Determining pressing rates for refractory semidry bodies

Conclusions An inverse relationship was established for the permitted pressing rate and the ratio between the volume of the products and its double perimeter in plan. With an increase in the dimensions of the article it is necessary to reduce the pressing rate to exclude the formation of pressing cracks.Empirical equations are proposed which as a first approximation can be used for calculating the average rates and durations of pressing, and also for accumulating data connected with the question under discussion.Translated from Ogneupory, No. 5, pp. 17–21, May, 1971.     

Improvement of chemical monitoring of water-chemistry conditions at thermal power stations based on electric conductivity and pH measurements

The increased requirements to the quality of the water heat conductor for working superhigh (SHP) and supercritical (SCP) pressure power plants and promising units, including combined-cycle gas turbine (CCGT) units and power plants with ultrasupercritical parameters (USCPs), can largely be satisfied through specific electric conductivity and pH measurements for cooled heat conductor samples combined with calculations of ionic equilibria and indirect measurements of several specified and diagnostic parameters. The possibility of calculating the ammonia and chloride concentrations and the total concentration of hardness and sodium cations in the feed water of drum-type boilers and the phosphate and salt contents in boiler water was demonstrated. An equation for evaluating the content of potentially acid substances in the feed water of monotube boilers was suggested. The potential of the developed procedure for evaluating the state of waterchemistry conditions (WCCs) in power plants with CCGT units was shown.     

Temperature dependences of methane elution on a Cu<Subscript>3</Subscript>(BTC)<Subscript>2</Subscript> metal-organic framework

Methane elution from a helium flow was studied on a metal-organic framework Cu₃(BTC)₂ with gas chromatography under temperatures from 20 to 60°C. Specific retention volumes were calculated, and heat of adsorption was determined. The obtained values are characteristic for the microporous adsorbents having relatively large micropores and a low total volume of the micropores. The calculated efficiencies of an adsorbent layer alter slightly and their absolute values are significantly smaller than those of the activated carbons. Efficient kinetic constant has a parabolic dependence on temperature with a minimum at 40°C. Correctness of the developed algorithms to calculate elution constants on adsorbent layers of small length has been confirmed.     

A calculation method for determining the concentration of potentially acid substances in feedwater of once-through boilers

The problem of chemically monitoring the products resulted from destruction of organic substances in the steam-water path of a supercritical-pressure power unit is considered. The level at which the concentrations of acetic and formic acids have to be measured is determined, and the results from measurements of electric conductivity and pH in feedwater and steam are given. A procedure that allows the conditional concentration of acetic acid in steam to be calculated from measured electric conductivity in feedwater and steam is presented.     

Use of refractory SHS mortar GAMMA-3KhP in rotary furnaces and stationary heating units of nonferrous and ferrous metallurgy

The objective difficulties of the present time have led to substantial changes in the operation of many heating units in nonferrous and ferrous metallurgy, in enterprises producing building materials, in the chemical industry, etc     

On calculation of the effectiveness of a low-length adsorbent layer

The exact solution of elution linear dynamics of adsorption (chromatography) representing the ratio of the subintegral function of gamma function to the actual Euler gamma function is analyzed. A new equation for calculation of performance of a low-length column is substantiated when an addend in the form of an additional constant is introduced into the known expression determining the number of plates. Additional constants are calculated for three levels of the peak height that little differ from each other and are ～1.1. The obtained results are compared to the experimental elution curve of trifluorochrloromethane on a low-length active carbon layer and good agreement is found between the theory and experiment.     

Impurity localization in aluminum oxide compounds

Heat-treatment products of commercial γ-Al(OH)₃ (gibbsite) were characterized by X-ray diffraction, scanning electron microscopy, and energy dispersive X-ray fluorescence spectrometry with the aim of localizing impurities in the parent material. The results suggest that at least a fraction (about half) of typical impurities in the form of readily soluble aluminates is localized in the surface layer of gibbsite particles.     

Water chemistry of a combined-cycle power plant’s auxiliary equipment cooling system

Results from an analysis of methods aimed at reducing the corrosion rate of structural metal used in heat-transfer systems with water coolant are presented. Data from examination of the closed-circuit system for cooling the auxiliary mechanisms of a combined-cycle plant-based power unit and the results from adjustment of its water chemistry are given. A conclusion is drawn about the possibility of using a reagent prepared on the basis of sodium sulfite for reducing the corrosion rate when the loss of coolant is replenished with nondeaerated water.     

A study and selection of conditions for coagulating water at OAO Severstal’s cogeneration station

Laboratory studies on determining the efficiency of purifying low-mineralized water with an increased content of organic substances by means of different coagulants and flocculants are carried out. The best results are obtained for aluminum hydroxychloride and aluminum sulfate with adding small quantities of type 2520TR flocculant produced by Ashland and AN-910 PWG flocculant produced by SNF. Results obtained from industrial tests carried out in a horizontal plate-type clarifier are presented.