JP4313449B2 - Catalyst slurry adjuster - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a catalyst slurry adjusting device that adjusts a catalyst slurry, and more particularly to a catalyst slurry adjusting device that prevents a change in the viscosity of a catalyst slurry in a step of holding the catalyst slurry.
[0002]
[Prior art]
Exhaust gas discharged from an internal combustion engine such as an automobile engine contains harmful components such as hydrocarbon (HC), carbon monoxide (CO), and nitrogen oxide (NOx). If this exhaust gas is discharged as it is, it causes pollution and environmental degradation. For this reason, these exhaust gases are exhausted into the atmosphere after being purified using a catalytic converter or the like.
[0003]
The catalytic converter is composed of a catalyst carrier formed of a heat-resistant ceramic, a heat-resistant metal, etc., a heat-resistant porous layer coated on the surface of the catalyst carrier, and a catalyst component supported on the porous layer. ing. The porous layer of such a catalytic converter is manufactured by contacting and impregnating a catalyst carrier with a slurry of heat-resistant powder containing or not containing a catalyst component.
[0004]
For this catalyst slurry, for example, a predetermined amount of a slurry raw material consisting of a catalyst component such as activated alumina powder and ceria powder and a binder, pure water, etc., is weighed and put into a slurry stock tank of a catalyst slurry adjusting device. It was adjusted by stirring.
[0005]
[Problems to be solved by the invention]
When the adjusted catalyst slurry is held as it is, the particle components dispersed in the slurry are loosely bonded to each other due to the intermolecular force, and the slurry viscosity varies. If the slurry viscosity varies, the amount of the catalyst component supported on the catalyst carrier changes, which is not preferable as a catalytic converter.
[0006]
The thixotropy of the catalyst slurry changes as the liquid temperature changes. When the thixotropy of the catalyst slurry changes, the viscosity of the catalyst slurry changes, and the amount of slurry adhering to the catalyst carrier varies. Variation in the amount of slurry adhered was undesirable because it resulted in variations in the purification performance of the produced catalytic converter.
[0007]
Furthermore, as in the conventional catalyst slurry adjusting device, the catalyst slurry adjusting device that agitates and adjusts the catalyst slurry in the slurry stock tank, the catalyst slurry in the slurry stock tank is used with the use of the catalyst slurry. The amount will decrease. When the amount of catalyst slurry in the slurry stock tank changes, the stirring speed changes. As the stirring speed changes, the slurry viscosity also changes.
[0008]
In addition, the conventional catalyst slurry adjusting apparatus is stirring the catalyst slurry by rotating the rotating blades in the slurry. However, if the rotating speed of the rotating blades becomes slow, the catalyst slurry is not sufficiently stirred. As a result, the slurry viscosity varies. Further, when the rotational speed is increased, air enters the catalyst slurry.
[0009]
This invention is made | formed in view of the said actual condition, and makes it a subject to provide the slurry adjustment apparatus for catalysts which suppressed the change of the viscosity of the slurry for catalysts in an adjustment and a holding process.
[0010]
[Means for Solving the Problems]
In order to solve the above problems, the present inventors have repeatedly studied on means for constantly applying the same shearing force to the catalyst slurry in the catalyst slurry adjusting apparatus, and as a result, provided slurry circulating means having both ends opened in the slurry stock tank, It has been found that the above problem can be solved by circulating the catalyst slurry through the catalyst slurry circulating means.
[0011]
That is, the catalyst slurry adjusting apparatus of the present invention includes a slurry stock tank for adjusting and holding the catalyst slurry, a slurry supply means for supplying the catalyst slurry to the slurry stock tank, and one end and the other end in the slurry stock tank. A slurry circulating means for circulating the catalyst slurry from one end to the other end, a slurry delivery means connected to the slurry circulating means for sending the catalyst slurry circulating in the slurry circulating means, and a slurry stock A viscometer that measures the viscosity of the slurry in the tank, a stirrer that is connected to the viscometer and stirs the slurry in the slurry stock tank, and is integrally formed in the slurry stock tank to measure the slurry temperature and keep the slurry temperature constant. And a temperature control means for maintaining the temperature .
[0012]
The catalyst slurry adjusting device of the present invention keeps the viscosity of the catalyst slurry uniform by circulating the catalyst slurry and applying a flow that gives the same shearing force to the catalyst slurry. In addition, the viscosity of the catalyst slurry in the slurry stock tank is kept constant. Therefore, the catalyst slurry can be supplied and applied to the catalyst carrier in a stable state at all times.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
The catalyst slurry adjusting device of the present invention has slurry circulating means for opening one end and the other end in the slurry stock tank and circulating the catalyst slurry from one end to the other end. The catalyst slurry is circulated through the slurry circulation means to be stirred, thereby preventing the catalyst slurry from gelling.
[0014]
The slurry circulating means is means for opening one end and the other end in the slurry stock tank and circulating the catalyst slurry from the one end portion through the other end portion. As the slurry circulating means, for example, one end is opened in the catalyst slurry in the slurry stock tank and the other end is opened in the catalyst slurry, and the catalyst slurry provided in this pipe is circulated. A circulation means comprising a pump as a power source to be driven can be given.
[0015]
The catalyst slurry adjusting device of the present invention has a slurry stock tank for adjusting and holding the catalyst slurry. The slurry stock tank is for adjusting or holding the catalyst slurry, and the slurry stock tank used in the conventional slurry adjusting apparatus can be used.
The catalyst slurry adjusting device of the present invention has a slurry supply means for supplying the catalyst slurry to the slurry stock tank. The slurry supply means supplies the slurry for catalyst to the slurry stock tank, and can control the amount of slurry in the slurry stock tank within a certain range. For example, a pipe line having a raw material supply hole opened in the slurry slot tank can be mentioned.
[0016]
The supply of the catalyst slurry in this slurry supply means may be either the supply in the slurry raw material state for forming the catalyst slurry or the supply in the slurry state produced as the catalyst slurry, but it was previously formed as a slurry. Supply in a slurry state is preferred.
The catalyst slurry adjusting device of the present invention has a slurry delivery means connected to the slurry circulation means and delivering the catalyst slurry circulating through the slurry circulation means. The slurry delivery means is means for delivering the catalyst slurry adjusted by the catalyst slurry adjustment device to supply to an external device such as a catalyst slurry application device for applying the catalyst slurry to the catalyst carrier.
[0017]
The slurry delivery means and the slurry circulation means are connected via a switching device. That is, by providing the switching device at the connection portion between the slurry delivery means and the slurry circulation means, the catalyst slurry circulating through the slurry circulation means can selectively flow through the slurry delivery means.
Examples of the slurry delivery means and the switching device include a pipe line similar to the slurry circulation means to which the slurry delivery means is connected as the slurry delivery means, and a valve for connecting the pipeline as the switching apparatus.
[0018]
A viscometer that measures the viscosity of the slurry in the slurry stock tank, a stirrer that is connected to the viscometer and stirs the slurry in the slurry stock tank, and is integrally formed in the slurry stock tank to measure the slurry temperature and the slurry temperature It is preferable to have temperature control means for keeping the temperature constant.
The viscometer measures the viscosity of the slurry in the slurry stock tank. When the viscosity of the catalyst slurry changes, the amount of slurry adhering to the catalyst carrier varies, so that the viscosity is measured using a viscometer in order to control the viscosity of the catalyst slurry.
[0019]
The stirrer is connected to the viscometer and stirs the slurry in the slurry stock tank. When the catalyst slurry is discharged, the amount of catalyst slurry in the slurry stock tank changes, and the stirring speed of the stirrer changes. When the stirring speed is changed, the slurry viscosity of the catalyst slurry is changed, resulting in a problem that the amount of the catalyst slurry attached to the catalyst carrier varies. For this reason, in order to keep the viscosity of the catalyst slurry in the slurry stock tank in a certain range, the stirring of the stirrer connected to the viscometer is controlled.
[0020]
As the stirrer, a stirrer used in a conventional catalyst slurry adjusting apparatus can be used. That is, a stirrer composed of a motor and a rotating blade connected to the tip of the rotating shaft of the motor can be used. The stirrer can control the rotation speed by feeding back the viscosity of the catalyst slurry measured by the viscometer.
[0021]
The temperature adjusting means is integrally formed in the slurry stock tank, measures the slurry temperature, and keeps the slurry temperature constant. By maintaining the temperature of the catalyst slurry in a certain range by the temperature adjusting means, fluctuations in the viscosity of the catalyst slurry are suppressed. That is, when the temperature of the catalyst slurry changes, the thixotropy of the catalyst slurry changes. The change in the thixotropy of the catalyst slurry causes a change in the viscosity of the catalyst slurry, and further causes variation in the amount of catalyst slurry adhering to the catalyst carrier.
[0022]
The temperature control means includes a temperature measuring device that measures the temperature of the catalyst slurry and a temperature controller that keeps the temperature of the catalyst slurry constant. Any temperature measuring device can be used as long as it can measure the temperature of the slurry for catalyst, and a thermocouple or the like can be used. The temperature controller is capable of feeding back and heating the temperature of the catalyst slurry measured by the temperature measuring device.
[0023]
The slurry delivery means preferably has a return means for adding the excess amount of the catalyst slurry delivered from the slurry circulation means to the slurry stock tank. The return means is means for supplying again the excess amount of the catalyst slurry that has been excessively delivered from the slurry delivery means to the external device to the slurry stock tank. By having the return means, the loss of the slurry for the catalyst can be suppressed.
[0024]
The catalyst slurry adjusting device preferably has water supply means for supplying water to the slurry stock tank. That is, the catalyst slurry supplied into the slurry stock tank by the return means has an appropriate viscosity because, for example, when the catalyst slurry comes into contact with the catalyst carrier, the moisture in the catalyst slurry is absorbed by the catalyst carrier. This is because it is necessary to supply water in order to hold the water.
[0025]
The slurry delivery means preferably has gas supply means for supplying pressurized gas into the slurry circulation means. The gas supply means pushes the catalyst slurry circulating in the slurry circulation means by supplying pressurized gas to the slurry circulation means. That is, the catalyst slurry is delivered to the slurry delivery means using the pressure of the pressurized gas.
[0026]
The gas supply by the gas supply means is performed when the slurry is sent to the slurry delivery means, and it is not always necessary to supply the gas . Further, when the catalyst slurry is circulating in the slurry circulating means, no pressure is applied.
[0027]
The slurry circulating means preferably has a slurry reservoir. By having the slurry reservoir, a sufficient amount of the catalyst slurry can be sent when the catalyst slurry circulating through the slurry circulation means is sent to the slurry delivery means. Also in the slurry reservoir, the catalyst slurry is circulated in the same manner as the slurry circulation means. For this reason, variation in slurry viscosity due to stagnation within the slurry reservoir does not occur.
[0028]
As the slurry reservoir, for example, a pipe formed so as to have a large inner diameter in a pipe line forming the slurry circulating means can be mentioned.
The gas supply means preferably has a chamber. Since the pressurized gas is stored in the chamber, the backflow of the catalyst slurry from the slurry circulation means connected to the gas supply means to the gas supply means can be suppressed.
[0029]
The catalyst slurry is preferably composed of an inorganic oxide, a binder, water and / or a noble metal-containing solution. The catalyst slurry preferably has a viscosity of 60 cps.
Examples of the inorganic oxide include at least one inorganic oxide selected from the group consisting of activated alumina, silica, titania, ceria, zirconia, and the like.
[0030]
The stirrer preferably stirs the catalyst slurry at a rotation speed of 15 to 35 Hz. By setting the rotational speed of the stirrer to 15 to 35 Hz, the viscosity of the slurry for catalyst can be kept within the optimum range of 60 cps ± 10%. When the rotational speed is less than 15 Hz, the viscosity of the catalyst slurry increases, and when it exceeds 35 Hz, the viscosity of the catalyst slurry decreases.
[0031]
The temperature controller preferably maintains the slurry temperature within a range of 15 to 35 ° C. As the slurry temperature increases, the water content of the slurry evaporates, the proportion of the solid component of the slurry increases, and the viscosity increases. Further, depending on the components contained in the slurry, a reaction occurs and the viscosity of the slurry increases. When the slurry temperature is lowered, condensation occurs due to the temperature difference between the outside air temperature and the slurry temperature, and the ratio of the moisture in the slurry due to the condensed moisture increases. An increase in the water content causes the viscosity of the slurry to decrease. For this reason, it is preferable to maintain the temperature of a slurry at 15-35 degreeC of a normal temperature range.
[0032]
【Example】
Hereinafter, the present invention will be described using examples.
(Example)
As an example of the present invention, a catalyst slurry adjusting device was prepared. The configuration of the catalyst slurry adjusting apparatus of this example is shown in FIG.
[0033]
The catalyst slurry adjusting apparatus of the present embodiment includes a slurry stock tank 10, a slurry circulation pipe 20, a slurry delivery pipe 30, a gas supply pipe 40, a slurry supply pipe 50, a stirrer 60, and a temperature controller 70. , Is composed of.
The slurry stock tank 10 is a tank-like container having an open top in which charged slurry is held.
[0034]
The slurry circulation pipe 20 is a pipe line in which one end portion 21 opens to the bottom surface of the slurry stock tank 10, passes through the outside of the slurry stock tank 10, and the other end portion 22 opens to a position above the slurry stock tank 10. The slurry circulation pipe 20 is provided with a pump 25 between one end 21 and the other end 22, and a valve 23 between the pump 25 and the other end 22. The pump 25 discharges the slurry sucked from the one end portion 21 from the other end portion 22. The valve 23 shuts off the slurry circulating in the slurry circulation pipe 20.
[0035]
The slurry circulation pipe 20 has a slurry reservoir 26 in which the inner diameter of the pipe is increased. The slurry reservoir 26 is provided to hold the slurry fed from the slurry delivery pipe 30 to the external device in the slurry circulation pipe 20 for delivering a predetermined amount.
The slurry delivery pipe 30 is connected between the pump 25 of the slurry circulation pipe 20 and the slurry reservoir 26. The slurry delivery pipe 30 is a conduit for delivering the slurry circulating through the slurry circulation pipe 20 and the slurry reservoir 26 to an external device. The slurry discharge pipe 30 and the slurry circulation pipe 20 are connected via a valve 31 capable of switching the pipe through which the slurry flows.
[0036]
A slurry reduction pipe 35 is connected to the slurry delivery pipe 30 via a valve 32. The slurry reduction pipe 35 is a pipe for reducing the excess amount of the slurry sent to the external device to the slurry stock tank 10, and the opening 33 opens above the slurry stock tank 10. The valve 32 can switch the conduit through which the slurry flows from the valve 31 to the external device or from the external device to the opening 33.
[0037]
The gas supply pipe 40 is connected to the slurry circulation pipe 20 and supplies pressurized gas to the slurry circulation pipe 20. By supplying the pressurized gas supplied from the gas supply pipe 40, the slurry in the slurry circulation pipe 20 is sent to the slurry delivery pipe 30.
The gas supply pipe 40 is provided with a valve 41 for controlling the supply of pressurized gas and a valve 42 for discharging the pressurized gas in the gas supply pipe 40. Further, a gas reservoir 45 for holding a pressurized gas is provided between the valve 41 and the slurry circulation pipe 20. By having the gas reservoir 45, the gas supply pipe 40 can prevent the backflow of the slurry from the slurry circulation pipe 20.
[0038]
The slurry supply pipe 50 is a pipe that supplies the raw slurry to the slurry stock tank 10, and one end 51 opens above the slurry stock tank 10.
The water supply pipe 55 also has one end 56 opened above the slurry stock tank 10 in the same manner as the slurry supply pipe 50.
The stirrer 60 has a motor 61 that can control the number of rotations, and a rotating blade 62 at the tip of the rotating shaft of the motor 61. The stirrer 60 is installed so that the rotary blade 62 can rotate in the slurry so that the slurry in the slurry stock tank 10 can be stirred. As the rotating blade 62, a rotating blade having a shape approximately the same as the tank diameter of the slurry stock tank 10 was used.
[0039]
The viscosity of the slurry has a stable region when the shearing force (stirring force) exceeds a certain level (viscosity bottom). Therefore, it is only necessary to increase or decrease the stirring force to that region. The shape and capacity of the slurry stock tank It does n’t matter. For this reason, the shape of the rotary blade 62 is preferably a rotary blade having the same shape as the tank diameter.
The stirrer 60 is connected to a viscometer 65. The stirrer 60 is connected to the viscometer 65 via a control device 67 that controls the rotational speed of the stirrer 60. Since the stirrer 60 is connected to the viscometer 65, the slurry viscosity obtained by the viscometer 65 is fed back, and the number of revolutions of the stirrer 60 is controlled to maintain the slurry viscosity at a constant value.
[0040]
The temperature controller 70 is formed integrally with the slurry stock tank 10 and includes a thermometer for measuring the slurry temperature and a heater connected to the thermometer. The temperature controller 70 keeps the slurry temperature constant by feeding back the slurry temperature measured by a thermometer and controlling the heater.
(Slurry circulation)
The circulation of the slurry in the catalyst slurry adjusting apparatus of the present example is as follows.
[0041]
The slurry supplied to the slurry stock tank 10 is reduced and circulated by the pump 25 from the one end portion 21 of the slurry circulation pipe 20 to the slurry stock tank 10 from the other end portion 22 through the valve 31, the slurry reservoir 26, and the valve 23. .
While the slurry circulates through the slurry circulation pipe 20, the valve 31 is adjusted so that the slurry flows through the slurry circulation pipe 20 so that the circulating slurry does not flow into the slurry delivery pipe 30. Further, the valve 42 provided in the gas supply pipe 40 is opened and the valve 41 is shut off, so that pressurized gas does not enter the gas supply pipe 40 and the slurry circulation pipe 20. .
[0042]
(Slurry delivery)
The slurry is sent out from the catalyst slurry adjusting apparatus of the present embodiment by the following procedure.
First, the slurry is circulated through the slurry circulation pipe 20.
Thereafter, the valve 23 is shut off and the valve 31 is switched so that the slurry flows from the slurry reservoir 26 of the slurry circulation pipe 20 to the slurry delivery pipe 30. The slurry delivery pipe 30 switches the valve 32 so that the slurry does not flow into the slurry reduction pipe 35.
[0043]
Thereafter, the valve 42 of the gas supply pipe 40 is shut off, the valve 41 is opened, and a pressurized gas is introduced into the gas supply pipe 40 and the slurry circulation pipe 20, and the slurry circulation pipe 20 and the slurry are caused by the pressure of this gas. The slurry in the reservoir 26 is sent to an external device of the slurry delivery pipe 30.
After the slurry is sent out, the respective valves are adjusted so that the slurry is circulated again. At this time, the valve 32 is switched so that the slurry flows from the external device side to the slurry reduction pipe 35.
[0044]
(Evaluation)
The evaluation of the catalyst slurry adjusting apparatus of the example was performed by measuring the slurry viscosity when the amount of slurry in the slurry stock tank was changed.
120 kg of slurry with alumina as the main component and specific gravity adjusted to 1.5% and solid content of 45% is put in a slurry stock tank, and the slurry temperature is kept at 25 ± 0.5 ° C by ON / OFF control of temperature controller. I did it. When the rotational speed of the stirrer was adjusted so that the viscosity of the slurry measured with a viscometer in this state was 60 cps, it was 25 Hz.
[0045]
Under this condition (slurry temperature: 25 ± 0.5 ° C., rotation speed: 25 Hz), when the slurry is gradually discharged from the slurry stock tank, the viscosity of the slurry starts to drop when the slurry weight falls below 60 kg. It was.
Here, when the slurry weight in the slurry stock tank was 60 kg, the stirring speed was adjusted so that the slurry viscosity was 60 cps. The rotation speed at this time was 18 Hz.
[0046]
Moreover, when the slurry raw material was supplied to the slurry stock tank and the amount of the slurry was gradually increased under these conditions (slurry temperature: 25 ± 0.5 ° C., rotation speed: 18 Hz), the viscosity of the slurry began to rise. .
The relationship between the slurry weight and slurry viscosity at various rotational speeds when the slurry temperature was 25 ± 0.5 ° C. was measured, and the measurement results are shown in FIG.
[0047]
From FIG. 2, when the rotational speed is 18 Hz, the viscosity is 60 cps up to the slurry weight of 60 kg, but the viscosity increases when it exceeds 60 kg. When the rotational speed is 25 Hz, the viscosity is 60 cps when the slurry weight is around 60 kg. Furthermore, when the rotational speed is 25 Hz, the viscosity is maintained in the vicinity of 60 cps even if the slurry weight exceeds 100 kg.
[0048]
In the catalyst slurry adjusting apparatus of the example, when the stirring speed was controlled by feeding back the viscosity data measured so as to keep the viscosity of the slurry at 60 cps, it was 25 Hz when the slurry weight in the slurry stock tank was 90 kg or more. When it was 60 or more and less than 90 kg, it was 22 Hz, and when it was less than 60 kg, it was 18 Hz.
The slurry adjusting apparatus for a catalyst of this example was able to always control the slurry viscosity in the stock tank within 60 cps ± 10% by always feeding back the viscosity data measured by the viscometer and controlling the stirring speed.
[0049]
【The invention's effect】
The catalyst slurry adjusting device of the present invention keeps the viscosity of the catalyst slurry constant because the slurry is circulated through the slurry circulation means opened in the slurry stock tank so that the same shear force is always applied to the catalyst slurry. ing.
In addition, the catalyst slurry adjusting apparatus of the present invention has a stirrer that is connected to a viscometer and stirs the slurry in the slurry stock tank, so that the viscosity of the slurry can be kept constant even if the amount of the slurry changes. .
[0050]
The catalyst slurry adjusting device of the present invention has an effect that the catalyst slurry can be supplied and applied to the catalyst carrier in a stable state at all times.
[Brief description of the drawings]
FIG. 1 is a view showing a catalyst slurry adjusting apparatus of an embodiment.
FIG. 2 is a graph showing the relationship between the amount of slurry and the viscosity of slurry for each stirring speed of a slurry containing alumina as a main component.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Slurry stock tank 20 ... Slurry circulation pipe 30 ... Slurry delivery pipe 40 ... Gas supply pipe 50 ... Slurry supply pipe 60 ... Stirrer 70 ... Temperature controller

Claims (9)

A slurry stock tank for adjusting and holding catalyst slurry; and
Slurry supply means for supplying the catalyst slurry to the slurry stock tank;
One end and the other end open in the slurry stock tank, and slurry circulating means for circulating the catalyst slurry from the one end portion through the other end portion;
A slurry delivery means connected to the slurry circulation means for delivering the catalyst slurry circulating through the slurry circulation means;
A viscometer for measuring the viscosity of the slurry in the slurry stock tank;
A stirrer connected to the viscometer to stir the slurry in the slurry stock tank;
A temperature control unit that is integrally formed with the slurry stock tank, measures the slurry temperature, and keeps the slurry temperature constant;
A slurry adjusting device for a catalyst, comprising:   2. The catalyst slurry adjusting device according to claim 1, wherein the slurry delivery unit has a return unit that adds an excess amount of the catalyst slurry delivered from the slurry circulation unit to the slurry stock tank. 3.   The catalyst slurry adjusting apparatus according to claim 1, wherein the catalyst slurry adjusting apparatus includes water supply means for supplying water to the slurry stock tank.   The catalyst slurry adjusting apparatus according to claim 1, wherein the slurry delivery unit includes a gas supply unit configured to supply a pressurized gas into the slurry circulation unit.   The catalyst slurry adjusting device according to claim 1, wherein the slurry circulating means has a slurry reservoir. 5. The catalyst slurry adjusting apparatus according to claim 4, wherein the gas supply means has a gas reservoir.   The catalyst slurry adjusting apparatus according to claim 1, wherein the catalyst slurry comprises an inorganic oxide, a binder, water and / or a noble metal-containing solution.   The catalyst temperature adjusting device according to claim 1, wherein the temperature controller maintains the slurry temperature within a range of 15 to 35 ° C.   The catalyst stirrer according to claim 1, wherein the stirrer stirs the catalyst slurry at a rotation speed of 15 to 35 Hz.

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