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Design of Soil Vapor Extraction Systems
Published in Jimmy H.C. Wong, Chin Hong Lim, Greg L. Nolen, Design of Remediation Systems, 2020
Jimmy H.C. Wong, Chin Hong Lim, Greg L. Nolen
In calculating the breakthrough pressure that is required, the hydrostatic head (water column in the well above the screen) is a good first assumption. Unless highly permeable soil formations are encountered, the breakthrough pressure will usually be some multiple of the hydrostatic head. The hydrostatic head is determined by measuring from the water table down to the top of the slotted section of the sparge well. Depending on the type of soil, additional pressure will be required to overcome capillary effects due to capillary rise within the aquifer. This value is generally ignored when determining the hydrostatic head.
Concepts of a Hydropower Project
Published in Suchintya Kumar Sur, A Practical Guide to Construction of Hydropower Facilities, 2019
Hydro is a word of Greek origin which means water, and hydropower is the energy contained in water. It is generated by the water in motion and a combination of head and flow. The river water flows from the source at higher elevations to lower elevations by gravitational force, and it loses its potential energy to gain kinetic energy. The difference in water level is called hydrostatic head, which is capable of helping water to flow downstream, and in many projects; the requisite head created by building an impervious barrier across the river is called a dam, which enables the creation of a water reservoir in the upstream side of the river. Hydropower engineering taps this energy of water (potential), which is converted into kinetic energy due to gravity, for subsequently onward transmission to mechanical energy and finally into electrical energy.
Bubble column photobioreactor for Chlorella pyrenoidosa cultivation and validating gas hold up and volumetric mass transfer coefficient
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2023
Mubarak M., Shaija A., Prashanth P.
Mixing of the culture is achieved by sparging air in the culture using the spargers, which determines the gas hold up profiles and volumetric mass transfer coefficient of the microalgae culture and hence the performance of the bubble column photobioreactor. If the H/D ratio is very low, sparger design becomes crucial for the complete design of the photobioreactor. Since, improper design results in weeping causing a large pressure drops and non-uniformity in sparging. During non-weeping condition the kinetic energy of air entering the gas chamber balances the hydrostatic head over the sparger and the surface tension forces.
A shortcut model to estimate oil production rate in VAPEX process
Published in Petroleum Science and Technology, 2019
Saeid Nadriyan, Seyednooroldin Hosseini
VAPEX can be divided into three time steps throughout the process. In the first step, the vapor chamber of the VAPEX needs to form. When the vapor reaches the top of the reservoir, the second step starts. In this step, the vapor chamber expands sideways. The oil flow rate during this step is roughly constant. This holds the huge part of the oil recovery process. When the vapor chamber touches the outer boundary of the reservoir, the final step starts. In this step, the hydrostatic head of gravity drainage decreases with time.
Long-term operation of anaerobic digestion of food waste under simplified conditions: effect on reactor performance
Published in Environmental Technology, 2023
Tiago B. Ferreira, Fabiana Passos, Cláudio Leite de Souza
Whereas Q is recirculation rate, d is pipe and nozzle diameter (50 mm), ρL is liquid density (1001.7 kg m−3 for ∼12% TS [33]), g is gravity, H is hydrostatic head of liquid (2.5 m).