Preparation process of low-energy-consumption pottery jar

Abstract

The invention relates to the field of pottery jars, aims to solve the problem that in a high-humidity area, drying of semi-finished products needs to depend on a drying kiln and a preheating zone, so that energy consumption of a kiln is high, and provides a preparation process of a low-energy-consumption pottery jar, which comprises the following steps: drying the products by using waste heat of a firing section and a cooling section of the kiln; the temperature of the kiln firing section ranges from 1100 DEG C to 1200 DEG C; a heat extraction pipeline is arranged above the firing section and the cooling section of the kiln furnace and is provided with a fan; a cold water pipe is arranged below the kiln furnace cooling section, and the water temperature of an outlet of the cold water pipe is 80-90 DEG C; and outlets of the heat extraction pipeline and the cold water pipe are communicated with a kiln furnace drying section. By increasing the temperature of the drying kiln, the moisture content before the pottery jar is put into the kiln can be widened, then the drying stage of the formed wet blank can be promoted to be completed in a high-humidity area, the energy consumption of the drying stage is reduced, the defect of product corner falling in the heating stage of the kiln is avoided, the temperature can be increased at a normal speed in the preheating stage, and the efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the field of pottery jars, and more particularly to a preparation process for low - energy - consumption pottery jars. Background Art

[0002] A pottery jar is a traditional container, usually made of clay, and goes through processes such as shaping, drying, and firing. The preparation of a pottery jar generally requires processes such as material selection, embryo making, trimming and decoration, drying, and firing. Usually, the drying of a wet embryo basically relies on the waste heat of the kiln furnace and the ambient temperature to achieve the drying of semi - finished products. However, in areas with relatively high environmental humidity, such as the Sichuan - Chongqing region, it is difficult to dry the semi - finished products to meet the requirements for loading into the kiln, and it has to rely on the pre - heating zone of the kiln furnace and the drying kiln of the kiln furnace to achieve the purpose of drying semi - finished products, resulting in a delay in the firing time of the kiln furnace, especially an extension of the firing time in the low - temperature section of the kiln furnace, with relatively high energy consumption. Summary of the Invention

[0003] The purpose of the present invention is to provide a preparation process for low - energy - consumption pottery jars, so as to solve the problem that in areas with high humidity, the drying of semi - finished products needs to rely on drying kilns and pre - heating zones, resulting in relatively high energy consumption of the kiln furnace.

[0004] The embodiments of the present invention are realized through the following technical solutions:

[0005] A preparation process for low - energy - consumption pottery jars includes using the waste heat of the firing section and the cooling section of the kiln furnace to dry products; the temperature of the firing section of the kiln furnace is 1100°C - 1200°C; a heat - extraction pipeline is arranged above the firing section and the cooling section of the kiln furnace, and a fan is arranged on the heat - extraction pipeline; a cold - water pipe is arranged below the cooling section of the kiln furnace, and the water temperature at the outlet of the cold - water pipe is 80°C - 90°C; the outlets of the heat - extraction pipeline and the cold - water pipe are both connected to the drying section of the kiln furnace.

[0006] In the prior art, after the wet embryo is formed, it needs to be preliminarily dried before being loaded into the kiln. Usually, the water content of the wet embryo in the preliminary drying stage is reduced from 20% to less than 5%, especially the water content at the relatively thick bottom of the pottery jar reaches less than 5% before it can be dried by the drying kiln and then loaded into the kiln, and can pass through the pre - heating zone without the defect of corner dropping. If the production conditions of the factory are difficult to meet the above - mentioned requirements, it is necessary to extend the heating - up stage of the kiln furnace to achieve the above - mentioned purpose. Therefore, the applicant considered how to increase the lower limit value of this water content of 5% so that the process is more suitable for environments with high humidity. The present invention first increases the drying temperature of the drying kiln of the kiln furnace, which can not only completely dry the parts with high water content at the bottom corners of the pottery jar to 1%, but also, according to experiments, can relax the water content of the pottery jar before loading into the kiln to 7 - 8%. After drying by the drying kiln, the water content before loading into the kiln can also reach less than 1%. In this way, in the 100°C - 400°C section of the pre - heating zone of the kiln furnace, it can be heated up at a normal speed without excessive delay. After the pre - heating section is the firing section and the cooling section.

[0007] To avoid the temperature in the drying kiln from being too high, the present invention comprehensively considers the heat dissipation of the kiln body of the kiln furnace, the flue gas in the kiln, and the recovery and utilization of the waste heat in the cooling section, and uses the aforementioned waste heat for drying the formed wet blanks, which can reduce the humidity of the wet blanks before entering the drying kiln.

[0008] Preferably, the power of the blower is 35 kw - 40 kw, and the inner diameter of the heat extraction pipe is 400 mm - 600 mm.

[0009] By controlling the power and pipe diameter, the drying air volume and wind speed can be regulated. Appropriate air volume and wind speed can effectively carry away the moisture on the surface of the wet blanks, accelerate the evaporation speed, and thus improve the overall drying efficiency. If the wind speed is too low, the humidity in the air is not easily carried away, resulting in a slow drying process; while if the wind speed is too high, it may cause the surface to dry too quickly, forming a hard shell and hindering the diffusion of internal moisture. Reasonable air volume and wind speed help ensure that the product dehydrates evenly during the drying process, avoid quality problems such as cracks and deformations, and controlling the air volume and wind speed is crucial for maintaining the integrity and aesthetics of the product.

[0010] Preferably, after the hot air in the heat extraction pipes in the firing section and the cooling section of the kiln furnace converges, it is connected to the drying section of the kiln furnace; the ratio of the hot air flow rate in the heat extraction pipe in the firing section of the kiln furnace to the hot air flow rate in the heat extraction pipe in the cooling section is 1:(2 - 4).

[0011] The present invention adopts the recovery of multiple types of waste heat, and the entrances of different waste heats in the drying area are different, some are located in the upper part and some are located in the lower part. As a result, there may be differences in the heat received by different parts of the product. If the difference is too large, it is easy to cause defects in the shape of the product. Furthermore, the present invention regulates the air volume of the heat extraction pipes in different sections so that when the temperature after their convergence matches the hot water at the outlet of the cold water pipe, the morphological stability of the product can be ensured.

[0012] Preferably, the drying temperature of the drying kiln of the kiln furnace is 110°C - 150°C; after the pottery jars come out of the drying kiln of the kiln furnace, the water content at the bottom corners of the pottery jars is not higher than 1%.

[0013] Preferably, the water content of the pottery jars before loading into the kiln is 7wt% - 8wt%.

[0014] Since the increase in the temperature of the drying kiln enables the water content at the bottom corners of the pottery jars to be not higher than 1%, the water content of the pottery jars before loading into the kiln can be relaxed to 7% - 8%. This reduces the energy consumption required in the drying stage.

[0015] For most pottery jar enterprises, at present, most of them use the knife-pressure forming and rolling method. Limited by equipment costs, converting to mechanical rolling is very costly, and most enterprises cannot afford it, lacking the universality for industrial implementation. The applicant presents an existing knife-pressure equipment that can be converted to a mechanical rolling method with relatively low cost input. In this way, hard clay can be used for the wet blank, and the water content can be reduced from the source. The density of the wet blank is increased, which also creates convenient conditions for shortening the drying time. The knife in the knife-pressure process can be made of hard wood, and the back of the knife is strengthened with carbon steel. During the rolling process, the iron ring rotates with the mold, the knife does not move, and the gap between the knife and the mold is filled with mud and extruded above the cylinder mouth to complete the rolling process; mechanical rolling is to change the knife to a rotatable circular nylon roller. Since the iron ring also rotates with the mold, the rolling time will be shortened, and the strength of the mud blank will also be increased. Harder clay can also be used, but different from knife-pressure, it cannot roll harder clay.

[0016] Preferably, the raw materials used for the pottery jar contain 8wt%-12wt% of tile granular materials and 5wt%-6wt% of iron; the particle size range of the tile granular materials is 16 mesh - 120 mesh, and among them, the tile granular materials with a particle size of 16 mesh - 80 mesh account for 70wt%-85wt% of the total amount of tile granular materials.

[0017] Solve the problems of blackening, bulging, and insufficient oxidation in the high-temperature section of the firing zone during the rapid firing of pottery jar production. The pottery jar cannot be rapidly fired, which is the second reason for the large gas consumption.

[0018] The clay currently used by the applicant has the characteristics of good plasticity and high drying strength. It contains 5%-6% of iron content and turns into purple sand color after firing. At the high-temperature stage, it also continuously emits other impurities. Such a high iron content and high-temperature volatile impurities also bring problems such as easy insufficient oxidation. Insufficient oxidation will lead to more ferrous oxide, showing black color. High-temperature mixed impurities and insufficient oxidation of mixed iron will cause large bulges in local thickness parts. This requires the kiln to extend the oxidation stage time in the high-temperature section of the preheating zone, and the firing time has to be extended passively, resulting in an increase in gas consumption.

[0019] The applicant introduces the raw material preparation process and adds high-temperature breathable tile granular materials, which can not only recycle waste pottery jars and reduce solid waste emissions, but also reduce the gas consumption problem caused by insufficient oxidation.

[0020] Preferably, the air permeability of the tile granular materials is 15mm / s - 35mm / s.

[0021] Too low air permeability is difficult to effectively solve the problem of insufficient oxidation, but too high air permeability will also lead to a decrease in the strength of the pottery jar, poor water resistance, and poor thermal stability, etc., which will also affect the morphological stability of the pottery jar during the preparation process.

[0022] Preferably, by weight, the tile granular material includes 15 - 20 parts of 16 - mesh granular material, 30 - 50 parts of 40 - mesh granular material, 30 - 40 parts of 60 - mesh granular material, 10 - 15 parts of 100 - mesh granular material, and 10 - 15 parts of 120 - mesh granular material.

[0023] Particles of different particle sizes can be better filled together, reducing voids, thereby improving the density and uniformity of the clay. This helps to maintain a stable shape during the forming process and reduce the risk of cracking or deformation. Large particles can provide structural support and increase the overall strength of the material; while small particles can fill the voids between large particles, forming a more compact structure. The combined use of both can significantly improve the mechanical strength and durability of the finished product. During the firing process, the interaction between large and small particles can help relieve the thermal stress caused by temperature changes. Fine particles contribute to uniform heat transfer, while coarse particles can resist expansion or contraction caused by local high temperatures, jointly enhancing the thermal stability of the product.

[0024] Preferably, the temperature - reducing operation of the pottery jar in the cooling section of the kiln furnace includes: first cooling at a rate of 300℃ / h - 400℃ / h to 600℃ - 700℃, then cooling at a rate of 30℃ / h - 40℃ / h to 450℃ - 500℃, and finally cooling with hot and cold air to 200℃ - 300℃; the temperature difference between the hot and cold air and the pottery jar is 100℃ - 120℃.

[0025] For large - sized pottery jars, they have a large volume, a thick cylinder wall, a small mouth and a large belly, resulting in poor heat dissipation effect in the cooling section of the kiln furnace. To reduce the wind streaks, cold air should not be directly blown onto the product, and only by prolonging the cooling time can the temperature of the cylinder body be slowly reduced by heat dissipation, which leads to a long cooling time and low production efficiency. In this embodiment, after three - stage cooling, on the premise of ensuring the structural strength and morphological integrity of the product after firing, the cooling efficiency is improved and the energy consumption is reduced. The first - stage cooling adopts rapid cooling, hitting red but not black. In this stage, even if the cold - air cooling is extremely fast, no wind - streak phenomenon will occur. Making full use of this stage to cool down can shorten the time. At the same time, rapid cooling can also improve the toughness of the porcelain body and the rapid - cooling and rapid - heating performance of the pottery jar. The second - stage cooling is a slow - cooling stage with a slower cooling rate to avoid rapid - cooling hair cracks. The fracture surface of this kind of crack has luster and is relatively easy to identify. During the above - mentioned cooling process, the rapid - cooling and rapid - heating performance of the product is improved, and thus the limit value of the temperature difference to be controlled in the third - stage cooling is increased. However, when the product is cooled to the same temperature as or close to the hot and cold air, it can be placed in a normal - temperature environment for cooling.

[0026] Preferably, the heat - extraction pipeline in the cooling section is arranged in the first - stage cooling area.

[0027] The first - stage cooling area refers to the area where the product is cooled from the highest temperature to 600℃ - 700℃.

[0028] The present invention has at least the following beneficial effects:

[0029] Through the increase of the temperature in the drying kiln, the water content before the pottery jars are loaded into the kiln can be relaxed, which can promote the completion of the drying stage of the formed wet blanks in a high-humidity area, reduce the energy consumption in the drying stage, avoid solving the defect of product corner chipping through the furnace heating-up stage, allow the preheating section to heat up at a normal speed, and improve the efficiency; recycle a variety of waste heat and use the waste heat for the drying of the formed wet blanks, which can solve the problem that the water content of the product before being loaded into the kiln is difficult to be reduced to the required value, and the utilization of waste heat can also reduce the energy consumption during the drying of the product. Specific Embodiment

[0030] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are clearly and completely described. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention.

[0031] Embodiment 1: A preparation process for low-energy-consumption pottery jars, including drying the products by using the waste heat from the firing section and the cooling section of the kiln; the temperature of the firing section of the kiln is 1100 °C; heat extraction pipes are arranged above the firing section and the cooling section of the kiln, and two heat extraction pipes are installed for each tunnel kiln, and a fan is arranged on the heat extraction pipes; a cold water pipe with a length of 25 meters and an inner diameter of 89 mm is arranged below the cooling section of the kiln, and the water temperature at the outlet of the cold water pipe is 80 °C; the outlets of the heat extraction pipes and the cold water pipe are both connected to the drying section of the kiln; the power of the fan is 35 kw, and the inner diameter of the heat extraction pipe is 400 mm; after the hot air in the heat extraction pipes in the firing section and the cooling section of the kiln converges, it is connected to the drying section of the kiln; the ratio of the hot air flow rate in the heat extraction pipe in the firing section of the kiln to the hot air flow rate in the heat extraction pipe in the cooling section is 1:2. The drying temperature of the drying kiln of the kiln is 110 °C; after the pottery jars come out of the drying kiln of the kiln, the water content at the bottom corners of the pottery jars is not higher than 1%. The water content of the pottery jars before being loaded into the kiln is 7 wt%. The temperature reduction operation of the pottery jars in the cooling section of the kiln includes: first reducing the temperature to 600 °C at a rate of 300 °C / h, then reducing the temperature to 450 °C at a rate of 30 °C / h, and finally using hot and cold air to reduce the temperature to 200 °C; the temperature difference between the hot and cold air and the pottery jars is 100 °C. The heat extraction pipe in the cooling section is arranged in a section of temperature reduction area.

[0032] Example 2: A preparation process of a low - energy - consumption pottery jar, including drying the product by using the waste heat of the firing section and the cooling section of the cellar furnace; the temperature of the firing section of the kiln furnace is 1200 °C; heat - extraction pipes are arranged above the firing section and the cooling section of the cellar furnace, and two heat - extraction pipes are added to each tunnel kiln. A fan is arranged on the heat - extraction pipe; a cold - water pipe with a length of 25 m and an inner diameter of 89 mm is arranged below the cooling section of the cellar furnace, and the water temperature at the outlet of the cold - water pipe is 90 °C; the outlets of the heat - extraction pipe and the cold - water pipe are both connected to the drying section of the cellar furnace; the power of the fan is 40 kw, and the inner diameter of the heat - extraction pipe is 600 mm; after the hot air in the heat - extraction pipes in the firing section and the cooling section of the cellar furnace converges, it is connected to the drying section of the cellar furnace; the ratio of the hot - air flow rate in the heat - extraction pipe in the firing section of the cellar furnace to the hot - air flow rate in the heat - extraction pipe in the cooling section is 1:4. The drying temperature of the drying kiln of the cellar furnace is 150 °C; after the pottery jar comes out of the drying kiln of the cellar furnace, the water content at the bottom corner of the pottery jar is not higher than 1%. The water content of the pottery jar before loading into the kiln is 8 wt%. The temperature - reduction operation of the pottery jar in the cooling section of the cellar furnace includes: first reducing the temperature to 700 °C at a rate of 400 °C / h, then reducing the temperature to 500 °C at a rate of 40 °C / h, and finally using hot and cold air to reduce the temperature to 300 °C; the temperature difference between the hot and cold air and the pottery jar is 120 °C. The heat - extraction pipe in the cooling section is arranged in a section of temperature - reduction area.

[0033] Example 3: A preparation process of a low - energy - consumption pottery jar, including drying the product by using the waste heat of the firing section and the cooling section of the cellar furnace; the temperature of the firing section of the kiln furnace is 1180 °C; heat - extraction pipes are arranged above the firing section and the cooling section of the cellar furnace, and two heat - extraction pipes are added to each tunnel kiln. A fan is arranged on the heat - extraction pipe; a cold - water pipe with a length of 25 m and an inner diameter of 89 mm is arranged below the cooling section of the cellar furnace, and the water temperature at the outlet of the cold - water pipe is 85 °C; the outlets of the heat - extraction pipe and the cold - water pipe are both connected to the drying section of the cellar furnace; the power of the fan is 37 kw, and the inner diameter of the heat - extraction pipe is 500 mm; after the hot air in the heat - extraction pipes in the firing section and the cooling section of the cellar furnace converges, it is connected to the drying section of the cellar furnace; the ratio of the hot - air flow rate in the heat - extraction pipe in the firing section of the cellar furnace to the hot - air flow rate in the heat - extraction pipe in the cooling section is 1:2.8. The drying temperature of the drying kiln of the cellar furnace is 120 °C; after the pottery jar comes out of the drying kiln of the cellar furnace, the water content at the bottom corner of the pottery jar is not higher than 1%. The water content of the pottery jar before loading into the kiln is 7.6 wt%. The temperature - reduction operation of the pottery jar in the cooling section of the cellar furnace includes: first reducing the temperature to 650 °C at a rate of 350 °C / h, then reducing the temperature to 480 °C at a rate of 35 °C / h, and finally using hot and cold air to reduce the temperature to 250 °C; the temperature difference between the hot and cold air and the pottery jar is 110 °C. The heat - extraction pipe in the cooling section is arranged in a section of temperature - reduction area.

[0034] Example 4: A preparation process of a low-energy-consumption pottery jar, which includes drying the product by using the waste heat of the firing section and the cooling section of a cellar furnace; the temperature of the firing section of the cellar furnace is 1180 °C; heat extraction pipes are arranged above the firing section and the cooling section of the cellar furnace, and two heat extraction pipes are installed for each tunnel kiln, and a fan is arranged on the heat extraction pipes; a cold water pipe with a length of 25 m and an inner diameter of 89 mm is arranged below the cooling section of the cellar furnace, and the water temperature at the outlet of the cold water pipe is 85 °C; the outlets of the heat extraction pipes and the cold water pipe are both connected to the drying section of the cellar furnace; the power of the fan is 37 kw, and the inner diameter of the heat extraction pipe is 500 mm; after the hot air in the heat extraction pipes in the firing section and the cooling section of the cellar furnace converges, it is connected to the drying section of the cellar furnace; the ratio of the hot air flow rate in the heat extraction pipe in the firing section of the cellar furnace to the hot air flow rate in the heat extraction pipe in the cooling section is 1:2.8. The drying temperature of the drying kiln of the cellar furnace is 120 °C; after the pottery jar comes out of the drying kiln of the cellar furnace, the moisture content of the bottom corner of the pottery jar is not higher than 1%. The moisture content of the pottery jar before loading into the cellar furnace is 7.6 wt%. The temperature reduction operation of the pottery jar in the cooling section of the cellar furnace includes: first reducing the temperature to 650 °C at a rate of 350 °C / h, then reducing the temperature to 480 °C at a rate of 35 °C / h, and finally using hot and cold air to reduce the temperature to 250 °C; the temperature difference between the hot and cold air and the pottery jar is 110 °C. The heat extraction pipe in the cooling section is arranged in a section of temperature reduction area.

[0035] The raw materials used for the pottery jar contain 8 wt% of tile granular materials and 5 wt% of iron; the particle size range of the tile granular materials is 16 mesh - 120 mesh. The air permeability of the tile granular materials is 15 mm / s. By weight, the tile granular materials include 15 parts of 16-mesh granular materials, 30 parts of 40-mesh granular materials, 30 parts of 60-mesh granular materials, 10 parts of 100-mesh granular materials, and 10 parts of 120-mesh granular materials.

[0036] Example 5: A preparation process of a low - energy - consumption pottery jar includes drying the product by using the waste heat of the firing section and the cooling section of a kiln; the temperature of the firing section of the kiln is 1180 °C; heat - extraction pipes are arranged above the firing section and the cooling section of the kiln, and two heat - extraction pipes are installed for each tunnel kiln. A blower is installed on the heat - extraction pipes; a cold - water pipe with a length of 25 m and an inner diameter of 89 mm is arranged below the cooling section of the kiln, and the water temperature at the outlet of the cold - water pipe is 85 °C; the outlets of the heat - extraction pipes and the cold - water pipe are both connected to the drying section of the kiln; the power of the blower is 37 kw, and the inner diameter of the heat - extraction pipe is 500 mm; after the hot air in the heat - extraction pipes in the firing section and the cooling section of the kiln converges, it is connected to the drying section of the kiln; the ratio of the hot - air flow rate in the heat - extraction pipe in the firing section of the kiln to the hot - air flow rate in the heat - extraction pipe in the cooling section is 1:2.8. The drying temperature of the drying kiln of the pottery jar is 120 °C; after the pottery jar comes out of the drying kiln of the kiln, the moisture content at the bottom corner of the pottery jar is not higher than 1%. The moisture content of the pottery jar before loading into the kiln is 7.6 wt%. The temperature - reduction operation of the pottery jar in the cooling section of the kiln includes: first, cooling down to 650 °C at a rate of 350 °C / h, then cooling down to 480 °C at a rate of 35 °C / h, and finally using hot and cold air to cool down to 250 °C; the temperature difference between the hot and cold air and the pottery jar is 110 °C. The heat - extraction pipes in the cooling section are arranged in a section of temperature - reduction area.

[0037] The raw materials used for the pottery jar contain 12 wt% of tile granular materials and 6 wt% of iron; the particle - size range of the tile granular materials is 16 mesh - 120 mesh. The air permeability of the tile granular materials is 35 mm / s. By weight, the tile granular materials include 20 parts of 16 - mesh granular materials, 50 parts of 40 - mesh granular materials, 40 parts of 60 - mesh granular materials, 10 parts of 100 - mesh granular materials, and 10 parts of 120 - mesh granular materials.

[0038] Example 6: A preparation process of a low-energy-consumption pottery jar, including drying the product by using the waste heat of the firing section and the cooling section of the cellar furnace; the temperature of the firing section of the kiln furnace is 1180 °C; heat extraction pipes are arranged above the firing section and the cooling section of the cellar furnace, and two heat extraction pipes are installed on each tunnel kiln, and a fan is arranged on the heat extraction pipes; a cold water pipe with a length of 25 m and an inner diameter of 89 mm is arranged below the cooling section of the cellar furnace, and the water temperature at the outlet of the cold water pipe is 85 °C; the outlets of the heat extraction pipes and the cold water pipe are both connected to the drying section of the cellar furnace; the power of the fan is 37 kw, and the inner diameter of the heat extraction pipe is 500 mm; after the hot air in the heat extraction pipes in the firing section and the cooling section of the cellar furnace converges, it is connected to the drying section of the cellar furnace; the ratio of the hot air flow rate in the heat extraction pipe in the firing section of the cellar furnace to the hot air flow rate in the heat extraction pipe in the cooling section is 1:2.8. The drying temperature of the drying kiln of the cellar furnace is 120 °C; after the pottery jar comes out of the drying kiln of the cellar furnace, the water content at the bottom corner of the pottery jar is not higher than 1%. The water content of the pottery jar before loading into the kiln is 7.6 wt%. The temperature reduction operation of the pottery jar in the cooling section of the cellar furnace includes: first reducing the temperature to 650 °C at a rate of 350 °C / h, then reducing the temperature to 480 °C at a rate of 35 °C / h, and finally using hot and cold air to reduce the temperature to 250 °C; the temperature difference between the hot and cold air and the pottery jar is 110 °C. The heat extraction pipe in the cooling section is arranged in a section of temperature reduction area.

[0039] The raw materials used in the pottery jar contain 10 wt% of tile granular materials and 5.5 wt% of iron; the particle size range of the tile granular materials is 16 mesh - 120 mesh. The air permeability of the tile granular materials is 26 mm / s. By weight, the tile granular materials include 18 parts of 16-mesh granular materials, 40 parts of 40-mesh granular materials, 35 parts of 60-mesh granular materials, 12 parts of 100-mesh granular materials, and 12 parts of 120-mesh granular materials.

[0040] Comparative Example 1: A preparation process of a low - energy - consumption pottery jar, including using the waste heat of the firing section and the cooling section of the cellar furnace to dry the product; the temperature of the firing section of the kiln furnace is 1180 °C; heat - extraction pipes are arranged above the firing section and the cooling section of the cellar furnace, and two heat - extraction pipes are installed on each tunnel kiln, and a fan is arranged on the heat - extraction pipe; a cold - water pipe with a length of 25 m and an inner diameter of 89 mm is arranged below the cooling section of the cellar furnace, and the water temperature at the outlet of the cold - water pipe is 85 °C; the outlets of the heat - extraction pipe and the cold - water pipe are both connected to the drying section of the cellar furnace; the power of the fan is 37 kw, and the inner diameter of the heat - extraction pipe is 500 mm; after the hot air in the heat - extraction pipes in the firing section and the cooling section of the cellar furnace converges, it is connected to the drying section of the cellar furnace; the ratio of the hot - air flow rate in the heat - extraction pipe in the firing section of the cellar furnace to the hot - air flow rate in the heat - extraction pipe in the cooling section is 1:5. The drying temperature of the drying kiln of the cellar furnace is 120 °C; after the pottery jar comes out of the drying kiln of the cellar furnace, the moisture content at the bottom corner of the pottery jar is not higher than 1%. The moisture content of the pottery jar before loading into the kiln is 7.6 wt%. The temperature - reduction operation of the pottery jar in the cooling section of the cellar furnace includes: first reducing the temperature to 650 °C at a rate of 350 °C / h, then reducing the temperature to 480 °C at a rate of 35 °C / h, and finally using hot and cold air to reduce the temperature to 250 °C; the temperature difference between the hot and cold air and the pottery jar is 110 °C. The heat - extraction pipe in the cooling section is arranged in a section of temperature - reduction area.

[0041] The raw materials used for the pottery jar contain 10 wt% of tile granular materials and 5.5 wt% of iron; the particle size range of the tile granular materials is 16 mesh - 120 mesh. The air permeability of the tile granular materials is 26 mm / s. By weight, the tile granular materials include 18 parts of 16 - mesh granular materials, 40 parts of 40 - mesh granular materials, 35 parts of 60 - mesh granular materials, 12 parts of 100 - mesh granular materials, and 12 parts of 120 - mesh granular materials.

[0042] Comparative Example 2: A preparation process of a low-energy-consumption pottery jar, including drying the product by using the waste heat of the firing section and the cooling section of the cellar furnace; the temperature of the firing section of the kiln furnace is 1180 °C; heat extraction pipes are arranged above the firing section and the cooling section of the cellar furnace, and two heat extraction pipes are added to each tunnel kiln, and a fan is arranged on the heat extraction pipes; a cold water pipe with a length of 25 meters and an inner diameter of 89 mm is arranged below the cooling section of the cellar furnace, and the water temperature at the outlet of the cold water pipe is 85 °C; the outlets of the heat extraction pipes and the cold water pipe are both connected to the drying section of the cellar furnace; the power of the fan is 37 kw, and the inner diameter of the heat extraction pipe is 500 mm; after the hot air in the heat extraction pipes in the firing section and the cooling section of the cellar furnace converges, it is connected to the drying section of the cellar furnace; the ratio of the hot air flow rate in the heat extraction pipe in the firing section of the cellar furnace to the hot air flow rate in the heat extraction pipe in the cooling section is 1:2.8. The drying temperature of the drying kiln of the cellar furnace is 120 °C; after the pottery jar comes out of the drying kiln of the cellar furnace, the moisture content at the bottom corner of the pottery jar is not higher than 1%. The moisture content of the pottery jar before being loaded into the kiln is 7.6 wt%. The temperature reduction operation of the pottery jar in the cooling section of the cellar furnace includes: first reducing the temperature to 650 °C at a rate of 350 °C / h, then reducing the temperature to 480 °C at a rate of 35 °C / h, and finally using hot and cold air to reduce the temperature to 250 °C; the temperature difference between the hot and cold air and the pottery jar is 110 °C. The heat extraction pipe in the cooling section is arranged in a section of temperature reduction area.

[0043] The raw material used for the pottery jar contains 5.5 wt% of iron.

[0044] Comparative Example 3: A preparation process of a low-energy-consumption pottery jar, including drying the product by using the waste heat of the firing section and the cooling section of the cellar furnace; the temperature of the firing section of the kiln furnace is 1180 °C; heat extraction pipes are arranged above the firing section and the cooling section of the cellar furnace, and two heat extraction pipes are added to each tunnel kiln, and a fan is arranged on the heat extraction pipes; a cold water pipe with a length of 25 meters and an inner diameter of 89 mm is arranged below the cooling section of the cellar furnace, and the water temperature at the outlet of the cold water pipe is 85 °C; the outlets of the heat extraction pipes and the cold water pipe are both connected to the drying section of the cellar furnace; the power of the fan is 37 kw, and the inner diameter of the heat extraction pipe is 500 mm; after the hot air in the heat extraction pipes in the firing section and the cooling section of the cellar furnace converges, it is connected to the drying section of the cellar furnace; the ratio of the hot air flow rate in the heat extraction pipe in the firing section of the cellar furnace to the hot air flow rate in the heat extraction pipe in the cooling section is 1:2.8. The drying temperature of the drying kiln of the cellar furnace is 120 °C; after the pottery jar comes out of the drying kiln of the cellar furnace, the moisture content at the bottom corner of the pottery jar is not higher than 1%. The moisture content of the pottery jar before being loaded into the kiln is 7.6 wt%. The temperature reduction operation of the pottery jar in the cooling section of the cellar furnace includes: first reducing the temperature to 650 °C at a rate of 350 °C / h, then reducing the temperature to 480 °C at a rate of 35 °C / h, and finally using hot and cold air to reduce the temperature to 250 °C; the temperature difference between the hot and cold air and the pottery jar is 110 °C. The heat extraction pipe in the cooling section is arranged in a section of temperature reduction area.

[0045] The raw materials used for the pottery jars contain 10 wt% of tile granular materials and 5.5 wt% of iron; the particle size range of the tile granular materials is 16 mesh - 120 mesh. The air permeability of the tile granular materials is 40 mm / s. By weight, the tile granular materials include 18 parts of 16-mesh granular materials, 40 parts of 40-mesh granular materials, 35 parts of 60-mesh granular materials, 12 parts of 100-mesh granular materials, and 12 parts of 120-mesh granular materials.

[0046] Experiment

[0047] The clay used is Rongxian clay, and its chemical composition includes 76.2% of silicon dioxide, 19.13% of aluminum oxide, 5.5% of iron oxide in the clay, 2.25% of potassium oxide, 0.114% of sodium oxide, and 0.81 of magnesium oxide.

[0048] Experiment 1: Pottery jars were prepared according to the preparation processes provided in Examples 1 - 6 and Comparative Examples 1 - 3. In Examples 1 - 3, Rongxian clay was directly used, and the height of the jars was 2.5 m. Then, the appearance quality of the pottery jars was detected. Among them, the pottery jars prepared according to the preparation processes of Examples 1 - 3 had no cracks, no bubbles, and no deformation. Certain shape defects occurred in Comparative Examples 1 - 3. The yield is shown in Table 1.

[0049] Table 1

[0050] Example 1 Example 2 Example 3 Example 4 Example 5 Yield 94.7％ 95.2％ 96.4％ 95.9％ 98.4％ Example 6 Comparative Example 1 Comparative Example 2 Comparative Example 3 Yield 99.3％ 87.9％ 71.6％ 91.7％

[0051] From the test results of Examples 1 - 6, it can be seen that the pottery jars prepared by using the preparation processes provided in Examples 1 - 6 have a high yield.

[0052] From the comparison between Comparative Examples 1 - 3 and Example 6, it can be seen that the ratio of the hot air flow rate of the heat extraction pipeline in the firing section of the cellar furnace to the hot air flow rate of the heat extraction pipeline in the cooling section, the clay composition, and the air permeability of the tile granular materials all affect the appearance quality of the product.

[0053] Experiment 2: Pottery jars were prepared according to the pottery jar preparation processes provided in Examples 1 - 6 and Comparative Examples 1 - 3, and then the performance of the pottery jars was detected. The average value was taken after each group was tested 5 times. The test results are shown in Table 2.

[0054] Table 2

[0055]

[0056]

[0057] From the test results of Examples 1 - 6, it can be seen that the pottery jars prepared by using the preparation processes provided in Examples 1 - 6 have good strength performance.

[0058] From the comparison between Comparative Examples 1-3 and Example 6, it can be seen that the hot air flow rate ratio of the heat extraction pipeline in the firing section of the kiln to that in the cooling section, the clay composition, and the air permeability of the tile granular material all significantly affect the mechanical properties of the product.

[0059] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A preparation process of a low-energy-consumption pottery jar, characterized in that, It includes drying products by using the waste heat of the firing section and the cooling section of the kiln; the temperature of the firing section of the kiln is 1100°C - 1200°C; a heat extraction pipe is arranged above the firing section and the cooling section of the kiln, and a fan is arranged on the heat extraction pipe; a cold water pipe is arranged below the cooling section of the kiln, and the water temperature at the outlet of the cold water pipe is 80°C - 90°C; the outlet of both the heat extraction pipe and the cold water pipe is connected to the drying section of the kiln.

2. The preparation process according to claim 1, wherein The power of the fan is 35kw - 40kw, and the inner diameter of the heat extraction pipe is 400mm - 600mm.

3. The preparation process according to claim 2, characterized in that, After the hot air in the heat extraction pipes in the firing section and the cooling section of the kiln converges, it is connected to the drying section of the kiln; the ratio of the hot air flow rate in the heat extraction pipe in the firing section of the kiln to the hot air flow rate in the heat extraction pipe in the cooling section is 1:(2 - 4).

4. The preparation process according to claim 1, characterized in that, The drying temperature of the drying kiln of the kiln is 110°C - 150°C; after the pottery jars come out of the drying kiln of the kiln, the moisture content at the bottom corners of the pottery jars is not higher than 1%.

5. The preparation process according to claim 4, characterized in that, The moisture content of the pottery jars before being loaded into the kiln is 7wt% - 8wt%.

6. The preparation process according to any one of claims 1-5, characterized in that, The raw materials used for the pottery jars contain 8wt% - 12wt% of tile granular materials and 5wt% - 6wt% of iron; the particle size range of the tile granular materials is 16 mesh - 120 mesh, and among them, the tile granular materials with a particle size of 16 mesh - 80 mesh account for 70wt% - 85wt% of the total amount of tile granular materials.

7. The preparation process according to claim 6, characterized in that, The air permeability of the tile granular materials is 15 mm / s - 35mm / s.

8. The preparation process according to claim 6, characterized in that, By weight, the tile granular materials include 15 - 20 parts of 16 - mesh granular materials, 30 - 50 parts of 40 - mesh granular materials, 30 - 40 parts of 60 - mesh granular materials, 10 - 15 parts of 100 - mesh granular materials, and 10 - 15 parts of 120 - mesh granular materials.

9. The preparation process according to claim 6, characterized in that, The temperature - reduction operation of the pottery jars in the cooling section of the kiln includes: first reducing the temperature at a rate of 300°C / h - 400°C / h to 600°C - 700°C, then reducing the temperature at a rate of 30°C / h - 40°C / h to 450°C - 500°C, and finally using hot and cold air to reduce the temperature to 200°C - 300°C; the temperature difference between the hot and cold air and the pottery jars is 100°C - 120°C.

10. The preparation process according to claim 9, characterized in that, The heat extraction pipe in the cooling section is arranged in a first - stage temperature - reduction area.

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