WO2013154419A1

WO2013154419A1 - An apparatus for dry fractionation of oils and fats

Info

Publication number: WO2013154419A1
Application number: PCT/MY2013/000077
Authority: WO
Inventors: Seong WONG; Ping Sing YAP
Original assignee: Oiltek Sdn Bhd
Priority date: 2012-04-09
Filing date: 2013-04-09
Publication date: 2013-10-17
Also published as: MY156842A

Abstract

A crystallizer (100) for use in dry-fractionation of oils and fats is disclosed. The crystallizer (100) comprises a cooling chamber having a first compartment (11) and a second compartment (12) for crystallization of oils and fats, wherein the first compartment (11) is provided with at least one set of helically coiled heat exchanger element (16) while the second compartment (12) is provided with at least one set of a plurality of vertically elongated heat exchanger elements (17), wherein helically coiled heat exchanger element (16) and vertically elongated heat exchanger elements (17) can be connected either sequentially or in parallel. Such an arrangement of heat exchanger unit system (13) within the cooling chamber provides not only high specific surface area for heat transfer, and also substantially reduces energy consumption of the crystallizer (100).

Description

An Apparatus for Dry Fractionation of Oils and Fats

Field of Invention The present invention relates to an apparatus for dry fractionation of oils and fats, more particularly, relates to a hybrid crystallizer comprising a combination of helically coiled heat exchanger element and a plurality of vertically elongated heat exchanger elements for dry- fractionation of oils, fats and the like.

Background of the Invention

Organic solvent fractionation, emulsion fractionation, and dry fractionation are methods that have been widely- employed for separating a lipid material into fractions with different melting points. Among these fractionation methods, the dry fractionation method which generally involves the steps of crystallization of oils and fats and subsequently separation of crystallized oils and fats in a filtration equipment is rather preferred in the art. This is mainly because of its relatively low operational costs, and also the sustainability and safety of the process. Unlike the organic solvent and the emulsion fractionation methods, the dry fractionation method does not involve the use of highly inflammable solvent such as acetone or hexane, production of polluting effluents or any post- refining processes. It is therefore the primary object of the present invention to alleviate the aforementioned limitations by providing a crystallizer for use in dry fractionation of oils and fats comprises a combination of helically coiled heat exchangers and vertically elongated tubular heat exchangers which arranged in such way that it is able to provide a well-controlled cooling process and with excellent heat transfer efficiency.

It is yet another object of the present invention to provide a crystallizer having a simple and yet economical structural design that effectively avoids settling of crystal slurries at the bottom and/or surface of the heat exchangers in the crystallizer, and thereby shortens the crystallization period of the oils and fats in the crystallizer.

It is yet another object of the present invention to provide a crystallizer which is able to produce crystal slurries with relatively high solid content at substantially low operational costs. Other objects of this invention will become apparent on the reading of this entire disclosure.

Summary of the Invention

In one aspect of the present invention, disclosed a crystallizer comprises a cooling chamber having a first compartment and a second compartment for crystallization of oils and fats, wherein the first compartment is provided with at least one set of helically coiled heat exchanger element while the second compartment is provided with at least one set of plurality of vertically elongated heat exchanger elements, and vice versa. Preferably the set of plurality of vertically elongated heat exchanger elements is in fluid communication with one another by means of a fluid distribution pipe and the fluid distribution pipe is connected to an inlet and outlet for circulating the cooling medium. Each of the vertically elongated heat exchanger elements comprises at least one vertical pipe having its ends supported in between a top header and a bottom header. Preferably each of the vertically elongated heat exchanger elements provided in a single-pass, 2-pass, or multiple- pass configurations. Preferably each of the vertically elongated heat exchanger elements placed at a tilted angle away from radial direction to provide a smooth circulation flow hence enhance the heat transfer. Brief Description of the Drawings

Other objects, features, and advantages of the invention will be apparent from the following description when read with reference to the accompanying drawings. In the drawings, wherein like reference numerals denote corresponding parts throughout the several views:

Figure 1 is a cross-sectional view of a crystallizer for dry-fractionation of oils and fats with . accordance to a preferred embodiment of the present invention;

Figure 2 illustrates a vertically elongated heat exchanger element of the crystallizer with accordance to a preferred embodiment of the present invention; and Figure 3 is a top sectional -view of the vertically elongated heat exchanger elements of the crystallizer as depicted in Figure 2. Detailed Description of the Preferred Embodiments

The present invention will now be described in detail with reference to the accompanying drawings. Referring to Figure 1, a crystallizer (100) for use in dry fractionation of oils, fats and related products is illustrated. The crystallizer (100) comprises a cooling chamber (10) provided with at least two communicating compartments, namely a first compartment (11) and a second compartment (12). These communicating compartments (11, 12) respectively define a first cooling segment and a second cooling segment for crystallization of oils and fats. A heat exchanging unit system (13) is provided to the crystallizer (100) of the present invention. The heat exchanging unit system (13) is preferably positioned adjacent to an internal wall surface (10a) of the cooling chamber (10). The crystallizer (100) may further includes a temperature measurement device (not shown) , a controlling system (not shown) for manipulating temperature of the crystallizer (100) and an agitator (not shown).- to prevent crystal slurries from settling at the bottom of the cooling chamber (10) . At least one inlet (14a, 15a) for introduction of cooling medium into each cooling segment of the compartments (11, 12) of the cooling chamber (10) and at least one outlet (14b, 15b) for discharging the cooling medium out of each cooling segment of the compartments (11, 12) of the cooling chamber (10) are also provided. In the prefer embodiment of the present invention, the communicating compartments (11, 12) are arranged in sequentially having the first compartment (11) positioned on top of the second- compartment (12) .

The heat exchanging unit system (13) with accordance to the preferred embodiment is formed by at least one set of helically coiled heat exchanger element (16) provided in either compartments (11, 12) of the cooling chamber (10) and at least one set of a plurality of vertically elongated heat exchanger elements (17) provided in the other compartment (11, 12) of the cooling chamber (10) . In the prefer embodiment of the present invention, the first compartment (11) is provided with the helically coiled heat exchanger element (16) and the second compartment (12) is provided with the plurality of vertically elongated heat exchanger elements (17). Understandably, such a particular arrangement of the helically coiled (16) and vertically elongated (17) heat exchanger elements within the cooling chamber (10) is to address the problem of agglomeration and/or sedimentation of crystal slurries on the coil surface of the heat exchanger elements (16, 17), and thereby improving the overall specific heat transfer of the crystallization, rendering the crystallization time be substantially shortened. It should be understood that the helically coiled heat exchanger element (16) may be in fluid communication with the vertically elongated heat exchanger elements (17), and configured to allow the cooling medium such as water to flow from the vertically elongated heat exchanger elements (17) to the helically coiled heat exchanger element (16) or vice versa, and thus circulating there between. Alternatively, the heat exchanger elements (16, 17) provided in the first (11) and the second (12) compartments of the cooling chamber (10) may not be in fluid communication, and the cooling medium is separately circulating within the helically coiled heat exchanger element (16) and the plurality of vertically elongated heat exchanger elements (17) in a parallel manner. In accordance, to a preferred embodiment, at least one pumping means"^'- (not shown) may be connected to the helically coiled (16) and the vertically elongated (17) heat exchanger elements to enhance the circulation of the cooling medium there within. By having high circulation rate of the cooling medium within these heat exchanger elements (16, 17), temperature difference between the first (11) and the second (12) compartments can be substantially reduced, and which in turns would contribute to. the production of uniform crystal slurries with high solid content.

In accordance to this illustrated embodiment, the helically coiled heat exchanger element (16) provided at the first compartment (11) of the cooling chamber (10) includes a supporting channel (20) which is vertically extended from the top to the bottom of the heat exchanger element (16) . The supporting channel as known in the art generally contribute to formation of dead zones due to limited circulation and agitation, and as a result of which, crystal slurries tend to accumulate and settle thereon and thus make the crystallization process inefficient. Accordingly, in order to prevent formation of such dead zones, the supporting channel (20) is provided with a plurality of openings (not shown) , and which is preferably structured to enable unlimited agitation and circulation.

Referring back to Figure 1, the plurality of vertically elongated heat exchanger elements (17) is preferably provided in the second compartment (12) of the cooling chamber (10) with accordance in fluid communications with one another by means of the fluid distribution pipe (30), which provided at the upper part and the bottom part of the second compartment (12) of the cooling chamber (10). The bottom fluid distribution pipes (30a) which positioned at the bottom part of the second compartment (12) of the cooling chamber (10) having one end includes at least one feed inlet (14a) connected to a cooling medium supplying unit (not shown) and at least one outlet (14b) at the other end configured for withdrawal of the cooling medium out of the heat exchanger elements (17) after circulating the cooling medium through the plurality of heat exchanger elements (17) and top distribution pipe (30b).

The helically coiled heat exchanger element (16) is also provided with at least one inlet (15a) connected at the bottom of the heat exchanger element (16) and at least one outlet (15b) connected at the top of the heat exchanger element (16) . The inlet (15a) of the helically coiled heat exchanger element (16.). can be either connected to the outlet (14b) of the vertically elongated heat exchanger element (17) or to the cooling medium supplying unit. Each vertically elongated heat exchanger element (17), as shown in Figure 2, preferably comprises at least one vertical pipe (50) which is vertically placed and having its ends supported in between a top header (45a) and a bottom^■ header (45b) respectively which allows a more uniform flow of cooling medium within the vertically elongated heat exchanger elements (17). In a preferred embodiment, each vertically elongated heat exchanger element (17) comprises four vertical pipes (50) placed in between the top header (45a) and the bottom header (45b). Each top (45a) and bottom (45b) header is further provided with a connecting member (40) and connected to the fluid distribution pipes (30). Preferably, the connecting member (40) has a length ranging from approximately 150mm to 250mm. The connecting member (40) has an orifice (30c) with predetermined size that provides fluid communication between the distribution pipe (30) and the heat exchanger elements (17). This construction provides not only an optimum surface area for efficient heat transfer, and also assists to permit a distributed flow of cooling medium within these vertically elongated heat exchanger elements (17).

Further to the preferred embodiment, and as be readily seen in Figure 3, a pair of splitters (55) is provided at the predetermined locations of the distribution pipe (30) of the vertically elongated heat exchanger elements (17) to provide the heat exchanger elements (17) in a 2-pass configuration. It should be noted that there is no intention to restrict the vertically elongated heat exchanger elements (17) with such a 2-pass configuration. However, those heat exchanger elements (17) that are constructed with a single pass or multiple passes may be employed in the crystallizer (100) of the present invention. Figure 3 shows a top view of the vertically elongated heat exchanger elements (17) of the present invention, wherein each heat exchanger element (17) is placed at a tilted angle away from radial direction which provides a smooth circulation flow hence enhance the heat transfer.

As will be readily apparent to those skilled in the art, the present invention may easily be produced in other specific forms without departing from its essential characteristics. The present embodiments is, therefore, to be considered as merely illustrative and not restrictive, the scope of the invention being indicated by the claims rather than the foregoing description, and all changes which come . within therefore intended to be embraced therein.

Claims

1. A crystallizer (100) for use in dry-fractionation of oils and, fats, comprising:

a cooling chamber (10) having at least two communication compartments, namely a first compartment (11) and a second compartment (12) for crystallization of oils and fats, and a heat exchanging unit system (13) provided to said crystallizer (100) which positioned within said cooling chamber (10), wherein said heat exchanging unit system (13) comprises at least one set of helically coiled heat exchanger element (16) having at least one inlet (15a) and one outlet (15b) provided in one compartment (11, 12) for circulating a cooling medium to said heat exchanger element (16) and at least one set of a plurality of vertically elongated heat exchanger elements (17) having at least one inlet (14a) and one outlet (14b) provided in the other compartment (11, 12) for circulating a cooling medium to said heat exchanger elements (17) to perform said dry-fractionation process.

2. The crystallizer (100) as claimed in claim 1, wherein said outlet (14b) of said vertically elongated heat exchanger element (17) is connected to said inlet (15a) of said helically coiled heat exchanger elements (16) when said heat exchanger elements (16, 17) ..are arranged in series.

3. The crystallizer (100) as claimed in claim 1, wherein said crystallizer (100) further comprises a temperature measurement device and a controlling system for manipulating temperature of said crystallizer (100) .

4. The crystallizer (100) as claimed in claim 3, wherein said crystallizer (100) further comprises an agitator to prevent crystal slurries from settling at the bottom of said cooling chamber (10) .

5. The crystallizer (100) as claimed in claim 1, wherein said heat exchanger elements (16, 17) may be connected to at least one pumping : means to enhance circulation of cooling medium therein.

6. The crystallizer. (100) as claimed in claim 1, wherein said set of helically coiled heat exchanger element (16) includes a supporting channel (20) which is vertically extended from the top to the bottom of said heat exchanger element (16), said supporting channel (20) includes a plurality of openings to avoid formation of dead zones between the., supporting channel (20) and the helically coiled heat exchanger element (16) .

7. The crystallizer (100) as claimed in claim 1, wherein said set of plurality of vertically elongated heat exchanger elements (17) is in fluid communication with one another by means of a fluid distribution pipe (30) and said fluid distribution pipe (30) is connected to said inlet (14a) and outlet (14b) for circulating said cooling medium.

8. The crystallizer (100) as claimed in claim 1, wherein each of said vertically elongated heat exchanger elements (17) comprises at least one vertical pipe (50) having its ends supported in between a top header (45a) and a bottom header (45b) .

9. The crystallizer (100) as claimed in claim 8, wherein said vertically elongated heat exchanger elements (17) preferably comprises four vertical pipes arranged in parallel manner in between said top header (45a) and bottom header (45b) .

10. The crystallizer (100) as claimed in claim 8, wherein each of said top header (45a) and bottom header (45b) is further provided with a connecting member (40) and connected to said fluid distribution pipe (30) via an orifice (30c) .

11. The crystallizer (100) as claimed in claim 1, wherein each of said vertically elongated heat exchanger elements (17) may be provided in a single-pass, 2-pass, or multiple-pass configurations.

12. The crystallizer (100) as claimed in claim 11, wherein each of said vertically elongated heat exchanger elements (17) is placed at a tilted angle away from radial direction to provide a smooth circulation flow hence enhance the heat transfer.