Resuspension of non-Newtonian slurries by submerged jet-nozzles

Executive SummaryThe Hanford Site in Washington State manages 177 underground storage tanks containing approximately 250,000 m 3 of waste generated during past defense reprocessing and waste management operations. These tanks contain a mixture of sludge, saltcake and supernatant liquids. The insoluble sludge fraction of the waste consists of metal oxides and hydroxides and contains the bulk of many radionuclides such as the transuranic components and 90 Sr. The saltcake, generated by extensive evaporation of aqueous solutions, consists primarily of dried sodium salts. The supernates consist of concentrated (5-15 M) aqueous solutions of sodium and potassium salts. The 177 storage tanks include 149 single-shell tanks (SSTs) and 28 double-shell tanks (DSTs).Ultimately the wastes need to be retrieved from the tanks for treatment and disposal. The SSTs contain minimal amounts of liquid wastes, and the Tank Operations Contractor is continuing a program of moving solid wastes from SSTs to interim storage in the DSTs. The Hanford DST system provides the staging location for waste feed delivery to the Department of Energy (DOE) Office of River Protection's (ORP) Hanford Tank Waste Treatment and Immobilization Plant (WTP). The WTP is being designed and constructed to pretreat and then vitrify a large portion of the wastes in Hanford's 177 underground waste storage tanks.The retrieval, transport, treatment and disposal operations involve the handling of a wide range of slurries. Solids in the slurry have a wide range of particle size, density and chemical characteristics. Depending on the solids concentration the slurries may exhibit a Newtonian or a non-Newtonian rheology.The extent of knowledge of the physical and rheological properties is a key component to the success of the design and implementation of the waste processing facilities. These properties are used in engineering calculations in facility designs. Knowledge of the waste properties is also necessary for the development and fabrication of simulants that are used in testing at various scales. The expense and hazards associated with obtaining and using actual wastes dictates that simulants be used at many stages in the testing and scale-up of process equipment. The results presented in this report should be useful for estimating process and equipment performance and provide a technical basis for development of simulants for testing.The purpose of this document is to provide an updated summary of the Hanford waste characterization data pertinent to safe storage, retrieval, transport and processing operations for both the tank farms and the WTP and thereby identify gaps in understanding and data. Important waste parameters for these operations are identified by examining examples of relevant mathematical models of selected phenomena including: The data sets in (UDS composition and particle density, UDS primary particle size and shape, UDS particle size distributions [PSDs], and estimated particle size and density distributions [PSDDs]) and Poloski et al. (2007) ...

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“…Poirier (2004) and Reshma et al (2007) developed the following formula for the Savannah River and Oak Ridge Sites, respectively.…”

Section: Examples Of Ecr Calculation Modelsmentioning

confidence: 99%

Hanford Waste Physical and Rheological Properties: Data and Gaps

Wells¹,

Kurath²,

Mahoney³

et al. 2011

103

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“…Studies on non-Newtonian media in jet recirculating systems are not common in the literature although some examples do exist [9][10][11][12]. Studies on pulse jets in non-Newtonian media are more developed.…”

Section: Introductionmentioning

confidence: 99%

Control of the mixing time in vessels agitated by submerged recirculating jets

Kennedy

Bhattacharjee²,

Bhattacharya

et al. 2018

R. Soc. open sci.

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Submerged recirculating jet mixing systems are an efficient and economical method of agitating large tanks with a high hydraulic residence time. Much work has been carried out in developing design correlations to aid the predictions of the mixing time in such systems, with the first such correlation being developed nearly 70 years ago. In most of these correlations, the mixing time depends directly on the volume of the vessel and inversely on the injection velocity of the submerged jet. This work demonstrates, for the first time, that the distance between the injection and suction nozzles also significantly affects the mixing time and can be used to control this time scale. The study introduces a non-dimensional quantity that can be used as an adjustable parameter in systems where such control is desired.

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“…He explained that the coefficient of 0.97 of Churnetski's ECR model (Equation 2.13) is smaller than his coefficient of 4.4 (Equation 2.14) possibly because of the friction caused by the tank wall in Churnetski's experiment. Reshman et al (2007) reported the following ECR model for the Savannah River Site application:…”

Section: 6mentioning

confidence: 99%

“…For use at the Savannah River Site, the Savannah River and Oak Ridge Sites developed the following ECR formula by Churnetski (Reshman et al 2007) and Poirier (2004), respectively…”

Section: 6mentioning

confidence: 99%