AU638294B2 - Selective coffee pulper - Google Patents

Description

638294 COMMONWEALTH OF AUSTRALIA Patents Act 1952 S* Name of Applicant S. Address of Applicant •co Actual Inventor Address for Service c. 0 THE STATE OF QUEENSLAND Department of Primary Industries, Primary Industries Building, 80 Ann Street, Brisbane, Queensland, 4000,

AUSTRALIA.

Christopher Paul NORRIS GRANT ADAMS COMPANY Patent Trade Mark Attorneys Level 9 NATIONAL MUTUAL CFSITRE 144 Edward Street Brisbane, Queensland, 4000

AUSTRALIA.

b S q 03 3 COMPLETE SPECIFICATION FOR THE INVENTION ENTITLJE: "SELECTIVE COFFEE PULPER" The following statement is a full description of the invention including the best method of performing it known to the applicant.

THIS INVENTION relates to a selective coffee pulper. The invention also relates to the selective pulping of other fruits or berries where the seeds or beans are to be harvested.

A. Coffee "Wet" Processing "Wet" processing is the method used for the production of high quality arabica coffee. Ripe coffee cherry is "pulped" to remove the outer skin or "pulp", then fermented to remove the mucilage which surrounds each bean and finally washed and dried for storage as parchment coffee.

Current commercial pulping systes (both disc and drum types) feed cherry into a chamber where it is 1 confined against a roughened surface on a rotating disc 15 (or drum).

The cherry is ruptured and the pulp is torn from the beans. The beans can then escape from the S. pulping chamber past an adjustable "gate". Ripe coffee cherries pulp easily and so the residence time in a pulper is short, throughput high and damage to coffee beans low.

When immature coffee cherries are introduced So with the ripe cherry, a number of problems can occur:- S( a) because immature coffee cherries do not 25 "pulp" in the conventional sense of the word, they are retained in the pulping chamber until they are broken or abraided down to a size where they can "escape" with the pulped bean; this can significantly reduce pulper throughput because of the increased residence time of the cherry in the pulping chamber; this increased residence time of material in the pulping chamber increases potential for damage to the parchment of mature pulped coffee beans; and having passed through the pulper, it is then very difficult to separate the pieces of immature bean and cherry from the mature bean by any simple physical method.

For maximum final product quality, low tolerance exists on the amount of pulped immature cherry which is allowed in subsequent processing stages.

To produce high quality coffee, it is normal to hand sort the immature cherry from hand harvested cherry prior to pulping.

Early results with machine harvested coffee for wet processing show that in excess of 30% of the produce ex-harvester can be immature cherry. Hand sorting is impractical in a highly mechanized operation.

Electronic colour sorting is prohibitively expensive if the necessary throughput is to be ach Leved in a 15 commercial operation.

B. Potential for Selective Pulping As a coffee cherry matures, the layer between

S.

the parchment (on the bean) and the outer skin and between the beans, changes from a high strength high density stabilized layer to a low strength mucilaginous layer. Similarly, the outer skin softens, thickens and changes from green to red.

Therefore, as the coffee matures, its ability to withstand external forces and remain intact reduces 25 as the mucilaginous layer is of low strength and also displays a lubricant effect. Thus, if a ripe cherry is squeezed, the pulp will rupture and the beans can be easily expelled. Within an immature cherry, the force required to achieve this effect rises dramatically.

The present invention is designed to exploit the physical change in the cherries as they mature.

It :is an object of the present invention to provide a selective pulper where the ripe cherries are pulped but the immature cherries remain intact.

It is a preferred object to provide a pulper which has a relative high throughput.

It is a further preferred object to provide a pulper which is readily mobile and which can be operated by unskilled labour.

Other preferred objects of the present invention will become apparent from the following decription.

In one aspect, the present invention resides in a selective pulper for coffee cherries or the like including: a frame; at least one solid drum or roller rotatably mounted on the frame; at least one resilient wheel, drum or roller rotatably mounted on the frame in contact with the solid drum or roller; and means to drive the solid drum or roller and the resilient wheel, drum or roller in opposite directions of rotation at different peripheral speeds; the pressure between the roller and the 0: 20 resilient wheel, drum or roller being so arranged that o as coffee cherries pass therebetween, ripe cherries are pulped to release the seed or bean from the pulp but immature cherries remain intact.

Two or more resilient wheels, drums or rollers 25 may be provided in series with the solid drum or roller, so that the cherries pass between the solid drum and the oo. respective wheels, and ripe cherries not pulped by the first wheel will be pulped by the second or subsequent wheels.

In a second aspect, the present invention resides in a selective pulper for coffee cherries or the like including: a frame; at first solid drum or roller rotatably mounted on the frame; a second solid drum or roller rotatably mounted on spring-loaded journals in resilient contact with the first solid drum or roller; and means to drive the first and second solid drums or rollers in opposite directions of rotation at different peripheral speeds; the pressure between the first and second solid drums or rollers being so arranged that as coffee cherries pass therebetween, ripe cherries are pulped to release the seed or bean from the pulp but immature cherries remain intact.

In a third aspect, the present invention resides in a selective pulper for coffee cherries or the like including: a frame; a first solid drum or roller rotatably i mounted on the frame; a second solid drum or roller rotatably mounted on the frame; 20 a resilient belt having a run passing oo. between, and at least partially compressed by, the solid drums or rollers; means to drive the solid drums or rollers in opposite directions of rotation and at different 25 peripheral speeds, the run of the belt travelling at the peripheral speed of the second solid drums or rollers; the pressure between the first solid drum or roller and the run of the belt being so arranged that as coffee cherries pass therebetween, the ripe cherries are pulped to release the seed or bean from the pulp but immature cherries remain intact.

The resilient belt may be supported on head and tail pulleys rotatably mounted on the frame. The pulleys, may be mounted above and below the second solid drum or roller so that the belt tends to partially wrap around the second solid drum or roller.

In a fourth aspect, the present invention resides in a selective pulper for coffee cherries or the like including: a frame; a first solid drum or roller rotatably mounted on the frame; a resilient belt supported on rollers on the frame and having a run in engagement with the first sold drum or roller; and means to drive the first solid drum or roller and the resilient belt in opposite directions of rotation at different peripheral speeds; the pressure between the first solid drum or roller and the run of the resilient belt being so arranged that as the coffee cherries pass therebetween, ripe cherries are pulped to release the seed or bean from the pulp but immature cherries remain intact.

Preferably the solid drum and the resilient 20 drum, roller, wheel or belt, or the second solid drum, rotate at different peripheral speeds to promote rotation of the cherries as they are "squeezed" to ensure the best rupture plane between the beans in the cherries is achieved and to enhance removal of beans 25 from the pulp.

The aggressiveness of the pulping action may be controlled by the speed differential, the loadig pressure between the drums, rollers etc., and the stiffness of tie resilient surfaces. With the resilient wheels, the pressure on the cherries may be varied by varying the pressure in the pneumatic tyre on the wheel.

The resiliency is preferably selected so that ripe cherries do not escape pulping when in close proximity to immature cherries.

Preferably the mature beans are removed from the immature cherries and the pulp by conventional screening techniques.

To enable the invention to be fully understood, a preferred embodiment will now be described with reference to the accompanying drawings, go..

6:044 in which: FIG 1 is a perspective front view of a prototype pulper; FIG. 2 is a schematic side view of the drum and wheels; FIG. 3 is a- top plan view of the drum and wheels; and FIG. 4 is a perspective rear view of the drive of the pulper.

The pulper 10 has a frame 11 with two pairs of vertical uprights 12, 13 and 14, 15 welded to respective horizontal feet 16, 17.

-A solid drum 18, with side plates 19, has an axle 20 rotatably journalled in bearing blocks 21 on the 15 frame.

gemS Respective upper and lower wheels 22, 23 are mounted on axles 24, 25 rotatably journalled in bearing blocks 26, 27 on the frame. Each wheel 22, -23 has respective tyre 28, 29 in contact with, and partially compressed by, the drum 18.

The axle 24 of the upper wheel 22 is provided with a pulley 30 connected by a belt 31 to an output pulley 32 on an electric motor 33 mounted on the frame 31.

25 A sprocket 34 on the other end of the axle 24 drives a chain 35 which passes around sprockets 36, 37, 38 on axles 20, 25 and an idler shaft 39 (journalled in S. bearings 40 on the frame). The drum 18 is driven in c -fhe opposite direction to the wheels 22, 23 and the drum 18 and wheels 22, 23 are preferably rotated at different speeds, eg. 122 rpm: 134 rpm: 140 rpm (see FIG. 2).

The coffee cherries are fed between the drum 18 and the tyre 28 in the direction of the arrow A in FIG. 2 from a hopper 41 mounted on the frame with a discharge outlet 42. The pulped cherries are collected 7 A] in an open-topped tank 43 which has a liquid outlet 44.

As stated above, the coffee cherries are fed from the hopper 41 between the drum 19 and upper tyre 28 in' the direction of arrow A. As they pass between the drum and tyre, they are rolled. The pressure applied to the pulp of the ripe cherries causes it (and the outer skin) to be ruptured or pulped to release the coffee \beans contained therein. The procedure is repeated bet en the drum 18 and the lower tyre 29. The pressure between the drum and the tyres is not sufficient to pulp the immature cherries and they pass through the pulper intact. The resilience of the tyres 18, 29 ensures that even ripe cherries adjacent immature cherries will be pulped.

15 The mature beans, pulp and immature cherries are collected below the pulper in the tank 43 and the mature beans are separated by conventional screening techniques.

Secret trials (by the Queensland Department of Primary Industries) at Walkamin Research Station have demonstrated the soundness of the concept. The prototype had a capacity significantly higher than that of a widely used small commercial drum pulper. The quality of the product was excellent with low levels of 25 damage to mature beans and almost no "pulping" of immature cherries, allowing their easy subsequent removal. The throughput and efficiency of pulping ripe chery was significantly less effected by increasing proportions of immature cherry than was the conventional pulper. At high levels of green cherry, damage to parchment of mature cherries was significantly less.

It will be readily apparent to the skilled addressee that the resilient roller, drum or wheel can be replaced by a resilient belt which may be backed by a solid drum or roller.

In a commercial machine, the rollers, drums, belts or wheels would be- of a suitable width for the desired throughput of cherries.

The drive to the axles may be by belts and pulleys, gears, chains and sprockets, hydraulic motors or the like and the speed differential between the axles may be variable.

The bearing blocks for at least one of the axles may be adjustably mounted on the frame to enable the pressure applied to the cherries to be varied and the bearing blocks may be spring-loaded "(with safety release means) if no rocks or a person arm attempts to pass between the rotating drums, rollers etc.

The pulper may be mounted on a trailer or other vehicle for transport to, and operational at, the 15 harvesting site or may be permanently mounted in a building.

ve* aWith the operation of the pulper, it is preferable that the parchment over the seed or bean is

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a. a a o II.L oU Jl .j o l pVI. .U .1 ClL ClJ 1 AJ.L COLl Once the pulper has been set, even unskilled workers will be able to operate the machine and achieve this result.

Various changes and modifications may be made to the embodiments described without departing from the scope of the present invention as defined in the appended claims.

Claims (10)

1. A selective pulper for coffee cherries or the like including: a frame; at least one solid drum or roller rotatably mounted on the frame; Sat least one resilient wheel, drum or roller rotatably mounted on the frame in contact with the solid drum or roller; and means to drive the solid drum or roller and the resilient wheel, drum or roller in opposite directions of rotation at different peripheral speeds; the pressure between the roller and the resilient wheel, drum or roller being so arranged that as coffee cherries pass therebetween, ripe-cherries are pulped to release the seed or bean from the pulp but :immature cherries remain intact. S"

2. A selective pulper according to Claim 1 wherein: 20 two or more resilient wheels, drums or rollers are. provided in series with the solid drum or roller, so arranged that cherries not pulped but the first resilient wheel, drum or roller will be pulped by the second or successive resilient wheels, drums or S 25 rollers.

3. A selective pulper according to Claim 2 wherein: *eeo the first and second resilient wheels, drums or rollers are driven at different peripheral speeds.

4. A selective pulper for coffee cherries or the like including: a frame; a first solid drum or roller rotatably mounted on the frame; a second solid drum or roller rotatably mounted on the frame; a resilient belt having a run passing between, and at least partially compressed by, the solid drums or rollers; means to drive the solid drums or rollers in opposite directions of rotation and at different peripheral speeds, the run of the belt travelling at the peripheral speed of the second solid drums or rollers; the pressure between the first solid drum or roller and the run of the belt being so arranged that as coffee cherries pass therebetween, the ripe cherries are pulped to release the seed or bean from the pulp but immature cherries remain intact.

A selective pulper according to Claim 4 wherein: the resilient belt is supported on head and tail pulleys, rotatably mounted on the frame, respectively above and below the second solid drum or S: roller, so that the resilient belt tends to partially 20 wrap around the second solid drum or roller.

6. A selective pulper for coffee cherries or the like including: a frame; at first solid drum or roller rotatably 25 mounted on the frame; Sa second solid drum or roller rotatably mounted on spring-loaded journals in resilient contact with the first solid drum or roller; and means to drive the first and second solid drums or rollers in opposite directions of rotation at different peripheral speeds; the pressure between the first and second solid drums or rollers being so arranged that as coffee cherries pass therebetween, ripe cherries are pulped to release the seed or bean from the pulp but immature 11 ii cherries remain intact.

7. A selective pulper for coffee cherries or the like including: a frame; a first solid drum or roller rotatably mounted on the frame; a resilient belt supported on rollers on the frame and having a run in engagement with the first sold drum orroller; and means to drive the first solid drum or roller and the resilient belt in opposite directions of rotation at different peripheral speeds; the pressure between the first solid drum or roller and the run of the resilient belt being so :.15 arranged that as the coffee cherries pass therebetween, ripe cherries are pulped to release the seed or bean from the pulp but immature cherries remain intact. o

8. A selective pulper as claimed in any one of Claims 1 to 7 wherein: 20 the different peripheral speeds promote rotation of the coffee cherries as they are "squeezed" to ensure the best ruptive plane between the seeds or beans and the pulp in the c.offee cherries and to enhance removal of the seeds or beans from the pulp,. S 25

9. A selective pulper as claimed in any one of Claims 1 to 8 wherein: the pressure applied to the coffee cherries is variable.

10. A selectivebpulper for coffee cherries or the 30 like substantally as hereinbefore described with reference to the accompanying drawings. DATED this fifteenth day of April 1993. THE STATE OF QUEENSLAND, by its Patent Attorneys, GRANT ADAMS COMPANY. 12