During the kiln firing process, the brick and tile green bodies are stacked into fixed, immovable stacks within the kiln channels. The green bodies undergo stages such as the preheating zone, firing zone, heat preservation zone, and cooling zone before being fired into finished bricks and tiles. Once a kiln chamber is filled with stacks, it is sealed tightly. The requirement for sealing is to ensure no air leakage. The method generally involves constructing two walls at the kiln door, leaving an air layer between them to enhance insulation and heat preservation. It is necessary for one wall to be aligned with the kiln interior wall. Some brick factories in the Shanghai area, to save time and materials for sealing, adopt an inner wall construction with a steel plate used for blocking. The gap between the steel door and the kiln frame is sealed with mud, achieving the same purpose. To seal the kiln chamber (across the firing channel), the method of using paste-up paper barriers is typically employed. The requirement is for the paper barrier to be sealed tightly to prevent air leakage. If the paper barrier is not sealed properly, cold air may reverse flow into the preheating zone, lowering the preheating zone temperature and increasing the chimney (or exhaust fan) load, leading to severe rekindling in the firing zone, reduced output, and increased coal consumption. Some brick factories have used glass fiber cloth in place of waste newspapers to seal the kiln chamber, which has also yielded good results. The glass fiber cloth can be used repeatedly over a long period (when opening the barrier, simply use two pincer-shaped steel bars to hold the glass fiber cloth, then rotate the bars to roll up the cloth and remove it from the fire hole), saving costs, and it has excellent sealing performance.

Front-end continuous loading of kiln with坯垛, while the rear-end continuously unloads. Coal is dropped from the kiln top into the kiln for combustion in the firing zone. Cold air enters through the open kiln door at the unloading section, becomes hot air after passing through the cooling and insulation zones, part of which is extracted as heat source for artificial drying rooms, and the rest enters the firing zone for combustion. The smoke generated by combustion transfers its heat to the preheated and drying bodies inside the kiln, then it moves through the exhaust tunnel and branch flue, enters the main flue through the open smoke gate, and is exhausted through the chimney (or exhaust fan). The suction force of the chimney (or exhaust fan) is the driving force for smoke flow, which is also the continuous driving force for the flame to burn bricks and tiles. Since the process of discharging residual moisture from the bodies and the heating process need to be slow, and in order to make full use of the heat in the flue gas, several conical gates (usually 5) are opened in the preheating zone to discharge the flue gas at several locations. The speed at which the "flame" of the circular kiln advances is called the "fire travel speed," typically ranging from 20 to 45 meters per day and night, or even faster. The fire travel speed for firing tiles is lower than that for bricks, usually less than 30 meters per day and night. As the flame moves forward to the next kiln chamber, the conical gate in front of the preheating zone of the previous chamber should be lifted, and the paper barrier burned off, while the conical gate near the firing zone is lowered and sealed shut. This allows each zone to advance to the next kiln chamber. With continuous loading in front and unloading in the back, the firing process in the circular kiln is thus conducted continuously.