GB2024158A - Metering device - Google Patents
Metering device Download PDFInfo
- Publication number
- GB2024158A GB2024158A GB7847173A GB7847173A GB2024158A GB 2024158 A GB2024158 A GB 2024158A GB 7847173 A GB7847173 A GB 7847173A GB 7847173 A GB7847173 A GB 7847173A GB 2024158 A GB2024158 A GB 2024158A
- Authority
- GB
- United Kingdom
- Prior art keywords
- recess
- valve
- plug
- stem
- plug stem
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
- G01F11/00—Apparatus requiring external operation adapted at each repeated and identical operation to measure and separate a predetermined volume of fluid or fluent solid material from a supply or container, without regard to weight, and to deliver it
- G01F11/10—Apparatus requiring external operation adapted at each repeated and identical operation to measure and separate a predetermined volume of fluid or fluent solid material from a supply or container, without regard to weight, and to deliver it with measuring chambers moved during operation
- G01F11/12—Apparatus requiring external operation adapted at each repeated and identical operation to measure and separate a predetermined volume of fluid or fluent solid material from a supply or container, without regard to weight, and to deliver it with measuring chambers moved during operation of the valve type, i.e. the separating being effected by fluid-tight or powder-tight movements
- G01F11/20—Apparatus requiring external operation adapted at each repeated and identical operation to measure and separate a predetermined volume of fluid or fluent solid material from a supply or container, without regard to weight, and to deliver it with measuring chambers moved during operation of the valve type, i.e. the separating being effected by fluid-tight or powder-tight movements wherein the measuring chamber rotates or oscillates
Landscapes
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- General Physics & Mathematics (AREA)
- Filling Or Emptying Of Bunkers, Hoppers, And Tanks (AREA)
Abstract
A device for metering small quantities of a fine powder, or a mixture of a powder and a liquid medium containing a large proportion of powder, for example titanium trichloride or a mixture with an inert liquid medium, comprises a plug valve in which the plug is a solid unit (2) having at least one recess (3) therein, the recess or recesses being arranged to be in alignment with alternatively the inlet and outlet ports of the valve. The recess can be small and contain only small quantities of the powder. The plug may have several recesses around its perimeter. The plug stem can be rotated intermittently or continuously or can be oscillated. The rate at which the plug stem is rotated or oscillated is dependent on the rate at which it is desired to meter the powder. The valve body can be provided with channels (16), (17) for purging and/or venting the recess. A device of this type can be arranged to deliver as little as 0.08 gram of titanium trichloride powder over a period of 10 minutes. <IMAGE>
Description
SPECIFICATION
Metering device
The present invention relates to devices for metering powders or mixtures of powders and a liquid medium and is particularly concerned with devices which are suitable for metering small quantities of fine powder materials.
A wide range of devices are available commercially for metering of powdered materials, but such devices do not seem capable of metering such fine powders at a very low rate, for example at a rate of less than 1 gram per hour, particularly if there is a pressure difference between the inlet and outlet sides of the metering device. Furthermore, since such fine powders are frequently abrasive there are problems with sealing in such metering devices and thus it is desirable to minimise the amount of sealing which is required since otherwise there may be considerably periods of time in which the device is not available for use due to a need to repace sealing mechanisms.
According to the present invention there is provided a metering device which comprises a plug valve having a valve body and a solid plug stem wherein at least one recess is formed in the circumferential surface of the plug stem, said, or each, recess being positioned to be aligned, in turn, with an inlet port and an outlet port in the valve body.
There may be only one recess in the plug stem, but the plug stem may be provided with two, four, six, eight, or even more recesses around its circumference. The number of recesses provided will be dependent in part on the size which it is desired to make each recess and also on the circumference of the plug stem. The number of recesses will be dependent also on the manner in which the metering device is operated, as will become more apparent hereafter. If the plug stem is provided with more than one recess, the recesses are spaced sufficiently apart so that only one recess is aligned with either the inlet port or the outlet port at any time. It is especially preferred that one recess is aligned with the outlet port when another recess is aligned with the inlet port.
The plug stem of the metering device is preferably arranged to operate in the horizontal plane. The inlet port is located above the plug stem and the outlet port is at the bottom, conveniently diametrically opposite the inlet port.
The plug stem can be rotated continuously but it is preferred either to rotate the stem intermittently or, when no more than two recesses are in the plug stem, to oscillate the stem through 1 80o. However, if purging and venting of the recesses are desired, as discussed in more detail hereafter, oscillation of the valve stem should be avoided and the valve stem is preferably rotated intermittently. The rate at which the device meters the powdered material depends on the size of each recess, the number of recesses around the circumference of the plug stem and also on the rate of rotation, or the frequency of oscillation, of the plug stem. These three factors can be adjusted to give the desired rate of metering.
Typically, with any given valve the metering rate is controlled by the rate of rotation, or frequency of oscillation, of the plug stem.
It is preferred that there are no sharp corners in the recesses, which may be of any desired cross-section such as circular or essentially square or rectangular.
The base of each recess may be spherical or similarly curved. The upper portion of each recess, extending to the surface of the plug stem, preferably has walls which are essentially normal to the surface of the plug stem. The top of the walls of each recess are preferably curved to eliminate sharp edges at the opening in the recess. Typically, the depth of each recess is at least 0.5 mm. If the plug stem is provided with more than one recess, the maximum depth of each recess should be slightly less than the radius of the plug stem and should be such as to provide a solid central portion in the plug stem which is capable of withstanding any pressure difference established across the metering device. If the plug stem is provided with only one recess, this recess can be deeper than the radius of the plug stem.The cross-sectional dimensions of the recess depend on the cross-sectional shape of the recess but it is preferred that, at the surface of the plug stem, the recess has a dimension around the circumference of from 0.5 mm up to half the diameter of the plug stem. The diameter of the plug stem is typically from about 1 cm up to about 15.0 cm, or even more. The plug stem may be tapered and it should be appreciated that the term "diameter" or "radius" when used for such a tapered plug stem refers to the mean diameter or mean radius. It will beappreciatedthat the capacity of each recess is dependent on the packing density of the powder to be metered and thus for any given powder it will be necessary to determine the rate at which this particular powder is metered as a preliminary calibration.
Since the valve at no time provides a direct passageway from the inlet port to the outlet port, it is possible to operate the valve with a pressure differential between the inlet and outlet ports. Thus, one side of the valve can be operated at a pressure which is considerably higher than the other side of the valve. Thus, one side of the valve may be operated at essentially atmospheric pressure whilst the other side of the valve may be operated at superatmospheric pressure, for example at a pressure of about 35 atmospheres.
The metering device of the present invention can be used to meter fine solids such as finely-divided olefin polymerisation catalysts, or components thereof, for example titanium trichloride or a supported catalyst system wherein the support is, for example, silica or alumina. Thus, the inlet port of the valve may be connected to a hopper containing titanium trichloride powder maintained in an atmosphere of nitrogen or a similar inert gas whilst the outlet port of the valve may be connected to a supply of liquid propylene monomer. Typically, with such an arrangement, the pressure in the hopper will be slightly in excess of atmospheric pressure, for example 1.5 atmospheres absolute, whilst the pressure of the liquid propylene may be a high as 35 atmospheres.Using such an arrangement the meter ing device meters one component of the polymerisation catalyst (titanium trichloride) into the propylene monomer which then carries it to a propylene polymerisation reactor. The metering devices providess a predetermined slow rate of feed of the titanium trichloride into the propylene monomer which is highly desirable for polymerisation systems in which a high yield of polypropylene is obtained compared to the quantity of catalyst being used, and in which failure to control the rate of catalyst feed with accuracy cou Id resu It in erratic variations in the rate of polymerisation and in the nature of the product formed.The metering device has also been used effectively for metering a concentrated suspension of a powder in an inert liquid medium, for example a suspension of titanium trichloride in an inert aliphatic hydrocarbon wherein the concentration of titanium trichloride in the suspension is greater than 25% by weight of the weight of the suspension.
Since the metering device may be used to meter a solid into a medium with which the solid is reactive, for such a use it is necessary to ensure that there is essentially no back flow of the reactive medium into the vessel from which the solid is being metered. It is also desirable to minimise the quantity of solid which lodges in a recess and does not readily fall out.
To minimise the lodging of solid in a recess, the surface of the recess may be coated with a material having a low coefficient of friction, for example a tetrafluoroethylene polymer. Alternatively, if a flow of gas or liquid is provided to transport the solid away from the outlet port, this flow of gas or liquid can be directed into each recess as it becomes aligned with the outlet port, the flow of gas or liquid around the recess aiding in dislodging of the solid from the recess. The flow of gas or liquid can be directed into the recess through a channel formed through the valve body, the channel being aimed towards the position of a recess when the latter becomes aligned with the outlet port.The opening of the channel within the valve body is preferably arranged to communicate with the outlet port at all times whereby there can be a continuous flow of gas or liquid through the channel and into the outlet port.
To minimise back flow of the reactive medium, a further channel may be formed through the valve body, this further channel being adapted to be connected to a low pressure region and being located within the valve body to communicate with a recess when the recess is isolated from both the inlet and outlet ports of the valve. When the recess is in communication with the further channel, the recess is evacuated to a low pressure which is conveniently below that at the inlet port. To achieve effective evacuation of the recess, it is desirable that each recess is stopped opposite the further channel. If the valve stem is provided with only one recess, it is convenient for the rest position of the valve stem to be such that the recess communicates with the further channel in the rest position.When the valve is operated, the valve stem is rotated to align the recess first with the inlet port, then with the outlet port and finally back to the rest position opposite the further channel. It will be appreciated that to achieve effective evacuation, the plug stem must always be rotated in the same direction and the direction of rotation must be such that the recess is aligned with the outlet port, before it is aligned with the further channel.
To provide improved sealing between the valve body and the valve stem, a sealing bush can be located between the valve body and the valve stem.
The sealing bush can be formed of any suitable material, for example polytetrafluoroethylene filled with glass fibre.
In order to more fully describe the present invention reference will now be made to the accompanying drawings wherein:
Figure 1 is a diagrammatic cross-section of a plug valve in accordance with the present invention;
Figure 2 is a diagrammatic cross-section of an alternative form of a plug valve in accordance with the present invention;
Figure 3 is a magnified cross-section of a plug stem showing a recess in more detaii; Figure 4 is a plan view of a plug stem showing one shape of recess;
Figure 5 is a magnified cross-section along the length of a plug stem showing an alternative form of recess;
Figure 6 is a plan view of the plug stem of Figure 5;
Figures 7, 8 and 9 are diagrammatic cross-sections of an alternative form of plug valve showing the valve stem in different positions; and
Figure 10 is a cross-section along the line A-A in
Figure 7, in the absence of the valve stem.
In Figure 1, the metering device comprises a valve body 1 having a plug stem 2 which is capable of rotation, or oscillation, within the valve body. On the plug stem 2 are formed four recesses (3,4,5,6). An inlet conduit 7 is fixed to the upper portion of the valve body 1 and this is aligned with an inlet port 8 to the valve. An outlet conduit 9 is located to the lower portion of the valve body and this connects to an outlet port 10.
In the arrangement of Figure 2, corresponding parts are labelled as in Figure 1. In this arrangement there are only two recesses (3 and 4) in the plug stem 2.
In Figure 3, the recess has a lower surface 11 which is essentially spherical in form, whilst the upper section 12 is in the form of a cylinder, the sidesof which are essentially normal to the circumferential surface ofthe plug stem 2, and are curved into the surface of the plug stem 2. There are no sharp corners between the surface 11 and the upper section 12, or between the upper section 12 and the surface of the plug stem 2.
In Figure 4, each recess has a circular cross-section as shown at 4.
In Figure 5, each recess (3 and 4) is a groove, and has a lower surface 13 which is essentially flat and curves into the walls defining the upper portion 12 of the recess. The upper portion 12 is curved into the upper surface ofthe plug stem 2.
In Figure 6, the recess 4 is formed with curved ends 14, thus avoiding any sharp corners.
In Figures 7 to 10, the plug stem 2 has a single recess (3), which has a depth greater than the radius of the plug stem 2. Between the valve body 1 and the plug stem 2 is located a sealing bush 15. Through the side of the valve body 1 are formed two channels 16 and 17. The channel 16 passes horizontally through the valve body 1 at a point level with the axis of the plug stem 2 and in a direction at right angles to the axis of the plug stem 2. The channel 17 passes upwardly from the exterior of the valve body 1 and, its inner end, the channel 17 communicates with the outlet port 10 to give a common opening at the valve stem 2. In Figure 7, the valve stem 2 is in the rest, or vent, position with the recess 3 communicating with channel 16. In Figure 8, the valve stem 2 is in the charging position, with the recess 3 communicating with inlet port 8.In Figure 9, the valve stem 2 is in the discharging position, with the recess 3 communicating with both the outlet port 10 and the inner end of the channel 17.
In Figure 10, the combined opening of outlet port 10 and the channel 17 can be seen.
In all of the arrangements illustrated, the inlet conduit 7 is connected to a hopper (not shown) containing the material to be metered. The outlet conduit 9 is connected to a transfer conduit (not shown) through which the material is conveyed to, for example, a polymerisation vessel.
In the arrangements illustrated in Figures 7 to 10, the channel 16 is connected to a conduit (not shown) which leads to a vacuum pump. The channel 17 is connected to a conduit (not shown) which leads from a source of a conveying fluid.
In operation of the arrangement shown in Figure 1, the plug stem 2 is rotated, either continuously or intermittently, and each of the recesses 3,4,5 and 6 is aligned, in turn, with the inlet port 8 and subsequently with the outlet port 10. The shaping of the recesses is such that the powder flows into, and out of, each one readily and without blocking.
In operation of the arrangement shown in Figure 2, the plug stem 2 is rotated, for example clockwise, through 180 so that recess 4 moves from the top to the bottom and recess 3 from the bottom to the top.
After a predetermined time, the plug stem 2 is rotated in the opposite direction, that is anticlockwise, through 180 to move recess 3 from the top to the bottom and recess 4 from the bottom to the top.
To improve the flow of the powder into each recess as it becomes aligned with the inlet port 8, the inlet conduit 7 may be connected to a vibrating hopper containing the powder to be metered.
To improve the removal of the powdered material from a recess as it becomes aligned with the outlet port 10 the arrangement of Figures 7 to 10 can be used in which a channel is bored through the valve body 1 to connect with the outlet conduit 9 at a point adjacent to the outlet port 10. Through this channel (channel 17 in Figures 7 to 10) there may be passed any suitable fluid, for example liquid propylene or gaseous ethylene, and the channel 17 is aligned such that the flow of this fluid is directed into a recess as it becomes aligned with the port 10. The channel 17 is arranged so that a continuous flow of fluid is possible, at all times, through channel 17 to outlet port 10 and thence along outlet conduit 9, even when there is no recess aligned with the outlet port 10.
The rest position of the valve is shown in Figure 7 in which the recess 3 is in communication with a vacuum pump through the channel 16. Thus, in the rest position, the recess 3 is evacuated and any reactive fluid carried round from the discharge position (shown in Figure 9) is essentially removed from the recess 3. The valve stem 2 is rotated anti-clockwise to the charging position (Figure 8), on to the discharging position (Figure 9), and finally returns to the rest position (Figure 7) and stops.
A metering device in accordance with the present invention has been used to meter titanium trichloride into a gas-phase propylene polymerisation vessel. The device has given reliable operation over a period of several months.
It will be appreciated that other variations may be effected without departing from the scope of the invention as claimed herein.
Claims (10)
1. A metering device which comprises a plug valve having a valve body and a solid plug stem wherein at least one recess is formed in the circumferential surface of the plug stem, said, or each, recess being positioned to be aligned, in turn, with an inlet port and an outlet port in the valve body.
2. A device as claimed in claim 1 wherein a sealing bush is located between the valve stem and the valve body.
3. A device as claimed in claim 1 or claim 2 wherein there is only one recess in the plug stem.
4. A device as claimed in claim 1 or claim 2 wherein there are two recesses in the plug stem and means are provided to oscillate the stem through 180".
5. A device as claimed in any one of claims 1 to 3 wherein two channels are formed through the valve body one of said channels communicating at its inner end with the outlet port of the valve and the other of said channels being located so that when a recess is aligned with the inner end of the channel, the recess is isolated from both the inlet and outlet ports of the valve.
6. A device as claimed in claim 5 wherein the one of said channels is connected to a source of a conveying fluid and the other of said channels is connected to a region of low pressure.
7. A metering device substantially as hereinbefore described with particular reference to the drawings.
8. A process for metering a powdered solid or a concentrated suspension of a powdered solid in an inert liquid wherein the metering device of any one of claims 1 to 7 is used.
9. A process as claimed in claim 8 wherein an olefin polymerisation catalyst, or a component of such a catalyst, is metered.
10. A process as claimed in claim 9 wherein the metering device of claim 6 is used and the conveying fluid is liquid propylene or gaseous ethylene.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB7847173A GB2024158A (en) | 1977-09-08 | 1978-12-05 | Metering device |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB3756077 | 1977-09-08 | ||
| GB7847173A GB2024158A (en) | 1977-09-08 | 1978-12-05 | Metering device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB2024158A true GB2024158A (en) | 1980-01-09 |
Family
ID=26263498
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB7847173A Withdrawn GB2024158A (en) | 1977-09-08 | 1978-12-05 | Metering device |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2024158A (en) |
Cited By (18)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3228345A1 (en) * | 1982-07-29 | 1984-02-02 | Günter 8882 Lauingen Stein | CONTROL DEVICE FOR LIQUID OR GASEOUS MEDIUM |
| GB2134487A (en) * | 1983-02-04 | 1984-08-15 | Ideal Standard | Dosing of fluids |
| GB2135655A (en) * | 1983-02-22 | 1984-09-05 | Kamyr Inc | Dry feeder |
| DE3346783A1 (en) * | 1983-12-23 | 1985-07-11 | Pfister Gmbh, 8900 Augsburg | VOLUMETRIC DOSING DEVICE |
| FR2664692A1 (en) * | 1990-07-13 | 1992-01-17 | Schildknecht Bernard | DEVICE FOR VOLUMETRIC FLUID DOSING. |
| US5161717A (en) * | 1991-01-08 | 1992-11-10 | Sematech, Inc. | Spin casting of silicon wafers |
| US5171541A (en) * | 1986-06-16 | 1992-12-15 | Bp Chemicals Limited | Fluidized bed discharge process |
| WO1994005979A1 (en) * | 1987-03-05 | 1994-03-17 | Sigmon James W | Improved vaneless rotor airlock valve |
| EP0646776A1 (en) * | 1993-10-01 | 1995-04-05 | Wilhelm A. Keller | A metering device for fluids |
| US5405062A (en) * | 1992-09-09 | 1995-04-11 | Nestec S.A. | Rotary product supply and discharge distributors |
| US5405059A (en) * | 1992-11-21 | 1995-04-11 | Nestec S.A. | Rotary filling apparatus |
| US5823401A (en) * | 1996-02-05 | 1998-10-20 | Zgoda; Roy F. | Sampling and dispensing ball-valve |
| US5850946A (en) * | 1994-10-03 | 1998-12-22 | Wilhelm A. Keller | Metering device |
| EP1186308A2 (en) * | 2000-09-08 | 2002-03-13 | Ethicon Inc. | Metering valve to deliver liquid |
| GB2404372A (en) * | 2003-06-25 | 2005-02-02 | Hygiene Technik Inc | Ball-valve dispenser with resiliently biased two-part housing |
| DE102007057415A1 (en) * | 2007-11-27 | 2009-06-04 | Sig Technology Ag | Fluid product e.g. fruit yogurt, sampling valve, has valve plug pivotably arranged at housing, and transportation pockets with openings provided in valve plug, where openings point radially outwards |
| NL2009170C2 (en) * | 2012-07-11 | 2014-01-14 | Stichting Energie | Feed valve. |
| ITLU20120011A1 (en) * | 2012-07-31 | 2014-02-01 | Valvengineering Srl | BALL VALVE MODIFIED TO ALLOW THE DETERMINATION OF PRODUCTS BETWEEN CONTAINERS WITH PRESSURE DIFFERENTIALS |
-
1978
- 1978-12-05 GB GB7847173A patent/GB2024158A/en not_active Withdrawn
Cited By (27)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3228345A1 (en) * | 1982-07-29 | 1984-02-02 | Günter 8882 Lauingen Stein | CONTROL DEVICE FOR LIQUID OR GASEOUS MEDIUM |
| GB2134487A (en) * | 1983-02-04 | 1984-08-15 | Ideal Standard | Dosing of fluids |
| FR2544102A1 (en) * | 1983-02-04 | 1984-10-12 | Ideal Standard | DOSING APPARATUS FOR FLUIDS |
| GB2135655A (en) * | 1983-02-22 | 1984-09-05 | Kamyr Inc | Dry feeder |
| US4508473A (en) * | 1983-02-22 | 1985-04-02 | Kamyr, Inc. | Simple dry feeder |
| DE3346783A1 (en) * | 1983-12-23 | 1985-07-11 | Pfister Gmbh, 8900 Augsburg | VOLUMETRIC DOSING DEVICE |
| US5171541A (en) * | 1986-06-16 | 1992-12-15 | Bp Chemicals Limited | Fluidized bed discharge process |
| WO1994005979A1 (en) * | 1987-03-05 | 1994-03-17 | Sigmon James W | Improved vaneless rotor airlock valve |
| FR2664692A1 (en) * | 1990-07-13 | 1992-01-17 | Schildknecht Bernard | DEVICE FOR VOLUMETRIC FLUID DOSING. |
| US5161717A (en) * | 1991-01-08 | 1992-11-10 | Sematech, Inc. | Spin casting of silicon wafers |
| US5405062A (en) * | 1992-09-09 | 1995-04-11 | Nestec S.A. | Rotary product supply and discharge distributors |
| US5405059A (en) * | 1992-11-21 | 1995-04-11 | Nestec S.A. | Rotary filling apparatus |
| EP0646776A1 (en) * | 1993-10-01 | 1995-04-05 | Wilhelm A. Keller | A metering device for fluids |
| US5547110A (en) * | 1993-10-01 | 1996-08-20 | Wilhelm A. Keller | Metering device for fluids |
| US5850946A (en) * | 1994-10-03 | 1998-12-22 | Wilhelm A. Keller | Metering device |
| US6059148A (en) * | 1994-10-03 | 2000-05-09 | Wilhelm A. Keller | Metering device |
| US5823401A (en) * | 1996-02-05 | 1998-10-20 | Zgoda; Roy F. | Sampling and dispensing ball-valve |
| EP1186308A3 (en) * | 2000-09-08 | 2002-03-20 | Ethicon Inc. | Metering valve to deliver liquid |
| EP1186308A2 (en) * | 2000-09-08 | 2002-03-13 | Ethicon Inc. | Metering valve to deliver liquid |
| US6699434B1 (en) | 2000-09-08 | 2004-03-02 | Ethicon, Inc. | Metering valve to deliver liquid |
| GB2404372A (en) * | 2003-06-25 | 2005-02-02 | Hygiene Technik Inc | Ball-valve dispenser with resiliently biased two-part housing |
| GB2404372B (en) * | 2003-06-25 | 2006-03-08 | Hygiene Technik Inc | Metering ball-valve with biased housing |
| DE102007057415A1 (en) * | 2007-11-27 | 2009-06-04 | Sig Technology Ag | Fluid product e.g. fruit yogurt, sampling valve, has valve plug pivotably arranged at housing, and transportation pockets with openings provided in valve plug, where openings point radially outwards |
| DE102007057415B4 (en) * | 2007-11-27 | 2010-01-28 | Sig Technology Ag | Use of a valve for sampling of a one-piece, flowable product |
| NL2009170C2 (en) * | 2012-07-11 | 2014-01-14 | Stichting Energie | Feed valve. |
| WO2014011038A1 (en) * | 2012-07-11 | 2014-01-16 | Stichting Energieonderzoek Centrum Nederland | Feed valve |
| ITLU20120011A1 (en) * | 2012-07-31 | 2014-02-01 | Valvengineering Srl | BALL VALVE MODIFIED TO ALLOW THE DETERMINATION OF PRODUCTS BETWEEN CONTAINERS WITH PRESSURE DIFFERENTIALS |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |