Solutions using the Recursive Operator Method for the Dynamic Equations of Heat and Mass Transfer in Hardening Concrete under Heat Treatment in a Heating Chamber

In the work, the authors investigated the possibility of using the results of analytical solutions of the linear differential equations of unsteady heat conduction with constant heat transfer coefficients to calculate the temperature of the material during heat treatment of leathers. Heat treatment of natural leathers as heat-sensitive materials is carried out under mild temperature conditions and high air moisture contents, the temperature does not undergo significant changes, and the heat transfer coefficients change almost linearly. When using analytical solutions, the authors made the assumptions that for small temperature gradients over the cross section of a thin body, the thermal transfer of matter can be neglected and for values of the heat and mass transfer Biot criteria less than unity, the main factor, limiting heat and mass transfer, is the interaction of the evaporation surface of the body with the environment; so, in solving the differential heat equation we can restrict ourselves to one first member of an infinite series. In this case, a piecewise stepwise approximation of all thermophysical characteristics with constant values of these coefficients at the calculated time intervals was applied, which made it possible to take into account the change in the transfer coefficients throughout the entire heat treatment process. Processing of experimental data showed that in low-intensity processes with reliable values of the transfer coefficients, it is possible to use the results of solutions of differential equations of unsteady heat conduction in heat transfer calculations. The results of the study of heat transfer during drying of leather confirm the laws of temperature change established experimentally. Together with experimental studies of drying processes, analytical studies are of great practical importance in the development of new methods for calculating heat and mass transfer in wet bodies.

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Recursive-operator method in vibration problems for rod systems

Mechanics of Solids ◽

10.3103/s0025654409060090 ◽

2009 ◽

Vol 44 (6) ◽

pp. 915-926 ◽

Cited By ~ 1

Author(s):

E. V. Rozhkova

Keyword(s):

Operator Method ◽

Recursive Operator ◽

Vibration Problems ◽

Recursive Operator Method

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Optimization Of Heat And Mass Exchange Processes In Processing A Cell Of Oil Crops

The American Journal of Applied Sciences ◽

10.37547/tajas/volume02issue10-18 ◽

2020 ◽

Vol 02 (10) ◽

pp. 122-132

Author(s):

U.A. Saidmuratov ◽

Keyword(s):

Heat Treatment ◽

Mass Transfer ◽

Heat And Mass Transfer ◽

Cotton Seed ◽

Optimization Problems ◽

Two Phase ◽

Heat And Mass Exchange ◽

Processing Methods ◽

The Hierarchical Structure ◽

Physical Processing

One of the promising areas in the technology of oilseed processing is electro physical processing methods. The use of electrophysical processing methods dramatically accelerates the flow of processes, increases labor productivity, reduces the need for production facilities, and in some cases reduces energy consumption. Based on the foregoing, it is possible to formulate the main goal of studying the process of heat treatment of cotton seed mint in a two-phase flow: to identify rational conditions for the process, to outline rational ways for effective structural design of the apparatus for heat treatment of cotton seed mint. Achieving this goal should ensure a reduction in the energy and material consumption of the process, an increase in the yield of black oil, an improvement in the quality indicators of the final products and working conditions of the staff. The analysis of technological processes occurring in a single biological cell of peppermint of cotton seeds is important, among other things, because it allows us to outline ways of choosing and synthesizing optimal process parameters, and to develop highly efficient plants. However, the solution to the problems of optimization of continuous heat and mass transfer (HMT) processes occurring in apparatuses or installations as a whole as L-optimization is labor intensive, since when considering complex HMT systems, the number of optimizing factors increases. In the systems under consideration, the number of main factors exceeds 20, even if they vary at two levels, more alternative options are required for optimization. The functional decomposition of optimization problems was carried out based on the hierarchical structure of the HMT systems, in which the hydrodynamic structure of the interacting flows is considered as the main central subsystem-processes, which are subsequently divided into more than elementary heat and mass transfer (HMT) processes. Optimization of the lower levels of technological plants for the implementation of solid-state processes is considered for IR - roasting in a solvent medium (IR-LCMSR).

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