Research On Long Campaign-service Cooling Stave With Heat Transfer Intensified By Spiral Fluidization And Its Scheme Of Thermal Simulation Test

The service campaign of blast furnaces depends on their cooling equipments'campaign. The water fouling is the most important factor in service campaign of cooling staves. Copper cooling staves have excellent quality of total heat transfer. With closed loop soft water cooling systems applied, their service campaign is up to the level of 15 to 20 years, but they cost huge.The cooling stave intensified by spiral fluidization is studied on in the paper. The technical principle of spiral fluidization lies in installing spiral steel wires within flow channels, which guide cooling water flowing in spiral streamline. The fluidization particles with volume concentration of 2 percent are injected in need of cleaning. When cleaning, the particles flow spirally together with cooling water. Most of particles flow spirally on cylindrical surfaces of flow channels with the action of inertial centrifugal force. So the water fouling is removed quickly and uniformly. Experimental researches on spiral fluidization, the core technology of the stave, are performed for the first time in the paper. And their results show that it only costs 145 seconds to remove the artificial fouling on inner walls of flow channels. In addition, they also reveal that convective heat transfer coefficient between cooling water and inner walls is intensified for more than 50 percent, and that the total flow resistance is equal to 48.7kPa which is lower than total pressure of supply water.The method of theoretical calculation combining with numerical simulation and experiment is applied while researching. The results of theoretical calculation based on heat transfer show that the total heat transfer coefficient from inner wall of cooling tube to hot surface of the stave is 40.7 percent of copper stave's, 14 times of cast-iron stave's and 5.1 times of widely-used cast-steel stave's. While simulating, solution models are created by GAMBIT, and by FLUENT are performed numerical simulation on heat transfer magnitude intensified by spiral fluidization through discrete phase model and temperature field of the stave through 3-dimension steady segregated solution. Results of numerical simulation show that in comparison with tubes without any inserts in, the enhanced magnitude of convective heat transfer is up to 40.4 percent. They also reveal that it is under safety temperature during the stage with fins worn down completely even if there is no slag sticking on hot surface, and that the highest temperature on hot surface is only 85.7 degrees on the condition that a layer of slag thick 30mm uniformly sticks on it.In the end, an experimental theme in thermal simulation, performed in slag notch, is researched and put forward for the first time to test the temperature on hot surfaces, period of forming slag and distribution of slag. It has many remarkable advantages such as short test period, low cost, easy operation, safety and reliability, and so on.