Hydrodynamics in a jet bubbling reactor: Experimental research and mathematical modeling

Abstract

The radial distribution of liquid velocity in the axial direction of a jet bubbling reactor has been measured by experimentation. Three different typical flow structures controlled by liquid jet, gas bubbling, and liquid jet coupled with bubbling are observed. A tank in series model is established on this basis. Calculated values in each region are in good agreement with measured values in jet, bubbling, and wall effect controlled areas. Axial flow rate, radial exchange rate, and jet controlled volume g are analyzed from energy input aspect under different u g and u j. Simulation results indicate that under the synergetic action of the liquid jet and gas bubbling effect, jet controlled area exhibits a "spindle" structure, and its size decreases with the increase of u g. When gas input power occupies about 67% of total energy consumption, the best synergy of liquid jet and gas bubbling is obtained. V

Structural Design and Performance of a Jet-Impinging Type Microbubble Generator

“…The liquid input power of each hole ( P L i ) is calculated through eq , where d L is the hole diameter (m), and Q L i is the liquid volume flow rate through the hole (m 3 /s). The total liquid input power P L = 20 P L i .…”

“…The total liquid input power P L = 20 P L i . The gas input power of each hole ( P G i ) is calculated by eqs and , where Q G i is the gas volume flow rate through the hole (m 3 /s), M is the relative molecular mass of the gas (kg/mol), u 0 is the velocity at the gas hole (m/s), α is the ratio between the largest static pressure and the pressure at the top of the reactor ( P T ), and L 0 is the height of the liquid level without bubbles (m). The total gas input power P G = 20 P G i .…”

Structural Design and Performance of a Jet-Impinging Type Microbubble Generator

“…The liquid input power of each hole ( P L i ) is calculated through eq , where d L is the hole diameter (m), and Q L i is the liquid volume flow rate through the hole (m 3 /s). The total liquid input power P L = 20 P L i .…”

“…The total liquid input power P L = 20 P L i . The gas input power of each hole ( P G i ) is calculated by eqs and , where Q G i is the gas volume flow rate through the hole (m 3 /s), M is the relative molecular mass of the gas (kg/mol), u 0 is the velocity at the gas hole (m/s), α is the ratio between the largest static pressure and the pressure at the top of the reactor ( P T ), and L 0 is the height of the liquid level without bubbles (m). The total gas input power P G = 20 P G i .…”

Classification and identification of gas–liquid dispersion states in a jet bubbling reactor

“…Because the intensity of the disturbance effect of the bubbles on the liquid velocity determines the oscillation of the liquid velocity, it is speculated that the oscillation of the liquid velocity near the wall has significant differences under different gas–liquid dispersion states. In order to verify this conjecture, the axial liquid velocity near the wall at the bottom end of the reactor cylinder under different gas–liquid dispersion states is measured using the Pavlov tube . The experimental results are shown in Figure , where the axial liquid velocity is positive meaning the upward flow direction, and the standard deviation σ is used to characterize the oscillation of the axial liquid velocity.…”

Experimental study on droplet breakup in an orifice jet mixer

“…Subsequently, with different assumptions or objectives, some more models based on the turbulent fluctuation and collision theory were proposed. [19][20][21][22] These models are consistent in the following two aspects: (1) the research systems have a low energy dissipation rate; (2) a binary breakup assumption is adopted. The above models are suitable for the condition of low energy dissipation rates.…”

Structural Design and Performance of a Jet-Impinging Type Microbubble Generator

“…The liquid input power of each hole ( P L i ) is calculated through eq , where d L is the hole diameter (m), and Q L i is the liquid volume flow rate through the hole (m 3 /s). The total liquid input power P L = 20 P L i .…”

“…The total liquid input power P L = 20 P L i . The gas input power of each hole ( P G i ) is calculated by eqs and , where Q G i is the gas volume flow rate through the hole (m 3 /s), M is the relative molecular mass of the gas (kg/mol), u 0 is the velocity at the gas hole (m/s), α is the ratio between the largest static pressure and the pressure at the top of the reactor ( P T ), and L 0 is the height of the liquid level without bubbles (m). The total gas input power P G = 20 P G i .…”

Classification and identification of gas–liquid dispersion states in a jet bubbling reactor

“…Because the intensity of the disturbance effect of the bubbles on the liquid velocity determines the oscillation of the liquid velocity, it is speculated that the oscillation of the liquid velocity near the wall has significant differences under different gas–liquid dispersion states. In order to verify this conjecture, the axial liquid velocity near the wall at the bottom end of the reactor cylinder under different gas–liquid dispersion states is measured using the Pavlov tube . The experimental results are shown in Figure , where the axial liquid velocity is positive meaning the upward flow direction, and the standard deviation σ is used to characterize the oscillation of the axial liquid velocity.…”

Experimental study on droplet breakup in an orifice jet mixer

“…Subsequently, with different assumptions or objectives, some more models based on the turbulent fluctuation and collision theory were proposed. [19][20][21][22] These models are consistent in the following two aspects: (1) the research systems have a low energy dissipation rate; (2) a binary breakup assumption is adopted. The above models are suitable for the condition of low energy dissipation rates.…”

Structural Design and Performance of a Jet-Impinging Type Microbubble Generator

“…The liquid input power of each hole ( P L i ) is calculated through eq , where d L is the hole diameter (m), and Q L i is the liquid volume flow rate through the hole (m 3 /s). The total liquid input power P L = 20 P L i .…”

“…The total liquid input power P L = 20 P L i . The gas input power of each hole ( P G i ) is calculated by eqs and , where Q G i is the gas volume flow rate through the hole (m 3 /s), M is the relative molecular mass of the gas (kg/mol), u 0 is the velocity at the gas hole (m/s), α is the ratio between the largest static pressure and the pressure at the top of the reactor ( P T ), and L 0 is the height of the liquid level without bubbles (m). The total gas input power P G = 20 P G i .…”

Classification and identification of gas–liquid dispersion states in a jet bubbling reactor

“…Because the intensity of the disturbance effect of the bubbles on the liquid velocity determines the oscillation of the liquid velocity, it is speculated that the oscillation of the liquid velocity near the wall has significant differences under different gas–liquid dispersion states. In order to verify this conjecture, the axial liquid velocity near the wall at the bottom end of the reactor cylinder under different gas–liquid dispersion states is measured using the Pavlov tube . The experimental results are shown in Figure , where the axial liquid velocity is positive meaning the upward flow direction, and the standard deviation σ is used to characterize the oscillation of the axial liquid velocity.…”

Experimental study on droplet breakup in an orifice jet mixer

“…Subsequently, with different assumptions or objectives, some more models based on the turbulent fluctuation and collision theory were proposed. [19][20][21][22] These models are consistent in the following two aspects: (1) the research systems have a low energy dissipation rate; (2) a binary breakup assumption is adopted. The above models are suitable for the condition of low energy dissipation rates.…”