MXPA98001481A - Deodorization plant for gra acids - Google Patents

Abstract

A de-odorization plant for treating fatty oils comprises a container (1) connected to a vacuum source. In the vessel there is a distillation column filled with a structured packing material through which column the oil to be deodorized flows under the influence of gravity and fuses countercurrently with a deodorizing gas. In the container there is also a number of trays for the collection of the oil provided with drainage outlets in its lower part. The oil is treated with the deodorizing gas intermittently in these trays. The container is provided with an inlet (7) for the oil, and a connection (2) with a vacuum source in its upper part. At the bottom, there is an exit (9) for the oil

Description

"DEEPORIZATION PLANT FOR FATTY ACIDS" The present invention relates to a deodorization plant for fatty oils comprising a container connected to a vacuum source. When consumer products of different vegetable oils or animals are produced, deodorization is part of the refining process. During deodorization the oil is heated to a high temperature of 180 ° C to 275 ° C in order to expel volatile impurities and unwanted substances from the oil. These subtances have a lower boiling temperature than the different glycerides that make up the fatty oil. The deodorization is carried out under vacuum conditions, with an absolute pressure of 1 to 20 mbar, and the removal is facilitated by the addition of deodorizing gas to the oil. - The gas facilitates the removal of unwanted substances. In the market there are currently a large number of different deodorization plants, both for continuous flow through the plant and with intermittent or batch treatment of the oil. During continuous deodorization, the oil usually flows through a number of trays or containers that are vertically stacked in a circular hull manner. At the bottom of the trays or containers there are means for the addition of gas. Alternatively, the gas can be added using a medium with a siphon effect. The oil and gas are forced up an ejector tube towards the deflection plate and finely divided against it. The oil is added to the container at the top of the plants, and flows from a higher container to the next container. In order to control the flow through the packages, these are provided with sieve plates in such a way that the oil flows from an inlet in a certain place in the package to an outlet in another place. The retention time in the vessel is graded to a certain value, depending on the geometry of the flow channels. The time of change between different products is prolonged. When the deodorization is carried out in batches, all operations (distillation, thermal retention for bleaching) are usually carried out in the same vessel. This method of work makes possible the rapid changes between the different oil products, but the retention time is prolonged since it depends both on the effect of distillation and on the transmission of heat. The present invention offers a solution to the problem to quickly change the retention time for the different operations in the deodorization plant, but still makes possible the rapid change between the different oil products. A deodorization plant according to the invention comprises a vessel connected to a vacuum in which there is both a distillation column filled with the structured packing material through which column the oil to be deodorized is flowed under the influence of the gravity and is coupled with the deodorization gas against the current, as well as a number of trays for collecting the oil provided with drainage outlets in its lower parts, in whose trays the oil is treated in batches with the deodorizing gas. The container is provided, in its upper part, with an inlet for the oil and a connection with a source of vacuum and with an outlet for the oil in the lower part. The column, as mentioned, is filled with a structured packing material the object of which is to create an increased area of contact and an increased time for contact between the oil and the deodorizing gas. This packaging material can be obtained in the market and is used for many different purposes. The time to go through the column is usually 5 to 20 minutes. Due to the efficiency of the column, the desired deodorization (removal of volatile impurities) can also be carried out at lower temperatures, which decreases the formation of trans-fatty acids. The working pressure (vacuum) can be kept low, at less than 5 mbar and if desired also at less than 1 mbar. The efficient contact in the column also results in a lower demand for the amount of the deodorizing gas. Usually the column is placed in the upper part in the container, but if it is desirable one or more trays for a first intermittent treatment can certainly be placed above the column. If the distillation column is placed in the upper part of the vessel, the oil is suitably added thereto, heated to a desired elevated temperature. The retention time in the container can be selected from 20 to 75 minutes. Advanously, the trays are without inserts directing the flow, but are provided with means for supplying the deodorizing gas in the vicinity of the bottom of the tray. A connection for the deodorizing gas is placed in the lower part of the container near the outlet of the container. A deodorization plant according to the invention is preferably provided with tubes connecting the space above each tray, with the space under the column, which makes it possible to achieve a desired level of vacuum throughout the container. According to the invention, a heat exchanger can advanously be placed at the outlet from the vacuum vessel. This heat exchanger is divided into sections that are connected to each other by means of shut-off valves. In each section there are means for the supply of deodorizing gas. The preference sections are placed at different height making it possible for the oil to flow from section to section by gravity. The oil treated from the vacuum vessel enters the upper section. In each section there is also a tube through which the oil to be treated in the recipe is directed. This untreated oil is heated by the treated oil which is valuable for reasons of energy saving. The deodorization gas used in the heat exchanger is conducted into the space below the column and is used for deodorization purposes in the column as well. The deodorization plant according to the invention is further described with reference to the accompanying drawing. Figure 1 of which shows the plant as such, while Figure 2 shows schematically the manner in which the plant can be used in order to be able to effect a rapid change between the different oil products. Figure 3 shows a perspective drawing of the heat exchanger connected to the vacuum vessel. As can be seen in Figure 1, the deodorization plant comprises a container 1 that is provided with a connection to the vacuum source. In the upper part of the container, there is a distillation column 3 consisting of a structured packing material that completely fills the cross section of the container. In the lower part of the container, there are the lower parts or bottoms 4, 4 'which are provided with outlet openings 5, 5', in their lower part. Below the outlet there are closing valves 6, 6 '. These lower pieces or bottoms 4, 4 'and the circular walls of the container form trays in which the oil is collected. In the upper part of the container, there is a supply tube 7 for the oil product to be treated in the container. Above the column are the means 8 for distributing the added oil product above all the cross section of the container. At the bottom of the container there is also a tray formed by the bottom of the container with a new outlet through which the treated product is extracted. Outside the vacuum vessel, there is a tube 10 connecting the space below the bottom 4 'with the space under the column 3. Likewise the space between the bottoms 4 and' connects with the space under the column 3, through the tubes 10 and 11. Just above the bottoms 4, 4 ', there are inlet pipes 12, 12' for the deodorizing gas. An outlet tube 13 for this gas is also placed at the bottom of the tray. A plant of the kind shown can now be used in the following way. The oil to be treated in the deodorization plant is pretreated in a manner known per se, preheating, de-aerating and heating it with an additional air removal, at a deodorization temperature of 250 ° C to 260 ° C. After this heating, the oil is directed towards the deodorization plant through the pipe 7 and is distributed above the cross section of the column 3. The oil flows down through the column in the form of thin films that they are continuously transformed and divided again by the inert packing material. In the column, the oil film is fused countercurrently with the deodorizing gas. There is a pressure of 0.5 to 20 mbar in the container connected to a vacuum source via connection 2. The deodorizing gas usually consists of steam, but nitrogen gas or carbon dioxide can also be used.Volatile unwanted products are released from the oil during the influence of deodorization gas and vacuum. When the oil has passed through the column, it is collected in a first tray surrounded by the walls of the container, which is formed through the bottom 4. Near the bottom 4, there is a means 12 for the supply of the deodorizing gas. Within this tray, the main part of the gas is supplied whose gas after having passed the amount of oil collected, flows upwardly against the bottom of the column. The oil that has flowed through the column in a continuous manner is collected in the tray, which is limited by the bottom 4. In this, the oil is maintained for a desired period of time, while flowing through it by means of deodorization gas. During this treatment, a chemical effect is carried out in the oil as a consequence of the high temperature. Due to the fact that the gas flows all the time through the unwanted oil, the disintegration products are removed. After the desired retention time, the valve 6 is opened and the oil is transferred to the next tray formed by the bottom 4 'and the walls of the container. Also in this tray, the deodorizing gas is supplied through the medium 12 '. When the desired retention time has been obtained, the valve 6 'opens and the oil is collected at the bottom of the container. After an appropriate period of time it is conducted to move away through the outlet 9. The deodorizing gas is also added here by means 13. From the container 1, the treated oil is directed towards a thermal exchanger 14 where it is added the deodorization medium through the medium 15. In the heat exchanger there is also a "U" tube 16 through which the oil, which is subsequently to be treated in the container, is forced to flow. The untreated oil is heated by the deodorized oil leaving the container 1. The cooled treated oil leaves the heat exchanger through the outlet 17. The gas leaves the heat exchanger through the tube 18 which is connected to the tube 10. By means of this arrangement, the gas used for the deodorization in the heat exchanger is also used in the column 3. In the embodiment shown, the plant comprises a column and two trays for intermittent treatment.

Of course, within the limits of the invention it is possible to work with additional columns and a smaller or larger number of trays. As described above, trays for intermittent treatment are created by the bottoms and walls of the containers. There are no flow direction inserts in the trays, but the oil is only picked up until a desired volume has been obtained. The height of the liquid in each tray can be up to 50 to 60 centimeters. Figure 3 shows the heat exchanger 14 (economizer) in detail. It can be seen in the drawing that the heat exchanger is divided into three sections 14, 14 ', 14' 'which are connected. The oil enters the upper section 14 through a tube connected to the outlet 9. The deodorizing gas is added to each section by means (not shown in the drawing). The gas leaves the sections through the tubes connected to the tube 18. The oil to be heated is directed towards a "U" tube 16, the entrances and exits of which are shown near the bottom of each section. At the top of the section, there are visual glasses. As mentioned, the treated oil enters the upper section and leaves it after a desired retention time. Between the sections there are the closing valves 19, 19 'which make it possible to use all the sections in the heat exchanger in succession or to leave an empty section if it is desired to change between the oils of different kinds. The oil flows from section to section due to gravity and exits the heat exchanger through the outlet 17. The deodorization plant according to the invention has great advantages when it is desired to change from one oil product to another. Figure 2 is schematically described in the manner in which this change can be effected. The valves VI and V2 close the exit of the trays, while valve 3 closes the outlet of container 1. When most of the oil has been drained at the bottom of the container, the oil change is started. The oil supply to the column stops and the oil in the column drains into the upper tray. The oil that has been thermally treated in the lower tray is transferred to the lower part of the container by opening valve V2. The oil in the upper tray is then directed towards the lower tray by opening the valve VI. When the upper tray is emptied and the contents in the lower tray have been transferred to the bottom of the container 1, the oil change can be carried out and the new oil added to the column. The new oil is then collected in the upper tray while the lower tray is empty.

Claims (6)

R E I V I N D I C A C I O N E S:

1. The deodorization plant for treatment of fatty oils comprising a container connected to a vacuum source, characterized in that there is a distillation column (2) filled with a packing material structured in the container (1) through which the oil column which is going to be deodorized is flowed under the influence of gravity and merges with the countercurrent deodorization gas, as well as the number of trays for collecting the oil that are provided with drainage outlets in its lower parts, in whose trays the Oil is treated intermittently with the deodorizing gas, where the vessel is provided with an inlet (7) for the oil and a connection (2) with the vacuum source at its top, and with an outlet (9) for the oil in its lower part.

2. The deodorization plant according to claim 2, characterized in that the column (2) is placed above the trays in the container.

3. The deodorization plant according to claim 1-2, characterized in that the trays do not have flow direction inserts, but are provided with means (12, 12 ') for the addition of the deodorization gas to the oil near of the respective fund.

4. The confection deodorization plant with claims 1-3, characterized in that there are means (13) for the supply of the deodorization gas in the bottom tray in the lower part of the container near the outlet thereof.

5. The confectionery deodorization plant with claim 1-4, characterized in that the container is provided with the tubes (10, 11) that connect the spaces above each tray with the space under the column, which makes it possible to obtain a level of vacuum desired throughout the recpinte. The deodorization plant according to claim 1, characterized in that a heat exchanger 14 divided into sections is connected to the outlet 9 from the container, the sections of which are connected to one another by means of shut-off valves (19, 19 ') and that are provided with means for the supply of the deodorizing gas.