Technical Field of the Invention The present invention relates generally to an outlet valve and more specifically to an outlet valve adapted to a bottom part of a vessel, in order to be able to present an outlet of a liquid kept within the vessel, and which outlet valve comprises a movably arranged valve cone and a vessel-allocated fixed valve seat.

By means of an operating device, here in the form of a piston-cylinder arrangement, the valve cone is movably arranged between a first position, se- alingly abutting against the valve seat, and a second, valve-opening position oriented away from the valve seat, or vice versa.

Furthermore, the invention is based on the ability of said valve cone to co-operate with a piston appurtenant to the operating device, which piston divi- des the inner cavity of the cylinder into two chambers, with at least one of said chambers being, via a conduit and a valve, connected to a source of compres- sed fluid.

The invention has been produced with the intention of being able to present a quick emptying of a heated vegetable oil contained in a vessel, pref- erably effective under a negative pressure or compelled via negative pressure.

Background of the Invention Methods and arrangements of the above-mentioned nature and for the above-given purpose are previously known in a plurality of different embodi- ments.

As a first example of the background of the invention and the technical field to which the invention relates, the content of the Swedish Patent Publica- tion 515 606 may be mentioned.

Here, an outlet valve is shown and described, which is arranged to a bottom part of a vessel, intended to be filled with liquid, and which comprises a valve head (1) connected to a piston rod (4) and a compressed fluid-actuated

piston (5), and which valve head (1) is movably arranged between a first and a second position and is arranged to closely abut against a fixed valve seat (2) in a first closed position.

Here, it is specially taught that the piston (5) is arranged in an operat- ing device (6) provided with two connections (7,8) to sources of compressed fluid.

In this case, the operating device (6) is formed as a unit sealed aga- inst the liquid and surrounded by the liquid, and is furthermore fixedly united with the valve seat (2).

Like the present invention, said embodiment has been shown to be applicable within refining plants for vegetable oils, and where a special appli- cation is a deodorization, but the invention may likewise come to use in the bleaching and/or hardening of such vegetable oils.

As further examples of previous prior art, reference can be made to the following patent publications.

US-A-3 949 963, US-A-3415486, and<BR> US-A-3 126 022.<BR> <P>US-A-3 126 022.<BR> <P>Technical Problems If attention is paid to the circumstance that the technical considerati- ons a person skilled in the relevant technical field has to make, in order to be able to present a solution to one or more technical problems raised, initially are a necessary insight in the measures and/or the sequence of measures that should be taken as well as a necessary choice of the means that is or are required, the subsequent technical problems should, in view of this, be rele- vant in the creation of the present subject of invention.

While taking prior art into consideration, as it has been described abo- ve, it should, therefore, be seen as a technical problem to be able to realize the significance of and the advantages associated with being able to cause a discharge via an outlet valve, adapted to the bottom part of a vessel, of a liquid kept within the vessel, and which outlet valve should comprise a movable val- ve cone and a vessel-allocated fixed valve seat, the valve cone, by means of

an operating device, in the form of a piston-cylinder arrangement, being mo- vably arranged between a first position, sealingly abutting against the valve seat, and a second, valve-opening position oriented away from the valve seat, or vice versa, and where said valve cone co-operates with a piston appurte- nant to the operating device, which piston divides the inner cavity of the cy- linder into two chambers, with at least one of said chambers being, via a con- duit and a valve, connected to a source of compressed fluid, to allow said val- ve cone to be given a cup or cone shape, the opening-peripheral edge surface of which should be adapted to serve as a sealing surface against the fixed val- ve seat and where the cup shape in other respects should be dimensioned in order to be able to surround and contain said operating device.

There is a technical problem to be capable of realising the significance of and the advantages associated with allowing the shape of the valve cone to be dimensioned to likewise, in said second position, be able to surround and enclose said operating device.

There is a technical problem to be capable of realising the significance of and the advantages associated with allowing a cylinder unit appurtenant to the operating device to be fixedly related to the bottom part of a vessel via at least two, preferably three, supports converging from the bottom.

There is a technical problem to be capable of realising the significance of and the advantages associated with allowing preferably two of said supports to be given the shape of pipes, one of the respective end portions of which is adapted to communicate with one of the two cylinder chambers divided by the piston, and the respective opposite other end portion of which is adapted to co-operate with said valve via a conduit external to the vessel.

There is a technical problem to be capable of realising the significance of and the advantages associated with allowing said valve cone to be given a shape that may regarded to consist of a cylindrical portion, integrally formed with a somewhat upwardly (facing from the valve seat) bent roof portion cov- ering an upper limiting surface of the cylindrical portion.

There is a technical problem to be capable of realising the significance of and the advantages associated with allowing a piston rod, appurtenant to the piston of the operating device, to be fastened, in the end portion thereof oriented outside the cylinder, to a central area allocated to said roof portion.

There is a technical problem to be capable of realising the significance of and the advantages associated with allowing at least three support means, for a reciprocating motion of the valve cone, to be fastened to the inside of said cylindrical portion of the valve cone.

There is a technical problem to be capable of realising the significance of and the advantages associated with allowing the inwardly facing end porti- ons of the support means to be adapted to exhibit slide and/or support surfa- ces, adapted to slidingly abut against, or adapted to solely face against, an ou- ter surface allocated to the cylinder portion of the operating device.

There is a technical problem to be capable of realising the significance of and the advantages associated with, in said first position, allowing said val- ve cone to be surroundable by a liquid given a high temperature, say at least above 200 °C, alternatively that said liquid should consist of a vegetable oil of a selected temperature regulated to between 250 and 280 °C.

There is a technical problem to be capable of realising the significance of and the advantages associated with allowing to allocate an adapted negati- ve pressure to an inner volume of an outlet pipe, in order to thereby shorten the discharge time.

There is a technical problem to be capable of realising the significance of and the advantages associated with allowing said negative pressure to be- come effective downstream the valve cone, immediately after the valve cone has left its co-operation thereof with the valve seat.

Furthermore, there is a technical problem to be capable of realising the significance of and the advantages associated with, upon a displacement of said valve cone from said first position to said second position by means of said operating device, allowing to apply a positive pressure to one of cylinder- appurtenant chambers, from a first source of compressed fluid, and a negative pressure to the other cylinder-appurtenant chamber, from a second source of compressed fluid, via a simultaneous action and activation of a valve, each al- located to the sources of compressed fluid.

There is a technical problem to be capable of realising the significance of and the advantages associated with, during an occurring quick emptying sequence of contained liquid from the vessel, allowing to create conditions for

a synchronized performance and increasing negative pressure downstream the valve cone.

In addition, there is a technical problem to be capable of realising the significance of and the advantages associated with allowing the valve cone and the valve seat in said first position to be in co-operation with a process- allocated negative pressure, provided via a gas phase, such as steam, inert gas, and in exceptional cases air, allocated a temperature of at least above 100 °C, such as between 100 and 200 °C.

There is a technical problem to be capable of realising the significance of and the advantages associated with allowing said negative pressure to be adapted for, among other things, creating a selected reduction of occurring transmission of heat via convection.

In addition, there is a technical problem to be capable of realising the significance of and the advantages associated with allowing the distance, be- tween the first and the second position of the valve cone in relation to the val- ve seat, to be adapted to allowing to comply with, by a factor of 3 to 6, a selec- ted maximum distance between opposite surface portions (such as diametri- cally related surface portions) of the valve seat.

The Solution In that connection, the present invention starts out from the prior art ta- ught by way of introduction, where an outlet valve adapted to the bottom part of a vessel should be adapted in order to be able to present a discharge of a liquid kept within the vessel, and which outlet valve comprises a movable val- ve cone and a vessel-allocated fixed valve seat, the valve cone, by means of an operating device, in the form of a piston-cylinder arrangement, being mova- bly arranged, between a first position, sealingly abutting against the valve seat, and a second, valve-opening position oriented away from the valve seat, or vice versa, and where said valve cone co-operates with a piston appurte- nant to the operating device, which piston divides the inner cavity of the cylin- der into two chambers, with at least one of said chambers being, via a conduit and valve each, connected to a source of compressed fluid.

In order to be able to solve one or more of the above-mentioned tech- nical problems, in particular the present invention teaches that the prior art

should be supplemented in that said valve cone should be given a marked cup and/or cone shape, the opening-peripheral edge surface of which should be a- dapted to serve as a sealing surface against the valve seat, and that the sha- pe of the valve cone in other respects should be dimensioned in order to be able to surround and contain said operating device.

As proposed embodiments, coming or falling within the scope of the basic idea of the present invention, it is taught that the shape of the valve cone should be dimensioned, likewise in said second position, to be able to surro- und said operating device.

Furthermore, it is taught or suggested that a cylinder unit appurtenant to the operating device should possible be fixedly related to the bottom part of the vessel via, at least two, supports, converging from the bottom part.

At least two of said supports have been given the form of a pipe, one end portion of which is adapted to be able to communicate with one of the two cylinder chambers divided by the piston, and the opposite second end portion of which is adapted to co-operate with said valve via a pipe section.

In addition, said valve cone may be given a shape, which can be re- garded to consist of a cylindrical portion integrally formed with a somewhat convexly bent roof portion covering the cylindrical portion.

Furthermore, it is taught or suggested that a piston rod appurtenant to the operating device piston, in the end portion thereof oriented outside the cylinder, may be attached to a central area allocated to the roof portion.

A number of support means may be attached to the inside of said val- ve cone, such as to the cylindrical portion thereof, wherein the inwardly facing end portions of the support means may be adapted to exhibit slide and/or sup- port surfaces, adapted to be able to slidingly abut against or facing against an outer surface allocated to the cylinder portion of the operating device.

A special application is that said valve cone in said first position should possible be surroundable by a liquid given a high temperature, say above 200 °C, alternatively that said liquid should be possible to consist of an oil, such as vegetable oil, animal oil or another equivalent product, having a tem- perature of for instance between 250 and 280 °C.

Furthermore, it is taught or suggested that, downstream the valve co- ne and with the same taking a first position abutting against the valve seat, a negative pressure should occur within an outlet pipe.

According to the present invention, furthermore it is suggested that u- pon a displacement of said valve cone from said first position to said second position by means of said operating device, a positive pressure is applied to one of the chambers appurtenant to the operating device, from a first source of compressed fluid, and a negative pressure, alternatively atmospheric pressu- re, is applied to the second chamber, from a second source of compressed fluid, via a simultaneous action of a valve each allocated to the sources of compressed fluid.

During an occurring quick emptying sequence, via the outlet pipe, of contained liquid from the vessel, a selected negative pressure should occur downstream of the valve cone.

The valve cone and the valve seat should in said first position be able to c-operate with an adapted negative pressure of a gas mixture allocated a temperature of somewhat above 100 °C, such as 100 to 200 °C, with said negative pressure, while the process is in progress, being adapted to, among other things, be able to reduce a transmission of heat via convection.

More specifically, the dimensioning rule that the distance between the first and the second position of the valve cone in relation to the valve seat sho- uld be adapted to be able to comply with, by a factor of 3 to 6, a selected dis- tance between opposite surface portions of the valve seat is taught.

Advantages The advantages that foremost can be regarded as characteristic of the present invention and the special significative features provided thereby, are that, in this way, conditions have been created in order for enabling an outlet valve to be operated very quickly via an operating device, and thereby, a ves- sel may be completely emptied of its contained liquid very quickly.

The operation of the operating device may be quickly effected by the application of a negative pressure and a positive pressure to respective cylin- der chamber within the utilized piston-cylinder arrangement, and by the fact that said valve cone is given a shape, the opening-peripheral edge surface of

which should be adapted to serve as a sealing surface against the valve seat, and that the shape of the valve cone in other respects is dimensioned in order to be able to surround and contain said operating device.

What foremost can be regarded as characteristic of an outlet valve ac- cording to the present invention is defined in the characterizing clause of the appended claim 1.

Brief Description of the Drawings A presently proposed embodiment, having the significative features associated with the present invention, will now for the purpose of exemplifying be described more closely, reference being made to the accompanying draw- ing, where : Figure SI shows, in side view, a lower part of a vessel having an outlet pipe connected thereto, and illustrating the utilization of an outlet valve, of a construction that complies with what should be hold for an outlet valve according to the invention, Figure 2 shows, in a vertical cross-sedion, an outlet valve construdea accor- ding to the advice given by the invention, however, only one of three supports is illustrated, in the form of a pipe, Figure 3 shows, in a somewhat enlarged view, an alternative part of the outlet valve according to figure 2, and Figure 4 shows a horizontal view of the outlet valve, according to figure 2.

Description of Presently Proposed Embodiment It should then by way of introduction be emphasized that in the subse- quent description of a presently proposed embodiment, which has the signifi- cative features associated with the invention and which is elucidated by the figures shown in the appended drawings, we have chosen terms and a parti- cular terminology with the intention to thereby primarily allow to make clear the fundamental idea of the invention.

It should, however, in this connection be taken into consideration that expressions chosen here should not be seen as limiting solely to the terms uti- lized and chosen here, but it should be understood that each term chosen in this manner should be interpreted so that it, in addition, comprises all technical equivalents that operate in the same or substantially the same way, in order to, in this way, enable the achievement of the same or substantially the same intention and/or technical effect.

With a reference to figure 1, there is schematically shown the funda- mental conditions for the present invention and with the significative peculiari- ties or features associated with the invention generally having been made con- crete, by a presently proposed embodiment shown more closely in the follo- wing, in appended drawings and described more closely in the following desc- ription.

Accordingly, figure 1 shows, in side view, the lower part of a vessel 1, having an outlet pipe 2 connected thereto, and illustrating the utilization of an outlet valve 3 connected to or adapted to the bottom part 1 a of the vessel 1, of a construction that complies with what should be hold for an outlet valve ac- cording to the instructions and features of the invention and illustrated by the drawing figures 2 to 4.

Accordingly, figure 2 shows a vertical cross-section through the outlet valve and with only one (out of three) support in the form of a pipe being shown, figure 3 shows an enlarged view of a somewhat modified part of the outlet valve, with the pipe being attached to the operating device, and figure 4 shows a horizontal view of the outlet valve 3.

The deodorization plant (15), shown in figure 2 in the above-mentio- ned Swedish Patent specification, may in principle come to a use also for the present invention, with the vessel 1, on that occasion, being assignable to the third space (26).

The outlet valve 3 adapted to the bottom part 1 a of the vessel 1 is di- mensioned in order to be able to present a very quick discharge of a liquid 4 kept within the vessel, and which outlet valve 3 comprises a movably arranged valve cone 3a and a vessel-allocated fixed valve seat 3b, the valve cone, by means of an operating device 5, in the form of a piston-cylinder arrangement, 3a being movably arranged between a first position, sealingly abutting against

the valve seat and more closely shown in figure 2, and a second, valve-open- ing position, oriented away from the valve seat, only marked by a line 6 in fig- ure 2, or vice versa.

Said valve cone 3a co-operates with a piston 5a appurtenant to said operating device 5, which piston divides the inner cavity of a cylinder 5b into two chambers, designated 51 and 52, with each one of said chambers 51 and 52 being connected to a source of compressed fluid (not shown) via a conduit each, 7a and 7b, respectively, and a valve (not shown).

Accordingly, in figure 2 it is shown that the chamber 51 is in connecti- on with a pipe 7a, serving as a support, and in figure 3 it is shown that the chamber 52 is in connection with a pipe 7b, serving as a support.

The pipe 7a is connected to a supply pipe 7a3, the end portion (not shown) of which co-operates with a valve (not shown), connected to a source of compressed fluid for negative pressure.

Two additional supports are not shown in figure 2, but figure 4 illus- trates the utilization of a support 7b in the form of a pipe, and like the pipe 7a, this is connected to a supply pipe (not shown), the end portion of which co- operates with a valve (not shown) connected to a source of pressure for posi- tive pressure.

Said valve cone 3a is given a formalized cup and/or cone shape, the downwardly directed opening-peripheral edge surface 3a'of which is adapted to serve as a sealing surface against the valve seat 3b, and that the shape of the valve cone in other respects is dimensioned in order to be able to entirely surround and contain details co-ordinated within the interior of the valve, either by a tight shape, or, as the embodiment example implies, an adapted large shape and by an adapted volume surrounding said operating device 5.

The outer shape for the valve cone 3 should primarily be selected in order to be able to control the quick outflow of the liquid 4 from the vessel 1, and where the outer shape also should pay regard to and comply with the shape of the vessel for the bottom part next to the outlet valve and the flow pattern that an open outlet valve will give.

Likewise in said second position 6, the shape of the valve cone 3a is furthermore dimensioned in order to be able to surround said operating device 5, in order to partly expose but yet protect this operating device from liquid,

when the liquid 4 is to run quickly through the outlet valve 3 and the outlet pipe 2.

Within a selected process plant, a selected and equal negative pres- sure may be prevailing within the vessel 1 as well as within the outlet pipe 2.

This means that the operating device 5 does not necessarily need to be protected from liquid or constructed as a unit sealed against liquid.

A cylinder unit 5b appurtenant to the operating device 5 is fixedly related to the bottom part 1 a of the vessel via, at least two, supports converg- ing and conveniently distributed from the bottom part 1a, with the three sup- ports shown here having been given the reference designations 7a, 7b and 7c, respectively.

Said supports 7a, 7b and 7c, respectively, should be dimensioned to be thin and of a minimum suitable number, since they otherwise prevent a co- ordinated outflow of liquid 4a through the outlet valve 3.

At least two of said supports, given the reference designations or nu- merals 7a and 7b, have been given the shape of pipes, one end portion of which, such as 7a1 in figure 2, is adapted to communicate with one, 51, of the two cylinder chambers 51 and 52 divided by the piston 5a, and the opposite second end portion of which, such as 7a2, is adapted to co-operate with the valve not shown via said pipe section 7a3.

In figure 3, it has been illustrated how a support 7b in the form of a pipe communicates with the cylinder chamber 52.

By applying a positive pressure to the chamber 52 (see figure 3) via a valve, the piston 5a is displaced upwards, and air contained in the chamber 51 can be evacuated via conduits 5b2 and 5b3 in figure 2.

If a positive pressure is applied to the chamber 51, upon an entirely open valve cone 3, the piston 5a is pressed downwards and the chamber 52 is evacuated.

For this, a co-ordinated valve arrangement of known type is required.

Said cup-shaped or conical valve cone 3a is given a shape that can be regarded to consist of a cylindrical portion 3a1 integrally formed with a some- what convexly bent roof portion, designated 3a2, covering the cylindrical por- tion 3a1.

A piston rod 5a1 appurtenant to the piston 5a of the operating device 5 is in the end portion 5a2 thereof, oriented outside the cylinder, attached to a central area 3a2 allocated to the roof portion 3a2.

At least two, here shown as three, support means 8a, 8b and 8c, are attached centrally oriented to the inside 3a1'of said cylindrical portion 3a1.

The inwardly facing end portions 8a1, 8b1 and 8c1 of the support me- ans 8a, 8b and 8c are adapted to exhibit slide and/or support surfaces, adap- ted to slidingly abut against or facing against an outer surface 5b1 allocated to the cylinder portion 5b of the operating device.

The embodiment shows that said end portions 8a1, 8b1 and 8c1 are co-ordinated into a ring-shaped means 8d, tightly but slidingly surrounding the cylinder portion 5b.

In said first position, shown in figure 2, said cup-shaped valve cone 3a is surroundable by a liquid 4, which may be given a relatively high temperatu- re, say above 200 °C, In the particular application, said liquid may consist of a vegetable oil having a temperature, in a deodorization plant, of between 250 and 280 °C.

Downstream the valve cone 3a and with the same taking a first posi- tion, abutting sealingly against the valve seat 3b, conditions may be provided for an occurrence of an adapted negative pressure in the outlet conduit, in the area designated 2a in figure 2.

Means for adjustably providing this negative pressure are not shown, but may be generated in known ways, per se, and upon the utilization of me- ans that are known, per se.

Such a negative pressure, together with a quick actuation of the outlet valve 3, can provide conditions for considerably shortening the emptying time of the liquid 4 and the volume thereof within the vessel 1.

Upon a quick displacement of said valve cone 3a from said first posi- tion, according to figure 2, to said second position 6, illustrated in figure 2, by means of said operating device 5, a positive pressure is applied to one of the two chambers, here, the chamber 52 is selected, via the pipe-shaped support 7b from a first, not shown, source of compressed fluid and a negative pressure to the opposite second chamber 51, via the pipe-shaped support 7b, from a

second, not shown, source of compressed fluid via a simultaneous action of a valve each, and neither shown, allocated to the sources of compressed fluid.

Upon a closing, an opposite action takes place.

During an occurring quick emptying sequence of contained liquid 4 from the vessel 1, via the outlet valve 3 and the outlet pipe 2, an adapted ne- gative pressure may occur downstream the valve cone 3a, within the space 2a.

In said first position, the valve cone 3a and the valve seat 3b are, ac- cording to figure 2, in a co-operation with a seal-improving negative pressure, and a gas mixture utilized herefor can, for the given application, be allocated a temperature of above 100 °C, say between 100 and 200 °C.

Even if a temperature gradient is at hand between the liquid 4 and a space (3a) contained by the valve cone 3a, the selected negative pressure will, among other things, help to reduce a heat transfer and transmission of heat via convection.

The distance between the first (shown in figure 2) and the second po- sition (the reference designation 6 in figure 2) of the valve cone 3a in relation to the valve seat 3b is adapted to comply with, by a factor of between 3 to 6, preferably about 4, a selected distance between opposite surface portions 31 and 32 of the valve seat 3b.

The invention is of course not limited to the embodiment given above as example, but may be subjected to modifications within the scope of the ge- neral idea according to the invention, illustrated in the subsequent claims.

Particularly, it should be taken into consideration that each unit shown may be combined with each another unit shown within the scope of the inven- tion in order to be able to attain the desired technical function.

Even if the outlet valve 3 has been described in connection with a po- sitioning above a vessel-allocated, bottom-appurtenant outlet opening 2a, it should be taken into consideration that nothing precludes locating the same at the underside of this opening, but with design alterations natural to a person skilled in the art.

Furthermore, the shape of the valve cone 3 may be varied within the scope of the invention.

Accordingly, it would be possible to give a lower part the shape of a truncated cone, in order to, in a closed position of the valve, connect tightly to the supports 7a, 7b and 7c and having an upper part attached thereto, given the shape of a cylinder having a roof portion in order to tightly surround the operating device 5.

Different possibilities to allow to shape the valve cone 3 so that the outer surface thereof will be able to form flow guiding wings or strips for the liquid during the emptying sequence fall within the scope of the invention.