A combined infrared/heat pump drying technology applied to a rotary dryer
The short drying time and low product temperature makes it suitable for drying such heat-sensitive materials as herbs and vegetables. The purpose of this work was to develop a small-scale dryer for herbs and vegetables. A prototype rotary dryer combining infrared radiation with a so-called heat pump...
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Scientific Agricultural Society of Finland
2008-12-01
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Series: | Agricultural and Food Science |
Online Access: | https://journal.fi/afs/article/view/5726 |
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doaj-b33698dc109648cf884df0d33aa219002020-11-24T23:21:12ZengScientific Agricultural Society of FinlandAgricultural and Food Science1459-60671795-18952008-12-01113 A combined infrared/heat pump drying technology applied to a rotary dryerK. PÄÄKKÖNENThe short drying time and low product temperature makes it suitable for drying such heat-sensitive materials as herbs and vegetables. The purpose of this work was to develop a small-scale dryer for herbs and vegetables. A prototype rotary dryer combining infrared radiation with a so-called heat pump drying method was applied in drying experiments for several herbs and vegetables. The drying experiments were performed under actual crop production conditions. The drying curves for leaves of birch (Betula spp.), rosebay willowherb (Epilobium angustifolium) and dandelion (Taraxacum spp.) as well as slices of red beet (Beta vulgaris) and carrot (Daucus carota) are presented. During the drying operation, temperature and humidity of the drying air were recorded, as well as the energy consumed in drying. The quality parameters measured were water content, colour and rehydration ratio. In the present rotary dryer design, intermittent irradiation and mixing of the product enable to avoid overheating, which is particularly important for maintaining product quality. In this dryer design the drying drum slowly rotates and simultaneously mixes the product. The infrared heaters are attached to a panel, allowing the product to receive infrared radiation periodically.https://journal.fi/afs/article/view/5726 |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
K. PÄÄKKÖNEN |
spellingShingle |
K. PÄÄKKÖNEN A combined infrared/heat pump drying technology applied to a rotary dryer Agricultural and Food Science |
author_facet |
K. PÄÄKKÖNEN |
author_sort |
K. PÄÄKKÖNEN |
title |
A combined infrared/heat pump drying technology applied to a rotary dryer |
title_short |
A combined infrared/heat pump drying technology applied to a rotary dryer |
title_full |
A combined infrared/heat pump drying technology applied to a rotary dryer |
title_fullStr |
A combined infrared/heat pump drying technology applied to a rotary dryer |
title_full_unstemmed |
A combined infrared/heat pump drying technology applied to a rotary dryer |
title_sort |
combined infrared/heat pump drying technology applied to a rotary dryer |
publisher |
Scientific Agricultural Society of Finland |
series |
Agricultural and Food Science |
issn |
1459-6067 1795-1895 |
publishDate |
2008-12-01 |
description |
The short drying time and low product temperature makes it suitable for drying such heat-sensitive materials as herbs and vegetables. The purpose of this work was to develop a small-scale dryer for herbs and vegetables. A prototype rotary dryer combining infrared radiation with a so-called heat pump drying method was applied in drying experiments for several herbs and vegetables. The drying experiments were performed under actual crop production conditions. The drying curves for leaves of birch (Betula spp.), rosebay willowherb (Epilobium angustifolium) and dandelion (Taraxacum spp.) as well as slices of red beet (Beta vulgaris) and carrot (Daucus carota) are presented. During the drying operation, temperature and humidity of the drying air were recorded, as well as the energy consumed in drying. The quality parameters measured were water content, colour and rehydration ratio. In the present rotary dryer design, intermittent irradiation and mixing of the product enable to avoid overheating, which is particularly important for maintaining product quality. In this dryer design the drying drum slowly rotates and simultaneously mixes the product. The infrared heaters are attached to a panel, allowing the product to receive infrared radiation periodically. |
url |
https://journal.fi/afs/article/view/5726 |
work_keys_str_mv |
AT kpaakkonen acombinedinfraredheatpumpdryingtechnologyappliedtoarotarydryer AT kpaakkonen combinedinfraredheatpumpdryingtechnologyappliedtoarotarydryer |
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