U.S. patent application number 10/841901 was filed with the patent office on 2005-01-13 for method of hardening a fluid mass.
This patent application is currently assigned to Technische Universiteit Delft. Invention is credited to Jansen, Johan Dirk, Jose Zitha, Pacelli Lidio.
Application Number | 20050006020 10/841901 |
Document ID | / |
Family ID | 19774296 |
Filed Date | 2005-01-13 |
United States Patent
Application |
20050006020 |
Kind Code |
A1 |
Jose Zitha, Pacelli Lidio ;
et al. |
January 13, 2005 |
Method of hardening a fluid mass
Abstract
A method of hardening a fluid mass in contact with a wall, in a
desirable shape. According to the invention, the fluid mass is a
magneto-rheological fluid mixture that in addition to at least one
hardening component comprises a particulate magnetic component,
with minimally 80% of said particles having a particle size of at
least 0.0005 mm, and a magnetic field is applied for a length of
time that suffices to achieve the desired strength by hardening in
the absence of a magnetic field.
Inventors: |
Jose Zitha, Pacelli Lidio;
(Delft, NL) ; Jansen, Johan Dirk; (Delft,
NL) |
Correspondence
Address: |
PEACOCK MYERS AND ADAMS P C
P O BOX 26927
ALBUQUERQUE
NM
871256927
|
Assignee: |
Technische Universiteit
Delft
Delft
NL
|
Family ID: |
19774296 |
Appl. No.: |
10/841901 |
Filed: |
May 7, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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10841901 |
May 7, 2004 |
|
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PCT/NL02/00729 |
Nov 12, 2002 |
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Current U.S.
Class: |
156/71 ;
156/272.4; 264/426; 264/427 |
Current CPC
Class: |
C09K 8/493 20130101;
C04B 14/34 20130101; C04B 26/02 20130101; C04B 28/02 20130101; C04B
14/34 20130101; C04B 2111/00422 20130101; C04B 40/0209 20130101;
C09K 8/44 20130101; C04B 40/0209 20130101; E21B 33/14 20130101;
C04B 40/0209 20130101 |
Class at
Publication: |
156/071 ;
156/272.4; 264/427; 264/426 |
International
Class: |
E04B 002/00; E04F
013/00 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 12, 2001 |
NL |
NL 1019349 |
Claims
What is claimed is:
1. A method of hardening a fluid mass in contact with a wall,
wherein the fluid mass is a magneto-rheological fluid mixture that
in addition to at least one hardening component comprises a
particulate magnetic component, with minimally 80% of those
particles having a particle size of at least 0.0005 mm, and
wherein: the fluid mixture is brought into a desired shape, and a
magnetic field is applied for a sufficient length of time to
achieve a desired strength by hardening in the absence of a
magnetic field.
2. A method according to claim 1, wherein the hardening component
comprises a fluid cement or fluid concrete.
3. A method according to claim 1, wherein the hardening component
is molten plastic, and hardening occurs as a result of the molten
plastic cooling down.
4. A method according to claim 1, wherein the hardening component
comprises a polymerisable compound, which is cured by means of
polymerization.
5. A method according to claim 1, wherein the hardening component
comprises a cross-linkable polymer, and curing occurs by
cross-linking of the polymer.
6. A method according to claim 1, wherein the fluid mixture
comprises 10% to 45% vol./vol. of a magnetic component chosen from
the group consisting of iron, cobalt and vanadium.
7. A method according to claim 1, wherein minimally 80% of the
particles of the particulate component have a particle size between
0.005 to 0.5 mm.
8. A method according to claim 1, wherein during hardening, the
applied magnetic field has an intensity of at least 0.05 Tesla.
9. A method according to claim 1, wherein the applied magnetic
field is initially stronger, and its intensity is reduced once the
fluid mass is set to some extent.
10. A method according to claim 1, wherein the fluid mixture is
supplied via a nozzle that is screened from a magnetic field.
11. The use of a magneto-rheological fluid mixture that, in
addition to at least one hardening component, comprises a
particulate magnetic component to prevent gas migration in cement
during the application and/or setting of cemen around a pipe for
the formation of a cylindrical wall part of a bored well.
12. A magneto-rheological composition capable of hardening.
Description
[0001] The present invention relates to a method of hardening a
fluid mass in contact with a wall.
[0002] Such a method is generally known, for example, for setting
concrete. With some applications a force is exerted during setting,
which results in the fluid mass setting in an undesirable shape.
With some applications it is further desirable for the fluid mass
to be able to bear a force as soon as possible after its delivery
to the chosen place. An example of such an application is the
introduction of a pipe structure in bore holes. Such a pipe
structure is needed to prevent the collapse of the bore hole. A
cylindrical metal pipe is lowered into the bore hole to the desired
depth, after which cement is pumped via the bore hole through the
lowered pipe. Via the bottom end of the pipe the cement flows
upward around the outer wall of the pipe. This provides a seal
around the pipe. In a soil stratum comprising high-pressure gas the
gas may penetrate into the not yet set cement, thereby weakening
it. This phenomenon is called gas migration. Due to the weakening
it becomes possible for gas to escape from the bore hole in an
uncontrolled manner.
[0003] It is the object of the present invention to provide a
method allowing a force to be applied to the mass even while the
fluid mass is setting, without causing it to set in an undesirable
shape. It is a further object to provide a method by which, after
the delivery of the fluid mass in the chosen place, the delivered
mass is able to bear a force.
[0004] To this end the method according to the present invention is
characterised in that the fluid mass is a magneto-rheological fluid
mixture that in addition to at least one hardening component
comprises a particulate magnetic component, with minimally 80% of
those particles having a particle size of at least 0.0005 mm,
[0005] the fluid mixture is brought into a desired shape, and
[0006] a magnetic field is applied for a sufficient length of time
to achieve the desired strength by setting in the absence of a
magnetic field.
[0007] By applying a magnetic field it is possible to prevent the
fluid mass from acquiring an undesirable shape before setting,
while achieving that it is able to bear a force immediately after
application.
[0008] According to a first embodiment, the hardening component
comprises a fluid cement or fluid concrete.
[0009] Such a method is useful for the problems of gas migration
described above. The wall is formed by a part of the casing of the
bore hole, and possibly also by the rock surrounding it. When
speaking of a desired shape in the present invention, it is not
necessary for the entire shape of the set fluid to be known
beforehand, rather it suffices if at least a part has a desired
shape, as in this case determined by the wall of the casing. In
addition, the method is useful for civil engineering constructions
such as buildings and tunnels. The method is believed to be
especially advantageous if these are made by means of slide
forming. The method is also useful for forming concrete
construction elements such as floor and wall components and piles.
The resulting elements can be taken from the place of manufacture
to another site sooner, for example to a site where they are
allowed to finish setting.
[0010] U.S. Pat. No. 4,802,534 describes a method in which a
cement-comprising fluid is used to provide a bored well with
cement. The cementitious fluid is a ferrofluid comprising particles
up to 4000 .ANG.. A ferrofluid is a fluid that can move under the
influence of a (alternating) magnetic field. In contrast with the
composition described in U.S. Pat. No. 4,802,534, the method
according to the invention makes it possible to prevent gas
migration and the ensuing weakening. Experiments have shown that by
applying a magnetic field according to the invention, the viscosity
of the mixture was increased by a factor of >25.
[0011] According to an alternative embodiment the hardening
component is molten plastic, and hardening occurs as a result of
the molten plastic cooling down.
[0012] This method makes it possible among other things to
manufacture large thermoplastic objects that may be removed from
the mould quickly.
[0013] For the manufacture of plastic products the hardening
component may comprise a polymerisable compound, which is cured by
means of polymerisation. Instead of that, or in addition, the
curing component may comprise a cross-linkable polymer, and curing
occurs by cross-linking of the polymer.
[0014] The magnetic component may be any magnetic component, e.g. a
paramagnetic component, and preferably a ferro-magnetic component.
It will be clear to the person not skilled in the art that the
amount of magnetic component may vary widely, depending on the
requirements with regard to mouldability during curing.
Furthermore, if the content of magnetic component is low, a
stronger magnetic field may be applied, and vice versa. The fluid
mixture suitably comprises 2 to 50% vol./vol., and preferably 10 to
45% vol./vol. of a magnetic component chosen from iron, cobalt
and/or vanadium.
[0015] According to common practice in the art, the percentage
relates to the weight of the particles. The size of at least 80% of
the particles of the particulate component is between 0.0005 and 5
mm, preferably between 0.005 and 0.5 mm.
[0016] It is essential that the particles exhibit sufficient
interaction (cohesion/adhesion) with the surrounding curable fluid
to influence the flow behaviour. The viscosity must be increased at
least ten-fold, at the chosen field intensity. The particles may
optionally be provided with a coating, or included in a larger
object such as a sphere. Optionally, a coating may be provided to
protect the particles from oxidation. In this way a limited amount
of the actual magnetic component may still have a considerable
effect on the fluid mass, and this may be cost-effective.
[0017] During hardening, the applied magnetic field usually has an
intensity of at least 0.01 Tesla, and preferably at least 0.05, for
example 0.05 to 0.5 Tesla.
[0018] Obviously, a suitable magnetic field depends on the fluid
mass in question. Simple experiments will enable the ordinary
person skilled in the art to determine a suitable magnetic field
intensity. Lower contents of magnetic particles will generally
require higher magnetic field intensities.
[0019] If the magnetic field is generated electrically, it is
possible to save electricity by initially applying a stronger
magnetic field, and reducing the intensity once the fluid mass is
set to some extent. With slide forming techniques a permanent
magnet may be used, which will gradually become further removed
from fluid mass applied earlier, and which is thus in a more
advanced stage of hardening.
[0020] According to one particular embodiment the fluid mixture is
supplied via a nozzle that is screened from a magnetic field.
[0021] This makes it possible to have a permanent magnetic field
without impeding the supply of fluid mixture. A suitable screening
material is mu-metal.
[0022] The invention also relates to the use of a
magneto-rheological fluid mixture that, in addition to at least one
hardening component, comprises a particulate magnetic component to
prevent gas migration in cement during the application and/or
setting of cement around a pipe for the formation of a cylindrical
wall part of a bored well.
[0023] Finally, the invention relates to a magneto-rheological
composition capable of hardening.
* * * * *