Q:Who knows what is the standard of insulation material whose fire proof is level A?

Level A is distinct from B in coefficient of fire proofing. Level A is non combustible, while Level B is divided into B1( flame retardant), B2(combustible) and B3( inflammable). Currently in the market, level A materials are as follows: phenolic, rock wool, insulation mortar, ceramic foam, foam glass, and foamed concrete. The most advantageous of level A material at present is foamed concrete, also known as foamed cement. Xuzhou Lvchuang Construction company is working on this, you can search fro it on the internet, it has high cost performance.

Q:How long is the fire endurance of Grade A fire resisting shutter

The fire endurance of Grade A fire resisting shutter is not lower than 1.20h. Use fire resisting shutter as fire?compartment separation in places where it is difficult to set firewall. When fire resisting shutter whose unexposed surface temperature rise is used as judging condition of fire endurance is used, its fire endurance should not be lower than 3h. When fire resisting shutter whose unexposed surface temperature rise is used as judging condition of fire endurance is not used, individual protection of ?closed automatic water spray system shoule be set at two sides of the shutters and duration of water spray system should not be less than 3.0h.

Q:What does refractory mean?

What is refractory material?Refractory material generally refers to the inorganic refractory degree over 1580oC non metallic materials. It includes natural ore and various products in accordance with certain requirements after a certain process. With the volume stability of high temperature mechanical properties, a good, is the necessary equipment for all kinds of high temperature materials.

Q:Which kind of furnace hearth refractory is better?

hearth selected material] hearth material must be durable, high temperature resistant, general selecting masnory made of refractory cement, silicon carbide refractory products, mullite or multicrystal mullite (which is the general term of minerals composed of a series of aluminum silicate, mullite is only stable binary compound in the Al2O3-SiO2 system) etc.. [hearth] is a three-dimensional space surrounded by furnace walls for combustion of the fuel. The funtion of hearth is to ensure the fuel to burn as far as possible, and to cool the gas temperature of the hearth exit to the allowed temperature of convection heating surface safe operation . Therefore, the hearth should have sufficient space and adequate heating surface. In addition, there should be reasonable shape and size in order to fit the burner and the organize aerodynamic field inside the furnace to prevent the flame from adherence, dashing walls and have high fullness and eve wall thermal load.

Q:About the use of horseshoe glass kiln refractories

the lower portion of advanced clay brick, the lower portion of magnesia-chrome brick arch - high-purity silica brick; flue - clay brick; breast wall--33 # fused zirconia corundum brick (with shrinkage); fused zirconia bottom --33 # fused zirconia corundum brick (with shrinkage); regenerative chamber- the upper part of sintered magnesia-chrome brick, cooling section 33 # electric?smelting no shrinkage fused zirconia corundum brick; the wall - the melting section 41 # no shrinkage fused zirconia corundum brick (including 41% of zirconium; the lattice- superstructure of high purity magnesia brick, the same below); small stove --33 # fused zirconia corundum brick (with shrinkage). It can be said that it is the maximum configuration, if the funds is limited it can be downshift appropriately.

Q:What is unshaped refractory?

Concrete。 Early concrete technology appears, it is not forming products in the heat furnace, some parts such as pit heating furnace furnace wall, rotary kiln mouth ring, cutting slope and discharge chamber wall, etc., are able to design large masonry (top heating block weighing 3-4 tons) made concrete. Concrete cattle production method is to pour the material into the model, vibration molding, after the release of heat treatment, to provide users in addition to large blocks, weight, in use, and machine pressure brick no essential difference. The amount of water used in the casting material produced by the manufacturer is less than 10% above that in the field, and the processing quality is good and the quality is stable. As the bricks are large and heavy, the site shall have lifting equipment. As long as the site can be hoisted, the concrete shall be used as far as possible, or smaller ones, and some people can lift it. Concrete does not require the user to do a special heat treatment, this point is very meaningful.

Q:How long is the fire-resistant time of fireproof wooden door?

National standards define the fireproof door as class A, class B, class C, among which fire-resistant time of class A fireproof door should not be less than 1.5 hours, class B should not be less than 1 hour and Class C should not be less than 0.5 hours.

Q:How many levels are there in the classification of PP fireproof materials?

PP fireproof materials level V-0: After two 10-second fame tests on the sample, the flame extinguishes within 30 seconds. Inflamer can not drop. V-1: After two 10-second flame tests on the sample, the flame extinguishes within 60 seconds. Inflamer can not drop. V-2: After two 10-second flame tests on the sample, the flame extinguishes within 60 seconds. Inflamer can drop.

Q:What is the the best ratio of mortar in refractory cement?

The ratio of refractory cement are: M10 the ratio of cement and mortar: cement: Sand= 346kg: 1631kg M7.5 ratio of cement and mortar: cement: Sand =274kg: 1631kg M5 The mix proportion of cement and mortar: cement: Sand = 209kg: 1631kg M10 mix proportion of composite mortar: cement: Sand: Lime =306kg: 1600kg: 29kg M7.5 mix proportion of composite mortar: cement: Sand: Lime =216kg: 1600kg: 64kg M5 The mix proportion of composite mortar: cement: Sand: Lime =205kg: 1600kg: 100kg

Q:What is the most reasonable drying heating curve of magnesia refractories? Products of less than 0.5T

You'd better oxidize magnesia preformed unit at room temperature for a longer period of time, then bake it, during which, it's enough to control the maximum temperature within 300 degrees. During the middle process, usually heating up for 4 hours and keep warm for 3 hours. The entire heating up process takes about 20 hours. If it is the site operation magnesia-based castable, it should be heated slowly in the early stage, and pay attention to keeping warm at 80 degrees Celsius. Every manufacturers has their own heating curves, so do not blindly adopt existing curves, try to make your own heating curve.