1. A pitot-static device comprising first and second pluralities of hollow spokes extending in a radial direction from a central hub,
the hollow interiors of the spokes of the first plurality being connected so as to allow fluid communication therebetween, and at least all but one of the spokes of the first plurality having at least one aperture facing in a first axial direction that is transverse to the radial direction, and
the hollow interiors of the spokes of the second plurality being connected so as to allow fluid communication therebetween, and at least one of the spokes of the second plurality having an aperture at an end portion thereof that faces in the radial direction.
2. The pitot-static device according to claim 1, in which at least all but one of the spokes of the second plurality have an aperture at an end portion thereof that faces in the radial direction.
3. The pitot-static device according to claim 1, in which at least one of the spokes of the first plurality has an aperture at an end thereof sealed against fluid communication.
4. The pitot-static device according to claim 3, in which at least all but one of the spokes of the first plurality have an aperture at an end thereof sealed against fluid communication.
5. A The pitot-static device according to claim 1, further comprising a handle for manual support.
6. A pitot-static device, comprising:
a central hub;
a first plurality of hollow spokes extending in a radial direction from the central hub;
a second plurality of hollow spokes extending in a radial direction from the central hub;
the hollow interiors of the spokes of the first plurality being connected so as to allow fluid communication therebetween, and at least all but one of the spokes of the first plurality having at least one aperture facing in a first axial direction that is transverse to the radial direction;
the hollow interiors of the spokes of the second plurality being connected so as to allow fluid communication therebetween, and at least all but one of the spokes of the second plurality having at least one aperture; and
a handle for manual support.
7. The pitot-static device according to 6, further comprising a ring around the central hub, the spokes extending from the central hub to an inner face of the ring.
8. The pitot-static device according to claim 7, in which at least the spokes of the second plurality each have an aperture at an end thereof, the end apertures extending through the ring.
9. The pitot-static device according to claim 7, in which the handle is attached to the ring.
10. The pitot-static device according to claim 6, further comprising:
a conduit extending from the central hub to the handle.
11. The pitot-static device according to claim 10, in which the conduit is free from apertures between the central hub and the handle.
12. The pitot-static device according to claim 6, in which the handle includes a connector for connection to external fluid conduits.
13. A pitot-static device, comprising a hub from which extends a plurality of spokes integrally moulded with a part of the hub, each spoke having a hollow interior that is in fluid communication with an interior space of the hub and at least one aperture to sense a fluid pressure, the hub being formed of a concave section and a cap attached thereto so as to close the concave section and define the interior space.
14. A pitot-static device, comprising a hub from which extend first and second pluralities of hollow spokes,
the spokes of the first plurality being connected via a first internal space within the hub so as to allow fluid communication between the hollow interiors thereof, and at least all but one of the spokes of the first plurality having at least one aperture facing in a first axial direction that is transverse to the spokes of the first plurality,
the spokes of the second plurality being connected via a second internal space within the hub so as to allow fluid communication between the hollow interiors thereof, and at least all but one of the spokes of the second plurality having at least one aperture,
wherein the hub is defined by at least three parts, comprising two concave sections being
moulded integrally with, respectively, the spokes of the first and the second pluralities, and
at least one cap connected to the concave sections, thereby to close the concave section and define the internal spaces.
15. The pitot-static device according to claim 14, in which there are two caps, one connected to each concave section.
16. The pitot-static device according to claim 14, in which an o-ring is interposed between the or each cap and each concave part.
17. A pitot-static device, comprising first and second pluralities of hollow spokes,
the spokes of the first plurality being connected so as to allow fluid communication between the hollow interiors thereof, and all but one spoke of the first plurality having at least one aperture facing in a first axial direction that is transverse to the spokes of the first plurality,
the spokes of the second plurality being connected so as to allow fluid communication between the hollow interiors thereof, and all but one spoke of the second plurality having at least one aperture,
wherein the spokes extend radially from a central hub, the hollow interiors of the spokes of the first plurality being connected via a first interior space within the central hub, the hollow interiors of the spokes of the second plurality being connected via a second interior space within the central hub, and the one spoke of each plurality is free from apertures other than at an end thereof.
18. The pitot-static device according to claim 17, in which the spokes of the second plurality include apertures facing in a second axial direction that is opposed to the first axial direction.
19. The pitot-static device according to claim 14, in which at least all but one of the second plurality of spokes each have an aperture at the end thereof.
20. The pitot-static device according to claim 14, in which at least all but one of the spokes of the first plurality have an aperture at an end thereof, the end apertures being sealed against fluid communication.
21. A pitot-static device, comprising first and second pluralities of hollow spokes, the hollow interiors of the spokes of the first plurality being connected so as to allow fluid communication therebetween and each spoke of the first plurality having at least one aperture facing in a first axial direction that is transverse to the spokes of the first plurality, the hollow interiors of the spokes of the second plurality being connected so as to allow fluid communication therebetween and each spoke of the second plurality having at least one aperture facing in a second axial direction that is opposed to the first axial direction.
22. The pitot-static device according to claim 21, in which the spokes extend radially from a central hub.
23. The pitot-static device according to claim 22, in which the hollow interiors of the spokes of at least one of the pluralities are connected via an interior space within the central hub.
24. The pitot-static device according to claim 22, in which the spokes of both the first and second pluralities extend from a single central hub.
25. The pitot-static device according to claim 23, in which the spokes of both the first and second pluralities extend from a single central hub having a first interior space to allow fluid communication between the spokes of the first plurality and a second interior space to allow separate fluid communication between the spokes of the second plurality.
26. The pitot-static device according to a claim 21, in which the second plurality of spokes each have an aperture at the end thereof.
27. The pitot-static device according to claim 26, in which the spokes of the first plurality each have an aperture at an end thereof, the end apertures being sealed against fluid communication.
28. A pitot-static device, comprising a plurality of hollow spokes extending in a first direction, wherein the hollow interiors of the spokes are connected so as to allow fluid communication therebetween, and at least all but one of the spokes has at least one aperture facing in a second, axial direction that is transverse to the first direction.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A ring catalyst for preparing acrolein and acrylic acid,
including a mixture of an catalytic active ingredient including at least molybdenum (Mo) and bismuth (Bi), and an inorganic fiber, and
having a ring shape, and
satisfying the following Relational Equation 1:
0.1\u22662Lf(De\u2212Di)<0.2\u2003\u2003Relational Equation 1
wherein, in said Relational Equation 1, Lf is the number average length of the inorganic fiber, De is the external diameter of the ring catalyst, and Di is the internal diameter of the ring catalyst.
2. The ring catalyst according to claim 1, satisfying the following Relational Equation 2:
0.2\u2266LcDe\u22661.5\u2003\u2003Relational Equation 2
wherein, in said Relational Equation 2, Lc is the longitudinal length of the ring catalyst, and De is the external diameter of the ring catalyst.
3. The ring catalyst according to claim 2, wherein the ring catalyst has at least two shapes having different LcDe.
4. The ring catalyst according to claim 3, wherein the ring catalyst includes 2 kinds or more of catalysts of the first type having LcDe of 0.2 to 1 and the second type having LcDe of 0.6 to 1.5.
5. The ring catalyst according to claim 1, wherein the catalytic active ingredient is represented by the following Chemical Formula 1:
Moa Bib Ac Bd Ce Of\u2003\u2003Chemical Formula 1
wherein, in Chemical Formula 1,
Mo is molybdenum; Bi is bismuth; A is one or more elements selected from the group consisting of Fe, Zn, Mn, Nb, and Te; B is one or more elements selected from the group consisting of Co, Rh, and Ni; C is one or more elements selected from the group consisting of Na, K, Li, Cs, Ta, Ca, Rb, and Mg; O is oxygen; and
a, b, c, d, e, and f are atomic ratios of each element, wherein b is 0.1 to 10, c is 0.1 to 10, d is 0.1 to 15, e is 0.001 to 10, and f is a number determined according to the oxidation state of each element, when a=12.
6. The ring catalyst according to claim 1, wherein the inorganic fiber is one or more fibers selected from the group consisting of glass fiber, silica fiber, alumina fiber, and silica-alumina fiber.
7. The ring catalyst according to claim 1, wherein the inorganic fiber a the number average length of 2 mm or less and a number average diameter of 2 to 40 \u03bcm.
8. The ring catalyst according to claim 1, wherein the content of the inorganic fiber is 2 to 15 parts by weight per 100 parts by weight of the active ingredient.
9. A preparation method of acrolein and acrylic acid, including the step of
carrying out a catalytic vapor-phase oxidation reaction of one or more raw materials selected from the group consisting of propylene, isobutylene, and tert-butanol, and molecular oxygen, in the presence of the ring catalyst according to claim 1.
10. The preparation method according to claim 9, wherein the catalytic vapor-phase oxidation reaction is carried out in a multi-tubular fixed bed reactor in which the ring catalyst is packed.
11. The preparation method according to claim 9, wherein the ring catalyst satisfies the following Relational Equation 2:
0.2\u2266LcDe\u22661.5\u2003\u2003Relational Equation 2
wherein, in said Relational Equation 2, Lc is the longitudinal length of the ring catalyst, and De is the external diameter of the ring catalyst.
12. The preparation method according to claim 10, wherein the ring catalyst is packed in the reactor to form at least two layers having different LcDe, and said LcDe decreases from the raw material inlet side to the product outlet side of the reactor.