Feeding device for polypropylene powder dryer

Abstract

The utility model belongs to the technical field of chemical production devices, and particularly relates to a feeding device for a polypropylene powder dryer, a first feeding hole is formed in the top of the polypropylene powder dryer, and the feeding device is arranged above the polypropylene powder dryer; the feeding device comprises a barrel, and a second feeding hole is formed in the top of the barrel; one end of the conical discharging distributor is connected with the inner wall of the cylinder body, and the other end of the conical discharging distributor is connected with the first feeding port; the two annular steam distributors are different in diameter, and a plurality of openings are formed in the tops and the annular inner side walls of the annular steam distributors at intervals in a staggered mode. According to the device, polypropylene powder and steam jetted by the steam distributor can form countercurrent, so that full contact is realized, the contact area of the polypropylene powder and the steam is increased, the contact time of the polypropylene powder and the steam is prolonged, and better catalyst removal and dealkylation effects are achieved.

Description

Technical Field

[0001] The utility model belongs to the technical field of chemical production devices, and in particular relates to a feeding device for a polypropylene powder dryer. Background Art

[0002] At present, homopolymer polypropylene powder is usually prepared by the domestic SPG process, that is, the "slurry polymerization + horizontal kettle gas phase polymerization" process. After the polypropylene powder is prepared, the powder needs to be dried.

[0003] The disc dryer is a type of existing polypropylene powder dryer, which further devolatilizes the polypropylene powder by adding steam, and reduces the partial pressure of gaseous propylene at the same time, thereby reducing the content of hydrocarbons entrained in the polypropylene powder, recovering hydrocarbons as much as possible, reducing the content of hydrocarbons entrained in the powder entering the displacement kettle, and preventing the residual catalyst from degrading the polypropylene powder by reacting with the residual catalyst in the polypropylene powder. The steam entry points of the existing disc dryer are mainly the material legs, the end of the cylinder and the feed port. However, the steam entry design of the existing disc dryer at the feed port is to spray steam directly from the steam interface to the lower outside of the feed port powder distributor. The steam cannot directly contact the polypropylene powder, resulting in almost zero deactivation effect of the dryer inlet, resulting in poor hydrocarbon recovery effect of the disc dryer. Utility Model Content

[0004] The utility model aims to solve the problem of poor contact between steam and polypropylene powder at the feed inlet of the dryer described in the above-mentioned background technology. A new feeding device for a polypropylene powder dryer is proposed. The device allows the steam at the feed inlet to fully contact with the polypropylene powder, thereby reducing the hydrocarbon content entrained in the polypropylene powder, thereby improving the hydrocarbon recovery rate.

[0005] The technical solution adopted to achieve the above purpose is a feeding device for a polypropylene powder dryer, wherein a first feeding port is provided at the top of the polypropylene powder dryer, and the feeding device is arranged above the polypropylene powder dryer; the feeding device comprises:

[0006] A cylinder, wherein a second feed inlet is provided at the top of the cylinder;

[0007] A conical material distributor, one end of which is connected to the inner wall of the cylinder, and the other end of which is connected to the first feed port;

[0008] A first steam distributor, the first steam distributor comprising a first connecting pipe and a first annular pipe, the first connecting pipe is connected to the first annular pipe, a top pipe wall of the first annular pipe is provided with a plurality of first openings, an inner pipe wall of the first annular pipe is provided with a plurality of second openings, and the first openings and the second openings are arranged alternately;

[0009] The second steam distributor comprises a second connecting pipe and a second annular pipe, the second connecting pipe is connected to the second annular pipe, a top pipe wall of the second annular pipe is provided with a plurality of third openings, an inner pipe wall of the second annular pipe is provided with a plurality of fourth openings, and the third openings and the fourth openings are arranged alternately.

[0010] In the above technical solution, the first opening and the third opening provide vertical steam guidance, and the second opening and the fourth opening provide horizontal steam guidance. When the polypropylene powder is added from the second feed port, the polypropylene powder forms a countercurrent with the steam of each opening, thereby enhancing the contact effect between the polypropylene powder and the steam, allowing the steam to fully react with the residual catalyst, avoiding the decomposition of the polypropylene powder under the influence of the catalyst, improving the stability of the polypropylene product, and allowing the hydrocarbon substances attached to the polypropylene powder to be fully evaporated and replaced, thereby achieving a better hydrocarbon recovery effect.

[0011] Furthermore, the feeding device also includes a plurality of steam nozzles, and the plurality of steam nozzles are fixedly connected to the first opening, the second opening, the third opening and the fourth opening respectively.

[0012] Furthermore, the diameter of one end of the conical material distributor connected to the first feed port is smaller than that of one end of the conical material distributor connected to the inner wall of the cylinder.

[0013] Furthermore, the first annular tube and the second annular tube are located inside the conical material distributor.

[0014] Furthermore, the diameter of the first annular tube is greater than the diameter of the second annular tube.

[0015] Furthermore, the diameter of the second annular tube is greater than the diameter of the first feed port.

[0016] In the above technical solution, the design prevents the second annular tube or the first annular tube from falling off during use and falling into the dryer to cause stirring jam and other accidents.

[0017] Furthermore, the feeding device also includes a first steam pipeline and a second steam pipeline, the first connecting pipe passes through the conical feeding distributor and the cylinder and is connected to the first steam pipeline, and the second connecting pipe passes through the conical feeding distributor and the cylinder and is connected to the second steam pipeline.

[0018] In the above technical solution, the steam source is provided to the steam distributor through an external steam pipeline, and a rotor flow meter, a pressure gauge and a manual valve can be arranged on the steam pipeline to monitor, adjust and switch the steam in real time.

[0019] Further, the inner diameter of the first annular tube is 700-900 mm, the inner diameter of the second annular tube is 500-600 mm, the diameter of the first feed port is 500 mm, and as a preferred solution, the inner diameter of the first annular tube is 800 mm, and the inner diameter of the second annular tube is 500 mm.

[0020] Further, the diameters of the first opening, the second opening, the third opening and the fourth opening are 8-10 mm. As a preferred solution, the diameters of the first opening, the second opening, the third opening and the fourth opening are 8 mm.

[0021] Furthermore, the first annular tube is provided with 10-14 first openings and 10-14 second openings, and the second annular tube is provided with 6-10 third openings and 6-10 fourth openings. As a preferred embodiment, the first annular tube is provided with 12 first openings and 12 second openings, and the second annular tube is provided with 8 third openings and 8 fourth openings.

[0022] The advantages of the utility model are:

[0023] 1. The utility model sets two steam distributors with different diameters so that the polypropylene powder and the steam sprayed by the steam distributor form a countercurrent, thereby fully contacting each other, thereby increasing the contact area and contact time between the polypropylene powder and the steam, and achieving better catalyst removal and hydrocarbon removal effects.

[0024] 2. The utility model can reduce the content of hydrocarbon gas in the tail gas of the polypropylene powder dryer, wherein the average propylene content can be reduced from 1.20791% to 0.47595%, and the propane content can be reduced from 0.52504% to 0.23595%. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0026] Figure 1 It is a structural schematic diagram of the utility model;

[0027] Figure 2 This is a schematic diagram of the structure of the first steam distributor of the utility model;

[0028] Figure 3 It is a structural schematic diagram of the second steam distributor of the utility model.

[0029] Illustrations: 1. Cylinder, 2. Conical feed distributor, 3. First steam distributor, 4. Second steam distributor, 5. First feed port, 6. Steam nozzle, 7. First steam pipeline, 8. Second steam pipeline, 101. Second feed port, 301. First connecting pipe, 302. First annular pipe, 303. First opening, 304. Second opening, 401. Second connecting pipe, 402. Second annular pipe, 403. Third opening, 404. Fourth opening. DETAILED DESCRIPTION

[0030] In order to enable those skilled in the art to better understand the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only embodiments of a part of the present invention rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the protection scope of the present invention.

[0031] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0032] like Figure 1 As shown, a feeding device for a polypropylene powder dryer is arranged above the polypropylene powder dryer, and a first feeding port 5 is provided on the top of the polypropylene powder dryer. The feeding device consists of a cylinder 1, a conical feed distributor 2, a first steam distributor 3, a second steam distributor 4, a steam nozzle 6, a first steam pipeline 7 and a second steam pipeline 8, wherein a second feeding port 101 is provided on the top of the cylinder, an end of the conical feed distributor with a smaller diameter is connected to the first feeding port, and an end of the conical feed distributor with a larger diameter is connected to the inner wall of the cylinder.

[0033] like Figure 2 As shown, the first steam distributor consists of a first connecting pipe 301 and a first annular pipe 302. The inner diameter of the first annular pipe is 800 mm. The first connecting pipe is connected to the first annular pipe. The top pipe wall of the first annular pipe is provided with 12 first openings 303 with a diameter of 8 mm, and the inner pipe wall of the first annular pipe is provided with 12 second openings 304 with a diameter of 8 mm.

[0034] like Figure 3 The second steam distributor is composed of a second connecting pipe 401 and a second annular pipe 402. The inner diameter of the second annular pipe is 500 mm. The second connecting pipe is connected to the second annular pipe. The top pipe wall of the first annular pipe is provided with 8 third openings 403 with a diameter of 8 mm. The inner pipe wall of the second annular pipe is provided with 8 fourth openings 404 with a diameter of 8 mm.

[0035] A steam nozzle 6 is welded at each of the first opening, the second opening, the third opening and the fourth opening.

[0036] In this embodiment, the first annular tube and the second annular tube are located inside the conical material distributor, the first annular tube is located above the second annular tube, the first connecting tube passes through the conical material distributor and the cylinder and is connected to the first steam pipeline, and the second connecting tube passes through the conical material distributor and the cylinder and is connected to the second steam pipeline.

[0037] The working principle and process of the utility model are as follows: the steam flow rate is adjusted according to the output of the polypropylene powder, 1.0MPa steam is passed from the first steam pipeline into the first connecting pipe and into the first annular pipe, and 1.0MPa steam is passed from the second steam pipeline into the second connecting pipe and into the second annular pipe. In the present embodiment, the steam flow rate is controlled to be 80kg / h, and the steam is sprayed upward and toward the inner side of the annular pipe respectively through the steam nozzle. The polypropylene powder is poured into the cylinder from the second feed port, and enters the dryer from the first feed port under the action of its own gravity and pressure difference. Before entering the dryer, the polypropylene powder forms a countercurrent with the steam sprayed upward and toward the inner side, so that the agglomerated powder is dispersed and fully contacted with the steam, and due to the effect of the steam spraying upward, the polypropylene powder prolongs the time in the feeding device, so that the catalyst entrained by the polypropylene powder fully reacts with the steam, and the entrained hydrocarbon substances are fully evaporated and replaced, and fully recovered.

[0038] Application Example 1:

[0039] The feeding device described in the embodiment was installed on a disc dryer to carry out continuous polypropylene powder drying. The contents of nitrogen, propylene and propane gases in the tail gas generated by the disc dryer were detected. The detection results are shown in Table 1.

[0040] Table 1 Tail gas content of application example 1

[0041] Sampling time and items Nitrogen mol% Propylene mol% Propane mol% 2024 / 1 / 20 9:00 99.84241 0.10182 0.05244 2024 / 1 / 19 15:00 99.33544 0.43552 0.22082 2024 / 1 / 17 14:10 99.06583 0.59543 0.32847 2024 / 1 / 16 14:31 99.52976 0.29454 0.16486 2024 / 1 / 15 14:00 99.31963 0.39862 0.22144 2024 / 1 / 15 8:25 99.20057 0.55197 0.23798 2023 / 12 / 27 8:00 99.15071 0.55126 0.26494 2023 / 12 / 25 15:35 99.05557 0.60464 0.32364 2023 / 12 / 22 8:30 99.04276 0.63970 0.2834 2023 / 12 / 20 8:00 99.13638 0.58604 0.26147 Maximum 99.87241 0.63970 0.32847 Minimum 99.04276 0.10182 0.05244 average value 99.26791 0.47595 0.23595

[0042] Comparative Example 1:

[0043] A disc dryer without the feeding device described in the embodiment was used to continuously dry polypropylene powder. The contents of nitrogen, propylene and propane gases in the tail gas generated by the disc dryer were detected. The detection results are shown in Table 2.

[0044] Table 2 Tail gas content of comparative example 1

[0045]

[0046]

[0047] The same amount of steam was introduced in the above Application Example 1 and Comparative Example 1.

[0048] From the comparison of Table 1 and Table 2, it can be seen that the average nitrogen content in the tail gas increased from 98.22774% to 99.26791%, the average propylene content decreased from 1.20791% to 0.47595%, and the average propane content decreased from 0.52504% to 0.23595%, indicating that the recovery rate of hydrocarbon gases such as propylene and propane in the disc dryer can be significantly improved after the use of the annular steam distributor.

[0049] Finally, it should be noted that this embodiment is only used to illustrate the present invention and does not limit the scope of the present invention. In addition, it should be understood that after reading the content of the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the claims attached to this application.

Claims

1. A feeding device for a polypropylene powder dryer, characterized in that: The top of the polypropylene powder dryer is provided with a first feed port (5), and the feeding device is arranged above the polypropylene powder dryer; the feeding device comprises: A cylinder (1), wherein a second feed inlet (101) is provided at the top of the cylinder; A conical material distributor (2), one end of which is connected to the inner wall of the cylinder, and the other end of which is connected to the first feed port; A first steam distributor (3), the first steam distributor comprising a first connecting pipe (301) and a first annular pipe (302), the first connecting pipe being in communication with the first annular pipe, a top pipe wall of the first annular pipe being provided with a plurality of first openings (303), an inner pipe wall of the first annular pipe being provided with a plurality of second openings (304), the first openings and the second openings being arranged alternately and spaced apart; A second steam distributor (4), the second steam distributor comprises a second connecting pipe (401) and a second annular pipe (402), the second connecting pipe is connected to the second annular pipe, a top pipe wall of the second annular pipe is provided with a plurality of third openings (403), an inner pipe wall of the second annular pipe is provided with a plurality of fourth openings (404), and the third openings and the fourth openings are arranged in a staggered manner.

2. The feeding device according to claim 1, characterized in that: The feeding device further comprises a plurality of steam nozzles (6), wherein the plurality of steam nozzles are fixedly connected to the first opening, the second opening, the third opening and the fourth opening respectively.

3. The feeding device according to claim 1, characterized in that: The diameter of one end of the conical material distributor connected to the first feed port is smaller than that of one end of the conical material distributor connected to the inner wall of the cylinder.

4. The feeding device according to claim 1, characterized in that: The first annular pipe and the second annular pipe are located inside the conical material distributor.

5. The feeding device according to claim 1, characterized in that: The diameter of the first annular tube is greater than the diameter of the second annular tube.

6. The feeding device according to claim 1, characterized in that: The diameter of the second annular tube is greater than the diameter of the first feed opening.

7. The feeding device according to claim 1, characterized in that: The feeding device also includes a first steam pipeline (7) and a second steam pipeline (8), wherein the first connecting pipe passes through the conical feeding distributor and the cylinder and is connected to the first steam pipeline, and the second connecting pipe passes through the conical feeding distributor and the cylinder and is connected to the second steam pipeline.

8. The feeding device according to claim 1, characterized in that: The inner diameter of the first annular tube is 700-900 mm, the inner diameter of the second annular tube is 500-600 mm, and the diameter of the first feed port is 500 mm.

9. The feeding device according to claim 1, characterized in that: The diameters of the first opening, the second opening, the third opening and the fourth opening are 8-10 mm.

10. The feeding device according to claim 1, characterized in that: The first annular tube is provided with 10-14 first openings and 10-14 second openings, and the second annular tube is provided with 6-10 third openings and 6-10 fourth openings.

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