JPH07102623B2 - Volatile scatter remover - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a facility for producing plastic films such as polypropylene, polyester, nylon, etc., and in particular, a device for removing volatile scattered substances such as oligomers and oil mist, which is applied to a stretching device thereof. It is about.

(Prior Art) Conventionally, the most general method for producing a stretched film is to circulate hot air whose temperature is controlled to preheat, stretch, heat set and cool the film. However, this method has a drawback in that sublimates, oil mist and the like scatter in the hot air during operation and adhere to the film being manufactured. Examples of the scattered substances include oligomers during polyester stretching and additive evaporation components during polypropylene stretching.

By the way, in order to remove these scattered matters, conventionally, as shown in, for example, JP-A-58-65731, polyester oligomers are passed through the oxidation catalyst layer at a normal operating temperature without further heating the hot air. A method of burning off is disclosed. This method is characterized in that a noble metal such as platinum is supported on the oxidation catalyst layer and burned at a relatively low temperature of 200 to 250 ° C.

(Problems to be Solved by the Invention) However, even if the above-mentioned conventional method is applied to the stretching of a polypropylene film, a sufficient combustion effect cannot be obtained because the hot air temperature is usually as low as 160 ° C. In addition, the performance was rapidly deteriorated by the catalyst poison of oil mist generated from the additive, which was not practical.

On the other hand, for example, Japanese Unexamined Patent Publication No. 60-97829 discloses a method for removing oligomers and oil mist with an adsorbent such as activated carbon, alumina, and clay, and it is said that activated carbon pellets are particularly effective. However, general adsorbents such as activated carbon have so-called selectivity, which limits the substances that can be adsorbed, and have the characteristic that the adsorption capacity decreases as the adsorption temperature rises. For example, the stretching temperature of polyester film is
The temperature is 230 to 250 ° C., which is a temperature at which the adsorbed substance is usually desorbed from the activated carbon, and the adsorption operation of the oligomer at this temperature is extremely inefficient and requires a large amount of activated carbon. In addition, oil mists are generally difficult to adsorb and tend to break through early.

For the adsorbent that has reached the breakthrough, it is necessary to desorb the adsorbent by the desorption operation.
Since it has to be desorbed at a high temperature of 150 to 200 ° C, the adsorbent manufacturer generally entrusts the regeneration process.

The present invention provides a summary of the conventional problems such as the limitation of the hot air temperature range and the catalyst poison in the conventional oxidation catalyst, the selectivity of the adsorbent in the adsorbent, the reduction of the adsorption capacity in a high temperature atmosphere, and the short life. It is an object of the present invention to solve the above problems and to provide a volatile scattering material removing device for a plastic film stretching device, which is proposed in various film stretching processes and is capable of removing volatile scattering materials in hot air.

(Means for Solving the Problems) Therefore, the present invention provides a circulation path for hot air for heating a film, a closed high temperature field partitioned by a ceramic porous body, a heat exchanger, and the closed high temperature field for the circulation path. A part of the circulating hot air is introduced through the heat exchanger, and the inlet and outlet ducts circulate the hot air so as to return to the hot air circulation path through the heat exchanger again. Is a means for.

(Function) A part of the hot air that heats the film circulating in the hot air circulation path is introduced into the enclosed high temperature field partitioned by the ceramic porous body through the heat exchanger, and the hot air is again passed through the heat exchanger. Is returned to the circulation path, and the volatile scattered substances or components in the hot air can be completely burned and removed in the enclosed high temperature field.

(Embodiment) The embodiment of the present invention will be described in detail below with reference to the drawings.
The figure shows a principle diagram of a confined high temperature field 100 which is one of the main techniques of the present invention.

The basic configuration of the confined high temperature field 100 is composed of the ceramic porous bodies 101 and 101 'shown in FIG. 1B and the electric heater 102 in the space surrounded by the container 104. By introducing the air 103 containing a volatile scattered substance such as an oligomer to the enclosed high temperature field 100, the scattered substance can be efficiently burned and decomposed. Also the first
The graph of Fig. (A) shows the confined high temperature field 100 surrounded by the ceramic porous bodies 101 and 101 'and the temperature profile before and after it. The high temperature confinement effect depends on the presence or absence of the B ceramic porous body 101'. It shows that they are different.

Next, based on the principle shown in FIG. 1, an example in which a heat exchanger 105 is combined with a confined high temperature field 100 made of a ceramic porous body and connected to a stretched film manufacturing apparatus is shown in FIG. In FIG. 2, reference numeral 200 is a hot air circulating device part of the stretched film manufacturing apparatus, and 150 is a volatile scattered matter removing device including a closed high temperature field 100 and a heat exchanger 105.

The hot air circulating device (a part of the volatile scattered component removing device 150) unit 200 of the stretched film manufacturing apparatus includes a fan 201 for circulating the hot air 203 and a motor 20 for driving the fan 201.
2, a duct 204 which is a passage of the hot air 203, a nozzle box 205 for jetting the hot air 203 to blow it onto the film 206, a clip traveling mechanism 207 for pulling the film 206 left and right, and a hot air 203 for heating the hot air 203 It is composed of a heater 208 and the like.

On the other hand, the volatile scattered material removal device 150 is a part of the circulating hot air 203.
It is composed of an inlet duct 106 for receiving 3 and a heat exchanger 105, ceramic porous bodies 101 and 101 ', an electric heater 102, and an outlet duct 107 of a closed high temperature field 100 including a container 104.

Explaining the operation of the example configured as described above, volatile scattered substances such as oligomers volatilized and scattered from the film 206, after passing through the inlet duct 106 with the hot air 103,
Through the heat exchanger 105, the ceramic porous body 101, the electric heater 102, and the ceramic porous body 101 'are completely burned. Then, the combustion gas generated by this combustion is returned to the heat exchanger 10
5, the pre-combustion air 103 containing oligomers and the like is preheated, and at the same time, the combustion gas itself is cooled and the outlet duct 107
It is discharged to the vicinity of the heater 208 inside the hot air circulation device section 200 via the above. In the present embodiment, the electric heater 102 is used as the heat source of the high temperature field 100 for confinement, but the same effect can be obtained by introducing the fuel gas such as propane.

(Effects of the Invention) According to the present invention as described in detail above, since the volatile scattered substances in the hot air are burned and removed, the concentration of the volatile scattered substances in the hot air in the hot air circulation path can be significantly reduced, and Compared with the conventional method, it is possible to stably remove the volatile scattered substances in the circulating hot air, and it is possible to produce a high quality film with few defects at an extremely low cost.

[Brief description of drawings]

FIG. 1 (a) is a diagram for explaining the principle of the confined high temperature field in the embodiment of the present invention, FIG. 1 (b) is a structural diagram for explaining the principle of the confined high temperature field, and FIG. 2 is the same. FIG. 3 is a cross-sectional view of a volatile scattered material removing device including a hot air circulation device part of a stretched film manufacturing apparatus including a combination of a confined high temperature field and a heat exchanger. Description of the main parts of the figure 100 ... Closed high temperature field, 101, 101 '... Porous ceramic body 102 ... Electric heater, 103 ... Part of hot air 105 ... Heat exchanger, 106 ... Inlet duct 107 ... Outlet Duct, 150 …… Volatile scattered matter removing device 200 …… Hot air circulation device part, 201 …… Fan 202 …… Motor, 203 …… Hot air 204 …… Circulation path, 205 …… Nozzle box 206 …… Film, 208… …heater

Claims (1)

[Claims] 1. A circulation path of hot air for heating a film, a closed high temperature field partitioned by a ceramic porous body, a heat exchanger, and a part of the circulating hot air from the circulation path to the closed high temperature field. A volatile scattered matter removing device comprising: an inlet and an outlet duct for circulating hot air introduced through a heat exchanger and returned to the same hot air circulation path through the same heat exchanger.