Showing papers in "Drying Technology & Equipment in 2013"
Journal Article•
TL;DR: In this paper, Wang et al. investigated the effects of mixing ratio, thickness, temperature and velocity on thin layer drying models and established that compared with pure sludge, the addition of sawdust, layer thickness and hot air temperature have significant effects on the drying rate.
Abstract: Thin layer drying experiment of sludge, sludge and sawdust mixture were carried out to investigate the effects of mixing ratio, thickness, temperature and velocity on their drying characteristics and thin layer drying models were established. The experimental results show that compared with pure sludge, the addition of sawdust, layer thickness and hot air temperature have significant effects on the drying rate and the velocity has little effect on the drying rate. Wang-Singh model can best describe the drying process of sludge. Moisture transfer process in the drying of pure sludge, sludge and sawdust mixture can be described by Fick's diffusion equation. It was determined that the effective diffusion coefficient of dried samples of two sludge ranges from 6.13×10-6m/s~1.11×10-5m/s, 1.07×10-5m/s to1.67×10-5m/s at temperatures from 80℃ to 160℃, respectively. The activation energy was determined to be 16.67 kJ/mol for pure sludge, 2.97 kJ/mol for the mixture.
2 citations
Journal Article•
TL;DR: In this article, the main factors for low-efficiency of energy utilization in traditional grain drying and wood drying were analyzed; the energy recycling from discharging humid air is one of the main way of energy saving path for traditional drying, and there is evident energy-saving effect with common heat exchanger,heat-pump,and heat-pipe;
Abstract: The sense of urgency to energy-saving and emission-reduction,and current carbon-emission were stated in this paper.The main factors for low-efficiency of energy utilization in traditional grain drying and wood drying were analyzed;the energy recycling from discharging humid air is one of the main way of energy-saving path for traditional drying,and there is evident energy-saving effect with common heat exchanger,heat-pump,and heat-pipe;the energy-saving rate is about 12.4%with common heat-exchanger,and it is about 40%with heat-pump's utilization,it is in between the above two ways with heat-pipe's employment.The low-carbon-emission drying technologies,such as solar drying, combination drying with solar drying and heat-pump drying,hot-air and vacuum-microwave drying etc. were introduced.It is suggested that the biomass energy should replace the traditional energy supply to drying process;these measures can result in the low-carbon-emission drying.
1 citations
Journal Article•
TL;DR: In this article, the authors used nitrogen as drying medium to reduce the oxygen concentration in equipment, and the drying rate, brightness, Vc content and total phenol content of heat pump drying cantaloupe slices were studied by drying temperature, slice thickness, oxygen concentration and wind speed.
Abstract: With cantaloupe as testing material in this article, using nitrogen as drying medium to reduce the oxygen concentration in equipment, the drying rate, brightness, Vc content and total phenol content of heat pump drying cantaloupe slices were studied by drying temperature, slice thickness, oxygen concentration and wind speed. The orthogonal experiment results showed that the optimum drying process parameters are temperature-50℃, the slice thickness-5mm, oxygen volume fraction-5%. The moisture content of dried cantaloupe slice is7.42%, brightness value of L is 71.28, ascorbic acid content is 21.06 mg/100g, and total phenol content is 8.46mg/100g.
1 citations