Use Of Surface-active Substances Research Articles

SYSTEM ANALYSIS OF THE SULFATION PROCESS IN THE PRODUCTION OF SURFACTANT SUBSTANCES

Data on the use of surface-active substances in various areas of Ukrainian industry are given. The rapid development of the production of surface-active substances is shown. The main stages of the production of surface-active substances are given. It is shown that the sulfation stage is the main one, at which high quality indicators of the obtained products are achieved.
 The main disadvantages and advantages of sulfating agents in the technology of surface-active substances (surfactants) are given. The characteristics of the equipment and technological schemes of the sulfation process of organic substances are given.
 It is claimed that the use of tubular film absorbers with a downward flow of phases is currently the most promising for use in industrial conditions.
 Convective diffusion equations for the simplified models of Lewis – Whitman, Levich, Higby, Dankverts are given.
 It is proposed to present the process of sulfation in a tubular film absorber with the following stages: the process of mass transfer of gaseous sulfur trioxide to the surface of the interface, the process of absorption of sulfur trioxide by an organic substance with the passage of an exothermic chemical reaction, the process of heat exchange between the liquid phase and the gaseous air flow, the process of heat exchange between the liquid phase and the flow of cooling water. The equation for calculating the mass transfer coefficient is given, which allows obtaining data close to Gutierrez's experimental data. The passage of successive chemical reactions during the absorption of sulfur trioxide by organic raw materials is shown. Kinetic equations and methods of calculating the degree of sulfation and color of the obtained products are given. Basic equations for calculating heat transfer coefficients and heat transfer coefficients are given.
 The results of mathematical modeling of the sulfation process in a tubular film absorber are given.
 The possibility of achieving high quality indicators of the obtained product is shown: the degree of sulfation is 97,9 %, the color is 1 unit on the iodine scale.

Heat transfer enhancement in steam-turbine condensers with the use of surface-active substances

A technology of the enhancement of the power efficiency of steam-turbine plants (STPs) is proposed by the treatment of surfaces of a piped condenser system over the steam and water sides with the use of surface-active substances (SAS). The transition of filmwise condensation into dropwise makes it possible to increase the heat-transfer coefficient by 50–70% because of hydrophobization of outside surfaces of the steam side that results in vacuum extension at minimum operating costs. The resulting data are verified by laboratory investigations and full-scale tests. The accumulation rate of thermobarrier deposits over the water side decreases by a factor of 6–8, and, correspondingly, the overhaul life connected with the refinement of condenser pipes increases. The maintenance of the hydrophobic film of SAS at the outside surface of condenser pipes can be provided by the periodic injection of SAS on the inlet of a low-pressure cylinder (CLP) of the turbine both in the period of short-time stops and during the operation of STPs. At the same time, because of the additional dispersion of the liquid phase, the rate of drop-impact erosion of the blade row decreases by 30%.

Development of innovative resource-saving technologies of utilization of the oil containing wastes

Formation of wastes is a considerable problem for enterprises and structural subdivisions of railways. Technological heavy mineral oils and oils apply to such wastes annually accumulating in great amounts. The method of utilization depends on composition of waste, his properties and amount. In article traditional methods of utilization and renewal of the fulfilled lubricant cooling fluids, petropolluted soil, used motor oils of separate brands are considered. The analysis of current technologies and schemes of regeneration and utilization of the oil containing wastes led to drawing the conclusion that the physical-and-chemical methods are the most promising, in particular the use of different types of advanced surface-active substances (surfactants). We conducted the laboratory studies to recover the properties of the oil containing wastes with a wide range of surface-active substances (surfactants). Specifically, some quantity of surfactants tested, among which oxyethylated monoalkylphenylic acid (neonol AF 9-12) for lubricant cooling fluids, Syntanol ALM-10 for petropolluted soil, neonol AF 9-12 for motor oil gave the best results. In developing the scheme of recovery of operating quality of the oil containing wastes for the purpose of forming and calculating the process flow diagram suggested, the process optimization, namely temperature, reagent amount, and time of its contact with oil was conducted. The new technologies with use of surface-active substances are offered.

Use of surface-active substances for reducing hydrocarbon liquids volatility with their long-term storage

The problem of hydrocarbon liguids vaporability suppression . Existing pysico-chemical metods are unalysed, neccisity and a new compositions for hydrocarbon liguids vaporability suppression are based.

Cold isostatic pressing as a method for fabricating ceramic products with high physicomechanical properties

The experimental results published by the author and his co-workers in 24 earlier works and novel original data are analyzed. It is shown that the process of cold isostatic pressing (CIP) occurs with mechanical activation of the powder particles due to their self-deformation with a simultaneous self-compaction of the semiproduct. The CIP process of powders or traditionally shaped preforms is shown to elevate their density and activate the sintering processes but diminish their sintering temperature and increase the density, strength and crack resistance of the ceramics. The use of surface-active substances (SAS) in CIP is shown to elevate the level of the physicomechanical properties of the ceramics. The basic concepts of controlling the properties of ceramics by choosing the appropriate dispersity of the powder, the CIP pressure, the SAS, and the sintering regime are presented.

Preparation of manganese dioxide dispersions in dimethylformamide and their use for spinning filled fluoroplastic fibres

The properties of manganese dioxide dispersions in dimethylformamide in the presence of various surface-active substances (SAS) have been investigated. It has been found that the use of SAS aids in loosening the structure of the fluoro-resin fibre spun with no filler, nitrogen-containing SAS exerting a more significant effect on the sorptive properties of the Ftorlon fibre. The use of SAS not only facilitates dispersion of the filler, but also exerts a significant effect on the porosity of the filler fluoro-resin fibre.

Theory and practice of the use of surface-active substances in the manufacture of viscose fibres

The manufac tu re of v i s c o s e f i b r e s i s c h a r a c t e r i z e d by a l a r g e v a r i e t y o f d i s p e r s e sys tems, and chemical and physicochemical processes. This brings about a high effectiveness of using surface-active agents (SAA). At present they are widely used in practically all stages of the technological process in preparing the viscose and getting it ready, in spinning the fibre, finishing it, and in textile operations.

Use of surface-active substances in microbiological transformations of steroids

Use of surface-active substances in microbiological transformations of steroids

Conference on the use of surface-active substances

Conference on the use of surface-active substances

Use of surface-active substances in the extrusion of hard alloys

1. A study was made of the possibility of adding surface-active substances to a plasticizer (paraffin wax) and their effects on the extrusion characteristics of hard-alloy mixtures and quality of finished parts. It was established that the addition of 1% of a SAS to 5% of paraffin wax facilitates deformation through an adsorption effect, the extrusion pressure thus being lowered by 100 kg/cm2. 2. Surface-active substances considerably simplify the preparation of a mixture for extrusion by eliminating the process of repeated mixing through a multiple-channel die.

Use of surface active substances in the production of earthenware wall tiles

Use of surface active substances in the production of earthenware wall tiles