阅读说明：本技术 一种聚丙烯材料的发泡设备及聚丙烯材料的发泡方法 (Foaming equipment and foaming method for polypropylene material ) 是由 李�一 常大山 崔婷 张建新 王婧 于 2019-10-23 设计创作，主要内容包括：本发明提供一种聚丙烯材料的发泡设备及聚丙烯材料的发泡方法,该设备包括：反应釜、与反应釜的上部相连的惰性发泡剂罐、与反应釜的下部相连的多个放料罐；多个放料罐对称布置,且其顶部分别设有压力平衡线,多条压力平衡线与反应釜的上部相连。该方法包括：将物料按配方加入反应釜,并向反应釜内通入惰性发泡剂；对反应釜内的物料进行加热,将反应釜内的物料稳定在发泡温度和发泡压力条件下；将与反应釜相连的多个放料罐同时开启,待反应釜内的物料转移完毕后,将各放料罐之间相互隔离开,并开启放料罐下部的放料阀,将物料迅速泄放入收集设备内。本发明能使发泡珠粒的发泡倍率均匀,降低了黏连珠粒等不合格产品率,提高了每批次生产的产量。(The invention provides a polypropylene material foaming device and a polypropylene material foaming method, wherein the device comprises: the device comprises a reaction kettle, an inert foaming agent tank connected with the upper part of the reaction kettle, and a plurality of discharging tanks connected with the lower part of the reaction kettle; a plurality of discharging buckets are symmetrically arranged, the tops of the discharging buckets are respectively provided with a pressure balance line, and the pressure balance lines are connected with the upper part of the reaction kettle. The method comprises the following steps: adding the materials into a reaction kettle according to a formula, and introducing an inert foaming agent into the reaction kettle; heating the materials in the reaction kettle, and stabilizing the materials in the reaction kettle under the conditions of foaming temperature and foaming pressure; a plurality of discharging tanks connected with the reaction kettle are opened simultaneously, after the materials in the reaction kettle are transferred, the discharging tanks are isolated from each other, and discharging valves at the lower parts of the discharging tanks are opened to discharge the materials into collecting equipment rapidly. The invention can ensure that the foaming multiplying power of the foaming beads is uniform, reduces the rate of unqualified products such as sticky beads and the like, and improves the yield of each batch of production.)

1. An apparatus for foaming a polypropylene material, comprising:

a reaction kettle;

the inert foaming agent tank is connected with the upper part of the reaction kettle;

the discharging tanks are connected with the lower part of the reaction kettle; the material placing tanks are symmetrically arranged, pressure balance lines are respectively arranged at the tops of the material placing tanks, and the pressure balance lines are connected with the upper part of the reaction kettle.

2. The polypropylene foaming apparatus according to claim 1, wherein a gas inlet and outlet is provided at the upper part of the reaction kettle, and the gas inlet and outlet is connected to the inert foaming agent tank; and the gas inlet and the gas outlet are also connected with an atmospheric vent pipe and a vent pipe.

3. The apparatus for foaming polypropylene according to claim 2, wherein a first automatic valve is provided on a line connecting to the atmospheric air vent; a first pressure regulating valve is arranged on a pipeline connected with the emptying pipe; and a second pressure regulating valve is arranged on a pipeline connected with the inert foaming agent tank, wherein the first pressure regulating valve and the second pressure regulating valve are controlled by a pressure controller arranged at the upper part of the reaction kettle.

4. The polypropylene foaming apparatus according to claim 1, wherein a discharge pipe is disposed at the bottom of the reaction kettle, the discharge pipe is connected to a feeding pipe on the discharge tank, and a second automatic valve is disposed on the feeding pipe.

5. The apparatus for foaming polypropylene according to claim 1, wherein a third automatic valve is disposed on the pressure balancing line.

6. The polypropylene foaming apparatus of claim 1, wherein the reaction kettle has a window.

7. A method for foaming a polypropylene material, comprising the steps of:

s1, adding the materials into a reaction kettle according to the formula, and introducing an inert foaming agent into the reaction kettle;

s2, heating the materials in the reaction kettle, and stabilizing the materials in the reaction kettle at foaming temperature and foaming pressure;

and S3, simultaneously opening a plurality of discharging tanks connected with the reaction kettle, after the materials in the reaction kettle are transferred, isolating the discharging tanks from each other, and opening discharging valves at the lower parts of the discharging tanks to rapidly discharge the materials into collecting equipment.

8. The method for foaming a polypropylene material according to claim 7, wherein the step S1 specifically comprises:

communicating the reaction kettle with the atmosphere;

communicating the plurality of discharge tanks with the gas phase space of the reaction kettle;

after the materials are added into the reaction kettle, isolating the reaction kettle from the atmosphere;

and introducing an inert foaming agent into the reaction kettle to replace residual air in the reaction kettle and the emptying tank.

9. The method for foaming a polypropylene material according to claim 7, wherein the step S2 specifically comprises:

heating the materials in the reaction kettle, and controlling the first pressure regulating valve and the second pressure regulating valve by a pressure controller arranged at the upper part of the reaction kettle to ensure that the kettle pressure reaches and is kept at the set foaming pressure; the first pressure regulating valve is used for discharging part of the inert foaming agent from the reaction kettle when the kettle pressure is higher, and the second pressure regulating valve is used for supplementing the inert foaming agent into the reaction kettle when the kettle pressure is lower.

Technical Field

The invention belongs to the field of processing of high polymer materials, and particularly relates to foaming equipment and a foaming method for a polypropylene material.

Background

Expanded polypropylene (EPP) beads are round-grained foamed materials obtained by foaming polypropylene fine particles having a diameter of 0.6 to 1.2mm, have excellent mechanical properties, heat resistance, low temperature resistance, chemical resistance, oil resistance and the like, and are widely used in the fields of packaging materials, automobile parts, thermal insulation, building materials and the like. The means for foaming the polypropylene particles can be classified into a batch kettle method, a continuous extrusion method, a mold pressing forming method, an injection molding method and the like according to the degree of continuity of operation, wherein the batch kettle method can ensure higher melt strength, is easy to realize high-magnification and high-closed-cell-ratio foaming, and is an important means for industrially producing EPP beads, and patents CN103665420A, CN103665567A, CN103665583A and the like all adopt the method for preparing the EPP beads, and the specific method is as follows: mixing polypropylene particles and an auxiliary agent in a reaction kettle, introducing an inert foaming agent (nitrogen or carbon dioxide) to increase the pressure of the kettle to foaming pressure, simultaneously raising the temperature to foaming temperature, continuously stirring for a period of time, and rapidly discharging the materials to a normal-temperature normal-pressure environment under the condition that the reaction kettle keeps basically constant pressure to complete foaming.

The kettle type method belongs to intermittent production, the yield of each batch is limited by the size of a reaction kettle, and if a small reaction kettle is used for producing in multiple batches, because errors exist in the operation process, the foaming multiplying power and the quality of EPP bead products in different batches are inevitably caused to be uneven, and the product quality is influenced; if use large-scale reation kettle production, then be subject to the size of blowing valve can't accomplish very big, it is longer to discharge the interior material of cauldron required time, need to mend pressure to reation kettle in the blowing simultaneously, it keeps cauldron internal pressure to keep invariable, otherwise blowing in-process cauldron internal pressure descends, the material that has not yet discharged just begins the inflation in reation kettle, light then arouses the product quality problem, it is heavy then arouse to glue between the pearl, block up the pipeline, and, large-scale reation kettle controls the pressure unstability easily when the blowing, even mend the pressure at the blowing simultaneously, inhomogeneous problem still appears easily in the product. Therefore, the production efficiency of the kettle-type method for producing EPP beads is difficult to improve, and the comprehensive cost is high, which is an important factor for limiting the wider application of the kettle-type method.

Disclosure of Invention

Features and advantages of the invention will be set forth in part in the description which follows, or may be obvious from the description, or may be learned by practice of the invention.

To overcome the problems of the prior art, the present invention provides a foaming apparatus for polypropylene material, comprising:

a reaction kettle;

the inert foaming agent tank is connected with the upper part of the reaction kettle;

the discharging tanks are connected with the lower part of the reaction kettle; the material placing tanks are symmetrically arranged, pressure balance lines are respectively arranged at the tops of the material placing tanks, and the pressure balance lines are connected with the upper part of the reaction kettle.

Optionally, a gas inlet and a gas outlet are formed in the upper part of the reaction kettle and connected with the inert foaming agent tank; and the gas inlet and the gas outlet are also connected with an atmospheric vent pipe and a vent pipe.

Optionally, a first automatic valve is arranged on a pipeline connected with the atmospheric vent pipe; a first pressure regulating valve is arranged on a pipeline connected with the emptying pipe; and a second pressure regulating valve is arranged on a pipeline connected with the inert foaming agent tank, wherein the first pressure regulating valve and the second pressure regulating valve are controlled by a pressure controller arranged at the upper part of the reaction kettle.

Optionally, a discharge pipeline is arranged at the bottom of the reaction kettle, the discharge pipeline is connected with a feeding pipeline on the discharging tank, and a second automatic valve is arranged on the feeding pipeline.

Optionally, the bottom of the discharging tank is provided with a discharging pipeline, and a discharging valve is arranged on the discharging pipeline.

Optionally, a third automatic valve is provided on the pressure balancing line.

Optionally, a window is arranged on the reaction kettle.

The invention provides a foaming method of a polypropylene material, which comprises the following steps:

s1, adding the materials into a reaction kettle according to the formula, and introducing an inert foaming agent into the reaction kettle;

s2, heating the materials in the reaction kettle, and stabilizing the materials in the reaction kettle at foaming temperature and foaming pressure;

s3, simultaneously opening the feeding pipelines of the plurality of discharging tanks connected with the reaction kettle, after the materials in the reaction kettle are transferred, isolating the discharging tanks from each other, and opening the discharging valves at the lower parts of the discharging tanks to rapidly discharge the materials into the collecting device.

Optionally, the step S1 specifically includes:

communicating the reaction kettle with the atmosphere;

communicating the plurality of discharge tanks with the gas phase space of the reaction kettle;

after the materials are added into the reaction kettle, isolating the reaction kettle from the atmosphere;

and introducing an inert foaming agent into the reaction kettle to replace residual air in the reaction kettle and the emptying tank.

Optionally, the step S2 specifically includes:

heating the materials in the reaction kettle, and controlling the first pressure regulating valve and the second pressure regulating valve by a pressure controller arranged at the upper part of the reaction kettle to ensure that the kettle pressure reaches and is kept at the set foaming pressure; the first pressure regulating valve is used for discharging part of the inert foaming agent from the reaction kettle when the kettle pressure is higher, and the second pressure regulating valve is used for supplementing the inert foaming agent into the reaction kettle when the kettle pressure is lower.

According to the foaming equipment and the foaming method for the polypropylene material, provided by the invention, the time required by discharging the materials in the kettle is reduced by utilizing the plurality of discharging tanks connected with the reaction kettle, and the pressure fluctuation in a short time in the discharging process can not cause great influence on products.

Drawings

Fig. 1 is a schematic structural diagram of a foaming apparatus for polypropylene material according to an embodiment of the present invention.

Fig. 2 is a schematic diagram of a symmetrical arrangement of the discharge tanks according to the embodiment of the present invention.

Detailed Description

The invention is described in further detail below with reference to the accompanying drawings:

as shown in FIG. 1, the present invention provides a polypropylene foaming apparatus, which comprises a reaction vessel 10, a discharge tank 20 and an inert foaming agent tank 30.

The volume of the reaction vessel is, for example, 3m³A feed inlet 11 and a gas phase inlet 13 are arranged at the upper part of the kettle, wherein the gas phase inlet 13 is connected with an atmospheric vent pipe 17, a vent pipe 19 and an inert foaming agent (nitrogen or carbon dioxide) tank 30, and a first automatic valve 12 is arranged on a pipeline connected with the atmospheric vent pipe 17; a first pressure regulating valve 14 is arranged on a pipeline connected with the emptying pipe 19; a second pressure regulating valve 16 is provided on a line connected to the inert foaming agent tank 30, wherein the first pressure regulating valve 14 and the second pressure regulating valve 16 are controlled by a pressure controller (PIC)18 provided in the upper portion of the reaction vessel 10. In addition, the upper end enclosure of the reaction kettle 10 is also provided with a sight glass 41, the kettle body is provided with an electric heater 43 controlled by a temperature controller (TIC)42, a stirrer 44 is arranged in the kettle, the bottom of the kettle is connected with a discharge pipeline 45 of DN500, no valve is arranged on the pipeline, and the discharge pipeline 45 is as short as possible on the premise of meeting the requirements of equipment arrangement, processing and the like.

In this embodiment, a plurality of discharge tanks 20, for example, 6 discharge tanks, are provided below the reaction kettle 10, as shown in fig. 2, the 6 tanks are symmetrically arranged to prevent bias flow between pipelines during feeding, and the volume of each tank is, for example, 500L. The upper part of the discharging tank 20 is provided with a feeding pipeline 21 of DN200, the feeding pipeline is connected with the discharging pipeline of the reaction kettle, and each feeding pipeline is provided with a second automatic valve 22. A discharging pipeline 23 of DN200 is arranged at the lower part of each discharging tank, and a discharging valve 24 is arranged on each discharging pipeline 23. The top of the discharging tank 20 is also provided with a pressure balance line 25, each balance line is provided with a third automatic valve 26, 6 balance lines are converged into a main pipe and then communicated with the inside of the reaction kettle 10, namely the discharging tank 20 is communicated with the gas phase space of the reaction kettle 10, so that the pressure in the discharging tank 20 is consistent with the pressure of the reaction kettle 10, and during specific implementation, the main pipe converged by the balance lines is connected with the upper end enclosure of the reaction kettle and can also be arranged at a position on the side surface of the reaction kettle barrel, which is higher (to avoid the feed liquid flowing into the pipe).

In the present invention, the number of the discharge tanks is mainly determined by the size of the reaction vessel, the size of the discharge tanks, and the available space, and it is considered that the size of the discharge tanks is 1m³Can achieve better effect within the range, and can be flexibly matched under the condition of space allowance and practical feasibility, such as 2m³The reaction kettle can be matched with 5 400L discharging tanks or 4 500L discharging tanks; or 5m³The reaction kettle can be matched with 6 800L discharging tanks. For reaction kettle 3m³Under the condition, the number of the discharge tanks is 4-10. The volume of the reaction vessel is not limited in the present invention.

The invention provides a foaming method of a polypropylene material, which can be implemented by adopting foaming equipment of the polypropylene material provided by the embodiment of the invention, and the foaming method specifically comprises the following steps:

s1, adding the materials into a reaction kettle according to the formula, and introducing an inert foaming agent into the reaction kettle;

before the production starts, the check valves are all in a closed state, taking the embodiment of the foaming equipment for polypropylene materials provided by the embodiment of the invention as an example, the first automatic valve 12 is firstly opened to communicate the reaction kettle 10 with the atmosphere, the third automatic valve 26 is opened to communicate the discharge tank 20 with the upper part of the reaction kettle 10, the materials are added into the reaction kettle through the feed inlet 11 according to the formula, and then the first automatic valve 12 is closed to isolate the reaction kettle from the atmosphere. The reaction kettle stirrer 44 is opened, the second pressure regulating valve 16 is opened, the inert foaming agent (nitrogen or carbon dioxide) is introduced into the reaction kettle 10 from the inert foaming agent tank 30 until the kettle pressure rises to a certain extent, the second pressure regulating valve 16 is closed, and the first pressure regulating valve 14 is opened to discharge residual air in the reaction kettle 10 and the emptying tank 20.

S2, heating the materials in the reaction kettle, and stabilizing the materials in the reaction kettle at foaming temperature and foaming pressure;

taking the embodiment of the foaming device of polypropylene material provided by the embodiment of the present invention as an example, the electric heating 43 is turned on to heat the material in the kettle, and the opening degree of the first regulating valve 14 and the second regulating valve 16 is changed to be automatically controlled by the pressure controller 18. In the embodiment, two use conditions are provided for the regulating valve, one is that the control of the pressure controller on the regulating valve is released in the instrument control system, the opening or closing of the regulating valve is controlled manually, and residual air is discharged; the other is to set the control value of the pressure of the reaction kettle, and the pressure controller 18 automatically controls the opening of the regulating valve in the reaction process to keep the kettle pressure at the set foaming pressure. The first pressure regulating valve 14 is used for discharging part of the inert foaming agent from the reaction kettle when the kettle pressure is higher, and the second pressure regulating valve 16 is used for supplementing the inert foaming agent into the reaction kettle when the kettle pressure is lower.

After the temperature and the pressure of the kettle reach the foaming temperature and the foaming pressure, the materials in the kettle are stabilized under the foaming temperature and the foaming pressure by the control of the temperature controller 42 and the pressure controller 18, and the materials are stirred continuously for a certain time to be prepared for discharging. It should be noted that the third automatic valve 26 is always in an open state during this process, so as to ensure that the pressure of the discharging tank is consistent with the pressure in the reaction vessel when the material enters the discharging tank 20 from the reaction vessel, otherwise, the change of the pressure will cause the particle type of the expanded beads to be inconsistent with the requirement.

And S3, simultaneously opening a plurality of discharging tanks connected with the reaction kettle, after the materials in the reaction kettle are transferred, isolating the discharging tanks from each other, and opening a discharging valve at the lower part of each discharging tank to rapidly discharge the materials into a collecting device.

Taking the embodiment of the foaming equipment for polypropylene materials provided by the embodiment of the invention as an example, the second automatic valve 22 at the upper part of the discharging tank 20 is opened simultaneously, the materials in the reaction kettle 10 rapidly flow into each discharging tank 20, after the materials in the reaction kettle 10 are completely transferred as observed from the sight glass 41, the reaction kettle stirrer 44, the electric heater 43, the first pressure regulating valve 14 and the second pressure regulating valve 16 are closed, the second automatic valve 22 and the third automatic valve 26 are closed, the discharging tanks are isolated from each other, the discharging valve 24 at the lower part of the discharging tank 20 is opened, and the materials are rapidly discharged into the collecting equipment, thereby completing the production.

According to the foaming equipment and the foaming method for the polypropylene material, provided by the invention, the time required for discharging the materials in the kettle is shortened by utilizing the plurality of discharging tanks connected with the reaction kettle, and short-time pressure fluctuation in the discharging process cannot cause great influence on products, so that the foaming multiplying power of the foaming beads is uniform, the unqualified product rate of sticky beads and the like is reduced, and the yield of each batch of production is improved.

The above-described embodiment is only one embodiment of the present invention, and it will be apparent to those skilled in the art that various modifications and variations can be easily made based on the application and principle of the present invention disclosed in the present application, and the present invention is not limited to the method described in the above-described embodiment of the present invention, so that the above-described embodiment is only preferred, and not restrictive.