By Uwin Lugoda
The quality of Ceylon Tea is well known throughout the world, and has made the product one of the country's biggest export items. This has given rise to a vast tea industry in the country, making it one of the best in the region.
However, industry professionals still strive to introduce more efficient and cost-effective methodologies to the manufacturing processes; the latest in these is the automation of the tea withering process.
Tea withering is considered the first and most important unit operation in a tea factory as it has a direct impact on the quality of the end product. A good-quality and precise withering process is an essential element in the processing of tea leaves as it ensures the healthy development of aroma and flavour compounds in the leaves.
However, the current process consumes 49-61% of the total electricity used by a factory, along with a lot of time and labour, the latter of which is prone to result in manual processing errors.
The Tea Research Institute of Sri Lanka (TRI) has partnered with A & T Labs to provide tea manufacturers a better option, one that not only helps save 40% of the energy consumed during the process, but also ensures optimum withering of the leaves.
"In the manufacturing of black tea, withering is considered the most important process, in order to produce good-quality black tea. This (new) automation is completely different from even what other countries are attempting. It helps the process by letting the leaves achieve optimal withering and saves energy in the process," said TRI Director Dr. Saman Hettiarachchi, speaking to The Sunday Morning Business.
These automatic tea withering controllers are set to save tea manufactures a lot of money. Research done by the TRI shows that a factory which produces 40,000 kg per month can save up to Rs. 100,0000 annually.
The project is the brainchild of the former Deputy Director – Research of the TRI, Dr. W.S. Botheju, who did his PhD on the automation of the tea withering process.
He stated that he has identified the withering process to be the most important process in tea manufacturing, as it helps reduce the moisture content of green leaves by about 55%. This process uses machinery called troughs, which use thermal energy to produce steam and electrical energy to rotate huge fans.
Dr. Botheju stated that while the cost of thermal energy is bearable for most factories, as they mostly use firewood, the cost of electrical energy is fairly high. This is because withering takes around 12-14 hours to complete.
He explained that due to this, large factories with around 24 troughs consumer really high amounts of energy, with the withering process being the highest electrical energy consumer, compared to other processes like fermentation.
In order to control the huge motors in the troughs, the TRI initially developed a device called the VSD (variable speed drive) in 2002. Dr. Botheju explained that these devices can control motors between the capacity of 5-15 horsepower, depending on the size of the troughs. This was perfect for the tea industry as most factories use motors of a 10 horsepower capacity.
The quality of Ceylon Tea is well known throughout the world, and has made the product one of the country's biggest export items. This has given rise to a vast tea industry in the country, making it one of the best in the region.
However, industry professionals still strive to introduce more efficient and cost-effective methodologies to the manufacturing processes; the latest in these is the automation of the tea withering process.
Tea withering is considered the first and most important unit operation in a tea factory as it has a direct impact on the quality of the end product. A good-quality and precise withering process is an essential element in the processing of tea leaves as it ensures the healthy development of aroma and flavour compounds in the leaves.
However, the current process consumes 49-61% of the total electricity used by a factory, along with a lot of time and labour, the latter of which is prone to result in manual processing errors.
The Tea Research Institute of Sri Lanka (TRI) has partnered with A & T Labs to provide tea manufacturers a better option, one that not only helps save 40% of the energy consumed during the process, but also ensures optimum withering of the leaves.
"In the manufacturing of black tea, withering is considered the most important process, in order to produce good-quality black tea. This (new) automation is completely different from even what other countries are attempting. It helps the process by letting the leaves achieve optimal withering and saves energy in the process," said TRI Director Dr. Saman Hettiarachchi, speaking to The Sunday Morning Business.
These automatic tea withering controllers are set to save tea manufactures a lot of money. Research done by the TRI shows that a factory which produces 40,000 kg per month can save up to Rs. 100,0000 annually.
The project is the brainchild of the former Deputy Director – Research of the TRI, Dr. W.S. Botheju, who did his PhD on the automation of the tea withering process.
He stated that he has identified the withering process to be the most important process in tea manufacturing, as it helps reduce the moisture content of green leaves by about 55%. This process uses machinery called troughs, which use thermal energy to produce steam and electrical energy to rotate huge fans.
Dr. Botheju stated that while the cost of thermal energy is bearable for most factories, as they mostly use firewood, the cost of electrical energy is fairly high. This is because withering takes around 12-14 hours to complete.
He explained that due to this, large factories with around 24 troughs consumer really high amounts of energy, with the withering process being the highest electrical energy consumer, compared to other processes like fermentation.
In order to control the huge motors in the troughs, the TRI initially developed a device called the VSD (variable speed drive) in 2002. Dr. Botheju explained that these devices can control motors between the capacity of 5-15 horsepower, depending on the size of the troughs. This was perfect for the tea industry as most factories use motors of a 10 horsepower capacity.
VSDs were able to control the speed of the fans in the troughs, depending on the extent of withering on the leaves, and according to Dr. Botheju, this drastically reduced the consumption of energy. However, these VSDs had to be operated manually, leaving room for human error.