Grid Brick

Grid brick is a type of heat storage material made of refractory materials, which achieves heat exchange function by setting regular grid holes in the brick body. It is mainly used in the heat storage chamber of blast furnace hot blast stove and the waste heat recovery system of glass melting furnace. Its structural features include parallel transparent grid holes, positioning convex groove design, good volume stability, excellent high-temperature load creep performance and other technical characteristics. The material is divided into clay bricks (<900 ℃), high alumina bricks, mullite bricks, silica bricks (>900 ℃) and other types according to the operating temperature, with a compressive strength of 35-55Mpa and a refractory temperature range of 1770-2000 ℃.
This technology has undergone iterative development of aperture specifications: in the early days, 40mm aperture standard bricks (heating area of 32.7m ²/m ³) were used, and later evolved to 30mm aperture (48m ²/m ³). Currently, the mainstream 20mm aperture specification (64m ²/m ³) has been applied to 5500m ³ blast furnaces in Cherepovets, Russia and 3200m ³ blast furnaces in Shandong, China. Innovative products include the 19 hole 25mm grid brick developed by Yuxing Company, which improves heat transfer efficiency to over 80% through pressure and flow equalization design, and achieves stable operation at 1250 ℃ in the 2922m ³ blast furnace of Hebei Iron and Steel [8-9]. The new magnesia alumina spinel lattice brick will be used at temperatures above 1900 ℃, gradually replacing traditional magnesia chrome materials to achieve chromium free production.
Basic characteristics
1. It has multiple transparent grid holes parallel to the side surfaces, as well as positioning protrusions and grooves located on two parallel surfaces.
2. Good volume stability, excellent high-temperature load creep performance, high density and low porosity. Modern blast furnace hot blast stoves usually adopt a lattice brick heat storage chamber structure.
heating area
The old type blast furnace hot blast stove uses standard grid bricks with a diameter of 40 millimeters and a heating area of 32.7 square meters per cubic meter. The Kalukin top fired hot blast stove was initially promoted with grid bricks with a diameter of 30 millimeters and a heating area of 48 square meters per cubic meter. The Kalukin top fired hot blast stove is promoting grid bricks globally, which are the earliest grid bricks with a diameter of 20 millimeters and a heating area of 64 square meters per cubic meter used and patented by Kalukin Company.
Purpose
Grid bricks are mainly used in blast furnace hot blast stoves and flame furnaces.
Grid bricks are mainly used in the heat storage chamber of hot air stoves. Grid bricks with grid holes are arranged in an orderly manner, and the upper and lower through holes of the grid bricks allow gas to pass through. According to the technical requirements of different temperature zones, siliceous lattice bricks, clay bricks, etc. are generally selected. In some hot air stoves, high alumina bricks, mullite bricks, silicate bricks, etc. are also selected.
The function of a hot blast stove is to heat the cold air sent by the blower to the blast furnace into hot air, which is then sent into the blast furnace through a hot air pipe for combustion reaction. The blast furnace hot blast stove has a burning period and a blowing period, which rotate between two working periods. During the burning period, the high-temperature flue gas after combustion passes through the holes of the grid bricks in the hot blast furnace, transferring heat to the grid bricks; During the air supply period, the cold air coming out of the blower enters the hot blast furnace, is heated into hot air by the grid bricks, and then sent to the blast furnace through the hot air pipe.