JPS6197302A - Apparatus for removing volatile matter from polymer - Google Patents

Abstract

PURPOSE:To remove remaining volatile matter from polymer efficiently within a short time without detriment to the quality of the polymer, by heating it with a heating medium in a specified heat exchanger. CONSTITUTION:A polymer P such as a styrene polymer is fed to the polymer feed chamber 9 of a heat exchanger 3 through an entrance nozzle 10 of the body 1 of a devolatilizer and a pipe 11 and then fed to a crossflow plate-fin heat exchanger 6. A high-temperature heating medium H is supplied to the heat exchanger 6 from a feed pipe 7 and said polymer P is efficiently heated by controlling the temperature in the vessel by means of a temperature detector T, whereupon its viscosity is decreased in a specified range and at the same time the contained volatile matter is brought into a state of being easily discharged and then discharged from a discharge pipe 8. The polymer P decreased in viscosity is injected as a polymer stream P into the body 1 kept in a state of a diminished pressure, and the evaporated volatile matter B is discharged from an exit 20, while the polymer stream in the form of a thin sheet is allowed to fall along the inside wall of the body 1 and is discharged from an exit 19.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention provides an apparatus for efficiently removing volatile substances such as solvents and nitrates contained in polymers such as styrene polymers in a short time. It is related to.

[Prior art]

Polymers such as styrene polymers sent out from the polymerization process are rarely completely reacted, and the polymers usually contain volatile substances such as unreacted sulfur and solvents. ing. Since these volatile substances reduce or deteriorate the quality of the polymer and further deteriorate the quality of products obtained from this polymer, they must be removed as soon as possible. Therefore, in order to improve the quality of the polymer, the polymer transferred from the polymerization process is treated with a volatile substance removal device.

This device for removing volatile substances is a device (Japanese Patent Publication No. 48-297
No. 97, Japanese Unexamined Patent Publication No. 51434781) are known.

However, these devices ■ It is necessary to foam the polymer.

■ The removal efficiency of volatile substances is not sufficient.

■ The device as a whole had drawbacks such as being large and complicated.

[Purpose of the invention]

The present invention eliminates the drawbacks of the conventional devices for removing volatile substances from polymers such as styrene-based polymers. The object of the present invention is to provide a device for removing sexual substances.

[Summary of the invention]

To achieve the above object, the present invention has a structure in which a plate-fin type heat exchanger is provided in a main body capable of depressurization, and this heat exchanger has a pipe line through which a heat medium is supplied and discharged, and a polymer. A supply pipe is provided separately, and the polymer is supplied from the pipe to a heat exchanger, heated, and further discharged into the main body from one of the heat exchangers. This is a characteristic feature.

There are no restrictions on the polymers that can be applied to the apparatus of the present invention, but examples include single ffi polymerizations or copolymers of styrene monomers such as styrene, vinyltoluene, and α-methylstyrene, styrene monomers and acrylonitrile, Particularly suitable are styrenic polymers such as copolymers with monomers such as methyl acrylate and methyl methacrylate, and rubbery tonocopolymers copolymerizable with styrene monomers.

〔Example〕

Next, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a side cross-sectional view showing an outline of a device for removing volatile substances in a styrenic polymer according to an embodiment of the present invention, in which a heat exchange device 3 is provided in a main body l having a jacket 2. . The heat exchange device 3 can also be provided outside the main body 1. A heat medium is supplied to the jacket 2 from a supply port 4 provided at the bottom thereof, and is discharged from a discharge port 5 to heat the wall surface of the main body 1.

As the heat exchange device 3 in the present invention, a plate-fin type heat exchanger 6 is particularly used.

The fin types of plate fin type heat exchangers are ■
Plain type (flat plate fin), ■Louver type, ■Serrate type (flange fin), ■Perforate type (perforated fin),
(2) Various types can be used, such as a helibone type (wavy fin), but a serrate type is particularly preferred.

The flow system may be a cross-flow type, a counter-flow type, a parallel-flow type, or a combination thereof, but the cross-flow type is particularly preferred from the structural point of view.

Note that there is another type of heat exchange device, such as a shell-and-tube heat exchanger, but it is not preferred because its heating efficiency is poor and the device is large.

Here, a cross-flow plate heat exchanger will be explained as an example.

This heat exchanger 6 is provided with a horizontal passage through which the heat medium () 1 passes and a vertical passage through which the polymer P passes. Discharge.

The polymer P is supplied to the polymer supply chamber 9 provided at the upper part of the heat exchanger 6 via an inlet nozzle 10 and piping 11, and is dispersed and passed through the vertical passage of the heat exchanger 6. After being heated, it is configured to be discharged as a polymer stream p into the body 1 under reduced pressure. Note that the member indicated by the symbol T is a temperature sensing end.

As shown in FIGS. 2 to 6, the heat exchange device 3 includes heat medium chambers 15 provided on both sides of a horizontal passage of a plate-fin type heat exchanger 6, and a supply pipe 7 and a discharge pipe 8, respectively.
are connected. A polymer supply chamber 9 is provided in the upper part on the vertical passage side, and a pipe 11 for supplying the polymer P is connected thereto. .

As shown in FIGS. 5 and 6, the plate fin type heat exchanger 6 has metal plates (fins) 16A and 17A each having an uneven or corrugated cross section that are orthogonal to each other via a partition plate 18. It is a structure in which metal plates (fins) 16A form a large number of vertical passages 16, and metal plates (fins) 17A form a large number of horizontal roads 17.

Therefore, the vertical and horizontal passages are opened in the shape of a honeycomb. For example, when looking at the vertical passage 16, the polymer flows in the heat exchanger 6 in the form of many strings, and at the exit of the vertical passage 16, the polymer flows in the form of a sheet. Otherwise, it will be discharged in the form of a thick string.

Further, since the horizontal passages 17 for the heat medium H separated by the partition plates 18 are arranged adjacent to both sides of the vertical passage 16 through which the polymer P passes, the exchange of heat is extremely good.

The polymer P is supplied into the polymer supply chamber 9 of the heat exchanger 3 via the inlet nozzle lO1 piping 11, and while passing through the vertical passage 16, the polymer P passes through the horizontal passage 1'? After being heated to a predetermined temperature by the high-temperature heat medium H inside, it is discharged from the open end of the vertical passage 16 opened at the bottom of the heat exchange device 3 into the main body 1 maintained in a reduced pressure state.

In this case, while the polymer P passes through the vertical passage 16, it is efficiently heated by the heat medium H flowing in the adjacent horizontal passage 17, and its viscosity is reduced to a predetermined range. The volatile substances contained in the gas are easily discharged.

When the polymer P whose viscosity has been reduced as described above is discharged as a polymer stream P into the main body 1 maintained in a reduced pressure state,
Volatile substances instantaneously evaporate (or flash) from inside the body, so the polymer stream p descends through the main body l in the form of a thin sheet or string, and then exits from the discharge port 19 provided at the bottom of the main body l. be discharged. Further, the volatile substance B evaporated from the polymer stream P is discharged from the discharge port 20 and treated as necessary.

〔Effect of the invention〕

In the present invention, the heat exchange device 3 is constructed using a plate-fin type heat exchanger 6, and the heating medium H is supplied to one passage and the polymer P is supplied to the other passage. The present invention is characterized in that the polymer P is discharged into the main body 1 maintained in a reduced pressure state as a polymer stream P in a sheet-like or string-like separated state.

Therefore, according to the present invention, the following effects can be achieved.

(Since the heat exchange device 3 is configured using the 11-plate fin type heat exchanger 6, the polymer P is heated directly by the heat medium 11, and the heating efficiency is extremely good.

Therefore, the polymer P can be heated in a short time, and the volatile substances B contained in the polymer P can be effectively evaporated or flashed and removed in the main body 1 maintained under reduced pressure. can do.

(2) Since the plate-fin type heat exchanger 6 has a high heat transfer rate despite being small and lightweight, a large amount of the polymer P can be heat-treated. This makes it possible to downsize the heat exchange device 3 and downsize the entire volatile substance B removal device.

(3) According to the apparatus according to the present invention, since the polymer P can be processed in a short time, the degree of polymerization of the polymer P is not changed or deteriorated, and therefore,
The quality of products obtained from this polymer can be improved.

In the embodiment of the apparatus according to the present invention, the heated polymer P is directly discharged from the passage of the plate-fin type heat exchanger 6 into the main body l which is in a reduced pressure state. An orifice plate is provided at the opening end of the orifice plate, and the cross-sectional shape of the polymer P discharged thereby is set to be round, foot-shaped, Y-shaped, or X-shaped, and the size of the hole or notch in this orifice plate is adjusted. By doing so, it is possible to form a discharge port suitable for the polymer and create conditions where the most volatile substances can easily evaporate, thereby shortening the distance that the polymer stream p flows, and as a result, the device can be made smaller. In some cases you can.

[Brief explanation of the drawing]

FIG. 1 is a front sectional view schematically showing an apparatus for removing volatile substances from a polymer according to an embodiment of the present invention, FIG. 2 is a side view showing a heating device, FIG. 3 is a plan view of the same, and FIG. Figure 4 is a bottom view of the same, Figure 5 is an enlarged view of section A in Figure 4, and Figure 6 is a view of Y- in Figure 5.
It is a sectional view taken along the Y arrow. DESCRIPTION OF SYMBOLS 1... Main body, 2... Jacket, 3... Heat exchange device, 4... Supply port, 5... Discharge port, 6... Heat exchanger, 7... Supply pipe, 8 ... Discharge pipe, 10 ... Inlet nozzle, 11 ... Piping, 15 ... Heat medium chamber, 16.
...Vertical passage, 17...Horizontal passage. Figure 1 Figure 2 p

Claims (1)

[Claims] A plate fin type heat exchanger is installed in the main body that can reduce pressure.
This heat exchanger is provided with a separate pipe line for supplying and discharging the heat medium and a pipe line for supplying the polymer, and the polymer is supplied from the pipe line to the heat exchanger and heated. . A device for removing volatile substances from a polymer, further comprising a device configured to discharge volatile substances from one of the heat exchangers into the main body.