JPS58112029A - Apparatus for deodorizing dry exhaust gas of offset rotary press - Google Patents

Abstract

PURPOSE:To suppress the consumption of energy to the minimum limit, by enabling the efficient deodorizing treatment of an exhaust gas. CONSTITUTION:This deodorizing apparatus is constituted by perceiving such a fact that reaction heat in a catalyst is proportioned to the concn. of an ink solvent component in an exhaust gas and, based on the measured value of said reaction heat, an exhaust amount and a heating amount are determined. Therefore, thermometers 37, 38 are respectively provided to the front and the rear positions of the catalyst 32 to measure temps. T1, T2 prior to and posterior to catalytic reaction and T2-T2 is set as the substitute characteristic value of the concn. of the ink solvent component. T1 and T2 are put in a speed control part 39, a temp. control part 40 and a damper control part 41 and the control part 39 increases and decreases the exhaust amount due to a fan 34 when T2-T reaches a set value or more. On the other hand, when T1 becomes abnormally high, an exhaust pipe 43 is provided between the catalyst 32 and a heat exchanger 33 in a bypass fashion and exhaustion is controlled by the damper control part 41 in such a manner that a damper 46 is opened to discharge the exhaust gas to the atmosphere through the exhaust pipe 43 without passing the same through the heat exchanger 33.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a deodorizing device for dry exhaust gas of a rotary offset press.

In printing using an offset rotary press, it is necessary to instantaneously dry the ink on printing paper that is transported at high speed, so ink that dries by evaporating the solvent in the ink at high heat is usually used.

The solvent evaporated in the drying device is sent to the deodorizing device, where it is heated, deodorized with a catalyst such as a platinum catalyst, and then exhausted into the atmosphere. Since a considerable part of the supplied thermal energy and the thermal energy supplied within the deodorizing device will also be exhausted, there is currently a tendency to reduce the exhaust amount as much as possible to reduce exhaust loss. If only the exhaust track is reduced, the concentration of ink solvent components in the exhaust gas will rise unnecessarily, reaching the lower explosive limit in some cases, and high-concentration ink solvent gas will leak out from the printing paper inlet and outlet of the dryer. In addition, if the concentration of ink solvent gas increases in the deodorizing device itself, self-combustion may start in the heat exchanger or catalyst, creating a risk that the device will be heated, or this heating As a result, the exhaust capacity of the exhaust fan (which decreases as the temperature rises as a characteristic of the fan) decreases, the negative pressure inside the device decreases, and a large amount of exhaust gas flows out from the printing paper inlet and outlet of the dryer. There are drawbacks.

The present invention has been made in order to eliminate the drawbacks of the prior art, and is a method for dry exhaust gas from offset rotary presses that enables efficient deodorization of exhaust gas and minimizes energy consumption. The present invention provides a deodorizing device.

The present invention will be explained in detail below based on embodiments of the drawings.

The present invention is a heat exchanger that heats the exhaust gas sent from the drying device using the thermal energy of the deodorized exhaust gas that has passed through the deodorizing catalyst, with thermometers that measure the exhaust gas temperature placed before and after the deodorizing catalyst. An exhaust pipe is installed between the deodorizing catalyst and the heat exchanger to directly release the deodorized exhaust gas from the deodorizing catalyst into the atmosphere, and the exhaust gas heated by the heat exchanger is sent to the deodorizing catalyst. A blower and a heating device that heats the exhaust gas to a temperature that allows a catalytic reaction are installed, and the temperature is measured with thermometers placed before and after the deodorizing catalyst. The present invention is a deodorizing device for dry exhaust gas of an offset rotary press, which controls the blowing device and the heating device based on the determined values, and also adjusts the opening and closing of the exhaust pipe.

FIG. 1 is an explanatory diagram of a deodorizing device according to the present invention connected to a drying device of an offset rotary press, where (Al refers to the drying device and (Bl refers to the deodorizing device).

First, the drying device (N) that is important to the present invention will be explained, but the drying device connected to the present invention is not limited to this in any way (it is applicable to any type of drying device). In the drying device (A), (11 is a peripheral wall, which is covered with a heat insulating material such as rock wool, and prevents the heat inside the drying device from dissipating to the outside.)
A printing paper inlet (4) is opened on the offset rotary press side of No. 11, and a printing paper outlet (4) is opened on the opposite side, that is, on the paper discharge device side.
5) is open.

The shapes of the printing paper inlet (4) and the outlet (5) are horizontally long rectangles. Printing paper inlet (4) and outlet (5) to prevent temperature drop
Shutters (7) and (8) operated by a power device such as an air cylinder are installed at the top and bottom of the dryer, and are opened wide only when the printing paper (b) is passed through the dryer for the first time. ), (8) in the closing direction to make the gap between the stamp 11 paper (4) and the exit (5) as small as possible. In a preferred embodiment, the shutters (7) and (8) allow the vertical distance between the printing paper population (4) and the outlet (5) to be 10 to 30 cm.
■The width can be adjusted.

A partition wall (2) is provided in the center of the drying device.
As a result, the drying apparatus is divided into a first drying zone I and a second drying zone (2).

In the center of the partition (2) is a horizontally long rectangular printing paper hole (
6) is formed.

The first drying zone and the second drying zone are ventilation pipes (3).
A damper 09 is disposed in the middle of the ventilation pipe (3) so that it can be opened and closed. In addition, exhaust pipes (9) and 001 are provided in the first and second drying zones, respectively, and these exhaust pipes (9) are connected to the αOK beam deodorizing device (Bl). A damper (141) is provided to control its opening and closing.

The first drying zone and the second drying zone each include a heating device, a blower device, or a burner (181, an α9 and a motor (
2, fans (231 driven by
The air in the drying zone heated by 1% A9 is blown onto the paper surface by the fan ■, +211 to print @
11 papers (b) will be dried. Fan (fuchi,
(The wind speed of 211 is adjustable, and in this example it is 50 m
Good results have been obtained at wind speeds of /S to 70m/S.

In addition, the combustion state in burner Q8)% (19) is determined by setting the paper surface temperature based on the paper surface temperature measured by the printing paper surface thermometer tte, such as an infrared type surface thermometer, placed immediately after the printing paper outlet (5). (171).That is, if the combustion state (that is, the amount of thermal energy supplied)
Assuming that is constant, the printed matter with a large amount of ink will have a large amount of solvent, and as a result of the evaporation of the solvent, a large amount of heat energy will be taken away and the paper surface temperature will decrease, and conversely, the printed material with a small amount of ink will have a large amount of solvent. In this case, less solvent is needed, and a smaller amount of thermal energy is required to evaporate the solvent, which increases the temperature of the paper surface accordingly. In this way, the combustion state can be controlled based on the temperature of the paper surface immediately after drying, and the temperature of the paper surface immediately after drying measured by the thermometer (161) can be adjusted to the temperature (
In a preferred embodiment, the temperature is set at 110'C to 13o C) and when the paper surface temperature falls below the set temperature, the burner (181 or a9) increases the amount of combustion (tM) to spray thermal energy onto the printing paper (tM). If the paper surface temperature rises above the set temperature, excessive thermal energy is being supplied, so by forming a so-called feedback loop that reduces the combustion amount of burner 0 & or α9, the paper surface temperature increases. It can maintain a constant temperature and always perform good drying.

Furthermore, in the present invention, burner a9 is set to operate following burner a&. That is,
Fig. 2 is an explanatory diagram showing the combustion state of burners Q81 and a9, where the vertical axis represents the burner opening degree, and the horizontal axis represents the burner combustion instruction degree based on the feedback system from the surface temperature described above. Burner OgJ is shown, and ■ is burner a9.

ing. As printing begins, burner combustion is instructed, and as a result, the temperature of the first drying zone I rises, and hot air is blown onto the paper surface marked @11 by the fan ①, increasing the temperature to 4°.

The heated air in the first drying zone I is not directly exhausted, but is sent to the second drying zone IIK through the ventilation pipe (3) by closing the damper a11 and opening the damper θ. In general, exposing the printed paper surface to higher temperatures than necessary for a long period of time causes wrinkles, blisters, etc., which is unfavorable in terms of print quality. In (2), hot air at a temperature lower than that in the first drying zone 1 is blown onto the printing paper to cause the temperature of the ink surface to penetrate into the inside of the ink. In one embodiment of the invention, the temperature in the first drying zone I is 240°C;
That in the second drying zone ① is 200°C.

For this reason, as shown in FIG. 2, the burner u! Since burner J is set to open with a delay compared to burner 081, the amount of ink on the printed paper is small and burner a81 opens.
If the temperature of the paper surface reaches the set temperature even when the paper is burned, the burner α9 may not be opened and only the heated air sent from the first drying zone I may be blown onto the printed paper surface. Burner Q! The opening degree of J can be kept small, resulting in less fuel consumption.

In this manner, the air heated for drying the printing paper in the first and second drying zones is transferred to the damper 02° (141°).
By opening , the air passes through the exhaust ducts 01 and a3, and -
It is sent to the deodorizing equipment and valve belt rumor 4≠. In addition, - trachea (
9) In the first drying zone I, when the amount of evaporation of the ink solvent is large and the concentration of the ink solvent component increases abnormally, the damper (Ill) is opened and used only when the concentration of the ink solvent component increases abnormally. , is used to send some hot air directly to the deodorizing equipment.

Next, a deodorizing device according to the present invention will be explained.

01) is the peripheral wall of the deodorizing device (Bl), and like the peripheral wall (1), it is covered with a heat insulating material such as rock wool.The exhaust gas sent through the exhaust duct (13) is first passed through the heat exchanger (c). This heat exchanger (c) uses the deodorized untreated exchanger from the exhaust duct (131) to transfer the thermal energy of high-temperature exhaust gas that has passed through a catalyst 02 (described later) and has been deodorized.

Following the heat exchanger 031, a blower (fan) (b) driven by a variable speed motor C5 is installed, and a heating device (burner) (g) to which fuel (for example, liquefied natural gas) and air are supplied. will be installed. The fan C14) determines the exhaust air volume of the drying device and the deodorizing device, and the burner (to) heats the exhaust gas to the temperature required to carry out the catalytic reaction by the catalyst 02) described later. . The catalyst c32 is for deodorizing exhaust gas containing a large amount of ink solvent components, and in the present invention, a platinum catalyst having a structure in which platinum is coated on honeycomb ceramic is used. In the catalyst (33), the ink solvent components in the exhaust gas react and are deodorized and generate heat, so the temperature of the exhaust gas increases in proportion to the concentration of the ink solvent components before and after passing through the catalyst. The deodorized high-temperature exhaust gas undergoes heat exchange through the aforementioned heat exchanger (421) and is then discharged into the atmosphere through the exhaust pipe (421).

By the way, as described in the prior art, there is currently a trend to reduce the exhaust volume in order to reduce exhaust loss as much as possible. However, if the exhaust amount is reduced unnecessarily, the amount of ink applied on the printed paper surface will be in a state of concern.

Therefore, it is important to determine the exhaust amount according to the increase or decrease in the concentration of the ink solvent component in the exhaust gas, in other words, to determine the exhaust amount according to the ink application 11Vc on the printing paper surface.

The present invention focuses on the fact that the reaction heat in the catalyst (33) is proportional to the concentration of the ink solvent component in the exhaust gas, and the exhaust air volume and heating amount are determined based on the measured value of this reaction heat. It is something.

For this purpose, thermometers (for example, thermometer 07) are installed at the front and rear positions of the catalyst G2, and the temperature of the exhaust gas before the catalytic reaction (T,) and the temperature after the catalytic reaction (T,) are installed. Measure. Here, the temperature range (temperature range) needs to be approximately 650°C in order to cause the ink solvent component to react with the platinum catalyst, and the temperature range (
T2) is the temperature (TI, ) plus the catalytic reaction temperature increase of the ink solvent component, and it increases or decreases in proportion to the concentration of the ink solvent component, so these temperature differences T, -T,
can be used as a substitute characteristic value for the concentration of the ink solvent component (ie, the amount of ink applied on printed matter).

The values of these temperatures (+r,') and (T2) are determined by the speed control unit C3! J, Temperature control section (four-turn damper adjustment section (manually controlled by 4υ), the number of rotations of motor G (i.e., exhaust air volume), the opening degree of burner C (turn), and the opening/closing of damper (46) are adjusted.

That is, in the speed control unit 09, when the temperature difference T; -T between (T1) and (T2) increases beyond the set value, the motor (3
! An order is issued to increase the rotation speed of the dryer (N entrance (4), (
By increasing the number of intake valves for outside air from 5), the ink solvent concentration can be diluted and the heat of reaction in the catalyst C3'lJK can be reduced, and undesirable conditions such as explosions can be avoided. On the other hand, if the amount of ink on the printing paper is small and the temperature difference T2 - T is less than the set value, this means that there is a lot of exhaust loss, so the exhaust air volume should be reduced (and the exhaust loss should be minimized). I can do it.

On the other hand, in the temperature control section (41), since it is necessary to maintain the temperature of the exhaust gas sent to the catalyst 03 at a temperature (approximately 350 degrees Celsius) at which a catalytic reaction is possible, a burner (41) for heating the exhaust gas is installed.
It functions to adjust the temperature (TI) K based on the opening degree (to).

That is, if the temperature (TI) just before the catalytic reaction has not reached about 350°C, the temperature control section (4) will output a signal.
Combustion occurs in the burner, and the fuel supply is controlled according to the temperature to adjust the combustion state. When the temperature (T1) reaches approximately 550°C, combustion in the burner (to) stops. In the present invention, as mentioned above, a highly efficient heat exchanger (c) is used, and the exhaust air volume by the fan (incorporated) has a temperature difference of T27 T.
The temperature (
T1) is almost always maintained at about 550°C, and therefore the burner is often in a combustion-stopped state.

There is a risk of loss, and more heat exchange than necessary will be performed. In order to prevent this, an exhaust pipe (43) is provided as a bypass between the catalyst zero area and the heat exchanger (2), and the damper (46) is opened when the temperature difference T, -T exceeds a certain value. The damper controller (40) adjusts the exhaust gas so that part or all of the exhaust gas is discharged into the atmosphere through the exhaust pipe (43) without passing through the heat exchanger (c).

Furthermore, when printing is stopped, there is no need to perform deodorizing treatment because drying is naturally not performed, but once the deodorizing equipment has cooled down, heating with a burner is required to raise the temperature to the point at which catalytic reaction is possible again. This requires a large amount of time and energy loss. For this reason, while printing is stopped, the dampers (4) (4e) are closed, dampers (4η) are opened, and the ventilation pipe (44) is opened to circulate exhaust gas within the deodorizing device and maintain a high temperature state. has been done.

When the above-mentioned drying device was attached to the deodorizing device according to the present invention and the deodorizing device was actually operated through printing B size tTil1 paper, the following results regarding fuel consumption were obtained.

Drying device; Operating time 251H Fuel consumption 2950.2m' Fuel consumption rate □= 11. y 5771'/H51 11,75 go/H x 0.66 = Z7557F17H deodorizing device; Operating time 385H Fuel consumption gl s 31.7.1 Fuel consumption rate □ = 1.387F! ”/H85 1,58m7H×o, 66=o, qlzyH-where,
The value 0.66 is an area correction value for comparison with the case where A-size printing paper is passed.

On the other hand, the results regarding fuel consumption when the conventional drying and deodorizing device was operated through A-size printed l1iIJ paper are as follows.

Drying equipment; operating time! 1418.9H fuel consumption
53029.4 m Fuel consumption rate □=ts, smn H 3418.9 Deodorizing device: Operating time 4605.9H Fuel consumption 1
9001.1 Fuel consumption rate Go 7, = 4.1 mH As is clear from these results, according to the present invention, it is possible to significantly save fuel compared to the prior art.

As described above, in the present invention, thermometers are arranged before and after the deodorizing catalyst, and the temperature increase due to the catalytic reaction is measured as the concentration of the ink solvent component in the exhaust gas (i.e., the amount of ink applied on the printed paper surface).
Since the speed control section adjusts the exhaust air volume based on this value, it is possible to operate with the lowest possible exhaust volume for the concentration of ink solvent components in each exhaust gas. , exhaust loss can be minimized. Therefore, the power consumption for exhaust can be greatly reduced.

In addition to the low exhaust air volume, the heat exchanger has high efficiency (
70%), the exhaust gas leaving the heat exchanger has already reached a temperature that allows the catalytic reaction, and there is almost no need to reheat it. The amount can be significantly reduced by -M.

In addition, by designing an exhaust pipe between the catalyst and the heat exchanger, it is possible to release exhaust gas directly into the atmosphere without passing through the heat exchanger at abnormally high temperatures, thereby preventing damage to the heat exchanger. This makes it possible to avoid excessive heat exchange.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is an explanatory diagram schematically showing the structure of a drying device and a first odor device, and
The figure is an explanatory diagram showing the combustion state of the heating device in the drying device. 01)...Surrounding wall (c)...Heat exchanger (
B)...Fan (To)...Burner (3)
7), (to)...Thermometer (3I...Speed control section (4[)...Temperature control section (41)...
Dan (-control unit-...drying device (B)...
・Patent applicant for deodorizing device

Claims (1)

[Claims] Thermometers are placed before and after the deodorizing catalyst to measure exhaust gas temperature, and a heat exchanger is installed to heat the exhaust gas sent from the drying device using the thermal energy of the deodorized exhaust gas that has passed through the deodorizing catalyst. , an exhaust pipe is provided between the deodorizing catalyst and the heat exchanger to directly release the deodorized exhaust gas from the deodorizing catalyst into the atmosphere, and a blower device that further sends the exhaust gas heated by the heat exchanger to the deodorizing catalyst. and installing a heating device that heats the exhaust gas to a temperature that allows a catalytic reaction, and controlling the front and rear blower devices and the heating device based on the values measured by thermometers placed before and after the deodorizing catalyst. A deodorizing device for dry exhaust gas of an offset rotary press, which adjusts the opening and closing of the exhaust pipe.