摘要:

Three models of the carrot drying process. were evaluated. Shrinkage during the dehydration of carrots has been found to be important. Neglecting shrinkage would produce an underestimation of the test particle moisture content. A uniform drying contraction model describes the carrot shrinkage satisfactorily. Two diffusivity models are considered. The first only takes into account air drying temperature variations and the second the particle temperature and local moisture content. Both models permit a good process description although the last allows better predictions.

ISSN:0737-3937    

DOI:10.1080/07373938908916620

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The objectives of this work are to analyze the drying performance of conical-cylindrical spouted bed (CSB) dryers for three different grains (rice, corn and wheat), and to compare the drying efficiency of CSB dryers with that of spout-fluid bed (SFB) dryers.A PC-program was developed for: (I) -optimization of the CSB dryer dimensions; (2) -simulation of drying grains in the optimized CSB dryer (including start-up period); and, (3) -analysis of the drying performance in a similar SFB dryer.

ISSN:0737-3937    

DOI:10.1080/07373938908916621

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The brown coal is wet-ground and expressed in a batch constant-pressure or constant-rate operation and in a continuous screw-press operation. It is found that 90% of the moisture of the as-mined coal can be removed under the pressure of about 100 ma. Batch operations under a constant-pressure or a con-stant-rate can be analyzed well by using the Terzaghi-Voigt model and constant-pressure analysis. In a continuous screw-press operation, the resistance of the filter medium, the feed concentration and the die resistance affect the screw performance. The volumetric discharge rate under the open discharge condition can be expressed well by a lubrication theory. With discharge restricted by a screw-type die, the slip factor decreases with increase in die resistance.

ISSN:0737-3937    

DOI:10.1080/07373938908916622

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The conditions under which a defined drying process is achieved with minimum energy supply are identified. Upon adaptation of these conditions to a drying system, a new cycling mode is proposed which leads to a heat pump design with the elements participating in the drying as working medla.

ISSN:0737-3937    

DOI:10.1080/07373938908916623

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Measurements have been made of the drying rate of thin layers of cut grass, with forced convection of air at 250c and 50% relative humidity. From measurements of the exposed surface areas of the grass and the evaporation rates measured during drying, estimates have been made of the grasses' resistance to moisture transfer.

ISSN:0737-3937    

DOI:10.1080/07373938908916624

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Numerical methods were used to study the effectiveness of superheated steam, humid air and dry air as dehydrating media in turbulent flow for the drying of wedge-shaped specimens. The Couette flow assumption was used to formulate the coupled heat and mass transfer in the turbulent boundary layer. Superheated steam was found to have highest evaporation rates at free stream temperatures above the inversion point.

ISSN:0737-3937    

DOI:10.1080/07373938908916625

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

This paper discusses the slow drying of wood chips stacked in deep beds by a flow of ambient air throughout the major part of the year. This kind of drying operation introduces some simplifications to the equation system. The celerity of the drying front is described by an analytical term, then the shape of the front is obtained by an ordinary differential equation. The meteorological data which has been put into the computer determines the progress of the drying front. The flow rate of the blower is determined from the operation characteristics (time allowed, height of the pile, moisture of the product, regulation function) and from the data of the local climate. An additional rudimentary solar collector can improve the efficiency of the system. A period of ten days will be sufficient to calculate the mean data in order to ascertain the progress of the front.

ISSN:0737-3937    

DOI:10.1080/07373938908916626

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Experimcntal studies were carried out on a multipurposc industrial solar drycr having corrugated absorber with two glass covers. Drying charactcristics of Tapioka wcre obtained on the fixed bed portion of this dryer

ISSN:0737-3937    

DOI:10.1080/07373938908916627

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

ISSN:0737-3937    

DOI:10.1080/07373938908916628

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

ISSN:0737-3937    

DOI:10.1080/07373938908916629

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor