摘要:

An incineration process is routinely used in Japan to treat nearly all the generated sewage sludge. The drying process now is recognized to play an important role as a pretreatment process of a incineration process.

ISSN:0737-3937    

DOI:10.1080/07373939308916875

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

A theoretical basis for a nonlinear thermo-hydro viscoelastic boundary value problem was developed. An incremental finite element formulation was derlved using the principle of virtual work. The effects of non-uniform temparature and moisture gradients and solution dependent material property functions are outlined. An appropriate

ISSN:0737-3937    

DOI:10.1080/07373939308916876

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

An incremental finite element formulation was devdoped to simulate the viscoelastic behavior of soybean and corn Kernets during drying. Failure was predicted in a soybean kernel dried at 75°C and a corn kernel dried at 85°C, using von Mises failure criteria and experimentally determined strenglh propenies. Calculated tangential stresses

ISSN:0737-3937    

DOI:10.1080/07373939308916877

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

This paper presents a theoretical equation relating the dimensionless times of Newman's solutions of the diffusion equation for desorption and sorption. The derived equation provides a theoretical proof of the linear relationship between dimensionless time and the inverse of transport ratio for a given fraction of diffusing substance as observed numerically in the literature. Following the same approach proposed earlier by the writer, a theoretical expression for the diffusion coefficient is derived as a function of time and the inverse of desorption rate when the fraction of diffusing substance is 0.5. Evaluation of the diffusion coefficient from an experimental desorption curve is discussed.

ISSN:0737-3937    

DOI:10.1080/07373939308916878

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

The Regular Regime analysis, introduced by Schoeber in 1976, enables the determination of concentration dependent diffusivities from a single desorption experiment. A study on theoretical and practical aspects of this analysis is presented here. The theoretical background of the method is treated. Efforts have been made to simplify the calculation procedures by compacting and clarifying some complicated relationships. The calculation has become simple, straightforward and easy to use in practice. A stepwise procedure is given.

ISSN:0737-3937    

DOI:10.1080/07373939308916879

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Collapse of structure of foodstuffs during air drying affects quality. In many materials the soluble components, mainly sugars, are an important part of the tissue in which case collapse may be related to their glass transition temperature (Tg). It has been speculated that collapse occurs at a temperature (Tc) related to, but greater than, Tg. Plant tissues with high moisture contents, such as celery, have low TgS. Therefore considerable collapse is expected at drying temperatures.

ISSN:0737-3937    

DOI:10.1080/07373939308916880

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Food drying process in tunnel dryer was modeled from Keey's drying model and experimental drying curve, and optimized in operating conditions consisting of inlet airtemperature, air recycle ratio and air flow rate. Radish was chosen as a typical food material to be dried, because it has a typical drying characteristics of food and quality indexes of ascorbic acid destruction and browning in the drying. Stricter quality retention constraint required higher energy consumption in minimizing the objective function of energy consumption under constraints of dried food quality. Optimization results of cocurrent and counter current tunnel drying showed higher inlet air temperature, lower recycle ratio and higher air flow rate with shorter total drying time. Compared with cocurrent operation counter current drying used lower air temperature, lower recycle ratio and lower air flow rate, and appeared to be more efficient in energy usage. Most of consumed energy was analyzed to be used for air heating and then escape from the dryer in form of exhaust air.

ISSN:0737-3937    

DOI:10.1080/07373939308916881

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Measurement of material moisture content is necessary for the control of product quality in batch drying. However, this variable cannot be measured on-line, and state estimation techniques are proposed. A non-linear dynamic model is developed for batch drying of foods. Process disturbances and measurement errors are modeled as stochastic processes and a hybrid extended Kalman filter is employed for state estimation. This filter is based on the local linearization of the process model around the suboptimal filter estimates. The moisture estimation approach was applied to experimental points obtained in a laboratory dryer with quite satisfactory results.

ISSN:0737-3937    

DOI:10.1080/07373939308916882

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Two different methods for calculating the heat of somtion of timber are compared. One method uses thermodynamic expieasions together with the sorption equilibrium relationship given by Simpson and Rosen (1981). while the other is based on the direct measurements made by Kelsev end Clarke (1956). The latter method is most reliable for moisture contents below 0.07 kg kg-1, where the heat of sorption is significant cowered with the latent heat of vaporisstion of water.

ISSN:0737-3937    

DOI:10.1080/07373939308916883

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Two spray dryers were tested to obtain powders from concentrated juices of blackcurrant, apricot, raspberry, with different maltodextrins as drying-aid agents. Composition of fruit juices and dextrose equivalent for maltodextrin are considered. Best results were obtained for a ratio juice to maltodextrin DE6 of 65/35 for blackcurrant, of 60/40 for apricot and 55/45 for raspberry, and low air temperatures (160–90°C). A compromise must be found between the ratio fruit juice to additives, the drying yield and the cost of raw materials.

ISSN:0737-3937    

DOI:10.1080/07373939308916884

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor