Judith Ann Bamberger

On-line ultrasonic density sensor for process control of liquids and slurries

Abstract An on-line ultrasonic density sensor is described in which six transducers are mounted upon a plastic wedge, the base of the wedge being in contact with a liquid or slurry. Ultrasonic beams striking the base at several angles are reflected. The amount of reflection at the plastic–liquid interface depends upon the density of the liquid ρ, the speed of sound c in the liquid, and wedge parameters. By determining the reflection coefficient at two angles, ρ and c can be determined. The sensor can be mounted in a pipeline configuration or submerged for tank applications.

Ultrasonic sensor to measure the density of a liquid or slurry during pipeline transport

This paper describes the design and testing of a computer-controlled sensor for the real-time measurement of the density of a liquid or slurry. It is to be deployed at the US Department of Energys Hanford Site in Richland, WA, to monitor slurry properties during radioactive waste transfers. To demonstrate the sensor performance, tests were carried out using non-radioactive waste simulants and the results will be presented. The sensor is mounted flush with the pipeline wall in a nominal 5-cm (2-in.) pipe spool piece. The design pressure is 2.8 MPa (400 psi). The probe wedge in contact with the slurry was selected to operate up to pH 14, and the probe components were radiation tested at exposures of 1 x 10(6) R. The sensor is applicable for process control of all types of liquids or slurries in pipelines or in vessels.

Self-Calibrating Sensor for Measuring Density through Stainless Steel Pipeline Wall

An ultrasonic instrument to measure the density of a liquid or slurry [1,2] through the stainless steel (SS) pipeline wall is described. By using multiple reflections of the ultrasound within the SS wall, the acoustic impedance (defined as the product of the density of the liquid and the velocity of sound in the liquid) is determined. Thus, the wall is part of the measurement system. The density is obtained by coupling the acoustic impedance measurement with a velocity of sound measurement. Since methods for measuring the time-of-flight (TOF) are well known, the research presented here will focus on the measurement of the acoustic impedance. The self-calibrating feature is very important because the measurement of the acoustic impedance is independent of changes in the pulser voltage. The objective is to develop an ultrasonic sensor that (1) can be attached permanently to a pipeline wall, possibly as a spool piece inserted into the line and (2) can clamp onto an existing pipeline wall and be movable to another location. The self-calibrating feature is very important because the signal strength is sensitive to the pressure on the clamp-on sensor. A sensor for immersion into a tank could also be developed. A U.S. Patent application has been filed.Copyright

On-Line Sensor to Measure the Density of a Liquid or Slurry

An on-line sensor to measure the density of a liquid or slurry is of interest for many different applications, such as measuring the density of a reagent in a pipeline during production or transport or measuring the density of a slurry in a radioactive waste storage tank on the Hanford reservation. Such a real-time, in-situ sensor is shown in Figure 1. The ultrasonic density sensor consists of longitudinal (B, C, D, E, and F) and shear wave (A) transducers mounted upon a plastic wedge. Density is measured based on the reflection of ultrasound at the wedge-liquid interface.

Ultrasonic technologies for advanced process monitoring, measurement, and control

Ultrasonic signals are well suited for characterizing of liquids, slurries, and multiphase flows. Ultrasound sensor systems provide real-time insitu measurements or visualizations, and the sensing systems are compact, rugged, and relatively inexpensive. The objective is to develop ultrasonic sensors that 1) can be attached permanently to a pipeline wall, possibly as a spool piece inserted into the line, and 2) can clamp onto an existing pipeline wall and be movable to another location. Two examples of systems based on pulse-echo and transmission signal analysis are used to illustrate some of the capabilities of ultrasonic online measurements with technologies that have applications in the nuclear, petrochemical, and food processing industries.

CHARACTERIZING PULSATING MIXING OF SLURRIES

This paper describes the physical properties for defining the operation of a pulse jet mixing system. Pulse jet mixing systems operate with no moving parts located in the vessel or in the fluid to be mixed. Pulse tubes submerged in the vessel provide a pulsating flow that mixes the fluid due to a controlled combination of applied pressure to expel the fluid from the pulse tube nozzle followed by suction to refill the pulse tube through the same nozzle. For mixing slurries nondimensional parameters to define mixing operation include slurry properties, geometric properties and operational parameters. Primary parameters include jet Reynolds number and Froude number; alternate parameters may include particle Galileo number, particle Reynolds number, settling velocity ratio, and hindered settling velocity ratio. Rating metrics for system performance include just suspended velocity, concentration distribution as a function of elevation, and blend time.Copyright

Evolution of a Non-Invasive Sensor for Fluid Density and Solids Concentration Measurement Using Ultrasound

This paper describes the evolution of an ultrasonic sensor to non-invasively measure slurry density and solids concentration. Three generations of probe are discussed: 1) density sensor, 2) densimeter, and 3) fluid and solids monitor. The initial application was to measure slurry density during radioactive waste transport. The probe uses ultrasonic signal reflection at the fluid-pipe wall interface to quantify density in situ in real time and signal attenuation to evaluate solid concentration. In the latest configuration, the transducers are mounted on the wall of the pipe spool piece. This instrument was selected for monitoring radioactive waste transport based on several characteristic features: the sensing surface is non-intrusive and does not disrupt the slurry flow, instrument performance is not affected by slight amounts of entrained air that could be present during waste retrieval and transfer; nor is it affected by electromagnetic noise from nearby pumps and other equipment; and the instrument is compact. The densimeter has been deployed at Hanford tank SY-101 in the prefabricated pump pit process manifold to monitor slurry properties during radioactive waste transfers. To qualify densimeter performance prior to manifold installation in the radioactive pipeline, the probe was installed in the process manifold and performance was evaluated during tests using non-radioactive waste simulants over the density range from 1000 to 1500 kg/m3 . The probe predicted density within ± 2%. The sensor is installed in a nominal 5-cm-diameter (2-in.) pipe spool piece; the design pressure is 2.8 MPa (400 psi). To ensure operability during prolonged contact with radioactive waste, the probe wedge in contact with the slurry was selected to operate up to pH 14, and the probe components were radiation tested at exposures of 1×106 R.Copyright

Qualification of Three On-line Slurry Monitoring Devices for Application during Waste Retrieval Operations at DOE Sites

Millions of gallons of radioactive liquid and sludge wastes must be retrieved from underground storage tanks at the U.S. Department of Energy sites to be staged and transferred to treatment facilities and processed into final waste forms. Retrieval operations involve mixing solid and liquid wastes to create slurries that can be transported via underground pipelines to specified locations for treatment or disposal. A major concern during the transfer operations is plugging of the transfer lines. Blocked transfer lines could significantly escalate the remediation costs both in terms of pipeline replacement costs and costs of maintenance of inactive facilities and operating personnel.

Surface Tension Estimates for Droplet Formation in Slurries with Low Concentrations of Hydrophobic Particles, Polymer Flocculants or Surface-Active Contaminants

In support of the K-Basin project, Pacific Northwest National Laboratory (PNNL) was requested to evaluate the appropriate surface tension value to use in models predicting the formation of droplets from spray leaks of K-Basin slurries. The specific issue was whether it was more appropriate to use the surface tension of pure water in model predictions for all plausible spray leaks or to use a lower value. The surface tension of K-Basin slurries is potentially affected not only by particles but by low concentrations of nonionic polyacrylamide flocculant and perhaps by contaminants with surfactant properties, which could decrease the surface tension below that of water. A lower surface tension value typically results in smaller droplets being formed with a larger fraction of droplets in the respirable size range, so using the higher surface tension value of pure water is not conservative and thus needs a strong technical basis.

Exploration mission enhancements possible with power beaming

A key factor in the exploration and development of the space frontier is the availability of energy where and when it is needed. Currently all space satellites and platforms include self‐contained power systems that supply the energy necessary to accomplish mission objectives. An alternative approach is to couple advanced high power systems with energy beam transmitters and energy receivers to form an infrastructure of a space power utility where a central power system provides power to multiple users. Major space activities, such as low Earth orbit space commercialization and the colonization of the Moon or Mars, would benefit significantly from a central power generation and transmission system. This paper describes the power‐beaming concept and system components as applied to space power generation and distribution in support of the Space Exploration Initiative. Beam‐power scenarios are discussed including commonality of systems and hardware with cargo transport vehicles, power beaming from orbit to st...