The production process of fired bricks is quite strict. If there is a problem in one link, it can lead to a decrease in the quality of the bricks, and in severe cases, the entire batch of bricks cannot be used. Among them, the moisture removal and drying work of the brick blank is one of the details. Proper use of this method can greatly improve the quality of the finished product. The following are specific methods and precautions, hoping to be helpful.
The moisture removal and drying process of fired brick body mainly involves removing moisture from the body, which includes the moisture removal and drying stages. The drying stage is mainly the drying stage, which is further divided into several stages such as heating, constant speed drying, reduced speed drying, and equilibrium. Moisture removal is mainly carried out by air flow at room temperature to remove moisture on the surface of the billet that is greater than the humidity of the air. Generally speaking, this stage is relatively short. Tunnel kilns generally use a drying chamber for moisture removal and drying, using waste heat air from the preheating zone for moisture removal and drying. The airflow direction is exactly opposite to the direction of the bricks entering the kiln, and the high-temperature air first enters the brick boundary during the drying equilibrium stage. This requires a high temperature, flow rate, and speed of the gas passing through the preheating zone. Firstly, an appropriate amount of coal is required. Generally, the heat of the bricks is controlled at 260-360 Kcal/Kg, and ideally 290-330 Kcal/Kg. Under normal circumstances, the firing temperature is generally controlled at around 950-1050 degrees Celsius, and the temperature of the waste heat generated will not be too high; The rectangular perforated bricks produced according to the new national standard have relatively smaller ribs due to their higher porosity. The dehydration process of the raw material during water evaporation is called drying shrinkage. Drying shrinkage rate and drying sensitivity are important indicators that should be taken seriously. Usually, a shrinkage rate greater than 6% will cause a large number of cracks, affecting the yield rate. Display the relationship between the drying shrinkage curve and the billet heating curve. Attention should be paid in operation to ensure or coordinate the normal operation of the drying system, including checking whether each fan is running normally and the condition of the incoming and outgoing billet trucks.
In general, only one truck of wet billet blocks is allowed to be loaded into the drying room at a time. The phenomenon of not entering the billet truck for a long time and continuously pushing several trucks in a short period of time should be avoided. When pulling out one truck of dry billet, it is necessary to load one truck of wet billet within a few minutes. Secondly, when loading the billet car into the drying chamber or roasting kiln or pulling out the dried billet or finished product car, the shorter the opening time of the chamber or kiln door, the better, to achieve rapid opening and closing. Again, when loading wet billets, gently pull and slowly push to ensure the stability of the billet stack is not damaged. Before loading into the drying room or roasting kiln, check whether the billet stack is intact and meets the loading standards. When tilting or tilting, or protruding on both sides or top, or when high phenomena are found, they should be repaired one by one. Whether it is manual or mechanical coding, the key points are easy to dry, conducive to baking, and firm and stable. 1. Operate according to the fire path ruler to ensure the smooth flow of the vertical and horizontal fire paths, and prohibit throwing debris such as blocks inside the fire path. 2. Do not protrude too much, and high stacking is strictly prohibited at the top. Ensure vertical stacking and reasonable structure. 3. The upper longitudinal and transverse pulling links should be stacked in place to ensure their sturdy and stable performance. 4. Handle with care and do not violently knock or drop fired brick blocks. 5. During the process of removing raw materials, Chinese medicine must eliminate defective products, and those with high moisture content must be eliminated. 6. If individual blocks of the billet fall off during the grabbing process of the billet machine's mechanical gripper, they should be promptly replenished and made head to head and seam to seam, neat and tidy as before.