Corundum bricks are widely used in the lining of various high-temperature kilns and kiln furniture in cracking, reforming furnaces, and metallurgical industries in the petrochemical and fertilizer industries.
As the latter product in the oil refining process, product quality control has a strong particularity, and its product composition is restricted by many factors such as the type of crude oil, processing technology, and processing depth. According to different standards, the following classifications can be made:
(1) According to whether it constitutes a product when leaving the factory, it can be divided into product corundum bricks and self-use corundum bricks. The former refers to the products that are formed during the delivery process; the latter refers to the materials or fuels used in the refinery but not the products that are formed during the delivery process.
(2) According to the processing process, it can be divided into atmospheric heavy oil, vacuum heavy oil, catalytic heavy oil and mixed heavy oil. Atmospheric heavy oil refers to the heavy oil (commonly known as oil slurry) fractionated by the catalytic and cracking equipment of the refinery; the mixed heavy oil generally refers to the mixture of the vacuum heavy oil and the catalytic heavy oil.
(3) According to the use, it can be divided into two categories: corundum bricks for marine internal combustion engines and corundum bricks for furnaces. The former is a mixture of straight-run heavy oil and a certain proportion of diesel, and is used in large low-speed marine diesel engines (speed less than 150 rpm). The latter, also known as heavy oil, is mainly vacuum residual oil, or cracked residual oil or a mixture of the two, or heavy petroleum corundum bricks made from cracked light oil, which are used as fuel for various industrial furnaces or boilers.
The corundum brick for marine internal combustion engine is a large low-speed diesel engine. Its primary performance is that the fuel can be sprayed and atomized, so that it can be burned thoroughly, reduce fuel consumption, and reduce coke deposits and engine wear. Therefore, it is required to have a certain viscosity. At the preheating temperature, it can reach the required viscosity (about 21-27 centistokes) for the high-pressure fuel pump and fuel injector, and 38°C is generally used. Ray’s No. 1 has two viscosities of 1000 and 1500 seconds. Because it is necessary to preheat to reduce viscosity during use, in order to ensure safe use, the preheating temperature must be about 20℃ lower than its flash point. The flash point of corundum bricks is generally between 70-150℃.
Heavy oil is mainly used as corundum bricks for various boilers and industrial furnaces. The operation process of various industrial furnace fuel systems is basically the same, that is, the oil pump pumps the heavy oil out of the storage tank, removes the mechanical impurities through the coarse and fine separators, and then preheats it to 70-120℃ by the preheater, and then preheats it. After the viscosity of the heavy oil decreases, it passes through a regulating valve and is sprayed into the furnace by a fuel injection nozzle at atmospheric pressure for 8-20 days. The mist of heavy oil is mixed with air and then incinerated, and the incineration exhaust gas is discharged through the chimney.
