Pressure-limiting valve

Abstract

A pressure-limiting valve for use in a gas line conveying a gas that includes aerosols. The pressure-limiting valve has a movable valve body, a valve seat, and a compressible coalescing medium placed therebetween. The valve body has passages and nozzle openings and the valve seat has through-holes. In the closed position, the valve functions in separator mode and in the fully open position, in impactor mode. The pressure-limiting valve according to the invention provides a more sensitive response to varying flow conditions, due to deviating surface profiles of the valve seat and coalescing medium, which provide intermediate stages of separator and impactor modes as a function of the volume of flow.

Claims

1. A pressure-limiting valve for use in a gas line carrying aerosols, the pressure-limiting valve comprising: a valve body having one or more body openings; a valve seat having a nozzle arrangement that includes a plurality of nozzle openings; and a coalescing medium made of compressible material and provided between the valve body and the valve seat; wherein the valve body is urged by a force device to a closed position and is movable between the closed position, in which the valve body holds the coalescing medium up against the valve seat, the flow of gas then being through the nozzle openings, the coalescing medium, and through the openings in the valve body, and a fully open position in which all the nozzle openings are in flow connection with a gap that is created between the coalescing medium and the valve seat; and wherein a surface profile of a coalescing medium surface and a surface profile of a valve seat surface are offset from one another, the surface profile of the valve seat having a stepped construction such that as the valve body moves toward the open position the distance of the valve body and the coalescing medium from the valve seat gradually increases, thereby creating an increasing large-area gap between the coalescing medium and the valve seat.

2. The pressure limiting valve of claim 1, wherein, an inner region of the valve seat surface and an inner region of the coalescing medium surface are closer to each other than at outer regions of the respective surfaces.

3. Pressure-limiting valve according to claim 2, wherein the valve seat surface facing the coalescing medium curves concavely from a central region to the edge of the valve seat.

4. Pressure-limiting valve according to claim 2, wherein the valve seat surface curves convexly from a central region to the edge of the valve seat.

5. Pressure-limiting valve according to claim 2, wherein the valve seat surface extends in a straight line from a central region to the edge of the valve seat.

6. The pressure-limiting valve according to claim 2, wherein the valve seat surface extends in a spiral from a central region to the edge of the valve seat.

7. The pressure-limiting valve according to claim 1, wherein the coalescing medium is constructed as a flat disc.

8. The pressure-limiting valve according to claim 1, wherein a profile of the coalescing medium surface has a three-dimensional construction.

9. The pressure-limiting valve according to claim 8, wherein the coalescing medium is constructed with a plurality of concentrically arranged, flat disks of varying diameters, and wherein a central region of the three-dimensional construction is closer to the valve seat than at the edge.

10. The pressure-limiting valve of claim 1, wherein the coalescing medium contains a multitude of fibers.

11. The pressure-limiting valve of claim 1, wherein the coalescing medium is constructed from a non-woven material.

12. An oil separator comprising: a pressure-limiting valve that has a valve body having one or more body openings, a valve seat having a nozzle arrangement that includes a plurality of nozzle openings, and a coalescing medium made of compressible material and provided between the valve body and the valve seat; wherein the valve body is urged by a force device to a closed position and is movable between the closed position, in which the valve body holds the coalescing medium up against the valve seat, the flow of gas then being through the nozzle openings, the coalescing medium, and through the openings in the valve body, and a fully open position in which all the nozzle openings are in flow connection with a gap that is created between the coalescing medium and the valve seat; and wherein a surface profile of a coalescing medium surface and a surface profile of a valve seat surface are offset from one another, the surface profile of the valve seat having a stepped construction such that as the valve body moves toward the open position the distance of the valve body and the coalescing medium from the valve seat gradually increases, thereby creating an increasing large-area gap between the coalescing medium and the valve seat.

13. A pressure-limiting valve for regulating a flow of gas containing aerosols, the pressure-limiting valve comprising: a valve seat component that includes a nozzle arrangement having a plurality of radially spaced-apart nozzle openings and a valve seat surface; a valve body that has a valve plate with plate openings, the valve body being urged toward a closed position and movable toward an open position when pressure from the flow of gas increases; and a coalescing medium arranged on the valve plate, the coalescing medium made of a compressible material and having a coalescing medium surface that faces the valve seat surface; wherein the valve seat surface has a surface profile that is not shaped complementary to a profile of the coalescing medium surface, such that, when the valve plate begins to move away from the valve seat, a gap having a gap length that is initially created at an outer region of the valve seat continues to extend toward an inner region as the valve plate continues to move farther from the valve seat, so that, depending on a distance of the valve plate from the valve seat, the radially spaced-apart nozzle openings open successively into the gap, first from the outer region and progressing successively toward the inner region.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The present invention is described with reference to the accompanying drawings. In the drawings, like reference numbers indicate identical or functionally similar elements.

(2) FIG. 1 is a cross-sectional view through a first embodiment of a pressure-limiting valve according to the invention in its closed position.

(3) FIG. 2 is a cross-sectional view of the pressure-limiting valve of FIG. 1 in a first intermediate position, illustrating a first gap length.

(4) FIG. 3 is a cross-sectional view of the pressure-limiting valve of FIG. 1 in a second intermediate position, illustrating an increased gap length.

(5) FIG. 4 is a cross-sectional view of the pressure-limiting valve of FIG. 1 in a fully open position, illustrating a maximal gap length.

(6) FIG. 5 is a perspective view of the interior of the valve seat of the pressure-limiting valve of FIGS. 1 to 4.

(7) FIG. 6 is an elevation view of a first embodiment of the valve seat, illustrating a concave profile.

(8) FIG. 7 is an elevation view of a second embodiment of the valve seat, illustrating a convex profile.

(9) FIG. 8 is an elevation view of a third embodiment of the valve seat, illustrating a straight conical profile.

(10) FIG. 9 is an elevation view of a fourth embodiment of the valve seat, illustrating a spiral construction.

(11) FIG. 10 is an elevation view similar to that of FIG. 4, illustrating the pressure-limiting valve in its fully open position and a three-dimensional construction of the coalescing medium, the central portion of which extends close to the center of the valve seat.

DETAILED DESCRIPTION OF THE INVENTION

(12) The present invention will now be described more fully in detail with reference to the accompanying drawings, in which the preferred embodiments of the invention are shown. This invention should not, however, be construed as limited to the embodiments set forth herein; rather, they are provided so that this disclosure will be complete and will fully convey the scope of the invention to those skilled in the art.

(13) FIG. 1 is a cross-sectional view that illustrates a pressure-limiting valve 1 according to the invention. The pressure-limiting valve 1 has a valve body 2 that forms a valve plate 3 and a valve stem 4. A valve spring 5 supports the valve body 2 on a component that is referred to as a seat component 6. The valve spring 5 is a compression spring that applies a force to the valve stem 4 that urges the valve body 2 upwards relative to the seat component 6, i.e., to a closed position.

(14) A coalescing medium 7 is provided on the valve plate 3. This coalescing medium 7 is a flat, round disc, made of a non-woven, compressible material, with a central hole through which the valve stem 4 extends. The force of the valve spring 5 urges the valve plate 3 upward, thereby pressing the coalescing medium 7 against the seat component 6 and causing the coalescing medium to compress. In this illustration, the coalescing medium 7 is shown essentially in a decompressed state. Elements of the seat component 6, however, press against the coalescing medium 7 and actually cause compression at those locations and this compression is indicated in FIG. 1 where elements of the seat component 6 are shown penetrating into the coalescing medium 7.

(15) The coalescing medium 7 is shown making contact against the seat component 6 along a surface that is referred to as a valve seat 8. In a radially outer region, the coalescing medium 7 lies uncompressed against the valve seat 8, whereas the remaining surfaces of the valve seat 8 toward a radially inner region compress the coalescing medium 7 lying against the valve seat 8 to varying degrees, the areas of compression the corresponding to the penetrations shown in FIG. 1.

(16) A plurality of individual nozzle openings 9 are provided in the seat component 6. The nozzle openings 9 and their corresponding passages are separated or delimited from one another by webs 11 of the seat component 6 and are collectively referred to as a nozzle arrangement 10.

(17) Flow-through passages or openings 15 are also provided in the valve plate 3. These openings 15 provide exit flow paths through the valve plate 3 for the gas that flows through the nozzle arrangement 10 and into the coalescing medium 7.

(18) FIG. 1 shows the pressure-limiting valve 1 in its closed position, in which the valve plate 3 along with the coalescing medium 7 is pressed up against the valve seat 8, with all of the nozzle openings 9 of the nozzle arrangement 10 covered by the coalescing medium 7. This closed position represents a strictly separator mode of operation of the pressure-limiting valve 1, wherein the entire stream of gas flows through the coalescence medium 7, where the aerosols entrained in the gas flow are separated out.

(19) Pressure from the gas flow exerts a force on the valve body 2 in a direction opposite to the action of the valve spring 5, and a sufficiently strong flow of gas opens the pressure limiting valve 1 against the action of the valve spring 5. At low volume flows, however, the valve body 2 remains in the closed position shown in FIG. 1. Due to the fact that the coalescing medium 7 is compressed by the valve seat 8 in the area of the nozzle arrangement 10, the spacing of the fibers within the non-woven fabric that make up the coalescing medium 7 is very dense at low volumes of flow.

(20) FIG. 2 shows the pressure-limiting valve 1 of FIG. 1 in an intermediate position in which an increase in volume of flow has forced the valve body 2 to move counter to the action of the valve spring 5 partially away from its closed position and in the direction of an open position of the valve 1. As shown in this figure, the valve body 2 has been moved away from the valve seat 8 just enough to move the upper surface of the coalescing medium 7 away from the valve seat 8 in the radially outer region so that the coalescing medium 7 no longer makes contact against the valve seat 8, resulting in a gap 12 in this outer region, the gap having a gap length that is designated here in this illustration as gap length 12A. A first nozzle opening 9A now opens into the gap 12, instead of into the coalescing medium 7. At the same time, the radially inner region of the coalescing medium 7 remains in contact against the corresponding region of the valve seat 8 and remains compressed to varying degrees by the elements of the valve seat 8, as the illustrated penetrations show.

(21) FIG. 3 shows a further intermediate state of the pressure-limiting valve 1, resulting from a further increase in the volume of flow through the pressure-limiting valve 1. In this intermediate stage, the valve plate 3 is moved again a bit farther away from the valve seat 8, thereby increasing the gap width of the gap 12, as well as the gap length, designated here as 12B, and as a result now a second nozzle opening 9B also opens into the gap 12, and only a radially inner third nozzle opening 9C of the nozzle arrangement 10 opens into the coalescing medium 7.

(22) The gap 12, with the gap lengths 12A and 12B, result in the respective nozzle openings 9A and 9B being in flow connection with the gap 12, with the consequence that the gas flowing through these nozzle openings 9A and 9B goes through a change in direction of flow, and, instead of flowing straight ahead into the coalescing medium 7, the gas flows through the gap 12 along the surface of the coalescing medium 7. In these intermediate stages, the pressure-limiting valve 1 operates in impactor mode in the radially outer region and in separator mode in the radially radially inner region.

(23) FIG. 4 shows the pressure-limiting valve 1 in its fully open position, i.e., the valve plate 3 and the coalescing medium 7 are moved away from the valve seat 8 to such an extent that the gap length, designated in this illustration as 12C, is at its maximum size and all of the nozzle openings 9A, 9B, and 9C of the nozzle arrangement 10 open into the gap 12. The coalescing medium 7 remains in contact with the valve seat 8 in the radially innermost region, but this has no effect on the flow-through ability of the nozzle arrangement 10, because there are no nozzle openings 9 in this innermost region.

(24) FIG. 5 is a perspective view of the interior of the seat component 6 with annular, stepped individual sections of the valve seat 8 and webs 11, which extend between the nozzle openings 9 of the nozzle arrangement 10.

(25) FIGS. 6-9 illustrate side plane views of various profiles of the valve seat 8 on the valve component 6. In these illustrations, the outer collar of the seat component 6 that is shown in the previous FIGS. 1-5 is not shown. Common to all of the various valve seat profiles is the fact that the radially inner region of the valve seat 8 extends closer to the valve plate 3 and the coalescing medium 7 than the region that is located farther away from the inner region.

(26) FIG. 6 shows a first profile of the radially inner region of a seat component 6, which extends in a concave curved profile. FIG. 7 shows a second profile of the radially inner region of the valve seat component 6, which extends in a convex curved profile, that is to say, in an outwardly bulging curvature. FIG. 8 shows a third profile that is conical, with the profile extending outward from the center in a straight line. FIG. 9 shows a fourth profile of the radially inner region of the seat component 6 that is formed as a spiral, the nozzle openings 9 situated between ridges of the spiral.

(27) FIG. 10 is a cross-sectional view of a second embodiment of the pressure-limiting valve 1 according to the invention, showing the pressure-limiting valve 1 in its fully open position. In this embodiment, the surface of the valve seat 8 facing the coalescing medium 7 has a planar construction and the coalescing medium 7 has a three-dimensional, stepped construction. This stepped construction is achieved by stacking differently sized flat disks 14 one above the other. The disks are made from compressible material, such as was described above with reference to the coalescing medium 7. In the embodiment shown, the materials used for the disks are of different thicknesses. This is only by way of example. It is, of course, possible to use disks 14 of the same material thickness, which is particularly advantageous, as they can be cut from the same sheet of material.

(28) In the embodiment of FIG. 10 and also in the other embodiments, the fiber spacing within the coalescing medium 7 in the decompressed state is greater than in the compressed state. The difference in fiber spacing is, however, not a disadvantage for the performance of the coalescing medium 7 in separator mode, because, when the volume of flow is high, those portions of the gas stream that are not deflected into the gap 12, but instead flow into the coalescing medium 7, enter at such a high flow rate that, under these conditions, the separator efficiency of the coalescing medium 7 remains high.

(29) It is understood that the embodiments described herein are merely illustrative of the present invention. Variations in the construction of the pressure-limiting valve may be contemplated by one skilled in the art without limiting the intended scope of the invention herein disclosed and as defined by the following claims.