Effects of Operating Parameters on the Efficacy of Engineered Water Nanostructures (EWNS) in Inactivating Escherichia coli on Stainless-Steel Surfaces

2021 ◽  
Vol 64 (6) ◽  
pp. 1913-1920
Author(s):  
Yuchen Si ◽  
Yingjie Yang ◽  
Myra Martel ◽  
Brooke Thompson ◽  
Bernardo Predicala ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Flow Rate ◽  
Liquid Flow ◽  
Applied Voltage ◽  
Counter Electrode ◽  
Liquid Flow Rate ◽  
Operating Conditions ◽  
Stainless Steel Surface ◽  
Bacterial Concentration ◽  
E Coli

HighlightsThe efficacy of EWNS to disinfect surfaces was assessed at a bacterial concentration similar to pig barns.Liquid pH, liquid conductivity, and applied voltage were found to directly affect the efficacy of EWNS.The efficacy increased as liquid flow rate and distance between needle tip and counter electrode decreased.An E. coli reduction of 3.0 log was achieved on a stainless-steel surface after 15 min exposure to EWNS.Abstract. Several studies have shown the potential of engineered water nanostructures (EWNS) generated using a capillary electrospray system to inactivate foodborne bacteria; however, there is a lack of data on EWNS performance in inactivating microbes in livestock facilities. Thus, this laboratory-scale study investigated the effects of operating conditions on the efficacy of EWNS in inactivating Escherichia coli (E. coli) on coupons made of stainless steel, a common surface material in pig barns, at a bacterial concentration similar to levels found on pig barn surfaces. The electrospray module was composed of a capillary needle that was connected to a high-voltage power supply. The efficacy of the technology in inactivating E. coli was assessed with various operating parameters (i.e., applied voltage, distance between needle tip and counter electrode, and liquid flow rate, pH, and conductivity). The efficacy of the EWNS was found to be directly related to the liquid pH, liquid conductivity, and applied voltage, but inversely related to the liquid flow rate and distance between the needle tip and counter electrode. An E. coli reduction of 3.0 log was obtained after 15 min exposure to EWNS under the following operating conditions: liquid flow rate of 1 µL min-1, pH of 12, liquid conductivity of 14.72 mS cm-1, 2 cm distance between the needle tip and counter electrode, and -7.6 kV applied voltage. The results of this study can serve as an initial basis for the application of EWNS on surfaces in a real barn environment, where the presence of other factors, such as gases, dust, and other organic matter and microbial species, must be taken into account. Keywords: Electrospray, Engineered water nanostructures, E. coli, Stainless-steel surface, Surface decontamination.

Absorption and Mass Transfer of CO2 in Monoethanolamine Solution

2016 ◽  
Vol 859 ◽  
pp. 153-157
Author(s):  
Pao Chi Chen ◽  
Sheng Zhong Lin
Keyword(s):  
Mass Transfer ◽  
Flow Rate ◽  
Liquid Flow ◽  
Gas Flow ◽  
Liquid Flow Rate ◽  
Bubble Column ◽  
Operating Conditions ◽  
Gas Flow Rate ◽  
Constant Ph ◽  
Gas Liquid Flow

This work uses a continuous bubble-column scrubber for the absorption of CO2 with a 5M MEA solution under a constant pH environment to explore the effect of the pH of the solution and gas-flow rate (Qg) on the removal efficiency (E), absorption rate (RA), overall mass-transfer coefficient (KGa), liquid flow rate (QL), gas-liquid flow ratio (γ), and scrubbing factors (φ). From the outlet CO2 concentration with a two-film model, E, RA, KGa, QL, γ, and φ can be simultaneously determined at the steady state. Depending on the operating conditions, the results show that E (80-97%), RA(2.91x10-4-10.0x10-4mol/s-L), KGa (0.09-0.48 1/s), QL(8.74-230.8mL/min), γ (0.19-5.39), and φ (0.031-0.74 mol/mol-L) are found to be comparable with other solvents. In addition, RA, KGa, E, and QL have been used to correlate with pH and Qg, respectively, with the results further explained.

A Novel Gas-Assist Atomizer for Power Stations

2008 ◽  
Author(s):  
M. P. Levitsky ◽  
E. Korin ◽  
J. Haddad ◽  
S. P. Levitsky ◽  
Y. Levy ◽  
...  
Keyword(s):  
Flow Rate ◽  
Liquid Flow ◽  
Liquid Flow Rate ◽  
Field Tests ◽  
Operating Conditions ◽  
Spray Angle ◽  
Scattering Method ◽  
Water Mixture ◽  
Power Station ◽  
Liquid Atomization

A novel high flow rate gas-assist atomizer for liquid atomization was developed. The method of liquid supply in the zone of maximal air velocity is used. It is shown that it is possible to achieve fine atomization as the relative velocity between gas and liquid is very high. However actual sprays have droplets with larger size due to the rapid decrease of the difference between air and liquid velocities. So droplets disintegrate mainly due to the turbulent velocity fluctuations of the air flow. The experimental study included two stages: laboratory tests and field tests inside a full size boiler of a 220 MW power station. At the first stage, several atomizer modifications were tested using water and compressed air. Droplet size was measured by a special Laser Light Scattering method. Liquid flow rate was equal to 3500 kg/hr. The liquid atomization quality at each cross-section of the spray was estimated by measuring the liquid-droplets sizes at several stations across the spray. The tests were carried out for two distances, 30 and 40 cm, downstream of the nozzle. The tests show that for the proposed atomizer droplets SMD was reduced from 135 to 67 microns. Droplets SMD maintains constant value when liquid flow rate is reduced by 50%. The spray angle was kept as in a standard atomizer and equal to 110 degrees under all operating conditions. It was found that to obtain this angle, the pressure downstream of the nozzle core should be atmospheric. The atomizer with the best performances was selected for the field tests. It was assumed that the atomizer which shows the best results for air-water mixture would be superior also for steam-fuel mixture. Field tests of the atomizer within the burner of an actual power station in Israel (boiler by Babcock Borsig Company), demonstrated a significant reduction in NOx content, from 540 to 270 ppmv as well as better service conditions.

Investigation of Optimum Applied Voltage, Liquid Flow Pressure, and Spraying Height for Pesticide Application by Induction Charging

2019 ◽  
Vol 35 (5) ◽  
pp. 795-804 ◽  
Author(s):  
Samuel Appah ◽  
Weidong Jia ◽  
Mingxiong Ou ◽  
Pei Wang ◽  
Chen Gong
Keyword(s):  
Flow Rate ◽  
Liquid Flow ◽  
Applied Voltage ◽  
Liquid Flow Rate ◽  
Plant Protection ◽  
Pesticide Application ◽  
Optimum Parameters ◽  
Spray Droplets ◽  
Droplet Sizes ◽  
Flow Pressure

Abstract. Superposition of charges to pesticide spray droplets by electrostatic induction principle plays an important role in plant protection. It influences spray droplets characteristics, deposition and wraparound effect on leaf surfaces. Hence, an adoption of optimum parameters combination will improve spraying effectiveness to reduce pesticide wastage and environmental pollution. This article investigated the effect of 0-12 kV applied voltages, 2-4 bar liquid flow pressures, and 20-60 cm spraying height regimes on spray chargeability, droplet sizes, spray swath, and droplets deposition while all other parameters were kept constant. The combined parameters of 12 kV applied voltage, 4 bar liquid flow pressure, and 60 cm spraying height produced maximum charged spray swath (1.98 m) and fine particulate droplet sizes (48.91 µm). However, applied voltage of 12 kV, liquid flow pressure of 4 bar at spraying height of 20 cm yielded maximum chargeability of -1.95×10-3 mC kg-1. Since spraying height influences the extent of pesticide spray coverage, a boom height of 60 cm is suitable for deposition in electrostatic pesticide application at 12 kV charging voltage and 4 bar liquid flow rate. The operation of combined optimum parameters took reference from a uniform plant height surface during spraying. Hitherto, the study would help farmers to select suitable electrostatic spraying parameters for pesticide application in plant protection. Keywords: Applied voltage, Charge-mass ratio, Droplet sizes, Liquid flow rate, Spray pressure, Spray swath.

Investigation of the Motion of Bubbles in a Centrifugal Pump Impeller

2018 ◽  
Vol 141 (3) ◽  
Author(s):  
Henrique Stel ◽  
Edgar M. Ofuchi ◽  
Renzo H. G. Sabino ◽  
Felipe C. Ancajima ◽  
Dalton Bertoldi ◽  
...  
Keyword(s):  
Centrifugal Pump ◽  
Flow Rate ◽  
Liquid Flow ◽  
Liquid Flow Rate ◽  
Operating Conditions ◽  
Impeller Speed ◽  
Pump Impeller ◽  
Pump Performance ◽  
Liquid Flows ◽  
Centrifugal Pump Impeller

Centrifugal pumps operate below their nominal capacity when handling gas–liquid flows. This problem is sensitive to many variables, such as the impeller speed and the liquid flow rate. Several works evaluate the effect of operating conditions in the pump performance, but few bring information about the associated gas–liquid flow dynamics. Studying the gas phase behavior, however, can help understanding why the pump performance is degraded depending on the operating condition. In this context, this paper presents a numerical and experimental study of the motion of bubbles in a centrifugal pump impeller. The casing and the impeller of a commercial pump were replaced by transparent components to allow evaluating the bubbles' trajectories through high-speed photography. The bubble motion was also evaluated with a numerical particle-tracking method. A good agreement between both approaches was found. The numerical model is explored to evaluate how the bubble trajectories are affected by variables such as the bubble diameter and the liquid flow rate. Results show that the displacement of bubbles in the impeller is hindered by an increase of their diameter and impeller speed but facilitated by an increase of the liquid flow rate. A force analysis to support understanding the pattern of the bubble trajectories was provided. This analysis should enlighten the readers about the dynamics leading to bubble coalescence inside an impeller channel, which is the main reason behind the performance degradation that pumps experience when operating with gas–liquid flows.

Effects of Operating Conditions on Thin Film Deposition Performance in Air Atomizing Spray Pyrolysis

2010 ◽  
Author(s):  
Changxue Xu ◽  
Yong Huang ◽  
Yafu Lin
Keyword(s):  
Thin Film ◽  
Surface Roughness ◽  
Flow Rate ◽  
Liquid Flow ◽  
Liquid Flow Rate ◽  
Thin Film Deposition ◽  
Air Gap ◽  
Film Deposition ◽  
Operating Conditions ◽  
Air Pressure

Thin films have been finding more and more applications in electronics, optical devices, and energy conversion and storage devices, to name a few. As one of the most promising thin film deposition techniques, air atomizing spray pyrolysis, which uses compressed air to disrupt the liquid stream into droplets, has been favored in scientific and engineering communities. However, the effects of operating conditions such as liquid flow rate, atomizing air pressure, fan air pressure, and air gap on the geometric properties of deposited thin film are still not systematically studied. The objective of this study is to experimentally investigate the effects of air spraying operating conditions on the surface roughness and thickness of deposited zinc oxide (ZnO) thin film. It is found 1) The surface roughness increases with the liquid flow rate, but decreases with the atomizing air pressure, fan air pressure, and air gap; 2) The surface roughness decreases along both the X and Y directions under any given operating condition; 3) The thickness increases with the liquid flow rate and the atomizing air pressure, but decreases with the fan air pressure and the air gap; and 4) The thickness generally changes differently along the X and Y directions. Along the X direction, it decreases monotonically; however, along the Y direction, it increases first then decreases as in a saddle shape. While ZnO film deposition is studied, it is expected that the above conclusions may be applicable in air spraying other materials.

scholarly journals Validation of the Molar Flow Rates of Oil and Gas in Three-Phase Separators Using Aspen Hysys

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 327
Author(s):  
Adeola Grace Olugbenga ◽  
Najah M. Al-Mhanna ◽  
Muibat Diekola Yahya ◽  
Eyitayo Amos Afolabi ◽  
Martins Kolade Ola
Keyword(s):  
Flow Rate ◽  
Liquid Flow ◽  
Oil And Gas ◽  
Liquid Flow Rate ◽  
Operating Conditions ◽  
Feed Stream ◽  
Aspen Hysys ◽  
Reservoir Fluid ◽  
Three Phase ◽  
Phase Separator

A three-phase separator is the first vessel encountered by well fluids. The application of separators has been of great value to the oil and gas industry. In order to generate the gas phase envelope that is applicable to the study of reservoir fluid and the selection of optimum operating conditions of separators, this research utilizes a specified reservoir fluid stream to simulate a three-phase separator executed in Aspen HYSYS. Subsequently, a comparative study of the effects of specified inlet operating conditions on the output of gas and oil streams was carried out. The results show that changing the inlet pressure of the separator from 1000 to 8000 kPa reduces the gas outlet flow from 1213 to 908.6 kg mol/h, while it increases the liquid flow rate from 374 to 838.0 kg mole/h. By changing the temperature of the separator feed stream from 13 to 83 °C, the gas outlet stream was raised from 707.4 to 1111 kg mol/h, while the liquid flow rate dropped from 1037.0 to 646.1 kg mol/h. It was observed that the concentration of the outlet methane product is not affected by changing the flow rate of the feed stream at a specific pressure and temperature. Therefore, the thermodynamic property method is appropriate to simulate the separation of reservoir fluids which was achieved by selecting the Peng–Robinson (PR) model. The operating conditions of the separator were at 8000 kPa and 43 °C, which lies right on the dew point line. This is comparable to similar work on CHEMCAD which was in turn validated by plant data. Thus, the gas flow rate and the oil flow rate were dependent on pressure and temperature conditions of the plant.

Absorption of oxygen into solutions of polymers

1986 ◽  
Vol 51 (10) ◽  
pp. 2127-2134 ◽  
Author(s):  
František Potůček ◽  
Jiří Stejskal
Keyword(s):  
Mass Transfer ◽  
Aqueous Solutions ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Flow Rate ◽  
Liquid Flow ◽  
Flow Curve ◽  
Liquid Flow Rate ◽  
Polymer Concentration ◽  
Newtonian Liquids

Absorption of oxygen into water and aqueous solutions of poly(acrylamides) was studied in an absorber with a wetted sphere. The effects of changes in the liquid flow rate and the polymer concentration on the liquid side mass transfer coefficient were examined. The results are expressed by correlations between dimensionless criteria modified for non-Newtonian liquids whose flow curve can be described by the Ostwald-de Waele model.

scholarly journals Effects of water salinity on the foam dynamics for EOR application

2021 ◽  
Author(s):  
Svetlana Rudyk ◽  
Sami Al-Khamisi ◽  
Yahya Al-Wahaibi
Keyword(s):  
Flow Rate ◽  
Liquid Flow ◽  
Apparent Viscosity ◽  
Liquid Flow Rate ◽  
Salinity Range ◽  
Porous System ◽  
Foam Formation ◽  
Total Flow ◽  
Total Flow Rate ◽  
Foam Flow

AbstractFactors limiting foam injection for EOR application are exceptionally low rock permeability and exceedingly high salinity of the formation water. In this regard, foam formation using internal olefin sulfonate is investigated over a wide salinity range (1, 5, 8, 10, and 12% NaCl) through 10 mD limestone. The relationships between pressure drop (dP), apparent viscosity, liquid flow rate, total flow rate, salinity, foam texture, and length of foam drops at the outlet used as an indicator of viscosity are studied. Foaming is observed up to 12% NaCl, compared to a maximum of 8% NaCl in similar core-flooding experiments with 50 mD limestone and 255 mD sandstone. Thus, the salinity limit of foam formation has increased significantly due to the low permeability, which can be explained by the fact that the narrow porous system acts like a membrane with smaller holes. Compared to the increasing dP reported for highly permeable rocks, dP linearly decreases in almost the entire range of gas fraction (fg) at 1–10% NaCl. As fg increases, dP at higher total flow rate is higher at all salinities, but the magnitude of dP controls the dependence of apparent viscosity on total flow rate. Low dP is measured at 1% and 10% NaCl, and high dP is measured at 5, 8, and 12% NaCl. In the case of low dP, the apparent viscosity is higher at higher total flow rate with increasing gas fraction, but similar at two total flow rates with increasing liquid flow rate. In the case of high dP, the apparent viscosity is higher at lower total flow rate, both with an increase in the gas fraction and with an increase in the liquid flow rate. A linear correlation is found between dP or apparent viscosity and liquid flow rate, which defines it as a governing factor of foam flow and can be considered when modeling foam flow.

Numerical Simulation of Gas-Liquid Two-Phase Flows on Wetted Walls

2010 ◽  
Author(s):  
Yoshiyuki Iso ◽  
Xi Chen
Keyword(s):  
Numerical Simulation ◽  
Flow Rate ◽  
Liquid Flow ◽  
Film Flow ◽  
Liquid Flow Rate ◽  
Flow Transition ◽  
Wall Surface ◽  
Two Phase ◽  
Wall Flows ◽  
Rivulet Flow

Gas-liquid two-phase flows on the wall like liquid film flows, which are the so-called wetted wall flows, are observed in many industrial processes such as absorption, desorption, distillation and others. For the optimum design of packed columns widely used in those kind of processes, the accurate predictions of the details on the wetted wall flow behavior in packing elements are important, especially in order to enhance the mass transfer between the gas and liquid and to prevent flooding and channeling of the liquid flow. The present study focused on the effects of the change of liquid flow rate and the wall surface texture treatments on the characteristics of wetted wall flows which have the drastic flow transition between the film flow and rivulet flow. In this paper, the three-dimensional gas-liquid two-phase flow simulation by using the volume of fluid (VOF) model is applied into wetted wall flows. Firstly, as one of new interesting findings in this paper, present results showed that the hysteresis of the flow transition between the film flow and rivulet flow arose against the increasing or decreasing stages of the liquid flow rate. It was supposed that this transition phenomenon depends on the history of flow pattern as the change of curvature of interphase surface which leads to the surface tension. Additionally, the applicability and accuracy of the present numerical simulation were validated by using the existing experimental and theoretical studies with smooth wall surface. Secondary, referring to the texture geometry used in an industrial packing element, the present simulations showed that surface texture treatments added on the wall can improve the prevention of liquid channeling and can increase the wetted area.

Sign in / Sign up

Export Citation Format

Share Document