JPS60114297A - Dryer - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a dryer equipped with a heat exchanger, and particularly to a dryer (2) in which completion of drying is automatically detected.

[Technical background of the invention and its problems]

Conventionally, dryers equipped with a heat exchanger (sometimes the air (warm air) discharged from the drying chamber is passed through one ventilation path of the heat exchanger and returned to the drying chamber, and the air outside the machine is (Outside air) is passed through the other ventilation path of the heat exchanger and discharged outside the machine again, allowing the warm air and outside air to exchange heat in the heat exchanger, thereby condensing the moisture in the hot air. Some dryers are designed to return hot drying air to the drying chamber. Conventionally, this type of dryer automatically detects when the drying process has been completed and starts drying operation. Some devices are equipped with a control device that controls the direction in which the machine stops.This control device is equipped with a control device that controls the air flow from outside the machine, that is, outside air, and the drying room after drying the material to be dried in the drying room. Exhaust air (warm air)
The drying operation is stopped when the temperature difference exceeds a predetermined value by detecting the temperature difference between There is a device that detects the difference between the temperature at the outlet and stops the drying operation when the temperature difference exceeds a predetermined value.

However, in the former case, the temperature difference between the outside air and the exhaust air tends to vary depending on the air temperature because the humidity of the air itself is easily affected by the room temperature, and the drying of the material to be dried is affected by the influence of the room temperature. A malfunction sometimes occurred where the drying operation stop time did not match the completion time.

In the latter case, the temperature difference between the temperature at the inlet of the heat exchanger and the humidity at the outlet of the exhaust air changes only slightly between the time when drying is completed and before that. Although the degree of dryness varies greatly, the amount of change in temperature difference is small,
For this reason, there is a risk that the drying operation will be stopped before the drying target reaches the drying completion state, and in general, in any of the above cases, the detection of the drying completion time +tll may be inaccurate.

[Purpose of Hatsuhaku]

The present invention has been made in view of the above circumstances, and its object is to provide a dryer that can stop the drying operation precisely in synchronization with the time when the drying of the material to be dried is completed. It is in.

(Summary of the invention) The present invention includes a J3 equipped with a heat exchanger for exchanging heat between the air discharged from a dry mT5 and outside air, and detects the temperature of the discharged air at the inlet side of the heat exchanger. With,
Detects the temperature on the outer surface side of the heat exchanger that is on the outlet side of the heat exchanger and in the passage of the outside air, and controls the drying operation to be stopped when the temperature difference exceeds a predetermined value. This system is equipped with a control device that allows the temperature difference at the time of completion of drying to be clearly distinguished from the temperature difference before that, without being affected by room temperature. Has characteristics.

(Embodiments of the invention) An embodiment of the present invention will be described below with reference to the drawings.

First of all, in Figs. 1 to 3, 1 is an outer box, in which a drying material inlet/outlet 2 is formed approximately at the center of the front surface, and ventilation holes 3, 4 are formed on both sides of the outer box. Further, one vent hole 5, 6 is formed on each outer side thereof. 7
is the drying material inlet/outlet 2 n A door provided to be closed; 8 is one front cover that covers the vents 3 and 5 from the front in a bag-like manner; 9
is the other 1 which covers the ventilation hole 4.6 from the front like a bag.
It is an iIJ cover. 10 is a ventilation hole 3 inside the outer box 1
A drum support is arranged in an annular manner to surround the inlet/outlet port 2 for the dried material, and a vent hole 11 is provided in the part facing the vent port 3, and the vent port 4 and A required number of ventilation holes 12 are formed in the opposing parts, and a heater 13 is arranged between the ventilation holes 11 and 3. 14 is a drum with an open front. The front opening edge is supported by the drum support 10, and the shaft 15 attached to the center of the rear plate is supported by a support plate 16 horizontally suspended at the rear end of the outer box 1. It is rotatably arranged inside the box 1, and the inside of the drum 14 is used as a drying chamber 17. 18 is a motor arranged at the lower corner inside the outer box 1;
A pulley 19 is attached to the rotating shaft 18a of this, and a belt 20 is stretched between the pulley 19 and the outer periphery of the tram 14, and the drum 14 is rotated by one motor 18. Sea urchin C is here. Note that 21 is a tension pulley provided to apply a constant tension to the belt 20. On the other hand, 22 is a first duct, which communicates at its base with the ventilation port 6 in the outer box 1, and extends upward from there to communicate with the suction port 23a of the casing 23. An impeller 25 attached to a fan shaft 24 is disposed in the casing 23, and an impeller 27 is disposed in a casing 26 arranged in parallel at the front of the casing 23. It is attached and arranged on the fan shaft 24. A pulley 28 is attached to the rear end of the fan shaft 24 that protrudes outside the casing 23, and a pulley 29 is attached to the tip of the rotating shaft 18a of the motor 18. Bells 1-30 are stretched across and 29, so that the impellers 25 and 27 are rotated by the motor 18.

31 is a heat exchanger placed inside and above the outer box 1;
As shown in FIG. 4, a large number of plate-shaped fins 33 are arranged between the upper and lower end plates 32 and 32, separated from each other, and a small number of pipes 34 are installed to pass through the fins 33. It is arranged and configured.

Such a heat exchanger 31 is located at the right end side of the pipe 34.
It is connected to the discharge port 23b of the casing 23 via the connecting tube 35, and is also communicated with the vent 5 via the second duct 36 at the left end side of the pipe 34. With this, the air (warm air) in the drying chamber 17 is discharged from the drying chamber 17 as the impeller 25 rotates, is sucked into the casing 23, passes through each pipe 34, and is further transferred to the second duct. 36 and is returned to the drying chamber 17. On the other hand, the front opening of the heat exchanger 31 is the exhaust port 26a of the casing 2G.
The rear opening is connected to an exhaust port 37 formed in the rear panel of the outer box 1. And 38
is an outside air intake port that is connected to the intake port 26b of the casing 26 and is formed in the front of the outer box 1, and is connected to the filter 39a.
The impeller 27 is covered with a cover 39 having a
With the rotation of
I try to put it out.

Now, in FIGS. 3 and 4, 40 and 41 indicate a part of a control device 48, which will be described later, and 47? A first temperature sensor and a second temperature sensor comprising a first temperature sensor 4.
0 is located near the inlet portion 34a of the pipe 34, which is the inlet side of the exhaust air < warm air) to the heat exchanger 31, and is attached to the inner surface of the fan casing 23. The temperature sensor 41 of No. 2 is thermally attached to the fin 33 on the outer surface side of the heat exchanger 31 located at the outlet portion 34b of the pipe 34 on the outlet side of the heat exchanger 31 and located in the outside air passage. I'm wearing it. Therefore, the first temperature sensor 40 is
The temperature of the exhaust air passing through the heat exchanger 31 is detected at the inlet portion 34a of the pipe 34, and the second temperature sensor 41
At the outlet portion 34b of the pipe 34, the temperature trace on the outer surface of the heat exchanger 31, that is, the temperature of the fin 33 itself is detected.

Next, the electric circuit configuration will be explained with reference to FIG.

42, 43 are power terminals connected to an AC power source (not shown), and 44 are two interlocking switches 4, 4. 45 is a relay, 46 is a relay switch that is closed when the relay 45 is energized, and 47 is a normally closed thermoswitch for ensuring drying temperature. On the other hand, 48 is a control device, which will be described below. That is, 49 is a rectifier circuit, 50 is a constant voltage generating circuit, 51 is a reference voltage generating circuit, 52 is a voltage dividing circuit consisting of the first temperature sensor 40 and the second humidity sensor 42, and 53 is a voltage dividing circuit. Reference voltage generation circuit 51 and voltage dividing circuit 'tB52
54 is a relay that is energized by the drive circuit 55 when a high level signal is output from the comparator 53, and 56 is closed when the relay 54 is energized. 57 is a relay switch that is opened when the relay 54 is energized, 58 is a timer motor, and 5 is a buzzer. Thus, the heater 13, which is the load. Motor 18, relay 45. The timer motor 58 and the buzzer 59 are connected to the fifth power line 60.61 connected to the power terminal 42.43.
As shown in the figure, the power switch 44. Relay switch 46.
They are connected via a thermoswitch 47 and relay switches 56 and 57. Each of the switches 41a and 44b of the power switch 44 is maintained in an open state after being manually turned on, and is opened after the timer motor 58 is energized for a certain period of time.

Now, to describe the effect of the above (growth), now turn on the power switch 4.
4 is opened, the relay 45 is energized and the relay switch 46 is opened, thereby starting the motor 18. Further, in this case, the reference voltage of the reference voltage generation circuit 510 is at a higher level than the detection voltage of the voltage dividing circuit 52, and the comparator 53 outputs a high level signal. Therefore, the relay 54 is energized, the relay switch 56 is opened, the heater 13 is energized and heated, and the relay switch 57 is opened. As the drum 14 is rotated based on the activation of the motor 18, the fan shaft 24 and hence the impellers 25 and 27 are rotated, and the rotation of the impeller 25 causes the air in the drying chamber 17 to flow through the ventilation hole 121. It is sucked into the casing 23 through the vent 4 and the first duct 22 and discharged from the casing 23 as wind, and then passes through the pipe 34 of the heat exchanger 31 to the second duct 362 vent 51 vent 3. This folded air is introduced into the drum 14, that is, into the drying chamber 17 through the heater 13 and the ventilation hole 11, and is turned into warm air by the heater 13 which is in a heat generating state. Supplied. The hot air then removes moisture from the objects to be dried that have been stored in the drying chamber 17 in advance, and then enters the casing 23 from the vent hole 12 through the vent holes 4 and 6 and the first duct 22, and then returns to the drying chamber 17. The cycle of being discharged from the casing 23 toward the heat exchanger 31 is repeated. Therefore, the air discharged from the drying chamber 17, that is, the warm air containing moisture, passes through each vibrator 34 of the heat exchanger 31. On the other hand, as the impeller rotates 270 times, outside air is sucked into the casing 26 from the outside air intake port 38, and this outside air is transferred to the vibrator 3 of the heat exchanger 31.
4, passes between the fins 33 on the outer surface side, and is discharged from the JJ+ air port 37 to the outside of the outer box 1.

Therefore, the moisture-containing heat passing through the inside of the vibrator 34 of the heat exchanger 31 is cooled by the outside air passing through the outside of the vibrator 34. Moisture in the B-air is condensed within the vibrator 34, and as a result, the warm air is returned to the drying chamber 17 in a dry state.

During such drying operation, in the heat exchanger 31 section, the sixth
The humidity changes as shown in the figure are shown. That is, in FIG. 6, the vertical axis represents humidity, the horizontal axis represents drying rate, and,
Characteristic line 1 indicates the humidity on the inlet side of the exhaust air of the heat exchanger 31, that is, changes in the temperature of the exhaust air at the inlet portion 34a of the vibrator 34, and characteristic line T2 indicates the change in the temperature of the exhaust air at the inlet side of the heat exchanger 31. It represents the change in the external surface temperature of the heat exchanger 31 located on the outlet side of the heat exchanger 31 in the outside air passage, and in this case, the humidity of the fins 33. T2 is a change characteristic when the room temperature is normal temperature (20° C.). On the other hand, characteristic line 1. ．． 12 represents the change in the temperature at the inlet side of the exhaust air and the change in Wlff of the fin 33 at the outlet side when the room temperature is 5° C., respectively.

Therefore, if the room temperature is 20℃, drying operation start time -1-8
As can be seen from the characteristic line T1, the temperature of the exhaust air at the inlet portion 34a of the pipe 34 (hereinafter referred to as the inlet side exhaust air temperature) is determined by the temperature of the air supplied into the drying chamber 17.
The temperature of the fin 33 (hereinafter referred to as the exit side fin temperature) that rises as it is heated by and rises at the outlet portion 34b of the pipe 34 located on the outlet side is:
As can be seen from the characteristic line T2, the temperature of the discharged air is lowered through heat exchange with the outside air, so that the temperature of the discharged air on the inlet side rises, although the temperature is lower overall than that of the discharged air on the inlet side.

At this time, the temperature change (characteristic line Tl) on the inlet side is detected by replacing it with a resistance value change by the first temperature sensor 40, and the change in the fin concentration at the outlet side (characteristic line T2) is detected by the second humidity sensor 41. It is detected by replacing it with a change in resistance value.
Now, since the exhaust air temperature on the inlet side and the fin humidity on the outlet side rise almost in the same way, there is no significant change in the temperature difference, and therefore the detected voltage 1i- of the voltage dividing circuit 52 is The base t~ (remains at a lower level than the voltage. During this drying operation!After the Ift period Ts, the moisture absorption action of the warm air on the material to be dried becomes active in the drying chamber 17. The characteristic line T
As can be seen from 1, when the temperature change of the exhaust air on the inlet side is stabilized, the change in the fin temperature on the outlet side is also stabilized, as seen from the characteristic line T2, and no large change is observed in the temperature difference. In this case, the exhaust air coming out of the drying chamber 17 contains considerable moisture.
As mentioned above, the moisture is condensed during heat exchange between the exhaust air and the outside air. Then, when the drying rate of the material to be dried becomes high and the drying completion time Te is reached, wetting due to moisture absorption occurs.
Since the heat release amount of l is small, the inlet side discharge humidity increases as shown by the characteristic line T1, while the outlet side fin humidity increases as shown by the characteristic line T1.
2 shows a downward trend. That is, the discharged air contains moisture taken from the material to be dried, but the amount of moisture is large and approximately constant as long as the drying rate of the material to be dried is low.
It is known that the heat capacity of the exhaust air decreases rapidly as the drying rate increases, and accordingly, the heat capacity of the exhaust air also decreases sharply as the drying rate increases. In addition, when there is a lot of moisture in the exhaust air, latent heat is generated due to the condensation effect due to heat exchange between the exhaust air and the outside air, but when the moisture content decreases, the latent heat also decreases extremely, and as a whole, the exhaust air on the exit side The amount of heat exchanged with the outside air in the fins 33 rapidly decreases, and as a result, the outlet side fin temperature decreases. As the inlet side discharge air temperature increases and the outlet side fin temperature decreases, the temperature difference suddenly increases, that is, the temperature difference exceeds a predetermined value, and the J34 The pull detection voltage becomes higher level than the reference voltage, and as a result, comparator 5
3, an O-level signal is output, and the relay 54 is de-energized. As a result, the relay switch 56 is opened to energize the heater 13, and the relay switch 57 is also opened to energize the timer motor 58 and the buzzer 59, causing the buzzer 59 to sound. and timer motor 58
The timing cam (not shown) is activated by this, and after some time has elapsed, each switch 44a and 44 of the power switch 44 is turned on.
．． b is opened, which causes relay 45 and therefore motor 1
8 is cut off, and the timer motor 58 and buzzer 5
9 is cut off, thereby stopping the drying operation.

Also, when the room temperature is lower than normal temperature, for example about 5°C, the inlet side discharge air temperature is lower overall than when the room temperature is normal temperature (20°C), as seen from the characteristic line L1. , the change characteristics are almost the same as can be seen from the comparison between the characteristic line t1 and the characteristic line T1, and on the other hand, the outlet side fin temperature is also lower overall than when the room temperature is room temperature (20°C). However, its change characteristics are characteristic line t2 and characteristic line T2.
As can be seen from the comparison with
In this case, the difference between the temperature of the discharge air on the artificial side and the fin temperature on the outlet side is also substantially the same as when the room temperature is room temperature, and as the drying rate increases, the temperature difference increases rapidly. Therefore, in this case as well, when the drying rate becomes high and the temperature difference exceeds a predetermined value, the drying operation is stopped.

According to this embodiment, when the drying is completed, J3
Focusing on the fact that the temperature of the discharged air (warm air) rises and, conversely, the temperature of the outlet side fins decreases, the temperature of the discharged air at the artificial part 34a of the pipe 34 of the heat exchanger 31 is measured by the first humidity sensor 4o. A control device that detects the temperature of the fins 33 in the outside air passage of the outlet portion 34b of the pipe 34 on the outlet side, and controls the drying operation to be stopped when the temperature difference therebetween exceeds a predetermined value. 48, the temperature difference at the time of completion of drying can be clearly distinguished from the temperature difference before that point, and it can be detected without being affected by the room temperature. If it is possible to stop the drying operation in synchronization with the exact timing, and as a result, the drying operation will not be prolonged unnecessarily [), there will be problems such as the drying operation being stopped before the material to be dried is dried. It can be lost.

In the above embodiment, the temperature of the pipe 33 at the outlet portion 34b of the pipe 34 is detected.
The temperature on the outer surface of the outlet portion 34b of the vibrator 34 itself may be detected.

Further, in the above embodiment, the air discharged from the drying chamber 17 is passed through the heat exchanger 31 and then returned to the inside of the drying chamber 17. Although the dryer is of the so-called mud air circulation type, the present invention The air (outside air) is passed through one ventilation path of the heat exchanger, heated and supplied to the drying chamber, and the air exhausted from there through the drying chamber is discharged through the other ventilation path of the heat exchanger. It can also be applied to a vortex μm discharge type dryer.

In addition, the present invention is not limited to the embodiments described above and shown in the drawings, and can be implemented with various modifications within the scope of the invention.

〔Effect of the invention〕

As explained above, the present invention provides an IC dryer equipped with a heat exchanger for exchanging heat between air discharged from a drying chamber and outside air. At the same time, the temperature on the outside surface of the heat exchanger is detected at the exit side of the heat exchanger and into the outside air passage, and when the temperature difference exceeds a predetermined value, drying operation is started. (It is characterized by the provision of a 211 device, which stops the process when the drying of the material to be dried is completed.)
It is possible to clearly distinguish and detect the temperature difference between previous temperatures without being affected by the room temperature. It is possible to control the drying process, and as a result, it is possible to prevent the drying operation from being unnecessarily prolonged, and also to prevent problems such as the drying operation being stopped before the material to be dried is dried.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, with the first figure being a front view and the second figure being a front view.
The figure is a sectional view taken along the line I-II in Figure 1, and Figure 3 is a sectional view taken along the line I-1 in Figure 1.
[A line sectional view, Figure 4 is a longitudinal sectional front view of the heat exchanger section, and Figure 5 is a vertical sectional view of the heat exchanger section.
The figure is an electric circuit diagram, and Figure 16 is a temperature characteristic diagram. In the figure, 13 is a heater, 17 is a drying chamber, 18 is a motor, 3
1 is a heat exchanger, 33 is a fin, 34 is a pipe, 40 is a first humidity sensor, 41 is a second temperature sensor, and 48 is a control device. Applicant: Tokyo Shibaura Electric Co., Ltd. Figure 1 Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] 1. In a device equipped with a heat exchanger for exchanging heat between the air discharged from the drying room and outside air, the input 1 of the heat exchanger is
] side (at the same time as detecting the temperature of the discharged air, the humidity on the outside surface side of the heat exchanger at the exit side of the heat exchanger and in the passage of the outside air is detected, and the temperature difference therebetween is greater than or equal to a predetermined value. A dryer characterized in that a control device 211 is provided for controlling the drying operation in a direction in which the drying operation is stopped when .