WO2018097706A2

WO2018097706A2 - Kernel nut and mesocarp separation system

Info

Publication number: WO2018097706A2
Application number: PCT/MY2017/050075
Authority: WO
Inventors: Gregory L FOSTER; Robiah Yunus
Original assignee: Foster Gregory L; Robiah Yunus
Priority date: 2016-11-28
Filing date: 2017-11-27
Publication date: 2018-05-31
Also published as: WO2018097706A3

Abstract

The present invention relates to a system and a method for separating a mesocarp surrounding a kernel nut of a fruitlet. The system essentially comprises a mesocarp removal assembly which has a rotatable shaft having a proximal end for connection to a driving assembly; a tapered helical screw disposed along the rotatable shaft for conveying the fruitlet along a helical path towards the proximal end of the rotatable shaft; and a plurality of tubular members of different outer diameters arranged in a stack defining a tapered chamber for enclosing the tapered helical screw thereof. Each of the plurality of tubular members comprises a side wall having openings with protruding cutting faces extending towards the rotatable shaft. The protruding cutting faces, as the fruitlet moves along the helical path of the tapered helical screw, lacerate the mesocarp to thereby displace the same through the openings into a surrounding cavity outside the tapered chamber.

Description

KERNEL NUT AND MESOCARP SEPARATION SYSTEM

FIELD OF THE INVENTION The present invention relates generally to arrangement for processing fruits having mesocarps and kernel nuts. More particularly, the present invention relates to a system and a method for separating the mesocarp surrounding the kernel nut of fruitlets, especially the oil palm fruitlets. BACKGROUND OF THE INVENTION

A Fresh Fruit Bunch (FFB) is comprised of a main stork, spikelet and individual fruit attached to the spikelet. After sterilization, the fruit is removed from the bunch to expose the stork and spikelet (rachis) and once removed what remains is thereafter defined as the Empty Fruit Bunch (EFB). The EFB is generally discarded or processed to remove attached oil and as a source of boiler fuel.

The fruit removed from the rachis after sterilization is comprised of the mesocarp and the kernel nut. The mesocarp contains oil entrapped within alpha cellulosic carbohydrates surrounded by hemi-cellulosic carbohydrates, rigid lignin fibre and water. With efficient sterilization and subsequent digestion, some oil is released as virgin oil and much of the hemi cellulosic carbohydrates (polysaccharides) are broken down to more simple sugars, Pentose and Hexose by water and heat induced hydrolysis while the lignin, kernel nut and alpha cellulosic carbohydrate entrapping the remaining oil, rely on a subsequent processing method (pressing or centrifuging) to extract the oil from the mesocarp. Several methods including, spinning, batch hydraulic pressing and continuous screw pressing all of which involve the application of an external force on the digested mesocarp material can be used to mechanically rupture the alpha cellulosic oil cell wall and liberate the oil from the mesocarp. Contemporary extraction methods rely mainly on continuous pressing, a process which is capable of exerting pressures in excess of 75 kg/cm². However, the maximum force that can be applied to the digested mesocarp is limited by the maximum force the kernel nut can withstand before fracturing. Once the kernel nuts begin to fracture the complete destruction of the kernel nut shell (endocarp) is imminent causing valuable kernel oil to be mixed with the crude oil. Kernel nut loss during pressing can be as high as 15 percent and result in a significant loss of revenue to the industry. For as long as kernel nuts are part of the digested mash, press force and pressure settings will remain as a delicate balance between optimizing crude oil extraction and minimizing kernel oil loss. Too much applied force on the one hand results in nut breakage as described, while too little applied force causes oil loss as high as 1 -2 percent of the total FFB processed. While an applied centrifugal force delivering an applied pressure of 10 kg/cm² is reasonably effective at rupturing alpha cellulosic material, continuous screw presses are capable of exerting significantly higher pressures as discussed. However the limiting factor for the applied pressure exerted by mechanical helical single or twin screws is ultimately that pressure when kernel nuts begin to fracture. Those familiar with the process readily identify that pressure as 50 kg/cm². This limits the effectiveness of the continuous press which relies on high pressure (in excess of 50kg/cm²) to maximize oil extraction. While the continuous screw press is capable of exerting significantly higher pressures which directly correlate to increased oil being squeezed from the mesocarp, it is limited by kernel nut losses as described. Before the limitations of the pressing process can be fully addressed, the kernel nut must be removed from the digested mash before pressing to avoid kernel oil losses due to kernel nut breakage and excessive crude oil losses due to tempered pressing.

A fundamental objective and a sign of complete digestion is the separation of the mesocarp from the kernel nut. To achieve this objective, there are many different processes and systems available in the art. For example, the digestion process has traditionally relied on a number of rotating blades generally 8 units, set equally along a central rotating drive shaft to slice and mash the fruit. The process is intended to separate the kernel nut and the mesocarp fibre, break- down the hemicelluloses surrounding the oil contained within the alpha-celluloses and hydrate the mesocarp. In the process, oil cells are ruptured and virgin oil flows from the mass as a result. This oil, along with short Non-Oily-Solids (NOS) can be drained from the base of the digester. The temperature should be maintained at approximately 95°C and the material should reside within the chamber exposed to the rotating blades for approximately 40 min for optimum result. By the end of the process the fruit is converted to a digested mash, a mixture of kernel nuts, cellulosic fibre material, water, crude oil and debris mainly silica sand. However, as the process is designed to continuously flow into the adjoining screw press the fruit often only resides in the digestion chamber for less than the optimum period of time only partially achieving the objective. Incomplete digested material demands the application of higher pressure in the subsequent pressing operation to rupture un-ruptured oil bearing cells. This in turn increases kernel nut breakage and the commencement of an unending cycle of extraction process losses.

A need therefore exists for an improved system and method that induces the separation of the kernel nut and the mesocarp in a controlled manner thereby overcoming the problems and shortcomings of the prior art. Although there are methods and systems for the same in the prior art that have grown tremendously, for many practical purposes, there is still considerable room for improvement.

SUMMARY OF THE INVENTION

The following presents a simplified summary of the invention in order to provide a basic understanding of some aspects of the invention. This summary is not an extensive overview of the invention. Its sole purpose is to present some concepts of the invention in a simplified form as a prelude to the more detailed description that is presented later. It is an object of the present invention to provide an improved system and method for removal of the kernel nut before pressing the mesocarp. The present invention suggests that the kernel nut is removed prior to pressing in a kernel nut mesocarp separation and digestion system. Accordingly, the present invention provides a system for separating mesocarp surrounding kernel nut of a fruitlet.

The system of the present invention can be characterized by a mesocarp removal assembly. The mesocarp removal assembly comprises a rotatable shaft having a proximal end for connection to a driving assembly; a tapered helical screw disposed along the rotatable shaft for conveying the fruitlet along a helical path towards the proximal end of the rotatable shaft; and a plurality of tubular members of different outer diameters arranged in a stack defining a tapered chamber for enclosing the tapered helical screw thereof, wherein each of the plurality of tubular members comprises a side wall having openings with protruding cutting faces extending towards the rotatable shaft, whereby the protruding cutting faces, as the fruitlet moves along the helical path of the tapered helical screw, lacerate the mesocarp to thereby displace the same through the openings into a surrounding cavity outside the tapered chamber.

Preferably, the system further comprises a kernel nut washing chamber disposed towards the proximal end of the rotatable shaft and is relative to the mesocarp removal assembly. The kernel nut washing chamber comprises rotatable fingers and fixed fingers attached to the rotatable shaft configured for retaining the kernel nut, the mesocarp of which is detached therefrom, conveyed by the tapered helical screw; and a water nozzle attached to the rotatable shaft configured for spraying water to the kernel nut retained in the kernel nut washing chamber to remove residual mesocarp fiber and oil. Preferably, the system further comprises a kernel nut collection assembly coupled to the kernel nut washing chamber comprising a plurality of kernel nut chutes configured for receiving and collecting the kernel nut thereof.

Preferably, the system further comprises a mesocarp collection assembly disposed towards the proximal end of the rotatable shaft and is relative to the surrounding cavity outside the tapered chamber. The mesocarp collection assembly comprises a perforated plate having holes coupled to the rotatable shaft configured for filtering the mesocarp falling through the surrounding cavity from a residual matter; a skimming arm rotatable relative to a central axis of the rotatable shaft configured for sweeping the mesocarp falling on the perforated plate to a mesocarp discharge chute; and a steam injection ring configured for discharging a steam on a continuous manner to a vessel that is connected to the perforated plate thereof. Preferably, the driving assembly comprises a spur drive gear mounted to the proximal end of the rotatable shaft; and a hydraulic motor provided with a gear box coupled thereto configured for driving the spur drive gear. Preferably, the mesocarp removal assembly comprises a high pressure water nozzle coupled to the rotatable shaft through a rotary coupling configured for spraying high pressure, hot water towards the side wall of the plurality tubular members. Preferably, the system further comprises an internal casing and an external insulation casing surrounding the internal casing.

Preferably, the protruding cutting faces comprises sharp edges that are integrally formed from the side wall of the plurality of tubular members, the deformation of which defines the openings thereof.

Preferably, the protruding cutting faces and the openings are aligned in a spiral manner along the side wall. Preferably, each of the protruding cutting faces comprises a saw blade with series of teeth extending along a length of the plurality of tubular members.

Preferably, the side wall comprises a plurality of saw blades circumferentially spaced apart from each other with a gap therebetween that defines the openings thereof.

Preferably, the tapered chamber of the plurality of tubular members corresponds to that of the tapered helical screw. In accordance with another aspect of the present invention, there is provided a method of separating mesocarp surrounding kernel nut of a fruitlet.

The method of the present invention can be characterized by the steps of receiving and conveying the fruitlet along a helical path of a tapered helical screw that is coupled to a rotatable shaft; and as the fruitlet moves along the helical path, lacerating the mesocarp using protruding cutting faces that extend from a side wall of a plurality of tubular members of different outer diameters arranged in a stack defining a tapered chamber towards the rotatable shaft to thereby displace the same through openings at the protruding cutting faces into a surrounding cavity outside the tapered chamber.

It is therefore an advantage of the present invention that utilizes the fracture resistance of the kernel nuts to displace the softer mesocarp fibre after laceration thereby segregating the kernel nut from the mesocarp for discharge prior to the pressing operation. This ensures no nuts are lost or broken and a significantly higher Palm Kernel Oil (PKO) recovery.

It is therefore another advantage of the present invention that the removal of nuts prior to pressing allows considerably higher pressures to be exerted on oil bearing fibre by the subsequent pressing operation. Because kernel nuts are removed prior to pressing the physical size and capacity of the subsequent screw press is significantly reduced as the volume of nuts, approximately 38 percent were removed from the digested mash entering the screw press. It is therefore yet another advantage of the present invention that the tapered helical screw introduces a pre-pressing stage to the traditional digester/screw press process which induces the separation of the kernel nut and the mesocarp in a controlled manner regardless of how intermittent fruit is arriving to the combined kernel nut mesocarp separation and digestion system thereby guaranteeing a controlled amount of fruit exposed to the cutting faces protruding from the tapered chambers.

It is therefore yet another advantage of the present invention that the injection of an abundance of high pressure hot water spray not only washes the kernel nut to remove residual oil and fibre attached but causes the lacerated fibrous material to pass through the empty spaces defined by the circumferentially assembled cutting blades which make up the defining circumference of the tapered chamber and provides sufficient water to promote a secondary hydrolysis effect. The foregoing and other objects, features, aspects and advantages of the present invention will become better understood from a careful reading of a detailed description provided herein below with appropriate reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of the invention and many of the attendant advantages thereof will be readily as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:

Figure 1 shows a system for separating mesocarp surrounding kernel nut of fruitlet according to one embodiment of the present invention ;

Figure 2 shows a system for separating mesocarp surrounding kernel nut of fruitlet with the external insulation casing removed according to one embodiment of the present invention ; Figure 3 shows a system for separating mesocarp surrounding kernel nut of fruitlet with the internal casing removed according to one embodiment of the present invention ;

Figure 4a shows a tapered helical screw disposed along the rotatable shaft according to one embodiment of the present invention;

Figure 4b shows a rotary coupling connected to the rotatable shaft according to one embodiment of the present invention; Figure 5a illustrates a plurality of tubular members of different outer diameters arranged in stack defining a tapered chamber according to one embodiment of the present invention ;

Figure 5b illustrates a perforated tubular member with support frame according to one embodiment of the present invention; Figure 5c illustrates a side wall of the tubular member that has openings with protruding cutting faces according to one embodiment of the present invention;

Figure 6a illustrates a plurality of tubular members of different outer diameters arranged in stack defining a tapered chamber according to another embodiment of the present invention;

Figure 6b illustrates a tubular chamber with support frame according to another embodiment of the present invention;

Figure 6c illustrates a side wall of the tubular chamber that has openings with protruding cutting faces according to another embodiment of the present invention; Figures 7a and 7b show a kernel nut washing chamber that includes rotatable fingers, fixed fingers and water nozzle attached to the rotatable shaft according to one embodiment of the present invention;

Figure 8a shows a kernel nut collection assembly that comprises a plurality of kernel nut chutes according to one embodiment of the present invention;

Figure 8b shows a mesocarp collection assembly that comprises a perforated plate, a skimming arm, a mesocarp discharge chute and a steam injection ring according to one embodiment of the present invention;

Figures 8c-a and 8c-b show a skimming arm suitable for use with the perforated plate according to one embodiment of the present invention;

Figure 8d shows a steam injection ring deployed at the mesocarp collection assembly according to one embodiment of the present invention; and

Figure 9 shows a driving assembly that comprises a spur drive gear and a hydraulic motor adapted for driving the rotatable shaft according to one embodiment of the present invention. It is noted that the drawings may not be to scale. The drawings are intended to depict only typical aspects of the invention, and therefore should not be considered as limiting the scope of the invention. In the drawings, like numberings represent like elements between the drawings.

DETAILED DESCRIPTION OF THE INVENTION

According to one preferred embodiment, the present invention discloses a system and a method for effective removal of the kernel nut from the mesocarp of the fruitlet prior to pressing in a kernel nut mesocarp separation and digestion system.

The system of the present invention comprises a mesocarp removal assembly 100, a kernel nut washing chamber 200, a kernel nut collection assembly 300, a mesocarp collection assembly 400 and a driving assembly 500 as schematically shown in the accompanying drawings, particularly in Figure 3. Figure 1 of the present invention shows a complete system for the same with an external insulation casing 601 to house every components therein. Figure 2, on the other hand, shows the system of the present invention without the external insulation casing 601 , which further reveals an internal casing 600.

Essentially, the fruitlet which comprises a kernel nut surrounded by a mesocarp is introduced into the system of the present invention through the mesocarp removal assembly 100. The mesocarp removal assembly 100 preferably comprises a rotatable shaft 101 , a tapered helical screw 102 disposed along the rotatable shaft 101 and a plurality of tubular members 103 encasing the tapered helical screw 102. The rotatable shaft 101 has a proximal end for connection to the driving assembly 500. The tapered helical screw 102 provided along the rotatable shaft 101 is configured for conveying the fruitlet along a helical path towards the proximal end of the rotatable shaft 101 . The plurality of tubular members 103 is comprised of different outer diameters. The tubular members 103 are arranged in a stack that defines a tapered chamber 103a. The tapered chamber 103a which made of the stacked tubular members 103 is adapted to enclose the tapered helical screw 102 thereof. In terms of its structure, each of the tubular members has a side wall essentially along its circumference. On the side wall, openings 103b are formed together with protruding cutting faces 103c that extends inwardly towards the rotatable shaft 101.

Once the fruitlet is entered into the system, it is immediately exposed to the tapered helical screw 102. As the fruitlet moves along the helical path of the tapered helical screw 102, the protruding cutting faces 103c lacerate the mesocarp to thereby displace the same through the openings 103b into a surrounding cavity outside the tapered chamber 103a. The tapered helical screw 102is fabricated according to a fixed helix angle although it may be a requirement to vary the helix angle depending on the throughput objectives. The screw 102, as shown in Figure 4a, gradually reduces in diameter at one end as does the corresponding tapered chamber 103a. The tapered chamber 103a (see Figures 5a and 5b; and 6a and 6b) ensures that the opening at one end receiving the fruit is sufficiently larger in diameter than the smaller diameter at the exiting end of the mesocarp removal assembly 100 to induce sufficient force on the fruit moving through the chamber 103a to push the lacerated mesocarp through the tubular chamber 103 via its opening 103b. The tapered chamber 103a is comprised of a plurality of tubular members 103 of various outer diameters as mentioned which have a number of pierced cutting blades with sharp edges, as shown in Figures 5c and 6c.

According to one preferred embodiment of the present invention, with reference to Figure 5c, the protruding cutting faces 103c comprises sharp edges that are integrally formed from the side wall of the plurality of tubular members 103. The deformation of which defines the openings thereof 103b. In this regard, the protruding cutting faces 103c and the openings 103b are aligned in a spiral manner along the side wall. According to another preferred embodiment of the present invention, with reference to Figure 6c, each of the protruding cutting faces 103c comprises a saw blade with series of teeth extending along a length of the plurality of tubular members 103. The side wall preferably comprises a plurality of saw blades circumferentially spaced apart from each other with a gap therebetween. The gap therefore defines the openings thereof 103b. It is preferred that 90 percent of the forces created by the rotating tapered helical screw 102 acts in a vertical direction. The vertical saw blades increase the wall resistance to prevent the mesocarp turning with the screw 102. Essentially, the blades are all the same, although in some instances a smaller tooth configuration is being used for the bottom two chambers 103a as most of the mesocarp is removed in the first two chambers 103a. The gap between the saw blades has been increased significantly and therefore allows more mesocarp to pass unimpeded to the surrounding cavity of the chamber 103a. As the tapered helical screw 102 rotates, a volume of material is conveyed downward through the tapered chamber 103a. This volume of material is comprised of individual fruitlet and as the fruitlet is conveyed downward, it is increasingly lacerated by the exposed cutting faces 103c protruding from the tubular chamber 103.

The forces induced by the screw 102 act to displace lacerated mesocarp through the tubular member wall openings 103b into the surrounding cavity thereafter falling to the bottom of the tapered chamber 103a. The openings 103b are of sufficient dimension to allow only the passage of the mesocarp fibre and liquids but not the kernel nuts. As the tapered helical screw 102 conveys downwards, it forces the fruit towards the exposed cutting faces 103c due to forces imposed by the reducing diameter of the tapered chamber 103a set subjecting the fruit to multiple lacerations. As the softer mesocarp volume is continuously lacerated and torn away from the kernel nuts, it is increasingly displaced by the fixed volume of kernel nuts unable to pass through the tubular member openings 103b. Progressively, the tapered helical screw 102 forces the kernel nuts to occupy reducing tubular member volumes towards the bottom of the tapered chamber 103a set till the kernel nuts enter the bottom/final tubular member where only sufficient tubular member volume exists to accommodate the accumulated volume of kernel nuts being approximately 38 percent of the entering fruit volume.

Each tapered helical screw flight is fitted with a high pressure water nozzle 104 to spray hot water at high pressure as it is pumped into the rotatable shaft 101 at the centre of the tapered helical screw 102 via a rotary coupling 105. The rotary coupling 105 is shown in Figure 4b. The high pressure hot water spray aids in the passage of detached mesocarp through the tubular member openings 103b and the removal of residual mesocarp fibre and oil attached to the kernel nut. Kernel nuts exiting the mesocarp removal assembly 100 pass into and through the kernel nut washing chamber 200 as shown in Figure 7a. The kernel nut washing chamber 200 which is disposed towards the proximal end of the rotatable shaft 101 is comprised of a series of rotating fingers 201 and static or fixed fingers 202. The finger configuration (see Figure 7b) is designed to retain and restrict the movement of kernel nuts thereby increasing the exposure of the kernel nuts to a final water spray via a water nozzle 203 to remove residual mesocarp fibre and oil attached to the kernel nuts before they exit. The kernel nuts exit the washing chamber 200 through a plurality of kernel nut chutes 301 of a kernel nut collection assembly 300. The kernel nut chutes 301 is preferably further connected to a single collection chute (see, for example, the C-shaped chute in Figure 8a) fixed to the inner skin lining of a vessel 405.

Mesocarp exiting the tapered chambers 103a through the tubular member openings 103b into the surrounding cavity falls onto a perforated plate 401 of the mesocarp collection assembly 400 which is located at the base plate of the vessel 405. The perforated plate 401 as shown in Figure 8b are designed to allow the passage of water and oil plus smaller Non Oily Solids (NOS) but restrict the passage of bulkier mesocarp which is skimmed from the top of the perforated plate 405 by a skimming or expeller arm 402 which collects, deposits and expels the mesocarp into a mesocarp discharge chute 403 for subsequent pressing. The perforated plate 401 has a plurality of holes coupled to the rotatable shaft 101 . It can be configured for filtering the mesocarp fell thereof from a residual matter. The skimming arm 402 in Figures 8c-a and 8c-b is preferably rotatable relative to a central axis of the rotatable shaft 101 . It is worth to note that these Figures 8c-a and 8c-b illustrate two different types of skimming or expeller arm 402 that both are suitable to be used in the present invention. It can be configured for sweeping the mesocarp on the perforated plate 401 so that the mesocarp is directed to the mesocarp discharge chute 403. Steam at approximately 3.5 barg is continuously discharged into the vessel 405 via a steam injection ring 404 (see Figure 8d). Torque is transmitted from the driving assembly 500, particularly from a hydraulic motor 502 connected to a spur drive gear 501 (see Figure 9). The spur drive gear 501 is mounted to the proximal end of the rotatable shaft 101. The hydraulic motor 502 is preferably provided with a gear box coupled thereto configured for driving the spur drive gear 501. It should be noted that other types of gearboxes can be used to achieve the necessary rotational speed of the helical spiral.

The system of the present invention is designed for easy removal of the internal wear components, i.e. the tapered helical screw 102, the tubular members 103.

The terms "a" and "an," as used herein, are defined as one or more than one. The term "plurality," as used herein, is defined as two or more than two. The term "another," as used herein, is defined as at least a second or more. The terms "including" and/or "having," as used herein, are defined as comprising (i.e., open language).

While this invention has been particularly shown and described with reference to the exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention as defined by the appended claims.

Claims

1 . A system for separating mesocarp surrounding kernel nut of a fruitlet, characterized in that, the system comprising :

a mesocarp removal assembly, comprising:

a rotatable shaft having a proximal end for connection to a driving assembly;

a tapered helical screw disposed along the rotatable shaft for conveying the fruitlet along a helical path towards the proximal end of the rotatable shaft; and

a plurality of tubular members of different outer diameters arranged in a stack defining a tapered chamber for enclosing the tapered helical screw thereof, wherein each of the plurality of tubular members comprises a side wall having openings and protruding cutting faces extending towards the rotatable shaft, whereby the protruding cutting faces, as the fruitlet moves along the helical path, lacerate the mesocarp to thereby displace the same through the openings into a surrounding cavity outside the tapered chamber.

2. The system according to Claim 1 further comprising:

a kernel nut washing chamber disposed towards the proximal end of the rotatable shaft and is relative to the mesocarp removal assembly, comprising : rotatable fingers and fixed fingers attached to the rotatable shaft configured for retaining the kernel nut, the mesocarp of which is detached therefrom, conveyed by the tapered helical screw; and

a water nozzle attached to the rotatable shaft configured for spraying water to the kernel nut retained in the kernel nut washing chamber to remove residual mesocarp fiber and oil.

3. The system according to Claim 2 further comprising :

a kernel nut collection assembly coupled to the kernel nut washing chamber comprising a plurality of kernel nut chutes configured for receiving and collecting the kernel nut thereof.

4. The system according to Claim 1 further comprising:

a mesocarp collection assembly disposed towards the proximal end of the rotatable shaft and is relative to the surrounding cavity outside the tapered chamber, comprising:

a perforated plate having holes coupled to the rotatable shaft configured for filtering the mesocarp falling through the surrounding cavity from a residual matter;

a skimming arm rotatable relative to a central axis of the rotatable shaft configured for sweeping the mesocarp falling on the perforated plate to a mesocarp discharge chute; and

a steam injection ring configured for discharging a steam on a continuous manner to a vessel that is connected to the perforated plate thereof.

5. The system according to Claim 1 , wherein the driving assembly comprises: a spur drive gear mounted to the proximal end of the rotatable shaft; and a hydraulic motor provided with a gear box coupled thereto configured for driving the spur drive gear.

6. The system according to Claim 1 , wherein the mesocarp removal assembly comprises a high pressure water nozzle coupled to the rotatable shaft through a rotary coupling configured for spraying high pressure, hot water towards the side wall of the plurality tubular members.

7. The system according to Claim 1 further comprising an internal casing and an external insulation casing surrounding the internal casing.

8. The system according to Claim 1 , wherein the protruding cutting faces comprises sharp edges that are integrally formed from the side wall of the plurality of tubular members, the deformation of which defines the openings thereof.

9. The system according to Claim 8, wherein the protruding cutting faces and the openings are aligned in a spiral manner along the side wall.

10. The system according to Claim 1 , wherein each of the protruding cutting faces comprises a saw blade with series of teeth extending along a length of the plurality of tubular members.

1 1 . The system according to Claim 1 0, wherein the side wall comprises a plurality of saw blades circumferentially spaced apart from each other with a gap therebetween that defines the openings thereof.

12. The system according to Claim 1 , wherein the tapered chamber of the plurality of tubular members corresponds to that of the tapered helical screw.

13. A method of separating mesocarp surrounding kernel nut of a fruitlet, characterized in that, the method comprising the steps:

receiving and conveying the fruitlet along a helical path of a tapered helical screw that is coupled to a rotatable shaft; and

as the fruitlet moves along the helical path, lacerating the mesocarp using protruding cutting faces that extend from a side wall of a plurality of tubular members of different outer diameters arranged in a stack defining a tapered chamber towards the rotatable shaft to thereby displace the same through openings at the protruding cutting faces into a surrounding cavity outside the tapered chamber.