Rearrangement of membrane elements in the pressure vessels for optimum utilization of reverse osmosis process

2011 ◽  
Vol 89 (1) ◽  
pp. 48-54 ◽  
Author(s):  
S.S. Madaeni ◽  
M. Afshar ◽  
N. Jaafarzadeh ◽  
F. Tarkian ◽  
K. Ghasemipanah
Keyword(s):  
Reverse Osmosis ◽  
Pressure Vessels ◽  
Optimum Utilization

scholarly journals Performance Analysis of a Full-Scale Desalination Plant with Reverse Osmosis Membranes for Irrigation

Membranes ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 774
Author(s):  
Federico Leon ◽  
Alejandro Ramos
Keyword(s):  
Reverse Osmosis ◽  
Specific Energy Consumption ◽  
Production Capacity ◽  
Pressure Vessels ◽  
Full Scale ◽  
Operating Data ◽  
Term Operation ◽  
Desalination Plant ◽  
Pre Treatment

Reverse osmosis (RO) is the most widely used technology for seawater desalination purposes. The long-term operating data of full-scale plants is key to analyse their performance under real conditions. The studied seawater reverse osmosis (SWRO) desalination plant had a production capacity of 5000 m3/d for irrigation purposes. The operating data such as conductivities flows, and pressures were collected for around 27,000 h for 4 years. The plant had sand and cartridge filters without chemical dosing in the pre-treatment stage, a RO system with one stage, 56 pressure vessels, seven RO membrane elements per pressure vessel and a Pelton turbine as energy recovery device. The operating data allowed to calculate the average water and salt permeability coefficients (A and B) of the membrane as well as the specific energy consumption (SEC) along the operating period. The calculation of the average A in long-term operation allowed to fit the parameters of three different models used to predict the mentioned parameter. The results showed a 30% decrease of A, parameter B increase around 70%. The SEC was between 3.75 and 4.25 kWh/m3. The three models fitted quite well to the experimental data with standard deviations between 0.0011 and 0.0015.

scholarly journals Performance Assessment of SWRO Spiral-Wound Membrane Modules with Different Feed Spacer Dimensions

Processes ◽  
2020 ◽  
Vol 8 (6) ◽  
pp. 692 ◽  
Author(s):  
A. Ruiz-García ◽  
I. Nuez
Keyword(s):  
Reverse Osmosis ◽  
Pressure Vessels ◽  
Operating Conditions ◽  
Solute Permeability ◽  
Permeability Coefficients ◽  
Water Permeability Coefficient ◽  
Seawater Reverse Osmosis ◽  
Membrane Modules ◽  
The Impact ◽  
Spiral Wound

Reverse osmosis is the leading process in seawater desalination. However, it is still an energy intensive technology. Feed spacer geometry design is a key factor in reverse osmosis spiral wound membrane module performance. Correlations obtained from experimental work and computational fluid dynamics modeling were used in a computational tool to simulate the impact of different feed spacer geometries in seawater reverse osmosis spiral wound membrane modules with different permeability coefficients in pressure vessels with 6, 7 and 8 elements. The aim of this work was to carry out a comparative analysis of the effect of different feed spacer geometries in combination with the water and solute permeability coefficients on seawater reverse osmosis spiral wound membrane modules performance. The results showed a higher impact of feed spacer geometries in the membrane with the highest production (highest water permeability coefficient). It was also found that the impact of feed spacer geometry increased with the number of spiral wound membrane modules in series in the pressure vessel. Installation of different feed spacer geometries in reverse osmosis membranes depending on the operating conditions could improve the performance of seawater reverse osmosis systems in terms of energy consumption and permeate quality.

SANITATION STUDIES OF A REVERSE OSMOSIS UNIT USED FOR CONCENTRATION OF MAPLE SAP

1970 ◽  
Vol 33 (8) ◽  
pp. 326-329 ◽  
Author(s):  
J. C. Kissinger
Keyword(s):  
Reverse Osmosis ◽  
Chlorine Dioxide ◽  
Pressure Vessels ◽  
Industrial Scale ◽  
Sanitary Condition ◽  
Plate Counts ◽  
Membrane Modules ◽  
Maple Sap ◽  
Reverse Osmosis Unit ◽  
Unit Pressure

Sanitation studies of an industrial-scale reverse osmosis unit used for the concentration of maple sap are discussed. Bacterial plate counts of the concentrate and permeate effluent streams declined steadily during the initial 10–12 hr of operation, followed by respective increases in count from 2.8 × 104 per ml (12 hr) to 2.0 × 105 per ml (36 hr) and from 3.3 × 103 per ml (12 hr) to 2.4 × 104 per ml (36 hr). Membrane modules were maintained in good sanitary condition in the reverse osmosis unit pressure vessels for as long as one month when the modules were kept in contact with an acidified chlorine dioxide sanitizer.

Foulant characterization and distribution in spiral wound reverse osmosis membranes from different pressure vessels

Desalination ◽  
2015 ◽  
Vol 370 ◽  
pp. 44-52 ◽  
Author(s):  
Sung-Jo Kim ◽  
Byung Soo Oh ◽  
Hye-Weon Yu ◽  
Lan Hee Kim ◽  
Chang-Min Kim ◽  
...  
Keyword(s):  
Reverse Osmosis ◽  
Pressure Vessels ◽  
Reverse Osmosis Membranes ◽  
Spiral Wound

1250-kilovolt scanning transmission electron microscope

1984 ◽  
Vol 42 ◽  
pp. 624-625
Author(s):  
T. Imura ◽  
S. Maruse ◽  
K. Mihama ◽  
M. Iseki ◽  
M. Hibino ◽  
...  
Keyword(s):  
High Voltage ◽  
Electron Probe ◽  
Scanning Transmission Electron Microscope ◽  
Pressure Vessels ◽  
Practical Applications ◽  
Voltage Generator ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
New Applications ◽  
High Voltage Generator

Ultra high voltage STEM has many inherent technical advantages over CTEM. These advantages include better signal detectability and signal processing capability. It is hoped that it will explore some new applications which were previously not possible. Conventional STEM (including CTEM with STEM attachment), however, has been unable to provide these inherent advantages due to insufficient performance and engineering problems. Recently we have developed a new 1250 kV STEM and completed installation at Nagoya University in Japan. It has been designed to break through conventional engineering limitations and bring about theoretical advantage in practical applications.In the design of this instrument, we exercised maximum care in providing a stable electron probe. A high voltage generator and an accelerator are housed in two separate pressure vessels and they are connected with a high voltage resistor cable.(Fig. 1) This design minimized induction generated from the high voltage generator, which is a high frequency Cockcroft-Walton type, being transmitted to the electron probe.

Cellulose Acetate Reverse Osmosis Membrane Structure

1972 ◽  
Vol 30 ◽  
pp. 528-529
Author(s):  
H. K. Plummer ◽  
E. Eichen ◽  
C. D. Melvin
Keyword(s):  
Cellulose Acetate ◽  
Reverse Osmosis ◽  
Membrane Structure ◽  
Freeze Drying ◽  
Dense Layer ◽  
Water Removal ◽  
Reverse Osmosis Membrane ◽  
Correct Interpretation ◽  
Electron Image ◽  
Scanning Electron

Much of the work reported in the literature on cellulose acetate reverse osmosis membranes has raised new and important questions with regard to the dense or “active” layer of these membranes. Several thickness values and structures have been attributed to the dense layer. To ensure the correct interpretation of the cellulose acetate structure thirteen different preparative techniques have been used in this investigation. These thirteen methods included various combinations of water substitution, freeze drying, freeze sectioning, fracturing, embedding, and microtomy techniques with both transmission and scanning electron microscope observations.It was observed that several factors can cause a distortion of the structure during sample preparation. The most obvious problem of water removal can cause swelling, shrinking, and folds. Improper removal of embedding materials, when used, can cause a loss of electron image contrast and, or structure which could hinder interpretation.

Probabilistic evaluation of detection capability of eddy current testing to inspect pitting on a stainless steel clad using multiple signal features

2020 ◽  
Vol 64 (1-4) ◽  
pp. 47-55
Author(s):  
Takuma Tomizawa ◽  
Haicheng Song ◽  
Noritaka Yusa
Keyword(s):  
Stainless Steel ◽  
Eddy Current ◽  
Pressure Vessels ◽  
Eddy Current Testing ◽  
Probability Of Detection ◽  
Current Testing ◽  
Multiple Signal ◽  
Signal Features ◽  
Inner Surface ◽  
Drill Holes

This study proposes a probability of detection (POD) model to quantitatively evaluate the capability of eddy current testing to detect flaws on the inner surface of pressure vessels cladded by stainless steel and in the presence of high noise level. Welded plate samples with drill holes were prepared to simulate corrosion that typically appears on the inner surface of large-scale pressure vessels. The signals generated by the drill holes and the noise caused by the weld were examined using eddy current testing. A hit/miss-based POD model with multiple flaw parameters and multiple signal features was proposed to analyze the measured signals. It is shown that the proposed model is able to more reasonably characterize the detectability of eddy current signals compared to conventional models that consider a single signal feature.

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