Stesalit Systems Limited Tangra, Kolkata, West Bengal

Presently Tea Industry totally depends on old age technology based on batching systems for getting the tea made records which is not very reliable and huge complaint of frequent breakdowns are observed in many tea factories. TO OVERCOME this problem, Stesalit has introduced universally accepted Dynamic method for all event monitoring data of Dryer output. System Overview Stesalit Continuous Weigher (SCW) is uniquely designed for online continuous monitoring of tea made output from dryers. It is basically an electronically and sensor controlled specially designed belt weigher and can be easily placed in between dryer and sorting zone. It continuously records and displays all the events like cumulative output, total operation time, power cut time etc. This helps to monitor the productivity of the whole process at any instant. Salient Features Advantage Online display of current events like total operation time, power cut time and cumulative output Detailed event recording of individual batch for past 64 batches of all parameters with date and time Elaborate self diagnostics to detect the exact area of problems to get instant solution Easy and well defined calibration procedures for smooth and steady operation In case of power failure it starts automatically after one minute of power restoration All the parts come in contact with tea made are food grade stainless steel It can be linked with computer for remote monitoring of Stesalit Continuous Weigher (SCW) operation (optional) Different models are available from 300 kgs tea madehour to 1500 kgs tea madehour Dimension: L-1900mm x H-1200mm x W-970mm

Condition : New

During oxidization (fermenting) process the residence time of processed dhool is to be changed based on change in ambient conditions i.e. Mainly temperature and rh in all the practiced methods like floor fermentation, gumla fermentation, table fermentation and continuous fermenting machines (cfm). present practice in cfm, user can change the residence time by changing the gear ratio through connected variable drives but it is difficult to know the exact residence time at particular instant moment. to overcome from such problem, stesalit has introduced a simple solution rti (resident time indicator) for instant monitoring the residence time at any moment. system overview stesalit, one of the pioneers in micro controller based process automation and control system; proudly introduces precision â��residence time indicatorâ��, model âµrti 02. This is the outcome of extensive r&d carried out by our highly experienced and dedicated engineers at our in house state of art r&d center. in the tea industry â��residence timeâ�� of the continuous fermenting machine (cfm) plays a very important role on the final quality of tea and also to maintain the consistency in quality. Various modes of variable drives are used to set the residence time of the cfm, and there is always possibility of setting error or variation due to belt slippage voltage fluctuation etc, during operation. Considering these problems we have developed the â��âµrti 02â��, where user can see instantly the residence time display with respect to the drive setting continuously. Any unintentional erroneous change in the setting or for any other reason it can be instantly detected from the display and corrective measures can be immediately implemented. Residence time indicator rti-02 continuously monitors the rpm of the drive motor and displays the time of travel of the belt from one end to the other.

Temperature plays most critical role at all stages of tea processing starting from the plucking. Most Tea factories use Thermo-couple based sensors for Temperature monitoring and control. Thermocouple based sensor are not very accurate and temperature measurement by this method is prone to error. To overcome this, Stesalit has developed “Multichannel Temperature Scanner (MTS) a smart solution for temperature monitoring and control. Apart from highly accurate Pt-100 RTD temperature sensors, MTS also uses wireless solution to monitor the temperature remotely. It can be used anywhere like: monitoring of Dryer temperature T1, T2, T3, & T5 simultaneously in case of VFBD. It also generates online thermograph if connected with computer. ‘MTS’ are designed to meet the customized requirement. User can set lower and upper limit for desired temperature. In case of any variation in temperature from preset limits, audio- visual annunciation will become active. Salient Features Advantage • Accurate monitoring of Temperature through RTD (Pt-100) temperature sensor. • Provision for Upper and Lower limit setting of temperature.alongwith audio-visual annunciation. • Temperature data can be stored in PC and online thermograph can be obtained for analysis. • Temperature measuring range: 0°C to 250°C or as per requirement with maximum ±1° C error. • Easy installation maintenance as it is based on Wireless technology.

Stesalit has developed a highly user-friendly and version of Intelligent Tea Withering Monitoring and Control System (TWMAC) which gives uniform and consistence withered tea enhancing the quality of final tea produced. System Overview This system monitors the withering process intelligently by following the calculated weight loss profile of leaves with respect to elapsed time against a pre-set profile. For this, a sample weight of leaf is kept in a specially designed box at the same density as spread in the whole trough bed. Weights are automatically monitored in every 30 minutes of withering operation by switching OFF the fan automatically for about 4 minutes. The fan operation is controlled based on the weight loss trend at each weight monitoring interval. If the rate of weight loss (moisture removal) is lower with respect to desired weight loss, then fan will automatically switch ON and run continuously till the next weighing interval, simultaneously alarm with visual LED indication of WET condition displayed for manual hot air introduction if required. If weight loss is higher, then fan would remain switched OFF till next weighing interval with visual LED indication of DRY condition. After achieving the desired set % wither, fan will be automatically switched OFF and it will alert the user through audio visual annunciation about the completion of process. Hot air application is decided based on ambient RH and weight loss trend through audio visual annunciation. Through this, Intelligent Tea Withering Monitoring and Control System, a uniform quality of withering in tea is achieved, resulting in higher price for the final tea made. This system also saves considerable energy by monitoring the weight loss trend with respect to time and keeping the fan off when not required. The payback period for this system, in terms of energy saving alone (without considering the better realization for better quality of tea made) is less than 10 months.

Present heating practice of tea 1. The present heating practice in tea industry is to maintain pre-determined temperature of inlet and exhaust air, based on experience. But due to manual control over the three major components of the heater, e.g., id fan, fd fan & chain grate stoker according to the need, the temperature keeps on fluctuating, causing inconsistency & quality deterioration in tea made. 2. As per prevalent and commonly used practice of manual control over the heaters, more fuel as well as more electrical power than actually required is consumed for drying of tea. Consequently, the factory suffers from the detrimental effect of rise in cost of the end product. To overcome from above explained problems stesalit has introduced carc–04 to maintain the constant inlet temperature in dryer. System overview coal air ratio controller (carc-04) is a time tested and proven product at tea factories. Carc-04 offers to overcome the existing problem of inlet temperature variation due to manual operation in dryer through a close loop control system. Carc-04 maintains the combustion chamber temperature constantly by varying the speed of chain grate, fd fan and id fan precisely within the permissible level which in turn maintains the preset and preferred inlet air temperature to dryer. salient features advantage • rugged frequency drives are used with best possible protection to avoid failure due to power fluctuation • maintain constant temperature at dryer inlet (t1) results in to enhance the tea made quality consistently • minimize the production cost by optimum use of coal and electrical energy • minimize air pollution by ensuring the proper combustion of coal • reduces the heater maintenance cost • payback period for investment is around 6 months depend on manufacturing practice and coal quality one carc-04 is suitable

Present practice it is well accepted fact that relative humidity plays very important role during entire tea manufacturing at all processing zones. At present, tea planters are mainly dependent on conventional dry bulb & wet bulb thermometers and based on difference between dry bulb and wet bulb thermometers they derive the % rh from standard psychometric table. But it is very difficult to get the correct % rh since it is not possible to see the exact difference between dry bulb and wet bulb temperature in decimals and it is prone to get the erroneous %rh values resulting in taking incorrect decisions. To overcome aforesaid problem stesalit introduces the humidity management system which monitors the dry & wet bulb temperature digitally and display the % rh instantly following the standard psychometric chart. System overview microcontroller based humidity management system senses the dry & wet temperatures of air through a highly accurate intelligent state-of-art sensor and directly computes the %rh as per the embedded psychometric logic inside. The single indicator & controller module digitally displays the current %rh and the dry bulb temperature of the surrounding air. The humidity management system has in-built facilities to set the lower and upper limits for the desired %rh, along with incorporated audio-visual annunciation control mechanism in case of any variation from the pre-set % rh limits. The control output signals can also be used to automatically activate de-activate any attached electro-mechanical devices in the installed air-humidification unit to maintain the desired %rh within the preset limits.

Presently, Rotorvane Feeding is being done manually, which does not ensure even 70% accuracy in the uniformity of feed rate continuously for the whole operational period. Even combined with the highest intensity of applied supervisory control it cannot ensure the uniformity. TO OVERCOME this problem, Stesalit has designed and developed the Gravimetric Weigh Feeder (MGWF - 03) for uniform feed of withered leaves into Rotorvane. System Overview Uniform rate of feed to Rotorvane is very much important to achieve the proper preconditioning of leaf and better cut in CTC machine. Our Gravimetric Weigh Feeder (MGWF-03) is an uniquely designed equipment, to achieve this objective of uniform feed rate to Rotorvane within an accuracy limits of around 95% of the uniformity of feed rate. The irregular or uneven feeding of leaf by the workers into MGWF does not affect the uniformity of feed rate from MGWF to the Rotorvane. This results in better and uniform quality of tea made and also saving in energy and reduction in the maintenance costs of Rotorvane. The uniform feeding in Rotorvane, through MGWF, is achieved by automatically changing the conveyor�s belt speed according to the leaves fed into MGWF-03. (If leaves are fed less than the speed of conveyor will increase and if leaves are fed more, then speed of conveyor will decrease, based on preset feed rate ensuring uniform feed rate to Rotorvane. Stesalit has installed more than 500 units of MGWF-03, in many leading tea factories in India and abroad, which are working satisfactory, some of them for over 8-9 years.

Present practice at present the recovery ratio of tea made verses withered leaves is calculated based on guess work since user doesn�t know the exact information about wither % of withered leaves. To overcome this problem stesalit has introduced the frms for monitoring the all events after withering when withered leaf enters in rolling area by placing frms in existing monorail system. Features of frms 1. online display of: a. last bag weight, b. cumulative weight, c. total running hour (operational time), d. last 15 min 30 min 1 hour 2 hour cumulative weight (user setable) 2. other than above, features also available on lcd screen: a. batch no b. no of bags c. total cumulative weight (actual weight) 3. total cumulative weight for the season from the time of last master reset. 4. every detail of last 64 batches are available in history as first in first out basis. 5. built in restoration of data in case of power failure 6. use of standard 20 characters 4 line lcd display for viewing of online operation and 1 inch seven segment display for viewing of display board from distance. 7. modular construction for ease of maintenance. 8. high performance microcontroller and other components are used for better performance and ruggedness of system in real time harsh factory condition. 9. total cmos design to reduce the power consumption. 10. wireless computer interface for centralized monitoring of the monorail operation (optional at extra cost).

The present drying practice is to maintain pre-determined temperatures of dryer inlet air which does not give correct and consistent drying results during the drying process because of changing ambient air conditions (rh) during the drying process. This results in over firing or / and under firing (stewing) in final ‘made tea’ and, thus making inconsistent quality of "made tea". To overcome this existing problems of over firing or stewing of tea inside the dryer of inappropriate setting of inlet air temperature during the drying process, stesalit have successfully developed a microprocessor based electronically controlled system called ‘varun’, (idea conceived by mr. Ranjit chaliha, a distinguished tea planter) which continuously measures ambient air conditions i.e., temperature and real time humidity, through sensors and electronically computes the data and displays the correct ‘should be’ dryer inlet air temperature on real time basis during the drying process. By setting the correct temperature as displaced in ‘varun’, the tea factory can get consistent and uniformly dried ‘made tea’ without any over fire / under fire (stewing) ‘made tea’. This results in consistent and better quality of ‘made tea’ getting a better price realization of ‘made tea’. salient features / advantage • elimination of over firing or stewing of teas inside the drier. • more consistent drier output irrespective of atmospheric conditions. • maximum utilisation of potential drying capacity of inlet air. • considerable saving in fuel cost.