Hostname: page-component-586b7cd67f-t7fkt Total loading time: 0 Render date: 2024-11-27T15:42:30.678Z Has data issue: false hasContentIssue false
  • English
  • Français

Relationship between air conditions and the drying rate of thin-layers of grass

Published online by Cambridge University Press:  27 March 2009

W. J. Lamond  and
R. Graham
W. J. Lamond
Affiliation:
Scottish Centre of Agricultural Engineering, Scottish Agricultural College, Bush Estate, Penicuik, Midlothian EH26 OPH, UK
R. Graham
Affiliation:
Scottish Centre of Agricultural Engineering, Scottish Agricultural College, Bush Estate, Penicuik, Midlothian EH26 OPH, UK
Get access Rights & Permissions [Opens in a new window]

Summary

A series of 240 thin-layer drying runs carried out in 1988 and 1989 at the Scottish Centre of Agricultural Engineering were analysed to find out which factors influenced the rate of drying of grass mixtures. The grass used in the experiments was cut by hand, by a mower without conditioner or by a mower with conditioner. The experiments covered a range of air conditions from 16·0 to 40·4 °C temperature and 24·4 to 82·8% relative humidity. By fitting curves to the experimental data it was shown that the drying curves could be simulated by a two-parameter, exponential equation. Analysis of the data showed that the experimental results could be adequately represented by holding one of the parameters fixed and fitting the curves with only one parameter varying. The variable parameter, called the drying coefficient, was dependent on harvesting method and related to drying air temperature, initial moisture content and ratio of leaf area to stem area. A regression equation relating the drying coefficient to these variables for conditioned and unconditioned grass is presented.

Predictions from the regression equations indicated that the temperature of the drying air had a major effect on the drying coefficient. Both the initial moisture content of the samples and ratio of leaf to stem had a smaller influence on the coefficient over their likely range.

Type
Crops and Soils
Information
The Journal of Agricultural Science , Volume 121 , Issue 1 , August 1993 , pp. 21 - 28
Copyright
Copyright © Cambridge University Press 1993

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Clark, R. G. (1966). An installation for crop drying research. Journal of Agricultural Engineering Research 11, 58–61.CrossRefGoogle Scholar
Dummont, A. & Park, D. (1978). Effect of barn drying on hay value. Departmental Note DN/SY/868/11007. Silsoe: National Institute of Agricultural Engineering.Google Scholar
Firth, D. R. & Leshem, Y. (1976). Water loss from cut herbage in the windrow and from isolated leaves and stems. Agricultural Meteorology 17, 261–269.CrossRefGoogle Scholar
Hale, O. D. (1986). A laboratory technique for evaluating and comparing forage conditioning mechanisms. Journal of Agricultural Engineering Research 33, 243–256.CrossRefGoogle Scholar
Harris, C. E. & Dhanoa, M. S. (1984). The drying rates of component parts of inflorescence-bearing tillers of Italian ryegrass. Grass and Forage Science 39, 271–275.CrossRefGoogle Scholar
Harris, C. E., Thaine, R. & Sarisalo, H. I. M. (1974). Effectiveness of some mechanical, thermal and chemical laboratory treatments on the drying rates of leaves and stem internodes of grass. Journal of Agricultural Science, Cambridge 83, 353–358.CrossRefGoogle Scholar
Henderson, S. M. (1952). A basic concept of equilibrium moisture. Agricultural Engineering 33, 29–32.Google Scholar
Hill, J. D., Ross, I. J. & Barfield, B. J. (1977). The use of vapour deficit to predict drying time for alfalfa hay. Transactions of ASAE 20, 372–374.CrossRefGoogle Scholar
Jones, L. (1979). The effect of stage of growth on the rate of drying cut grass at 20 °C. Grass and Forage Science 34, 139–144.CrossRefGoogle Scholar
Jones, L. & Prickett, J. (1981). The rate of water loss from cut grass of different species dried at 20 °C. Grass and Forage Science 36, 17–23.CrossRefGoogle Scholar
Lamond, W. J. (1992). Data for the calculation of the drying of grass swaths. MPhil thesis, Paisley College.Google Scholar
Lamond, W. J. & Graham, R. (1992). The relationship between air conditioning and the equilibrium moisture contents of grass. Departmental Note 50. Penicuik: Scottish Centre of Agricultural Engineering.Google Scholar
Lamond, W. J., Spencer, H. B., Graham, R. & Moore, A. B. (1989). Effect of thin layer drying rate and swath architecture on the rate of grass swath drying under controlled conditions. Journal of Agricultural Science, Cambridge 113, 59–65.CrossRefGoogle Scholar
Menzies, D. J. & O'callaghan, J. R. (1971). The effect of temperature on the drying rate of grass. Journal of Agricultural Engineering Research 16, 213–222.CrossRefGoogle Scholar
Morris, R. M. (1972). The rate of water loss from grass samples during hay-type conservation. Journal of the British Grassland Society 27, 99–105.CrossRefGoogle Scholar
O'callaghan, J. R., Menzies, D. J. & Bailey, P. H. (1971). Digital simulation of agricultural drier performance. Journal of Agricultural Engineering Research 16, 223–244.CrossRefGoogle Scholar
Page, G. (1949). Factors influencing the maximum rates of air drying shelled corn in thin-layers. MSc thesis, Purdue University.Google Scholar
Rees, D. V. H. (1974). Investigations on the drying of herbage at temperatures up to 50 °C. Journal of the British Grassland Society 29, 47–55.CrossRefGoogle Scholar
Savoie, P. & Mailhot, A. (1986). Influence of eight factors on the drying rate of timothy hay. Canadian Agricultural Engineering 28, 145–148.Google Scholar
Savoie, P., Brook, R. C. & Rotz, C. A. (1982). Empirical model for field drying of alfalfa. ASAE Paper 82–1528. St Joseph, MI, USA: ASAE.Google Scholar
Sokhansanj, S. & Cenkowski, S. (1988). Equipment and methods of thin-layer drying – a review. In Sixth Annual Drying Symposium, IDS88, Palais de Congrès, Versailles, France, 5–8 September 1988. Vol. 1. pp. 159–170.Google Scholar