Prefabricated Building Adaptation: Brick Machine Parameter Control Techniques for High-Precision Hollow Brick Production
With the rapid development of prefabricated buildings, the precision requirements for wall components have jumped from centimeter-level in traditional construction to millimeter-level. As the core material of prefabricated walls, the parameter control of brick machines during the production process of high-precision hollow bricks directly determines the component quality and assembly efficiency. How to achieve high-precision production of hollow bricks through refined parameter management has become a key issue for the industry's transformation and upgrading.
I. Parameter Feedforward Control in the Raw Material Preparation Stage
The production of high-precision hollow bricks begins with the standardized processing of raw materials. The control of brick machine parameters should not be limited to the forming stage but should extend forward to the raw material preparation stage. First, the speed of the hammer crusher in the crushing process should be controlled between 980-1050 r/min to ensure that the particle size of shale or coal gangue is ≤1.5mm, creating a prerequisite for subsequent homogenization. Secondly, the material distribution parameters in the aging chamber are crucial. When using a herringbone stacking method, the thickness of each layer should be ≤300mm, the moisture content should be controlled within the range of 12%-14%, and the aging time should be no less than 72 hours to ensure thorough homogenization of the raw materials. Finally, in the fine crushing stage of the roller mill, the roller gap should be precisely adjusted to 1.0-1.2mm. At this point, the fineness modulus of the raw material can be stabilized between 1.8-2.0, providing a material basis with a reasonable gradation for the molding process.
II. Coordinated Control of Core Parameters in the Molding Process
Molding is the core process for controlling the precision of hollow bricks, involving the coordinated optimization of multiple parameters such as extrusion pressure, vacuum degree, extrusion speed, and die temperature. The extrusion pressure setting needs to be dynamically adjusted according to the plasticity index of the raw material. When the plasticity index is between 13-17, the main extrusion pressure should be controlled between 2.8-3.2MPa, and the pressure fluctuation should be stabilized within ±0.1MPa. Vacuum degree is a key parameter for eliminating internal defects in brick blanks. The vacuum chamber vacuum degree should be ≥0.092MPa to ensure that the density uniformity deviation of the brick blank is ≤1.5%. The matching of extrusion speed and die temperature directly affects dimensional stability. When the extrusion speed is set to 1.2-1.5m/min, the die heating temperature should be maintained at 45-55℃, with a temperature gradient ≤3℃, which can effectively control the brick blank shrinkage rate within the target range of 0.4%-0.6%. The linkage control of the auger speed and feed rate is also crucial; the deviation between the two should be controlled within ±2% to avoid density stratification caused by uneven feeding.
III. Precision Maintenance Strategies in the Drying and Firing Process
Improper control during the drying and firing process of the brick blanks will completely negate the precision gains achieved in the forming stage. A stepped heating curve should be used in the drying process, with the inlet temperature controlled at 80-100℃ and the final temperature increased to 110-120℃. The circulating fan frequency should be set to 35-40Hz to ensure a drying shrinkage rate ≤0.3%. In the firing process, the temperature gradients of the tunnel kiln in the preheating, firing, and cooling stages need to be precisely designed. The heating rate in the preheating stage should be controlled at 1.0-1.5℃/min, the firing zone temperature should be stabilized at 980-1020℃ with a temperature difference not exceeding ±10℃, and the holding time should be 40-50min to ensure that the firing shrinkage rate remains stable between 0.2%-0.3%. The kiln car running speed and pushing cycle must be strictly matched, with a cycle deviation not exceeding ±5min, to prevent fluctuations in the kiln temperature field from affecting the product dimensional consistency.
IV. Intelligent Monitoring and Closed-Loop Optimization
Modern brick-making systems have the capability for real-time parameter monitoring and closed-loop control. Key parameters such as extrusion pressure, material moisture content, and molding temperature are collected by online sensors. PID control algorithms are used to automatically correct these parameters, controlling dimensional deviations within ±0.5mm. Regularly inspecting the die wear condition and promptly repairing or replacing the die when wear exceeds 0.3mm is essential for maintaining long-term accuracy. It is recommended to establish a "parameter file" for each type of hollow brick, storing the optimal parameter combination for each batch for direct reference during subsequent production, reducing precision fluctuations caused by manual machine adjustments.
In summary, the production of high-precision hollow bricks is a systematic project requiring meticulous parameter control across the entire chain, from raw materials, molding, drying to firing, and closed-loop optimization through intelligent monitoring. Only in this way can the stringent precision requirements of prefabricated buildings for wall components be met, driving the industry's transformation from "experience-based production" to "data-driven" intelligent manufacturing.
