JPH022707B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention mainly relates to a drying oven equipped with a deodorizing device for a printing press that dries ink by blowing hot air onto a strip of printed matter.

[Prior art and its problems]

As a drying oven with a deodorizing device which is integrally equipped with a deodorizing device and uses the heat generated by the deodorizing device as a component of hot air for drying, the applicant has proposed the invention in Japanese Patent Application No. 111689/1989 (Japanese Patent Publication No. 17230/1983). Title: Drying oven for printed matter and Japanese Patent Application No. 111690/1984 (Japanese Patent Publication No. 17231/1983) Title of the invention Discloses a method for controlling exhaust air and circulating air in a drying oven for printed matter.

However, in these methods, all of the recycled high-temperature air from the deodorizing room, excluding the air released to the outside, is sent to the hot air generation room, making it difficult to generate hot air at a low temperature for drying. There were other drawbacks.

In response, the applicant disclosed a device for distributing treated high-temperature hot air in a drying oven equipped with a deodorizing device in Utility Model Application No. 55-41424 (Utility Model Application No. 56-143044). The circulating portion is further divided into the portion that goes to the hot air generation room and the portion that returns to the deodorizing room.When relatively high temperature hot air is used, the entire amount is sent to the hot air generation chamber, and when the temperature is low, e.g.
When hot air below 220°C is required, a damper is installed that opens halfway so that half of the air is returned to the deodorizing room.

As a result, the hot air burner can be well controlled even when using low temperature hot air, and at the same time, the total amount of combustion when using low temperature hot air is smaller than in the conventional case.

However, even with this method, only the low temperature side hot air area was improved step by step; in each range from the low temperature side hot air area to the high temperature side hot air area, the lower the hot air temperature, the lower the used hot air temperature, the so-called return temperature. Since the odor blower also lowers the amount of odor that is sent into the deodorizing chamber, the amount is substantially increased. Therefore, the amount of exhaust gas to the outside increases, and the proportion of heat taken out by the exhaust gas increases, which still has the disadvantage that the total combustion amount of the burner increases.

[Purpose of the invention]

The present invention has been made in view of these points, and the amount of exhaust gas is constant regardless of the high or low temperature of the hot air used, thereby preventing the waste of exhaust gas from increasing due to the low hot air temperature, and increasing the temperature of the hot air. To provide a drying oven with a deodorizing device for a printing press that eliminates the blowing of white smoke from the entrance and exit of the drying oven when the temperature is high and has extremely high thermal efficiency.

[Summary of the invention]

In order to achieve the above object, the drying oven with a deodorizing device for a printing press according to the present invention is equipped with a detector that refluxes a part of the used hot air used for drying and detects the temperature of the used hot air. A reflux path;
A deodorizing chamber has a built-in catalyst that decomposes the used hot air that flows in from this reflux passage, and the treated high-temperature hot air that is sent from this deodorizing chamber through the delivery passage and the untreated used hot air are mixed together. and a hot air generation chamber that heats the mixed air using a built-in burner to produce drying hot air, and a hot air generation chamber that branches off from the middle of the sending flow path to guide the treated high temperature hot air to the middle of the reflux path. The processed high-temperature hot air is supplied to the delivery flow path and the branch flow path based on the temperature detected by the temperature controller provided at the branch part of the branch flow path and connected to the detector. It is characterized in that it is formed with a damper that adjusts the ratio of the inflow amount.

〔Example〕

The present invention will be explained based on embodiments and with reference to the drawings.

In FIG. 1, a hot air generation chamber 2 in a drying oven 1 is shown.
is equipped with a burner 3, and the used hot air 4 returning from the drying oven 1 and the smoke exhaust hood 5 are installed in the hot air generation chamber 2.
A mixture of the suction air 6 and the treated high-temperature hot air 8 from the deodorizing chamber 7 of the deodorizing device is blown out from the hot air blowing nozzle 10 via the hot air circulating blower 9 to the strip-shaped printed matter 11 as drying hot air 12. It's becoming like that. In other words, the treated high-temperature hot air 8 sent out from the deodorizing chamber 7 is mainly sent to the hot air generation chamber 2 through the sending flow path, and further heated by the burner 3 to become drying hot air 12, which is then sent to the hot air blowing nozzle. 10.

Then, a signal is given to the control motor 13 by a temperature controller (not shown) to automatically control the opening degree of the fuel control valve 14 of the burner 3 so that the hot air 12 for the drying oven reaches a desired set temperature TC. ing.

The used hot air that returns from the drying oven 1 becomes the hot air 4 that goes to the hot air generation chamber 2 and a portion of the hot air 4', and this hot air 4' is refluxed into the deodorizing chamber 7 of the deodorizing device through the reflux path. . That is, the hot air 4' enters the odor collecting chamber 15, passes through the filter 15, mixes with treated high temperature hot air 31, which will be described later, and is sent to the deodorizing chamber 7 by the odor blower 17.

A preheating burner 18 is provided in the deodorizing chamber 7.
A mixture of the used hot air 4' and the like containing solvent vapor is heated in a catalyst layer 19 provided in the deodorizing chamber 7 to a temperature sufficient for an oxidation reaction.

The combustion of the preheating burner 18 is controlled by giving a signal to the control motor 21 by a temperature controller (not shown) so that the temperature obtained by the detector 20 that detects the preheating temperature TA of the deodorizing chamber 7 is maintained at the set value. This is done by automatically adjusting the opening degree of the fuel regulating valve 22 of the preheating burner 18.

The treated high-temperature hot air 23, which has passed through the catalyst layer 19 and been purified by the oxidation reaction of the contained solvent vapor and has become high in temperature, is sent to the first branch part 24 of the duct connected to the deodorizing chamber 7 by a damper 25. Half of the air is discharged to the atmosphere as exhaust gas 26, and the remainder is returned to the system as circulating high-temperature hot air 27.

The high-temperature circulating hot air 27 is directed to the hot-air generation chamber 2 by a damper 30 driven by a control motor 29 provided in the second branch 28 .
and high-temperature hot air 31 directed toward the odor collection chamber 15.

As described above, the high-temperature hot air 31 heading toward the odor collection chamber 15 merges with the used hot air 4' returning from the drying oven 1 in the odor collection chamber 15 to form a mixture, which is then sent to the deodorization chamber 7 by the odor blower 17. Sent.

The temperature TS of the air-fuel mixture sent from the odor collection chamber 15 by the odor blower 17 is detected by a temperature detection detector 32 provided in the duct and is sent to a temperature controller 33. This temperature controller 33
sends a signal to the control motor 29 provided in the second branch 28 to automatically adjust the opening degree of the damper 30 in order to automatically maintain the detected temperature TS of the air-fuel mixture at the set value, and 30 to operate properly.

The above is an explanation of the hot air circulation system including the heating or distribution control system according to the present invention.

Next, regarding fresh air, the first branch 2
A heat exchanger 3 is installed in the exhaust duct 34 that exits from the exhaust duct 4 to the outside.
5 is incorporated, and the fresh air sent by the combustion blower 36 passes through this heat exchanger 35 and is warmed, and then is passed through the combustion air duct 37 to the preheating burner 18 of the deodorizing chamber 7 and the hot air generation chamber 2. is sent to burner 3. Further, a part of the combustion air duct 37 is further branched and connected directly to the hot air generation chamber 2,
The amount going to the preheating burner 18 is adjusted by a damper 38 which is opened and closed by an air cylinder.

Next, the effects of the present invention will be explained in detail.

First, the temperature controller 33 is set so that the temperature TS of the mixture after merging in the odor collection chamber 15 is, for example, 250°C.
Set with .

The used hot air 4' entering the odor collection room 15 is 150℃
~200℃. On the other hand, the high temperature hot air 31 is around 350°C. If the temperature TS of the mixture obtained by combining these two is lower than the set value, the temperature controller 33
sends a signal to the control motor 29 and adjusts the opening degree of the damper 30 to increase the amount of high-temperature hot air 31. Conversely, if the temperature TS of the mixture is higher than the set value, the amount of high-temperature hot air 31 is decreased. The opening degree of the damper 30 is controlled as follows. As a result, odor blower 1
Temperature of the mixture sent to the deodorizing chamber 7 by 7
TS is always maintained at the set value.

In general, even if the apparent air volume of a blower is constant, if the temperature of the air passing through it changes, the mass or air volume converted to standard conditions (so-called Nm ³ /
min) will change.

Furthermore, in the past, there was no device for keeping the temperature TS of the air-fuel mixture sent to the deodorizing chamber 7 by the odor blower 17 constant, as in the present invention.
When the hot air temperature for drying was set high, the temperature of the air flowing into the deodorizing chamber was also high, and when the hot air temperature was set low, the temperature was low. As a result, in the past, the actual amount of air sent into the deodorizing chamber was small when the hot air temperature was high, and increased when the hot air temperature was low, causing the above-mentioned inconveniences. Such inconvenience does not occur in the invention.

Furthermore, in the conventional example, the amount of exhaust gas 26 released into the atmosphere out of the treated high-temperature hot air 23 that has passed through the deodorizing chamber 7 and has been purified is
Since the opening degree of the damper 25 in the branch part 24 is a constant ratio to the passing air volume, the exhaust gas 2
The amount of 6 is small when the hot air temperature is high, and becomes substantially large when the hot air temperature is low.

Now, the amount of this exhaust gas 26 is expressed in standard conditions as E Nm ³ /min Air supplied to preheating burner 18 W ₁ Nm ³ /min Air supplied to hot air burner 3 W ₂ Nm ³ /min From flue gas hood Assuming that the air taken in is Z Nm ³ /min and the air from the entrance and exit of the dryer is R Nm ³ /min, the following equation holds true since the air volume entering the system is equal to the air volume exiting the system.

E=W ₁ +W ₂ +Z+R However, the amount of air directly fed into the hot air generation chamber 2 from the combustion air duct 37 is assumed to be 0.

Therefore, the suction amount R from the dryer entrance is R = E-(W ₁ + W ₂ + Z), and if the amounts of W ₁ , W ₂ , and Z are constant, the suction amount R from the dryer entrance is equal to the displacement E. When you change something, you can see that it changes by the amount that changed.

That is, in conventional apparatuses, when the hot air temperature was set low due to low printing speed, etc., the amount of exhaust air was increased, and therefore the amount of suction from the inlet and outlet of the drying oven was also large. This causes the inside of the drying oven to cool down even more.
This increases the amount of fuel in the burner and increases the amount of heat carried away by the exhaust gas, resulting in energy losses.

In the present invention, the temperature of the air sent into the deodorizing chamber 7 can be kept constant regardless of whether the hot air temperature is high or low, so the amount of suction R from the dryer entrance and exit can be maintained constant.
In addition, it has become possible to keep the exhaust air volume E at a constant value of the minimum necessary value, so that the inside of the drying oven is not unnecessarily cooled, and the amount of heat taken out by the exhaust gas can be suppressed to the minimum.

Next, consider printing speed.

When the printing speed is increased, the amount of heat per hour to be transferred to the strip-shaped printed material 11 increases, and the temperature of the hot air for drying must be increased, so at first glance it seems that the hot air burner 3 has to burn more. However, since the air-fuel mixture sent into the deodorizing chamber 7 by the odor blower 17 has a constant temperature and constant quantity, the amount of heat to heat it to the preheating temperature TA is constant, and the reaction temperature after passing through the catalyst layer 19 is lower than that of the solvent. The temperature becomes high due to the high vapor concentration.

Therefore, the temperature TS of the mixture sent to the deodorizing chamber 7
The amount of high-temperature hot air 31 directed to the odor collection chamber 15 required to maintain the odor collection chamber 15 becomes small, and the high-temperature hot air 8 sent into the hot-air generation chamber 2 becomes higher in temperature and increases in air volume. For this reason, the combustion amount of the hot air burner 3 usually decreases slightly.

Specifically, since the exhaust gas temperature becomes higher, the temperature of the combustion air heated by the heat exchanger 35 also becomes higher, which lightens the burden on the preheating burner 18 and the burner 3. Therefore, as the printing speed increases, the combustion amount of the preheating burner 18 also decreases slightly.

On the other hand, when the printing speed is low and the hot air temperature setting is low, the temperature TS of the air-fuel mixture sent by the odor blower 17 does not change, so the combustion amount of the preheating burner 18 increases by the amount of temperature reduction of the combustion air. However, the hot air burner 3
Although the temperature and quantity of the high-temperature hot air 8 sent into the hot-air generation chamber 2 decreases, the set hot-air temperature is also low, so there is no need to burn it so much, and the disadvantageous ratio when the speed is low is extremely small. .

In general, the amount of exhaust air from the dryer must be sufficient to prevent blow-out at the dryer entrance and exit, and must also be sufficient to maintain the solvent vapor concentration within the dryer within an acceptable range. . If the amount required by the latter is within the amount required by the former, the displacement amount may be determined by the amount required by the former. However, if the amount of solvent vapor in the dryer is expected to be large due to a large amount of ink deposited or a high printing speed, the exhaust amount must be larger than the former.

In the present invention, since the high-temperature hot air 8 that has been processed by the deodorizing device is returned to the hot air generation chamber 2, the amount of used hot air 4' that is sent from the drying furnace 1 to the odor collection chamber 15 to be sent to the deodorizing device is It is larger than the amount of final exhaust 26. Therefore, the solvent vapor concentration can be kept low despite the small final exhaust volume.

As the amount of evaporation of the solvent increases, the temperature of the treated high-temperature hot air increases, and in order to maintain the temperature TS of the mixture sent to the deodorizing chamber 7 at a constant value, the odor collecting chamber 15 is required.
The amount of treated high-temperature hot air 31 going to the drying oven 1 decreases, and the amount of used hot air 4' increases, so even if the amount of solvent evaporation increases, the concentration of solvent vapor in the drying oven 1 only increases slightly. It has characteristics.

Another new feature of the present invention is that the preheating burner 8 in the deodorizing chamber 7 does not need to be burned when the concentration of solvent vapor in the used hot air becomes high.

That is, when the amount of ink applied is large and the printing speed is high, the concentration of solvent vapor contained in the used hot air 4, 4' becomes high, and the reaction temperature TB when passing through the catalyst layer 19 becomes high.

Therefore, when the reaction temperature TB reaches a set temperature on the high temperature side, for example 420° C., the set value of the temperature TS of the air-fuel mixture sent by the odor blower 17 is automatically raised to the preheating temperature TA.

To explain this behavior in more detail, the reaction temperature
When it is detected that TB has reached 420°C, the set value of the air-fuel mixture temperature TS by the temperature controller 33 is changed to
The preheating temperature TA is changed to, for example, 300°C. As a result, the opening degree of the damper 30 is controlled via the control motor 29, and the odor collection chamber 1
The temperature TS of the mixture of the used hot air 4' and the high temperature hot air 31 in the hot air 5 is set to the newly set 300°C. At the same time, the control motor 21 fully closes the combustion adjustment valve 22, cuts off the fuel supply to the preheating burner 18 to stop combustion, and switches the damper 38 provided in the duct 37 that leads the combustion air _W1 to the combustion air W1. The supply of air is stopped and this amount is sent to the hot air generation chamber 2.

In this way, even if the preheating burner 18 does not burn, the temperature TS of the air-fuel mixture entering the deodorizing chamber 7 becomes a high temperature of 300°C, which is suitable for the catalytic reaction, and the oxidation reaction in the catalytic layer 19 continues due to the self-combustion phenomenon. Continued.

In the hot air generation chamber 2, the amount of incoming high temperature hot air 8 decreases, so the amount of combustion increases slightly;
Overall, the combustion amount decreases.

Whether the temperature TS of the air-fuel mixture entering the deodorizing chamber 7 is controlled to a low temperature or the deodorizing device is caused to self-combust, there is no need for the operator to operate the damper 30, which reduces the burden on the operator.

Figure 2 shows a comparison regarding the amount of combustion. This is a comparison. In addition,
The reason why the combustion amount particularly decreased from 450 rpm to 500 rpm in the c curve is due to self-combustion.

〔Effect of the invention〕

According to the present invention, the exhaust gas is naturally discharged without any pollution, and has the following advantages.

In other words, since the temperature of the air-fuel mixture flowing into the deodorizing chamber is constant, if the solvent concentration in the furnace increases due to printing conditions, the temperature of the treated high-temperature hot air will increase.
The amount of treated hot air that is branched from the delivery channel to the reflux channel is reduced, and the amount of treated hot air that is sent for drying is increased, which works to lower the solvent concentration in the furnace. The amount of heat can be minimized, and the amount of heat transferred to the hot air generation chamber can also be increased, making it possible to provide a drying oven with extremely high thermal efficiency.

The above advantages can be obtained by adding a small amount of mechanical equipment such as a temperature controller or a detector for detecting temperature, and the effects can be significant.

[Brief explanation of drawings]

FIG. 1 is a sectional view illustrating the structure and function of the present invention, and FIG. 2 is a combustion amount comparison diagram illustrating the energy saving properties of the present invention. 1... Drying oven, 2... Hot air generation chamber, 3... Burner, 4,4'... Used hot air, 5... Smoke exhaust hood, 6... Suction air, 7... Deodorizing room, 8,2
3, 31... Treated high temperature hot air, 9... Hot air circulation blower, 10... Hot air nozzle, 11... Band-shaped printed matter, 12... Hot air for drying, 13, 21, 29...
Control motor, 14, 22...Fuel control valve, 15...Odor collection chamber, 16...Filter, 1
7...Odor blower, 18...Preheating burner, 19...
...Catalyst layer, 20...Temperature detector, 24...First
Branch, 25, 30, 38... Damper, 26...
Exhaust air, 27... Circulating high temperature hot air, 28... Second branch, 32... Temperature detector, 33... Temperature controller, 34... Exhaust duct, 35... Heat exchanger, 3
6... Combustion blower, 37... Combustion air duct.

[Claims]

1. A printing device that has a type wheel consisting of a plurality of fingers extending from a central portion and type characters provided on the fingers, and the type wheel is supported by a carriage that moves intermittently along a platen, supporting the fingers. A plurality of central portions are provided, and the type is arranged so as to form a plurality of annular rows concentrically with the rotation center of the type wheel on the tip type portion of the finger extending from each center portion, and the tip type portions are arranged in a common radial direction. a type wheel located on a surface; rotary drive means stationary relative to the carriage for rotationally driving the type wheel; joint means provided between the rotary drive means and the type wheel; and shifting means for shifting the type wheel relative to the rotary drive means to select the plurality of annular columns.