Modelling and design of conveyor belt dryers (original) (raw)

Design and operational performance of conveyor-belt drying structures

The design and operational characteristics of conveyor-belt dryers constitute an important field of chemical engineering, which is still governed by empiricism. In this work, both aspects were studied in a straightforward way based on mathematical reasoning. A mathematical model describing the convective drying process was developed. Design procedures aimed at the determination of optimum equipment arrangement, size and operational characteristics for conveyor-belt dryers were carried out by optimizing the total annual cost of each equipment arrangement for a given production capacity. All dryer arrangements were compared by evaluating optimum configurations for a wide range of production capacity values. Once the dryer configuration was specified, its operational performance was evaluated by comparing the optimum operational cost versus production capacity for a specific optimum designed structure. An example covering the drying of sliced potato is included to demonstrate the performance of each design case, as well as the effectiveness of the proposed approach. 0 1998 Elsevier Science S.A.

Simulation of continuous flowgrain dryers

2013

Mathematical model and a computer program were developed to simulate the performance of continuous flow grain dryers. The mass and heat transfer processes were described by a system of four non-linear partial differential equations. This system was solved by the MacCormack method. Methods of Neumann and Matrix (considering the border conditions) were used for analysis of the convergence. The source-terms in these equations were defined by auxiliary semi-empirical equations, which were obtained by experimental data in the thin layer. In order to validate the model, the experiments were conducted in fixed bed. Simulations were made for various schemes of continuous flow dryers, including energy saving scheme with recycling the air for cooling and for drying of grain. To determine the initial conditions at the entrance to each section of dryer the iterative process was used. The computer simulations permitted to evaluate energy efficiency of each scheme, the duration of the drying proc...

Dryer design parameters and parts specifications for an industrial scale bagasse drying system / Parámetros de diseño del secador y especificaciones de piezas para un sistema de secado de bagazo a escala industrial

Acta Agronómica, 2020

The sugar industry is an ideal sector for electricity cogeneration due to a large amount of burnable bagasse produce as a by-product. Bagasse produced in the sugar industry always consists of moisture affecting the efficiency of a boiler in the cogeneration plant. In our case study, a cogeneration plant run by bagasse burning found with bagasse moisture problem and suffocating with low power generation for the last few years. The boiler efficiency per tonne of bagasse is currently lower than optimal due to the substantial percentage of water present in the bagasse. A bagasse dryer design for this industry can improve the efficiency of a boiler as well as the cogeneration plant. In this paper, a pneumatic bagasse drying system is proposed to reduce the moisture content of bagasse from 48% to 30%. This work provides a full analysis of bagasse dryer design parameters, including specifications for dryer system components, such as feeders, fan, drying tube, and cyclone. The total bagasse...

Simulation of Recirculation Type Dryer Using Pneumatic Conveyors

Journal of Southwest Jiaotong University, 2021

Recirculating rice dryers are suitable for a large amount of loading capacity. It generally comprises two parts, the tempering section, a drying section, and the grains are dried intermittently until the final moisture content of the grains can be achieved. Wet grains are initially dried for about 11 minutes within the drying section of the dryer. The grains then are conveyed to the tempering section, stored for about 40 to 50 minutes. At every passes, about less than 2% (wb). The moisture content can be removed from the grains. The number of passes required to accomplish a drying process in a recirculation dryer depends on the initial moisture content and the amount of rough rice to be dried. The drying and tempering duration can be adjusted through a mechanical valve. The purpose of this study was to examine the performance of recirculating dryers equipped with pneumatic conveyors instead of bucket elevators to reduce electricity cost and heated using a proper blend between kerose...