JP2001278904A - Method and apparatus for vapor phase polymerization - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect a formation of a polymer block formed in a fluidized bed and to control the working of the fluidized bed reactor by responding to the detected result. SOLUTION: The vapor phase polymerization apparatus composed by supplying a solid catalyst for polymerization to a fluidized bed reactor 1 and by forming a fluidized bed 4 in the fluidized bed reactor 1 by blowing a predetermined density of gaseous monomer from the bottom of the fluidized bed reactor 1 with a blower 8 to obtain a polymer by a vapor phase polymerization reaction in the fluidized bed 4 comprises; 1) a detection means which consists of an electric detection means 13 detecting an oscillation of the fluidized bed reactor 1 and a distinction part 14, and 2) an observation and control part 15 which controls a reaction condition of the fluidized bed reactor 1 toward inhibition of a block formation based on a result detected by the detection means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for supplying a solid catalyst for polymerization into a fluidized bed reactor, and a method for supplying gaseous monomers from a bottom of the fluidized bed reactor through a dispersion plate by a blower. To form a fluidized bed in a fluidized-bed reactor, and to produce a polymer by a gas-phase polymerization reaction in the fluidized-bed reactor.

[0002]

2. Description of the Related Art Heretofore, when obtaining a polyolefin such as polyethylene, for example, a gas phase polymerization method in which an olefin monomer such as ethylene is polymerized in the gas phase in the presence of a titanium-based solid catalyst has been used. In such a gas-phase polymerization method, for example, as shown in FIG. 6, the solid catalyst A is supplied into the fluidized-bed reactor 110 through a supply line 112, and the fluidized-bed reactor A is supplied through a supply line 113. A gaseous olefin is blown from the bottom of the fluidized bed reactor 110 through a gas dispersion plate 111 such as a perforated plate disposed near the bottom of the fluidized bed reactor 110 to form a fluidized bed (reaction system) 114.
Is maintained in a fluidized state, and a polymerization reaction is performed in the fluidized bed 114. The polymer particles produced by the polymerization reaction in the fluidized bed 114 are continuously extracted from the fluidized bed reactor 110 via a line 115. In addition, unreacted gaseous olefins and the like that have passed through the fluidized bed 114 of the fluidized bed reactor 110 have a reduced flow velocity in the deceleration region 116 provided above the fluidized bed reactor 110, and the fluidized bed reaction The gas is discharged out of the fluidized bed reactor 110 through a gas outlet 110A provided at the upper part of the vessel 110. On the other hand, unreacted gaseous olefin and the like discharged from the fluidized bed reactor 110 are blown into the fluidized bed 114 in the fluidized bed reactor 110 again through the circulation line 117. The gaseous olefin is cooled through a heat exchanger (cooling device) 119 disposed on the circulation line 117, and is supplied to the blower 118 via a supply line 120 which joins the circulation line 117. 118 means the continuous fluidized bed reactor 11
0 is supplied.

[0003]

The fluidized bed 11
If there is a portion in 4, where the state of the catalyst, polymer, gaseous monomer, and the like is non-uniform, a lump of polymer is formed.
This mass blocks a uniform polymerization reaction in the fluidized bed 114. Furthermore, there is a case where a vicious circle occurs in which the non-uniform portion is enlarged due to the presence of the lump and the lump is promoted.

[0004] Therefore, it is necessary to perform control to detect the presence or absence of such a lump formation and to maintain the state in the fluidized bed 114 at a point in time when the lump is detected. As a method of detecting lump formation, for example, as disclosed in Japanese Patent Application Laid-Open No. 4-361150, a fluidized bed reactor 110 detects a change in capacitance between a detection point and a wall surface in the vicinity thereof. There is a method of arranging a capacitance detecting means, detecting a change in the capacitance, and confirming that a lump is formed in the fluidized bed.

[0005] However, in this method, installation of the capacitance detecting means is expensive, and there are safety problems such as leakage of high-pressure gas and necessity of explosion-proof measures. Furthermore, the lump detection sensitivity differs depending on the arrangement position of the detection means,
It is possible to objectively evaluate the obtained data by changing the capacitance due to factors other than lump formation, for example, the influence of impurities such as hydrogen, carbon monoxide and carbohydrate mixed in the raw material gas. It was difficult.

[0006] Japanese Patent Application Laid-Open No. 4-361150 discloses that a product take-out section (not shown) for taking out a polymer 115 produced by a fluidized bed reactor 110 has a lump in the produced polymer. A method of arranging a vibration sensor for detecting the vibration of the product take-out part generated during the generation, and confirming that a lump has been generated when the vibration sensor detects the vibration is also described. I have.

However, this method is a method of detecting a lump using the polymer that has escaped from the reactor, and does not directly monitor the state in the fluidized-bed reactor. It was difficult to detect clump formation in real time only by the monitoring method using. Further, as another example of a method for detecting agglomeration, an infrared sensor is disposed in a fluidized-bed reactor, and the density of the powdery polymer is monitored using the infrared sensor. Is obtained, a method of confirming that a lump has been formed can be mentioned.

However, this method is expensive due to the use of an infrared sensor, and has problems such as leakage of high-pressure gas. Furthermore, since it is only necessary to determine whether the obtained powder is dense or sparse using an infrared sensor, it is difficult to distinguish whether a lump is formed or whether the powder is only dense. Was difficult to evaluate objectively.

The present invention has been made in view of the above situation, and accurately detects the formation of polymer lumps formed in a fluidized bed, and operates the fluidized bed reactor in accordance with the detection result. It is an object of the present invention to provide a gas-phase polymerization method and a gas-phase polymerization apparatus for controlling the temperature.

[0010]

In order to solve the above-mentioned problems, a gas-phase polymerization method according to the present invention supplies a solid catalyst for polymerization into a fluidized-bed reactor and uses a blower to lower the bottom of the fluidized-bed reactor. A gaseous monomer having a predetermined density is blown into a fluidized bed reactor through a dispersion plate to form a fluidized bed in the fluidized bed reactor, and the polymer is produced by a gas phase polymerization reaction in the fluidized bed. In producing the, by detecting the vibration of the fluidized bed reactor, a monitoring step of monitoring the state of lump formation in the fluidized bed reactor, based on the result, in the direction of suppressing lump formation Controlling the reaction conditions of the fluidized bed reactor.

In the monitoring step, the vibration energy obtained by detecting the vibration of the fluidized bed reactor is converted into electric energy, and when the electric energy has a predetermined magnitude, the lumps are formed. Is preferably determined to have occurred. Further, it is preferable to detect the vibration of the fluidized bed reactor using a piezoelectric element provided outside the fluidized bed reactor.

According to the above-mentioned gas-phase polymerization method, in the monitoring step, it is determined whether or not a lump is contained in the powdery polymer produced in the fluidized-bed reactor by using an appropriate determination means. In accordance with the result of this determination, the state of lump formation in the fluidized bed reactor is indirectly monitored. In the control step, based on the discrimination result obtained in the monitoring step, when the formation of lumps is confirmed, the reaction condition of the fluidized bed reactor is changed to a direction in which the formation of lumps is suppressed, for example, the amount of circulating gas (empty tower). Direction to improve the flow state by decreasing the powder level by increasing the speed), to reduce the partial pressure of olefin, to lower the polymerization temperature, to reduce the catalyst supply amount, etc. To control.

Further, as the above-mentioned appropriate discriminating means, for example, an electric detecting means, for example, a piezoelectric converter (such as a piezoelectric element),
When an electrostatic converter, a dynamic converter, or the like is used, a lump is detected as described below. As the mass is formed in the fluidized bed reactor, the mass moves vigorously in the fluidized bed. At that time, it is inserted into the inner wall of the fluidized bed reactor or the reactor and collides with a catalyst supply nozzle, a thermometer nozzle, and the like, which are provided integrally with the reactor. At this time, if lumps of a certain level (size, amount, etc.) or more are generated, the fluidized bed reactor will vibrate. This vibration energy is detected by, for example, electric detection means provided outside the fluidized bed reactor or the catalyst supply nozzle, the thermometer nozzle, or the like, and is converted into electric energy such as electric power, voltage, and current. When the converted electrical energy is greater than or equal to a predetermined amount, it is confirmed that a lump has been formed in the fluidized bed reactor.

In the gas-phase polymerization apparatus according to the present invention, a solid catalyst for polymerization is supplied into a fluidized-bed reactor, and a gaseous gas having a predetermined density is supplied from a bottom of the fluidized-bed reactor through a dispersion plate by a blower. Inject monomer into fluidized bed reactor,
A fluidized bed is formed in a fluidized bed reactor, and in a gas phase polymerization apparatus configured to obtain a polymer by a gas phase polymerization reaction in the fluidized bed, detecting means for detecting vibration of the fluidized bed reactor; And control means for controlling the reaction conditions of the fluidized-bed reactor in a direction to suppress lump formation based on the result detected by the detection means.

[0015] Further, the detecting means includes an electric detecting means for converting vibration energy obtained by detecting the vibration of the fluidized bed reactor into electric energy, and an electric energy obtained by the electric detecting means. It is preferable to have a determination means for determining whether or not is a predetermined size. Further, it is preferable that the electric detection means is a piezoelectric element provided outside the fluidized bed reactor.

According to the above-mentioned gas phase polymerization apparatus, the detecting means comprises:
It is detected whether or not lumps are contained in the powdery polymer formed in the fluidized-bed reactor, and the state of lumps detection in the fluidized-bed reactor is indirectly monitored according to the detection result. The control means, based on the detection result obtained by the detection means, when the formation of a lump is confirmed, changes the reaction condition of the fluidized bed reactor to a direction in which the formation of a lump is suppressed, for example, the amount of circulating gas (empty column) Direction to improve the flow state by decreasing the powder level by increasing the speed), to reduce the partial pressure of olefin, to lower the polymerization temperature, to reduce the catalyst supply amount, etc. To control.

In the case where, as the detecting means, for example, an electric detecting means, for example, a piezoelectric converter (such as a piezoelectric element), an electrostatic converter, an electrodynamic converter and the like and an appropriate discriminating means are used, Lumps are detected as follows. As the mass is formed in the fluidized bed reactor, the mass moves vigorously in the fluidized bed. At that time, it is inserted into the inner wall of the fluidized bed reactor or the reactor and collides with a catalyst supply nozzle, a thermometer nozzle, and the like, which are provided integrally with the reactor. At this time, if lumps above a certain level (size, amount, etc.) are generated,
The fluidized bed reactor will oscillate. This vibration energy is detected by, for example, electric detection means provided outside the fluidized bed reactor or the catalyst supply nozzle, the thermometer nozzle, or the like, and is converted into electric energy such as electric power, voltage, and current. When the converted electrical energy is greater than or equal to a predetermined amount, it is confirmed that lumps have been formed in the fluidized bed reactor.

As described in detail above, the detecting means for detecting vibration may be provided outside the reactor, for example, on the outer wall surface of the reactor, or inside the reactor, for example, a thermometer nozzle, for supplying a catalyst. You may arrange | position to the member inserted in the reactor, such as a nozzle. Above all, from the viewpoint of detecting the formation of lump sharply, it is desirable to dispose it on a member inserted into the reactor such as a thermometer nozzle or a catalyst supply nozzle. In other words, if the detection means is disposed on a member inserted into the reactor, relatively large vibration due to the collision of a relatively large mass and relatively small vibration due to the collision of a relatively small mass of normal particles can be obtained. However, since they are clearly distinguished, the formation of clumps can be detected more sharply. Further, since the influence of the vibration generated in the reactor due to factors other than the formation of the lump is small, the vibration generated by the formation of the lump can be detected more sharply.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a gas phase polymerization method according to the present invention and a gas phase polymerization apparatus to which the method is applied will be described in detail with reference to the drawings. In the present invention, "polymerization"
The term may be used to mean not only homopolymerization but also copolymerization, and the term "polymer"
It may be used in a meaning including not only a homopolymer but also a copolymer. Further, the gaseous monomer in the case of performing copolymerization refers to a mixture of a plurality of gaseous monomers.

FIG. 1 is a schematic diagram of a gas phase polymerization apparatus to which the gas phase polymerization method according to the present invention is applied. As shown in FIG.
The gas phase polymerization apparatus comprises a solid catalyst A for polymerization in a fluidized bed reactor 1.
And the blower 8 supplies the fluidized bed reactor 1
The gaseous monomer is blown into the fluidized-bed reactor 1 from the bottom through the gas dispersion plate 11 to form the fluidized bed 4 in the fluidized-bed reactor 1, and the gas-phase polymerization in the fluidized bed 4 is performed. It is configured to obtain a polymer or a copolymer by a reaction. Here, the gaseous monomer is one or more monomers (monomer, comonomer) polymerized by the action of the solid catalyst for polymerization.
The polymerization system may be supplied together with a molecular weight controlling agent such as hydrogen or an inert gas such as nitrogen or hydrocarbon.

In the above-mentioned gas-phase polymerization apparatus, the solid catalyst A is supplied into the fluidized-bed reactor 1 through the supply line 2, while the monomer such as gaseous olefin is supplied through the supply line 3. From the bottom of the fluidized bed reactor 1
Gas dispersion plate 11 made of a perforated plate or the like disposed near the bottom
The polymerization reaction is performed in the fluidized bed 4 while maintaining the fluidized bed (reaction system) 4 in a fluidized state. The gaseous monomer prepared in the raw material preparation section 21 is continuously supplied through a supply line 20 that joins the circulation line 7.

The powdery polymer (polymer powder) produced by the progress of the polymerization reaction in the fluidized bed 4 is continuously extracted from the fluidized bed reactor 1 through a line 5. . On the other hand, the unreacted gaseous monomer that has passed through the fluidized bed 4 has a reduced flow velocity in the deceleration region 6 provided in the upper part of the fluidized bed reactor 1 and is provided above the fluidized bed reactor 1. The gas is discharged out of the fluidized bed reactor 1 through the gas outlet 10A.

The unreacted monomer discharged from the fluidized bed reactor 1 needs to remove the heat of the polymerization reaction before it is blown into the fluidized bed 4 in the fluidized bed reactor 1 again. The heat is introduced into a heat exchanger (cooling device) 9 connected to the upstream side of the circulation line 7 and is cooled. The monomer gas cooled by the heat exchanger 9 is subsequently passed from the bottom of the fluidized-bed reactor 1 through a blower 8 and a supply line 3 disposed downstream of the circulation line 7 to a gas dispersion plate 11. Through the fluidized bed 4 in the fluidized bed reactor 1 again.

Here, if a polymer mass is formed in the fluidized bed reactor 1, the polymerization reaction performed in the fluidized bed 4 may not be efficiently performed. And a control means for controlling the reaction conditions of the fluidized bed reactor 1 in a direction to suppress the formation of lumps based on the result detected by the detecting means.
The reaction conditions inside are controlled.

As shown in FIG. 1, the control means includes an electric detection means 13 for converting vibration energy obtained by detecting vibration of the fluidized bed reactor 1 into electric energy, and an electric detection means 13. Determining section (sequencer) 1 for determining whether or not the electric energy obtained in step 1 has a predetermined magnitude
And preferably 4. The electrical detection means 13
Any device may be used as long as it converts vibration energy into electric energy such as electric power, current, and voltage, and outputs the electric energy as an electric signal.

As such an electric detecting means, a piezoelectric transducer using a piezoelectric element which generates an electric polarization of a magnitude depending on the magnitude of the stress when a stress is applied, and a statically charged piezoelectric transducer An electrostatic converter that consists of a fixed electrode and a movable electrode, and outputs a power proportional to the amplitude of the movable electrode by changing the capacitance between the two electrodes due to the vibration of the movable electrode. And a dynamic converter that generates an electromotive force depending on the amplitude of the coil.

Among them, it is preferable to use a piezoelectric transducer, especially a piezoelectric pickup, from the viewpoint of good measurement sensitivity and simple configuration. These electrical detection means
Both are inserted into the outer wall of the fluidized bed reactor 1 or into the fluidized bed reactor 1 and are disposed on a catalyst supply nozzle, a thermometer nozzle, etc. (not shown) integrally disposed with the reactor. By operating, in the case of a piezoelectric converter, the vibration of the reactor 1 is detected as a stress applied to the piezoelectric element, and in the case of an electrostatic converter, the vibration is detected as the movement of a movable electrode. Detects the vibration as deformation of the vibrating membrane, converts the vibration into electric energy of a magnitude corresponding to the detected vibration, and outputs an electric signal whose amplitude with respect to the detection time corresponds to the magnitude of the electric energy.

The discriminating section 14 discriminates whether or not the amplitude of the electric signal from the electric detecting means 13 is a predetermined magnitude.
A lump formation is detected in accordance with the determination result, and a control signal described later is sent to the monitoring and control unit (DCS) 15 when it is determined that the amplitude exceeds a predetermined magnitude. At this time,
Since the amplitude of the electric signal corresponds to the size of the lump, and the frequency at which the amplitude exceeds a predetermined size corresponds to the number of lump,
Based on this, the size and the number of lumps may be analyzed and determined. At this time, the electric signal may be subjected to predetermined processing, for example, waveform shaping, so that the electric signal becomes a signal suitable for analysis.

The monitoring and control unit 15 controls the operation of each member of the gas phase polymerization apparatus such as the catalyst supply line 2, the blower 8, the raw material preparation unit 21 and the peripheral equipment. The raw material preparation unit 21 prepares a gaseous monomer to be a raw material. When the gaseous monomer is a mixture of a plurality of gases, the output of each gas supply source is adjusted to prepare a gaseous monomer having a constant composition.

FIG. 2 shows a monitoring step (steps S1 to S4) and a control step (step S) in the gas phase polymerization method of the present invention.
A flowchart for explaining the main part of 5) is shown. Note that the monitoring step is a step performed by the electrical detection unit 13 and the determination unit 14, and the control step is a step performed by the monitoring and control unit 15.

In step S1, the energy of the vibration of the fluidized bed reactor 1 is detected by using an electrical detection means provided on the outer wall of the reactor 1, and the process proceeds to step S2. In step S2, the vibration energy detected in step S1 is converted into electric energy by the electric detection means to obtain an electric signal, and the process proceeds to step S3. This electrical signal
For example, it appears as a time change of the signal strength as shown in FIG.

In step S3, it is determined whether or not the magnitude of the electric energy, for example, the amplitude of the signal strength of the electric signal as shown in FIG. 3 is larger than a predetermined value, that is, a predetermined threshold value T. If the determination result is YES, that is, if the magnitude of the electric energy is larger than the threshold,
Proceed to step S4. If the determination result is NO, that is, if the magnitude of the electric energy is less than the threshold, the process returns to step S1. The threshold value is a value set in advance, but can be changed each time depending on the progress of the reaction.

In step S4, when it is determined in step S3 that the electric energy is larger than the predetermined value, peaks P ₁ and P ₂ are detected, and it is confirmed that lumps are formed in the polymer powder. Then, the process proceeds to step S5. In addition,
As described above, the size of the chunk may be analyzed and detected based on the amplitude of the electric signal, and the number of chunks may be detected based on the frequency of the amplitude exceeding a predetermined magnitude. That is, when the amplitude of the electric signal is large, the detected lump is large, and when the amplitude is small, the detected lump is small. Further, the frequency of the amplitude of the electric signal exceeding the threshold value increases as the frequency of occurrence of the chunks of the predetermined size increases, and decreases as the frequency decreases. In FIG. 3, the determination is made based on the magnitude of the distance F between the peaks. The frequency decreases as the value of the distance F increases, and the frequency increases as the value of the distance F decreases.

In any of the conventional methods, it is difficult to obtain data in which both are correlated. continue,
In step S5, it is determined in step S3 that the magnitude of the electric energy is larger than the predetermined magnitude, and in step S4
Monitoring and control unit 1 when a lump formation is detected in
Based on the operation of 5, the conditions of the polymerization reaction in the fluidized bed reactor 1 are changed in the direction of suppressing the formation of lumps, for example, by increasing the amount of circulating gas (superficial velocity) to reduce the flow state by reducing the powder level. The polymerization reaction is controlled in a direction that makes the polymerization reaction mild, such as a direction in which the polymerization is improved, a direction in which the partial pressure of the olefin is reduced, a direction in which the polymerization temperature is lowered, and a direction in which the amount of catalyst supplied is reduced.

For example, when reducing the partial pressure of the olefin, the monitoring and control unit 15 sends the raw material preparation unit 21 a predetermined partial gas of the gaseous monomer, such as ethylene, propylene, etc., to reduce the partial pressure of the gas. Control data to the effect. This control data is data indicating that the partial pressure of the predetermined monomer gas is reduced to a predetermined value,
It may be data indicating that the predetermined partial pressure of the monomer gas is to be continuously reduced until no lumps are detected. The raw material preparation unit 21 reduces the partial pressure of a predetermined monomer gas according to the control data.

For example, when the flow state is improved by increasing the amount of circulating gas (superficial velocity) to reduce the powder level, the monitoring and control unit 15 sends the blower 8
To the control data to change the rotation speed of the impeller. When a suction vane is provided on the suction side of the blower 8, the suction vane may be controlled so as to adjust the opening.

Here, the mode in which the control operation of step S5 is automatically performed has been described. However, the present invention is not limited to this.
Control operations may be manually added to the monitoring and control unit 15 or the like. In step S6, it is determined whether the polymerization is continued, that is, whether the generation of the polymer is further continued. further,
If the polymer generation is to be continued, return to step S1,
If not continued, the operation of the gas phase polymerization device is stopped and the process is terminated.

According to FIG. 2, the generation of the polymer powder is continued unless the magnitude and frequency of the electric energy are determined to be larger than the predetermined values in step S3. When it is detected that a lump having a predetermined size or more is mixed in the polymer powder (step S4), the operation of the fluidized bed reactor 1 is controlled so as to suppress lump formation. Note that in FIG. 2, only when lump generation is detected,
The continuation of the polymer production is required, and the flow of the polymer production is terminated, that is, the operation of the fluidized bed reactor 1 is stopped, but the operation of the fluidized bed reactor 1 is arbitrarily performed even when the generation of the lumps is not detected. Needless to say, it may be stopped.

The control itself may be performed automatically or manually. As described above, according to the gas phase polymerization method and the gas phase polymerization apparatus according to the present invention,
It does not directly monitor the condition in the fluidized bed reactor,
Appropriate detection means are provided on the outer wall of the fluidized bed reactor, a catalyst supply nozzle integrally provided with the reactor, a thermometer nozzle (for example, a reactor outer flange), and the like, so that the produced polymer powder is Since the detection of lumps is performed, there is no need to dispose special members inside the fluidized bed reactor, so there is no cost and there is no problem in terms of operational safety of the polymerization apparatus. Generation can be detected.

Further, monitoring the vibration of the fluidized bed reactor itself indirectly monitors the state in the fluidized bed reactor. Therefore, by detecting the formation of lumps in the produced polymer powder, It is possible to detect clump formation that accurately reflects the state in the fluidized bed. Therefore, it is possible to accurately detect the mass of the polymer formed in the fluidized bed, and to control the operation of the fluidized bed reactor according to such accurate information.

Further, as the detecting means for detecting the formation of the lumps in the polymer powder, it is possible to detect the formation of the lumps simply by adding a simple configuration using a simple electric detecting means and an appropriate discriminator. . Further, such a detection means may be disposed outside the reactor, for example, on the outer wall surface of the reactor, but inside the reactor, particularly a member inserted into the reactor, for example, a thermometer nozzle, for supplying a catalyst. It is desirable to arrange it on a supply line or the like.

FIG. 4 shows an embodiment in which an electric detection means 42 is provided on a thermometer nozzle 41 provided with a thermometer for monitoring the temperature of the fluidized bed of the fluidized bed reactor 1. The electric detection means 42 detects the vibration of the fluidized bed reactor 1 as the vibration of the thermometer nozzle, and converts the obtained vibration energy into electric energy in the same manner as the electric detection means 13. The energy is sent to the determination unit 14.

FIG. 5 shows an embodiment in which the electric detection means 51 is provided in the supply line 2 for supplying the catalyst to the fluidized bed 4 of the fluidized bed reactor 1. This electrical detection means 51
Detects the vibration of the fluidized-bed reactor 1 as the vibration of the supply line 2, converts the obtained vibration energy into electric energy in the same manner as the electric detection means 13, and outputs the electric energy to the determination unit 14. send.

As described above, if the electric detecting means as the detecting means is provided in the members inserted into the fluidized bed reactor 1, for example, the thermometer nozzle 41, the supply line 2, etc., the relatively large mass Since the relatively large vibration caused by the impact of a normal particle having a relatively small mass and the relatively small vibration caused by the impact of a normal particle having a relatively small mass are clearly distinguished from each other, the formation of a lump can be detected more sharply. In addition, since the influence of the vibration generated in the fluidized bed reactor 1 by a factor other than the formation of the lump is small, the vibration generated by the formation of the lump can be detected more sharply.

Although the preferred embodiment of the present invention has been described above, the present invention is not limited to this, and various modifications can be made without departing from the object of the present invention.

[0046]

According to the gas-phase polymerization method and the gas-phase polymerization apparatus of the present invention, it is not necessary to dispose a special member inside a commonly used fluidized bed reactor. Lump formation can be detected simply by adding a simple member outside the bed reactor. In addition, since lump detection can be performed by accurately reflecting the state in the fluidized bed, it is possible to accurately grasp the state in the fluidized bed and to control the operation of the fluidized bed reactor based on accurate information. Becomes possible.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a main part of a gas phase polymerization apparatus according to the present invention.

FIG. 2 is a flowchart for explaining a gas phase polymerization method according to the present invention.

FIG. 3 is a diagram showing a time change of the signal intensity of an electric signal detected by the gas phase polymerization apparatus according to the present invention.

FIG. 4 is a schematic diagram showing another embodiment of the gas-phase polymerization apparatus according to the present invention, in which a detection means is provided on a thermometer nozzle inserted into a reactor.

FIG. 5 is a schematic view showing another embodiment of the gas-phase polymerization apparatus according to the present invention, in which the detection means is provided in a catalyst supply nozzle inserted into the reactor.

FIG. 6 is a schematic view showing a main part of a conventional gas phase polymerization apparatus.

[Description of Signs] 1 Fluidized bed reactor 4 Fluidized bed (reaction system) 8 Blower 11 Gas dispersion plate 13 Electrical detection means 14 Discriminator (sequencer) 15 Monitoring and control unit 21 Raw material preparation unit 41 Thermometer nozzle 42, 51 Electrical detection means

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Tomohiro Arase 3 Chigusa Kaigan, Ichihara-shi, Chiba Prefecture Mitsui Chemicals, Inc. 72) Inventor Kohei Iwazuki 3 Chigusa Beach, Ichihara City, Chiba Prefecture Mitsui Chemical Engineering Co., Ltd. F term (reference) 4J011 AB10 AB11 DB33 MA02 MA14 MA17 MB01

Claims (6)

[Claims] 1. A solid catalyst for polymerization is supplied into a fluidized-bed reactor, and a gaseous monomer having a predetermined density is introduced into the fluidized-bed reactor from a bottom of the fluidized-bed reactor by a blower through a dispersion plate. Blowing to form a fluidized bed in the fluidized bed reactor,
When producing a polymer by a gas phase polymerization reaction in the fluidized bed, by monitoring the vibration of the fluidized bed reactor, a monitoring step of monitoring the state of mass formation in the fluidized bed reactor, A control step of controlling the reaction conditions of the fluidized bed reactor in a direction to suppress lump formation based on the result. 2. In the monitoring step, the vibration energy obtained by detecting the vibration of the fluidized-bed reactor is converted into electric energy, and when the electric energy becomes equal to or larger than a predetermined value, the mass is increased. The gas phase polymerization method according to claim 1, wherein it is determined that generation has occurred. 3. The gas-phase polymerization method according to claim 2, wherein the vibration of the fluidized-bed reactor is detected using a piezoelectric element provided outside the fluidized-bed reactor. 4. A solid catalyst for polymerization is supplied into the fluidized-bed reactor, and a gaseous monomer having a predetermined density is supplied from the bottom of the fluidized-bed reactor through a dispersion plate into the fluidized-bed reactor by a blower. Blowing to form a fluidized bed in the fluidized bed reactor,
In a gas phase polymerization apparatus configured to obtain a polymer by a gas phase polymerization reaction in the fluidized bed, detecting means for detecting vibration of the fluidized bed reactor, based on a result detected by the detecting means Control means for controlling the reaction conditions of the fluidized-bed reactor in a direction to suppress lump formation. 5. The electric detection means for converting vibration energy obtained by detecting the vibration of the fluidized-bed reactor into electric energy, the electric energy obtained by the electric detection means. The gas phase polymerization apparatus according to claim 4, further comprising: a determination unit configured to determine whether or not is a predetermined size. 6. The gas phase polymerization apparatus according to claim 5, wherein the electric detection means is a piezoelectric element provided outside the fluidized bed reactor.