Present disclosure generally relates to a sugar hopper. More particularly relates to
a sugar dryer which provides wave motion to sugar crystals during travel on a
conveyor of the sugar dryer. The wave motion ensures proper exposing of all layers
of sugar crystals to ambient and thereby ensuring cooling 5 during the travel.
BACKGROUND OF THE INVENTION
Conventionally there are two types of sugar dryer. Fluidized bed dryer with
vibrating perforated bed. This consist of a high speed motor, which is connected
10 with an eccentric shaft usually runs at a speed of 300 – 400 strokes per minute. This
creates oscillating motion of the bed, which makes the wet sugar to travel forward
and dry air is supplied below the perforated bed. The air will take away the moisture
from the wet sugar.
15 Yet another conventional sugar dryer is a fluidized bed dryer with stationary bed.
In this sugar travel along with the flow of air on stationary perforated bed by the
virtue of fluidization.
The aforesaid two types of sugar dryers have the following issues and limitations.
20
The conventional type dryers as discussed above will lack in positive motion. For
travel description in the fluidized bed dryer with vibrating perforated bed is based
on vibration and inertia forces, and while for the fluidized bed dryer with stationary
bed depends on air direction. The aforesaid type of dryers depends on the quality
25 of inlet wet sugar.
Further, the color of sugar crystal is gets on undesirable higher side due to the
friction of the crystal, undesirable sugar dust escapes into the surrounding for the
fluidized bed dryer with vibrating perforated bed. The sugar dust escapes through
30 the clearance provided between stationary and vibrating parts.
As high speed motor is installed for vibrating conveyor, more care and frequent
maintenance is required for bearing and eccentric shaft for fluidized bed dryer with
3
vibrating perforated bed. In addition, for the fluidized bed dryer with stationary bed
large capacity, high speed fan/blowers are required to make sugar crystal travel as
well as drying, all these rotating machine required huge initial investment and high
maintenance.
5
The aforesaid fluidized bed dryers will have limitation on different inlet sugar feed
condition / quality. Excess moisture in sugar creates problems in the dryer /
conveyor.
10 Present invention is directed to overcome the shortcoming of the existing designs
of the fluidized bed dryers.
SUMMARY OF THE DISCLOSURE
The main objective of the present disclosure is to provide a sugar dryer which can
15 add wave motion of sugar crystal during travel, which is a positive motion. This
motion ensures proper exposing of all layers of sugar to ambient and ensure cooling
during travel. The travel ensures least sugar crystal collision and minimum sugar
dust generation. The least sugar dust generation and prevention of crystal collision
ensures better sugar colour. The sugar dryer can handle different qualities of inlet
20 feed sugar.
In an embodiment of present disclose, a wave bed sugar dryer is provided. The wave
bed sugar dryer comprises an elongated hood having an inlet for wet sugar at a first
end and an outlet for dry sugar at a second end. The wave bed sugar dryer also
25 comprises a duct disposed onto the elongated hood. The duct comprises a hot air
duct portion and a cold air duct portion. The wave bed sugar dryer further comprises
a flexible bed extending between the inlet to the outlet of the elongated hood and
disposed inside the elongated hood. The flexible bed is connected to a frame of the
wave bed sugar dryer and comprises an upper surface adapted to support the sugar
30 during drying process and a lower surface opposite the upper surface. The wave bed
sugar dryer further comprises a plurality of paddle shafts disposed under the bed
and spaced along length of the bed. The plurality of paddle shafts is oriented below
4
the bed in such a way that in a pair of paddle shafts one paddle shaft is at an angle
with respect to an another paddle shaft, thereby impacting the lower surface of the
bed to generate an undulating bed movement to elevate and tumble the sugar on the
bed during travel from the inlet to the outlet for drying.
5
In the embodiment, the bed comprises two side edges, a front edge and a rear edge,
the said edges are clamped to the frame of the wave bed sugar dryer, to prevent
sugar leak.
10 In the embodiment, the bed is made any one of rubber material, canvas or cloth
material.
In the embodiment, the duct comprises a hot air duct portion and a cold air duct
portion.
15
In the embodiment, the duct comprises an air outlet duct disposed on a top wall of
the elongated hood.
In the embodiment, the duct comprises a plurality of flexible hanging pipes
20 extending from a bottom of the duct and up to the bed to discharge hot or cold air
onto the sugar during drying process.
In the embodiment, each paddle shaft comprises a trunnion shaft, two or more
cylinders rotatably connected to the trunnion shaft through flanges.
25
In the embodiment, the trunnion shaft of the paddle shaft is connected to a drive
mechanism, wherein the drive mechanism comprises a chain drive or a gear drive
or a combination of both.
30 In the embodiment, the two or more cylinders are at 180 degrees to each other and
are connected to the flanges.
In the embodiment, the trunnion shaft is connected at center of the flanges.
5
In the embodiment, the pair of paddle shafts having the one paddle shaft is at the
angle ranging from 20 degrees to 140 degrees, preferably 90 degrees with respect
to an another paddle shaft in the said pair of paddle shafts.
BRIEF DESCRIPTION OF THE ACCOMPANYING 5 DRAWINGS
The above and other features, aspects, and advantages of the subject matter will be
better understood with regard to the following description and accompanying
drawings:
10 FIG. 1: shows a perspective view of a wave bed sugar dryer according to an
exemplary embodiment of the present disclosure;
FIG. 2: shows a perspective view of a duct of the wave bed sugar dryer shown in
FIG. 1;
15
FIG. 3: shows a perspective view of a bed or a conveyor of the wave bed sugar
dryer shown in FIG. 1;
FIG. 4: shows a sectional view of the wave bed sugar dryer shown in FIG. 1 along
20 A-A’;
FIG. 5: shows a perspective view of a paddle shaft of the wave bed sugar dryer;
FIG. 6: shows a schematic diagram of wave motion of sugar in the wave bed sugar
25 dryer; and
FIG. 7: shows schematic diagram of clamping of flexible bed member with a frame
of the wave bed sugar dryer.
30 DETAILED DESCRIPTION OF THE DISCLOSURE WITH REFERENCE
TO ACCOMPANYING DRAWINGS
Provided below is a non-limiting exemplary embodiment of the present invention
and a reference will now be made in detail to specific embodiments or features,
examples of which are illustrated in the accompanying drawings. Wherever
6
possible, corresponding or similar reference numbers will be used throughout the
drawings to refer to the same or corresponding parts. Moreover, references to
various elements described herein, are made collectively or individually when there
may be more than one element of the same type. However, such references are
merely exemplary in nature. It may be noted that any reference 5 to elements in the
singular may also be construed to relate to the plural and vice-versa without limiting
the scope of the disclosure to the exact number or type of such elements unless set
forth explicitly in the appended claim(s).
10 FIG. 1 illustrates a perspective view of a wave bed sugar dryer (100) according to
an exemplary embodiment of the present disclosure. The wave bed sugar dryer
(100) as illustrated in the figure comprises an elongated hood (102). The terms
“wave bed sugar dryer” and “dryer” are interchangeably used in the present
disclosure. It is to be understood that both terms “wave bed sugar dryer” and “dryer”
15 relates to same device and it is used for brevity. Similarly, the terms “elongated
hood” and “hood” are interchangeably used in the present disclose. It is to be
understood that both the term “elongated hood” and “hood” are one and the same
and it is used for brevity. The elongated hood (102) in an exemplary embodiment
is generally a closed structure having a front wall (104), a rear wall (106), a frame
20 (108) at a bottom portion of the hood (102) and a pair of side walls (110) extending
from the frame (108) and connected to a top wall (112). In an exemplary
embodiment, the frame (108) may be, but not limited to, a vibratory frame. The
frame (108) may be supported by one or more supporting legs (114) which may in
turn rest on a ground surface (116) or a platform (not shown).
25
The elongated hood (102) of the dryer (100) comprises an inlet (118) for wet sugar
at a first end (120) of the dryer (100) and an outlet (122) for dry sugar at a second
end (124). In other words, the inlet (118) is provided at the front wall (104) of the
dryer (100) and the outlet (122) is provided at the rear wall (106) of the dryer (100).
30 In the illustrated embodiment, the hood (102) is provided with a duct (126) (more
clearly illustrated in FIG. 2) at the top wall (112) of the hood (102).
7
FIG. 2 illustrates a perspective view of the duct (126) of the wave bed sugar dryer
(100) shown in FIG. 1. The duct (126) is disposed onto the elongated hood (102),
particularly, the duct (126) is disposed at the top wall (112) of the hood (102) for
supplying hot and/or cold air inside the hood (102) during the process of sugar
drying. The duct (126) in the illustrated embodiment comprises 5 a hot air duct
portion (128) and a cold air duct portion (130). In the illustrated embodiment, the
hot air duct portion (128) is provided above the inlet (118) of the hood (102) and
extends to substantially to a half the portion of length of the elongated hood (102).
The hot air duct portion (128) comprises two hot air inlets (128A, 128B) at a top
10 surface (128C) of the hot air duct portion (128). The cold air duct portion (130) is
disposed subsequent to the hot air duct portion (128) and along the elongated hood
(102). However, the hot air duct portion (128) and the cold air duct portion (130)
are separated from each other. The cold air duct portion (130) comprises two cold
air inlets (130A, 130B) at side surfaces (130C) of the cold air duct portion (130).
15 The duct (126) further comprises an air outlet duct (132) disposed onto the top wall
(112) of the hood (102). In the illustrated embodiment, the air outlet duct (132) is
an elongated cylindrical duct (132A) having a length substantially equivalent to a
length of the hood (102) of the dryer (100). The air outlet duct (132) has an outlet
(132B) is provided to exit both the hot air and the cold air to outside surrounding of
20 the elongated hood (102) or the dryer (100).
The duct (126) further comprises a plurality of flexible hanging pipes (134)
extending from a bottom (136) of the duct (126) and up to a bed or a conveyor (132)
of the dryer (100) or the hopper. In the illustrated embodiment, both the hot air duct
25 portion (128) and the cold air duct portion (130) are provided with the flexible
hanging pipes (134). The flexible hanging pipes (134) are adapted to direct the hot
or the cold air onto the sugar present on the bed (138) during sugar drying process.
The supply of hot or cold air may be stopped in case the drying of sugar is not
required.
30
FIG. 3 illustrates a perspective view of the conveyor or the bed (138) of the dryer
(100) shown in FIG. 1. In the present disclosure, the terms “conveyor” and “bed”
8
is interchangeably used. It should be understood that both the terms “conveyor” and
“bed” are one and same. In an exemplary embodiment, the bed (138) is made from
a flexible material, such as, but not limited to, a rubber material, a canvas or a cloth
material. The flexible bed (138) is disposed inside the elongated hood (102) and is
adapted to extend from the front wall (104) to the rear wall (106) 5 of the hood (102).
That it to say, the flexible bed (138) is extended between the inlet (118) and the
outlet (122) of the elongated hood (102).
The flexible bed (138) is connected to the frame (108) of the elongated hood (102)
10 (shown in FIGS. 4 and 7). In other words, the bed (138) comprises a front edge
(138A), a rear edge (138B) and two side edges (138F), said edges (138A, 138B,
138F) being clamped to the frame (108) or a vibrating frame of the dryer (100), to
prevent sugar leak. In an exemplary embodiment, the flexible bed (138) may be
made of multiple segments (138C), wherein the multiple segments (138C) may be
15 stitched together or affixed together by a process known in the art to form the
elongated bed (138). The wet sugar is conveyed onto the flexible bed (138) from
the inlet (118) to the outlet (122) during processing/drying of the sugar. The flexible
bed (138) comprises an upper surface (138D) adapted to support the sugar during
drying process and a lower surface (138E) (shown in FIG. 6 and 7) opposite the
20 upper surface (138D). The lower surface (138E) of the bed (138) comes in contact
with a plurality of paddle shafts (140) (more clearly shown in FIGS. 4, 5 and 6)
provided below the frame (108) of the elongated hood (102). In an embodiment, the
bed (138) can form a height (H) from a horizontal surface of the frame (108). The
height (H) will be about 0.1 to 0.2 times width (Wb) of the bed (138) (shown in
25 FIG. 7).
FIG. 4 illustrates a sectional view of the wave bed sugar dryer (100) shown in FIG.
1 along A-A’. FIG. 5 illustrates a perspective view of the paddle shaft (140) of the
wave bed sugar dryer (100). The description of the paddle shaft (140) is based on
30 one paddle shaft. It is to be understood that the description of the remaining paddle
shafts will also be same since the construction of all the paddle shafts is same. The
plurality of paddle shafts (140) is disposed below the flexible bed (138),
9
particularly, the plurality of paddle shafts (140) is disposed under the bed (138) and
spaced along a length of the bed (138) (Shown in FIGS. 1, 3, and 6). Further, the
plurality of paddle shafts (140) is oriented below the bed (138) in such a way that
in a pair of paddle shafts one paddle shaft (140) is at an angle (a) with respect to an
another paddle shaft (140’), thereby impacting the lower surface 5 (138E) of the bed
(138) to generate an undulating bed movement (shown in FIG. 6) to elevate and
tumble the sugar (S) on the bed (138) during travel from the inlet (118) to the outlet
(122).
10 In the illustrated embodiment shown in FIG. 5, each paddle shaft (140) comprises
a trunnion shaft (142), two or more cylinders (144) rotatably connected to the
trunnion shaft (142) through flanges (146). In particular, the trunnion shaft (142) is
connected at a center (148) of the flange (146). In the preferred embodiment, the
two or more cylinders (144) are at 180 degrees to each other and are connected to
15 the flange (146). In another exemplary embodiment, the two or more cylinders
(144) may be at any angle apart from 180 degrees, for example, 120 degrees if there
are three cylinders, 90 degrees if there are four cylinders. The number of cylinders
(144) in the paddle shaft (140, 140’) is not meant to be limiting the scope of the
present invention. The numbers may be varied based on depth of crests or trough
20 caused during the undulating movement and / or tumbling movement to be caused
onto the bed (138). In the illustrated embodiment in figures of the present invention,
axes (not shown) of cylinders (144) are parallel to an axis (not shown) of the
trunnion shaft (142). The trunnion shaft (142) of the paddle shaft (140, 140’) is
connected to a drive mechanism (150) (shown in FIGS. 1 and 4). In an exemplary
25 embodiment, the drive mechanism (150) may comprise a chain drive or a gear drive
or a combination of both (not shown). In an embodiment, the trunnion shaft (142)
is fixedly connected to the flange (146) and is rotatably connected to the drive
mechanism (150). In an embodiment, the cylinders (144) being rotatably connected
to the flange (146) can be made through a pin joint (not shown), such that when the
30 trunnion shaft (142) is rotated by the drive mechanism (150), the flange (146) is
rotated thereby the cylinders (144) are also rotated along with the flange (146).
10
During this rotation the cylinders (144) coming in contact with the lower surface
(138E) of the bed (138) will also be rotated about the cylinder’s axes.
In an exemplary embodiment, the pair of paddle shafts (140, 140’) having the one
paddle shaft (140) is at an angle (a) of 90 degrees with respect to 5 an another paddle
shaft (140’) in the said pair of paddle shafts. However, in a pair of paddle shafts,
one paddle shaft (140) can be oriented at an angle (a) ranging from 20 degrees to
140 degrees. In another embodiment, one pair of paddle shafts (140, 140’) need not
be in same orientation as that of a subsequent pair of paddle shafts. That is to say,
10 the one pair of paddle shafts can be making an angle with another pair of paddle
shafts. However, the orientation of pair of paddle shafts should facilitate the wavy
movement of the bed (138) which fill expose the sugar present on the bed (138) for
better drying.
15 FIG. 6 illustrates a schematic diagram of wave motion of sugar in the wave bed
sugar dryer (100) in sequence “i” to “v”. The sequence “i” will start after
completion of the sequence “v”.
Wave motion of sugar crystal is generated along its travel on the bed (138). Wave
20 motion is achieved by the pair of paddle shafts (140, 140’), these shafts (140, 140’)
will always at 90° phase, powered by gear and motor mechanism. Wet sugar is
supplied to the dryer (100) on rubber/canvas bed (138) at the inlet (118). The pairs
of paddle shafts (140, 140’), which are at 90° phase to each other are placed below
the flexible bed (138). The paddle shafts (140, 140’) are assembled in such a way
25 that they make crest and trough in the flexible bed (138). The flexible bed (138) is
clamped from all four edges with the vibrating frame (108), thereby leaving no
room for sugar to leak downwards. The flexible bed (138) is clamped in such a way,
it forms downwards trough, in absence of the paddle shaft (140). The paddle shaft
(140) width (Wp) can be smaller than the width (Wb) of the flexible bed (138)
30 (approximately 0.12 to 0.75 times the flexible bed (138)). A low speed of about 5-
10 rpm can be given to these paddle shafts (138), with the mechanical drive
arrangement. A phase difference of 90° causes the sugar crystal to move like a
11
wave, when it travels forward. Due to this wave action, sugar gets transferred to the
outlet. During this process, the sugar crystals get random movement and mixing the
one at downside gets to top surface and vice versa. Referring to FIG. 6 where a
curve ABCD is shown toppling, exposing bottom layer of sugar to top and vice
versa. From the air ducts air (hot or cold) is discharged to the sugar 5 (this is used
when the equipment is used as dryer). During travel, wave action and hot / cold air
is supplied continuously.
Advantages
10 The present invention provides an innovative design for wave bed sugar hopper.
The invention is for the conveying motion of the sugar conveyor, which is generally
used for conveying sugar with or without sugar dryer feature. The present invention
explains the feature and comparison with dryer, however the patent claim stands
standalone sugar hopper or as a sugar dryer. In the present invention numbers of
15 paddle shaft used under the flexible are used to give wave motion to wet sugar on
the flexible sheet. The hopper can be used as sugar conveyor or as part of conveyor
for bed type sugar dryer.
In an embodiment, positive motion for different quality of inlet feed sugar is
20 achieved.
In an embodiment, since no vibrating motion is involved in the dryer, sugar sealing
is ensured and sugar spillage in ambient atmosphere is eliminated.
25 In an embodiment, due to low turbulence, minimum amount of dust generation is
observed.
In an embodiment, since there is low dust generation and less collision of sugar,
good desirable sugar crystal color is achieved.
30
In an embodiment, the dryer’s maintenance cost is low, as it runs at very low speed,
of about 5-10 rpm. Further, the dryer is highly reliable since the dryer includes slow
moving parts. In addition, there is less wear and care is required as compared to
12
vibrating equipments.
Industrial applicability
Present invention of particularly finds it application in sugar industry for drying the
sugar. However, the dryer may also find its application in drying 5 products such as,
but not limited to, agricultural products like, grains, nuts, fruits, silage etc., which
requires drying for better product yield and storage.
List of reference numerals and reference characters / signs
10 100: Wave bed sugar dryer
102: Elongated hood
104: Front wall
106: Rear wall
108: Frame
15 110: Side walls
112: Top wall
114: Supporting legs
116: Ground surface
118: Inlet
20 120: First end
122: Outlet
124: Second end
126: Duct
128: Hot air duct portion
25 128A: Hot air inlet
128B: Hot air inlet
128C: Top surface
130: Cold air duct portion
130A: Cold air inlet
13
130B: Cold air inlet
130C: Side surface
132: Air outlet duct
132A: Elongated cylindrical duct
132B: Outlet of the 5 air outlet duct
134: Hanging pipes
136: Bottom of the duct
138: Bed
138A: Front edge
10 138B: Rear edge
138C: Segments of bed
138D: Upper surface
138E: Lower surface
138F: Side edges
15 140: Paddle shaft
140’: Paddle shaft
142: Trunnion shaft
144: Cylinders
146: Flanges
20 148: Center
150: Drive mechanism
H: Height
Wp: Width of paddle shaft
Wb: Width of bed
25 S: Sugar
a: Angle

Claims:We Claim:
1. A wave bed sugar dryer (100), comprising:
an elongated hood (102), having an inlet (118) for wet sugar at a first end
(120) and an outlet (122) for dry sugar at a second end (124);
a duct (126) disposed onto the elongated hood (102), wherein 5 the duct (126)
comprises a hot air duct portion (128) and a cold air duct portion (130);
a flexible bed (138) extending between the inlet (118) to the outlet (122) of
the elongated hood (102) and disposed inside the elongated hood (102), the flexible
bed (138) being connected to a frame (108) of the wave bed sugar dryer (100) and
10 comprises an upper surface (138D) adapted to support the sugar during drying
process and a lower surface (138E) opposite the upper surface (138D);
a plurality of paddle shafts (140, 140’) disposed under the bed (138) and
spaced along length of the bed (138), wherein the plurality of paddle shafts (140,
140’) is oriented below the bed (138) in such a way that in a pair of paddle shafts
15 one paddle shaft (140) is at an angle (a) with respect to an another paddle shaft
(140’), thereby impacting the lower surface (138E) of the bed (138) to generate an
undulating bed movement to elevate and tumble the sugar on the bed (138) during
travel from the inlet (118) to the outlet (122) for drying.
20 2. The wave bed sugar dryer (100) as claimed in claim 1, wherein the bed (138)
comprises two side edges (138F), a front edge (138A) and a rear edge (138B), the
said edges (138A, 138B, 138F) being clamped to the frame (108) of the wave bed
sugar dryer (100), to prevent sugar leak.
25 3. The wave bed sugar dryer (100) as claimed in claim 1, wherein the bed (138) is
made any one of rubber material, canvas or cloth material.
4. The wave bed sugar dryer (100) as claimed in claim 1, wherein the duct (126)
comprises a hot air duct portion (128) and a cold air duct portion (130).
30
15
5. The wave bed sugar dryer (100) as claimed in claim 1, wherein duct (126)
comprises an air outlet duct (132) disposed on a top wall (112) of the elongated
hood (102).
6. The wave bed sugar dryer (100) as claimed in claim 1, wherein 5 the duct (126)
comprises a plurality of flexible hanging pipes (134) extending from a bottom (136)
of the duct (126) and up to the bed (138), to discharge hot or cold air onto the sugar
during drying process.
10 7. The wave bed sugar dryer (100) as claimed in claim 1, wherein each paddle shaft
(140, 140’) comprises a trunnion shaft (142), two or more cylinders (144) rotatably
connected to the trunnion shaft (142) through flanges (146).
8. The wave bed sugar dryer (100) as claimed in claim 7, wherein the trunnion shaft
15 (142) of the paddle shaft (140, 140’) is connected to a drive mechanism (150),
wherein the drive mechanism (150) comprises a chain drive or a gear drive or a
combination of both.
9. The wave bed sugar dryer (100) as claimed in claim 7, wherein the two or more
20 cylinders (144) are at 180 degrees to each other and are connected to the flanges
(146).
10. The wave bed sugar dryer (100) as claimed in claim 7, wherein the trunnion
shaft (142) is connected at center (148) of the flanges (146).
25
11. The wave bed sugar dryer (100) as claimed in claim 1, wherein the pair of paddle
shafts (140, 140’) having the one paddle shaft (140) is at the angle (a) ranging from
20 degrees to 140 degrees, preferably 90 degrees with respect to an another paddle
shaft (140’) in the said pair of paddle shafts (140, 140’).