Design ideas and steps of the lattice of the hotte

Design ideas and steps of glass furnace lattice

① lattice design is one of the important contents of glass furnace design. In the lattice design, although it is easy to set the preheating temperature of combustion supporting air, it is difficult to say whether the preset preheating temperature of combustion supporting air can be reached in the operation after the completion of the furnace. When other conditions are met, the preheating temperature of combustion supporting air depends on the actual heat exchange capacity of the regenerator lattice: the lattice should have sufficient heat storage capacity, appropriate heat exchange area, and the inherent total heat transfer coefficient determined by its own structure

② if the heat exchange area of the lattice is insufficient, it will certainly not reach the envisaged preheating temperature of combustion supporting air, but it is not that the larger the heat exchange area of the lattice, the better. Even if the heat exchange area is appropriate, if the physical structure of the lattice is unreasonable, such as the plane size of the lattice is large, but the height is insufficient, which belongs to a squat shape, there will be uneven flow distribution of flue gas and combustion supporting air in the lattice holes. Even if the path of some flue gas and air flowing through the lattice is different, it is inevitable that the heat of flue gas cannot be transferred to the combustion air as required, so that the set preheating temperature of combustion air cannot be reached

③ the longitudinal size of the regenerator should obey the distribution size of the small furnace, so that it can be connected with each small furnace correspondingly. Because the lattice holes at the corresponding position of 1 small furnace are prone to dust blockage, it is necessary to extend the regenerator to the direction of the kiln head appropriately, and the difference in the experimental speed will clearly affect the long experimental consequences, so as to increase a certain number of reserve lattice holes. The length of the regenerator room is usually about 1m shorter than the melting zone of the furnace. The width of the regenerator room should be determined according to the width of the molten pool and the type of lattice bricks. For cylindrical bricks, 35% - 40% of the width of the molten pool can be selected; For strip bricks, 40% - 45% shall be selected

④ the heat transfer of flue gas to lattice bricks during the exothermic process in the lattice includes convective heat transfer and radiant heat transfer, which is the sum of these two heat transfer; During the heat absorption process of the combustion air in the lattice, the lattice brick only considers the convective heat transfer of the combustion air, and the radiant heat transfer of the air is very small, which can be ignored

⑤ in the calculation of the heat exchange area of the lattice, the temperature difference between the flue gas and the combustion supporting air is also one of the variables. Because the temperature of the flue gas and the combustion supporting air in the regenerator lattice changes with a nonlinear law, this calculation method adopts the logarithmic average temperature difference calculation, which is more in line with the actual heat transfer situation of the lattice

⑥ when the lattice is arranged in the regenerator cavity, the longitudinal gap between the lattice and the cavity wall is often too large or too small. Therefore, the regenerator cavity size needs to be slightly adjusted in combination with the number of holes in the lattice, the position of the partition wall, the span of the grate arch, etc., so that the longitudinal gap size is maintained at 30 ~ 40mm

⑦ the lattice with excellent design has the advantages of less investment and long service life, and can improve the preheating temperature of combustion supporting air as much as possible

steps of lattice design

the focus of regenerator design is lattice design. The use of "simplified formula" to design glass led to a sharp decline in the export amount of extruder in March; With the gradual weakening of the impact of the financial crisis on the world economy, the lattice of the regenerator of the glass furnace is a more accurate and advanced method. The design can be divided into three steps:

leading step, basic data calculation: ① calculate the amount of combustion supporting air required per unit time and the amount of flue gas produced in the operation of the furnace; ② Calculate the heat balance of the regenerator to determine the preheating temperature of combustion supporting air and the temperature of exhaust gas, which are locked with each other; ③ Select the type, specification and arrangement of lattice bricks; ④ Select the regenerator cavity type: one of full connection, combined connection and full separation; ⑤ Determine the longitudinal and transverse dimensions of the regenerator cavity plane; ⑥ Calculate the total gas flow area in the regenerator lattice on one side of the furnace; ⑦ Calculate the velocity of combustion supporting air and flue gas

step 2, calculation of the heat transfer coefficient of the lattice: ① calculate the heat transfer coefficient of the upper end of the lattice, including the heat transfer coefficient of the combustion supporting air ejected from the upper end of the lattice and the heat transfer coefficient of the incoming flue gas, and calculate the comprehensive heat transfer coefficient of the upper end of the lattice according to the wall thickness, bulk density, thermal conductivity, specific heat capacity, reversing time and other parameters of the upper end of the lattice brick; ② Calculate the heat transfer coefficient at the lower end of the lattice, including the heat transfer coefficient of the cold air entering the lower end of the lattice and the heat transfer coefficient of the exhaust gas, and calculate the comprehensive heat transfer coefficient at the lower end of the lattice according to the parameters of the lattice bricks at the lower end and the reversing time; ③ Finally, according to the comprehensive heat transfer coefficient of the upper and lower ends of the lattice, the total heat transfer coefficient of the lattice in the regenerator on one side of the furnace is calculated on average

the third step is the overall design of the lattice: ① calculate the logarithmic temperature difference between the combustion air and flue gas of the circuit aid switch; ② Calculate the heat exchange area required by the lattice of one-sided regenerator; ③ Calculate the height and size of the lattice; ④ Determine the number of layers of the lattice; ⑤ Configuration of lattice bricks in the whole kiln