A continuous or intermittent automatic precise catalyst conveying device and method

Abstract

The present application belongs to the technical field of feeding equipment, and particularly relates to a continuous or intermittent automatic precise catalyst conveying device, which comprises a fluidization tank, a partition plate is fixed in the fluidization tank, and the fluidization tank is evenly divided into multiple cavities by the partition plate; a fluidization air inlet pipeline is connected to the bottom of each cavity; a metering barrel is fixed in each cavity, a feeding pipeline is connected to the top of each metering barrel, a catalyst storage tank is connected to each metering barrel through the feeding pipeline, a discharge pipeline is connected to each metering barrel, and multiple metering barrels are jointly connected to a reactor through the discharge pipelines. Through the automatic control, weighing feeding and fluidization conveying arrangement, the problems that the feeding device cannot continuously feed, the metering is not accurate, and the feeding device is prone to failure during feeding are solved.

Description

Technical Field

[0001] This invention belongs to the technical field of feeding equipment, and particularly relates to a continuous or intermittent automatic and precise catalyst conveying device and method. Background Technology

[0002] In recent years, the technology of polyolefin catalysts has developed rapidly, and their catalyst activity has been continuously improved. More and more polymerization units need to accurately measure the amount of catalyst added in order to improve the efficiency of polymerization reaction.

[0003] Currently, for reactions requiring prepolymerization, the common method for adding catalyst to the prepolymerization reactor is to connect a small stainless steel catalyst feeding tank to the top of the reactor lid. This is done manually, by connecting a weighed catalyst glass tube to the top of the catalyst feeding tank using a latex tube. Under a slight positive pressure, the catalyst is added to the catalyst feeding tank using an additive. Therefore, manual operation requires extremely precise pressure regulation of the nitrogen positive pressure protective gas. Improper operation can cause the catalyst glass tube connected by the latex tube to break, resulting in catalyst leakage and environmental pollution. Furthermore, this feeding method is very likely to leave catalyst residue at the upper feeding port of the catalyst feeding tank, leading to inaccurate catalyst feeding and affecting the normal operation of subsequent processes.

[0004] For polymerization reactions requiring the direct addition of dry powder catalysts, such as the gas-phase production of polyethylene, grinding conveyors are generally used, such as those from Mark V, Amoco, and the Beijing Aerospace Propulsion Research Institute. However, grinding conveyors are prone to malfunctions, with frequent catalyst blockages, leading to poor overall system stability, low load, uncontrolled product quality, high energy and material consumption, and high labor intensity for employees. Furthermore, Mark V conveyors and similar systems are mechanical feeding systems with motor-driven agitation, resulting in complex structures, difficult operation and maintenance, and high investment and operating costs. Moreover, grinding conveyors rely on the isochoric method, combining rotational speed to calculate the feed rate, which is less accurate and reliable than the weighing method.

[0005] For feeding devices that use weighing to measure, intermittent feeding is generally used, and continuous feeding is basically impossible. Summary of the Invention

[0006] Based on the technical problems existing in the background art, the present invention provides a catalyst continuous or intermittent automatic precision conveying device and method. By setting up automatic control, weighing feeding and fluidized conveying, the problems of feeding device being unable to feed continuously, inaccurate metering and easy failure of feeding device are solved.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] This invention claims a continuous or intermittent automatic precision catalyst delivery device, comprising a fluidizing tank, wherein a partition plate is fixed inside the fluidizing tank, the partition plate dividing the fluidizing tank into multiple chambers; a fluidizing air inlet pipeline is connected to the bottom of each chamber; a metering tank is fixed inside each chamber, a feeding pipeline is connected to the top of each metering tank, each metering tank is connected to a catalyst storage tank through the feeding pipeline, and a discharge pipeline is connected to each metering tank; the multiple metering tanks are connected to a reactor through the discharge pipeline.

[0009] The fluidizing tank is equipped with multiple weighing sensors. Some of the weighing sensors are fixed to the inner wall of the fluidizing tank, and others are fixed to the side wall of the partition plate. All the weighing sensors are located around the bottom wall of the metering barrel, and all the weighing sensors are electrically connected to the air valve control component.

[0010] Preferably, each feeding pipeline is equipped with a feeding valve and a shut-off valve in sequence, with the shut-off valve located upstream of the feeding valve; each discharging pipeline is equipped with a discharging valve, and each fluidizing air inlet pipeline is equipped with an air inlet valve. Each feeding valve, discharging valve, and air inlet valve is electrically connected to the air valve control assembly.

[0011] Preferably, the air valve control assembly includes a controller, the controller being electrically connected to a solenoid valve group, the solenoid valve group being connected to an instrument air supply pipeline, and an instrument air valve being installed on the instrument air supply pipeline; the solenoid valve group is electrically connected to each feeding valve, discharging valve, and inlet valve respectively.

[0012] Preferably, the bottom plate of the metering barrel is a gas distribution plate.

[0013] Preferably, the feeding pipeline located in each cavity is connected to the top of the corresponding metering barrel; the discharging pipeline located in each cavity is connected to the bottom of the corresponding metering barrel; and the inner diameter of the feeding pipeline is larger than the inner diameter of the discharging pipeline.

[0014] This invention also claims a method for continuous or intermittent automatic and precise delivery of a catalyst, comprising the following steps:

[0015] S1: Open the instrument air valve to connect the instrument air, and at the same time open multiple shut-off valves. The catalyst in multiple catalyst storage tanks enters the feeding pipeline before the feeding valve by its own gravity. Connect the power supply of the controller, and the controller starts to run, dividing the multiple chambers into the first chamber and the second chamber.

[0016] S2: Catalyst is introduced into the metering tank in the first cavity. The controller obtains the value of the weighing sensor of each metering tank in the first cavity. After reaching the preset value, the introduction is stopped. Catalyst is introduced into the metering tank in the second cavity. The controller obtains the value of the weighing sensor of each metering tank in the second cavity. After reaching the preset value, the introduction is stopped and the tank is ready for use.

[0017] S3: Fluidizing air is introduced into the first cavity to fluidize the catalyst in each metering tank of the first cavity. After reaching the preset pressure value, the catalyst in the metering tank of the first cavity is sent to the reactor through the connected discharge pipeline. During the discharge process of the metering tank of the first cavity, fluidizing air is introduced into the second cavity to fluidize the catalyst in each metering tank of the second cavity. After reaching the preset pressure value, fluidization is stopped and the catalyst is ready for use.

[0018] S4: Catalyst is introduced into the metering tank in the first cavity. The controller obtains the value of the weighing sensor of each metering tank in the first cavity. After reaching the preset value, the introduction is stopped. The catalyst in the metering tank of the second cavity is sent to the reactor through the connected discharge pipeline. During the discharge process of the metering tank in the second cavity, fluidizing air is introduced into the first cavity to fluidize the catalyst in each metering tank in the first cavity. After reaching the preset pressure value, the fluidization is stopped and the catalyst is ready for use.

[0019] S5: Catalyst is introduced into the metering tank in the second part of the cavity. The controller obtains the value of the weighing sensor of each metering tank in the second part of the cavity. After reaching the preset value, the introduction is stopped. The catalyst in the metering tank of the first part of the cavity is sent to the reactor through the connected discharge pipeline. During the discharge process of the metering tank in the first part of the cavity, fluidizing air is introduced into the second part of the cavity to fluidize the catalyst in each metering tank in the second part of the cavity. After reaching the preset pressure value, the fluidization is stopped and the catalyst is ready for use.

[0020] S6: Repeat operations S4 to S5.

[0021] Preferably, in S1, both the fluidizing air and the instrument air are made of nitrogen or an inert gas.

[0022] Preferably, in S2, S4 and S5, the preset value of the weighing sensor is 10 to 200 kg.

[0023] Preferably, in S3 to S5, the pressure value of the fluidizing air for fluidization is 0.1 to 1.0 MPa greater than the target reactor back pressure value.

[0024] Preferably, in S2 to S5, the first partial cavity includes at least one cavity, and the second partial cavity includes at least one cavity.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] (1) The conveying device and method of the present invention adopts an instrument air source and controls the opening and closing of the feeding valve, the discharging valve and the fluidizing air valve by controlling the electromagnetic valve group. The structure is simple and can be automatically controlled, eliminating the tedious operation of manual feeding. The weighing sensor is used to monitor the feeding amount in real time, and the weighing error is ≤1%, which is highly accurate and overcomes the defect of inaccurate metering of existing feeding methods. Furthermore, the fluidizing air source is used to first fluidize the catalyst in the metering tank. After sufficient fluidization, it is connected to the reactor, which avoids the incomplete discharge of the catalyst in the metering tank and the occurrence of device blockage. This improves the stability of device operation and ensures the quality of the product. The device has a simple and ingenious structure.

[0027] (2) The conveying method of the present invention, by adding the catalyst fluidized in the second part of the chamber to the reactor when the catalyst is added to the metering tank in the first part of the chamber for fluidization, and by adding the catalyst fluidized in the first part of the chamber to the reactor when the catalyst is added to the metering tank in the second part of the chamber for fluidization, the two steps are repeated to realize the continuous automatic feeding of the catalyst, overcome the defect that the weighing feeding method cannot achieve continuous and uninterrupted feeding, and can also choose to perform intermittent automatic feeding. The operation method is simple and has a low failure rate. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the overall structure of a catalyst continuous or intermittent automatic precision delivery device according to the present invention.

[0029] The components include: 1. Catalyst storage tank; 2. Shut-off valve; 3. Feed valve; 4. Feeding pipeline; 5. Discharge pipeline; 6. Discharge valve; 7. Fluidizing tank; 8. Metering tank; 9. Weighing sensor; 10. Cavity; 12. Divider plate; 13. Fluidizing air inlet pipeline; 14. Inlet valve; 22. Reactor; 27. Controller; 28. Solenoid valve assembly; 29. ​​Instrument air valve; 30. Instrument air pipeline. Detailed Implementation

[0030] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention. Furthermore, the embodiments and features in the embodiments of the present invention can be combined with each other without conflict.

[0031] Example 1

[0032] like Figure 1As shown, a continuous or intermittent automatic precision catalyst delivery device includes a fluidizing tank 7, a partition plate 12 fixed inside the fluidizing tank 7, the partition plate 12 dividing the fluidizing tank 7 into multiple chambers 10; a fluidizing air inlet pipeline 13 is connected to the bottom of each chamber 10; a metering tank 8 is fixed inside each chamber 10, a feeding pipeline 4 is connected to the top of each metering tank 8, a catalyst storage tank 1 is connected to each metering tank 8 through the feeding pipeline 4, a discharge pipeline 5 is connected to each metering tank 8, and multiple metering tanks 8 are connected to a reactor 22 through the discharge pipeline 5.

[0033] The fluidizing tank 7 is equipped with multiple weighing sensors 9. Some of the weighing sensors 9 are fixed on the inner wall of the fluidizing tank 7, and the other part is fixed on the side wall of the partition plate 12. All the weighing sensors 9 are located around the bottom wall of the metering barrel 8, and all the weighing sensors 9 are electrically connected to the air valve control component.

[0034] The fluidizing tank 7 is cylindrical in the middle, with the upper end connected to the upper head and the lower end connected to the lower head. The partition plate 12 is located in the middle of the fluidizing tank 7. The top of the metering tank 8 is flush with the lower surface of the upper head of the fluidizing tank 7. The catalyst storage tank 1 is used to store the catalyst. The catalyst storage tank 1 adds the catalyst to the metering tank 8 through the feeding pipeline 4. The weighing sensor 9 can be a resistance strain gauge sensor, a piezoelectric sensor, or a capacitive sensor. The bottom surfaces of multiple weighing sensors 9 are flush with the upper surface of the lower head. Multiple weighing sensors 9 are used to monitor the weight of the catalyst added to the metering tank 8 and control the amount added in real time through the air valve control component. The fluidizing air inlet pipeline 13 is connected to the fluidizing air source. After opening the air inlet valve 14, gas can be introduced into the metering tank 8 to fluidize the catalyst. After fluidization, the catalyst is connected to the reactor 22 through the discharge pipeline 5.

[0035] In this embodiment, a feeding valve 3 and a shut-off valve 2 are sequentially installed on each feeding pipeline 4, with the shut-off valve 2 located upstream of the feeding valve 3; a discharge valve 6 is installed on each discharge pipeline 5, and an air inlet valve 14 is installed on each fluidizing air inlet pipeline 13. Each feeding valve 3, discharge valve 6, and air inlet valve 14 is electrically connected to the air valve control assembly.

[0036] In this embodiment, the air valve control component includes a controller 27, which is electrically connected to a solenoid valve group 28. The solenoid valve group 28 is connected to an instrument air supply line 30, and an instrument air valve 29 is installed on the instrument air supply line 30. The solenoid valve group 28 is electrically connected to each feeding valve 3, discharging valve 6, and air inlet valve 14.

[0037] The instrument air source is connected to the instrument air source pipeline 30, and the connection is controlled by the instrument air valve 29. Specifically, the instrument air source pipeline 30 is connected to the solenoid valve group 28. The controller 27 pneumatically controls the solenoid valve group. The multiple solenoid valves in the solenoid valve group 28 are respectively connected to the feeding valve 3, the discharging valve 6, and the air inlet valve 14. The controller 27 controls the opening or closing of the feeding valve 3, the discharging valve 6, and the air inlet valve 14 by controlling the solenoid valve group 28. The controller 27 is a PLC controller, which controls the feeding, discharging, and fluidization of the device separately, and has the effect of stable operation.

[0038] In this embodiment, the bottom plate of the metering barrel 8 is a gas distribution plate, and the gas distribution plate is a sintered metal wire mesh.

[0039] The gas distribution plate 11 facilitates the uniform distribution of the fluidizing gas source, accelerates the fluidization speed, and ensures more complete fluidization. The catalyst is fully fluidized in the metering tank 8 and then connected to the reactor 22 for reaction.

[0040] In this embodiment, the feeding pipeline 4 located in each cavity 10 is connected to the top of the corresponding metering tank 8; the discharging pipeline 5 located in each cavity 10 is connected to the bottom of the corresponding metering tank 8; the inner diameter of the feeding pipeline 4 is larger than the inner diameter of the discharging pipeline 5.

[0041] The discharge pipeline 5 is connected from the top to the bottom of the metering tank 8 to facilitate the complete discharge of the catalyst.

[0042] Example 2

[0043] A method for continuous or intermittent automatic and precise delivery of a catalyst includes the following steps:

[0044] S1: Open the instrument air valve 29 to connect the instrument air, and at the same time open multiple shut-off valves 2. The catalyst in multiple catalyst storage tanks 1 enters the feeding pipeline 4 before the feeding valve 3 by its own gravity. Connect the power supply of the controller 27, and the controller 27 starts to run, dividing the multiple chambers 10 into the first chamber and the second chamber.

[0045] S2: Catalyst is introduced into the metering barrel 8 in the first cavity. The controller 27 obtains the value of the weighing sensor 9 of each metering barrel 8 in the first cavity. After reaching the preset value, the introduction is stopped. Catalyst is introduced into the metering barrel 8 in the second cavity. The controller 27 obtains the value of the weighing sensor 9 of each metering barrel 8 in the second cavity. After reaching the preset value, the introduction is stopped and the equipment is ready for use.

[0046] S3: Fluidizing air is introduced into the first cavity to fluidize the catalyst in each metering tank 8 in the first cavity. After reaching the preset pressure value, the catalyst in the metering tank 8 in the first cavity is sent to the reactor 22 through the connected discharge pipeline 5. During the discharge process of the metering tank 8 in the first cavity, fluidizing air is introduced into the second cavity to fluidize the catalyst in each metering tank 8 in the second cavity. After reaching the preset pressure value, the fluidization is stopped and the catalyst is ready for use.

[0047] S4: Catalyst is introduced into the metering tank 8 in the first cavity. The controller 27 obtains the value of the weighing sensor 9 of each metering tank 8 in the first cavity. After reaching the preset value, the introduction is stopped. The catalyst in the metering tank 8 of the second cavity is sent to the reactor 22 through the connected discharge pipeline 5. During the discharge process of the metering tank 8 in the second cavity, fluidizing air is introduced into the first cavity to fluidize the catalyst in each metering tank 8 in the first cavity. After reaching the preset pressure value, the fluidization is stopped and the catalyst is ready for use.

[0048] S5: Catalyst is introduced into the metering tank 8 in the second cavity. The controller 27 acquires the value of the weighing sensor 9 of each metering tank 8 in the second cavity. After reaching the preset value, the introduction is stopped. The catalyst in the metering tank 8 in the first cavity is sent to the reactor 22 through the connected discharge pipeline 5. During the discharge process of the metering tank 8 in the first cavity, fluidizing air is introduced into the second cavity to fluidize the catalyst in each metering tank 8 in the second cavity. After reaching the preset pressure value, the fluidization is stopped and the catalyst is ready for use.

[0049] S6: Repeat operations S4 to S5.

[0050] In this embodiment, in S1, both the fluidizing air and the instrument air are nitrogen or inert gas.

[0051] In this embodiment, in S2, S4 and S5, the preset value of the weighing sensor 9 is 10 to 200 kg.

[0052] In this embodiment, in S3-S5, the pressure value of the fluidizing air for fluidization is 0.1 to 1.0 MPa greater than the back pressure value of the target reactor 22.

[0053] In this embodiment, in S2 to S5, the first partial cavity includes at least one cavity, and the second partial cavity includes at least one cavity.

[0054] Although the present invention has been disclosed above with reference to embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A continuous or intermittent automatic precision catalyst delivery device, comprising a fluidizing tank (7), characterized in that: The fluidizing tank (7) is fixed with a partition plate (12), which divides the fluidizing tank (7) into multiple chambers (10). Each chamber (10) is connected to a fluidizing air inlet pipe (13) at its bottom. Each chamber (10) is fixed with a metering tank (8), and each metering tank (8) is connected to a feeding pipe (4) at its top. Each metering tank (8) is connected to a catalyst storage tank (1) through the feeding pipe (4). Each metering tank (8) is connected to a discharge pipe (5). Multiple metering tanks (8) are connected to a reactor (22) through the discharge pipes (5). Multiple weighing sensors (9) are installed inside the fluidizing tank (7). Part of the multiple weighing sensors (9) is fixed on the inner wall of the fluidizing tank (7), and another part is fixed on the side wall of the partition plate (12). The multiple weighing sensors (9) are all located around the bottom wall of the metering barrel (8). The multiple weighing sensors (9) are all electrically connected to the air valve control component.

2. The catalyst continuous or intermittent automatic precision conveying device according to claim 1, characterized in that: Each feeding line (4) is equipped with a feeding valve (3) and a shut-off valve (2) in sequence, with the shut-off valve (2) located upstream of the feeding valve (3); each discharge line (5) is equipped with a discharge valve (6), and each fluidizing air inlet line (13) is equipped with an air inlet valve (14). Each feeding valve (3), discharge valve (6), and air inlet valve (14) is electrically connected to the air valve control assembly.

3. The catalyst continuous or intermittent automatic precision conveying device according to claim 1, characterized in that: The air valve control assembly includes a controller (27), which is electrically connected to a solenoid valve group (28). The solenoid valve group (28) is connected to an instrument air supply line (30), and an instrument air valve (29) is installed on the instrument air supply line (30). The solenoid valve group (28) is electrically connected to each feeding valve (3), discharging valve (6), and air inlet valve (14).

4. The catalyst continuous or intermittent automatic precision conveying device according to claim 1, characterized in that: The bottom plate of the metering barrel (8) is a gas distribution plate.

5. The catalyst continuous or intermittent automatic precision conveying device according to claim 1, characterized in that: The feeding line (4) located in each cavity (10) is connected to the top of the corresponding metering tank (8); the discharge line (5) located in each cavity (10) is connected to the bottom of the corresponding metering tank (8); the inner diameter of the feeding line (4) is larger than the inner diameter of the discharge line (5).

6. A method for continuous or intermittent automatic and precise delivery of catalyst using the apparatus as described in claims 1-5, characterized in that: The steps include the following: S1: Open the instrument air valve (29) to connect the instrument air, and at the same time open multiple shut-off valves (2). The catalyst in multiple catalyst storage tanks (1) enters the feeding pipeline (4) before the feeding valve (3) by its own gravity. Connect the power supply of the controller (27), and the controller (27) starts to run, dividing the multiple chambers (10) into the first chamber and the second chamber. S2: A catalyst is introduced into the metering barrel (8) in the first cavity. The controller (27) obtains the value of the weighing sensor (9) of each metering barrel (8) in the first cavity. After reaching the preset value, the introduction is stopped. A catalyst is introduced into the metering barrel (8) in the second cavity. The controller (27) obtains the value of the weighing sensor (9) of each metering barrel (8) in the second cavity. After reaching the preset value, the introduction is stopped and the catalyst is ready for use. S3: Fluidizing air is introduced into the first cavity to fluidize the catalyst in each metering tank (8) in the first cavity. After reaching the preset pressure value, the catalyst in the metering tank (8) of the first cavity is sent to the reactor (22) through the connected discharge pipeline (5). During the discharge process of the metering barrel (8) in the first cavity, fluidizing air is introduced into the second cavity to fluidize the catalyst in each metering barrel (8) in the second cavity. After reaching the preset pressure value, the fluidization is stopped and the catalyst is ready for use. S4: Catalyst is introduced into the metering tank (8) in the first cavity. The controller (27) obtains the value of the weighing sensor (9) of each metering tank (8) in the first cavity. After reaching the preset value, the introduction is stopped. The catalyst in the metering tank (8) of the second cavity is sent to the reactor (22) through the connected discharge pipeline (5). During the discharge process of the metering tank (8) in the second cavity, fluidizing air is introduced into the first cavity to fluidize the catalyst in each metering tank (8) in the first cavity. After reaching the preset pressure value, the fluidization is stopped and the catalyst is ready for use. S5: The catalyst is introduced into the metering tank (8) in the second cavity. The controller (27) obtains the value of the weighing sensor (9) of each metering tank (8) in the second cavity. After reaching the preset value, the introduction is stopped. The catalyst in the metering tank (8) of the first cavity is sent to the reactor (22) through the connected discharge pipeline (5). During the discharge process of the metering tank (8) in the first cavity, fluidizing air is introduced into the second cavity to fluidize the catalyst in each metering tank (8) in the second cavity. After reaching the preset pressure value, the fluidization is stopped and the catalyst is ready for use. S6: Repeat operations S4 to S5.

7. The method according to claim 6, characterized in that: In S1, both fluidizing air and instrument air use nitrogen or inert gas.

8. The method according to claim 6, characterized in that: In S2, S4 and S5, the preset value of the weighing sensor (9) is 10 to 200 kg.

9. The method according to claim 6, characterized in that: In S3 to S5, the pressure value of the fluidizing air for fluidization is 0.1 to 1.0 MPa greater than the back pressure value of the target reactor (22).

10. The method according to claim 6, characterized in that: In S2 to S5, the first part of the cavity includes at least one cavity, and the second part of the cavity includes at least one cavity.

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