Q:Detailed description of magnesia dolomite refractory material?

The use of low chromium or chrome free refractories is more and more widely used, developed countries in the development of chrome free refractories to replace the chromium containing material, through research and production practice show that dolomite refractories is the refining of AOD furnace, large cement kiln ideal material.

Q:What's the fire resistance test method of doors and roller shutters?

Fire resistance test method of doors and roller shutters: This standard specifies the fire resistance test method for roller shutter doors under standard fire conditions. The method is used to test the fire resistance of the ventilating duct when bearing the external fire (A duct) and internal fire (B duct). Fire resistance test of vertical ducts may be conducted referring to this standard. 1.Test specimen1.1 The test specimen is obtained by cutting from any part of the qualified metal tube unless otherwise relevant standard or mutual agreement specifies the cutting position of the metal tube. 1.2 Length of the specimen: L≈2.5D+50mm (D: outer diameter of the metal tube). The cut surface of the specimen must be perpendicular to the axis of the metal , and the seamed edge of the cut should be round off. Test method GB243-82 of metal tube necking 2. Test procedures 2.1 In the test, punch or press the metal tube into the tapered conical seat (see Figure) with a hammer or press machine, and make it uniformly diminished to the regulated shrinkage X which is calculated according to the following formula: Test method GB243-822 for metallic pipe necking: The inner wall of the seat cover used in the test should be polished, and has certain hardness and is coated with lubricating oil. Its conicity is 1:10, 1:5 or others in accordance with relevant standard provisions. If there is no provision, then adopt the conicity of 1:10. This standard is not suitable for: a) The pipeline whose fire resistance depends on the fire resistance of the ceiling; b) The pipeline with access door, unless otherwise the access door is included into the pipeline and tested together; c) The pipeline with two or three sides; d) Fume exhaust pipes;

Q:whether the fire resistant level of aerated concrete building blocks can reach the grade one?

the fire resistant level of aerated concrete building blocks can reach the grade one level. Aerated concrete strength grade shall be divided according to the concrete cubic compressive strength value. Use the symbol C and the cube compressive strength value (in N / mm2 or MPa gauge) to express. According to GB50010-2002 "concrete structure design specifications" provisions, ordinary concrete is divided into fourteen levels, namely: C15, C20, C25, C30, C35, C40, C45, C50, C55, C60, C65, C70, C75, C80 .

Q:Does hardware construction materials contain refractory?

refractory includes one kind of building materials. It is a special material and not commonly used.

Q:What are grade classifications of the external walls fireproofing material?

1. The thermal insulation material of level A combustion performance: Rock wool, glass wool, foam glass, foamed ceramics, foam cement, hole-closed perlite, etc. 2. combustion performance is level B1 insulation materials: Extruded polystyrene board (XPS) after special treatment / Special treatment of polyurethane (PU), phenolic aldehyde and gelatine powder polyphenyl granule 3 combustion performance is level B2 insulation material: Molded polystyrene board (EPS), extruded polystyrene board (XPS), polyurethane (PU), polyethylene (PE), etc.

Q:How to choose the material of refractory?

Long using temperature of aluminum oxide fiber is 1400 ℃, containing chromium aluminum silicate fiber, quartz, high purity aluminum silicate fiber, long-term use of temperature is 1000-1200 ℃ has aluminum silicate refractory fiber according to different raw materials, advanced refractory fiber (such as alumina. Commonly used vitreous aluminum silicate refractory fibre is amorphous, zirconium oxide refractory fibre) using temperature is 1700 ℃ view as >and the best temperature is 1300 ℃. Crystalline refractory fiber are polycrystalline mullite fiber, including ordinary aluminum silicate fiber, alumina and graphite refractory fiber, etc. The use of common refractory fiber temperature is 1150 ℃;>

Q:The manufacturing technique of refractory material

Melt blowing method is to melt the ingredients first, In addition, hiphotos, organic impurities, to be mixed, add sulfite pulp waste liquid into magnesia billet , ensure the accuracy of the product dimension. The products are mainly used for light refractory. then dry and fire with sintering to reduce the firing shrinkage of products, making it disperse into fiber or hollow sphere. The porpose of pre sintering raw material is to Sintering method is pre-sintering part of the raw material into clinker. such as adding binding clay into aluminum silicate blank

Q:What are the differences between first-level fire-resistant materials and second-level fire-resistant materials?

The combustion performance of materials could be divided into: A( noninflammability), B1(flame retardancy), B2(flammability), B3(inflammability). Building materials are divided into four ranks according to these properties. 1. In accordance with Code for Design of Building Fire Protection(GBJ16-1987)(revised edition in 2001), fire hazards in producing and storage can be divided into five types. In Fire Prevention Code of Petrol Chemical Enterprise Design(GB50160--1992)(revised edition in 1999), classification of fire hazards is also achieved according to the hazards of materials that have been using, producing and storing. Measures in prevention of fire explosion could be taken from the perspectives of fire separation, fire resistance level of structures, allowable floors, safe evacuation, and fire extinguishing facilities based on different levels of fire hazards. 2. Four fire resistance rating of buildings are listed in the book Code for Design of Building Fire Protection. And specific stipulations are made to the fire resistance of main elements of buildings, such as bearing walls, beams,pillars, and floors. When designing a building, if permitted, refractory materials of high-rank should be adopted in those buildings which have high potential fire hazard and a lot of combustible material and valuable equipment. While making sure fire resistance rating, the duration of fire resistance of each elements should meet its requirements.

Q:What is the acceptance standard of refractory?

It depends on the variety of materials. In general the main test items include chemical composition, refractoriness, refractoriness under load, creep, volume density, linear change, strength, slag resistance, thermal conductivity and thermal expansion. If it is shaped products, it is required to inspect the size deviation and whether it has edge. Detection method accords with the relevant national standards and there are lots of them. You can refer to the standard compilation.

Q:What are first rate fire resistant window materials?

class A window not less than 1.2 hours, class B window not less than 0.9 hours, Class C window not less than 0.6 hours. technical requirments: 1, materials and accessories (1) the window frame is made with a certain strength sufficient to safeguard the integrity and stability of the steel frame or wooden frame. (2) steel frame and mound layer can choose the galvanized steel plate or stainless steel plate. Its selection standards is in line with GB12955 "Steel Fireproof Door General Technical Condition" provisions of Article 5.1. (3) wood frame and mound layer material selected from the standard should be consistent with GB14101 "General Technical Conditions of Wooden Fireproof Door" in the provisions of Article 5.1.1. (4 ) steel, wood frame the inside filler material should be incombustible material. (5) fireproofing glass can be used without affecting the fire windows fire resistance test approved product. light transmittance of glass should not less than 75% of commom sheet glass which is the same number of layers. ( 6) a sealing material between the frame and the fire-resistant glass flame retardant materials should be used, which can play the role of fireproofing and smoke insulation in case of fire (7) hardware fitting should be tested as approved supporting product