1-7. (canceled)
8. A multilayer catalyst for the oxidation of naphthalene or o xylenenaphthalene mixtures to phthalic anhydride, which comprises at least three catalyst layers which each comprise vanadium oxide and titanium dioxide and have alkali metal contents selected so that
a) the alkali metal content of one catalyst layer A is the highest,
b) a catalyst layer Z which follows the catalyst layer A in the flow direction has an alkali metal content of from 0 to 10% of the alkali metal content of the catalyst layer A and
c) the catalyst layers located between the catalyst layers A and Z have an alkali metal content of from 30 to 90% of the alkali metal content of the catalyst layer A, with the alkali metal content of each catalyst layer being higher than the alkali metal content of the next catalyst layer in the flow direction.
9. The multilayer catalyst according to claim 8 having four layers, wherein the alkali metal contents of the catalyst layers are selected so that
a) the alkali metal content of one catalyst layer A is the highest,
b) a catalyst layer B which follows the catalyst layer A in the flow direction has an alkali metal content of from 60 to 90% of the alkali metal content of the catalyst layer A,
c) a catalyst layer C which follows the catalyst layer B in the flow direction has an alkali metal content of from 30 to 59% of the alkali metal content of the catalyst layer A,
d) a catalyst layer Z which follows the catalyst layer C in the flow direction has an alkali metal content of from 0 to 10% of the alkali metal content of the catalyst layer A.
10. The multilayer catalyst according to claim 8, wherein the bed length of the catalyst layer A is in the range from 10 to 50% of the total catalyst fill height in the reactor.
11. The multilayer catalyst according to claim 9, wherein the bed length of the catalyst layer A is in the range from 10 to 50% of the total catalyst fill height in the reactor.
12. A process for the oxidation of naphthalene or o xylenenaphthalene mixtures to phthalic anhydride which comprises utilizing a multilayer catalyst comprising at least three catalyst layers which each comprise vanadium oxide and titanium dioxide and have alkali metal contents selected so that
a) the alkali metal content of one catalyst layer A is the highest,
b) a catalyst layer Z which follows the catalyst layer A in the flow direction has an alkali metal content of from 0 to 10% of the alkali metal content of the catalyst layer A and
c) the catalyst layers located between the catalyst layers A and Z have an alkali metal content of from 30 to 90% of the alkali metal content of the catalyst layer A, with the alkali metal content of each catalyst layer being higher than the alkali metal content of the next catalyst layer in the flow direction.
13. The process according to claim 12 wherein the catalyst is a four-layer catalyst, wherein the alkali metal contents of the catalyst layers are selected so that
a) the alkali metal content of one catalyst layer A is the highest,
b) a catalyst layer B which follows the catalyst layer A in the flow direction has an alkali metal content of from 60 to 90% of the alkali metal content of the catalyst layer A,
c) a catalyst layer C which follows the catalyst layer B in the flow direction has an alkali metal content of from 30 to 59% of the alkali metal content of the catalyst layer A,
d) a catalyst layer Z which follows the catalyst layer C in the flow direction has an alkali metal content of from 0 to 10% of the alkali metal content of the catalyst layer A.
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 seed planter for planting seeds in a trench in the ground, the seed planter comprising a seed hopper for receiving round and cylindrically shaped seeds, an upright endless belt supported for movement along a path and including an upward portion adapted for upward movement through the hopper and a downward portion adapted for movement downwardly towards the ground, a plurality of vertically offset cups attached to the endless belt for movement along the path, the cups opening upwardly into the hopper on the upward portion and opening downwardly to release the seeds towards the ground on the downward portion, adjacent cups each adapted to receive an individual seed as the cups moves upwardly with the belt through the hopper, the improvement comprising:
a seed-intercepting indexing pocket facing one of the adjacent cups, the indexing pocket orienting the seed released from the adjacent cup relative to the trench.
2. The seed planter as set forth in claim 1 wherein the indexing pocket includes a concave partial cylindrical portion supporting a cylindrical seed having a length to diameter ratio of approximately 3 to 1 or less.
3. The seed planter as set forth in claim 2 wherein the cups have an upwardly concave surface for supporting the cylindrical seed as the cups move upwardly through the hopper.
4. The seed planter as set forth in claim 1 wherein the hopper includes a hopper floor angled towards the belt and a seed pressure head reducer projecting upwardly from the floor adjacent the path.
5. The seed planter as set forth in claim 4 wherein each of the cups include a leading edge projecting towards the floor and the seed pressure head reducer includes an upright wall adjacent the leading edge.
6. The seed planter as set forth in claim 4 wherein the belt supports at least two transversely spaced columns of the vertically offset cups and the pressure head reducer is located between the spaced columns.
7. The seed planter as set forth in claim 1 wherein the cups include undersides, and wherein the seed-intercepting indexing pockets are located on the undersides.
8. A seed planter for planting seeds in a trench in the ground, the seed planter comprising a seed hopper for receiving the seeds, an upright endless belt supported for movement along a path and including an upward portion adapted for upward movement through the hopper and a downward portion adapted for movement downwardly towards the ground, a plurality of vertically offset cups attached to the endless belt for movement along the path, the cups including a seed pickup surface concave upwardly on the upward portion, the cups opening downwardly to releases the seeds towards the ground on the downward portion, the upward movement of the upward portion singulating the seeds in the cups, the improvement comprising:
the cups having an underside including a seed-intercepting orientation pocket opening upwardly towards an upwardly adjacent cup on the downward portion, the pocket orienting the seed released from the upwardly adjacent cup relative to the trench.
9. The seed planter as set forth in claim 8 wherein the pickup surface includes a concave partial cylindrical portion supporting a cylindrical seed having a length to diameter ratio of approximately 3 to 1 or less.
10. The seed planter as set forth in claim 9 wherein the orientation pocket comprises a cylindrically-shaped object receiving portion for orienting a cylindrical seed having a length to diameter ratio of 3 to 1 or less.
11. The seed planter as set forth in claim 8 wherein the hopper includes a hopper floor angled towards the belt and a seed pressure head reducer projecting upwardly from the hopper floor adjacent the path.
12. The seed planter as set forth in claim 11 wherein each of the cups include a leading edge projecting towards the floor and the seed pressure head reducer includes an upright wall adjacent the leading edge.
13. The seed planter as set forth in claim 11 wherein the belt supports at least two transversely spaced columns of the vertically offset cups and the pressure head reducer is located between two of the columns of vertically offset cups.
14. A seed planter for planting seeds in a trench in the ground, the seed planter comprising a seed hopper for receiving the seeds, an upright endless belt supported for movement along a path and including an upward portion adapted for upward movement through the hopper and a downward portion adapted for movement downwardly towards the ground, a plurality of vertically offset cups attached to the endless belt for movement along the path, the cups including a seed pickup surface concave upwardly on the upward portion, the hopper including an angled floor directing the seed by gravity towards the seed pickup surfaces of the cups, the cups opening downwardly to releases the seeds towards the ground on the downward portion, the upward movement of the upward portion singulating the seeds in the cups, the improvement comprising:
a seed pressure head reducer projecting upwardly from the floor adjacent the cups, pressure head reducer defining a seed path leading into the seed pickup surface and preventing binding of the seeds.
15. The seed planter as set forth in claim 14 wherein the pressure head reducer comprises a triangular shaped cone member supported above the angled floor.
16. The seed planter as set forth in claim 14 wherein the vertically offset cups comprise upright columns of cups for side-by-side movement of the cups along the path, and wherein the pressure head reducer is located between the columns to prevent movement of seed from one column to the other.
17. The seed planter as set forth in claim 16 wherein the upright columns of cups comprise cylindrical receiving portions for receiving cylindrically shaped seeds having a length to diameter ratio of 3 to 1 or less.
18. The seed planter as set forth in claim 17 wherein the cylindrical receiving portions are located on the seed pickup surface and on a side of the cup opposite the seed pickup surface for orienting cylindrical seeds as the seeds fall from the next adjacent cups on the downward portion of the endless belt.
19. A seed planter for planting seeds in a trench in the ground, the seed planter comprising a seed hopper for receiving seeds, an upright endless belt supported for movement along a path and including an upward portion adapted for upward movement through the hopper and a downward portion adapted for movement downwardly towards the ground, a plurality of vertically offset cups attached to the endless belt for movement along the path, the cups opening upwardly into the hopper on the upward portion and opening downwardly to releases the seeds towards the ground on the downward portion, adjacent cups each adapted to receive an individual seed as the cups moves upwardly with the belt through the hopper, the improvement comprising:
the cups having cylindrical seed receiving and orienting portions, the cylindrical seed receiving and orienting portions lying on generally partial cylinders having length to diameter ratios on the order of 3 to 1.
20. The planter as set forth in claim 19 wherein the receiving and orienting portions are located on opposite sides of each of the cups to define an upwardly directed seed pickup concavity on the upward portion of the belt and an upwardly directed seed orientation cavity on the downward portion of the belt.
21. The planter as set forth in claim 19 further comprising a seed hopper floor angled downwardly towards the cups and a seed pressure head reducer projecting vertically from the floor adjacent the cups.