first part is series code M, the first prefix of the pinyin of coal.
The second part is the use of characteristic code, reflecting the occasions used by the cable. The meanings of the letters are as follows: C, for coal mining machine; D, for low-temperature environment; M, cap lamp; Y, for coal mining equipment (moving); Z, for electric drilling.
The third part is the structural feature code, indicating the structural characteristics of the cable. The meanings of the letters are as follows: B, weaving strengthening; J, with monitoring core; P, non-metallic shielding; PT, metal shielding; Q, lightweight;
The fourth part is the material feature code, E is used to indicate that the insulation or sheath is made of elastomer material. This part is omitted when rubber and insulation are used. E, elastomer material.
The fifth part is rated voltage U0/U(KV).
The sixth part is the representation of the number of power cores * nominal cross-sectional area. The two are connected by a multiplication sign and the unit is square millimeters.
The seventh part is the representation of the number of ground cores* nominal cross-sectional area. The two are connected by a multiplication sign and the unit is square millimeters.
The eighth part is the representation of the number of auxiliary cores * nominal cross-sectional area. The two are connected by a multiplication sign and the unit is square millimeters.
The fourth part and the fifth part are connected with "-"; the sixth part, the seventh part and the eighth part are connected with "+".
Mine cable fire performance analysis and engineering application As the increase of wire and cable, the concentration of laying, the poor quality of construction, etc., exacerbated the risk of wire and cable fire. Therefore, to prevent wire and cable fires in practical engineering applications, it is necessary to start with the control of risk factors and apply relevant regulations to take corresponding fire prevention measures.
A wire and cable and the cause of the fire is mainly because the characteristics <br> <br> overload, short circuit, excessive contact resistance and external heat sources. Short circuit, local overheating and other fault conditions and external heat, wire and cable cause fire causes. Insulation data reduces insulation resistance, loses insulation, and even burns, causing fire. The main characteristics of the wire and cable during a fire are as follows: In the case of a fire, the fire temperature is generally 800°C to 1000°C. The wire and cable will soon lose their insulation ability, which will cause secondary electrical accidents such as short circuit, which will cause greater losses; 2 The wire cable will have greater overload capacity under the specified allowable ampacity; the wire and cable will cause insulation data to melt in an instant , combustion, 3 short circuit conditions. And ignite the surrounding combustibles.
2 Analysis of fire resistance of electric wires and cables 2.1 Analysis of fire prevention mechanism 2.1.1 Flame retardance mechanism The flame retardant in the condensed phase is decomposed to absorb heat and the heat of combustion reaction. Slowing down the temperature rise in the condensed phase, delaying the thermal decomposition rate of the data; releasing a chain reaction radical blocking agent, 2 after the flame retardant is decomposed by heat. The flame and chain reaction branches are interrupted and the gas phase reaction rate is slowed. The formation of a coking layer or a foam layer enhances the effect of these layered hard shells on blocking the heat transfer. 3 The catalytic coacervation phase thermally decomposes the solid phase products. The flame retardant undergoes an endothermic phase transition, under the influence of 4 heat. Physically prevents the temperature in the condensed phase from rising.
2.1.2 Fire resistance mechanism Reduce the amount of heat generated by the polymer. Add an additive to the wire and cable insulation and sheathing data. Prevents the decomposition of polymers or promotes the insulation of the insulation and sheathing material to form a maintenance layer; after insulation and sheathing layers are ignited by fire, an inorganic insulating material such as mica glass ribbon is added at the 2nd core. * The mica fireproof belt wrapped around the conductor is maintained and continues to be energized so as to maintain normal operation for a certain period of time during a fire.
2.1.3 Mechanism of Mineral Insulated Cables AlOH3 is 34.6% under high temperature operation. The absorption effect of metal hydrate makes the cable flame retardant. For example: AlOH3 and MgOH as flame retardants. The MgOHz is 31%, and the reactions shown in Reaction Formula 1 and Reaction 2 are decomposed into endothermic reactions, so that the combustion of the high polymer can be suppressed. 2AIOH3--*Alz03+3H20-2648KJ1MgOH2--MgO+H20-93.3KJ2
The mechanical concealed cistern is a common bathroom fixture that stores flush water and controls flushing. It is usually installed in the wall, and there is only a button on the outside to start the flush. Its design makes the water tank no longer occupy the toilet space, thus providing more free space and beautiful appearance.
Space-saving: The design of the mechanical hidden water tank allows the water tank to be installed inside the wall, saving valuable bathroom space, providing more free space and a beautiful appearance.
Beautiful: The design of the hidden water tank makes it no longer stand in the bathroom like the traditional surface-mounted water tank, thus improving the overall aesthetics of the bathroom.
Water saving: The mechanical hidden water tank can precisely control the water volume when flushing, avoiding excessive consumption of water resources, thereby reducing water usage and saving water bills.
Long service life: Compared with the traditional surface-mounted water tank, the mechanical hidden water tank has a longer service life and lower maintenance costs because it is more concealed and less susceptible to external factors.
More hygienic: The traditional surface-mounted water tank needs to be cleaned frequently, and the scale and sundries hidden inside the water tank are not easy to be polluted by the outside world, so it is more hygienic.
Mechanical Concealed Cistern, Concealed Flushing Cistern, Toilet Flush Tank, Build In Toilet Cistern
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