JPS607192B2 - Hot air drying method for sizing yarn - Google Patents

Description

[Detailed description of the invention] The present invention relates to a hot air drying method for sized yarn.

In conventional hot air dryers for sized yarn, the amount of thermal energy supplied into the drying chamber is kept constant and the yarn is dried under the same conditions. A temperature sensing element such as a thermocouple is provided near the center of the drying chamber.

The hot air delivery heater is configured to be automatically controlled so that the temperature of the portion where the temperature sensing element is provided is maintained at a predetermined constant value. In hot air dryers, there is often a temperature gradient that decreases from the airflow outlet toward the suction port, and such temperature gradient changes with yarn speed.

Such a temperature gradient and its changes naturally affect the degree of dryness of the sized yarn. However, with the above-mentioned control system, the temperature is sensed near the air outlet or the center of the drying chamber, so the effects of such temperature gradients and changes may not be detected at all. Even if it were possible, it would be incomplete. In other words, although conventional control methods have the function of keeping the hot air temperature constant near the location where the temperature sensor is installed, it is necessary to consider the temperature gradient and the effect of its changes on the sizing yarn drying chamber. It does not have the function of changing the heat energy supplied into the drying chamber depending on the temperature. In addition, when determining the hot air temperature in the area where the temperature sensor is installed, it is necessary to set the temperature so that the thread does not have an adverse effect even when the thread is stopped or running at low speed. . For this reason, there is a tendency for the set temperature to be set low, which has the drawback of low yarn drying efficiency. Therefore, it is necessary to increase the drying efficiency, so measures such as making the drying chamber longer and increasing the speed of hot air are being taken. However, with such a device, unreasonable tension is applied to the yarns during drying, and the yarns may dry in a state in which they are in contact with each other.

Therefore, when this is forcibly torn, accidents such as thread breakage and fuzzing may occur. The object of the present invention is to provide a sized yarn that supplies an appropriate amount of energy into the drying chamber according to the amount of yarn passing through the drying chamber and the running speed, and also eliminates the drawbacks of the conventional hot air dryer as described above. The purpose of this invention is to provide a hot air drying method.

The present invention attempts to achieve the above object by maintaining the temperature of the hot air at a predetermined set value after it has been used to dry the sized yarn.

More specifically, a temperature sensor such as a thermocouple is installed near the air suction port to sense the temperature of the hot air after it is used to dry the yarn, and the heater controller receives the output from this temperature sensor. The heater is configured to control the hot air delivery heater so as to maintain the temperature of the hot air at a predetermined constant value after it has been used to dry the yarn. The present invention will be described in more detail below with reference to embodiments shown in the accompanying drawings.

An airflow outlet 3 is connected to a fan 9 and a heater 7 through an airflow duct 4 in a drying chamber 1 formed to allow the sizing yarn Y to run, and an airflow suction port 5 is connected to a heater through a suction duct 6. 7 is connected.

Furthermore, a temperature sensing element 11 such as a thermocouple is provided near the airflow suction port 5, and its output is input to a heater controller 13.

Further, the output side of the heater controller 13 is connected to the heater 7. That is, hot air heated by the heater 7 is accelerated by the fan 9 and is blown out from the airflow outlet 3 into the drying chamber 1 via the outlet duct 4.

Subsequently, the hot air is used to dry the sized yarn Y in the drying chamber 1 and is deprived of thermal energy, after which it is configured to circulate again from the airflow suction port 5 to the heater 7 via the suction duct 6. . Further, the heater controller 13 functions to control the heater 7 so as to maintain the airflow temperature in the area where the temperature sensor 11 is provided at a constant temperature predetermined by a signal from the temperature sensor 11. The effects of the present invention having the above configuration will be explained next. When the running speed of the sized yarn Y is high and a large amount of thermal energy is required to dry the yarn Y, a large amount of thermal energy is taken away per unit time, so the sized yarn inevitably flows through the airflow suction port 5. The temperature of the hot air after being used to dry Y begins to drop.

The temperature sensing element 11 senses this, and the heater controller 13 thereby controls the heater 7 to maintain the temperature of the hot air at the airflow suction port 5 at a predetermined set temperature. As a result, the temperature of the hot air blown out from the airflow outlet 3 into the drying chamber 1 automatically rises, and the amount of thermal energy supplied into the drying chamber 1 per unit time increases to an appropriate amount. Therefore, it is possible to dry the sized yarn Y at high speed. If the running speed of the sized yarn Y is changed from high to low in this state, only a small amount of thermal energy is required to dry the sized yarn Y, and therefore a small amount of thermal energy is taken away per unit time. The temperature of the hot air flowing into the airflow suction port 5 inevitably begins to rise.

Since the temperature sensing element 11 senses this, the heater controller 13 controls the heater 7 to maintain the temperature of the hot air flowing through the airflow suction port 5 at a set value. As a result, the temperature of the hot air blown into the drying chamber 1 from the airflow outlet 3 decreases, and the amount of thermal energy supplied into the drying chamber 1 per unit time decreases.

Therefore, the sized yarn Y can be dried at low speed without damaging the yarn Y due to heat. In addition, when the sized yarn Y is run very slowly or stopped, the amount of thermal energy required per unit time is very small, so the airflow outlet is The temperature of the hot air blown out from the airflow suction port 3 decreases and becomes almost the same as the temperature of the hot air at the airflow suction port 5.

Therefore, if the temperature of the hot air at the airflow suction port 5 is set to a value that does not affect the yarn, there is no risk of adverse effects of heat on the yarn Y even during very slow drying or when the drying process is stopped. . Furthermore, when performing high-speed drying, the temperature of the hot air introduced into the drying chamber 1 from the airflow outlet 3 rises, but since a large amount of glue adheres to the sized yarn Y and is in a wet state, it has an adverse effect on the yarn. will not be given. In particular, if the airflow outlet 3 is provided on the yarn introduction side in the drying chamber 1, there will be no problem at all. In addition, if a hot air dryer is used to pre-dry the sized yarn and the main drying is performed using a roller dryer, it is necessary to completely dry the glue attached to the yarn Y during the pre-drying stage. This is not a problem because there is no As is clear from the above explanation, a temperature sensing element was installed near the air suction port of the drying chamber to maintain the temperature of the hot air used to dry the sized yarn at a constant value, thereby increasing the drying speed of the sized yarn. Even when the speed is changed from low speed to high speed or from high speed to low speed, the appropriate thermal energy necessary for drying the yarn is automatically supplied into the drying chamber.

Furthermore, drying efficiency can be greatly increased without the need to make the drying chamber longer or increase the speed of hot air as in conventional hot air dryers. Furthermore, the conventional hot air dryer has the advantage that it can be easily improved by simply changing the location of the temperature sensing element near the airflow suction port.

[Brief explanation of drawings]

The accompanying drawings are illustrations of embodiments of the invention.

Claims (1)

[Claims] 1 Hot air for sizing yarn equipped with a hot air drying chamber that has an airflow outlet and a suction port and has a temperature gradient that decreases from the former side to the latter side, and the gradient changes depending on the yarn speed. Hot air drying of sized yarn in a dryer, characterized in that the temperature of the hot air near the suction port is sensed and the heating of the airflow sent to the air outlet is controlled so that the temperature of the hot air is within a certain range. Method.