Hydrodynamics and Heat Transfer in Tubular-Grid Packing of Column Apparatus
The paper presents experimental studies of hydraulic resistance and heat transfer in a tubular-lattice packing, which is a package of tubes with spiral turbulators. Smooth tubes and tubes with spiral turbulators made of M1 copper with a winding pitch of turbulators s/dэ=5,11-14,2 were used as experimental sections. Experiments on hydraulic resistance have established that with increasing flow velocity, the function Eu=f(Re) has a descending character both for smooth tubes and for tubes with turbulators in the entire range of Reynolds numbers Re=(0,02-30) 104. It has been revealed that with an increase in the winding pitch of turbulators and the placement of tubes in the tube sheet, the hydraulic resistance decreases significantly. By generalizing the experimental data, a formula for calculating the hydraulic resistance was derived in the form of Eu = f (Re, t/dэ, s/dэ), the error of which does not exceed 9.8%. Heat transfer during cross-flow of the coolant in pipes with spiral turbulators in a tubular-lattice packing relative to the gas and liquid phases moving in countercurrent tends to increase with increasing liquid phase velocity. A similar tendency is maintained for all functional dependencies in the form of K = f (Reж) regardless of the winding pitch of the turbulators s/dэ and gas phase velocities. The use of tubular-lattice packing with spiral turbulators made it possible to achieve heat transfer intensification by 1,14-1,53 times and maintain the calculated temperature along the column height for the effective flow of the rectification process.