Relationship between drying parameters and drying performance in domestic tumble dryers

2020 ◽  
Vol 90 (23-24) ◽  
pp. 2674-2689
Author(s):  
Xinchen Yu ◽  
Yi Li ◽  
Xuemei Ding
Keyword(s):  
Explanatory Power ◽  
Structure Parameters ◽  
Dimensionless Parameters ◽  
Moisture Extraction ◽  
Individual Effects ◽  
Dimensionless Variables ◽  
Pi Theorem ◽  
Tumble Dryer ◽  
Drying Efficiency ◽  
Load Size

The purpose of this study is to investigate the effect of drying parameters on drying performance in an air-vented tumble dryer, and to optimize its drying performance by adjusting parameters. The critical drying parameters that influenced specific moisture extraction rate (SMER), final moisture content, evenness of drying, and smoothness appearance were determined by the analysis of variance in JMP software, which were rotational speed of the motor and load size, with clearly significant individual effects and binary interactions. In order to improve the applicability of the outcomes obtained in this study and to take into account the interactions between drying parameters and drum structure parameters on drying efficiency, non-dimensional analysis was used and the correlation between drying efficiency and dimensionless variables was studied. The Buckingham Pi theorem was applied to the problem to derive dimensionless Pi terms upon which the drying efficiency depends. A step regression analysis was then conducted to test the assumption that SMER was influenced by the dimensionless parameters based on the standard least squares fitting. Results indicated that the regression model showed an explanatory power of 73.8%. By adjusting the dimensionless parameters in the model, an optimized energy-saving drying program was obtained with the desirability goal of reducing the value of SMER. Compared with the original program, energy efficiency was improved by 32.4%.

scholarly journals Tortuosity Index Based on Dynamic Mechanical Properties of Polyimide Foam for Aerospace Applications

Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1851 ◽  
Author(s):  
Sugeily Flores-Bonano ◽  
Juan Vargas-Martinez ◽  
Oscar Marcelo Suárez ◽  
Walter Silva-Araya
Keyword(s):  
Dynamic Compression ◽  
Dynamic Mechanical Properties ◽  
Sample Length ◽  
Fluid Viscosity ◽  
Dimensionless Parameters ◽  
Characterization Methods ◽  
Aerospace Applications ◽  
Molecular Diffusivity ◽  
Original Length ◽  
Pi Theorem

The determination of a reliable tortuosity index is lacking in the aerospace industry. Therefore, a methodology is formulated via direct and indirect characterization methods of a fluid-filled porous media. Chemical, thermal, and mechanical characterization was performed to the PolyuMACTM polyimide foam. Tortuosity was measured considering a pressure difference as the resistivity variable, rather than electrical resistivity or molecular diffusivity, as proposed on previous models. This is an empirical establishment of the tortuosity index considering the correlation among hydraulic and structural dimensionless parameters obtained through the Buckingham’s Pi theorem. The behavior of the polyimide was studied for samples of different lengths compressed at 30%, 60%, and 90% of its original length on the foaming direction. Results show that, porosity, sample length, and fluid viscosity are relevant for the insulation performance of the material. Regression analysis produced a significant statistical model fit to the data correlated from the dimensionless parameters for each dynamic compression series.

scholarly journals Similitude Analysis for Gas-Liquid-Fiber Flows in Cocurrent Bubble Columns

2006 ◽  
Author(s):  
Chengzhi Tang ◽  
Theodore J. Heindel
Keyword(s):  
Dimensionless Parameter ◽  
Bubble Column ◽  
Paper Industry ◽  
Solid Material ◽  
Pulp And Paper Industry ◽  
Gas Holdup ◽  
Bubble Columns ◽  
Force Analysis ◽  
Dimensionless Parameters ◽  
Pi Theorem

Gas-liquid-fiber systems are different from conventional gas-liquid-solid systems in that the solid material (i.e., fiber) is flexible, has a large aspect ratio, and forms flocs or networks when its mass fraction is above a critical value. With its wide application to the pulp and paper industry, it is important to investigate the hydrodynamics of gas-liquid-fiber systems. In this paper, 19 parameters that influence gas holdup in gas-liquid-fiber bubble columns are critically examined and then a dimensional analysis based on the Buckingham Pi Theorem is used to derive the dimensionless parameters governing gas-liquid-fiber bubble column hydrodynamics. Seven dimensionless parameters that are related to the fiber effects on gas holdup are further analyzed, and a single dimensionless parameter combining these dimensionless parameters is derived based on a force analysis and experimental results. This dimensionless parameter is shown to be sufficient to quantify the influence of fiber on gas holdup in gas-liquid-fiber cocurrent bubble columns. It also reduces the number of parameters needed in correlating experimental gas holdup data in gas-liquid-fiber bubble columns.

Experimentation and performance analysis of solar-assisted heat pump dryer for intermittent drying of food chips

2021 ◽  
pp. 1-35
Author(s):  
A Singh ◽  
Jahar Sarkar ◽  
Rashmi Sahoo
Keyword(s):  
Energy Efficiency ◽  
Economic Analysis ◽  
Heat Pump ◽  
Payback Period ◽  
Extraction Rate ◽  
Maximum Enhancement ◽  
Drying Time ◽  
Moisture Extraction ◽  
And Performance ◽  
Drying Efficiency

Abstract A solar-assisted heat pump dryer is fabricated for intermittent drying. The experiment is performed for different intermittency ratios for radish drying using future refrigerant R1234yf. The effects of total drying time (on-period + off-period) on various energetic, exergetic, and economic performances are investigated. Radish chips were dried to extract moisture from 92.4% to 11.9%. Energy efficiency and drying efficiency are estimated higher for a lower intermittency ratio. The moisture extraction rate and specific moisture extraction rate are higher for intermittent drying as compared to continuous drying and increase with a decrease in intermittency ratio. The economic analysis concludes that the payback period is lower for a lower intermittency ratio. The payback period for intermittency ratio of 1, 0.66, 0.33 and 0.2 are estimated as 1.617 years, 1.459 years, 1.384 years, and 1.347 years, respectively. Present experimental thermo-economic analysis reveals that intermittent drying is much better (maximum enhancement of specific moisture extraction rate is 60.6%, that of energy efficiency is 56.4% and maximum reduction of drying cost is 37.9% with studied conditions) than continuous drying.

A Dimensional Analysis of Ex-Vessel Steam Explosion

2018 ◽  
Author(s):  
Li Wei ◽  
Guo Qiang ◽  
Yuan Yidan
Keyword(s):  
Data Mining ◽  
Dimensional Analysis ◽  
Steam Explosion ◽  
Nuclear Power ◽  
Power Plants ◽  
Severe Accident ◽  
Dimensionless Parameters ◽  
Experimental Facilities ◽  
Pi Theorem ◽  
Experimental Findings

This paper presents a dimensional analysis for ex-vessel steam explosion occurring in a severe accident of nuclear power plants. Some dimensionless parameters were obtained from this analysis through Buckingham’s PI theorem. These dimensionless parameters are not only helpful to design experimental facilities and testing parameters, but also useful to categorize the experimental findings into uniform forms which facilitate data mining for in-depth understanding and generalization.

Investigation of Yarn Twist Propagation in Rotor Spinning

2002 ◽  
Author(s):  
BinGang Xu ◽  
XiaoMing Tao
Keyword(s):  
Dynamic Equilibrium ◽  
Dynamic Coupling ◽  
Coupling Effects ◽  
Forming Process ◽  
Dimensionless Parameters ◽  
Yarn Tension ◽  
Rotor Spinning ◽  
Yarn Twist ◽  
Mechanical Approach ◽  
Dimensionless Variables

This paper proposed an integrated mechanical approach for yarn dynamics in rotor spinning, especially the twist propagation in the yarn forming process from fibers collected in a rotor groove to the twisted yarn at the twist stopper. Equations of dynamic equilibrium in different yarn forming regions were established, and further, expressed in terms of dimensionless variables. Then the yarn tension and twist distribution, considering the dynamic coupling effects between different regions under the steady spinning conditions, were numerically simulated, in which influences of various dimensionless parameters of rotor spinning on the yarn tension and twist distributions were discussed in details.

scholarly journals A note on “simplification and scaling”

1976 ◽  
Vol 20 (1) ◽  
pp. 63-67 ◽  
Author(s):  
N. Riley
Keyword(s):  
Relative Size ◽  
Dimensionless Parameters ◽  
The Core ◽  
Applied Mathematician ◽  
Dimensionless Variables

In a recent paper Segel (1) points out that the diverse techniques (which “comprise the core of the applied mathematicians art (or craft)”) of the applied mathematician, although in general reliably proven, are “rarely explicitly delineated but rather are transmitted indirectly and informally”. In his article Segel aims to clarify two such techniques, namely:(i) Scaling—or how to choose dimensionless variables in such a way that the relative size of the various terms in an equation is explicitly indicated by the magnitudes of the dimensionless parameters which precede them,(ii) Simplification—a procedure in which a term is neglected under the assumption that it is small, and the consistency of the assumption checked later.

The Explanatory Power of Ethnomethodology

1980 ◽  
Vol 25 (7) ◽  
pp. 573-574
Author(s):  
JAMES LULL
Keyword(s):  
Explanatory Power

The Explanatory Power and Status of Power and Status

1979 ◽  
Vol 24 (10) ◽  
pp. 748-750
Author(s):  
K. T. STRONGMAN
Keyword(s):  
Explanatory Power

Comparison of Examinees’ and Doctors’ Judgement of Health Status Using Data in an AMHTS

1984 ◽  
Vol 23 (01) ◽  
pp. 15-22
Author(s):  
Y. Sekita ◽  
T. Ohta ◽  
M. Inoue ◽  
H. Takeda
Keyword(s):  
Health Status ◽  
Discriminant Analysis ◽  
Explanatory Power ◽  
Laboratory Data ◽  
Subjective Symptom ◽  
Health Conditions ◽  
Testing System ◽  
Multiple Discriminant Analysis ◽  
Canonical Axis ◽  
Using Data

SummaryJudgements of examinees’ health status by doctors and by the examinees themselves are compared applying multiple discriminant analysis. The doctors’ judgements of the examinees’ health status are studied comparatively using laboratory data and the examinees’ subjective symptom data.This data was obtained in an Automated Multiphasic Health Testing System. We discuss the health conditions which are significant for the judgement of doctors about the examinees. The results show that the explanatory power, when using subjective symptom data, is fair in the case of the doctors’ judgement. We found common variables, such as nervousness, lack of perseverance etc., which form the first canonical axis.

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