skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Performance Analysis for Mixing Pumps in Tank 18

Technical Report ·
DOI:https://doi.org/10.2172/799719· OSTI ID:799719

In support of sludge suspension and mixing operations in Tank 18, flow evolution models were developed and performance calculations completed for the advanced design mixer pump (ADMP) and the modified ADMP (MADMP). The MADMP was being considered as a replacement for the ADMP in Tank 18. The models and calculations were based on prototypic tank geometry and expected normal operating conditions as defined by Waste Removal Closure (WRC) Engineering. Computational fluid dynamics models of both the TNX full tank experimental facility and Tank 18 were developed using the FLUENT(tm) code. TNX test data were used to benchmark the models and assess the efficiency of sludge suspension and removal operations in the 85 ft tank. The models employed a three-dimensional approach, a two-equation turbulence model, and a stepped-rotation approximation to estimate pump rotation effects. A two-dimensional approach was also used as a scoping analysis to examine multi-dimensional effects of fluid motion on the flow circulation patterns in the tank. The results were verified by both TNX test data and literature data. Local velocity was used as a measure of slurrying and mixing capability. The results showed that normal operations in Tank 18 with the existing ADMP mixer and a 70 inch liquid level provide adequate sludge removal in most regions of the tank. The exception is the region within about 2 ft of the wall, assuming the minimum velocity required to suspend waste sludge is 2.27 ft/sec. Further results showed that the time to reach a steady-state flow pattern was affected by both pump rotation and pump location. Sensitivity studies showed that a higher tank level and the smaller nozzle size would result in better performance in suspending and removing the sludge. The results also showed that the MADMP mixer has the best sludge removal capacity. Computational results for two different fluids, water and a typical slurry, showed that the maximum clearing distance was not sensiti ve to the slurry fluid properties.

Research Organization:
Savannah River Site (SRS), Aiken, SC (United States)
Sponsoring Organization:
US Department of Energy (US)
DOE Contract Number:
AC09-96SR18500
OSTI ID:
799719
Report Number(s):
WSRC-TR-2001-00391; TRN: US0202309
Resource Relation:
Other Information: PBD: 16 Apr 2002
Country of Publication:
United States
Language:
English