WO2014007602A1

WO2014007602A1 - Installation for treatment of oil palm fruits

Info

Publication number: WO2014007602A1
Application number: PCT/MY2013/000119
Authority: WO
Inventors: Heng Mun Lew
Original assignee: Heng Mun Lew
Priority date: 2012-07-03
Filing date: 2013-06-28
Publication date: 2014-01-09
Also published as: CN104470381B; AP2015008217A0; CN104470381A; IN2015DN00643A; CO7170128A2; BR112014032662B1; BR112014032662A2; MY159101A

Abstract

An installation for treatment of harvested palm fruits using pressurized steam comprises a sterilizer unit and a steam supply unit working in combination. The sterilizer unit includes a vessel (10) having inlet (12) for charging in fruits, steam openings (16a, 16b, 16c)) for receiving steam, outlet (14) for dispensing treated fruits and a pivot (20) for tilting the vessel to various orientations. The steam supply unit includes a shaft (28) fixedly mounted onto the pivot (20), a pipeline (30) connected to end of the shaft and used for supplying steam, a housing (32) connected to and rotatable about the pipeline, a flange (38) to retain the housing in position, and an elbow (54) connected to the housing such that the elbow can supply steam to the vessel from a fixed location.

Description

Installation for Treatment of Oil Palm Fruits

Technical Field

The invention relates to installation for treatment of freshly harvested oil palm fruits, more particularly concerning sterilization of palm fruits in vessels using pressurized steam.

Background Art

Freshly harvested oil palm fruits are subject to sterilization process to ensure that oil bearing parts are not contaminated, which would otherwise affect quality of the oil being extracted. The sterilization process is done in palm oil mills in special vessels, wherein the charged fruits are cooked over certain period of time by pressurized steam at pre-determined temperature.

In general, there are three common types of installation used to perform sterilization process on harvested oil palm fruits. One method involves sterilizing the fruits in horizontally placed cylindrical vessels fitted with opening door on both ends. Such horizontally placed sterilizers are served with rails by which cages loaded with palm fruits are pushed into interior of the cylindrical vessels. Upon closing the doors, pressurized steam is injected into the vessels and cooking process begins.

Such horizontal sterilizers usually have good sterilization effect due to the fact that charged fruits are spread over the horizontal cages and so individual fruits become fairly and evenly exposed to the injected steam. However, such kind of sterilizers has one major disadvantage in that the associated components e.g. the rails and cages are bulky and they take up substantial amount of usable space within the treatment vessels. Therefore, economy of scale is lacking in this kind of sterilizers.

Another disadvantage associated with horizontal sterilizers is that because the cages used for loading fruits are made of iron, they are easily susceptible to rusts and corrosion under the wet and humid conditions within sterilizer vessels. As such, palm fruits under treatment can easily become contaminated and then affect quality of the oil being extracted later on.

Another method of sterilizing oil palm fruits is by using vertically installed vessels for cooking the charged in fruits. Such vertical sterilizers have benefit of doing away with the iron cages in admitting fruits into treatment vessel. Harvested fruits are admitted directly into vertical vessel through opening door called inlet that is generally located at the top of a vessel. However, such kind of vertical sterilizers also has an obvious disadvantage in that when a treatment vessel is fully charged with fruits, the fruits that are charged in first and located at bottom of the vessel become badly compressed and have less accessibility to the injected steam. As a result, the overall sterilization effect would become less desirable.

Yet another method to sterilize harvested oil palm fruits is by using a kind of sterilizers that is tilt-able between horizontal and vertical position. Accordingly, cylindrical vessel of a tilt-able sterilizer can assume different inclinations between the vertical and horizontal position according to needs. For charging fruits into the vessel, the sterilizer can be tilted to vertical position or fairly inclined position such that incoming fruits, usually from overhead conveying belt, can be loaded directly into the sterilizer via a top opening door.

When loading is completed, the same tilt-able sterilizer can be tilted to rather flat or horizontal position so as to achieve better cooking or sterilization effect for the admitted fruits. Upon completion of sterilization, the cylindrical vessel can again be erected to another position of convenience, generally quite upright position, for discharging the treated fruits through an outlet opening door located at bottom of the vessel into some kind of collection facility. Due to advantages over more traditional installations, tilt-able sterilizers have now become a popular option for mill operators for sterilizing freshly harvested oil palm fruits. Full details for a particular embodiment of tilt-able sterilizer can be found in Malaysian Patent No. MY-139899-A entitled "A sterilizer for treatment of oil palm and similar fruit bunches". Similar description of said patent ¹ is also available in PCT database which is published as PCT/MY2007/000055 accompanied with full international search report.

The unique feature of said kind of tilt-able sterilizers is that its cylindrical vessel containing palm fruits to be sterilized can be tilted to any inclinations between horizontal and vertical position during a treatment cycle. When the vessel tilts to another position, the steam inlet for receiving pressurized steam into the vessel accordingly changes to another position. That is to say the steam inlet changes to different position during different stage of the sterilization process, i.e. with the vessel in fairly vertical position for charging in the fruits, with the vessel in quite horizontal position for cooking of the charged fruits and with the vessel at highly inclined position for discharging of sterilized fruits.

To cope with such situation in which the steam inlet is subject to assume different positions during a sterilization process, some mill operators opt to provide pressurized steam into sterilizer vessels by using flexible plastic-based hoses which are connected to external steam sources. It is a reasonable attempt provided that the flexible hoses can endure the fairly high operative parameters of pressure and temperature associated with the treatment steam, which generally are in the order 3.5 Bar (or 55 Psi quoted in the more commonly used local units) and 180 degrees C. If durability of such hoses is low, they need to be replaced quite regularly to ensure operation safety. As such, maintenance costs would escalate.

Alternatively, external pipeline made of metallic material like cast iron can be used to provide pressurized steam into vessel of tilt-able sterilizer via the steam opening. As metallic pipeline is rigid as compared to the flexible hoses, the challenge is how to keep such rigid external pipeline closely follow the movement of steam opening of a constantly tilting or moving vessel. Mechanically speaking, when a sterilizer vessel tilts or moves, particularly during take-off or stop-over for a new operation, its heavy body would impart sudden jerks or pressure on connecting joints between the metallic steam pipe and steam opening on the vessel body.

With such rough conditions, the above-mentioned connecting joints can become fairly vulnerable to cracks and damages due to the fact both the external steam pipe and steam opening on the vessel body are made of rigid metallic materials. Therefore, mill operators need to endure increased risks of steam leakage and even eruptions of said connecting joints in midst of sterilization process. As a result, such kind of installation requires further improvements in order to get rid of the above disadvantages.

As such, it is a primary object of the present invention to provide an installation for treatment of harvested oil palm fruits comprising a steam supply unit and a sterilizer unit such that pressurized steam can be provided into vessel of the sterilizer from one fixed location even when said vessel could be moved or tilted to different positions at different stages of the sterilization process.

It is an object of the present invention to provide an installation for treatment of harvested oil palm fruits comprising a steam supply unit and a sterilizer unit wherein both units are connected and can be installed, operated and functioned as a single entity for sterilization of harvested oil palm fruits.

It is another object of the present invention to provide an installation for treatment of harvested oil palm fruits comprising a steam supply unit and a sterilizer unit in which an external steam source can be conveniently connected to the steam supply unit at a fixed location. Said steam supply unit then injects steam into vessel of the sterilizer.

It is yet another object of the present invention to provide an installation for treatment of harvested oil palm fruits that ca easily be adapted to work with existing sterilizers with minimum physical modifications. Other objects and advantages of the present invention will become more apparent when it is described with the aid of the preferred embodiments as hereinafter mentioned.

Summary of Invention

The present invention concerns an installation for treatment of harvested oil palm fruits comprising a sterilizer unit and a steam supply unit working in combination.

Said sterilizer unit comprises a vessel in the shape of cylinder, said vessel having an inlet for admitting fruits into the vessel, at least one steam opening for receiving pressurized steam from external source for treatment of the admitted fruits, an outlet for dispensing treated fruits, a pivot along the vessel body capable to anchor to a fixed structure about which said sterilizer unit is tilt-able.

Said steam supply unit comprises a shaft having first end fixedly mounted to the pivot of said sterilizer unit and second end securely connected to a pipeline, said pipeline being provided with means to receive pressurized steam from an external source, a housing in the form of open-ended cylindrical structure having internal diameter marginally larger than said pipeline and an external sleeve means, said housing being disposed in a manner encasing longitudinally terminal portion of the pipeline and extending beyond end of the pipeline thereof, a flange being provided adjacent to said housing and held in stationary position by holding means rigidly mounted to part of the pivot whereby the sleeve means of said housing works cooperatively with the flange for retaining the housing on the pipeline, gland packing being provided in gap found between the pipeline and the housing to facilitate said housing being rotatable about the pipeline, and an elbow in the form of curved hollow conduit being connected to free end of said housing to receive pressurized steam from the external source.

When the foregoing sterilizer unit and steam supply unit work in combination during a sterilization process for treatment of harvested oil pal fruits, said elbow is capable to supply pressurized steam to the sterilizer vessel from one particular location irrespective of where the sterilizer unit has been tilted to because of the combined rotational effects of said housing and said elbow of the steam unit.

Specific Example

The invention will now be described by way of example and with reference to the accompanying drawings in which:

Fig. 1 shows perspective front side view of the preferred embodiment according to the present invention in which the sterilizer vessel is disposed in horizontal position.

Fig. 2 shows perspective view of major components of the steam supply unit according to the preferred embodiment.

Fig. 3 shows perspective view of the steam supply unit being connected to the sterilizer unit at the pivot of the preferred embodiment.

Fig. 4 shows cross-sectional view of major components of the steam supply unit and sterilizer unit working in combination with one another during sterilization process.

Fig. 5 shows perspective view of the housing of steam supply unit and its auxiliary features according to the preferred embodiment. Fig. 6 shows perspective view of the flange of steam supply unit according to the preferred embodiment.

With reference to the attached drawings, the inventive installation for treatment of harvested oil palm fruits according to the present invention comprises two units namely sterilizer unit and steam supply unit working in combination with one another to produce the desired effects as mentioned in the foregoing background.

As shown in Fig 1, the sterilizer unit includes a vessel 10 in the shape of a cylinder into which freshly harvested palm fruits are charged in for treatment using pressurized steam of pre-determined pressure and temperature, which normally is associated with high operative parameters in the order of pressure 3.5 Bar and temperature 180 degrees Centigrade. Said sterilizer vessel has an inlet 12 for charging in fruits, a steam opening 16a for receiving pressurized steam supplied from an external source, and an outlet 14 for dispensing treated palm fruits after completion of the sterilization process.

According to Fig. 1, it is obvious that there can be a number of steam openings 16a, 16b, 16c constructed in various locations on the vessel body for admission of pressurized steam for purpose that treatment steam can reach out more evenly to palm fruits within the vessel. As shown, said steam openings are linked up to a plurality of main and sub steam pipes 18a, 18b, 18c made of suitable material and construction.

The sterilizer unit further includes a pivot 20 along the vessel body capable to anchor to a fixed structure 24, about which said sterilizer vessel can be tilted by a tilting means 22 such as a hydraulic piston of suitable manufacture to different orientations between horizontal and vertical position for purpose of more effective treatment of the admitted fruits. In palm oil mills, freshly harvested fruits are sent by conveyor belts, not shown, to the site of sterilization as soon as possible. Normally, palm fruits are carried by overhead conveyor belts and charged directly into fairly upright standing sterilizers. According to the present invention, therefore, the sterilizer vessel is tilted to highly inclined position with the inlet on top to facilitate charging in of palm fruits into empty vessel.

Technical details about operation of tilt-able sterilizer have been extensively discussed in Malaysian Patent No. MY-139899-A entitled "A sterilizer for treatment of oil palm and similar fruit bunches" with regard to the most effective way for sterilizing harvested palm fruits. In general, the sterilizer vessel is tilted to substantially horizontal or flat position during steam treatment or cooking by the admitted pressurized steam. After cooking by pressurized steam, the sterilizer vessel is again resumed to fairly upright position in order that treated fruits can be more easily discharged through the outlet located at bottom of the sterilizer vessel.

According to preferred embodiment of the present invention, the steam supply unit includes a solid shaft 28 having one of its ends fixedly mounted to the pivot 20 of said sterilizer unit as can be seen in Fig. 1 and Fig. 3. After the sterilizer unit has been anchored to a fixed structure 24, the pivot 20 becomes physically fixed and immovable, and accordingly the shaft 28 is also stationary with the whole installation at all time.

The other end of the shaft 28 is securely connected to a pipeline 30 as shown in Fig. 2 and Fig. 4. The pipeline is made of metallic material enclosed externally by conventional heat insulation stuff. Said pipeline 30 is provided with means 26 to receive pressurized hot steam from an external source, not shown in the attached drawings. Said steam supply unit further includes a housing 32 in the form of an open- ended cylindrical robust structure as shown in Fig. 6. Said housing 32 has substantially uniform cylindrical body with internal diameter marginally larger than the external diameter of the pipeline 30. Externally, said housing 32 has a sleeve means 34 at one end which has an enlarged external cross sectional area thereto, as shown in Fig. 6.

According to the present invention, said housing 32 is provided lengthwise longitudinally on one end of the pipeline 30, encasing terminal portion of the latter due to its internal diameter being larger than external diameter of the pipeline, as shown in Fig. 2 and Fig. 4. Free end of said housing extends beyond the free end of said pipeline. There is a circumferential free space or gap found between the pipeline 30 and the housing 32 when they are assembled together as just described. Such gap is pre-determined by design choice to enable said housing having sufficient leeway to rotate about the pipeline given that suitable lubrication material is injected there in-between which is to be described later.

According to Fig. 4, the other end of the pipeline 30 is securely connected to a rigid structure 36 which in turn is fixedly mounted onto the immovable shaft 28 as mentioned earlier. Said rigid structure 36 has an upright wall facing the passageway of said pipeline in order to deflect pressurized steam coming from the external source forward and towards the direction where tenninal portion of said pipeline 30 meets said housing 32 as discussed earlier.

As shown in Fig. 4, the steam supply unit further includes a flange 38 next to said housing 32. Said flange 38 includes a pair of retaining members 40, spaced apart but linked up together by three holding means 42 in the form of bolts of certain length and being tightened up thereto by nuts 44 as clearly shown in Fig.

5. The retaining members 40 have the configuration of metallic washer with round edges. One of the retaining members 40 is rigidly mounted to the shaft 28 via brackets 46 as shown in Fig. 2 and Fig. 4. As said shaft is fixedly mounted to the pivot 20 of said sterilizer unit, the entire flange 38 is also a stationary construction upon installation.

Upon installation as shown in Fig. 2 and Fig. 4, said flange 38 has its retaining members 40 disposed transversely across the housing 32. In such position, the sleeve means 34 of said housing 32 works cooperatively with retaining member 40 of said flange so that said housing is kept on the pipeline 30 and restrained from any linear movement.

As mentioned earlier, a gap is found circumferentially between the cylindrical housing 32 and the pipeline 30 which is encased therein due to marginal differences in the cross sectional areas between these two components. To ensure effective steam flow within the steam supply unit as shown in Fig. 4, such gap must be sealed to disallow any leakage of steam during a sterilization process.

To prevent steam escaping from the steam supply unit, the present invention uses gland packing technology as sealing procedure for closing up the gap found between the housing 32 and the pipeline 30. In this connection, a cover 50 is provided to the housing 32 as shown in Fig. 6 so as to facilitate introduction of grand packing 48 into the above-mentioned gap.

Said cover 50 has an inner stem 52 that is capable to receive the sealing material in packing rings, or the likes, wound tightly around its neck thereof and then inserted into the gap found between the cylindrical housing and pipeline. Henceforth, gland packing 48 is fitted over the encased pipeline 30 and compressed further externally by the cylindrical housing 32. It is obvious that gland packing technology is well known to a man skilled in the art for prevention of leakage of fluid such as water and steam, between rotating and turning parts. π

In the present embodiment as shown in Fig. 4, application of gland packing prevents leakage of steam during the sterilization process while still allowing said housing 32 to rotate smoothly and freely around said pipeline 30.

The preferred embodiment further includes an elbow 54 in the form of curved hollow conduit being connected to free end of the housing 32 as shown in Fig. 4, wherein pressurized steam from the external source can continue to travel on. Said elbow 54 is capable to rotate freely to different directions as the housing 32 rotates about the pipeline 30.

As shown in Fig. 4, there are arrow indicators showing direction of flow of the pressurized steam within the steam supply unit during a sterilization process. Ongoing pressurized steam always exerts pressure on the housing 32 and elbow 54 urging them to move forward. Therefore, the above-mentioned flange arrangement 38 which works cooperatively with sleeve means 34 of the housing has the obvious function to restrain said housing 32 from moving linearly forward but keep it on the pipeline 30 all the time.

As shown in Fig. 1 and Fig. 3, it is obvious that the elbow 54 is capable to supply pressurized steam to the sterilizer unit from a particular fixed location determined solely by the pivot 20 irrespective of where the sterilizer vessel would tilt to. To facilitate supply of pressurized steam to the sterilizer vessel 10, steam conducting pipeline of suitable material and length is connected to the elbow 54 to distribute pressurized steam to various steam openings 16a, 16b, 16c and equivalent located at different parts of the vessel. In the preferred embodiment as shown in Fig. 1, the sterilizer vessel has a main steam pipe 18 which branches out to smaller or sub steam pipes 18a, 18b, 18c for distribution of steam to various locations of the vessel in order to achieve maximum sterilizing treatment effects for the admitted fruits therein.

It is evident that in a sterilization cycle, when the tilting means 22 raises or lowers the sterilizer vessel 10 to different positions, the elbow 54 is being dragged along because of its connection to the main steam pipe. In this connection, the elbow is adapted to adjust its direction freely due to smooth rotational effects of the housing 32 around the pipeline 30 as described before. Such smooth rotational effects cut down on jerks or pressures that could arise to impart on any connecting joints found on the sterilizer unit when the vessel 10 changes position during sterilization process. After completion of a sterilization process, the vessel 10 is tilted to a fairly inclined position so that treated fruits can easily be discharged through the bottom outlet 14, collected and carried away by conveyor belts to the next station of concern in a palm oil mill.

While only one embodiment of the present invention has been shown and described, it will be clear that various modifications and changes could be made without departing from proposed scope of the invention as defined in the following claims.

Claims

Claims:

1. An installation for treatment of harvested oil palm fruits comprising a sterilizer unit and a steam supply unit working in combination; wherein said sterilizer unit comprises a vessel (10) in the shape of cylinder, said vessel having an inlet (12) for admitting fruits into the vessel, at least one steam opening (16a) for receiving pressurized steam from external source for treatment of the admitted fruits, an outlet (14) for dispensing treated fruits, a pivot (20) along the vessel body capable to anchor to a fixed structure (24) about which said sterilizer unit is tilt-able, and wherein said steam supply unit comprises a shaft (28) having first end fixedly mounted to the pivot (20) of said sterilizer unit and second end securely connected to a pipeline (30), said pipeline being provided with means (26) to receive pressurized steam from an external source, a housing (32) in the form of open-ended cylindrical structure having internal diameter marginally larger than said pipeline and an external sleeve means (34), said housing being disposed in a manner encasing longitudinally terminal portion of the pipeline and extending beyond end of the pipeline thereof, a flange (38) being provided adjacent to said housing (32) and held in stationary position by holding means (42) rigidly mounted to part of the pivot (20) whereby the sleeve means of said housing works cooperatively with the flange for retaining the housing on the pipeline, gland packing (48) being provided in gap found between the pipeline (30) and the housing (32) to facilitate said housing being rotatable about said pipeline, and an elbow (54) in the form of curved hollow conduit connected to free end of said housing to receive pressurized steam from the external source, such that during a sterilization process, said elbow is capable to supply pressurized steam to the sterilizer vessel from one particular location irrespective of where the sterilizer vessel has been tilted to because of the combined rotational effects of said housing and said elbow of the steam unit.

2. An installation for treatment of harvested oil palm fruits according to claim 1 wherein the elbow (54) connects to a main steam pipe (18) that branches out to a plurality of sub steam pipes (18a, 18b, 18c) to distribute steam to a number of steam openings (16a, 16b, 16c) located at different parts of said sterilizer vessel.

3. An installation for treatment of harvested oil palm fruits according to claim 1 wherein said housing (32) is provided with a cover (50) having an inner stem (52) such that grand packing (48) can be wound thereon and inserted into the gap found between the housing and pipeline.

4. An installation for treatment of harvested oil palm fruits according to claim 1 wherein said flange (38) includes a pair of retaining members (40), spaced apart but linked up together by holding means (42) in the form of bolts of certain length and being tightened up thereto by nuts (44).

5. An installation for treatment of harvested oil palm fruits according to claim 4 wherein said retaining members (40) are in the form washer and there are at least three holding means (42).

6. An installation for treatment of harvested oil palm fruits according to claim 4 wherein one retaining member (40) is rigidly mounted to the shaft (28) of said sterilizer unit via brackets (46).