incorrect utilization of cement Kiln returned dust not only can produce variations in Kiln operation conditions, resulting in the corresponding undesirable consequences such as decrease in clinker quality, but also may lead to the enhancement of volatiles circulation and the subsequent repeated Kiln stoppages due to the phenomenon of cyclone jamming. The importance of regulating the amount of returned dust content of Kiln feed should be considered since higher contents of volatile constituents in Kiln returned dust along with their considerably higher volatilities compared to the corresponding fresh Kiln feed are liable factors for the enhancement of volatiles circulation.

In this study, the efficiency of radiofrequency/vacuum (RF/V) technology for drying of pine wood (Pinus sylvestris) was investigated compared to the hot air convective method. For this purpose, flat-sawn boards with dimensions of 4. 8 × 21 × 120 cm, heartwood percentage of 72. 9% and average green moisture content of 60% were cut. The boards were dried using three methods: (1) an industrial conventional Kiln at low temperature (maximum temperature of 50 °C) and (2) normal temperature (maximum temperature of 71. 3 °C) according to a 20 step-modified drying schedule and (3) RF/V Kiln. RF/V drying was performed in an industrial Kiln with a power of 100 kW and a frequency of 50 MHz according to a 6 step-drying schedule with a maximum temperature of 65 °C. Then, final moisture content, moisture gradient, discoloration, wood drying defects and stresses were measured. The results showed that in addition to a significant reduction in the drying time of the boards in the RF/V Kiln, the intensity of surface and end-checks in RF/V drying was significantly lower than that in conventional drying. All dried boards were free from internal checks. The maximum twist and cup were 4. 8 and 5. 4 mm, respectively, and no difference was observed in the efficiency of the three wood drying methods. Unlike conventional dried boards, the boards dried in RF/V Kiln showed no casehardening. Moisture gradient in all dried boards was negligible (less than 2%). The discoloration of the boards dried by RF/V was lower compared to other dried boards.

Rotary cement Kiln as heart of a cement production plant plays an important role in overall energy consumption and product yield. Therefore, the process behavior and physical parameters affecting the final production need to be investigated. Modeling and simulation of the rotary cement Kiln have been done by several researchers considering dynamic and steady state behavior of the process. In this research, different models presented by other researchers were evaluated and their advantages and disadvantages were studied. Next, a general and comprehensive model was developed with the aim of optimization of the process. Due to the complexity of the Differential and Algebraic Equations (DAEs) constructing the model, a powerful method should be employed in order to solve the complex system. Simulation results were compared to the result from a case study presented in the literature. Moreover, Genetic Algorithms (GA) was used as a strong tool to find optimum parameters and operating conditions for production of different cement types. Having maximum production as objective function, different values for the parameters and conditions were resulted from the numerical optimization of the process. It was found that for some fixed plant geometries, different optimum values exist for production of a specified cement type.

The archaeological site of Moshkouyeh that nowadays called Moshkin tape is located in northern part of the Iranian plateau, between the two historical cities of Rey in the north and Saveh in the south. The two terms can be considered for the word of the Moshkouye: A) Moshkouye was a region where the hunting of gazelle and extraction of musk was carried out there. B) Moshkooy can be considered a kings palace or harem. By Searching in historical resources, it became clear that nowadays Moshkin Tape is the same as historical Moshkouye that was settlement in Khurasan Road. After reading the historical texts, the systematic survey of the site showed that pottery shards and pottery equipment could be the remains of an industrial city from the Seljuq Era. Archaeological excavation in 2008 indicated this small city has produced the pottery required by inhabitants of Rey and many villages in the political and cultural region of Rey during the 5th and 6th centuries after Hijrat. This paper analyzes the structure, function and chronology of excavated Kilns. This aim has been achieved through the analyses and interpretation of ceramic along with ethnographic studies, historical resources and especially archaeological data which has been yielded from Moshkin tape survey and excavation.

The cement industry is one of the major industries in every country. This industry is the driving force behind the development of a nation. The heart of this industry is the rotary Kiln. One of the significant concerns about a rotary Kiln is forming a cover of molten materials on the Kiln's inner wall called coating. The low thickness of this coating cause burns to the wall refractory bricks and heavy damage to the Kiln, while its high thickness reduces the production volume and quality of products. Currently, the Kilns are checked by experienced technicians for empirical coating estimation. This paper aims to identify the thickness of the coating for the automatic control purpose of the Kiln. The identification problem of coating thickness is based on thermal resistances in different layers of the Kiln and heat transfer equations between these layers. For this purpose, linear and nonlinear identification methods such as Ordinary Least Squares (OLS), Recursive Least Squares (RLS), global search methods, and genetic algorithms are used. The coating can be identified in the proposed identification approach by having the Kiln's ambient and internal solid temperature profiles. The raw data for the identification process has been extracted by Finite Element Analysis (FEA) for a given solid temperature profile along with the Kiln and different Kiln coating thicknesses. The modeling and simulations carried out in this paper show that the identification methods were able to determine the amount of coating with acceptable errors depending on the method.

Dynamic simulation of rotary cement Kiln is a useful tool to study its behavior in different operating conditions. In this work a generalized cement Kiln model, which is a highly non-linear distributed parameter system, was developed. Partial Differential Equations (PDE's) were discretized in spatial direction, applying Orthogonal Collocation (OC) technique. The model comprises differential equations as well as non-linear algebraic constraints. The NIMBUS dynamic simulation package (Newell and Cameron 1991) [1] was used to solve the resulting differential and algebraic equations (DAB's). The DAB's were solved simultaneously via sparse and dense numerical methods. Dynamic responses of the model to step changes in some manipulated variables were studied to predict open loop behavior of the system. The step changes include increase or decrease in gas and solid temperatures as well as solid and gas velocities. Sensitivity study indicated that the model successfully predicted qualitative behavior of an actual cement Kiln.

Cordierite-Mullite based Kiln furnitures are widely used in fast-firing of ceramic products because of their low thermal expansion which confer them a very good ability to thermal shock resistance. Difference in CTE of constituent phase can develop damage during thermal cycling due to internal stresses. Increase in industrial competitiveness leads to the development of new means for extending refractory life and increasing reliability of industrial tools so investigations regarding the structural\mechanical behaviour of refractory systems are becoming essential. In this paper, Thermo-mechanical design of commercial Cordierite-Mullite based Kiln furniture was investigated by using finite element method (FEM) and possible solutions for improvement of working life have been considered. The results indicated that the change of the Kiln furniture geometry can decrease the maximum thermo-mechanical stress in study conditions which can prolong the refractory service life. Obtained results indicate the existence of an optimal thickness for the section under maximum thermo-mechanical stress. Increasing filet radius of ring region from 3 to 9 mm decreases thermo-mechanical stress value from 113 to 93 MPa.

The bed depth or the amount of charge material is an important parameter that can affect the heating, sintering, coating and moving of material along the Kiln and the control process in a rotary Kiln. An inverse geometry heat conduction problem is solved to detect the unknown location of the surface of the charge material or unknown bed depth in the rotary Kiln. The finite volume method is employed to discretize the governing equation of the direct problem domain and the inverse model is constructed to identify the unknown boundary location. A sequence direct problem is solved in an effort to update the boundary geometry by minimizing an objective function. The objective function is constructed by summation of the squared differences between the actual and computed temperatures at the sensor locations. This function (objective function) is minimized, based on the two optimization algorithms, (L-MM) and (CGM) methods. Since, for each optimization step, a new grid is generated in the computational domain, this producer may be defined as one kind of an inverse geometry problem. In another way, by estimating the unknown location of the bed surface (bed depth) for each cross section of the Kiln, the amount of charge material at this slice can be obtained.

A huge part of the thermal energy consumed in energy industries is lost after exiting the process. Some of this waste heat can be recovered by various methods such as generating electrical energy, generating hot air for the production process or providing hot water. In Iran, the cement industry has always been far from the optimal use of resources, including energy, due to the existence of energy subsidies. In this research, the heat loss from the baking system of Nireez white cement plant as a model industry of the country to evaluate the simultaneous production of heat and electricity by using the organic Rankine cycle that generates electric power has been investigated in Span Plus V12 software. This evaluation is done to calculate the heat loss, including the mass and energy balance on the cooking system, as well as the energy balance on the pre-cooking system. The heat energy obtained enters the Rankine cycle and is converted into energy by the turbine. The results show that 635 kilowatts of electrical energy was produced from energy recycling, which leads to the elimination of 317.5 kg/hour of greenhouse gas.

In this research, beech (fagus orientalis Lipsky) lumbers at 5 cm thickness were ran domically selected and commercially cut down from sari region (Neka choob company), with three schedule namely T5-C3, T5-C4, T6-C4 were adapted for drying the lumbers down to the final moisture content of 8% to evaluation the effect of Kiln schedule on warp and surface checking. primary dry bulb temperature each three schedules was adjusted at 49 °C and the final dry bulb temperatures was adjusted at 71, 71 and 82°C respectively. Basic Specific gravity and dry specific gravity were measured 0.52 and 0.61 respectively. Longitudinal, radial, tangential and volumetric shrinkage were measured 0.46 %, 5.8%, 10.2%, 16.46% respectively.Quantity of defect s including crook, bow, twist and three longest surface checks of the lumber were measured before and after the drying process in each stage. In order to analysis the lumber defects for estimating the best schedule, quality control graph were used. In the end, results of investigation indicated that drying of beech lumber by using of the three schedules was desired.However the third schedule (T6-C4) had better drying characteristics than the other schedules.