Wild farming: I was hugged by the cold patriarch

Chapter 83 083. Brick-firing process
The technical requirements for the entire kiln installation must follow the kiln fire combustion cycle rules, obey the technical rules of kiln firing, and fully grasp the principle of "two tights and three looses", that is, tight at the fire stop, tight at the middle and loose at the bottom, loose at the kiln wall, and loose at the top. , to meet the needs of making full use of the fire intensity and uniform fire control, and effectively prevent the bricks and tiles in the kiln from being damaged by local deformation, scorch flow or inclusion due to uneven fire intensity.

When the whole kiln was gradually filled with bricks, Ye Sang, Gancang and several other tribesmen who joined behind them were loading and retreating from the "Second Kiln Gate", sealing it with stones and sealing it with yellow mud.

The next step is to load charcoal into the "Fire Court".

Below the "Fire Court" is the ash leakage layer, also called the "Grey Court". A three-sided "Liao" made of pig iron is set up between the two "courts".

Ye Sang entered the "Fire Garden" and arranged the stubbles in layers along the charcoal pattern. He also gradually exited. He left a "firewood nest" of appropriate size at the entrance and put in flammable hay, and then put some firewood that could easily catch fire. Firewood is commonly known as "velvet firewood" and "hard firewood".

After installing the charcoal, bricks can be laid to seal the "big kiln door".

The "big kiln door" is the "working surface" or "operating table" for the entire brick kiln firing.

Generally, it is blocked from bottom to top according to the second and fourth walls, leaving two layers of "whistle eyes", or "fire eyes", at an appropriate distance apart, with the lower layer being larger.

It can be filled with two bricks horizontally and vertically. The upper layer is reduced by about half, and can be filled with one brick horizontally and vertically. Both are used for stirring up the fire with an iron "stove cone" or "fire hook".

The upper part was built with one or two walls, and the bricks were laid flush with the side facing the fire court. A "fire doorway" about five feet square was left in the middle of the bottom, and a "fire door stop" was placed on a protruding narrow platform below.

When burning the kiln, add charcoal from the "fire door" to the "fire court" to continue the fire.

There is also a "wind eye" about the size of a fist on the "fire door", which is also used as a "lookout hole". It is used to help control and observe the fire intensity when the kiln is fired. The fire door is basically closed when the fire intensity is normal or slightly small, and the air intake is opened when the fire intensity is large. to reduce the intensity of the fire.

Finally, the entire "working surface" was reinforced with yellow mud.

The book says that the processes of loading charcoal and erecting the "big kiln door" are collectively called "finishing" or "building the kiln". At this point, everything is ready, just waiting to burn the firewood and light the kiln.

Ignition is also exquisite.

Usually in the afternoon or evening, sometimes at noon, as long as it is not windy, no matter it is cloudy or sunny, the fire can be lit at any time during the day.

In case of windy weather, you must wait until the evening to light the fire.

The charcoal fire in the kiln can basically be ignited overnight, and charcoal needs to be added early the next morning.

Sooner or later, the time of adding fire depends on the weather. On windy days, charcoal fires burn faster, so you should add fire in advance.

Generally, counting from the time of ignition, until the evening of the same day or the next morning, it is allowed to burn by itself. This process is called "smoke kiln".

The length of the "smoke kiln" time is determined by the dryness and wetness of the bricks. Appropriate amount of charcoal will be added as appropriate in the middle, and all will be burned with a slow fire.

At this stage, the "flue" embedded in the kiln wall is covered with stone, and the smoke is mainly exhausted around the kiln wall.

At this stage, you can take a short rest or have a good sleep to reduce the fatigue from the days of installing the kiln, so that you can have enough energy to start the next four or five days of staying up day and night to watch the fire.

Kiln burning is more demanding, and success or failure depends on it. Ye Sang can't sleep well at night because he is afraid of failure.

Seeing her nervousness, the tribe members also became nervous, especially Yucang, who went to bed very late every night. The time of "smoking the kiln" can last up to one day, that is, in the evening of the next day, the fire "shaking the stove" will begin to increase the firepower, officially entering the important stage of firing the kiln.

The high-fire kiln firing is divided into three steps: "upper fire, medium fire and lower fire", also known as "front fire, boiling fire and back fire". If necessary, "chasing fire" must be used to ensure that the entire kiln is fired perfectly.

"Firing up" must keep the charcoal fire rising in a balanced cycle. At this stage, the "flue" embedded in the kiln wall does not open.

Generally, the "fire attack" is carried out for a day and night or a little longer, and the kiln wall is observed on the top of the kiln to see whether the initial black coal gradually turns white.

Gradually lay down bricks around the whitened areas and cover the kiln wall so that the fire can converge on the parts that have not yet turned white due to lack of fire.

At the same time, a tile roof brick must be placed longitudinally every five or six bricks along the kiln wall, leaving an appropriate gap as an outlet for fireworks emissions. The opening and closing degree can be controlled at any time to control the intensity of the fire.

When the kiln wall is all white and the above treatment process is completed, go to the bottom of the kiln to observe the fire intensity and brick fire color in the "fire stop" through the "fire door" and "lookout hole". If there is a uniform red state, it means that the kiln fire has Returning from the top to the center, the "heating" is successfully completed and the "medium fire" stage is entered.

When burning "medium fire", you still need to add charcoal on time to maintain sufficient fire power. The "flue" on the kiln wall is still closed. The fire intensity and temperature in the entire kiln must be balanced and the circulation of all parts must be smooth.

It is not unreasonable to call "medium fire" as "boiling fire" as mentioned above. This stage generally lasts for two to three days and nights, and the specific situation also depends on the color of the fire.

It is appropriate for the fire to remain red and unchanged, and it is moderate for the fire to neither darken nor turn white.

Dark color indicates small fire, white color indicates large fire, both must be controlled in time.

The book says that when the fire is "medium fire", if the fire is too strong, it is easy to cause coking, burning and even "fire blocking" deformation;

If the fire is too small, it will easily lead to problems such as incomplete ripening, poor strength and impure color. Improper handling will affect the color and quality of the kiln's bricks and tiles.

When the fire temperature and color in the center of the "blocking fire" and up and down are consistent and uniform and translucent, the "medium fire" is completed. At this time, the entire kiln bricks are basically mature, but they still need to be burned through the "lower fire".

At this time, except for the exit of the top brick, which is made up of two bricks lying in a figure-eight shape and forming a triangular fireworks channel with the kiln wall, all other parts of the kiln roof are paved with bricks close to the kiln wall and covered with soil.

At the same time, except for the "fire entrance" and "lookout hole" on the "working surface" at the bottom of the kiln, all other "whistle holes" are blocked and sealed with yellow mud.

During the "hot" and "medium fire" stages, a large amount of charcoal ash is produced due to continuous addition of fire. When it accumulates to a certain extent, it needs to be cleaned up in time to maintain normal ventilation of the "fire garden".

However, when the "fire" came, there was basically no need to clean up. Instead, more than half of the entrance to the "Grey Court" was blocked with stones.

During the "fire down" stage, the kiln wall "flues" are all opened to promote ventilation and smoke exhaust.

At this stage, you should pay close attention to the fire color of the "Laojun bricks" reserved on the "fire blocking" surface and the "fire blocking hole". You can also go to the top of the kiln and observe vertically downward from the unblocked fireworks channel at the kiln wall. The fire color of the bricks and tiles as far as the eye can see is repeatedly compared to see if they are as uniform and translucent as the fire color of the "fire blocking" bricks.

When the fire color of the "Laojun bricks" and the "blocking fire" bricks are the same from the "fire gate" and show a red, tender and bright color, it means that the entire kiln bricks have been completely fired.

At the same time, you can also take some firewood and test burn it at the "flue" opening on the top of the kiln. If the flames continue to rise, it means that the subsequent burning is successful.

(End of this chapter)