An Impedance Cross Correlation (ICC) Device For Measuring Solids Velocity And Volume Fraction Profiles In Solid-Water Flows

Multiphase flow is the simultaneous flow of two or more phases, in direct contact, in a given system. It is important in many fields of chemical and process engineering and in the oil industry, e.g. in production wells and in sub-sea pipelines. The behavior of the flow will depend on the properties of the constituents, the flows and the geometry of the system. Upward inclined solids-liquid flows are sometimes encountered in the process industries for example in water treatment processes and in oil well drilling operations. Measurements of the local solids volume fraction distribution and the local axial solid velocity distribution are important, for example, in measuring the solids volumetric flow rate. This study presents a non-intrusive Impedance Cross- Correlation (ICC) device to measure the local solids volume fraction distribution and the local axial solids velocity distribution in upward inclined solids-water flows in which these distributions are highly non-uniform. The ICC device comprises a non-conductive pipe section of 80mm internal diameter fitted with two arrays of electrodes at planes, A and B, separated by an axial distance of 50mm. At each plane, eight electrodes are equispaced over the internal circumference of the pipe. A control system consisting of a microcontroller and analogue switches is used such that, for planes A and B, any of the eight electrodes can be configured as an ‘excitation electrode’ (V+), a ‘virtual earth measurement electrode’ (ve) or an ‘earth electrode’ (E) so that different regions of the flow cross section can be interrogated. Conductance signals from planes A and B are then cross correlated to yield the solids velocity in the region of flow under interrogation. Experiments were carried out in water-solids flows in a flow loop with an 80 mm inner diameter, 1.68m long Perspex test section which was inclined at 30o to the vertical. The most significant experimental result is that, at the upper side of the inclined pipe, the measured solids velocity is positive (i.e. in the upward direction), whilst at the lower side of the inclined pipe the measured local axial solids velocity is negative (i.e. in the downward direction). This shows quantitative agreement with previous work carried out using intrusive local probes to measure the solids velocity profile. The study also shows qualitative agreement with high speed film of the flow. It is believed that this method of velocity profile measurement is much simpler to implement than dualplane electrical resistance tomography (ERT)

Non-invasive velocity and volume fraction profile measurement in multiphase flows

Multiphase flow is the simultaneous flow of two or more phases, in direct contact, and is important in the oil industry, e.g. in production wells, in sub-sea pipelines and during the drilling of wells. The behaviour of the flow will depend on the properties of the constituent phases, the flow velocities and volume fractions of the phases and the geometry of the system. In solids-in-liquid flows, measurement of the local solids volume fraction distribution and the local axial solids velocity distribution in the flow cross section is important for many reasons including health and safety and economic reasons, particularly in oil well drilling operations. However upward inclined solidsliquid flows which are frequently encountered during oil well drilling operations are not well understood. Inclined solids-liquid flows result in non- uniform profiles of the solids volume fraction and axial solids velocity in the flow cross- section. In order to measure the solids volumetric flow rate in these situations it is necessary to measure the distributions of the local solids volume fraction and the local axial solids velocity and then to integrate the product of these local properties in the flow cross section. This thesis describes the development of a non-intrusive Impedance Cross-Correlation (ICC) device to measure the local solids volume fraction distribution and the local solids axial solids velocity distribution in upward inclined solids-water flows in which these distributions are highly non-uniform. The ICC device comprises a non-conductive pipe section of 80mm internal diameter fitted with two arrays of electrodes, denoted „array A‟ and „array B‟, separated by an axial distance of 50mm. At each array, eight electrodes are equispaced over the internal circumference of the pipe. A control system consisting of a microcontroller and analogue switches is used such that, for arrays A and B, any of the eight electrodes can be configured as an "excitation electrode" (V+), a "virtual earth measurement electrode" (Ve) or an "earth electrode" (E) thus enabling the local mixture conductance in different regions of the flow cross-section to be measured and thereby allowing the local solids volume fraction in each region to be deduced. The conductance signals from arrays A and B are also cross-correlated to yield the local solids axial velocity in the regions of flow under interrogation. A number of experiments were carried out in solids-in-water flows in a flow loop with an 80 mm inner diameter, 1.68m long Perspex test section which was inclined at three different inclination angle to the vertical ( o 0 , o 15 and o 30 ). The obtained results show good quantitative agreement with previous work carried out using intrusive local probes. Integration of the flow profiles in the cross section also yielded excellent quantitative agreement with reference measurements of the mean solids volume fraction, the mean solids velocity and the solids volumetric flow rate. Furthermore, this study also showed good qualitative agreement with high speed film of the flow. It is believed that the method of velocity and volume fraction profile measurement described in this thesis is much simpler to implement, more accurate and less expensive than the currently very popular technique of dual-plane Electrical Resistance Tomography (ERT). Finally, the thesis describes a mathematical model for predicting the axial velocity distribution of inclined solids-water flows using the solids volume fraction profiles measured by the ICC device. Good agreement was obtained between the predicted velocity profiles and the velocity profiles measured using the ICC device.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Al- jahiz Vision in Umayyad era

The study seeks to highlight the role played by the Al- jahiz in the presentation of historical novels about the Umayyads, these novels by Al- jahiz himself from the rest of history, literature and other books, the study also explores the factors that contributed to the entry of the Umayyad dynasty in particular conflicts in the last years of the Umayyad state. The study addresses to highlight the role of Al- jahiz in writing the Umayyad state and how it was to the closeness of the Abbasid Caliphate reflection on his writings about the Umayyad dynasty. The study also explores the approach that was followed by most of the history book and Al- jahiz position of many of the writings and novels when streamlines and analyzes and be critic. The study is based on the historical method and descriptive analytical approach in the presentation and discussion of the results through analysis of previous studies, and research will be added due to the lack of scientific research that dealt with the history of the Umayyad dynasty through literature

A flowmeter for measuring the dispersed phase velocity in multiphase flow with non-uniform velocity profiles

This study aims to introduce a new technique to measure the velocity distribution of the dispersed component of a vertical, upward, water continuous two-phase pipe flow. Here, it is proposed that measurements of the variation in the local conductance of the mixture can be cross correlated to determine the local velocity distribution of, for example, gas bubbles in water. The measurements were conducted by using arrays of axially separated conductance sensors. Each array contained eight electrodes distributed over the internal circumference of the pipe carrying the flow. The arrays, were mounted at a known distance from each other along the pipe. Within each array, individual electrodes could be configured as either ‘excitation’, ‘measurement’ or ‘earth’. By changing the electrode configuration of an array the electric field sensitivity distribution associated with the array could be altered, thus changing the region of the flow ‘interrogated’ by the system. By cross correlating the output signals from these arrays, in various combinations, the velocity of the dispersed phase can be obtained at different regions within the flow, thereby enabling the velocity profile of the dispersed phase to be measured. The sensitivity distribution associated with given electrode configurations has been investigated in a bench test. First the flow meter was filled with water, and then non-conducting rods were inserted into the flow meter at various spatial locations parallel to the pipe, and the resulting change in conductance measured. The sensitivity distribution has also been simulated using COMSOL software. Agreement between experiment and theory was close to 1 %

A flowmeter for measuring the dispersed phase velocity in multiphase flow with non-uniform velocity profile

This study aims to introduce a new technique to measure the velocity distribution of the dispersed component of a vertical, upward, water continuous two-phase pipe flow. Here, it is proposed that measurements of the variation in the local conductance of the mixture can be cross correlated to determine the local velocity distribution of, for example, gas bubbles in water. The measurements were conducted by using arrays of axially separated conductance sensors placed normal to the flow. Each array contained eight electrodes distributed over the internal circumference of the pipe carrying the flow. The arrays, were mounted at a known distance from each other along the pipe. Within each array, individual electrodes could be configured as either ‘excitation’, ‘measurement’ or ‘earth’. By changing the electrode configuration of an array the electric field sensitivity distribution associated with the array could be altered, thus changing the region of the flow ‘interrogated’ by the system. By cross correlating the output signals from these arrays, in various combinations, the velocity of the dispersed phase can be obtained at different regions within the flow, thereby enabling the velocity profile of the dispersed phase to be measured. The sensitivity distribution associated with given electrode configurations has been investigated in a bench test. First the flow meter was filled with water, and then nonconducting rods were inserted into the flow meter at various spatial locations parallel to the pipe, the resulting change in conductance was measured.. The sensitivity distribution has also been simulated using COMSOL software. Agreement between experiment and theory was close to 1 %

Non-invasive velocity and volume fraction profile measurement in multiphase flows

Multiphase flow is the simultaneous flow of two or more phases, in direct contact, and is important in the oil industry, e.g. in production wells, in sub-sea pipelines and during the drilling of wells. The behaviour of the flow will depend on the properties of the constituent phases, the flow velocities and volume fractions of the phases and the geometry of the system. In solids-in-liquid flows, measurement of the local solids volume fraction distribution and the local axial solids velocity distribution in the flow cross section is important for many reasons including health and safety and economic reasons, particularly in oil well drilling operations. However upward inclined solidsliquid flows which are frequently encountered during oil well drilling operations are not well understood. Inclined solids-liquid flows result in non- uniform profiles of the solids volume fraction and axial solids velocity in the flow cross- section. In order to measure the solids volumetric flow rate in these situations it is necessary to measure the distributions of the local solids volume fraction and the local axial solids velocity and then to integrate the product of these local properties in the flow cross section. This thesis describes the development of a non-intrusive Impedance Cross-Correlation (ICC) device to measure the local solids volume fraction distribution and the local solids axial solids velocity distribution in upward inclined solids-water flows in which these distributions are highly non-uniform. The ICC device comprises a non-conductive pipe section of 80mm internal diameter fitted with two arrays of electrodes, denoted „array A‟ and „array B‟, separated by an axial distance of 50mm. At each array, eight electrodes are equispaced over the internal circumference of the pipe. A control system consisting of a microcontroller and analogue switches is used such that, for arrays A and B, any of the eight electrodes can be configured as an "excitation electrode" (V+), a "virtual earth measurement electrode" (Ve) or an "earth electrode" (E) thus enabling the local mixture conductance in different regions of the flow cross-section to be measured and thereby allowing the local solids volume fraction in each region to be deduced. The conductance signals from arrays A and B are also cross-correlated to yield the local solids axial velocity in the regions of flow under interrogation. A number of experiments were carried out in solids-in-water flows in a flow loop with an 80 mm inner diameter, 1.68m long Perspex test section which was inclined at three different inclination angle to the vertical ( o 0 , o 15 and o 30 ). The obtained results show good quantitative agreement with previous work carried out using intrusive local probes. Integration of the flow profiles in the cross section also yielded excellent quantitative agreement with reference measurements of the mean solids volume fraction, the mean solids velocity and the solids volumetric flow rate. Furthermore, this study also showed good qualitative agreement with high speed film of the flow. It is believed that the method of velocity and volume fraction profile measurement described in this thesis is much simpler to implement, more accurate and less expensive than the currently very popular technique of dual-plane Electrical Resistance Tomography (ERT). Finally, the thesis describes a mathematical model for predicting the axial velocity distribution of inclined solids-water flows using the solids volume fraction profiles measured by the ICC device. Good agreement was obtained between the predicted velocity profiles and the velocity profiles measured using the ICC device

An Impedance Cross Correlation (ICC) device for measuring solids velocity and volume fraction profiles in solids-water flows

Multiphase flow is the simultaneous flow of two or more phases, in direct contact, in a given system. It is important in many fields of chemical and process engineering and in the oil industry, e.g. in production wells and in sub-sea pipelines. The behavior of the flow will depend on the properties of the constituents, the flows and the geometry of the system. Upward inclined solids-liquid flows are sometimes encountered in the process industries for example in water treatment processes and in oil well drilling operations. Measurements of the local solids volume fraction distribution and the local axial solid velocity distribution are important, for example, in measuring the solids volumetric flow rate. This paper presents a non-intrusive Impedance Cross-Correlation (ICC) device to measure the local solids volume fraction distribution and the local axial solids velocity distribution in upward inclined solids-water flows in which these distributions are highly non-uniform. The ICC device comprises a non-conductive pipe section of 80mm internal diameter fitted with two arrays of electrodes at planes, A and B, separated by an axial distance of 50mm. At each plane, eight electrodes are equispaced over the internal circumference of the pipe. A control system consisting of a microcontroller and analogue switches is used such that, for planes A and B, any of the eight electrodes can be configured as an ‘excitation electrode’ (V+), a ‘virtual earth measurement electrode’ (ve) or an ‘earth electrode’ (E) so that different regions of the flow cross section can be interrogated. Conductance signals from planes A and B are then cross correlated to yield the solids velocity in the region of flow under interrogation. Experiments were carried out in water-solids flows in a flow loop with an 80 mm inner diameter, 1.68m long Perspex test section which was inclined at o 30 to the vertical. The most significant experimental result is that, at the upper side of the inclined pipe, the measured solids velocity is positive (i.e. in the upward direction), whilst at the lower side of the inclined pipe the measured local axial solids velocity is negative (i.e. in the downward direction). This shows quantitative agreement with previous work carried out using intrusive local probes to measure the solids velocity profile. The study also shows qualitative agreement with high speed film of the flow. It is believed that this method of velocity profile measurement is much simpler to implement than dual-plane electrical resistance tomography (ERT)