CA2386243A1 - Process and apparatus for de-hulling and splitting lentils - Google Patents
Process and apparatus for de-hulling and splitting lentils Download PDFInfo
- Publication number
- CA2386243A1 CA2386243A1 CA002386243A CA2386243A CA2386243A1 CA 2386243 A1 CA2386243 A1 CA 2386243A1 CA 002386243 A CA002386243 A CA 002386243A CA 2386243 A CA2386243 A CA 2386243A CA 2386243 A1 CA2386243 A1 CA 2386243A1
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- Canada
- Prior art keywords
- rollers
- lentils
- kernels
- range
- gap
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- 235000014647 Lens culinaris subsp culinaris Nutrition 0.000 title claims abstract description 54
- 240000004322 Lens culinaris Species 0.000 title claims description 40
- 238000000034 method Methods 0.000 title claims description 21
- 239000002344 surface layer Substances 0.000 claims abstract description 23
- 241000219739 Lens Species 0.000 claims abstract description 14
- 239000000463 material Substances 0.000 claims description 11
- 239000010410 layer Substances 0.000 claims description 7
- 238000010008 shearing Methods 0.000 claims description 6
- 238000001035 drying Methods 0.000 claims description 3
- 238000010438 heat treatment Methods 0.000 claims description 3
- 239000000047 product Substances 0.000 description 6
- 230000003247 decreasing effect Effects 0.000 description 5
- 229920001971 elastomer Polymers 0.000 description 5
- 229910000831 Steel Inorganic materials 0.000 description 3
- 239000000806 elastomer Substances 0.000 description 3
- 239000012467 final product Substances 0.000 description 3
- 230000014759 maintenance of location Effects 0.000 description 3
- 229920000642 polymer Polymers 0.000 description 3
- 238000011084 recovery Methods 0.000 description 3
- 239000010959 steel Substances 0.000 description 3
- 230000000712 assembly Effects 0.000 description 2
- 238000000429 assembly Methods 0.000 description 2
- 235000013339 cereals Nutrition 0.000 description 2
- 239000007795 chemical reaction product Substances 0.000 description 2
- 238000013467 fragmentation Methods 0.000 description 2
- 238000006062 fragmentation reaction Methods 0.000 description 2
- 230000001788 irregular Effects 0.000 description 2
- 235000013372 meat Nutrition 0.000 description 2
- 239000004429 Calibre Substances 0.000 description 1
- 240000007594 Oryza sativa Species 0.000 description 1
- 235000007164 Oryza sativa Nutrition 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 238000010411 cooking Methods 0.000 description 1
- 238000006731 degradation reaction Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 235000013305 food Nutrition 0.000 description 1
- 239000012634 fragment Substances 0.000 description 1
- 239000010903 husk Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 229920002635 polyurethane Polymers 0.000 description 1
- 239000004814 polyurethane Substances 0.000 description 1
- 102000004169 proteins and genes Human genes 0.000 description 1
- 108090000623 proteins and genes Proteins 0.000 description 1
- 235000009566 rice Nutrition 0.000 description 1
- 238000012216 screening Methods 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B02—CRUSHING, PULVERISING, OR DISINTEGRATING; PREPARATORY TREATMENT OF GRAIN FOR MILLING
- B02B—PREPARING GRAIN FOR MILLING; REFINING GRANULAR FRUIT TO COMMERCIAL PRODUCTS BY WORKING THE SURFACE
- B02B3/00—Hulling; Husking; Decorticating; Polishing; Removing the awns; Degerming
- B02B3/04—Hulling; Husking; Decorticating; Polishing; Removing the awns; Degerming by means of rollers
- B02B3/045—Hulling; Husking; Decorticating; Polishing; Removing the awns; Degerming by means of rollers cooperating rollers
Landscapes
- Adjustment And Processing Of Grains (AREA)
Abstract
Lentils are fed in the form of a sheet of a single thickness of lentils to the gap (8) of a pair of opposed, cylindrical, slightly gapped, downwardly rotating rollers (9) ("chaffers"). Each chaffer has an elastic, resilient, circumferential surface layer (12) having a Shore A durometer hardness of 60-85. The rollers are gapped and rotated at a speed and speed differential operative to remove the hull when de-hulling and to split the kernels when splitting. De-hulling is conducted at ambient temperature and the resulting kernels are dried and heated for splitting.
Description
2 AND SPLITTING LENTILS
3
4 FIELD OF THE INVENTION
6 The present invention relates to a process and apparatus for de-hulling 7 and splitting lentils.
A lentil is a form of pea which comprises an internal kernel having an 11 external, thin, fibrous hull or husk. The kernel is generally shaped like a 12 football and has a plane of weakness along its midline so that it may be 13 separated down the middle into two halves. In the trade, the hulled kernels 14 are commonly referred to as "wholes" or "footballs" and the separated kernel halves are referred to as "splits".
16 Hulled splits provide a widely marketed food source. They are rich in 97 proteins and can be quickly cooked by boiling in water. It is desirable to split 18 the wholes to conserve energy used in cooking the lentils.
19 In Western Canada lentils are commonly de-hulled and split using a sequence of two machines referred to as a "huller" and a "splitter".
1 The huller comprises a stack of disc-shaped stones, slightly spaced 2 apart vertically and contained in a close-fitting drum or housing. The stones 3 are rotated within the drum by a common drive. The bottom outlet from the 4 drum is choked as required to control the retention time. The lentils are fed in at the top of the drum. As they slowly work their way down to the outlet, the 6 hulls are loosened and removed by frictional contact with the stones, drum 7 wall and other lentils.
8 The cleaned or hulled wholes are then fed into the splitter. This unit 9 comprises a pair of stacked, conically-shaped stones, slightly spaced apart vertically, contained in a close-fitting housing. The stones are rotated at 11 different speeds. In reaction to the regime of frictional forces to which they 12 are subjected as they pass through the splitter, the wholes are sub-divided 13 into splits.
14 This commercially applied equipment and procedure is characterized by certain shortcomings. More particularly:
16 ~ Too many of the lentils may be insufficiently de-hulled. This is 17 particularly a problem with large lentils having flat or irregular 18 surfaces. As a result, the end product of hulled splits may be 19 contaminated with too high a proportion of hull material;
~ Too many of the hulled kernels may become chipped, with the 21 result that part of the kernel is lost as fragments with the chaff; and 22 ~ Too many of the splits may be chipped with consequent losses of 23 valuable kernel material.
22-11-2001 . ~ CA000120:
1 Typically, these prior art commercial operations will have losses of kernel 2 material in the order of 20 -' 30% and contamination of the end product with 3 hull material will often exceed the international standard of 1.5% maximum 4 . hull content.
' The present invention has as objectives:
6 ' ~ reducing fragmentation or chipping of the wholes and splits;
7 ~ improving the efficiency of removing hulls to thereby reduce the 8 proportion of hull material in the final product; .
9 ' ~ increasing the production of splits as the final product; and ~ providing a system which is able to successfully process a variety of 11 lentil types, particularly large lentils having irregular surfaces.
12 The published prior art is represented most relevantly by EPO patent 13 application 820814 A1 ~Satake et ai). This reference teaches that it is know to 14 use gapped, contra-rotating rubber rolls, operated at different rotation speeds, to de-hull feed such as rice.
17 ' SUMMARY OF THE INVENTION
18 In accordance with the invention, I have combined apparatus and 19 process steps and conditions to achieve improved recovery and purity of hulled splits. More particularly, the invention involves:
21 ~ Providing a pair of opposed, cylindrical, slightly gapped, 22 downwardly rotating rollers referred to as 'chaffers'. Each chaffer 23 has a rubber-like or elastic, resilient, circumferential surface layer.
24 The rubber like layer is preferably formed of polymer or elastomer (EMt 95031.DOC:1)3 AMENDED SHEET
22-11-2001 CA000120.
1 and preferably has a Shore A durometer hardness of about 60 - 85, 2 more preferably about 65 - 85. This range has been found to 3 provide good adherence to the hull. If the hardness is less than 4 about Shore A 60, the feed submerges too deeply in the chaffer surface layer and de-hulling suffers. If the hardness is greater than 6 about Shore A 85, increased chipping of the lentils results. The 7 chaffer surfaces are spaced apart, preferably to form a gap just less .
8 than one split in width. Preferably the gap spacing is about 20 -9 30/1000 of an inch, optimally about 2411000" for large calibre lentil.
The gap spacing provides minimal. chipping during splitting. The 11 ~ chaffers are rotated at different speeds to provide a frictional 12 shearing effect adequate to remove the hull when de-hulling and to 13 split the kernels when splitting. In addition the chaffers are rotated 14 at speeds selected to provide adequate retention time to achieve the desired quality of de-hulling and splitting. Preferably the 16 chaffers are operated at a rotational speed differential in the range 17 of about 56 - 61 %, more preferably 58 - 61 %. If the differential is 18 lower than about 56%, shearing is less adequate for de-hulling and 19 splitting. If it is higher than. 61 %, retention time is short and de-hulling and splitting results suffer. In addition, the feed exit velocity 21 . from the chaffers becomes excessive and further chipping occurs.
22 Optimally, I operate a pair of 15" diameter chaffers at 675 - 685 23 rpm for one chaffer and 1060 - 1090 rpm, for the other, respectively;
{EM195031.DOC;1~
AMENDED SHEET
1 ~ Preferably providing a feed means for supplying the lentils or 2 kernels to the top end of the chaffer gap in the form of a laterally 3 extending sheet of single lentils or kernels (that is, the sheet is only 4 one lentil or kernel in thickness) - if the feed is stacked in layers during feeding, chipping is increased;
6 ~ Preferably providing~an exit chute, at the bottom of the chaffer gap, 7. which is adapted to direct the- product into a container with- a 8 minimum of chipping. More particularly the chute may be a flat, 9 curved tube that has top and bottom walls that are closely spaced to contain and guide the emitted product while minimizing zig-zag 11 movements that can lead to chipping. The kernels leave the 12 differentially rotating chaffers at high velocity and at an angle. It is 13 therefore desirable to channel and guide them to the container with 14 a chute designed to minimize fragmentation; and ~ Preferably passing the lentils and whole kernels in sequence 16 through chaffers in a two stage process of de-hulling and splitting at 17 controlled temperatures. Preferably the same pair of chaffers are 18 used for each of the two stages. 1n the first stage, the lentils, at 19 ambient temperature, preferably at a temperature of about -10°C to +27°C, most preferably -10 to 20°C, are passed through the 21 chaffers to remove about 80 - 90% of the hull material and produce 22 about 97% cleaned wholes and about 3% splits. If the temperature 23 of the feed in the first stage is less than about minus 10°C, hull 24 separation deteriorates. If the temperature is greater than about (EM195031.DOC;1}~J
AMENDED SHEET
22-11-2001 . CA000120:
1 27°C, de-hulling suffers and a greater quantity of splits is produced.
2 The product is then dried and heated, for example in a grain dryer, 3 preferably to about 30 - 41 °C to weaken the adhesiveness of the 4 splits forming the wholes. If the temperature of the wholes fed to splitting is less than about 30°C, there is a decrease in the yield of 6 splits. If the temperature of the wholes is greater than about 41°C, 7 . the meat of the kernels is degraded. The heated wholes are then 8 passed through the chaffers for splitting.
9 As a result of processing the lentils in this way, one can recover 85 - 88%
of the original kernel material or meat in the form of splits with a hull content less 11 than 1.5%. The purity of the splits product is in the order of 99%. The losses 12 of kernel ir~aterial has been reduced to about 12 -14%, compared to the prior 13 art system losses of about 20 -30%.
14 In one aspect, the invention is directed to a process comprising:
~ de-hulling lentils at a temperature of about -10°C to 27°C by 16 ~ feeding them through the gap of a pair of spaced apart, opposed, _ 17 . downwardly rotating chaffers having elastomeric surface layers and 1'8 being rotated at different speeds so that they are operative to apply 19 . adequate frictional shearing to de-hull substantially all of the lentils to produce substantially clean "wholes" or kernels;
21 ~ drying and heating the cleaned wholes to a temperature of about 22 30 °C to 41°C; and 23 ~ splitting the dried heated wholes by feeding them through the gap of 24 a pair of spaced apart, opposed, downwardly rotating chaffers (EM19503f .DOG; f }6 _ AMENDED SHEEN' 22-11-2001 CA000120:
CA 02386243 2002-04-03~
1 having elastomeric surface layers and being rotated at different 2 speeds so that they are operative to apply adequate frictional 3 shearing so as to split substantially all of the wholes to produce 4 substantially clean splits.
In another aspect, the invention is directed to an assembly comprising:
6 ~ a pair of cylindrical, driven, gapped, downwardly rotating rollers l 7 having elastomer or polymer surface layers having a Shore A
l 8 durometer hardness of about 60 - 85, the rollers being rotated at 9 different speeds so that the differential is about 58 - fit °~, the rollers being spaced apart about 20 - 30/1000";
11 . flat means for feeding lentils or lentil wholes to the gap between the 12 rollers as a single unit layer - that is, the layer is formed of lentils 13 ~ (or wholes) that are not stacked one on another; and ' 14 ~ curved flat tube means for receiving hulled lentil wholes or splits ' issuing from the gap and closely containing them white delivering 16 them to storage container means.
17 Broadly stated the invention in one form comprises a method for de-18 hulling lentils, each comprising a kernel covered by a hull, the kernel 19 consisting of a pair of united halves or splits, to produce whole kernels comprising: passing lentils, at ambient temperature through a pair of 21 opposed, cylindrical, gapped, downwardly rotating, driven rollers, the rollers 22 being gapped to provide a gap spacing in the range 20/1000 to 3011000 of an 23 ~ inch, each having an elastic, resilient circumferential surface layer formed of 24 material having a Shore A durometer hardness in the range 60 to 85, the {EM195031.DOC:1}7 AMENDED SHEET
22-11-2001 ~ CA000120;
1 rollers being rotated at different speeds selected to provide sufficient frictional 2 shearing so that the major portion of the lentil hulls is removed to produce 3 hulled whole kernels.
4 Broadly stated, the invention in another form comprises a method for de-hulling lentils, each comprising a kernel covered by a hull, the kernel 6 consisting of a pair of united halves or 'splits', and splitting the hulled kernel 7 into splits, comprising: passing lentils at ambient temperature through a pair 8 of opposed, cylindrical, gapped, downwardly rotating, driven rollers, each 9 having an elastic, resilient circumferentiai surface layer, the rollers being rotated at different speeds, the Shore A durometer hardness of the roller 11 surface layers, the gap befinreen the rollers, the roller speeds and their 12 differential in speed being collectively operative so as to substantially remove 13 the lentil hulls and produce hulled kernels; heating and drying the kernels to at 14 least 30°C to produce kernels amenable to splitting; and passing the produced kernels through a pair of opposed, cylindrical, gapped, downwardly rotating, 18 driven rollers, each having an elastic, resilient circumferential surface layer,.
17 the rollers being rotated at different speeds; the Shore A durometer hardness 18 of the roller surface layers, the gap between the rollers, the roller speeds and 19 their differential in speed being collectively operative so as to split the kernel into splits.
21 And in another form the invention comprises apparatus for de-hulling 22 lentils, each comprising ~a Kernel covered by a hull, to produce whole kernels, 23 comprising a pair of opposed, cylindrical, gapped, downwardly rotatable ' 24 rollers; each roller having an elastic, resilient circurnferential surface layer {EM195031.DOC:1}$
AMENDED SHEET
22-11-2001 CA000120:
1 formed of material havin a Shore A durometer hardness in the ran a of 60 -. 2 85; the rollers having a gap spacing in the range 2011000 to 30/1000 of an 3 inch; and means for individually rotating each roller so that the rollers may be 4 operated at a rotational speed differential.
DESCRIPTION OF THE DRAWINGS
6 Figure 1 is a schematic side view showing the feed hopper and tray, 7 chaffers, exit tube and product container;
8 Figure 2 is an expanded view of part of Figure 1;
9 Figure 3 is a top plan view of the chaffers and their drive assemblies;
and 11 Figure 4 is a perspective view of the assembly.
13 The invention will now be described in connection with a test run at 14 optimum conditions.
In accordance with the Figures, a feed hopper 1 was- provided for 16 feeding lentils (in a first stage) and hulled wholes (in a second stage) onto a 17 wide, downwardly angled tray 2. The tray 2 comprised a bottom wall 3 and 18 side walls 4. A plurality of upstanding dividers 5 sub-divided the upper end of 19 the tray 2 into parallel channels 6 extending part of the length of the tray. The upper end of the tray 2 was open but its lower end was closed in by a top wall 21 7 to form a flat tube. The tray 2 extended between the hopper 1 and the gap 22 8 formed between the chaffers 9. The widths of the hopper 1 and tray 2 were 23 substantially equal to the length of the gap 8. The hopper fed the lentils to the 24 tray as a train or sheet of feed, one feed unit.thick, moving down the channels {EM195031.DOC;1}9 _ AMENDED SHEET
1 6. Otherwise stated, a feed means, comprising the hopper 1 and tray 2, was 2 provided for feeding feed in the form of a sheet, substantially one feed unit 3 thick, to the chaffer gap 8 along its length.
4 The chaffers 9 were a pair of cylindrical hollow steel drums 11, each coated with an elastomeric surface layer 12. The steel drums 11 had an O. D.
6 of 15" and length of 24". Each was coated with a layer 12 of polyurethane, 7 about 0.5 inches thick. The polymer was obtained from Rubberworld 8 Industries Inc. of Edmonton, Alberta, Canada. The elastomer was bonded to 9 the steel. It had a Shore A hardness of about 65. The chaffers 9 were evenly spaced apart .024" to form the gap 8. The chaffers 9 were horizontally and 11 rotatably mounted in a frame 14. Conventional belt and sprocket assemblies 12 15, driven by hydraulic motors 16, separately rotated each of the chaffers 9 at 13 a variable selected speed. The chaffers were operated at 675-685 and 1060 -14 1090 rpm respectively to provide a speed differential of about 59.5°r6.
An exit chute 20 extended along and downwardly from the gap 8 to the 16 storage container 21 or other delivery point. The exit chute 20 was a flat tube 17 extending the length of the gap 8. It comprised top, bottom and side walls 22, 18 23 and 24. The top and bottom walls 22, 23 were spaced apart 518 inches.
19 The chute 20 was curved and had a length of about 14".
In the first stage or pass of the process, de-hulling, the lentils, at a 21 temperature of 19 - 22°C, were supplied to the gap 8 as a feed layer with the 22 lentils close together but only one unit thick. After passing through the 23 chaffers 9, the chaff and kernel chips were separated by screening. The 24 product, hulled wholes, was then heated in a grain dryer (not shown) to raise SUBSTITUTE SHEET (RULE 28) 1 the feed temperature to 38 - 40°C. The heated feed was then fed through the 2 same chaffers 9 in the same way as the original lentils. Following are the 3 results of the run:
4 De-hulling:
~ yield of hulled whole kernels - 75.1 6 ~ yield of unhulled whole kernels -17.9%
7 ~ yield of hulled splits - 0.68%
8 ~ yield of unhulled splits - 0.05%
9 ~ losses (hulls and chips) - 6.22%
Splitting:
11 ~ yield of hulled wholes - 17.1 12 ~ yield of unhulled wholes - 4.3°~
13 ~ yield of hulled splits - 72°~6 14 ~ yield of unhulled splits - 0.9%
~ losses (hulls and chips) - 5.7°~.
16 A number of runs using the assembly shown have been carried out at 17 varying conditions. The following observations have been made, comparing 18 them to the optimum run described:
19 ~ In de-hulling, with increasing temperature of the feed, the recovery of hulled wholes decreased and the recovery and purity of splits 21 decreased;
22 ~ When the speed differential was 55% the percentage of hulled 23 wholes was less and when the speed differential was 65°r6 the 24 percentage of hulled wholes decreased;
SUBSTITUTE SHEET (RULE 26) ~ If the gap was 0.022", hull and chip losses increased, if the gap was 2 0.030", purity of the final product decreased;
3 ~ If the splitting temperature was 30°C, split yield decreased and if the 4 temperature was greater than 41 °C, kernel degradation was noted.
SUBSTITUTE SHEET (RULE 26)
6 The present invention relates to a process and apparatus for de-hulling 7 and splitting lentils.
A lentil is a form of pea which comprises an internal kernel having an 11 external, thin, fibrous hull or husk. The kernel is generally shaped like a 12 football and has a plane of weakness along its midline so that it may be 13 separated down the middle into two halves. In the trade, the hulled kernels 14 are commonly referred to as "wholes" or "footballs" and the separated kernel halves are referred to as "splits".
16 Hulled splits provide a widely marketed food source. They are rich in 97 proteins and can be quickly cooked by boiling in water. It is desirable to split 18 the wholes to conserve energy used in cooking the lentils.
19 In Western Canada lentils are commonly de-hulled and split using a sequence of two machines referred to as a "huller" and a "splitter".
1 The huller comprises a stack of disc-shaped stones, slightly spaced 2 apart vertically and contained in a close-fitting drum or housing. The stones 3 are rotated within the drum by a common drive. The bottom outlet from the 4 drum is choked as required to control the retention time. The lentils are fed in at the top of the drum. As they slowly work their way down to the outlet, the 6 hulls are loosened and removed by frictional contact with the stones, drum 7 wall and other lentils.
8 The cleaned or hulled wholes are then fed into the splitter. This unit 9 comprises a pair of stacked, conically-shaped stones, slightly spaced apart vertically, contained in a close-fitting housing. The stones are rotated at 11 different speeds. In reaction to the regime of frictional forces to which they 12 are subjected as they pass through the splitter, the wholes are sub-divided 13 into splits.
14 This commercially applied equipment and procedure is characterized by certain shortcomings. More particularly:
16 ~ Too many of the lentils may be insufficiently de-hulled. This is 17 particularly a problem with large lentils having flat or irregular 18 surfaces. As a result, the end product of hulled splits may be 19 contaminated with too high a proportion of hull material;
~ Too many of the hulled kernels may become chipped, with the 21 result that part of the kernel is lost as fragments with the chaff; and 22 ~ Too many of the splits may be chipped with consequent losses of 23 valuable kernel material.
22-11-2001 . ~ CA000120:
1 Typically, these prior art commercial operations will have losses of kernel 2 material in the order of 20 -' 30% and contamination of the end product with 3 hull material will often exceed the international standard of 1.5% maximum 4 . hull content.
' The present invention has as objectives:
6 ' ~ reducing fragmentation or chipping of the wholes and splits;
7 ~ improving the efficiency of removing hulls to thereby reduce the 8 proportion of hull material in the final product; .
9 ' ~ increasing the production of splits as the final product; and ~ providing a system which is able to successfully process a variety of 11 lentil types, particularly large lentils having irregular surfaces.
12 The published prior art is represented most relevantly by EPO patent 13 application 820814 A1 ~Satake et ai). This reference teaches that it is know to 14 use gapped, contra-rotating rubber rolls, operated at different rotation speeds, to de-hull feed such as rice.
17 ' SUMMARY OF THE INVENTION
18 In accordance with the invention, I have combined apparatus and 19 process steps and conditions to achieve improved recovery and purity of hulled splits. More particularly, the invention involves:
21 ~ Providing a pair of opposed, cylindrical, slightly gapped, 22 downwardly rotating rollers referred to as 'chaffers'. Each chaffer 23 has a rubber-like or elastic, resilient, circumferential surface layer.
24 The rubber like layer is preferably formed of polymer or elastomer (EMt 95031.DOC:1)3 AMENDED SHEET
22-11-2001 CA000120.
1 and preferably has a Shore A durometer hardness of about 60 - 85, 2 more preferably about 65 - 85. This range has been found to 3 provide good adherence to the hull. If the hardness is less than 4 about Shore A 60, the feed submerges too deeply in the chaffer surface layer and de-hulling suffers. If the hardness is greater than 6 about Shore A 85, increased chipping of the lentils results. The 7 chaffer surfaces are spaced apart, preferably to form a gap just less .
8 than one split in width. Preferably the gap spacing is about 20 -9 30/1000 of an inch, optimally about 2411000" for large calibre lentil.
The gap spacing provides minimal. chipping during splitting. The 11 ~ chaffers are rotated at different speeds to provide a frictional 12 shearing effect adequate to remove the hull when de-hulling and to 13 split the kernels when splitting. In addition the chaffers are rotated 14 at speeds selected to provide adequate retention time to achieve the desired quality of de-hulling and splitting. Preferably the 16 chaffers are operated at a rotational speed differential in the range 17 of about 56 - 61 %, more preferably 58 - 61 %. If the differential is 18 lower than about 56%, shearing is less adequate for de-hulling and 19 splitting. If it is higher than. 61 %, retention time is short and de-hulling and splitting results suffer. In addition, the feed exit velocity 21 . from the chaffers becomes excessive and further chipping occurs.
22 Optimally, I operate a pair of 15" diameter chaffers at 675 - 685 23 rpm for one chaffer and 1060 - 1090 rpm, for the other, respectively;
{EM195031.DOC;1~
AMENDED SHEET
1 ~ Preferably providing a feed means for supplying the lentils or 2 kernels to the top end of the chaffer gap in the form of a laterally 3 extending sheet of single lentils or kernels (that is, the sheet is only 4 one lentil or kernel in thickness) - if the feed is stacked in layers during feeding, chipping is increased;
6 ~ Preferably providing~an exit chute, at the bottom of the chaffer gap, 7. which is adapted to direct the- product into a container with- a 8 minimum of chipping. More particularly the chute may be a flat, 9 curved tube that has top and bottom walls that are closely spaced to contain and guide the emitted product while minimizing zig-zag 11 movements that can lead to chipping. The kernels leave the 12 differentially rotating chaffers at high velocity and at an angle. It is 13 therefore desirable to channel and guide them to the container with 14 a chute designed to minimize fragmentation; and ~ Preferably passing the lentils and whole kernels in sequence 16 through chaffers in a two stage process of de-hulling and splitting at 17 controlled temperatures. Preferably the same pair of chaffers are 18 used for each of the two stages. 1n the first stage, the lentils, at 19 ambient temperature, preferably at a temperature of about -10°C to +27°C, most preferably -10 to 20°C, are passed through the 21 chaffers to remove about 80 - 90% of the hull material and produce 22 about 97% cleaned wholes and about 3% splits. If the temperature 23 of the feed in the first stage is less than about minus 10°C, hull 24 separation deteriorates. If the temperature is greater than about (EM195031.DOC;1}~J
AMENDED SHEET
22-11-2001 . CA000120:
1 27°C, de-hulling suffers and a greater quantity of splits is produced.
2 The product is then dried and heated, for example in a grain dryer, 3 preferably to about 30 - 41 °C to weaken the adhesiveness of the 4 splits forming the wholes. If the temperature of the wholes fed to splitting is less than about 30°C, there is a decrease in the yield of 6 splits. If the temperature of the wholes is greater than about 41°C, 7 . the meat of the kernels is degraded. The heated wholes are then 8 passed through the chaffers for splitting.
9 As a result of processing the lentils in this way, one can recover 85 - 88%
of the original kernel material or meat in the form of splits with a hull content less 11 than 1.5%. The purity of the splits product is in the order of 99%. The losses 12 of kernel ir~aterial has been reduced to about 12 -14%, compared to the prior 13 art system losses of about 20 -30%.
14 In one aspect, the invention is directed to a process comprising:
~ de-hulling lentils at a temperature of about -10°C to 27°C by 16 ~ feeding them through the gap of a pair of spaced apart, opposed, _ 17 . downwardly rotating chaffers having elastomeric surface layers and 1'8 being rotated at different speeds so that they are operative to apply 19 . adequate frictional shearing to de-hull substantially all of the lentils to produce substantially clean "wholes" or kernels;
21 ~ drying and heating the cleaned wholes to a temperature of about 22 30 °C to 41°C; and 23 ~ splitting the dried heated wholes by feeding them through the gap of 24 a pair of spaced apart, opposed, downwardly rotating chaffers (EM19503f .DOG; f }6 _ AMENDED SHEEN' 22-11-2001 CA000120:
CA 02386243 2002-04-03~
1 having elastomeric surface layers and being rotated at different 2 speeds so that they are operative to apply adequate frictional 3 shearing so as to split substantially all of the wholes to produce 4 substantially clean splits.
In another aspect, the invention is directed to an assembly comprising:
6 ~ a pair of cylindrical, driven, gapped, downwardly rotating rollers l 7 having elastomer or polymer surface layers having a Shore A
l 8 durometer hardness of about 60 - 85, the rollers being rotated at 9 different speeds so that the differential is about 58 - fit °~, the rollers being spaced apart about 20 - 30/1000";
11 . flat means for feeding lentils or lentil wholes to the gap between the 12 rollers as a single unit layer - that is, the layer is formed of lentils 13 ~ (or wholes) that are not stacked one on another; and ' 14 ~ curved flat tube means for receiving hulled lentil wholes or splits ' issuing from the gap and closely containing them white delivering 16 them to storage container means.
17 Broadly stated the invention in one form comprises a method for de-18 hulling lentils, each comprising a kernel covered by a hull, the kernel 19 consisting of a pair of united halves or splits, to produce whole kernels comprising: passing lentils, at ambient temperature through a pair of 21 opposed, cylindrical, gapped, downwardly rotating, driven rollers, the rollers 22 being gapped to provide a gap spacing in the range 20/1000 to 3011000 of an 23 ~ inch, each having an elastic, resilient circumferential surface layer formed of 24 material having a Shore A durometer hardness in the range 60 to 85, the {EM195031.DOC:1}7 AMENDED SHEET
22-11-2001 ~ CA000120;
1 rollers being rotated at different speeds selected to provide sufficient frictional 2 shearing so that the major portion of the lentil hulls is removed to produce 3 hulled whole kernels.
4 Broadly stated, the invention in another form comprises a method for de-hulling lentils, each comprising a kernel covered by a hull, the kernel 6 consisting of a pair of united halves or 'splits', and splitting the hulled kernel 7 into splits, comprising: passing lentils at ambient temperature through a pair 8 of opposed, cylindrical, gapped, downwardly rotating, driven rollers, each 9 having an elastic, resilient circumferentiai surface layer, the rollers being rotated at different speeds, the Shore A durometer hardness of the roller 11 surface layers, the gap befinreen the rollers, the roller speeds and their 12 differential in speed being collectively operative so as to substantially remove 13 the lentil hulls and produce hulled kernels; heating and drying the kernels to at 14 least 30°C to produce kernels amenable to splitting; and passing the produced kernels through a pair of opposed, cylindrical, gapped, downwardly rotating, 18 driven rollers, each having an elastic, resilient circumferential surface layer,.
17 the rollers being rotated at different speeds; the Shore A durometer hardness 18 of the roller surface layers, the gap between the rollers, the roller speeds and 19 their differential in speed being collectively operative so as to split the kernel into splits.
21 And in another form the invention comprises apparatus for de-hulling 22 lentils, each comprising ~a Kernel covered by a hull, to produce whole kernels, 23 comprising a pair of opposed, cylindrical, gapped, downwardly rotatable ' 24 rollers; each roller having an elastic, resilient circurnferential surface layer {EM195031.DOC:1}$
AMENDED SHEET
22-11-2001 CA000120:
1 formed of material havin a Shore A durometer hardness in the ran a of 60 -. 2 85; the rollers having a gap spacing in the range 2011000 to 30/1000 of an 3 inch; and means for individually rotating each roller so that the rollers may be 4 operated at a rotational speed differential.
DESCRIPTION OF THE DRAWINGS
6 Figure 1 is a schematic side view showing the feed hopper and tray, 7 chaffers, exit tube and product container;
8 Figure 2 is an expanded view of part of Figure 1;
9 Figure 3 is a top plan view of the chaffers and their drive assemblies;
and 11 Figure 4 is a perspective view of the assembly.
13 The invention will now be described in connection with a test run at 14 optimum conditions.
In accordance with the Figures, a feed hopper 1 was- provided for 16 feeding lentils (in a first stage) and hulled wholes (in a second stage) onto a 17 wide, downwardly angled tray 2. The tray 2 comprised a bottom wall 3 and 18 side walls 4. A plurality of upstanding dividers 5 sub-divided the upper end of 19 the tray 2 into parallel channels 6 extending part of the length of the tray. The upper end of the tray 2 was open but its lower end was closed in by a top wall 21 7 to form a flat tube. The tray 2 extended between the hopper 1 and the gap 22 8 formed between the chaffers 9. The widths of the hopper 1 and tray 2 were 23 substantially equal to the length of the gap 8. The hopper fed the lentils to the 24 tray as a train or sheet of feed, one feed unit.thick, moving down the channels {EM195031.DOC;1}9 _ AMENDED SHEET
1 6. Otherwise stated, a feed means, comprising the hopper 1 and tray 2, was 2 provided for feeding feed in the form of a sheet, substantially one feed unit 3 thick, to the chaffer gap 8 along its length.
4 The chaffers 9 were a pair of cylindrical hollow steel drums 11, each coated with an elastomeric surface layer 12. The steel drums 11 had an O. D.
6 of 15" and length of 24". Each was coated with a layer 12 of polyurethane, 7 about 0.5 inches thick. The polymer was obtained from Rubberworld 8 Industries Inc. of Edmonton, Alberta, Canada. The elastomer was bonded to 9 the steel. It had a Shore A hardness of about 65. The chaffers 9 were evenly spaced apart .024" to form the gap 8. The chaffers 9 were horizontally and 11 rotatably mounted in a frame 14. Conventional belt and sprocket assemblies 12 15, driven by hydraulic motors 16, separately rotated each of the chaffers 9 at 13 a variable selected speed. The chaffers were operated at 675-685 and 1060 -14 1090 rpm respectively to provide a speed differential of about 59.5°r6.
An exit chute 20 extended along and downwardly from the gap 8 to the 16 storage container 21 or other delivery point. The exit chute 20 was a flat tube 17 extending the length of the gap 8. It comprised top, bottom and side walls 22, 18 23 and 24. The top and bottom walls 22, 23 were spaced apart 518 inches.
19 The chute 20 was curved and had a length of about 14".
In the first stage or pass of the process, de-hulling, the lentils, at a 21 temperature of 19 - 22°C, were supplied to the gap 8 as a feed layer with the 22 lentils close together but only one unit thick. After passing through the 23 chaffers 9, the chaff and kernel chips were separated by screening. The 24 product, hulled wholes, was then heated in a grain dryer (not shown) to raise SUBSTITUTE SHEET (RULE 28) 1 the feed temperature to 38 - 40°C. The heated feed was then fed through the 2 same chaffers 9 in the same way as the original lentils. Following are the 3 results of the run:
4 De-hulling:
~ yield of hulled whole kernels - 75.1 6 ~ yield of unhulled whole kernels -17.9%
7 ~ yield of hulled splits - 0.68%
8 ~ yield of unhulled splits - 0.05%
9 ~ losses (hulls and chips) - 6.22%
Splitting:
11 ~ yield of hulled wholes - 17.1 12 ~ yield of unhulled wholes - 4.3°~
13 ~ yield of hulled splits - 72°~6 14 ~ yield of unhulled splits - 0.9%
~ losses (hulls and chips) - 5.7°~.
16 A number of runs using the assembly shown have been carried out at 17 varying conditions. The following observations have been made, comparing 18 them to the optimum run described:
19 ~ In de-hulling, with increasing temperature of the feed, the recovery of hulled wholes decreased and the recovery and purity of splits 21 decreased;
22 ~ When the speed differential was 55% the percentage of hulled 23 wholes was less and when the speed differential was 65°r6 the 24 percentage of hulled wholes decreased;
SUBSTITUTE SHEET (RULE 26) ~ If the gap was 0.022", hull and chip losses increased, if the gap was 2 0.030", purity of the final product decreased;
3 ~ If the splitting temperature was 30°C, split yield decreased and if the 4 temperature was greater than 41 °C, kernel degradation was noted.
SUBSTITUTE SHEET (RULE 26)
Claims (14)
EXCLUSIVE PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS
FOLLOWS:
1. A method for de-hulling lentils, each comprising a kernel covered by a hull, the kernel consisting of a pair of united halves or splits, to produce whole kernels comprising:
passing- lentils, at ambient temperature, through a pair of opposed, cylindrical, gapped, downwardly rotating, driven rollers, the rollers being gapped to provide a gap spacing in the range 20/1000 to 30/1000 of an inch, each having an elastic, resilient circumferential surface layer formed of material having a Shore A durometer hardness in the range 60 to 85, the rollers being rotated at different speeds selected to provide sufficient frictional shearing so that the major portion of the lentil hulls is removed to produce hulled whole kernels.
passing- lentils, at ambient temperature, through a pair of opposed, cylindrical, gapped, downwardly rotating, driven rollers, the rollers being gapped to provide a gap spacing in the range 20/1000 to 30/1000 of an inch, each having an elastic, resilient circumferential surface layer formed of material having a Shore A durometer hardness in the range 60 to 85, the rollers being rotated at different speeds selected to provide sufficient frictional shearing so that the major portion of the lentil hulls is removed to produce hulled whole kernels.
2. The method as set forth in claim 1 wherein:
the rollers are operated at a rotational speed differential in the range 56 to 61 %.
the rollers are operated at a rotational speed differential in the range 56 to 61 %.
3. The method as set forth in claim 2 wherein:
the lentils are at a temperature in the range minus 10°C to 27°C.
the lentils are at a temperature in the range minus 10°C to 27°C.
4. The method as set forth in claim 3 comprising:
passing the produced kernels through a pair of opposed, cylindrical, gapped, downwardly rotating, driven rollers, each having an elastic, resilient circumferential surface layer, the rollers being rotated at different speeds, the Shore A durometer hardness of the roller surface layers, the gap between the rollers, the roller speeds and their differential in speed being collectively operative so as to split the kernels into splits.
passing the produced kernels through a pair of opposed, cylindrical, gapped, downwardly rotating, driven rollers, each having an elastic, resilient circumferential surface layer, the rollers being rotated at different speeds, the Shore A durometer hardness of the roller surface layers, the gap between the rollers, the roller speeds and their differential in speed being collectively operative so as to split the kernels into splits.
5. The method as set forth in claim 4 wherein:
the rollers doing the splitting have a Shore A durometer hardness in the range 60 to 85;
the rollers are gapped to provide a gap spacing in the range 20/1000 to 30/1000 of an inch; and the rollers are operated at a rotational speed differential in the range 56 to 61 %.
the rollers doing the splitting have a Shore A durometer hardness in the range 60 to 85;
the rollers are gapped to provide a gap spacing in the range 20/1000 to 30/1000 of an inch; and the rollers are operated at a rotational speed differential in the range 56 to 61 %.
6. The method as set forth in claim 5 wherein:
the roller surface layer Shore A durometer hardness is in the range 65 to 85.
the roller surface layer Shore A durometer hardness is in the range 65 to 85.
7. The method as set forth in claim 5 wherein:
the lentils are at a temperature in the range 10°C to 20°C; and the roller surface layer Shore A durometer hardness is in the range 65 to 85.
the lentils are at a temperature in the range 10°C to 20°C; and the roller surface layer Shore A durometer hardness is in the range 65 to 85.
8. A method for de-hulling lentils, each comprising a kernel covered by a hull, the kernel consisting of a pair of united halves or 'splits', and splitting the hulled kernel into splits, comprising:
passing lentils at ambient temperature through a pair of opposed, cylindrical, gapped, downwardly rotating, driven rollers, each having an elastic, resilient circumferential surface layer, the rollers being rotated at different speeds, the Shore A durometer hardness of the roller surface layers, the gap between the rollers, the roller speeds and their differential in speed being collectively operative so as to substantially remove the lentil hulls and produce hulled kernels;
heating and drying the kernels to at least 30°C, to produce kernels amenable to splitting; and passing the produced kernels through a pair of opposed, cylindrical, gapped, downwardly rotating, driven rollers, each having an elastic, resilient circumferential surface layer, the rollers being rotated at different speeds, the Shore A durometer hardness of the roller surface layers, the gap between the rollers, the roller speeds and their differential in speed being collectively operative so as to split the kernels into splits.
passing lentils at ambient temperature through a pair of opposed, cylindrical, gapped, downwardly rotating, driven rollers, each having an elastic, resilient circumferential surface layer, the rollers being rotated at different speeds, the Shore A durometer hardness of the roller surface layers, the gap between the rollers, the roller speeds and their differential in speed being collectively operative so as to substantially remove the lentil hulls and produce hulled kernels;
heating and drying the kernels to at least 30°C, to produce kernels amenable to splitting; and passing the produced kernels through a pair of opposed, cylindrical, gapped, downwardly rotating, driven rollers, each having an elastic, resilient circumferential surface layer, the rollers being rotated at different speeds, the Shore A durometer hardness of the roller surface layers, the gap between the rollers, the roller speeds and their differential in speed being collectively operative so as to split the kernels into splits.
9. The method as set forth in claim 8 wherein the kernels are heated and dried to a temperature in the range 30°C - 41°C and, while at that temperature, are split.
10. The method as set forth in claim 9 comprising:
feeding the lentils to the gap between the rollers in the form of a sheet of lentils, said sheet being only one lentil thick; and feeding the hulled kernels to the gap between the rollers in the form of a sheet of kernels, said sheet being only one kernel thick.
feeding the lentils to the gap between the rollers in the form of a sheet of lentils, said sheet being only one lentil thick; and feeding the hulled kernels to the gap between the rollers in the form of a sheet of kernels, said sheet being only one kernel thick.
11. The method as set forth in claim 10 wherein:
the rollers have a Shore A durometer hardness in the range 60 to 85;
the rollers are gapped to provide a gap spacing in the range 20/1000 to 30/1000 of an inch; and the rollers are operated at a rotational speed differential in the range 56 to 61 %.
the rollers have a Shore A durometer hardness in the range 60 to 85;
the rollers are gapped to provide a gap spacing in the range 20/1000 to 30/1000 of an inch; and the rollers are operated at a rotational speed differential in the range 56 to 61 %.
12. Apparatus for de-hulling lentils, each comprising a kernel covered by a hull, to produce whole kernels, comprising:
a pair of opposed, cylindrical, gapped, downwardly rotatable rollers;
each roller having an elastic, resilient circumferential surface layer formed of material having a Shore A durometer hardness in the range of 60 -85;
the rollers having a gap in the range 20/1000 to 30/1000 of an inch;
and means for individually rotating each roller so that the rollers may be operated at a rotational speed differential.
a pair of opposed, cylindrical, gapped, downwardly rotatable rollers;
each roller having an elastic, resilient circumferential surface layer formed of material having a Shore A durometer hardness in the range of 60 -85;
the rollers having a gap in the range 20/1000 to 30/1000 of an inch;
and means for individually rotating each roller so that the rollers may be operated at a rotational speed differential.
13. The apparatus as set forth in claim 12 comprising:
means for feeding lentils along the length of the roller gap at its upper end in the form of a layer of lentils, one lentil in thickness.
means for feeding lentils along the length of the roller gap at its upper end in the form of a layer of lentils, one lentil in thickness.
14. The apparatus as set forth in claim 13 comprising:
a curved, flat chute, having top, bottom and side walls and extending along the length of the gap at its lower end, for receiving hulled kernels and conveying them to a delivery point.
a curved, flat chute, having top, bottom and side walls and extending along the length of the gap at its lower end, for receiving hulled kernels and conveying them to a delivery point.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US15976799P | 1999-10-15 | 1999-10-15 | |
| US60/159,767 | 1999-10-15 | ||
| PCT/CA2000/001203 WO2001028686A1 (en) | 1999-10-15 | 2000-10-13 | Process and apparatus for de-hulling and splitting lentils |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2386243A1 true CA2386243A1 (en) | 2001-04-26 |
Family
ID=22573939
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002386243A Abandoned CA2386243A1 (en) | 1999-10-15 | 2000-10-13 | Process and apparatus for de-hulling and splitting lentils |
Country Status (3)
| Country | Link |
|---|---|
| AU (1) | AU778710B2 (en) |
| CA (1) | CA2386243A1 (en) |
| WO (1) | WO2001028686A1 (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103182335B (en) * | 2011-12-27 | 2014-11-26 | 刘祝伟 | Agricultural peeling machine |
| JP6255800B2 (en) * | 2013-08-26 | 2018-01-10 | 井関農機株式会社 | Hulling sorter |
| CN107009657A (en) * | 2016-01-27 | 2017-08-04 | 天津市国民制药机械有限公司 | One kind rolls roll driving apparatus |
| JP2020152749A (en) * | 2019-03-18 | 2020-09-24 | 株式会社白形傳四郎商店 | Tea seed oil producing method and shell fruit seed shelling device used for it |
| CN110801880B (en) * | 2019-11-26 | 2021-05-04 | 衡阳市祥福米业有限责任公司 | Brown rice processing device and brown rice processing method |
| CN112076816B (en) * | 2020-08-12 | 2021-10-01 | 邵阳县兴隆粮油食品有限公司 | Corn processingequipment |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2236676A1 (en) * | 1972-07-26 | 1974-02-07 | Schule Gmbh F H | MACHINE FOR SEALING CEREALS |
| GB2195227B (en) * | 1986-09-17 | 1990-09-12 | John Archibald Ramsay Tainsh | Multi-crop seed decorticator |
| JPH0372960A (en) * | 1989-08-11 | 1991-03-28 | Satake Eng Co Ltd | Hulling roll of huller |
| JPH1033997A (en) * | 1996-07-22 | 1998-02-10 | Satake Eng Co Ltd | Hulling apparatus |
-
2000
- 2000-10-13 AU AU78945/00A patent/AU778710B2/en not_active Ceased
- 2000-10-13 WO PCT/CA2000/001203 patent/WO2001028686A1/en active IP Right Grant
- 2000-10-13 CA CA002386243A patent/CA2386243A1/en not_active Abandoned
Also Published As
| Publication number | Publication date |
|---|---|
| AU7894500A (en) | 2001-04-30 |
| WO2001028686A1 (en) | 2001-04-26 |
| AU778710B2 (en) | 2004-12-16 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| FZDE | Discontinued |