CN108201864A - A rotary feeder for polyolefin solid catalyst - Google Patents

Abstract

A rotary feeder of a solid polyolefin catalyst, the rotary feeder comprising: the shell is internally provided with a cavity; the cylinder is transversely arranged, a circle of groove is formed in the surface of the cylinder, the cylinder is arranged in the cavity, is tightly attached to the cavity and can roll around an axis in the cavity; and the connecting shaft is arranged on the axis of the cylinder, a hole is formed in the position, corresponding to the connecting shaft, of the shell, and the connecting shaft penetrates through the hole. The rotary feeder equipment is simple in structure and convenient to maintain. The solid polyolefin catalyst particles according to the present invention can be continuously, smoothly and accurately fed into the polymerization reactor.

Description

A rotary feeder for polyolefin solid catalyst

technical field

The invention relates to the field of olefin polymerization, in particular to a feeder for granular solid polyolefin catalysts.

Background technique

At present, most of the catalysts used in olefin polymerization in industry are solid particle type, and the feeding of this solid particle type catalyst is usually added by a specially designed catalyst feeding device, such as the solid catalyst feeding device adopted on the Unipol polyethylene device; there is also a After a complex preparation process, the catalyst is prepared into a certain concentration of slurry or paste, and then sent into the reactor with a metering system. In the above two methods, the equipment investment of the former is very high, the adding process is easy to block, and there is no accurate and effective method to know the catalyst content in the catalyst feeder. The preparation process of the latter is extremely complicated, and the preparation of a single catalyst requires more than ten hours, and the catalyst brings the slurry or paste into the reaction system, which has an impact on the reaction system.

Polyolefin catalysts usually have high activity. In actual operation, the catalyst is required to be added to the polymerization reactor at a very stable and precisely controlled very small flow rate, otherwise the polymerization reaction will be unstable, resulting in fluctuations in product quality or in the reactor. of agglomerates. Therefore, how to uniformly and accurately add the catalyst to the polymerization reaction system is a key problem to be solved. In addition, the fluidity of the solid olefin polymerization catalyst is poor, and it is easy to stick together or form bridges in the catalyst tank. The catalyst cannot be added to the feed pipeline through the automatic valve, resulting in the inability to feed the catalyst continuously and the reaction is forced to stop.

Chinese patent CN101786552A discloses an automatic metering feeder for powder materials, including a feeding funnel, the outlet of the feeding funnel is connected to the inlet of the metering ball valve, and the material channel of the metering ball valve is provided with a storage room with a certain capacity and can rotate. The outer wall of the valve is close to the inner wall of the material channel of the metering ball valve. During the rotation of the storage chamber, the material inlet and outlet can be connected with the inlet or outlet of the metering ball valve. The invention can realize small-dose powder feeding, but the material is easy to deposit on the inner wall of the material channel, causing metering errors.

Chinese patent CN101811011A discloses a catalyst automatic feeding method. The fluidization conveying air pipeline is set to continuously feed the fluidizing conveying air into the feeder. A fluidizing conveying air regulating valve and a flow meter are arranged on the fluidizing conveying air pipeline. Feeding regulating valve, a connecting pipe is set between the top of the feeder and the pipe section of the discharge pipe near the outlet of the discharge valve. , the catalyst circulates in the connected circulation loop at the top of the feeder, which reduces the deposition and clogging during the catalyst delivery process, and the problem of unstable feeding, but the circulation device of this equipment is set on the top of the feeder, and strong fluidization is required during the circulation process Conveying air, the device generally uses compressed air as the fluidized conveying air, so the equipment cost is relatively high, and the invention also requires the fluidized conveying air to ensure that the internal pressure of the feeder is constantly lower than or equal to the catalyst tank charging pressure and higher than the regeneration pressure. The pressure of the device is higher, so the requirements for the equipment are higher, and the production cost is increased.

Chinese patent CN102993342 A provides a feeding system for powdery polyolefin catalyst. The system includes a catalyst tank, an intermediate tank and a fan. The catalyst tank is connected to the intermediate tank through a pipeline. An automatic valve is set on the pipeline. The inlet and outlet of the fan are respectively connected to the top and bottom of the intermediate tank by pipelines to form a circulation loop. The top position is provided with an outlet, which is connected with the rear system through pipelines. Two automatic valves connected in series are arranged on the system pipeline connected with the rear system, and a quantitative tube is arranged between the automatic valves; a gas purge pipeline is respectively arranged at the outlets of the two automatic valves. The invention can continuously add the solid catalyst into the reaction system under normal pressure, but due to the lack of a metering device for the catalyst, the amount of the catalyst added cannot be controlled. Moreover, this feeding system adopts a catalyst tank and an intermediate tank, the catalyst feeding process is long, and the catalyst is easy to accumulate and remain in the intermediate tank, resulting in waste of catalyst.

At present, there is a lack of a catalyst feeder that is simple in equipment structure, easy to repair and maintain, and capable of continuously, stably and accurately feeding solid polyolefin catalyst particles into a polymerization reactor.

Contents of the invention

The object of the present invention is to provide a rotary feeder for polyolefin solid catalyst.

To achieve the above object, the invention provides a rotary feeder for polyolefin solid catalyst, said feeder comprising:

A shell, a cavity is formed inside the shell;

A cylinder, the cylinder is arranged laterally, the surface of the cylinder is provided with a circle of grooves, the cylinder is arranged in the cavity and fits closely with the cavity and can rotate around the axis in the cavity scroll; and

A connection shaft, the connection shaft is arranged on the axis of the cylinder, a hole is provided on the housing corresponding to the position of the connection shaft, and the connection shaft passes through the hole.

Further, the space above and below the cavity is always in communication with the groove. Catalyst is continuously fed into the groove, and can be continuously fed through the groove as the cylinder rotates.

Further, the groove is slope-shaped. The size and shape of the groove directly affect the continuous feeding, precise metering and control of the catalyst. The groove on the surface of the cylinder is in the shape of a concave slope, which is conducive to the continuous entry of the catalyst into the groove, and is more conducive to passing through the groove with the rotation of the cylinder Continuous feeding.

Further, the angle between the groove and the axis is greater than 0° and less than 90°, preferably greater than 15° and less than 75°, more preferably greater than 30° and less than 60°. There is a certain angle between the groove and the axis, which makes it easier to control the feeding speed and amount of the catalyst.

Further, the surface of the cavity, the surface of the cylinder and the surface of the groove are all smooth surfaces. The smooth surface of the cylinder is conducive to the sealing between the cylinder and the surface of the cavity, and the smooth surface of the groove is conducive to the feeding of the catalyst, effectively preventing the residue of the catalyst in the groove, and is conducive to the precise measurement and control of the catalyst feeding .

The beneficial effects of the invention are: the feeder has a simple structure and can continuously, steadily and accurately feed the solid polyolefin catalyst particles into the polymerization reactor, which not only saves the production cost of polyolefin, but also facilitates equipment maintenance.

Description of drawings

Fig. 1 is a structural schematic diagram of a feeder for a polyolefin solid catalyst according to the present invention.

Fig. 2 is a cross-sectional view of the cylinder in the feeder of the polyolefin solid catalyst according to the present invention.

Among them, reference signs:

1. Shell

2. Cylinder

3. Groove

4. Connecting shaft

α, included angle

Detailed ways

The present invention is described in detail by the following examples. It is necessary to point out that this example is only used to further illustrate the present invention, and can not be interpreted as limiting the protection scope of the present invention. Make corresponding non-essential improvements and adjustments.

A kind of rotary feeder of polyolefin solid catalyst, described feeder comprises:

A shell 1, a cavity is formed inside the shell 1;

A cylinder 2, the cylinder 2 is arranged laterally, the surface of the cylinder 2 is provided with a circle of grooves 3, the cylinder 2 is arranged in the cavity and fits closely with the cavity and can rolling around the axis within the cavity; and

A connecting shaft 4, the connecting shaft 4 is arranged on the axis of the cylinder 2, a hole is provided on the housing 1 corresponding to the position of the connecting shaft 4, and the connecting shaft 4 passes through the hole.

Further, the space above and below the cavity is always in communication with the groove 3 . The catalyst enters the groove 3 continuously, and can be fed continuously through the groove 3 as the cylinder 2 rotates.

Further, the groove 3 is slope-shaped. The size and shape of the groove 3 directly affect the continuous feeding, precise metering and control of the catalyst. The groove 3 on the surface of the cylinder 2 is in the shape of a concave slope, which is conducive to the continuous entry of the catalyst into the groove 3, and is more conducive to 2 Rotate through the groove for continuous feeding.

Further, the angle α between the groove 3 and the axis is greater than 0° and less than 90°, preferably greater than 15° and less than 75°, more preferably greater than 30° and less than 60°. There is a certain angle between the groove 3 and the axis, which makes it easier to control the feeding speed and amount of the catalyst.

Further, the surface of the cavity, the surface of the cylinder 2 and the surface of the groove 3 are all smooth surfaces. The smoothness of the surface of the cylinder 2 is conducive to the sealing between the cylinder 2 and the surface of the cavity, and the smoothness of the surface of the groove 3 is conducive to the feeding of the catalyst, which effectively prevents the residue of the catalyst in the groove 3 and is conducive to the removal of the catalyst. Precise metering and control.

Example 1

The angle α between the direction of the groove 3 on the surface of the cylinder 2 and the axis is determined to be 15°C, and the different rotation speeds of the cylinder 2 are accurately measured and calibrated with the exhausted Ti-based catalyst. The specific process is that the cylinder 2 Rotation speed is set to 2 rpm, 4 rpm, 6 rpm, 7 rpm, 8 rpm, 9 rpm, 10 rpm, 12 rpm, 14 rpm , 16 rpm, 20 rpm, 30 rpm, measure the amount of catalyst feed in 5 minutes, 10 minutes, 15 minutes, 30 minutes, and 1 hour, and take the average value, and then draw the catalyst The relationship curve between the feeding amount and the rotation speed of the cylinder 2, and determine its relationship formula. Obtain the relational curve or relational expression of this kind of catalyst feeding amount and cylinder 2 rotation speeds, determine that can by adjusting the rotation speed of cylinder 2, carry out accurate metering and control to catalyst feeding amount, the rotation of cylinder 2 is driven by motor controlling.

Example 2

The included angle α between the direction of a circle of grooves 3 on the surface of the cylinder 2 and the axis is determined to be 20°C, and the different rotation speeds of the cylinder 2 are accurately measured and calibrated by using an invalid Cr-based catalyst. Rotation speed is set to 2 rpm, 4 rpm, 6 rpm, 7 rpm, 8 rpm, 9 rpm, 10 rpm, 12 rpm, 14 rpm , 16 rpm, 20 rpm, 30 rpm, measure the amount of catalyst feed in 5 minutes, 10 minutes, 15 minutes, 30 minutes, and 1 hour, and take the average value, and then draw the catalyst The relationship curve between the feeding amount and the rotation speed of the cylinder 2, and determine its relationship formula. Obtain the relational curve or relational expression of this kind of catalyst feeding amount and cylinder 2 rotation speeds, confirm that can now by adjusting the rotation speed of cylinder 2, carry out accurate metering and control to catalyst feeding amount, the rotation of cylinder 2 is controlled by an electric motor.

Example 3

The angle α between the direction of the groove 3 on the surface of the cylinder 2 and the axis is determined to be 30°C, and the different rotation speeds of the cylinder 2 are accurately measured and calibrated with the spent metallocene catalyst. Rotation speed is set to 2 rpm, 4 rpm, 6 rpm, 7 rpm, 8 rpm, 9 rpm, 10 rpm, 12 rpm, 14 rpm , 16 rpm, 20 rpm, 30 rpm, measure the amount of catalyst feed in 5 minutes, 10 minutes, 15 minutes, 30 minutes, and 1 hour, and take the average value, and then draw the catalyst The relationship curve between the feeding amount and the rotation speed of the cylinder 2, and determine its relationship formula. Obtain the relational curve or relational expression of this kind of catalyst feeding amount and cylinder 2 rotation speeds, confirm that can now by adjusting the rotation speed of cylinder 2, carry out accurate metering and control to catalyst feeding amount, the rotation of cylinder 2 is controlled by an electric motor.

Example 4

The angle α between the direction of a circle of grooves 3 on the surface of the cylinder 2 and the axis is determined to be 40°C, and the different rotation speeds of the cylinder 2 are accurately measured and calibrated with an invalid metallocene catalyst. The specific process is that the cylinder 2 Rotation speed is set to 2 rpm, 4 rpm, 6 rpm, 7 rpm, 8 rpm, 9 rpm, 10 rpm, 12 rpm, 14 rpm , 16 rpm, 20 rpm, 30 rpm, measure the amount of catalyst feed in 5 minutes, 10 minutes, 15 minutes, 30 minutes, and 1 hour, and take the average value, and then draw the catalyst The relationship curve between the feeding amount and the rotation speed of the cylinder 2, and determine its relationship formula. Obtain the relational curve or relational expression of this kind of catalyst feeding amount and cylinder 2 rotation speeds, confirm that can now by adjusting the rotation speed of cylinder 2, carry out accurate metering and control to catalyst feeding amount, the rotation of cylinder 2 is controlled by an electric motor.

Example 5

The included angle α between the direction of a circle of grooves 3 on the surface of the cylinder 2 and the axis is determined to be 50°C, and the different rotation speeds of the cylinder 2 are accurately measured and calibrated with an invalid Cr-based catalyst. Rotation speed is set to 2 rpm, 4 rpm, 6 rpm, 7 rpm, 8 rpm, 9 rpm, 10 rpm, 12 rpm, 14 rpm , 16 rpm, 20 rpm, 30 rpm, measure the amount of catalyst feed in 5 minutes, 10 minutes, 15 minutes, 30 minutes, and 1 hour, and take the average value, and then draw the catalyst The relationship curve between the feeding amount and the rotation speed of the cylinder 2, and determine its relationship formula. Obtain the relational curve or relational expression of this kind of catalyst feeding amount and cylinder 2 rotation speeds, confirm that can now by adjusting the rotation speed of cylinder 2, carry out accurate metering and control to catalyst feeding amount, the rotation of cylinder 2 is controlled by an electric motor.

Example 6

The angle α between the direction of a circle of grooves 3 on the surface of the cylinder 2 and the axis is determined to be 60°C, and the different rotation speeds of the cylinder 2 are accurately measured and calibrated with an invalid Cr-based catalyst. Rotation speed is set to 2 rpm, 4 rpm, 6 rpm, 7 rpm, 8 rpm, 9 rpm, 10 rpm, 12 rpm, 14 rpm , 16 rpm, 20 rpm, 30 rpm, measure the amount of catalyst feed in 5 minutes, 10 minutes, 15 minutes, 30 minutes, and 1 hour, and take the average value, and then draw the catalyst The relationship curve between the feeding amount and the rotation speed of the cylinder 2, and determine its relationship formula. Obtain the relational curve or relational expression of this kind of catalyst feeding amount and cylinder 2 rotation speeds, confirm that can now by adjusting the rotation speed of cylinder 2, carry out accurate metering and control to catalyst feeding amount, the rotation of cylinder 2 is controlled by an electric motor.

Example 7

It is determined that the angle α between the direction of a circle of grooves 3 on the surface of the cylinder 2 and the axis is 65°C, and the different rotation speeds of the cylinder 2 are accurately measured and calibrated with the exhausted Ti-based catalyst. The specific process is that the cylinder 2 Rotation speed is set to 2 rpm, 4 rpm, 6 rpm, 7 rpm, 8 rpm, 9 rpm, 10 rpm, 12 rpm, 14 rpm , 16 rpm, 20 rpm, 30 rpm, measure the amount of catalyst feed in 5 minutes, 10 minutes, 15 minutes, 30 minutes, and 1 hour, and take the average value, and then draw the catalyst The relationship curve between the feeding amount and the rotation speed of the cylinder 2, and determine its relationship formula. Obtain the relational curve or relational expression of this kind of catalyst feeding amount and cylinder 2 rotation speeds, confirm that can now by adjusting the rotation speed of cylinder 2, carry out accurate metering and control to catalyst feeding amount, the rotation of cylinder 2 is controlled by an electric motor.

Example 8

Determined that the angle α between the direction of a circle of grooves 3 on the surface of the cylinder 2 and the axis is 75°C, and the different rotation speeds of the cylinder 2 were accurately measured and calibrated with the exhausted Ti-based catalyst. Rotation speed is set to 2 rpm, 4 rpm, 6 rpm, 7 rpm, 8 rpm, 9 rpm, 10 rpm, 12 rpm, 14 rpm , 16 rpm, 20 rpm, 30 rpm, measure the amount of catalyst feed in 5 minutes, 10 minutes, 15 minutes, 30 minutes, and 1 hour, and take the average value, and then draw the catalyst The relationship curve between the feeding amount and the rotation speed of the cylinder 2, and determine its relationship formula. Obtain the relational curve or relational expression of this kind of catalyst feeding amount and cylinder 2 rotation speeds, confirm that can now by adjusting the rotation speed of cylinder 2, carry out accurate metering and control to catalyst feeding amount, the rotation of cylinder 2 is controlled by an electric motor.

The feeder of the present invention does not need to calibrate each catalyst, but needs to be calibrated once accurately, and the added mass of the catalyst can be calculated through the volume flow rate and the density of the catalyst. Thus, it is shown that the feeder using the solid polyolefin catalyst of the present invention is a catalyst feeder with simple equipment structure and can continuously, smoothly and accurately feed the solid polyolefin catalyst particles into the polymerization reactor. The feeder not only saves the production cost of polyolefin, but also facilitates the repair and maintenance of equipment.

Certainly, the present invention also can have other various embodiments, without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and deformations according to the present invention, but these corresponding changes All changes and modifications should belong to the protection scope of the claims of the present invention.

Claims (7)

1. a kind of Rotary feeder of solid polyolefin hydrocarbon catalyst, which is characterized in that the Rotary feeder includes：

One shell, the enclosure are formed with a cavity；

One cylinder, the cylinder are laterally set, and the periphery is equipped with a circle groove, and the cylinder is set on described It fits closely and can be rolled in the cavity around axis in cavity and with the cavity；And

One connecting shaft, the connecting shaft are set on the axis of cylinder, and the position on the shell corresponding to the connecting shaft is set There is a hole, the connecting shaft passes through the hole.

2. the Rotary feeder of solid polyolefin hydrocarbon catalyst according to claim 1, which is characterized in that the cavity it is upper Side is communicated with underlying space with the groove always.

3. the Rotary feeder of solid polyolefin hydrocarbon catalyst according to claim 1, which is characterized in that the groove is slope Shape.

4. the Rotary feeder of solid polyolefin hydrocarbon catalyst according to claim 1, which is characterized in that the groove and axis The angle of line is more than 0 ° and less than 90 °.

5. the Rotary feeder of solid polyolefin hydrocarbon catalyst according to claim 1, which is characterized in that the groove and axis The angle of line is more than 15 ° and less than 75 °.

6. the Rotary feeder of solid polyolefin hydrocarbon catalyst according to claim 1, which is characterized in that the groove and axis The angle of line is more than 30 ° and less than 60 °.

7. the Rotary feeder of solid polyolefin hydrocarbon catalyst according to claim 1, which is characterized in that the cavity table Face, periphery and groove surfaces are smooth surface.