Purpose of heating furnace drying, required conditions, steps, and precautions
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Purpose of furnace drying: 1. For newly built heating furnaces, whose linings contain large amounts of adsorbed water and crystalline water, furnace drying enables the gradual removal of this natural water and crystalline water from the lining. This prevents rapid evaporation of water during normal heating, which could otherwise cause structural damage, thereby enhancing the strength and service life of the furnace walls； 2. Test for deformation defects in the steel frame foundation and various components, to prevent cracking and deformation when the temperature rises ； 3. Check whether the system instruments are in good condition ； 4. Check whether the fuel gas system is operating effectively. Meeting the requirements: 1. A detailed furnace drying plan has been developed and approved by the relevant departments, and the personnel involved have studied this plan ； 2. Device purging, flushing, and water commissioning are complete ； 3. Coordinate with departments such as scheduling and utilities to ensure the supply of fuel gas and electricity ； 4. Develop record forms and acceptance forms for furnace drying ； 5. The heating furnace has passed the construction acceptance inspection ； 6. The furnace wall shall be allowed to dry naturally at ambient temperature (25~40°C) for more than 72 hours ； 7. The hydraulic testing of furnace tubes and similar components is complete, and the fuel gas system is ready to supply gas ； 8. The individual test run of the drum blower was successful. Step 1: The furnace drying process is divided into two phases: warming up the furnace and drying it. 2. Preheating refers to the process of introducing steam into the furnace tubes before lighting the furnace and raising its temperature, in order to bake the furnace tubes and furnace chamber at a low temperature; this preheating process takes approximately 1 to 2 days ； 3. The heating rate of the furnace should be controlled at ≤15°C/h, and the burners should be switched every 4–8 hours ； 4. During furnace drying, the steam temperature should be controlled at: carbon steel ≯ 350°C, stainless steel ≯ 480°C℃ ； 5. The drying of the fractionation furnace can be carried out simultaneously with the oil circulation in the system, while the reaction furnace can be tested under hot conditions at the same time as nitrogen drying in the system. Precautions: 1. During the constant temperature period, keep temperature fluctuations at ≤10℃ ； 2. When igniting the main burners, do so diagonally, and switch the burners at regular intervals ； 3. Keep the temperatures at various points in the furnace as balanced as possible; adjust the corresponding burners when there are significant deviations ； 4. Avoid direct flame contact with the furnace tubes to prevent excessively high temperatures.
Purpose: To enable the drying and sintering of newly installed refractory materials. Requirements: Fuel gas and steam pipeline systems must be available for unauthorized use； The furnace drying process is ready ； Plans and emergency response plans are in place ； Operators must be trained and qualified before taking up their posts ； Step: Complete the furnace heating process ； The fire-extinguishing steam is led to the front of the furnace for standby use ； Establish negative pressure in the furnace chamber ； Nozzles required to ignite the drying furnace ； Raise the temperature strictly in accordance with the furnace heating curve provided by the manufacturer ； Precautions: Analyze the furnace before ignition; it can be started only if the combustible gas level is within acceptable limits ； Raise the temperature strictly in accordance with the furnace heating curve provided by the manufacturer; rapid temperature increase is strictly prohibited.
Purpose of furnace drying: After a heating furnace is built or overhauled, and after pressure testing is successful, the furnace must be dried before it can be put into use. Its purpose is to gradually remove the moisture accumulated during the construction of the furnace wall before it is put into use, and to allow the refractory mortar to undergo sufficient sintering. This prevents cracks or deformation in the furnace lining, as well as the splitting and collapse of the furnace wall, that could occur due to a rapid increase in temperature inside the furnace, massive vaporization of moisture, and resulting volume expansion when the facility starts operating. Thermal load testing is carried out on the heating system, the equipment belonging to the heat absorption system, as well as the process pipelines and automatic control systems, in order to evaluate the performance of all burners and the behavior of the furnace components under thermal conditions.
I don’t quite understand this; it’s something newbies need to learn**
It’s quite basic; the furnace wasn’t heated properly, so the lining was ruined
The original poster explained it so well; I learned something :)
I am a manufacturer and supplier of refractory materials. For heating furnaces in the petrochemical industry, are clay bricks, high-alumina bricks, or silicon carbide bricks the appropriate refractory materials? What type of furnace is a heating furnace? Thank you for your advice and reply
I used to specialize in tubular heating furnaces and incinerators; the purpose of drying these furnaces is what was mentioned on the third floor – to gradually remove the crystalline water from the lining and inside the furnace, in accordance with a specific drying curve.