What are the ways to slow down the carbonization and coking of heat transfer oil?

In order to slow down the formation speed of coking and prolong the service life of the heat transfer oil, measures should be taken from the following aspects: 1 choice The suitable brand of heat transfer oil is regularly monitored for the change trend of its physical and chemical indicators. 2 The heat transfer oil is classified according to the highest use temperature. Among them, mineral heat transfer oil mainly includes l-qb280, l-qb300 and l-qc320. The maximum operating temperature is 280℃, 300℃ and 320℃ respectively. 3 According to the maximum heating temperature of the heating system, select the appropriate brand and quality heat transfer oil that meets the SH/t0677-1999 'heat transfer oil' standard. At present, the recommended maximum operating temperature of some heat transfer oils on the market does not match the actual measurement results, which will mislead users. 4 The heat transfer oil prepared from refined base oil with excellent thermal stability, high temperature antioxidant and anti-scaling additives should be used. High-temperature antioxidants can effectively delay the oxidation and thickening of heat transfer oil during operation. The high-temperature anti-scaling agent can dissolve the coking in the furnace tube and pipeline and disperse it in the heat transfer oil. Finally, it will be filtered through the bypass filter of the system to keep the furnace tubes and pipes clean. 5 The heat transfer oil is used once every three months or half a year, and its viscosity, flash point, acid value and residual carbon are four indicators for trace analysis. When two indicators exceed the specified limit (the carbon residue is not more than 1.5%, The acid value is not more than 0.5 mgKOH/g, the flash point rate is not more than 20%, and the viscosity change rate is not more than 15%), you should consider adding all or part of the new oil to the oil. Reasonable design and installation of the heating system The design and installation of the heat-conducting oil heating system should strictly follow the design rules of the hot oil stove formulated by the relevant state departments to ensure the safe operation of the heating system. Safety countermeasures (1) Ensure the safety of equipment The heat transfer oil heating system should be managed as a pressure equipment to ensure that the heating equipment is intact and leak-free, otherwise the consequences will be very serious. During use, the wall thickness and compressive strength of the equipment should be measured regularly, and pressure gauges, safety valves and blow-out pipes should be installed on the equipment and pipelines. (2) Strict and safe operation When using the thermal oil boiler diesel burner, the temperature should not exceed 350°C to prevent the temperature from rising above the pressure and causing danger. In order to avoid overheating of the pipe wall on the heating surface of the heat transfer oil, the flow of the heat transfer oil should be turbulent, that is, Reynolds number Rc> 10000, and have a certain speed, so as to reduce the thickness of the boundary layer when flowing over the heating surface. During the heating operation, the circulating pump with the heated body is not allowed to stop. When the thermal load is reduced or temporarily stopped, the bypass return valve should be opened to adjust the flow of the system so that the heat transfer oil in the pipe has sufficient flow and velocity. The heating furnace starts at the beginning of air preheating of the heating surface pipes and system pipes. When the ignition starts to heat up, the heat transfer oil has low temperature, high viscosity, slow speed, and thick film layer. The heating speed must be strictly controlled, generally below 40-50℃/h, in order to avoid local heat overheating. When the temperature of the circulating heat transfer oil is high but the temperature of the thermal equipment cannot be increased, the outlet temperature of the heat transfer oil should not be increased blindly, and thermal equipment, such as a scale, should be used. When using heat transfer oil, pay attention to the temperature and pressure at the beginning of the startup The relationship between. If the pressure is too high and the temperature is too low, it means that there is water and should be exhausted in time; if the pressure is low and the temperature is high, it means that the heat transfer oil is insufficient. When the system stops running, the heat transfer oil circulating pump should continue to run for a period of time. After the heat carrier is cooled, all the heat transfer oil in the system should be returned to the storage tank, especially if there is no residual heat on the heating surface. (3) Ensure the heat conduction of oil and water. It is forbidden to mix heat transfer oil with water or other low-boiling impurities and flammable and explosive substances. When starting, the water in the system should be drained first, then the intake valve and check valve should be opened, heating according to the regulations, to remove the water in the heat carrier; the newly added or added heat transfer oil must be preheated and dehydrated before being added. When eliminating water, first open the air valve, and then use a small flame to increase the temperature of the heat transfer oil to 150°C at a rate of 5°C/h to allow the water to evaporate and escape. Then lower the exhaust valve and raise the temperature to 250°C at a rate of 10°C/h. During the heating process, if there is water knocking sound or high pressure, immediately open the exhaust valve to discharge water vapor, and then close the exhaust valve to start. When stopping the furnace, close the steam valve of the light oil burner of the heat-conducting oil furnace after releasing the heated material to avoid material leakage into the system. (4) Removal of coking and scaling. In production practice, it is safe for the coking thickness to be less than 2mm, and the coking layer in the furnace tube is between 0 and 1.5mm. At this time, the continuous accumulation of the coking layer is roughly balanced with the melting amount washed by the heat carrier. The thickness of the coke layer in the furnace tube can be measured by an ultrasonic thickness gauge. A filter should be installed at the inlet of the circulating pump to remove suspended polymers and carbon particles precipitated by local overheating caused by chemical changes. The filter should be easy to disassemble and replace in order to clean up the residue and impurities regularly to ensure the filtering effect. (5) Strengthening safety management should pay attention to formulating and implementing technical specifications and management regulations for the operation of hot oil heating equipment, and strictly abide by relevant laws, regulations and safety operating procedures. The heat conduction oil heating operation should have a complete emergency treatment plan, especially to prevent the occurrence of overflow, spraying materials, leakage, overload and disease operations. Once the leakage point, stop the leakage immediately and replace the insulating cotton. (6) Set up safety devices Set up temperature, pressure, flow, liquid level automatic adjustment system, alarm system and safety release device to ensure the sensitive use of instruments. During the heating operation, if the pressure suddenly rises, immediately open the exhaust valve to release the pressure, and close the valve of the heat carrier pipe to the heating device. ! If you are interested in diesel combustion engines, please contact us for a quote!