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Title: Flow velocity analysis for avoidance of solids deposition during transport of Hanford tank waste slurries

Abstract

This engineering analysis calculates minimum slurry transport velocities intended to maintain suspensions of solid particulate in slurries. This transport velocity is also known as the slurry flow critical velocity. It is not universally recognized that a transfer line flow velocity in excess of the slurry critical velocity is a requirement to prevent solids deposition and possible line plugging. However, slurry critical velocity seems to be the most prevalent objective measure to prevent solids deposition in transfer lines. The following critical velocity correlations from the literature are investigated: Durand (1953), Spells (1955), Sinclair (1962), Zandi and Gavatos (1967), Babcock (1968), Shook (1969), and Oroskar and Turian (1980). The advantage of these critical velocity correlations is that their use is not reliant upon any measure of bulk slurry viscosity. The input parameters are limited to slurry phase densities and mass fractions, pipe diameter, particle diameter, and viscosity of the pure liquid phase of the slurry. Consequently, the critical velocity calculation does not require determination of system pressure drops. Generalized slurry properties can, therefore, be recommended if the slurry can be adequately described by these variables and if the liquid phase viscosity is known. Analysis of these correlations are presented, indicating that themore » Oroskar and Turian (1980) models appear to be more conservative for smaller particulate sizes, typically those less than 100 microns diameter. This analysis suggests that the current Tank Farms waste compatibility program criteria may be insufficient to prevent particulate solids settling within slurry composition ranges currently allowed by the waste compatibility program. However, in order to relate a critical velocity associated with a certain slurry composition to a system limit, a means of relating the system capabilities to the slurry composition must be found. Generally, this means expressing the bulk or effective viscosity of the slurry being transferred to some more readily obtainable variable, such as slurry density or solids concentration. No universally recognized model exists to accomplish this, and there is great uncertainty among results from those models that do exist. Following this analysis of critical velocity correlations, a recommendation is made to revise the waste transfer compatibility program criteria relating to solids transport. The new criteria states that a special engineering evaluation is required for any waste transfer that involves particulate solid transport. This evaluation is needed to gain a measure of confidence that the critical velocity for a given slurry composition is within the capabilities of the transfer system.« less

Authors:
Publication Date:
Research Org.:
HNF Hanford Site (US)
Sponsoring Org.:
US DOE Office of Environmental Management (US)
OSTI Identifier:
781576
Report Number(s):
HNF-2728-REV0; EW3120074
EW3120074; TRN: US0111192
DOE Contract Number:  
AC06-96RL13200
Resource Type:
Technical Report
Resource Relation:
Other Information: PBD: 25 Feb 1999
Country of Publication:
United States
Language:
English
Subject:
12 MANAGEMENT OF RADIOACTIVE WASTES, AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES; CRITICAL VELOCITY; PRESSURE DROP; SLURRIES; STORAGE FACILITIES; HYDRAULIC TRANSPORT; WASTE RETRIEVAL; FLOW RATE

Citation Formats

ESTEY, S.D.. Flow velocity analysis for avoidance of solids deposition during transport of Hanford tank waste slurries. United States: N. p., 1999. Web. doi:10.2172/781576.
ESTEY, S.D.. Flow velocity analysis for avoidance of solids deposition during transport of Hanford tank waste slurries. United States. doi:10.2172/781576.
ESTEY, S.D.. Thu . "Flow velocity analysis for avoidance of solids deposition during transport of Hanford tank waste slurries". United States. doi:10.2172/781576. https://www.osti.gov/servlets/purl/781576.
@article{osti_781576,
title = {Flow velocity analysis for avoidance of solids deposition during transport of Hanford tank waste slurries},
author = {ESTEY, S.D.},
abstractNote = {This engineering analysis calculates minimum slurry transport velocities intended to maintain suspensions of solid particulate in slurries. This transport velocity is also known as the slurry flow critical velocity. It is not universally recognized that a transfer line flow velocity in excess of the slurry critical velocity is a requirement to prevent solids deposition and possible line plugging. However, slurry critical velocity seems to be the most prevalent objective measure to prevent solids deposition in transfer lines. The following critical velocity correlations from the literature are investigated: Durand (1953), Spells (1955), Sinclair (1962), Zandi and Gavatos (1967), Babcock (1968), Shook (1969), and Oroskar and Turian (1980). The advantage of these critical velocity correlations is that their use is not reliant upon any measure of bulk slurry viscosity. The input parameters are limited to slurry phase densities and mass fractions, pipe diameter, particle diameter, and viscosity of the pure liquid phase of the slurry. Consequently, the critical velocity calculation does not require determination of system pressure drops. Generalized slurry properties can, therefore, be recommended if the slurry can be adequately described by these variables and if the liquid phase viscosity is known. Analysis of these correlations are presented, indicating that the Oroskar and Turian (1980) models appear to be more conservative for smaller particulate sizes, typically those less than 100 microns diameter. This analysis suggests that the current Tank Farms waste compatibility program criteria may be insufficient to prevent particulate solids settling within slurry composition ranges currently allowed by the waste compatibility program. However, in order to relate a critical velocity associated with a certain slurry composition to a system limit, a means of relating the system capabilities to the slurry composition must be found. Generally, this means expressing the bulk or effective viscosity of the slurry being transferred to some more readily obtainable variable, such as slurry density or solids concentration. No universally recognized model exists to accomplish this, and there is great uncertainty among results from those models that do exist. Following this analysis of critical velocity correlations, a recommendation is made to revise the waste transfer compatibility program criteria relating to solids transport. The new criteria states that a special engineering evaluation is required for any waste transfer that involves particulate solid transport. This evaluation is needed to gain a measure of confidence that the critical velocity for a given slurry composition is within the capabilities of the transfer system.},
doi = {10.2172/781576},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Thu Feb 25 00:00:00 EST 1999},
month = {Thu Feb 25 00:00:00 EST 1999}
}

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