High temperature heat transfer oil is widely used. Viscous colloid will be produced during circulation. Some colloid will be filtered out through the filter, and a small part of colloid will adhere to the inner wall of the furnace tube, which is very easy to form coke. The status quo of coke formation is that the heat transfer rate of the heat transfer oil furnace can not meet the requirements. There is something important in the furnace tube, and bubbles will be generated on the furnace tube. Continuing to heat the bubble will crack and leak oil, and it will burn when encountering the fire source, From this, we can know the importance of cleaning the coking in the heat transfer oil furnace. Generally, the following methods can be used to deal with the coking problem of heat transfer oil. Method 1: Discharge heat transfer oil - steam purging stagnant oil - alkaline cleaning agent - water flushing - pickling - passivation Principle: alkaline water has a good effect on cleaning oil and carbon deposition at medium temperature. After treatment, the inner wall of the test piece will still retain oil and dense graphitized high temperature carbon deposition layer, which must be further removed by acid washing to avoid the residual carbon layer affecting the quality of heat transfer oil and heat transfer effect. The two-step cleaning process of alkaline washing and acid washing is used for carbon deposition in heat medium furnaces and pipes. It has the advantages of very high cleaning rate, low temperature, non-toxic and low cleaning cost, This method can remove the scale layer, but there are many processes, including acid and alkali corrosion, which shortens the service life of the machine and causes secondary pollution. If it is carried out under the condition of shutdown, its production will be affected. Method 2: Discharge heat transfer oil - steam purging stagnant oil - organic solvent cleaning solution - passivation Principle, The residue is mixed with coal for combustion, reducing the cost and reducing environmental pollution, but the cleaning agent is volatile, low safety and high cost. Method 3: Add additives to the running heat transfer oil to flake the carbon deposit, and then clear and filter it to remove the oil residue Principle, In addition, this process is simple and cost saving. The heat transfer oil after removing fraud can still be reused without polluting the environment. The chemical cleaning method is a trend to clean the heat transfer oil pipeline. 
How to Prevent Coking of Heat Transfer Oil
1. Anti coking method of heat transfer oil - mechanical method
When conducting experiments with heat transfer oil, we will find that when the object coefficient is lower than 2000, the internal coking rate will increase, but when the value is greater than 4000, it will become smaller. Therefore, our researchers found that the coking speed of liquid is related to its flow speed. Therefore, when using machinery at ordinary times, we should consider that the flow speed of equipment is greater than 2M/S, so that the purpose of equipment coke prevention can be better achieved. 2. Anti coking method of heat transfer oil - chemical method In contrast, chemical method can solve the problem of liquid coking. It is necessary to emphasize the process of equipment coking again. Coking of heat transfer oil is the process of asphalt resin generated moving to the heat transfer surface and the process of resin on the surface being absorbed by heat. Therefore, the so-called chemical method can well prevent the process of heat transfer oil generating asphalt. Generally, we will choose high temperature anti coking agent, The role of this chemical substance is to reduce the generation of asphalt through high temperature, and at the same time, a special colloid will be generated to suspend in the oil, and the heat will be transferred synchronously through the use of filters, finally achieving the purpose of chemical coke prevention.
