CONTINUOUS CHEMICAL WITHERING MACHINE

FIELD OF INVENTION
[001] The embodiments herein generally relate to a withering machine  specifically a continuous chemical withering machine for efficiently withering tea leaves without much manual interference. More specifically  embodiments described herein relate to a continuous withering machine that helps in the chemical wither of tea leaves and which facilitates even discharge of the tea leaves from the machine.

BACKGROUND OF THE INVENTION
[002] One of the most important procedures for producing good quality tea is withering the tea leaves in a proper fashion. It will not be wrong to deem it the most important step in producing quality teas as a slight change in the withering of the leaves result in changes in the tea quality. Withering involves changing the physical and chemical properties of the leaves and the process of natural withering starts immediately after the leaves are plucked. Therefore  leaves are transported in an efficient  quick way so as to reach factory without being damaged.
[003] Withering can be divided into two kinds depending on the type of change that the leaves undergo  namely  physical and chemical. In physical withering  the moisture content is reduced whereas in chemical withering various bio-chemical changes take place in the leaf. Whereas physical withering is important for fermentation  chemical withering is important for flavor. Usually  physical withering takes two to four hours to complete. During physical withering  hot air is blown on the leaves to reduce the moisture content and wither it faster. Chemical withering takes longer time to complete and the process cannot be hastened without compromising on the quality of tea. It takes around four to eighteen hrs for a chemical wither  depending on the weather conditions  wherein leaves are evenly spread and placed in troughs and fans are used to control the temperature of the air blown.
[004] Chemical withering is a function of time and temperature. In chemical withering  the leaves must be spread evenly to let the air circulate freely. To circulate the air freely through the leaves  in the prior art  fans and blowers of various construction have been used to blow air on the leaves and efficiently control withering. Air is usually blown either intermittently or continuously at low flow rates through the leaves to keep it cool without losing the moisture. These fans and blowers are still used in the process  except nowadays  individual fans and blowers are used to circulate the air as well as to evaporate it. However  most of these fans have to be manually operated. Since different types of tea leaves  depending on the weather conditions  require different time for withering  the circulating air must also be controlled accordingly. Also  since the air sometimes need to be blown intermittently  continuous supervision and manual operation is required. Mechanical fans require supervision to turn it on and off intermittently. Moreover  in the conventional open trough  fans are fitted at the inlet or below the trough bed. Their positioning is such that they do not provide efficient blowing of air.
[005] Also  as mentioned hereinbefore  for efficient withering of the leaves  the leaves need to be spread evenly. It is understood that since chemical withering of the tea leaves is a delicate process wherein various bio-chemical changes occur in the leaves  physical handling and spreading of the tea leaves might subject it to damage resulting in poor quality tea. Earlier  the leaves were spread manually which may result in inferior quality teas. In later years  spreaders of different construction were used but they either spread the leaves inefficiently or damage the leaves.
[006] In the most conventional troughs  leaves are loaded unto the open trough and are manually spread as evenly as possible. This method is inefficient; not only does it use manual intervention that may damage the leaves; it cannot be ensured that the spreading of the tea leaves is even every time. In some troughs facilitating continuous withering  the leaves are loaded in the trough through conveyor belts  but this method also requires human supervision as there are chances of uneven loading of the leaves on the conveyor belt. In other troughs  spreaders of various kinds are used to spread the leaves before they are loaded unto the conveyor belts of the trough. However  if the speed at which the spreader operates is not in tune with the speed at which the conveyor belt moves there might be places wherein tea leaves are more densely or sparsely distributed  thus leading to an uneven spread.
[007] As mentioned hereinbefore  many troughs these days have conveyor belts for easy transport of the leaves from one place to another. These conveyor belts also help in removing the leaves from the trough after the withering is over. Since chemical withering is a long process that requires hours to complete  the conveyor moves at a slow speed and discharges the leaves. However  in most of the prior arts  while discharging the leaves  the mechanism used is such that the leaves are not evenly discharged. Either the topmost leaves or the bottom-most leaves are discharged sooner than the rest of the leaves  thus exposing the rest of the already withered leaves to further wither which may be detrimental to the quality of tea.
[008] Thus  there is a need in the art to provide a continues chemical withering machine along with a trough that would provide a blowing mechanism by which air can be distributed evenly throughout the trough  the time for the operation of the fans can be automatically controlled and most importantly  the leaves may be evenly spread without any human intervention or fear of damage and can also be discharged evenly thus not exposing the leaves to further withering than required.

OBJECTS OF THE INVENTION
[009] A main object of the invention is to provide a chemical withering machine for withering tea leaves.
[0010] Another object of the invention is to provide a continuous chemical withering machine that would continuously wither tea leaves.
[0011] Yet another object of the invention is to provide fans with blowers in a manner that would facilitate even circulation of air in the open trough.
[0012] Another object of the invention is to provide fans and blowers that can be automatically operated such that no supervision is required.
[0013] Further object of the invention is to provide a feeding doffer to spread the tea leaves efficiently without any human intervention and in a manner that would prevent damage of the leaves.
[0014] Another object of the invention is to provide a feeding doffer mechanism such that the leaves are evenly spread in the open trough.
[0015] Yet another object of the invention is to provide for a discharging doffer that would facilitate even discharge of the tea leaves.
[0016] The other objects and advantages of the present invention will be apparent from the following description when read in conjunction with the accompanying drawings which are incorporated for illustration of preferred embodiments of the present invention and are not intended to limit the scope thereof.

SUMMARY OF THE INVENTION
[0017] In view of the foregoing  an embodiment herein provides a continuous chemical withering machine for withering tea leaves which can  among other things  spread the tea leaves more efficiently without any damage or human intervention and can also discharge the leaves evenly thus not exposing some portions of the spread to further withering than required.
[0018] According an embodiment  the chemical withering machine includes atleast a shuttling conveyor belt platform that can move back and forth on the guiding rails of an open trough  atleast a feeding doffer on both the end of shuttling conveyor belt  a trough having floor wherein air chamber below the floor is divided into a number of separate air chambers wherein blowers with dampers are placed for adequate air circulation  atleast a meshed conveyor belt placed above the air chamber and throughout the entire length of the trough that transports the leaves  and atleast a discharge doffer that helps in discharging the appropriately withered leaves in an even manner.
[0019] In an embodiment of the present invention  tea leaves are loaded onto the shuttling conveyor belt provided at the top of the trough. The shuttling conveyor belt platform can move the length of the trough. Further  the conveyor belt can start moving towards one of the feeding doffers and brings the tea leaves towards the feeding doffer. In an embodiment  the feeding doffer includes a motor  a suitably designed rotating mechanism having plurality of blades  wherein the blades are configured to spread the leaves as soon as the leaves come in contact with the doffer. Thus  the leaves are spread without damage and without human intervention.
[0020] Once the leaves are thus loaded on the mesh conveyor belt of the open trough  the blowers with dampers start circulating the air freely through the tea leaves. According to present invention  the arrangement of the blowers with dampers in separate air chambers closely adjacent to one another enables better and uniform air circulation inside the trough. These blowers with dampers can be set to operate automatically with respect to specified set-time and intervals. In an embodiment  individual blowers with dampers can also be operated separately. In another embodiment  all the individual blowers with dampers can be automatically operated. Therefore  air can be circulated automatically  both intermittently and continuously  by setting the operating time of the blowers with dampers.
[0021] Once the leaves are appropriately withered  they are moved to the discharge doffer with the help of the mesh conveyor belt. The discharge doffer helps in discharging the tea leaves in an even manner such that uneven-withering of some portion can be avoided.
[0022] These and other aspects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood  however  that the following descriptions  while indicating preferred embodiments and numerous specific details thereof  are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof  and the embodiments herein include all such modifications.

BRIEF DESCRIPTION OF THE DRAWINGS
[0023] The detailed description is set forth with reference to the accompanying figures. In the figures  the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The use of the same reference numbers in different figures indicates similar or identical items.
[0024] Fig 1 illustrates the general view of the continuous chemical withering machine  according to an embodiment herein;
[0025] Fig 1a illustrates the feeding doffer used for feeding and spreading the tea leaves inside the trough  according to an embodiment herein;
[0026] Fig 2 illustrates the sectional view of the continuous chemical withering machine  according to an embodiment herein;
[0027] Fig 3 illustrates the air circulation through the trough by a blower with damper  according to an embodiment herein;
[0028] Fig 4 illustrates the isometric view of the discharge doffer to discharge the tea leaves from the trough  according to an embodiment herein; and
[0029] Fig 5 illustrates the sectional view of the discharge doffer provided in the chemical withering machine  according to an embodiment herein.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0030] The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly  the examples should not be construed as limiting the scope of the embodiments herein
[0031] As mentioned  there is a need in the art to provide a continuous chemical withering machine that would facilitate even spreading of the tea leaves when the leaves are loaded unto the trough as well as even discharging of the leaves when it leaves the trough. Referring now to the drawings  and more particularly to FIGS. 1 through 5  where similar reference characters denote corresponding features consistently throughout the figures  preferred embodiments are shown herein.
[0032] Fig. 1 illustrates a general view of the continuous chemical withering machine 100 [herein after also referred as [CCW] along with its various parts  according to an embodiment. Accordingly  the CCW includes an open trough 101  which is a rectangular  narrow box with an open top. At the top of the open trough  a shuttling conveyor 102 with atleast a feeding doffer 103 on both ends is provided. This shuttling conveyor 102 can move from one end of the trough 101 to the other with the help of conveyor wheels 104 on the guided rails provided at the sides of the trough 101. The bottom of the trough has a conveyor belt 105 which is made of special mesh  according to an embodiment. Underneath the conveyor belt 105  blowers with dampers 106 are provided in a manner that facilitates even circulation of air throughout the trough 101. A discharge doffer 107 is provided at one end of the trough to discharge the tea leaves from the trough 101.
[0033] When tea leaves are loaded onto the shuttling conveyor belt 105  they are efficiently and evenly spread into the trough 101 with the help of the shuttling conveyor 102 and the feeding doffers 103. The shuttling conveyor 102 may be half of the length of the trough 101 and can be moved from one end of the trough 101 to the other with the help of the conveyor wheels 104 and the guided rails provided at both sides of the trough 101. After the leaves are loaded  the shuttling conveyor belt 108 starts moving slowly from one end of the trough 101 to the other. As the entire shuttling platform 102 guided by the rails starts moving from one end to another  the shutting conveyor belt 108 also starts moving towards one of the doffers 103. As the tea leaves come in contact with the feeding doffer 103  it starts operating and spreading the tea leaves unto the open trough 101 until the shuttling platform 102 reaches the one end of the trough 101. At this position  tea leaves would be distributed in one-half of the trough 101. Now  the platform 102 now starts moving from the current position to the other end of the trough 101. The conveyor belt 108 starts rotating in the opposite direction and the doffer 103 at the other end starts spreading the leaves until the conveyor 102 reaches the other end of the trough 101. According to an embodiment  the movement of the shuttling platform 102 is always from one end of the trough 101 to the other and back to the start. In this way  tea leaves are evenly distributed in the entire trough 101.
[0034] It must be noted that the rotation of the conveyor belt 108 and the operation of the doffers 103 correspond to the directional movement of the conveyor platform 102. For example  while the guided rails move the shuttling platform 102 slowly from the one end to the another end of the trough  the conveyor belt 108 might start moving in backward direction and the left doffer 103L would start spreading the leaves. Because of this movement  the trough 101 would be filled from the left to its middle. Once the shuttling platform 102 reaches to another end  the shuttling platform 102 starts moving to from another end to one end of the trough  thereafter the conveyor belt 108 might start moving in forward direction and the right doffer 103R starts spreading the leaves. During spreading through right doffer 103R  the shuttling platform 102 starts moving slowly from one end to another end of the trough. Thus  leaves are filled from the middle of the trough 101 to the right end. In this way leaves are distributed evenly in the trough 101.
[0035] It is not necessary that the platform 102 should move from left to right direction only. It can also move in a backward direction and fill the trough 101 accordingly. Therefore  the movement of the conveyor belt 108 and the manner it fills the trough 101 can be controlled as desired.
[0036] Operation of the Feeding Doffers: According to an embodiment  atleast a doffer 103 is present at each end of the shuttling conveyor belt 108. The doffer 103 can help in spreading the tea leaves evenly without damaging the same. In an embodiment  the doffer 103 includes a motor 111 and a designed rotating mechanism 112 having plurality of blades 113  wherein the blades are configured to spread the leaves as soon as the leaves come in contact with the doffer as illustrated in Fig 1a. The rotating mechanism 112 is placed just below the shuttling conveyor belt 108  and rotates at a predetermined speed. The rotation speed of the mechanism 112 is synchronized with the movement speed of the conveyor belt 108. The leaves coming out from the conveyor belt 108 falls over the blades 113 of mechanism  thereby the leaves are evenly spread across the width of the trough 101.
[0037] Operation of the shuttling platform and the belt: In an embodiment  the shuttling platform 102 is provided with a conveyor belt 108 around it. Beneath each end of the conveyor belt 108 is provided with a pair of wheels 104. These two pairs of wheels 104 on two ends of the shuttling platform 102 are placed on the guiding rails provided at both sides of the trough 101. The guided rails are provided along the length of the trough 101 to support the shuttling platform 102 and move it from one end of the trough 101 to the other. Also  the movement of the conveyor belt can be controlled with the help of the motor.
[0038] Mechanism for Chemical Withering: According to an embodiment  after the leaves are evenly spread in the trough 101 by the shuttling conveyor 102  the blower with damper 106 starts to circulate the air through the tea leaves. The conveyor belt 105 on which the leaves are spread is made of a mesh and the blowers with dampers 106 are provided underneath the mesh 105. These fans (blowers with dampers) 106 help in circulating the air as well as evaporating the surface moisture. Chemical withering takes around eight to fourteen hours  depending on the weather conditions. When the trough is loaded with the first batch of leaves  the fans start blowing and damping the air  withering the leaves. After the leaves are withered for the required number of hours  the conveyor belt 105 starts moving towards the discharge doffer 107 situated at one end of the trough 101 and the leaves get discharged. It must be noted that the conveyor belt 105 does not move when the first batch of tea leaves are withered  after which the conveyor belt receives the tea leaves from the shuttling conveyor continuously and moves at a continuous slow pace to discharge the leaves continuously.
[0039] Construction of the Trough: According to an embodiment  the trough 101 is a rectangular  narrow box with an open top as illustrated in Fig 2. The air chamber of the trough 101 is divided into a number of separate air chambers 201 at its bottom and each chamber is fitted with a blower with damper 106. Such a placement of the fans 106 provide equal circulation of air through the tea leaves  as illustrated in Fig 4. As the duration of chemical withering differs according to the kind of tea leaves and the weather  accordingly  at times  air needs to be blown intermittently or continuously for different lengths of time. To facilitate the blowing of air without external supervision  these fans 106 of the present embodiment are provided with automatic controller wherein the hours for which the fans need to operate and the intervals are pre-selected. Above the air chamber 201  a special mesh conveyor belt 105 runs through the entire length of the trough 101. Tea leaves are loaded onto this mesh conveyor belt 105. As illustrated in Fig 4  when the fans 106 operate  air is blown through the air chambers 201 and travels through the perforations in the conveyer belt 105 to circulate freely through the tea leaves. As illustrated in Fig 2  the conveyer belt 105 operates with the help of drive rollers 202  idler rollers 203 and a main conveyor drive with AC Variator 110. With the help of the AC Variator  the speed of the conveyor belt can be controlled. When the main conveyor drive 110 rotates  the conveyor belt 105 starts moving on the drive rollers 202. The idler rollers 203 help in the smooth movement of the conveyor mesh belt 105.
[0040] Mechanism of the Discharge Doffer: At one end of the trough 101  a discharge doffer 107 is provided for discharging the withered tea leaves  according to an embodiment. The isometric view and sectional view of the discharge doffer is illustrated in Fig 5 and Fig 6. As can be seen from Fig 6  the discharge doffer 107 includes one or more plates 501 and plurality of rollers 502. The two parallel rows of rollers 502 are present on each side of the doffer 107 and arranged in a zig-zag manner. The three plates 501 are placed in between the parallel rows of rollers 502 and these plates 501 are placed in a downward slope for easy discharge of the tea leaves. At both ends of the discharge doffer 107  roller mechanisms 503 are provided. The roller mechanism is illustrated in the isometric view in Fig 5  according to an embodiment. Each roller mechanism 503 consists of a pair of toothed wheel 504  one at the top and another at the bottom. Further  a chain 505 is mounted on these toothed wheels 504  and the wheels 504 move with the help of a motor (not shown). This roller mechanism 503 is in touch with the rollers 502 of the doffer 107 and they move in tandem with the movement of the wheels 504. Therefore  when the roller mechanism 503 starts operating  the rollers 502 of the discharge doffer 107 start rotating at the same speed. When the conveyor belt 105 moves the tea leaves near the discharge doffer 107  the rotation of the rollers 502 allows the leaves gently to fall down/discharge. In this way  the leaves are evenly discharged from the trough.
[0041] Operation of the Machine: For the withering of tea leaves  the leaves are loaded on the shuttling conveyor belt 108. After the leaves are loaded  the conveyor belt 102 with the help of a motor starts moving from one end of the trough 101 to the other with the help of the wheels 104 placed on the guiding rails. Simultaneously  the shuttling conveyor belt 108 also starts moving and thus moves the leaves towards one of the doffer 103. The doffer 103 starts operating at the same time when the platform 109 starts to move. As and when leaves come in contact with the doffer 103  it spreads them with the help of a rotor 111. The movement of the rotor 111 facilitates the spreading the tea leaves without any damage and with no manual intervention. These leaves fall in the mesh conveyor belt 105 of the trough 101 after being spread by the doffer.
[0042] As the leaves get loaded on the mesh conveyor belt 105  the blowers with damper 106 provided at the bottom of the trough starts to blow air as well as evaporate it  thus the temperature of the leaf is controlled. The trough 101 is divided into a number of air chambers 201 at the bottom wherein blowers with dampers 106 are placed. These blowers with dampers 106 blow air upwards towards the tea leaves placed on the mesh conveyor belt 105  thus circulating the air freely through the tea leaves. The blowers with dampers 106 can be automatically operated such that they can be switched on or off and at regular intervals automatically without any human interference. Depending on the weather conditions and the time required for an appropriate wither  the time and intervals for the blowers with dampers 106 can be set to operate automatically. Once the leaves are completed the desired duration  they are moved by the conveyor belt 105 and taken to the discharge doffer 107. The discharge doffer 107 helps in discharging the tea leaves evenly. The discharge doffer mechanism consists of rollers 502 placed in two parallel rows in a zig-zag manner and a number of discharge plates 501 placed in between the rows of rollers 502. These plates 501 slope downwards for easy discharge of the leaves. The rollers 502 are in contact with a roller mechanism 503 provided at both sides of the discharge doffer 107 consisting of a pair of toothed wheels 504 at the top and at the bottom and a chain 505 mounted on the pair of wheels 504. When the roller mechanism 503 starts moving with the help of the motor  the rollers 502 of the discharge doffer 107 which are in touch with the roller mechanism also starts rotating at the same speed. As the tea leaves touch the rotating rollers 502 of the discharge doffer 107  they are gently released because of this rotating motion. When they reach the discharge plate 501  the slope of the plate 501 helps in easy discharge of the leaves. In this manner  the tea leaves are evenly discharged with the help of the discharge doffer 107.
[0043] In an embodiment of the present invention  each of the blowers with dampers can be individually controlled. Hence  if a portion of the spread requires more air  the same can be provided by operating the blowers with dampers placed underneath that portion.
[0044] Also  in another embodiment of the present invention  there is provision for each blower with damper to be automatically controlled by setting a specified duration of operation.
[0045] In an embodiment of the present invention  the rotation of the rotors on the spreading doffer may be controlled with the help of motors and the like.
[0046] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can  by applying current knowledge  readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept  and  therefore  such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore  while the embodiments herein have been described in terms of preferred embodiments  those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.
Abstract
In view of the foregoing  an embodiment herein provides a continuous chemical withering machine includes atleast a shuttling conveyor belt platform that can move back and forth on the guiding rails of an open trough  atleast one feeding doffer at the end of the shuttling conveyor belt  and the air chamber below the floor is divided into a number of separate air chambers wherein blowers with dampers are placed for adequate air circulation  a meshed conveyor belt placed above the air chamber and throughout the entire length of the trough that transports the leaves  and a discharge doffer that helps in discharging the appropriately withered leaves in an even manner such that no portion of the appropriately withered leaves are exposed to more wither than necessary.

I Claim:
1. A continuous chemical withering machine comprises of:
a trough having long narrow open container for storing tea leaves;
atleast a shuttling platform placed over the trough;
a shuttling conveyor belt placed in the shutting platform;
atleast a feeding doffer at both the end of shuttling conveyor belt; and
atleast a discharge doffer placed at one end of the trough.
2. The continuous chemical withering machine of claim 1  wherein said trough is divided in to plurality of air chambers at its bottom end.
3. The continuous chemical withering machine of claim 2 further comprises of plurality of blower with chamber provided below at said air chambers.
4. The continuous chemical withering machine of claim 1 further comprises of a pair of guiding rails at both side along the length of said trough; and a pair of wheels placed on the guided rails provided below said shuttling platform.
5. The continuous chemical withering machine of claim 4  wherein said shutting platform can move from one end to another end of the trough.
6. The continuous chemical withering machine of claim 1  wherein said shuttling conveyor belt can move in forward or backward direction.
7. The continuous chemical withering machine of claim 1  wherein said feeding doffer comprising of a motor and a suitably designed rotating mechanism  wherein said rotating mechanism includes plurality of blades.
8. The continuous chemical withering machine of claim 7  wherein said blades are configured to spread the tea leaves across the width of said trough.
9. The continuous chemical withering machine of claim 1  wherein said discharge doffer includes one or more plates  plurality of rollers  a pair of roller mechanism placed at both side of discharge doffer  a toothed wheel placed over each roller mechanism  and a pair of chain mounted on toothed wheels provided at both side.
10. The continuous chemical withering machine of claim 9  wherein said pair of chain is connected to said rollers.
11. The continuous chemical withering machine of claim 9  wherein said roller mechanism can rotate for rotating said chains at predetermined speed.
12. The continuous chemical withering machine of claim 9  wherein said rotation of chain enables to rotate said rollers across outer diameter of the discharge doffer.