Firewood energy utilization in different dryers used in Tea processing
No Thumbnail Available
Date
2015
Journal Title
Journal ISSN
Volume Title
Publisher
Uva Wellassa University of Sri Lanka
Abstract
Tea industry is one of the most key important drives in Sri Lankan economy. Sri Lanka Sustainable
Energy Authority is one of the important government institutions for energy management and
enhancing awareness and creating technical capacity on energy conservation in Sri Lanka. Tea
industry utilizes both electrical and thermal energy for its processing. The tea factories pre-
dominantly use fuel wood to meet their thermal energy needs, in the drying process, which is the
major transformation process in the tea industry. The lack of researchers on the energy utilization of
different dryers used in Sri Lankan tea industry and different types of dryers are used depending on
the production capacity of the tea factory.
The objectives of the research are to find out firewood energy utilization of different dryers and
performance of different dryers in Sri Lanka.
Materials and methodology
The research was carried out to Sustainable Energy Authority during the period from April to August
2014. Specific thermal energy utilization (MJ/kg) was used to measure the level of firewood
consumption for dryers and it was tested for different dryers, location and combustion technology.
Two factor factorial design was implemented as the experimental design where dryer type and
combustion technology were taken in to consideration .There are three types of dryer commonly used
in tea drying such as, conventional endless chain pressure type dryer (ECP), Fluidized bed drier
(FBD), and combination drier which works on a combination of ECP and FBD principles .There are
two types of combustion technologies used for tea drying such as, Boilers and furnace. Primary data
were collected from factory officers by providing the structural questionnaires. Secondary data were
also collected from the annual reports of Sri Lanka Sustainable Energy Authority and factory reports
of different tea factories. Collected sample was surveyed based on the factory records during 2012 to
2013 to gather necessary information. Factory observations were also was carried out to confirm the
accuracy of data that were collected by the interviews of factory officers and Factory managers.
Minitab 16 Statistical Software was used for both descriptive and interferential statistics. ANOVA
General linear model was used to analyze the variance of dryer output in relation to dryer types and
combustion technology. Collected data were analyzed using descriptive statistical methods.
Descriptive statistics were graphical explained with using of Microsoft Excel and Minitab software.
Pearson correlation was used to determine the association of consumption of firewood and total
production. The relationship of firewood consumption and total production were analyzed by using
simple regression technique.
Results and Discussion
According to descriptive statistics, firewood Energy Source was highly used in tea processing. The
result revealed that, 19% firewood and saw dust, 8% firewood and furnace oil, only 3% of firewood and coconut shell was also used. Jungle wood was highly used in tea processing. The results showed
that 36% rubber firewood and only 19% rubber and jungle wood were also reported.
The low country and mid country tea factories use only firewood and saw dust. But up country tea
factories use different types of energy sources. Up country tea factories mainly use Fluidized Bed
dryers and mid country and low country highly use Endless Chain Pressure dryers. Low country and
up country mainly trended in small scale production and mid country highly trended in large scale
production. In mid country, it is available large, medium and low price firewood. But in up country
and low country, it is available only large and medium price fire wood.
The Endless Chain Pressure dryer was the highly used dryer type.it was revealed that, 28% of
Fluidized Bed dryers and only 25% of combination dryers were also used in tea processing. Endless
Chain Pressure dryers had the dryer capacity of 180-280 kg/hr, Fluidized Bed dryers had 280-500
kg/hr and Combination dryers had 250-450 kg/hr capacity. Endless Chain pressure Dryers are easy
to be maintained than others. Endless Chain Pressure dryers were mainly used in small scale
production, Fluidized Bed dryer and Combination dryers were highly used in large scale production
in tea factories.
The furnace combustion technology was highly used in tea processing. 61% furnace and only 39 %
of boilers were reported. Majority of tea factories in small scale production use furnace and tea
factories in large scale production use boilers. Majority of low country and mid country tea factories
use furnaces and up country tea factories use boilers and prominently Endless Chain Pressure dryers
utilize the energy of furnace and Fluidized Bed dryers use the energy of boilers.
When consider the Regression output, P value 0.000 of the model suggests that at 5% significant
level, firewood consumption is significant in relation to the dryer made tea production. R – Square
was recorded as 49.3 % and it implies that 49.3% of the firewood consumption is explained by the
made tea while the 50.7% is explained by unexplained variables.
Description
Keywords
Agriculture, Export Agriculture, Power System, Tea Industrials, Tea Technology, Energy