Flow Characteristic of Hydraulic Headbox Based on Complementary Pulp Distribution

In order to study effect of complementary pulp distribution, computational fluid dynamic (CFD) was used to research flow characteristic of hydraulic headbox based on complementary pulp distribution. Mass flow rate out of mixing chamber and velocity distribution at slice of headbox were experimented. The results showed that because of simplified design, there were a little gradient of velocity and pressure which caused nonuniform distribution of mass flow rate out of branch pipes. Distribution of mass flow rate was ascented from inlet of header to outlet and the deviaton was -2.33% and 1.82%. There was intense interference between the jets of branch pipes in mixing chamber and the jets could be sufficiently and complementarily mixed in rows and ranks. But the interference in the jets caused that the jets got together to central section of mixing chamber and mass flow rate out of mixing chamber in centre was higher than two sides, the maximum of deviation was 0.538%. Distribution of velocity of pulp stock at slice of headbox was very gentle and curve of distribution had fluctuation, but a little. The maximum deviation of velocity was only 0.175%. From the results of experiment, the test values of mass flow rate out of mixing chamber were inosculated with the calculated values and tested values of velocity at slice of headbox were in accordance with the calculated values. The results of experiment explained that the method of complementary pulp distribution was reasonable and could obviously improve performance of pulp distribution of hydraulic headbox.