An Improved Sterilizer

Technical Field

The invention relates to a sterilizer having application for discharging inflowable materials from sterilization containers, more particularly for discharging sterilized palm materials from containers after sterilization process for the production of palm oil.

Background Art

In palm oil production industry, raw fruit bearing bunches are subject to sterilization process which is normally conducted in standard metal containers. Such containers are generally in the shape of cylindrical vessel having an inlet means located at one end for receiving palm bunches and an outlet means located on the opposite end for discharging sterilized bunches. In between the inlet means, outlet means and the side walls of the sterilization containers, there is the internal chamber into which pressurized steam is injected to carry out the relevant sterilization process. In a typical sterilization process, the inlet means and outlet means are both closed to enable the pressurized steam to act on the palm bunches under control temperature and pressure for a limited period of time.

Conventional sterilization containers measure approximately 6 meters in length and about 1 to 2 meters in diameters depending on the production capacity of the palm oil mills concerned. In practice, it is common to find sterilization containers being installed in vertical or upright position, having the inlet means on top and the outlet means at the bottom. When mounted in this position, a sterilization container is ready to receive palm bunches through the inlet means located on top and to discharge the sterilized palm bunches through the outlet means located at the bottom end of the container upon completion of a sterilization cycle.

One common problem associated with sterilization container installed in vertical or upright position is that after a sterilization process, it is difficult to discharge the sterilized bunches through the outlet. Sterilized palm bunches would some how get stuck near to the vicinity of the outlet exit. Therefore, operators in the industry have problems in retrieving the sterilized bunches. The main cause for this problem is that sterilized palm bunches proximal to the outlet are constantly being compressed by palm bunches located higher up the same axis. Under such situation, the sterilized palm bunches located at the bottom segment of the container would become critically compressed and find it difficult to move out of the outlet because they are not flow-able materials. This effect would become worst for operators dealing with bigger containers and thus resulting in total blockage of sterilized bunches at the exit point of the outlet, a situation generally referred to as bridging effect in the industry.

The above congestion or blockage problem associated with the discharge of sterilized palm bunches from upright containers is further compounded by the fact that ^" conventional containers are designed with constricted or "bottle-neck" outlets wherein escape passage to the exterior is smaller than the cross-sectional area of the internal chamber concerned. Such narrow escape passage in the container would contribute - further to the congestion problem during the discharge of sterilized palm bunches from sterilization container.

To overcome the above problem in discharging sterilized palm bunches from sterilization container, several methods have been utilized. One method is to use a solid plunger inserted from the inlet end into the internal chamber thereto in an effort to clear off the congestion of sterilized palm bunches at the outlet end. Another method involves the use of special tools with which to pick out the congested palm pieces from the exit point of the outlet concerned. As the outlet is generally located at the bottommost of a sterilization container, it becomes a difficult and awkward job for operators to remove such pieces of palm bunches stuck at the exit point of the outlet. Anyway, it is an enormous job especially if it

involves a full load of palm bunches to be removed. Such job would incur a great deal of labor which becomes very detrimental to the operability and productivity of the conventional apparatus.

In addition, the workers doing the picking job also need to be very skillful so as not to cause damage to the sterilized palm fruits which are fairly fragile. If the fruits are damaged, the quality of the final oil products made out of sterilized palm bunches would be affected.

It is therefore the intention of the present invention to provide a device for discharging sterilized palm bunches out of sterilization container, which is fully mechanized, simple to operate and involves minimum labor force. As a result, the total operation time and labor cost for discharging the sterilized palm bunches from sterilization container will be greatly reduced. Accordingly, the production cost for the industry will become more competitive.

The main object of the present invention is that when discharging sterilized palm bunches, the sterilization container concerned is freed of congestion problem at the exit outlet. Sterilized bunches shall be discharged smoothly and orderly out of the container concerned.

In view of the above advantages, the sterilization process would only require fairly limited labor force to standby as the discharging process is done essentially by mechanical means. Therefore, the invention helps to cut down labor costs and increase productivity.

Regardless of whether a sterilization container is mounted in an upright or inclined position, the present invention has a further object in that full discharge of the sterilized palm bunches from sterilization container is possible without encountering any problem of palm bunches being stuck at some point along the escape passage towards the outlet.

It is also an object of the present invention to provide a discharging device which requires limited maintenance and involves little skilled manpower to operate, and hence it is economical to use the apparatus.

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 invention relates to an improved device for discharging sterilized palm materials from a sterilization container having all round side walls, an inlet for receiving materials and an outlet for discharging sterilized materials, which collectively define an internal chamber therein, the improvement comprising a support frame and a movable arm connected to the support frame.

The support frame is fixedly mounted on the exterior of the side wall of said container. The movable arm is connected to the support frame and extended through the side wall of said container into the internal chamber therein. The movable arm is movable between a retracted position and an operative position in a direction towards the outlet to force sterilized materials out from the internal chamber.

Specific Example The above features of the present invention will become apparent with reference to the following description and drawings, wherein:

Fig. 1 shows a side view of the preferred embodiment according to the present invention in an operative position.

Fig. 2 shows a side view of the preferred embodiment according to the present

invention in a retracted position.

Fig. 3 shows the top cross-sectional ^" view of the preferred embodiment according to Fig. 1.

Fig. 4 shows the top cross-sectional view of the preferred embodiment according to Fig. 2.

Fig. 5 shows a view of the attachment means of the support frame according to the preferred embodiment.

Fig. 6 shows the enlarged cross-sectional view within the dotted circle in Fig. 1 wherein the components are partly dismantled.

Fig. 7 shows the enlarged cross-sectional view within the dotted circle in Fig. 1 wherein the components are fully assembled.

Fig. 8 shows a perspective view of the strainer within the internal chamber of the sterilization container according to the preferred embodiment.

Referring to the drawings, Fig. 1 shows the preferred embodiment according to the present invention used for sterilization of oil palm fruit bunch.es in the palm oil production process. There is a sterilization container in the form of a cylindrical container 10 installed in an upright position having all round side walls, an inlet 12 for receiving relevant palm materials and an outlet 14 for discharging sterilized palm materials, which collectively define an internal chamber 101 therein.

The external body of said sterilization container 10 is installed onto a rigid mechanical structure 24 which is raised above the ground level by support beams 241 as shown. The installation of said sterilization container is such that the inlet

end 12 thereof is positioned on top and the outlet end 14 thereof is positioned at the bottom so that after a sterilization process, sterilized palm materials can be conveniently discharged into some kind of collection hopper (not shown) located below and be carried away by conveyor belts to another station to continue with the palm oil production process.

Typically, a conventional sterilization container measures approximately 6 meters in length and about 1 - 2 meters in diameter and is manufactured of robust metallic material. The inlet 12 includes an inlet gate 121 operated hydraulically by an inlet lock 122 into close or open position according to requirement. Likewise, the outlet 14 includes an outlet gate 141 operated hydraulically by an outlet lock 142 into close or open position according to requirement. ^"

The sterilization container 10 includes a plurality of steam inlets 16 provided through the side walls thereof in spaced positions, which inject pressurized steam into the internal chamber therein during a sterilization cycle. The sterilization container further includes a plurality of condensate outlets 18 provided through the side walls, proximal to the outlet 14 end near the bottom of the container according to the present embodiment. The condensate outlets 18 have provisions thereto for draining off to the exterior any water condensate that has been formed within the internal chamber during the sterilization process.

According to the preferred embodiment of the present invention, the sterilization container 10 includes a support frame 26 on its exterior body as shown in Fig. 1 and Fig 2. The support frame is mounted externally onto the side walls of the container body as indicated in Fig. 3 and Fig. 4. Said support frame 26 comprises two leg members 261 and 262, which extend upwardly to join up by cross beams between them forming a connection member 263 which is raised above the surface of the container body as shown in Fig. 5. The leg members 261, 262 of the support frame 26 have on their remote end respective mechanical lugs 266, 267 to enable the frame structure to be firmly affixed onto the side wall

of the container body by bolts and nuts.

On the raised end of the support frame 26, the connection member 263 includes a plurality of transversely disposed mechanical locking means 264 and 265 adapted to receive and lock in elongated structures of pre-determined dimension provided thereto as shown in Fig. 3, Fig. 4 and Fig. 5. An example of such elongated structures is a pneumatically powered hydraulic cylinder which is commonly available in the market.

As shown in the Fig. 3 and Fig. 4, the hydraulic cylinder 28 is firmly connected to the support frame 26 via the connection member 263 thereof in a longitudinal manner directing towards the surface of the container body. The hydraulic cylinder includes a stationary bore section 281 which is mechanically connected to the connection member 263 via locking means 264 and 265. Said hydraulic cylinder 28 further includes a stroke section 282 which is movable by pneumatic system.

The bore section 281 and stroke section 282 of the hydraulic cylinder 28 are disposed length to length in a telescopic arrangement such that the bore section 281 is stationary and the stroke section 282 is capable to fit inside said stationary bore section when in retracted position. The pneumatic system which operates the hydraulic cylinder provides the drive force to achieve linear reciprocal movement of the stroke section 282 such that in a forward manner, the stroke section is extended from the bore section 281 and in a retracted manner, the stroke section 282 is drawn back into the bore section 281.

As mentioned earlier, the technology concerning operation of hydraulic cylinder is known in the prior art. However, it should be appreciated that the drive force used to extend and retract the linear motion of the stroke section may also take other forms such as the driving force generated by electrically operated drive motor whose rotational movement can be translated into linear motion. In the

present embodiment, control panel (not shown) is used to operate the pneumatic system so as to regulate the reciprocal movement of the stroke section 282 according to operative requirements of the present invention.

As shown in Fig. 3 and Fig. 4, a movable arm 284 in the form of a cylindrical shaft is connected lengthwise and longitudinally to the remote end of the stroke section 282 via a mechanical coupling 283. The mechanical coupling shall convert directly the linear motion of the stroke section 282 into linear motion of the movable arm 284. Therefore, the reciprocal motion of the stroke section 282 of the hydraulic cylinder causes the movable arm 284 to move linearly, between an extended position and retracted position. The movable arm is made of robust material which has physical properties to withstand the high operating temperatures of the sterilization container 10 within the internal chamber.

The movable arm 284 has its remote end extend into the internal chamber of the sterilization container 10 through an opening formed into the side wall of the container body. To facilitate the installation of the movable arm into the opening, a housing 30 is initially affixed into the opening as shown in Fig. 6. In the present embodiment, the housing 30 comprises a recessed portion 301, and an external lid structure 302 adapted to close fit- into said recessed portion from the exterior side of the container 10. Both the recessed portion 301 and lid structure 302 have coaxially arranged central bore adapted to receive and install the shaft body of the movable arm 284 in a longitudinal manner as shown in Fig. 6 and Fig. 7.

Within the housing 30, a packing of gland material which is capable to withstand high operating temperatures of the sterilization container is provided. When the lid structure 302 is fitted into the recessed portion 301 of said housing with bolts, the protrusions 303 as shown in Fig. 6 compress against the gland material forming an effective ring thereto about the shaft body of the movable arm 284, thus serving as an insulation layer against any leakage of steam and heat from the

internal chamber of the sterilization container 10.

The remote end of the movable arm 284 projects into the internal chamber of the sterilization container 10. The length of the movable arm is pre-determined sjuch as to be capable to reach out to and in the direction of the outlet 14 thereof. To achieve such installation of the movable arm, it is assumed that an ordinary technician should have the experience to adjust the position and orientation of both the opening and housing 30 so that the projected portion of the movable arm 284 inside the internal chamber of the sterilization container 10 is directed towards the outlet 14. It is evident that the movable arm 284 is extendable whenever necessary by connecting additional unit or units of arm of different length to the existing one.

As shown in Fig. 1 and Fig. 2, the movable arm 284 includes at its remote end a pusher 285 connected thereto by mechanical means. In the embodiment shown in the figures, the pusher is a metallic solid structure having a substantially flat base and an upper ridged portion, said pusher having front end directing towards the outlet 14. Said pusher 285 has substantially larger transverse cross-sectional area than the terminal of said pusher so as to effectively urge the sterilized palm materials forward and towards the direction of the outlet 14.

Within the internal chamber of the sterilization container 10 and at the lower department proximal to the outlet 14, there is provided a funnel-shaped strainer

32. The strainer includes an upper rim connected to the inner perimeter wall of the container as shown in Fig. 7. The point of connection between the circular edges of the rim and the inner wall thereto is lower than the opening in the container wall by which the movable arm 284 projects into the internal chamber. The strainer 32 includes substantially flat walls perforated with holes, said walls tapering from the rim downwardly to form a guide channel towards the outlet 14 of the container as shown in Fig. 8.

In a typical sterilization process, raw oil palm bunches are charged into the sterilization container 10 through the inlet 12 from conveyor belts carrying the palm bunches. When charging of the palm bunches into, the container is done, the inlet gate 121 is then closed. Via a remote control panel, (not shown), pressurized steam of pre-determined physical properties is injected into the internal chamber of the container through various steam inlets 16.

The steam supply is controlled either manually or by a sequence of digital controllers programmed to suit the type and quantity of the palm bunches to be sterilized in the sterilization container 10. The sterilizing or cooking time normally depends on the quantity and quality of the palm bunches to be processed, which usually ranges from ^" 1 to 1 Vz hours. When the sterilization process is considered as complete, the sterilized palm bunches are ready to be discharged through the outlet 14 located at the bottom end of the container.

Liquid water may be formed during the sterilization process due to vapor condensation of the injected steam, which then travels down to the strainer 32 and into the bottom section of the container through gravity. The water thus formed is then drained off by the condensate outlets 18 located at the bottommost of the vertically installed container.

The sterilized palm bunches within the internal chamber of the sterilization container 10 is then ready to be discharged by the following steps. The inlet gate

121 situated at the top end of the container is first opened and then followed by the opening of the outlet gate 141 located at the bottom end thereof. The opening of said gates is done through hydraulically controlled inlet lock ring 122 and outlet lock ring . 142 which are electrically connected to the remote panel mentioned earlier.

During a discharging process, sterilized palm bunches tend to slide down the side walls of the container into the strainer 32 thereto under the influence of gravity

and then towards the outlet 14. The sterilized palm bunches tend to queue up near the outlet causing a temporary congestion in trying to leave the exit thereof.

In order to clear off the above-mentioned congestion proximal to the outlet 14, the movable arm 284 is set into operation by actuating the hydraulic cylinder 28 through a remote control means (not shown). When the hydraulic cylinder is actuated, the stroke section 282 thereof moves in reciprocal motion providing the relevant drive force to operate the movable arm 284 in extended and retracted positions accordingly. When the movable arm is extended, it is in operative position urging the sterilized palm bunches immediately next to the pusher 285 to move on towards the direction of the outlet 14.

Because of the linear motion of the stroke section 282, the movable arm 284 moves in identical reciprocal manner in that it extends forward in an operative position to push via the pusher 285 sterilized palm bunches forward in the direction of the outlet 14 and it retracts backward to allow sterilized palm bunches located above to take over spaces pre-occupied by bunches that have been pushed forward. By repeated reciprocal extended and retracted actions of the movable arm 284, the sterilized palm bunches are urged forward until all of them are completely discharged from the container.

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 the spirit and scope of the invention as defined in the claims.