U.S. patent application number 10/057655 was filed with the patent office on 2002-05-30 for process and device for pressurizing flowable reaction components.
Invention is credited to Raffel, Reiner, Sulzbach, Hans-Michael.
Application Number | 20020063354 10/057655 |
Document ID | / |
Family ID | 7639833 |
Filed Date | 2002-05-30 |
United States Patent
Application |
20020063354 |
Kind Code |
A1 |
Sulzbach, Hans-Michael ; et
al. |
May 30, 2002 |
Process and device for pressurizing flowable reaction
components
Abstract
Flowable reaction components of a reaction mixture which form
solid or foamed material comprising filling material are
transported from a storage container to a high-pressure mixing head
in pressure stages by the use of gear pumps connected in series
without major wear of the gear pumps.
Inventors: |
Sulzbach, Hans-Michael;
(Konigswinter, DE) ; Raffel, Reiner; (Siegburg,
DE) |
Correspondence
Address: |
BAYER CORPORATION
PATENT DEPARTMENT
100 BAYER ROAD
PITTSBURGH
PA
15205
US
|
Family ID: |
7639833 |
Appl. No.: |
10/057655 |
Filed: |
January 23, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10057655 |
Jan 23, 2002 |
|
|
|
09838978 |
Apr 20, 2001 |
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Current U.S.
Class: |
264/40.1 ;
264/241; 264/328.4; 264/328.6; 425/145; 425/543 |
Current CPC
Class: |
B01F 35/7176 20220101;
Y10T 137/86131 20150401; B29C 48/37 20190201; B29B 7/60 20130101;
B01F 35/71 20220101 |
Class at
Publication: |
264/40.1 ;
425/145; 425/543; 264/241; 264/328.4; 264/328.6 |
International
Class: |
B29C 045/00 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 25, 2000 |
DE |
10020162.8 |
Claims
What is claimed is:
1. A process for transporting and pressurizing flowable reaction
components of a reaction mixture from at least one storage
container to at least one mixing head, comprising the steps of: (a)
providing at least a first gear pump, a second gear pump, and a
third gear pump, the first, second and third gear pumps having the
same rotary speed of up to about 800 rpm. (b) connecting the first
gear pump to the second gear pump by a first pipeline then
connecting the second gear pump to the third gear pump by a second
pipeline; (c) transporting the flowable reaction components, at
least one of the flowable reaction components comprising filling
material, to the first gear pump, then through the first pipeline
to the second gear pump, then through the second pipeline to the
third gear pump; and (d) providing pressure on the flowable
reaction components in stages.
2. The process according to claim 1, wherein a first pressure stage
begins at the first gear pump, a second pressure stage begins at
the second gear pump, and a third pressure stage begins at the
third gear pump.
3. The process according to claim 2, wherein the volume surplus of
flowable reaction components at the second pressure stage is about
equal the volume of flowable reaction components lost at the first
pressure stage.
4. The process according to claim 2, wherein the volume surplus of
flowable reaction components at the third pressure stage is about
equal the volume of flowable reaction components lost at the second
pressure stage.
5. The process according to claim 2, wherein the pressure level is
increased at each pressure stage.
6. The process according to claim 5, wherein about an equally large
increase in pressure is provided to the first pressure stage, the
second pressure stage and the third pressure stage.
7. The process according to claim 2, wherein excess flowable
reaction components transported in the first pressure stage channel
downstream from the first pressure stage and are recycled back into
the process upstream from the first pressure stage.
8. The process according to claim 2, wherein excess flowable
reaction components transported in the second pressure stage
channel downstream from the second pressure stage and are recycled
back into the process upstream from the second pressure stage.
9. The process according to claim 2, wherein excess flowable
reaction components transported in the first pressure stage channel
downstream from the first pressure stage and are recycled back into
a storage container.
10. The process according to claim 2, wherein excess flowable
reaction components transported in the second pressure stage
channel downstream from the second pressure stage and are recycled
back into a storage container.
11. A process according to claim 2, wherein the pressure of the
first pressure stage is measured.
12. A process according to claim 2, wherein the pressure of the
second pressure stage is measured.
13. A process according to claim 2, wherein the pressure of the
first pressure stage is adjusted.
14. A process according to claim 2, wherein the pressure of the
second pressure stage is adjusted.
15. A process according to claim 13, wherein the pressure is
adjusted as a function of the measured value of the pressure
generated from the first pressure stage.
16. A process according to claim 14, wherein the pressure is
adjusted as a function of the measured value of the pressure
generated from the second pressure stage.
17. A device for transporting and pressurizing flowable reaction
components of a reaction mixture, at least one of the flowable
reaction components comprising filling material, from at least one
storage container to at least one mixing head, comprising: a first
gear pump, a second gear pump, and a third gear pump, all having
the same rotary speed, the first gear pump being connected to the
second gear pump by a first pipeline, the second gear pump then
being connected to the third gear pump by a second pipeline,
wherein pressure is provided on the flowable reaction components in
stages and, optionally, a line for supplying filling material.
18. A device according to claim 17, wherein there is no line for
supplying filling material.
19. A device according to claim 17, wherein a first pressure stage
begins at the first gear pump, a second pressure stage begins at
the second gear pump, and a third pressure stage begins at the
third gear pump.
20. A device according to claim 17, wherein the first gear pump,
the second gear pump, and the third gear pump are all associated
with a common drive shaft.
21. A device according to claim 19, wherein the pressure level is
increased at each pressure stage.
22. A device according to claim 21, wherein an equally large
increase in pressure is provided to the first pressure stage, the
second pressure stage and the third pressure stage.
23. A device according to claim 19, wherein the volume surplus of
flowable reaction components at the second pressure stage is about
equal the volume of flowable reaction components lost at the first
pressure stage.
24. A device according to claim 19, wherein the volume surplus of
flowable reaction components at the third pressure stage is about
equal the volume of flowable reaction components lost at the second
pressure stage.
25. A device according to claim 17, wherein the first and second
pipelines each comprise a return line.
26. A device according to claim 25, wherein the return line of the
first pipeline is connected to the incoming line for the first gear
pump and the return line of the second pipeline is connected to the
incoming line for the second gear pump.
27. A device according to claim 25, wherein the return line of the
first pipeline is connected to a storage container and the return
line of the second pipeline is connected to a storage
container.
28. A device according to claim 25, wherein the return lines each
comprise at least one throttling element.
29. A device according to claim 28, wherein the throttling element
is adjustable.
30. A device according to claim 28, wherein at least one control
instrument is assigned to the throttling element.
31. A device according to claim 30, wherein at least one pressure
gauge is connected to the control instrument.
32. A device according to claim 31, wherein the pressure gauge is
arranged on the pipeline of a gear pump.
33. A device according to claim 25, wherein at least one
pressure-limiting valve is arranged on the return line.
Description
TECHNICAL FIELD OF THE INVENTION
[0001] The present invention is directed to a process and device
for producing a reaction mixture forming solid material or foamed
material from liquid flowable reaction components, wherein at least
one of the flowable reaction components comprises filling material.
According to the invention, the reaction components are transported
from at least one storage container by pumps and metered under high
pressure into a mixing head.
BACKGROUND OF THE INVENTION
[0002] Reaction components charged with filling material, such as
those used in the manufacture of polyurethane articles, are known
to possess high abrasive properties. As a result (and for economic
reasons), the processing of such filled reaction components are
prohibited in conjunction with particular devices, e.g. high
pressure injection mixheads, requiring injection of the components
(polyol and isocyanate) into the mixing chamber of the mixhead at
pressure of above 100 bar and up to 300 bar.
[0003] Reaction components without filling material can be
delivered using conventional high-speed, high-pressure piston
pumps, subjected to high pressure such as 120 to 250 bar, metered,
and then injected into the mixing chamber of a high-pressure mixing
head. However, delivery of reaction components with filling
material through such piston pumps is not possible. Normally, gear
pumps may be used up to a pressure of about 100 bar at 1.500 to
3.000 rpm.
[0004] In producing certain articles, the high-pressure intermixing
of reaction components charged with filling materials is
indispensable. Even though wear by virtue of the abrasive filling
materials can never be entirely eliminated, slow-running
piston-type metering instruments or plunger pumps have been
employed with success. However, such instruments have the
disadvantage of a large overall height, with all the related
disadvantages of maintenance. Additionally, the structure of such
instruments is very elaborate and, therefore, expensive.
[0005] For the foregoing reasons, it would be desirable to develop
a process and device for pressurizing to high pressure, reaction
components charged with filling material by using instruments which
are simply constructed and moderately priced and which operate
reliably and with less wear. This is achieved by the present
invention in that the flowable reaction components charged with
filling material are brought to the desired high pressure in
several pressure stages with gear pumps having the same rotary
speed which are connected in series and via pipelines.
SUMMARY OF THE INVENTION
[0006] It is an object of the present invention to provide a
process for transporting flowable reaction components of a reaction
mixture, at least one of the flowable reaction components
comprising filling material, by bringing the flowable reaction
components to a predetermined pressure in several pressure stages
through the use of gear pumps operated at low rotational speed.
[0007] It is another object of the present invention to provide a
device for transporting flowable reaction components of a reaction
mixture, at least one of the flowable reaction components
comprising filling material, the device comprising gear pumps
connected in series via pipelines, wherein pressure is provided in
stages to the flowable reaction.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 illustrates the apparatus of the present invention
comprising three gear pumps arranged on a common drive shaft and
connected to one another via pipeline.
[0009] FIG. 2 illustrates a preferred embodiment of the apparatus
of the present invention comprising throttling elements arranged in
pipeline between adjacent gear pumps.
[0010] FIG. 3 illustrates another preferred embodiment of the
apparatus of the present invention comprising pressure-limiting
valves arranged in pipeline between adjacent gear pumps.
[0011] FIG. 4 illustrates yet another preferred embodiment of the
apparatus of the present invention comprising a pressure
regulator.
[0012] FIG. 5 illustrates a sectional view of a gear pump taken
along line 5 of FIG. 1 comprising gear pumps arranged in series in
a common housing.
[0013] FIG. 6 illustrates a cross sectional view of a gear pump
taken along line A-B of FIG. 5.
[0014] FIG. 7 illustrates a cross sectional view of a gear pump
taken along line C-D of FIG. 5.
DETAILED DESCRIPTION OF THE INVENTION
[0015] The invention is directed to a process for transporting and
pressurizing flowable reaction components of a reaction mixture
from at least one storage container to at least one mixing head,
comprising the steps of:
[0016] (a) providing at least a first gear pump, a second gear
pump, and a third gear pump, the first, second and third gear pumps
having the same rotary speed of up to about 800 rpm;
[0017] (b) connecting the first gear pump to the second gear pump
by a first pipeline, then connecting the second gear pump to the
third gear pump by a second pipeline;
[0018] (c) transporting the flowable reaction components, at least
one of the flowable reaction components comprising filling
material, to the first gear pump, then through the first pipeline
to the second gear pump, then through the second pipeline to the
third gear pump; and
[0019] (d) providing pressure on the flowable reaction components
in stages.
[0020] Preferably the gear pumps are operated at up to 600 rpm,
particularly preferred is a maximum of 400 rpm.
[0021] The pressure provided in each stage is preferably between
about 30 to 70 bar.
[0022] The invention is also directed to a device for transporting
flowable reaction components of a reaction mixture, at least one of
the flowable reaction components comprising filling material, from
at least one storage container to at least one mixing head,
comprising: at least a first gear pump, a second gear pump, and a
third gear pump, all having the same rotary speed, the first gear
pump being connected to the second gear pump by a first pipeline,
the second gear pump being connected to the third gear pump by a
second pipeline, and providing pressure on the flowable reaction
components in stages.
[0023] A key feature of the present invention is that several
consecutive pressure stages comprising gear pumps are operated at
the same rotary speed, connected via pipelines and arranged in
series. Another key feature of the present invention is that the
pressure level is increased by each gear pump until the desired
high pressure is attained. The present invention is illustrated
generally in FIG. 1.
[0024] Referring now to FIG. 1, gear pumps 3, 4, and 5 are the
so-called low-speed engines which are used in polyurethane
application technology but which operate under low pressure, i.e.
approximately up to about 60 bar. Gear pump 3 is preferably
connected to gear pump 4 via pipeline 6. Gear pump 4 is preferably
connected to gear pump 5 via pipeline 7. Line 8 emanating from a
storage container (not represented) leads to gear pump 3. Line 9
leads from gear pump 5 to a high-pressure mixing head (not
represented).
[0025] In a preferred embodiment of the present invention, gear
pumps 3, 4, and 5 have a drive 1 with a common drive shaft 2. As a
result, only a single drive motor is required, thus the rotary
speeds of all the gear pumps are the same.
[0026] Gear pumps 3, 4 and 5, operating under low pressure, are
subject to less wear in the delivery and metering of filled
reaction components. Surprisingly, it has been discovered that the
wear arising in the individual gear pumps remains within
justifiable limits. Additionally, the wear arising in the series
connection of gear pumps 3, 4 and 5 for the purpose of achieving
high pressure, i.e, from 120 to 250 bar, remains within justifiable
limits. Additionally, with such series connection, internal leakage
of reaction components is kept within justifiable limits. "Internal
leakage" is defined as that leakage which occurs internally between
the suction side and the pressure side of a pump, which, as a
result, generates loss in delivery and therefore affects the
efficiency of the gear pump. This can, in principle, be calculated
or preferably ascertained empirically by experiments and
compensated in the stated manner.
[0027] Less wear of gear pumps 3, 4, and 5 is achieved due to a
smaller pressure gradient per pressure stage. Thus, only a normal
overall height of the device is necessary, and as such makes the
system cost effective and manageable. Additionally, since gear
pumps 3, 4 and 5 are of a simple construction, they can be
exchanged more easily in the event of wear, which also makes the
system cost effective and manageable.
[0028] An almost equally large increase in pressure is generated in
each pressure stage. The term "pressure stage" refers to the
pressure present between the entrance (suction side) of one gear
pump and the entrance of the subsequent gear pump, such as that
pressure present between gear pumps 3 and 4 and/or that pressure
present between gear pumps 4 and 5. Since the increase in pressure
generated in each pressure stage is roughly equal, the sequence of
operations of the process becomes easily grasped. Additionally, the
equality between pressure stages makes for a more reliable
process.
[0029] The reaction components used in the present invention are
those reaction components which have a compressibility of about 3%
at 100 bar. This can, in principle, be calculated or preferably
ascertained empirically by experiments and compensated in the
stated manner. The gases (e.g. up to about volume percent (at
normal pressure) of nitrogen or air as seed gases for subsequent
foaming of the reaction mixture) that frequently have to be
introduced into the reaction components during processing amplify
this effect, according to their proportion.
[0030] This compressibility therefore becomes noticeable in a
disadvantageous manner in the course of the new type of delivery
using gear pumps in several pressure stages. Thus, preferably, at
least as much delivery-volume surplus is offered from the pressure
stage arranged upstream to the following pressure stage as is lost
in the pressure stage arranged upstream as a result of internal
leakage and compressibility of the reaction components.
[0031] The delivery-volume surplus may be provided by adjusting the
supply capacity of the upstream pump to a respective higher
capacity as compared to the subsequent pump, e.g. by providing the
upstream pump with gear wheels of corresponding about 3 to 10%
larger extension in axial dimension.
[0032] One advantage of the present invention is that the quantity
of reaction components delivered in excess from the pressure stage
upstream is drained off downstream of the pressure stage and is
either recycled back into the system or is recycled back into the
storage container. As a result, the subsequent pressure stage
always receives more flowable reaction components than it requires
for the further pressure increase of the pressurized reaction
components. As a result, an undesirable suction effect of the
subsequent pressure stage is avoided.
[0033] However, in order to keep the amount of pressurized reaction
components conveyed back as small as possible, after each pressure
stage the pressure of the reaction components that is generated
therein is preferably measured and the increase in pressure of the
pressure stage is adjusted accordingly. For the same reason, after
at least one pressure stage the pressure of the reaction components
that is generated therein is preferably measured and the increase
in pressure of the pressure stage is regulated as a function of the
measured value. This regulation is particularly appropriate when
the compressibility of the reaction components is dependent on
temperature. These measures are particularly advantageous when the
charged reaction components, viewed over time, exhibit fluctuating
gas content and/or fluctuating processing temperatures.
[0034] It is preferred that filling material be already fed into
the reaction components prior to the processing thereof. However,
filling material can also be fed into the line system upstream of
the gear pumps.
[0035] Referring now to FIG. 2, gear pump 13 is connected to gear
pump 14 via outgoing line 16. Gear pump 14 is connected to gear
pump 15 via outgoing line 17. Line 18 emanating from a storage
container (not represented) leads to gear pump 13. Line 19 leads
from gear pump 15 to a high-pressure mixing head (not represented).
Return line 20, bypassing gear pump 13, connects outgoing line 16
to line 18. Return line 21, bypassing gear pump 14, connects
outgoing line 17 to outgoing line 16. A first throttling element 22
is arranged in return line 20. A second throttling element 23 is
arranged in return line 21.
[0036] Outgoing line 16 of gear pump 13 is preferably connected via
return line 20 to either line 18 or to a storage container (not
represented). Outgoing line 17 of gear pump 14 is preferably
connected via return line 21 to either outgoing line 16 or to a
storage container (not represented). Return lines 20 and 21 allow
for excess reaction components to be recycled back into the system,
preferably to the suction side of the gear pump generating the
excess reaction components or to the storage container.
[0037] In a preferred embodiment of the present invention, gear
pumps 13, 14, and 15 have a drive 11 with a common drive shaft 12.
As a result, only a single drive motor is required, thus the rotary
speeds of all the gear pumps are the same.
[0038] Referring now to FIG. 3, gear pump 33 is connected to gear
pump 34 via outgoing line 36. Gear pump 34 is connected to gear
pump 35 via outgoing line 37. Line 38 emanating from a storage
container (not represented) leads to gear pump 33. Line 39 leads
from gear pump 35 to a high-pressure mixing head (not represented).
Return line 40, bypassing gear pump 33, connects outgoing line 36
to line 38. Return line 41, bypassing gear pump 34, connects
outgoing line 37 to outgoing line 36. A first pressure-limiting
valve 42 is arranged in return line 40. A second pressure-limiting
valve 43 is arranged in return line 41.
[0039] Pressure-limiting valve 42 opens automatically into return
line 40, at a set pressure, thereby protecting gear pump 34 against
any excessively high pressure that is generated in gear pump 33.
Pressure-limiting valve 43 opens automatically into return line 41,
at a set pressure, thereby protecting gear pump 35 against any
excessively high pressure that is generated in gear pump 34.
[0040] In a preferred embodiment of the present invention, gear
pumps 33, 34, and 35 have a drive 31 with a common drive shaft 32.
As a result, only a single drive motor is required, thus the rotary
speeds of all the gear pumps are the same.
[0041] Referring now to FIG. 4, gear pump 53 is connected to gear
pump 54 via outgoing line 56. Gear pump 54 is connected to gear
pump 55 via outgoing line 57. Line 58 emanating from a storage
container (not represented) leads to gear pump 53. Line 59 leads
from gear pump 55 to a high-pressure mixing head (not represented).
Return line 60, bypassing gear pump 53, connects outgoing line 56
to line 58. Return line 61, bypassing gear pump 54, connects
outgoing line 57 to outgoing line 56. A first throttling element 62
is arranged in return line 60. A second throttling element 63 is
arranged in return line 61. In a preferred embodiment of the
present invention, throttling element 62 can exert an influence on
the return quantity in return line 60. In another preferred
embodiment of the present invention, throttling element 63 can
exert an influence on the return quantity in return line 61.
[0042] Preferred throttling elements are orifice plates. Most
preferred throttling elements are adjustable orifice plates. In a
preferred embodiment of the present invention, the throttling
elements set the pressure for the respective return quantity in the
return line and hence the increase in pressure, or, to be more
exact, the pressure upstream of the subsequent pressure stage.
[0043] The throttling element exerts an influence on the quantity
of recycled reaction components. It is preferred that throttling
element 62 have control instrument 65 connected thereto. It is also
preferred that throttling element 63 have control instrument 67
connected thereto. Pressure gauge 64 is connected to both outgoing
line 56 and to control instrument 65. Pressure gauge 66 is
connected to both outgoing line 57 and to control instrument 67.
The control instrument is assigned to the throttling element to
which it is attached.
[0044] In a preferred embodiment of the present invention, gear
pumps 53, 54, and 55 comprise drive 51 with a common drive shaft
52. As a result, only a single drive motor is required, thus the
rotary speeds of all the gear pumps are the same.
[0045] In a preferred embodiment of the present invention, the
throttling element can be ventilated, thereby allowing agglomerates
of filling material, which are possibly dammed up in front of the
throttling element, to pass through the throttling element.
[0046] Referring now to FIGS. 5, 6 and 7, drive 71 drives common
drive shaft 72. On drive shaft 72, three gear pumps 73, 74 and 75,
are arranged in common housing 76. Gear pump 73 comprises toothed
gear 77. Gear pump 74 comprises toothed gear 78. Gear pump 75
comprises toothed gear 79. Toothed gears 77, 78 and 79 are arranged
around drive shaft 72. The toothed gears are preferably arranged in
a stepped manner. Shaft 80 comprises mating toothed gears 81, 82,
and 83. In a preferred embodiment of the present invention, toothed
gear 77 mates with mating toothed gear 81, thereby forming a first
pressure stage, while toothed gear 78 mates with mating toothed
gear 82, thereby forming a second pressure stage, and toothed gear
79 mates with mating toothed gear 83 thereby forming a third
pressure stage. Mating toothed gear 81 is separated from mating
toothed gear 82 by partition 84. Mating toothed gear 82 is
separated from mating toothed gear 83 by partition 85. Mating
toothed gear 81 has a width B1, while mating toothed gear 82 has a
width B2, and mating toothed gear 83 has a width B3. In a preferred
embodiment of the present invention, B1>B2>B3.
[0047] Gear pump 73 is connected to gear pump 74 via pipeline 86.
Gear pump 74 is connected to gear pump 75 via pipeline 87. Line 88
emanating from a storage container (not represented) leads to pump
73. Line 89 leads from pump 75 to a high-pressure mixing head (not
represented). In order to avoid internal leakage, toothed gears 77,
78 and 79 closely fit with mating toothed gears 81, 82 and 83.
Additionally, in order to avoid internal leakage, partitions 84 and
85 closely fit with housing 76.
[0048] Although the invention has been described in detail in the
foregoing for the purpose of illustration, it is to be understood
that such detail is solely for that purpose and that variations can
be made therein by those skilled in the art without departing from
the spirit and scope of the invention except as it may be limited
by the claims.
* * * * *