In early May this year, the Xinruncheng 600×600×9mm, double-zero water absorption permeable tile production line built by Keda set a record of the lowest natural gas energy consumption of 1.13m³/㎡ after operating stably for more than a month. At the same time, Electricity consumption is also 20% lower than that of the old kiln;
In 2020, Zhongpeng Thermal Energy renovated a 300×600×7.5mm medium plate production line for Fujian Haoshan Enterprise, achieving natural gas energy consumption of less than 1m³/㎡;
As early as 2019, the comprehensive natural gas energy consumption of the Qingyuan Mona Lisa 800×800mm double-zero water absorption full glazing production line constructed by Delitai was maintained at 1.55-1.6Nm³/㎡;
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▲ Xinruncheng Third Company (Huiqiang Ceramics) infiltrated brick wide-body kiln built by Keda.
In recent years, the problem of overcapacity in ceramic tiles has become increasingly prominent. Product homogeneity due to highly mature product technology has triggered fierce price competition. However, the overall cost of ceramic tile production has continued to rise, which has greatly squeezed the profits of ceramic companies. space. Therefore, on the premise of ensuring product quality, reducing production costs through energy conservation and consumption reduction has become the goal pursued by more and more ceramic companies.
At the same time, under the policy requirements of "carbon peaking and carbon neutrality", the total amount and intensity of energy consumption are strictly controlled, which also requires ceramic companies to reduce energy consumption, and even many new construction and renovation projects this year The application was suspended due to failure in the ability assessment.
Fuel costs generally rose by more than 10%
Energy consumption attracts attention of ceramic enterprises
Jing Haishan, deputy general manager of Foshan Delitai Technology Co., Ltd., made an calculation: when ceramic factories across the country generally burned coal, the coal price was about more than 600 yuan/ton, and 1 ton of powder would produce approximately 33 square meters of ceramic tiles. For the production of the most conventional 800×800mm ceramic tiles, the spray tower requires 55 kilograms of coal, which is about 1.7 kilograms of coal/m2. The wide-body kiln consumes about 3.3 kilograms of coal/m2. The total coal-fired cost is less than 3 Yuan/㎡, which accounts for a relatively small proportion of the production cost of ceramic tiles. The cost difference caused by whether it is energy-saving is not big, and it is not easy to quantify, so it is rarely cited.Enterprises must pay enough attention to it.
Many industry insiders believe that the turning point that caused ceramic companies to pay attention to energy consumption was the popularization of natural gas. Since Jinjiang, Fujian Province became the first production area to fully implement "coal to gas" in 2014, since 2016, Shandong, Sichuan , Liaoning Faku, Hebei Gaoyi, Guangdong, etc. have successively implemented natural gas transformation. Now the number of ceramic enterprises using natural gas in the country has exceeded half. Compared with coal, natural gas has a stable calorific value, is easy to manage and count, and can better quantify the proportion of energy consumption in production costs.
“For the same 800×800mm tiles, after the narrow-body kiln is switched to natural gas, it will require about 2Nm³ natural gas/㎡. If the natural gas price is calculated at 2.5 yuan/m³, even if the spray tower still burns coal, the overall cost will increase by about 10%. ." Jing Haishan further calculated.
▲ The rising costs caused by coal-to-gas conversion have forced a large number of ceramic companies to achieve energy conservation and consumption reduction through technological transformation.
Not only gas companies, but also coal-fired companies are not immune. "The price of coal was about 800 yuan/ton in October last year, and it is as high as 1,200 yuan this year. This rising cost alone can cause the comprehensive cost of ceramic companies to increase by 12 to 13%. Few companies can afford it, so We must start from ourselves to reduce costs." He Weidong, assistant general manager of Foshan Keda Mechanical and Electrical Co., Ltd. believes that cost pressure has prompted ceramic companies to start paying attention to energy conservation and consumption reduction to reduce production costs.
In addition, the National Development and Reform Commission in the "Guiding Opinions on Strengthening the Prevention and Control of Ecological Environment Sources of High Energy-Consumption and High-Emission Construction Projects" clarified that "two high" projects are temporarily classified as coal power, petrochemicals, chemicals, steel, non-ferrous metal smelting, According to the statistics of six industry categories including building materials, as an important part of the large building materials industry, the ceramic industry has also officially entered the "Two Highs" and has become one of the key industries that controls both total energy consumption and intensity.
In fact, under the policy background of "carbon peaking and carbon neutrality", many places have introduced management regulations on energy consumption in the ceramic industry since this year, and a large number of new construction and renovation projects have been postponed due to energy assessment. For the ceramic industry, it will set off a new revolution in energy conservation and emission reduction.
Equipment replacement, technological innovation
Create energy conservationNew peak in consumption reduction
In the early days of natural gas transformation, most companies only completed energy replacement through pipeline renovation and replacement of spray guns. However, the excessive energy consumption made it unbearable for the companies, forcing the industry to conduct in-depth energy-saving research, in which the innovation and replacement of equipment began. It has played a big role.
“Many kilns in some large production areas have been used for more than ten years. In terms of production capacity, product matching, and insulation effects, they are no longer suitable for market development, prompting companies to iterate production equipment and production processes.” He Weidong Introduction: Since 2019, starting from Guangdong and Shandong and then to Jiangxi, Sichuan and other production areas, equipment replacement has been very common. New equipment and new technologies have focused on energy conservation as a key research and development direction.
“We also burn natural gas to produce 600×600mm and 800×800mm glazed tiles of the same specifications. Calculated based on the energy consumption per kilogram of porcelain, our country generally requires 500 kcal/kg, while India generally only requires 400 kcal. /kg, we are still 25% higher. "Jing Haishan analyzed that the high unit energy consumption of domestic ceramic tile kilns is mainly related to the longer kiln design and larger output. Under the domestic high-temperature and fast-firing firing system, preheating The zone temperature is set too high, resulting in high exhaust gas temperature and a lot of waste of external heat. In addition, the long kiln has a large positive pressure and an increased heat dissipation area, which greatly results in heat waste and no energy saving.
Jing Haishan pointed out that to reduce energy consumption, first of all, the flue gas emissions must be reduced, the flue gas temperature must be lowered, and the other is the organized combustion of fuel. Therefore, both kiln companies including Keda and Delitai have launched high-precision energy-saving burners, and have made combustion more reasonable and efficient through air-fuel proportional combustion systems and combustion-supporting air heating systems.
Recovering heat through an efficient waste heat recovery and utilization system is a standard feature of today's kilns. During the production process of ceramic tiles, the temperature of the product rises from normal temperature to 1230°C, and then is cooled down to about 100°C before leaving the kiln. The heat emitted by cooling has great room for recycling.
In addition, Jing Haishan believes that in the thermal balance of the kiln, the heat taken away by the exhaust smoke accounts for about 20 to 30% of the total energy consumption. If it is directly discharged to the desulfurization tower, it will not only waste but also increase the cost of terminal treatment. Now through the flue gas After heat exchange in the heat exchanger, 50-60% of the heat of the flue gas can be recovered, and then transported to the dryer for heating and utilization, basically achieving a high ratio of recovery of kiln flue gas and waste heat, and basically achieving zero energy consumption in drying.
▲ Delitai total waste heat recovery system.
The upgrade of new thermal insulation materials for kilns such as nano powder and nano insulation panels/bricks has also greatly reduced heat loss. He Weidong introduced that around 2015, the temperature of many kilns and kiln roofs reached more than 100 degrees Celsius. Now through design and materials, it can be controlled to more than 70 degrees Celsius; the temperature outside the kiln wall no longer exceeds 60 degrees Celsius, which fully shows that the insulation effect is more effective. Well, it has a great effect on energy saving.
In addition to energy saving, in terms of power saving, Jing Haishan also introduced that the reasonable design of the air duct reduces the gas flow rate and reduces the resistance, allowing the low-frequency operation of the fan to greatly save power consumption.
At the same time, in the post-kiln link, PC control of the entire post-kiln line is realized, which also achieves a nearly 20% reduction in power consumption. It is understood that if the equipment continues to operate in each link after the kiln, the comprehensive operating efficiency of the polishing link is about 80%, the packaging line is about 60%, and the brick storage line is less than 50%. Keda is changing this situation through post-kiln integration innovation. Improving the comprehensive operation efficiency of the equipment through total control and using PC to manage and control the back-end equipment not only improves the stability and intelligence of the equipment, but also greatly saves the number of employees and power consumption.
▲ The whole line after the kiln.
Product thinning, formula optimization
Low temperature and fast burning to achieve low energy consumption
In addition to precise management and the application of new technologies developed by upstream equipment companies, ceramic companies themselves have also achieved significant results in energy conservation and consumption reduction through product innovation.
"India has lower energy consumption than us. One of the reasons is that their products are relatively thin. We generally use 10.2mm conventional 800×800mm glazed tiles. Their thickness is about 9.8mm, and the product formula and process are also different. , can burn at low temperature and quickly." Jing Haishan believes that thinning ceramic tiles must be the future development direction, which not only saves energy, but also saves resources.
▲ Medium plate is an innovative product for ceramic tile thinning. The picture shows the Sichuan Lihong medium plate production line built by Delitai.
Today, the development of medium and thin plates also confirms this statement. He Weidong introduced that a new thin plate line built by Keda in Fujian has a minimum natural gas energy consumption of 1.12m³/㎡. According to "Ceramic Information", the energy consumption of the 7-8mm medium plate, which is gradually becoming a mainstream product in the ceramic industry, can be reduced to less than 1.2m³/㎡.
Cheng Zhaohua, general manager of Foshan Jiayun Kiln Technology Co., Ltd., who specializes in kiln technical transformation, has experienced a large number of technical transformation projects of ceramic companies and found that ceramic companies are also reducing product costs, such as reducing more ultra-white high-temperature The use of raw materials enables low-temperature and fast burning to achieve the purpose of reducing energy consumption.
Energy consumption hits new lows
A new kiln can be saved in three years
How different is the comprehensive energy saving and consumption reduction effect compared with the energy consumption of traditional production lines? How much effect can it bring to ceramic companies?
Taking natural gas transformation as an example, it is generally believed that to produce 800×800×(10.5~11) mm single zero water absorption glazed tiles, depending on the length and width of the kiln, the energy consumption after the old kiln is converted to natural gas is basically 1.8 ~2m³/㎡.
Cheng Zhaohua introduced that the ceramic companies that were the first to switch to natural gas had no production experience and often had energy consumption as high as 2.6 to 2.8m³/㎡ when producing conventional 800×800mm ceramic tiles. However, through energy-saving transformation, the minimum can now be reduced. to 1.6m³/㎡.
“We built a new mixed-fired 800×800mm and 600×1200mm glazed tile production line in Jiangxi last year, with a daily output of 47,000 square meters, using natural gas. According to past experience, such a large-capacity production line generally requires the use of water gas. 3.5~3.8m³/㎡, which is about 1.9m³/㎡ when converted to natural gas, but we actually achieved 1.65-1.7m³/㎡.” He Weidong pointed out that through equipment upgrades, the energy-saving effect has also been achieved in large-capacity production lines. .
▲ The glazed tile production line built by Keda with a daily output of 47,000㎡ has an energy consumption of up to 1.65-1.7m³/㎡ .
Although for most production areas and enterprises, sufficient energy saving and consumption reduction cannot completely offset the rising costs after switching to natural gas, compared with the direct use of natural gas in old kilns, the contrasting effect is very obvious. Take the brand-new 800×800mm glazed tile production line with double zero water absorption of a ceramics company in Qingyuan built by Delitai as an example. After switching to natural gas, the natural gas energy consumption of the company's old line kiln is basically about 1.9m³/㎡. The newly built The kiln energy consumption target is 1.6m³/㎡, but it actually achieved 1.55m³/㎡.
“According to the natural gas price at that time of 2.5 yuan/㎡, the energy consumption cost would be nearly 1 yuan/㎡. The daily output was about 12,000 square meters, which would save about 3.6 million yuan a year. Through energy consumption savings "The investment in the production line can be recovered in more than 3 years." Jing Haishan believes that the energy consumption of conventional 800×800mm glazed tiles with double zero water absorption was reduced from 2m³/㎡ to less than 1.6m³/㎡, which was of epoch-making significance. of.
In the view of many industry insiders, under the background of "carbon peaking and carbon neutrality", energy saving and consumption reduction will be an important issue for the ceramic industry, which is listed as a "two high" project, for a long time. The current better emission reduction solutions, whether they are newly built or technologically renovated production lines, benefit from the advancement of energy-saving technology and refined management. While improving product quality, they can achieve the superimposed effect of low-carbon and energy-saving efficiency, and promote enterprises Sustainable development also creates greater social value.
(This article is reproduced from Ceramic Information)
