JP3645486B2 - Stenter temperature control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a temperature control device for a stenter, and more particularly to a device for adjusting the temperature in a heating chamber of the stenter, that is, the heating temperature of a film to a desired temperature.
[0002]
[Prior art]
The stenter is a device for stretching a film heated to a predetermined temperature in a tunnel-shaped heating chamber in a uniaxial or biaxial direction, and the film is heated by blowing hot air adjusted to a predetermined temperature from the nozzle to the film. It is done by.
[0003]
FIG. 2 is an explanatory diagram showing an outline of a conventional stenter. This stenter partitions the heating chambers A, B, and C and the neutral zone N by the partition plate 11, and is formed on each of the upper and lower surfaces of the film F that is gripped by the clip chain and moves in the longitudinal direction in each heating chamber. A pair of upper and lower hot air blowing nozzles 12 for blowing hot air toward the hot air blowing nozzles 12 are provided, and a hot air supply device is provided to supply hot air of a predetermined temperature to each hot air blowing nozzle 12.
[0004]
The hot air supply device provided in each heating chamber draws hot air in the heating chamber from the suction port 13a of the suction passage 13, and supplies hot air to the hot air blowing nozzle 12 through the hot air supply passage 15 by the circulation fan 14. A path 16, a heater 17 provided in the suction path 13, a temperature controller 18 for controlling the heater 17 based on the temperature of the hot air flowing through the hot air supply path 15, and a part of the hot air in the heating chamber Is provided with an exhaust passage 20 for sucking the air by the exhaust fan 19 and discharging it to the outside, and an air supply passage 21 for introducing outdoor air upstream of the heater 17. Further, only the exhaust path 20 having the exhaust fan 19 is provided in the neutral zone N. Each path is provided with a damper 22 for adjusting the flow rate.
[0005]
The temperature of the hot air in each hot air supply device is set to a predetermined temperature by each heating chamber, and the hot air sucked into the suction path 13 is mixed with the air sucked from the air supply path 21 to circulate the fan 14. And is sent out from the circulation fan 14 to the hot air supply path 15 and supplied to the pair of upper and lower nozzles 12 at a predetermined flow rate. The temperature of the hot air to be supplied is performed by controlling the heater 17 so that the temperature detected by the temperature controller 18 becomes a predetermined temperature.
[0006]
[Problems to be solved by the invention]
However, in the conventional hot air supply apparatus, since the temperature controller 18 only adjusts the amount of heating in the heater 17, if the temperature detected by the temperature controller 18 is higher than the set temperature, control by the temperature controller 18 is performed. Cannot be performed. For example, when the hot air temperature in the heating chamber rises due to the heat generated by the circulation fan 14 or the intrusion of leaked air H from the adjacent chamber set to a high temperature, the amount of hot air exhausted from the heating chamber and the outdoor temperature into the heating chamber The amount of air introduced is adjusted, and outdoor air with a low temperature is introduced more than usual, and the temperature of the hot air circulating is lowered to control on the heating side.
[0007]
Although it is necessary to adjust the hot air exhaust amount and the outdoor air introduction amount so as to be the same as possible by the damper 22, it is actually difficult to balance both, and the hot air exhaust amount and the outdoor air introduction amount are A difference occurs between the two chambers, and the leakage into the adjacent chamber or the leakage from the adjacent chamber. These adjustments in one heating chamber also affect the temperature control of the adjacent chamber. Therefore, even if a heat insulating structure is adopted for the walls and partitions, it is difficult to control the temperature if a large temperature difference from the adjacent room is taken.
[0008]
For this reason, a neutral zone N is provided to make it less susceptible to the influence of the adjacent room. However, since a nozzle for blowing hot air is not usually installed in this part, the temperature is not good. And there will be unstable parts. Further, the entire stenter is increased in size, which is not preferable in terms of space and cost.
[0009]
The purpose of exhausting hot air from the heating chamber is to remove sublimation and volatile components from the film, and since the exhaust amount and introduction amount are set to be small compared to the hot air circulation rate, these are maximized. Even if it is set, the ability to lower the temperature of the circulating hot air is small, and the adjustable lower limit temperature naturally increases. Although it is possible to increase the amount of exhaust, etc., it is necessary to increase the size of ducts and fans in the air supply / exhaust route, and cooling with air with a small heat capacity reduces equipment costs, operating costs, etc. This is not a good idea.
[0010]
SUMMARY OF THE INVENTION An object of the present invention is to provide a temperature control device for a stenter that can cool hot air in a state where the supply / exhaust amount of the heating chamber is constant and can perform a wide temperature control.
[0011]
[Means for Solving the Problems]
In order to achieve the above object, a temperature control device for a stenter according to the present invention is a device that adjusts the temperature in a heating chamber of a stenter for stretching a thermoplastic resin film, and sucks hot air in the heating chamber and uses a circulation fan. Hot air circulation path for supplying hot air to the hot air blowing nozzle, a heater and a cooler provided in the hot air circulation path, a thermometer for measuring the temperature of the hot air supplied to the hot air blowing nozzle, and measurement of the thermometer A control unit for operating the heater or the cooler by comparing a temperature with a set temperature, an exhaust path for discharging a part of hot air in the heating chamber to the outside, and an air supply for introducing outdoor air into the hot air circulation path And a route.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a system diagram showing an embodiment of a temperature control device for a stenter according to the present invention, and shows one of a plurality of adjacent heating chambers. In addition, since the structure of the stenter itself can be formed in the same manner as in the prior art, its detailed description and illustration are omitted. Further, the same components as those of the conventional apparatus shown in FIG. 2 are denoted by the same reference numerals, and detailed description thereof is omitted.
[0013]
The temperature control device provided in the heating chamber A formed in the same manner as in the prior art includes a hot air blowing nozzle 12 similar to the conventional one, a suction passage 13 for sucking hot air in the heating chamber, a circulation fan 14 for circulating hot air, and hot air. A circulation path 16 having a hot air supply path 15 for supplying to the nozzle 12, an exhaust path 20 having an exhaust fan 19, an air supply path 21 for introducing outdoor air, and a damper 22 for adjusting the air volume of each path are provided. In addition, a cooling heat exchanger 31 and a heating heat exchanger 32 are provided in the suction path 13, a temperature detector 33 is provided in the hot air supply path 15, and detection of the temperature detector (thermometer) 33 is further performed. A temperature control device 34 is provided for adjusting the cooling amount and the heating amount in the cooling heat exchanger 31 and the heating heat exchanger 32 based on the temperature.
[0014]
The cooling heat exchanger 31 is provided with a refrigerant supply path for supplying a refrigerant such as low-temperature water or oil, and the heating heat exchanger 32 is supplied with a heat medium such as high-temperature steam or oil. A heating medium supply path for supplying is provided. The refrigerant supply path includes a refrigerant storage tank 35 that stores the refrigerant, a refrigerant pump 38 that sends the refrigerant to the cooling heat exchanger 31 through the refrigerant circulation path 37 having the valve 36, and heat exchange with the hot air using the cooling heat exchanger 31. And a refrigerant cooler 39 for cooling the refrigerant whose temperature has been raised by the cooling, and the refrigerant whose temperature has been lowered by the refrigerant cooler 39 is supplied to the cooling heat exchanger 31 via the refrigerant storage tank 35 or the refrigerant pump 38. It circulates to.
[0015]
The amount of cooling of the hot air in the cooling heat exchanger 31 is indirectly performed by adjusting the flow rate of the cooling water supplied to the refrigerant cooler 39 by opening and closing the control valve 40. That is, when the temperature detected by the temperature detector 33 is higher than a predetermined temperature, the cooling control valve 40 is opened by a signal from the temperature control device 34, and for example, the low-temperature cooling water in the cooling water tank 41 passes through the path 42 to cool the refrigerant. The refrigerant that is introduced into the condenser 39 and circulates through the refrigerant circulation path 37 is cooled to a predetermined temperature, and the refrigerant at a predetermined temperature cooled by the refrigerant cooler 39 is supplied to the cooling heat exchanger 31 by the refrigerant pump 38. This refrigerant and hot air sucked into the suction path 13 exchange heat, and the hot air is cooled to a predetermined temperature.
[0016]
When the temperature detected by the temperature detector 33 is lower than the predetermined temperature, the heating medium supply control valve 43 is opened by a signal from the temperature control device 34, and for example, hot steam from the boiler 44 is heated through the path 45. The steam is supplied to the heat exchanger 32 and the steam and the hot air sucked into the suction passage 13 exchange heat to heat the hot air.
[0017]
In this way, by exchanging hot air with the heat exchanger 31 for cooling or the heat exchanger 32 for heating, the hot air blown onto the film F according to the set temperature of each heating chamber can be easily and reliably set to a predetermined temperature. Since it can control, the extending | stretching operation of a film can be performed in the stable state. Further, by using a refrigerant or a heat medium having a large heat capacity, the set temperature can be changed quickly, and the change of the film can be dealt with in a short time, and the productivity can be improved.
[0018]
On the other hand, a part of the hot air in the heating chamber is exhausted from the exhaust fan 19 of the exhaust passage 20 by adjusting the air volume by the damper 22, and outdoor air corresponding to the exhaust amount is supplied from the air supply passage 21 to the cooling heat. It is introduced into the suction path 13 between the exchanger 31 and the heat exchanger 32 for heating. This supply / exhaust amount can be kept constant regardless of the temperature setting in the heating chamber, so that once it is set to an optimum state, almost no operation is required. In addition, since the minimum air supply / exhaust amount that can discharge sublimation and volatile components is sufficient, the duct and fan can be downsized.
[0019]
Furthermore, since the supply / exhaust amount is maintained in an optimum state, leakage to the adjacent heating chamber and leakage from the adjacent heating chamber hardly occur. Therefore, regardless of the temperature setting of the adjacent heating chamber, this heating chamber The temperature of A can be reliably maintained at a predetermined temperature. Further, since the conventional neutral zone is not required, the entire stenter can be reduced in size, and space and cost can be improved. Furthermore, the temperature can be set without worrying about the temperature difference between the adjacent heating chambers, and the temperature setting range can be widened. Therefore, the temperature setting of quality can be set, and the quality and stability of the product can be improved.
[0020]
The refrigerant supplied to the cooling heat exchanger 31 and the heat medium supplied to the heating heat exchanger 32 are arbitrary, and an appropriate one should be used according to the relationship with the heat exchange temperature and other equipment. Can do. Moreover, it can replace with the heat exchanger 32 for a heating, and can also employ | adopt the heating by a heater.
[0021]
【The invention's effect】
As described above, according to the present invention, it is possible to cool the hot air blown to the film, so the temperature of the hot air can be easily and reliably adjusted to a predetermined temperature, and the set temperature can be changed. Can also respond quickly. In addition, the supply / exhaust amount can be set to a minimum, and a neutral zone is not required, so that the stenter can be reduced in size and cost.
[Brief description of the drawings]
FIG. 1 is a system diagram showing an example of a temperature control device for a stenter according to the present invention.
FIG. 2 is an explanatory diagram showing an outline of a conventional stenter.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 12 ... Hot-air blowing nozzle, 13 ... Intake path, 14 ... Circulation fan, 15 ... Hot-air supply path, 16 ... Circulation path, 19 ... Exhaust fan, 20 ... Exhaust path, 21 ... Supply path, 22 ... Damper, 31 ... Cooling Heat exchanger, 32 ... Heat exchanger for heating, 33 ... Temperature detector, 34 ... Temperature controller, 35 ... Refrigerant storage tank, 37 ... Refrigerant circulation path, 38 ... Refrigerant pump, 39 ... Refrigerant cooler, 40 ... Cooling Control valve, 41 ... cooling water tank, 43 ... control valve for heating medium supply, 44 ... boiler, A ... heating chamber

Claims (1)

A device for adjusting the temperature in a heating chamber of a stenter for stretching a thermoplastic resin film, the hot air circulating path for sucking hot air in the heating chamber and supplying hot air to a hot air blowing nozzle by a circulation fan, and the hot air circulation path A heater and a cooler provided in the thermometer, a thermometer for measuring the temperature of the hot air supplied to the hot air blowing nozzle, and the heater or the cooler is operated by comparing the measured temperature and the set temperature of the thermometer A temperature control device for a stenter, comprising: a control unit that controls the exhaust air; an exhaust path that discharges a portion of hot air in the heating chamber; and an air supply path that introduces outdoor air into the hot air circulation path.

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