Steps of membrane blocking in flux decline during protein microfiltration

Electrical field: A historical review of its application and contributions in wastewater sludge dewatering

The group contribution method Modified UNIFAC (Dortmund) is a well-known model for the reliable prediction of phase equilibria (VLE, LLE, SLE of eutectic systems, azeotropic data and γ∞) and excess...

A Modified UNIFAC (Dortmund) Model. 3. Revision and Extension

The availability of drinking water is reducing day by day; where as the requirement of drinking water is increasing rapidly. To overcome this problem there is a need for some sustainable source for the water distillation (purification). Solar still is a useful device that can be used for the distilling of brackish water for the drinking purposes. In this article a review has been done on different types of solar still.

Solar stills: A review

The fresh water requirement is tremendously increasing in the present society with all kinds of industrial and factory growth leading to more and more pollution of natural resources. On the other hand, there are many arid and desert regions in the world where there are less frequent rainfalls and ground water shortage. Most of the water bodies like rivers, lakes and so forth throughout the world are saline and brackish which are not suitable for domestic, irrigation and especially for drinking purposes. Solar desalination is proven to be eco-friendly and economical way of producing the fresh water to cater to the needs of rural population. Much research has already been done in the field of single effect passive and active solar stills which produces low quantity of fresh water. In recent years, attention has been focused on developing multi-effect solar stills coupling with flat plate and concentrating collectors in order to overcome the drawback of single effect stills. In the present study, a detailed review of all the solar stills both single and multi-effect type with passive and active configuration is presented. The present study aims at describing the design specifications and highlighting the merits and demerits of various solar stills upon which research has been done till recent past. Also a discussion on future scope is given with some recommendations in the field of solar stills improvement to economically produce sustainable potable water.

Solar stills system design: A review

The definition of filtration resistance is modified by considering relative solid-liquid velocity.

The internal flow mechanism in a filter cake is reexamined in view of the movement of solids during compression. Under conditions of short filtrations involving highly concentrated slurries, the velocity of solids is shown to be comparable to the velocity of the liquid. A differential equation is proposed for the flow through compressible cakes in which the pressure gradient is assumed proportional to the difference in average velocities of the liquid and solid rather than to the average velocity of the liquid alone.

An improved definition of the average filtration resistance is developed on the basis of the new flow equation.

Internal flow mechanism in filter cakes

= coefficient in Eq.(ll) = coefficients in Eq. (12) = coefficients in Eq.(l3) = feed concentration of solid = diameter = collection efficiency of cyclone = feed rate of particles = particle hold-up Ki, K2 = coefficients in Eq.(8d) kpe -coefficient in Eq.(3) [-] [-] [-] [kg-solid/kg-air] [m] [kg/kg] tkg/s] [kg] r I = length of duct = penetration of particles through cyclone = radius of curvature of curved duct = dimensionless group denned by Eq.(8d) or Eq. (8c)

Predictions of constant pressure and constant rate f1ltrations based upon an approximate correction for side wall friction in compression permeability cell data

To examine the propriety of the so-called "modern filtration theory", porosity variations in constant-pressure filtration cakes are measured electrically by means of filter equipment having six pairs of disk-type electrodes. Experimental results show good agreement with the theoretical values predicted by filtration theory on the basis of compression-permeability data. The so-called "retarded packing compressibility" phenomena previously presented by Rietema et al. are not recognized through all runs attempted in this study.

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Tsutomu Aragaki

Papers

Internal flow mechanism in filter cakes

Predictions of constant pressure and constant rate f1ltrations based upon an approximate correction for side wall friction in compression permeability cell data

Porosity variation in filter cake under constant-pressure filtration

Dynamic characteristics of a multistage thermal diffusion type solar distillator

Simulation of a multieffect solar distillator