Search results

Excessive liquid carryover in T-junction presents a serious operational issue in offshore production platform. Slug flow and diameter ratio of T-junction are considered as two major factors causing liquid carryover. Regular and reduced T-junction are being used as partial phase separator but their efficiency is low. Converging T-junction with two distinct diameters (primary and secondary) in branch arm is used to improve the phase separation efficiency. The motivation is to combine specific feature of regular and reduced T-junction to increase separation efficiency of existing T-junction without involving too much operational workover. The purpose of this paper is to numerically evaluate the separation efficiency of a converging T-junction design. The present model and its methodology was validated with in-house experimental data for 3 inches diameter flow loop.

The slug flow regime was simulated using incompressible Eulerian mixture model coupled with volume of fluid method to capture the dynamic gas-liquid interface.

The analyses concluded that T-junction with primary-secondary branch arm diameters combination of 1.0-0.5 and 0.67-0.40 managed to achieve 95 per cent separation efficiency. The research also confirmed that over reduction of T-junction secondary diameter ratio below 0.2 will lead to decrease in separation efficiency.

The present research is limit to air/water two-phase flow but the general results should be applicable for wider application.

The proposed design limited excessive workover and installation for current and existing T-junction. Hence, cutting down installation cost while improving the separation efficiency.

The present research resulted in higher separation efficiency, cutting down production down time and lead to operational cost saving.

The present research proposes an original and new T-junction design that can increase phase separation efficiency to over 90 per cent. The finding also confirmed that there is a limitation whereby smaller diameter ratio T-junction does not always resulted in better separation.

The purpose of this paper is to assess the waste characteristics and separation efficiency of source separation of household waste in low- and middle-income communities in Kumasi Metropolis, Ghana.

A sample of 60 households participated in the household survey, education on source separation and pilot source separation exercise. The solid waste was sorted into six fractions and three recycling categories (biodegradable; paper and plastic; residue).

The mean generation rate of solid waste was 0.52±0.26 kg/per capita/day for the low-income community and 0.65±0.27 kg/per capita/day for the middle-income community. The waste fractions in the communities (low, middle income) were biodegradable organics (59.15, 65.68 per cent), plastics (11.01, 10.68 per cent), papers (3.15, 4.51 per cent), glass (0.89, 2.57 per cent), metals (0.96, 4.63 per cent) and miscellaneous (24.84, 11.93 per cent), respectively. The separation efficiency for organic category was 70 per cent, inorganic and residue was over 69 per cent and the paper and plastics was over 60 per cent.

The study suggests that the success of source separation programme hinges on education and economic incentives. It was noted that the sample size could be increased to enhance the accuracy of the data for prediction purpose.

The findings showed there is potential for recycling through source separation programme in low-and middle-income communities. Public education and economic incentives are necessary for successful source separation programme.

The paper provides insight into source separation to contribute to better understanding of how city authorities in developing countries could take advantage of economic incentives to scale-up recycling.

Dynamic separator is an equipment having a rotor and static vanes and is used to separate solids from gas-solids flow based on size. Particle separation in a dynamic separator happens due to complex interchanges between multiple forces exerted in the separation zone. Currently, there is only limited knowledge concerning the working principles of separation. This paper aims to systematically study a dynamic separator using numerical models to get insights into particle separation.

The Lagrangian–Eulerian formulation is used to simulate gas-solid flow. Multiple frames of reference using stage interpolation are used to account for rotation. Periodic symmetry in the equipment is exploited to create a simplified numerical model. The predictions from the numerical model are compared against available experimental data.

The numerical results indicate that only when particle collision is included, the separation efficiency trend from the experiment is matched by numerical predictions. Further, it is shown that at the same range of rotor speeds where numerical results predict increased separation efficiency, the solid pressure due to particle collision also reaches its maximum value. The gas flow and particle behavior in the separator are explained in detail.

The importance of particle collision in separation is interesting because traditionally, particle separation is assumed to be influenced by three forces, namely, centrifugal force, drag force and gravity. The numerical results, however, point to the contribution by particle collision, in addition to the above three forces.

In view of the current difficulty of separation of troxerutin, the purpose of the paper is to separate and purify semi-synthetic flavonoid compound troxerutin by macroporous adsorption resin (SZ-3).

Comparing the adsorption performance and resolution of three different polar resins and choosing a resin to optimize the process parameters such as sample volume, eluent concentration and elution temperature to obtain high-purity troxerutin. After separating and enriching by resin column chromatography, detected the sample by LC-MS analysis.

This research found that the optimal conditions of the adsorption and desorption were sample volume S = 90 mg/g resin, methanol concentration C = 25%, T = 20 °C. the content of troxerutin increased significantly from 88% to more than 96%. Then confirmed the sample was troxerutin by LC-MS. In addition, the resin could be used for at least 10 cycles in the separation and purification experiments of troxerutin.

Purification of troxerutin with new SZ-3 resin for the first time. Under the optimal conditions, the purity and recovery of troxerutin was 96.4% and 39%. In this study, the authors established a purification process of troxerutin successfully that was simple, economical, environment friendly, with high purity and high recovery rate to provide a reference program for changing the status of troxerutin separation difficulties.

The purpose of this study is to focus on simulation of wire mesh demisters in multistage flash desalination (MSF) plants. The simulation is made by the use of computational fluid dynamics (CFD) software.

A steady state and two-dimensional (2D) model was developed to simulate the demister. The model employs an Eulerian-Eulerian approach to simulate the flow of water vapor and brine droplets in the demister. The computational domain included three zones, which are the vapor space above and below the demister and the demister. The demister zone was modeled as a tube bank arrange or as a porous media.

Sensitivity analysis of the model showed the main parameters that affect demister performance are the vapor velocity and the demister permeability. On the other hand, the analysis showed that the vapor temperature has no effect on the pressure drop across the demister.

The developed model was validated against previous literature data as well as real plant data. The analysis shows good agreement between model prediction and data.

This work is the first in the literature to simulate the MSF demister using CFD modeling. This work is part of a group effort to develop a comprehensive CFD simulation for the entire flashing stage of the MSF process, which would provide an extremely efficient and inexpensive design and simulation tool to the desalination community.

Higher order statistics (HOS)-based blind source separation (BSS) technique has been applied to separate data to obtain a better performance than second order statistics-based method. The cost function constructed from the HOS-based separation criterion is a complicated nonlinear function that is difficult to optimize. The purpose of this paper is to effectively solve this nonlinear optimization problem to obtain an estimation of the source signals with a higher accuracy than classic BSS methods.

In this paper, a new technique based on HOS in kernel space is proposed. The proposed approach first maps the mixture data into a high-dimensional kernel space through a nonlinear mapping and then constructs a cost function based on a higher order separation criterion in the kernel space. The cost function is constructed by using the kernel function which is defined as inner products between the images of all pairs of data in the kernel space. The estimations of the source signals is obtained through the minimizing the cost function.

The results of a number of experiments on generic synthetic and real data show that HOS separation criterion in kernel space exhibits good performance for different kinds of distributions. The proposed method provided higher signal-to-interference ratio and less sensitive to the source distribution compared to FastICA and JADE algorithms.

The proposed method combines the advantage of kernel method and the HOS properties to achieve a better performance than using a single one. It does not require to compute the coordinates of the data in the kernel space explicitly, but computes the kernel function which is simple to optimize. The use of nonlinear function space allows the algorithm more accurate and more robust to different kinds of distributions.

New legislation to encourage the recycling of end of life electronics and moves to implement sustainable development in electronics manufacturing have focussed attention on the large quantity of printed circuit boards (PCBs) being consigned to landfill. Also, in a recent investigation conducted on behalf of the UK's Department of Trade and Industry, the need for new methodologies for dealing with end of life circuit boards was identified as a priority issue. Within the UK it is estimated that ∼50,000 tonnes per annum of PCB scrap is currently generated and investigations indicate that only ∼15 per cent is subjected to any form of recycling, with the remainder consigned to landfill. This paper reports the results of a scoping study carried out to identify the technologies and processes that can be used to recycle materials from end of life PCBs.

Vinyl acetate was polymerised at −24°C, under an atmosphere of nitrogen and using an Hanovia 100‐W mercury arc lamp, by Atkinson et al. (2) who then subjected the product to preparative GPC using a Waters Associates AnaPrep chromatography unit fitted with columns (1.2m × 2.5cm dia. or 1.2m × 6.25cm dia.) that were packed with Styragel chosen to suit the MSD of the samples as previously determined in a separate analytical GPC run. Fractions from several runs, that were obtained by elution with toluene at a flow rate of 15mL min−1, were combined together prior to recovery of the polymer samples by freeze drying the solutions now in benzene. The Mn of each fraction so obtained was determined in toluene at 40°C using a Hewlett‐Packard model 502 osmometer fitted with Arro 450 special membranes.

This paper aims to study the effect of chloride ions concentration on the corrosion behavior of carbon steel in methyldiethanolamine (MDEA) aqueous solution in the sight of different process parameters of purification plant.

Due to the decrease of filtration efficiency and separation efficiency, the chloride ion in the desulfurization solution is enriched. The corrosion behavior of carbon steel under chloride ion enrichment environment was studied by weight-loss method, electrochemical impedance spectroscopy, cyclic polarization curve, X-ray photoelectron spectroscopy and scanning electron microscopy.

The results show that temperature and hydrogen sulfide loads are the main factors of corrosion in CO2-MDEA-H2O-H2S environment. The enrichment of chloride ions reduces the corrosion rate at low temperature but promotes the corrosion rate at high temperature. The chloride concentration should be controlled below 3000 mg/L, and no pitting corrosion was found under the experimental conditions.

The effect of chloride ion enrichment on MDEA solution corrosion shows that at low temperature, the increase of chloride ion will reduce the acid gas load and increase the density of corrosion products, so as to reduce the corrosion; on the contrary, at high temperature, the density of corrosion products will decrease and the corrosion will be intensified as well. It is believed that the chloride ion should be controlled below 3000 mg/L according to the results of the tests.

This study aims to review the current one-step electrodeposition of superhydrophobic coatings on metal surfaces.

One-step electrodeposition is a versatile and simple technology to prepare superhydrophobic coatings on metal surfaces.

Preparing superhydrophobic coatings by one-step electrodeposition is an efficient method to protect metal surfaces.

Even though there are several technologies, one-step electrodeposition still plays a significant role in producing superhydrophobic coatings.