Jet mixing in tall tanks: Comparison of methods for predicting blend times

Grenville, Richard K.; Tilton, J.N.

doi:10.1016/j.cherd.2011.05.014

Cited by 21 publications

(27 citation statements)

References 5 publications

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“…The proliferation of computational packages in recent years has also allowed several computational studies to examine the flow patterns that develop in mixing tanks that use submerged jets [8][9][10]. Patwardhan and Gaikwad [11] provide an excellent review of the status of the field until 2003.…”

Section: Introductionmentioning

confidence: 98%

Flow regimes in the mixing of municipal sludge simulant using submerged, recirculating jets

Bhattacharjee

Kennedy

Eshtiaghi

et al. 2015

Chemical Engineering Journal

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Section: Introductionmentioning

confidence: 98%

Flow regimes in the mixing of municipal sludge simulant using submerged, recirculating jets

Bhattacharjee

Kennedy

Eshtiaghi

et al. 2015

Chemical Engineering Journal

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“…They also showed that the mixing time is significantly increasing when the injection angle is less than 15º. Further, Grenville and Tilton (2011) extended their works by studying the mixing time in various tank geometries (0.2 < H/D < 4). They found that their jet turbulence model fitted all data for 0.2 < H/D < 3.…”

Section: Introductionmentioning

confidence: 89%

On the computational fluid dynamics (CFD) analysis of the effect of jet nozzle angle on mixing time for various liquid heights

Bumrungthaichaichan¹,

Jaiklom²,

Namkanisorn³

et al. 2016

Sci. Res. Essays

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In the present work, the effect of nozzle angle (22.5º, 45º and 67.5º) on mixing time for jet mixing tanks with the various ratios of liquid height (H) to tank diameter (D), including 0.5, 1, and 1.5, are studied by using computational fluid dynamics (CFD). The results revealed that CFD model with standard k-epsilon is successfully employed to predict the concentration profiles and mixing time by using the fine mesh and second order upwind scheme. The simulated results showed that the different jet nozzle angles result in different flow patterns. The results also indicate that the mixing time is mainly a function of the jet potential core length. Moreover, the jet path length or jet centerline velocity (jet kinetic energy) is considered as the secondary effect on mixing time, which depends on the tank geometry.

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“…Grenville and Tilton investigated blending of liquids with jets in tanks. 14,15 The tanks ranged in diameter from 0.6 m to 4 m. The blending times ranged from 20 -5,000 seconds. For the conditions that are most representative of the DWPF SRAT (based on power per unit mass), the blending time was ~ 100 seconds.…”

Section: Newtonian Fluidsmentioning

confidence: 99%

“…Three quad volute slurry pumps were operating at 1500 rpm (1020 gpm per 3-inch nozzle). f The mean measured cleaning radius of the pumps was 6.6 m when operating at 2200 rpm, so using the pump affinity laws and assuming the cleaning radius is proportional to the pump speed, the expected cleaning radius is 4.5 m. The height of the fluid was 1.95 m. Assuming a fluid density of 1.35g/mL, and treating the mixed region as a cylinder (from rotation of the pumps) with diameter 6.6 m and height of 1.95 m, the power per unit volume was calculated with equations [12], [13], and [14]. 1.7 10 for two nozzles e The actual head space volume is likely less, but no volume is given for the supernate in the tank.…”

Section: Tank 51 Operating Experiencementioning

confidence: 99%

Retained Hydrogen Literature Study for DWPF

Hansen

2019

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SRNL-STI-2019-00394 Revision 0 vi volume, purge rate, and power input, this data cannot be directly applied to the DWPF, but it is important to note that hydrogen is released over a finite time, rather than instantaneously. Previous work by SRNL and PNNL has measured the rheology of Hanford sludge, and shown the rheology (i.e., yield stress or shear strength) to increase as the sludge is allowed to settle. Changes in sludge rheology need to be considered when assessing changes to the DWPF retained hydrogen program. A comparison of buoyancy and inertial forces under SRAT operating conditions (1-10 Pa yield stress, 1.38 g/mL density, 65 or 130 rpm, 9,000 gallons of feed) on the bubbles (approximated as 300 micron diameter) found the inertial forces to be more than 350,000 times larger than the buoyancy forces. With this ratio of forces, the gas bubbles generated will follow the fluid motion in the SRAT, and only release when they reach the slurry-vapor interface. An informal Lattice Boltzmann Computation Fluid Dynamics calculation was performed on a SRAT type vessel. The liquid was assumed to have a density of 1 g/mL and a viscosity of 20 cP. In the simulation, approximately 50% of the bubbles were released to the vapor space over ~80 seconds. The simulation showed the bubbles to follow the liquid flow, and only release when they reached the liquid surface.

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Jet mixing in tall tanks: Comparison of methods for predicting blend times

Cited by 21 publications

References 5 publications

Flow regimes in the mixing of municipal sludge simulant using submerged, recirculating jets

Flow regimes in the mixing of municipal sludge simulant using submerged, recirculating jets

On the computational fluid dynamics (CFD) analysis of the effect of jet nozzle angle on mixing time for various liquid heights

Retained Hydrogen Literature Study for DWPF

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