CN1314788C - Two stage device for removing solvent from food granular powder - Google Patents

Abstract

The present invention relates to a desolventizing system which comprises a first desolventizing device and a second desolventizing device, and each device has an inlet, an outlet and a solvent vapour outlet, wherein the inlet accepts a granule containing a solvent, and the outlet discharges a granule at least desolventized partially. A solvent catcher is connected between the outlet of the first desolventizing device and the inlet of the second desolventizing device by a first airlock. The granule entering the solvent catcher by the first airlock is conveyed to the inlet of the second desolventizing device. A second airlock is connected with the output of the second desolventizing device. The solvent catcher is provided with an output which is connected with a vacuum source. The evaporated solvents of the desolventizing devices can be drawn out by the solvent vapour outputs of the desolventizing devices.

Description

From the food particle powder, remove the two-stage equipment of solvent

Background of invention

Particle of many plants or seed product as corn, Sunflower Receptacle and soybean (typically referring to oleaginous seed), are rich in the vegetables oil composition.Usually, in certain stage that processes raw material this oil component is extracted.This is valuable commercial materials in aspects such as food, plastics for this oil.It is valuable equally that oil extracts the last solid matter in back, can be used as food of the mankind or animal and other purposes.

The step that begins in the course of processing is to make the granule materials that does not become thin slice or other type as the oleaginous seed product of raw material.This granule materials has been full of a large amount of original natural oil.Then this oil is extracted from these granule materials.

Some different from this granule materials, removing or the method for extract oil have been developed.Here the interested process of deoiling is called solvent extraction.A material grain is become than after the small-particle, these material are immersed in the hydrocarbon liquid solvent, as the petroleum-based solvent of normal hexane, heptane, isohexane or any similar solubilized oils.

After material is immersed in the solvent, solvent again with a material in oil form liquor.Separate with a material by the solution of some method then, adopt simple gravity drainage method usually oil-solvent.In the gravity drainage process, a sieve supports particulate matter, allows oil-solvent solution flow in the save oil pan by sieve.Use known technology with solvent and separating of oil then.Usually, solvent is recovered in this separating step, and can reuse in extraction process.

After oil-solvent solution flows out, also has solvent and a spot of oil of appreciable amount in the granule materials usually from granule materials.If this granule materials will be used as people's food or the feed of animal.By a lot of reasons, it is very important removing most solvent from this granule materials.At first, solvent may be poisonous, can prevent that anyone or any animal to consuming these process the finished product from damaging so remove to desolvate from granule materials.The second, no matter whether solvent is poisonous, and it all may cause atmospheric pollution, so prevent that as much as possible a large amount of solvents from entering air is very important.The 3rd, solvent is valuable, so be necessary solvent to be extracted from granule materials again and reuse in the extraction process of oil.

United States Patent (USP) the 5th, 630, disclosed in No. 911 (Kratochwill) take out oil-solvent at gravity drainage or with other method after, the equipment and the method for removing a large amount of residual solvents.The equipment of Kratochwill has used several inclination travelling belts that are loaded with granule materials on hot-plate in the container or space of a sealing.There is the granule materials of solvent soaking to heat to still residual, makes solvent evaporation.Then solvent vapour is removed from the space of sealing.Still have some oil to be retained in the granule materials, but it only account for the sub-fraction of total material.The application is with reference to the invention that combines Kratochwill.

A feature of Kratochwill equipment is that heat-processed is to carry out under the protein dispersibility index that is enough to reduce the high granule materials of protein content (protein dispersabity index) temperature (PDI).But for some treated oleaginous seed material, high PDI is preferred; For these materials, should adopt lower Heating temperature.

The invention summary

The inventor has developed a kind of removal solvent systems that can remove nearly all solvent from the plant thin slice that necessarily contains solvent or particle.This system comprises that first removes solvent device, and it has an acceptance to contain the inlet of solvent particles, the outlet that discharge is at least partly used except that the particle that desolvates, and a solvent vapour outlet.First removes solvent device heats particle, makes the liquid solvent evaporation.Almost can discharge from the solvent vapour outlet by the steam of the solvent-steam of all solvent compositions.

First airlock has an inlet that is connected with first outlet of removing solvent device, also has an outlet.First airlock removes part at least the particle desolvate and is sent to the outlet of first airlock from the inlet of first airlock, simultaneously the inlet that can keep first airlock to small part with export between pressure difference.

Solvent trap has a chamber, and entrance and exit protrudes upward from this chamber.The inlet of this trap is connected with the outlet of first airlock, is used for accepting particle and steam from first airlock.The outlet of this trap provides particle to second inlet of removing solvent device.Near the vertical place of trap, a vapor outlet port is preferably arranged so that be connected with vacuum source.

Second removes solvent device the particulate inlet of an acceptance from the solvent trap chamber, and discharge for one and finally remove the particulate outlet of desolvating, and a solvent vapour outlet, this device while heated particle.Second remove the inlet of solvent device and solvent vapour outlet preferably all be contained in the vapor outlet port that is higher than solvent trap the position, prevent that flowing into second from the steam that first airlock enters solvent trap removes solvent device.

Second airlock has an inlet that is connected with the second removal solvent device outlet, therefrom accepts the final grain flow that desolvates that removed.Second airlock also has an outlet, discharges the final grain flow that desolvates that removed by this outlet.

Be connected vacuum source in the solvent trap outlet and can remove in the solvent device second and produce vacuum, this vacuum is enough to make the liquid solvent stayed in the particle or the boiling point lowering of water, in order to avoid the PDI in the particle too reduces.In a scheme, vacuum is greatly about-7psig.

The accompanying drawing summary

Fig. 1 is a diagrammatic side views of removing the solvent systems major portion.

Fig. 2 is the skeleton diagram that forms the condenser/vacuum pump apparatus of vacuum preferably in some part of removing solvent systems.

Preferred embodiment is described

Fig. 1 has shown one embodiment of the invention, is a big chunk of the contained solvent of the vegetable particle material that is used for removing a certain amount of different shape (following use " thin slice " or " chip material " for convenient meter).This solvent is to add in the early stage step of processing, is used for extracting the oil in the thin slice.The present invention is particularly suitable for removing from the thin slice of rich in proteins and desolvates, and removing the temperature of desolvating should be low, for example is lower than 180 , so that make its protein keep high PDI.The solvent boiling point when pressure reduces that is fit to the present invention's use is lower than about 180 , and the mass density when gaseous state is higher than the air under the same temperature and pressure.The example of this kind solvent has hexane, isohexane and heptane.

Structure

The treatment stage that the present invention having used at least two, each stage comprises that is all removed a solvent device 10 or 11.Each removes the solvent that solvent device 10 or 11 can be removed high per-cent in the chip material that enters this device 10 or 11.Removal solvent device 10 and 11 in this preferred embodiment is structurally all described similar with Kratochwi11, but also can the more lower slightly dissimilar removal solvent device of service efficiency.Because the description of Kratochwill has been enough to illustrate the structure and the operation of removing solvent device 10 and 11, again 10 and 11 internal features that install are described in detail with regard to there is no need here.Each removes the inlet 15 or 38 and the outlet 16 or 39 of thin slice that solvent device 10 or 11 all has thin slice.Solvent-laden thin slice as soybean and so on oleaginous seed falls into inlet 15 or 38.

In device 10 or 11, all be that thin slice moves to thin slice outlet 16 or 39 from thin slice inlet 15 or 38 through a roundabout.In this shift motion, device 10 and 11 is all to thin slice heating, makes the most of solvent in the thin slice and the steam mixture of some aqueous vapor formation solvent-steam.When thin slice passes through device 10 or 11 respectively, from solvent outlet 13 or 41, extract solvent-vapour mixture out, just can almost completely remove the solvent that gasifies and to adopt from thin slice.At terminal point through each device 10 or 11 stroke, to remove solvent device 10 or 11 inlet 15 or the solvent that contained at 38 o'clock at each originally in the thin slice and be removed mostly, thin slice just falls by exporting 16 or 39.

Airlock or rotary valve 18,25 and 28 are the devices that are used for keeping partial vacuum in removing solvent device 10 and 11.One type airlock 18,25 or 28 has rotatable gate, and this gate is the spitting image of allowing thin slice enter the revolving door of corresponding outlet 18b, 25b, 28b from inlet 18a, 25a, 28a under action of gravity.For thin slice is transported to outlet from inlet, it also is suitable keeping pressure difference between inlet and the outlet simultaneously and using the airlock that has gate or flap.This structure makes and have certain pressure difference between 18b, the 25b of inlet 18a, the 25a of airlock, 28a and corresponding airlock, 28b.

Solvent trap 30 has from first removes the inlet 30a that accepts solvent-vapour and thin slice the solvent device 10 simultaneously.This solvent-vapour major part is come by airlock 18 leakages or only is to be come by the thin slice band.Mainly be solvent in solvent-vapour, having only a small amount of (about 5%) steam is water vapour.Solvent trap 30 has an outlet 30b, leads to second by this outlet thin slice and removes solvent device 11.The collecting chamber 31 of solvent trap 30 bottoms is collected from the heavier solvent-vapour of the first removal solvent device 10 (solvent-vapour is mixed and fed into airlock 18 with thin slice here).Near solvent trap 30 vertical solvent trap outlets 23 is to be used for producing partial vacuum and remove solvent vapour in solvent trap 30 from system.

Thin slice elevator conveyer 32 is gastight travelling belts, and it is from airlock outlet 18b and solvent trap inlet 30a, and through solvent trap 30 and solvent trap outlet 30b, the inlet 38 of solvent device is removed in arrival second.Thin slice falls from the collecting chamber 31 of airlock 18 to solvent trap 30 bottoms.Elevator conveyer 32 will carry through solvent trap 30 until elevator conveyer outlet 35 at enter the mouth solvent-laden thin slice that 20 airlock outlet 18b falls of elevator conveyer, and thin slice is from dropping into second inlet 38 of removing solvent device 11 here.The major part of solvent-vapour is stayed in the collecting chamber 31 in the collecting chamber 31, and the device/vacuum pump apparatus 21 that is condensed is removed.

Thin slice elevator conveyer 32 can transport thin slice by the travelling belt that has chain 24 (part shows), has cross bar on the chain 24.Chain 24 and cross bar carry thin slice and rise along the bottom of elevator conveyer 32 internal surfaces, the top along elevator conveyer 32 internal surfaces descends simultaneously.Drive sprocket 29 (driving by the motor that does not show among the figure) near elevator conveyer outlet 35 moves chain 24 in elevator conveyer 32.Drive sprocket 26 or groove are fixed on whole elevator conveyer 32 rest parts, can guarantee that like this chain is correctly on the throne, thereby effectively thin slice 20 are transported to outlet 35 from entering the mouth, and simultaneously can prevent that the sloping portion of chain 24 from hooking the rising part of chain 24.Perhaps, can replace chain 24 and cross bar parts with screw rod as travelling belt.

Second remove the inlet 38 of solvent device 11 and solvent outlet 41 preferably be positioned at solvent trap outlet 23 above.So just can limit heavy solvent-vapour and enter the second removal solvent device 11 from airlock 18.Yet possible is, if the feature of suitable arrangement solvent trap 30, this high relative position has not just needed.

More detailed condenser/the vacuum pump apparatus 21 that is connected with the outlet 23 of solvent trap 30 that shown among Fig. 2.Prolong 53 is arranged in the shell 50, and prolong is accepted cold water and is discharged hot water to pipeline 63 from pipeline 60.Liquor pump 58, be connected water vapour Venturi meter on the vacuum port 56 or other vacuum source and prolong 53 all with airlock 18 and 25 synergies, shell 50 in, produce the partial vacuum of about-7.0psig..By exporting 23, remove in the solvent device 11 and produce vacuum at solvent trap 30, elevator conveyer 32 and second.The vacuum that keeps in the shell 50 is extracted the gas in the solvent trap 30 out and is passed prolong 53, and here solvent vapour is condensed into liquid solvent, then in the flow ipe 55.58 solvents with condensation of pump are removed.

Operation

In the operation, enter the inlet 15 of removal solvent device 10 by airlock 12 from the Continuous Flow that contains the solvent thin slice of front solvent extraction process.At this position of process, contain the solvent that accounts for weight 32% in the mixture, be less than 1% oil and about 13% water.So Duo solvent may be for obtain the cause that oil as much as possible carries out solvent washing from thin slice.The temperature of thin slice and solvent is about 142 .Contained solvent and water mainly permeate in thin slice with liquid form.

When thin slice is removed solvent device 10 by first, it is heated, make the temperature of the contained solvent-water mixture of thin slice be increased to about 160  from 142 .This makes most of solvent and the evaporation of some water form solvent-vapour, and this steam first is removed solvent device 10 abrim.Because the boiling point of solvent is lower than the boiling point of solvent, first water vapour of removing in the solvent device 10 is less.The content of solvent very high (about 95%) in this solvent-vapour.

When solvent is removed in the solvent device 10 when liquid is transformed into steam first, solvent-vapour by a roughing pump (not shown) by solvent outlet 13 (arrow demonstrations) extraction.Being used as highly spissated solvent-vapour at outlet 17 steams is collected.By among the figure not device shown solvent can be got off with water condensation and separates, solvent can be reused.Spissated solvent-the vapour of a spot of height leaks from airlock 18 and advances solvent trap 30.

At the end by the first removal solvent device, 10 strokes, thin slice arrives outlet 16.The temperature of thin slice is about 160  on this position, contains the liquid that is made of about 0.7% solvent and 11% water, and this is because most of original solvent and some water gasify in by the stroke of removing solvent device 10, and is being removed by exporting at 13 o'clock.

Thin slice falls 16 and process airlock inlet 18a, the mechanism of airlock 18, the outlet 18b of airlock 18 and the inlet 30a of trap 30 from exporting, in the partial vacuum of final arrival solvent trap 30, arrive the inlet 20 of elevator conveyer then.Leak into airlock 18 owing to unavoidably there is solvent-vapour to remove solvent device 10 from first, the mixture of some highly spissated solvent-vapour also arrives trap 30.Highly spissated solvent-vapour mixture proportion is higher, makes this steam mixture be collected in the collecting chamber 31 of trap 30 approximately with the shown height in dotted line line of delimitation 27.

Thin slice drops on the elevator conveyer chain 24, and the outlet 30b by solvent trap 30 is transported and arrives elevator conveyer outlet 35, and here their are fallen into second through inlet 38 and remove solvent device 11.Enter second remove solvent device 11 after, thin slice has experienced partial vacuum and has removed solvent stage for another of-7psig. in this second device 11.Partial vacuum has reduced liquid solvent and the boiling point of water in the second removal solvent device 11.Therefore evaporate under solvent in the second removal solvent device 11 and the temperature of water in being lower than normal atmosphere.Therefore, second temperature of removing in the solvent device 11 can keep lower, so just can avoid reducing proteinic PDI in the thin slice.

Remove in the stroke of solvent device 11 through second at thin slice, the thin slice temperature is maintained at about 160 .Under the vacuum of-7psig., the boiling point of water is about 180 , and the boiling point of hexane solvent is about 135  here.Because the thin slice temperature is 160 , the reservation solvent evaporation of the overwhelming majority, more water evaporation is also arranged simultaneously.Contain 30% the hexane solvent of having an appointment, 60% water vapour and 10% air in second gas of removing in the solvent device 11.And finding has air in certain amount to enter by the slit of airlock 25 and 28.

Second removes the solvent-vapour that forms in the solvent device 11 is constantly extracted out by solvent vapour outlet 41, and offers solvent trap 30 through pipeline 47, but the also relatively poor method processing of availability of efficient of this steam.With in the trap 30 from first device, 10 vapor phase ratio, in the steam from second device 11, the concentration of solvent is much lower, this is owing to first remove relatively poor the causing of efficient of solvent device 10.Therefore with from first heavier solvent-vapour (bottom at trap 30 is collected) of removing solvent device 10, compare the steam of second device 11 low more than important.Dotted line 27 has shown the representational line of delimitation between two kinds of steam mixtures.

Constantly removing steam with condenser/vacuum pump apparatus 21 from trap 30 can avoid the steam of first device in 10 to enter second device 11 by elevator conveyer 32 or through the backflow of pipeline 47 and steam orifice 41.

It may favourable improvement be to inject a kind of injection gas that the second removal solvent device 11 is carried out one.Spray gas inlet 42 and can be connected to the jet flow stream source, as water vapour (better) or nitrogen.Gas is sprayed in a small amount of injection can improve the amount of removing solvent vapour from thin slice.Spray gas and flow to solvent vapour outlet 41, and enter solvent trap 30 therefrom together with solvent vapour.Suggestion will be sprayed gas inlet 42 and is installed in and remove solvent device 11 and solvent vapour and export on the 41 relative sides.

At the end through second device, 11 stroke, thin slice falls through airlock 25, vacuum chamber 37 and airlock 28 successively, can make the thin slice cooling like this.The most handy vacuum source (not shown) is kept vacuum tightness and second in the vacuum chamber 37, and to remove the vacuum tightness of solvent device similar, leaks second amount of removing the air of solvent device 11 because can reduce like this.

Low treatment temp promptly exports 28b in the exit of thin slice in the solvent device 11 owing to remove, and the PDI level of thin slice is still very high.Because it is very high to remove the operation efficiency of solvent device 11, at airlock outlet 28b place, the solvent that is retained in the thin slice has been reduced to about 300ppm.

Shown condenser/vacuum pump apparatus 21 among Fig. 2 in detail.The steam of extracting out from trap outlet 23 enters the outside of the shell 50 of condenser and the prolong 53 of flowing through by condenser inlet 51.Cooling water inlet 62 enters prolong, and the water of heating then flows out from exporting 63.From 51 solvent vapours that the enter condensation and flow out on the tube wall of prolong 53 that enters the mouth in outlet 52.

The solvent of condensation and water are extracted out from condenser casing 50 by pump 58 by pipeline 55.Pump 58 is reduced to barometric point with the low pressure liquid in the pipeline 55 (mainly being solvent).This liquid is more or less in room temperature.The solvent vapour of water vapour in the shell 50 and air and trace is taken out from pipeline 56 by vacuum source.Necessary, further processing can be removed more water from the solvent of the condensation the pipeline 55.In any case the solvent of condensation can be reused in this course, avoided necessity that spent solvent is handled to small part like this, improved the innocuousness for the treatment of processes simultaneously to environment.Equally, the steam of extracting out from vacuum port 56 also can further be handled, and removes the solvent that wherein still keeps, if negligible words of the content of solvent wherein just can be discharged in the atmosphere legally safely and go.

In a type for the treatment of processes of the present invention, vacuum source is a water vapor venturi apparatus that the principle that basis is known is operated.This vacuum source is favourable, because it does not need moving parts to produce vacuum, has so just increased the reliability of process.Mechanical pump or vent fan also can be used as vacuum source and use.

Claims (11)

1. one kind is removed the removal solvent systems that desolvates from certain solvent-laden particle, comprising:

A) first remove solvent device, and have one to accept solvent-laden particulate inlet, one is expelled to small part and removes the outlet that the particle that desolvates is used, and one is discharged the solvent vapour outlet that solvent vapour is used;

B) first airlock, has the inlet that flows and be connected with first outlet of removing solvent device, also has an outlet, the near small part of described first airlock is removed the particle that desolvates and is sent to the outlet of first airlock from the inlet of first airlock, and can keep the inlet of first airlock and the pressure difference between the outlet at least;

C) solvent trap has a chamber, and entrance and exit protrudes upward from this chamber, and described trap is connected with inlet, is used for accepting particle and steam from the outlet of first airlock, and described trap also has an outlet, for the usefulness that connects vacuum source;

D) second remove solvent device, have one and accept the particulate inlet, discharge for one and finally removed the particulate outlet of desolvating from the solvent trap outlet, and a solvent vapour outlet of discharging solvent vapour;

E) second airlock, have with second and remove the inlet that the solvent device outlet is connected, be used for removing solvent device and accept the final particle that desolvates that removed from second, the final particle that desolvates that removed is discharged in the outlet of second airlock, can keep the inlet of second airlock and the pressure difference between the outlet to small part.

2. removal solvent systems according to claim 1, wherein, described second removes solvent device is equipped with an inlet, and its position is higher than the solvent trap outlet.

3. removal solvent systems according to claim 2 comprises that connecting second removes the steam orifice of solvent device and the pipeline of solvent trap.

4. removal solvent systems according to claim 3, wherein, second steam orifice of removing solvent device is higher than the solvent trap outlet.

5. removal solvent systems according to claim 2, wherein, individual particle elevator conveyer is arranged, it comprises that one is transported to second with particle from the outlet of first airlock and removes the travelling belt pipeline of the sealing of solvent device inlet, and the travelling belt pipeline of described sealing comprises that particle is transported to second from the solvent trap chamber remove the mechanical transmission tape member of the inside of solvent device inlet.

6. removal solvent systems according to claim 5, wherein, the particle elevator conveyer tilts to second inlet of removing solvent device from solvent trap.

7. removal solvent systems according to claim 6, wherein, the solvent trap outlet is positioned near the vertical place of solvent trap.

8. removal solvent systems according to claim 1, wherein, the solvent trap outlet is positioned near the vertical place of solvent trap.

9. removal solvent systems according to claim 1 comprises and placed in-line the 3rd airlock of second airlock.

10. removal solvent systems according to claim 1, wherein, second removes solvent device the individual inlet that sprays source of the gas that is used for connecting.

11. removal solvent device according to claim 10, wherein, the solvent vapour outlet is positioned at a side of the second removal solvent device, sprays the gas inlet and is positioned at a side relative with the solvent vapour outlet side on the second removal solvent device.