JP2001260310A - Dampening water filtering device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately filter a moistening water while space-saving at a low cost by holding the water clean and recycling the water. SOLUTION: The moistening water used in an offset printer 101 is guided to a moistening water filtering device 103 via a suction port 1, passed through first and second filters 4, 5 to remove impurities. Thus, the water is circulated in a clean state and can be hence recycled. Further, as the second filter 5, a pleating type filter or more particularly a filter formed in a cylindrical state by gusseting a filter material 4a obtained by mixing a mineral material such as a diatomaceous earth or the like with a nonwoven fabric of a polypropylene fiber or the like is used. Thus, the overall dampening water filtering device 103 can be space-saved at a low cost and can accurately filter.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dampening water filter for filtering dampening water used for offset printing.

[0002]

2. Description of the Related Art In an offset printing press, a dampening solution is used to moisten a non-image area of a printing plate and prevent ink from being applied to the non-image area. The fountain solution is an aqueous solution containing H liquid, isopropylene alcohol, or the like, and is intended to prevent bleeding when transferring the ink or to cool the ink.

By the way, in the process of circulating in the offset printing machine, the dampening solution contains ink particles, paper powder, dust,
Machine oil, washing oil, spray powder to prevent adhesion between papers, etc. are mixed and stained.

If the contaminated dampening solution is circulated in the offset printing press, phenomena such as bleeding, bleeding, and repelling of printed matter are caused, resulting in poor printing. Also, when the temperature of the dirty dampening solution rises, bacteria that have entered from the air proliferate, rot and odor.

[0005]

Heretofore, dirty fountain solutions have been replaced, for example, on a weekly basis. However, since the used fountain solution contains ink particles, oil, and the like, the BOD, COD, and norhex value may reach several times to several tens times the legal wastewater standard value. That is, the used fountain solution is sewage that normally needs to be treated as industrial waste. In fact, there are companies that dispose of such used dirty dampening water in sewage or rivers for disposal.

[0006] Until the dampening solution is replaced, the dampening solution is used as it is, so that the printing quality is degraded, and the stains adhere to the piping through which the dampening solution flows.
The flow of dampening water is obstructed and the cooling efficiency drops.

[0007] Further, replacing the dampening solution one by one requires not only a troublesome operation, but also a stoppage of the offset printing press during the replacement operation, resulting in poor operating efficiency.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems. By filtering a dampening solution, the dampening solution can be kept clean and can be reused. It is an object of the present invention to provide a water filtration device and enhance its function.

[0009]

According to the present invention, there is provided a dampening solution filtering apparatus for filtering dampening water used in an offset printing press, comprising: a first filter; A second filter disposed downstream of the first filter, wherein the second filter is a pleated filter including a filtering material obtained by mixing an inorganic material with a nonwoven fabric. It is characterized by having high filtration accuracy.

Another feature of the dampening solution filter of the present invention is that the nonwoven fabric of the second filter is made of polypropylene fibers.

Another feature of the dampening solution filtration device of the present invention is that the inorganic material of the second filter is diatomaceous earth.

Another feature of the fountain solution filtering device of the present invention is that the first filter is a thread-wound filter in which a non-twisted fiber is wound over several layers.

[0013] Another feature of the dampening solution filtering device of the present invention is that the device has a pressure detecting means for detecting at least the pressure on the upstream side of the first filter or the pressure on the upstream side of the second filter. On the point.

In the fountain solution filtering device of the present invention as described above, when the fountain solution passes through the first filter, relatively coarse impurities such as paper dust and dust are removed. When the fountain solution that has passed through the first filter passes through the second filter, fine impurities that have not been removed by the first filter, such as fine particles such as ink and bacteria, are removed.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a dampening solution filtration device according to the present invention will be described below with reference to the drawings.

FIG. 1 shows a configuration and an installed state of a dampening solution filtration device according to a first embodiment. In FIG.
Denotes an offset printing machine, which includes a plate cylinder 101a, a water boat 101b for storing dampening water, and a roller 101c for guiding the dampening water in the water boat 101b to the plate cylinder 101a. In the offset printing press 101, the dampening water in the watercraft 101b is rotated by the rotation of the roller 101c to cause the plate cylinder 101a to rotate.
It will be guided to the side and will moisten the non-image area.

Reference numeral 102 denotes a dampening water management tank for supplying dampening water to each watercraft 101b of the offset printing machine 101. The dampening water management tank 102 detects the concentration, pH, water temperature, etc. of the dampening solution H liquid, isopropylene alcohol, etc., and replenishes water or adjusts the H liquid, isopropylene alcohol, etc. to adjust them. Replenish or cool the dampening solution.

Reference numeral 103 denotes a dampening solution filtration device according to the present embodiment. In the dampening water filter 103, reference numeral 1 denotes a suction port, and the dampening water used in the offset printing machine 101 is guided through a dampening water management tank 102. Reference numeral 2 denotes a pump, which sucks dampening water in the device 103,
Discharge is performed. Reference numeral 3 denotes a discharge port for returning the dampening water filtered by the apparatus 103 to the dampening water management tank 102.

Reference numeral 4 denotes a first filter, which is a second filter described later.
Has a coarser filtering accuracy than the filter 5 of FIG. Although not specifically shown, the first filter 4 can be easily replaced by a cartridge type.

As the first filter 4, a thread-wound filter in which a plurality of layers of fibers are wound around a porous cylindrical core material is used. In such a wound filter, filtration is performed by passing a fluid from the outer peripheral surface side to the inner peripheral surface side. As the fiber, a polypropylene non-twisted fiber, a cotton non-twisted fiber, a polyphenylene sulfide non-twisted fiber, or the like is used, and the non-twisted fiber is wound uniformly and firmly. In addition, by providing a density gradient such that the outer side is rough and the inner side becomes denser, the sudden clogging can be prevented, and the life can be prolonged. In addition, as the first filter 4,
For example, a filter that performs filtration by an adsorption action using zeta potential may be used.

Reference numeral 5 denotes a second filter provided on the downstream side of the first filter 4. The second filter 5 has a finer filtration accuracy than the first filter 4, specifically, 0.2. It has a filtration accuracy of about several μm to several μm. The second filter 5 is also of a cartridge type, like the first filter 4, so that it can be easily replaced.

As the second filter 5, a pleated filter is used. That is, as shown in the enlarged cross-sectional view of FIG. 2A, a support filter material 4b made of polypropylene fiber is attached to both sides of a filter material 4a obtained by mixing an inorganic material such as diatomaceous earth with a nonwoven fabric such as polypropylene fiber. In addition, as shown in the perspective sectional view of FIG. In addition, the filtering material 4a
May further include a glass fiber or the like. Further, the inner peripheral surface side and the outer peripheral surface side of the pleated filter are covered with a protector having a large number of windows through which a fluid flows, thereby improving shape retention.

The pleated filter as described above is
Although the structure is simple, it is possible to increase the filtering area by folding the fold. Therefore, by using such a pleated filter, the dampening water filtration device 1
In addition to cost reduction and space saving of the filter 03, it is possible to increase the accuracy of filtration.

Returning to FIG. 1, reference numeral 6 denotes a pressure detector which measures a differential pressure between the upstream and downstream of the first filter 4 and a differential pressure between upstream and downstream of the second filter 5, respectively. A thermometer 7 measures the temperature of the dampening water. Reference numeral 8 denotes a warning lamp, which notifies that the filters 4 and 5 need to be replaced according to the differential pressure between the upstream and downstream of the first and second filters 4 and 5 measured by the pressure detector 6.

In addition to the pump 2 shown in FIG. 1, pumps and valves are appropriately installed where necessary.

Next, the operation of the dampening solution filtration device 103 of the first embodiment will be described. Offset printing press 10
The dampening water used in 1 is guided from each water boat 101b to the suction port 1 of the dampening water filtration device 103 via the dampening water management tank 102.

In the fountain solution filtering device 103, the used fountain solution passes through the first filter 4. The first filter 4 removes relatively coarse impurities such as paper dust and dust.

Next, the dampening solution filtered by the first filter 4 passes through the second filter 5. The second filter 5 removes fine particles such as ink and fine impurities such as bacteria that are not removed by the first filter 4.

By the filtering action of the first and second filters 4 and 5, impurities contained in the dampening solution are substantially removed. The dampening water thus filtered is returned from the discharge port 3 to the dampening water management tank 102. Then, in the dampening solution management tank 102, the concentration, pH, water temperature, etc. of the dampening solution H solution and isopropylene alcohol are adjusted, and the dampening solution is supplied to the offset printing machine 101 again.

When the filtration is repeated and the first filter 4 or the second filter 5 is clogged, a throttling effect is generated, and the pressure difference between the upstream and downstream becomes high. In the present embodiment, the pressure detector 6 measures the differential pressure between the upstream and downstream of the first and second filters 4 and 5, respectively. When the differential pressure between the upstream and downstream of the first filter 4 or the second filter 5 exceeds a predetermined threshold, the warning lamp 8 is turned on to notify the user that the time to replace the filter 4 or the filter 5 has come. Inform. The first and second filters 4, 5
The lighting pattern may be determined according to which one needs to be replaced. Of course, a means other than the lamp 8 such as a buzzer or a display screen may be used as a means for notifying the replacement time. In the present embodiment, the differential pressure between the upstream and downstream of the filters 4 and 5 is detected. For example, the pressure on the upstream side of the first filter 4 or the upstream side of the second filter 5 is detected. By itself, it is possible to detect that clogging has occurred.

According to the first embodiment described above, impurities are removed by the first filter 4 and finer impurities are further removed by the second filter on the downstream side of the first filter 4 so as to be contained in the dampening solution. Impurities can be almost completely removed. Therefore, the dampening solution can be kept clean and circulated, thereby preventing contamination of the piping or the like through which the dampening solution flows and maintaining high quality printing.

Further, since the dampening solution can be reused, there is no need to dispose the dampening solution as industrial waste. In addition, since there is no need to replace the dampening solution, the work of replacing the dampening solution can be omitted, and the offset printing machine can be omitted. Operation efficiency can be improved.

Further, by using two filters such as the first and second filters 4 and 5, the capacity of each filter 4 and 5 can be reduced.
5 can be extended. For example, if one filter is used to remove impurities, a large-capacity filter must be used, and the filtration accuracy must be determined according to the fine impurities. Become.

Moreover, since the pleated filter is used as the second filter 5 as described above, the cost and space of the dampening water filtration device 103 as a whole can be reduced, and high-precision filtration can be performed. .

Here, as the second filter 5, for example, a filter using activated carbon in the form of granules or lump may be used. In this case, if the filter is damaged, the granular or lump of activated carbon flows out. Therefore, it is necessary to arrange an outflow prevention filter downstream of the second filter. On the other hand, in the second filter 5 used in the present embodiment, there is no danger of the filter material flowing out because the filter material is not granular or lump, and there is no need to arrange a filter for preventing the flow out on the downstream side.

FIG. 3 shows the configuration of a dampening solution filtration device according to the second embodiment. The dampening solution filtration device according to the second embodiment is provided with a drainage mechanism for the first and second filters 4 and 5. In the following, the components described in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

In FIG. 3, reference numeral 9 denotes a main pipe connecting the suction port 1 and the discharge port 3, and first and second filters 4, 5 are arranged in the middle of the main pipe.

Reference numeral 10 denotes a first three-way valve disposed on the upstream side of the pump 2. 11 is the downstream side of the pump 2 and the first
Is a second three-way valve arranged upstream of the filter 4 of FIG.
Reference numeral 12 denotes a first auxiliary pipe that connects the first three-way valve 10 to the main pipe 9 at a position downstream of the second filter 5. Reference numeral 13 denotes a second auxiliary pipe that connects the second three-way valve 11 to the main pipe 9 at a position downstream of the first auxiliary pipe 12.

Reference numerals 14 and 15 denote manual valves, which are normally closed, but can be opened to open the first and second filters 4 and 5 to the atmosphere.

Reference numeral 16 denotes a control panel of the filtration device 103, which includes a system operation switch 17, an abnormality alarm release switch 18, a filter drainage switch 19, and a pressure indicator 20. A pressure switch 21 is turned on when the pressure on the upstream side of the first filter 4 becomes equal to or higher than a predetermined pressure. And the main filtration device 103
Although not shown, the switches 17, 18, 19,
Pump 2 and three-way valve 1
An automatic control circuit for controlling 0 and 11 is built in.

Reference numeral 22 denotes a pressure abnormality alarm section, which issues an alarm when the pressure on the upstream side of the first filter 4 becomes equal to or higher than a predetermined pressure. Reference numeral 23 denotes an operating light, which is lit, for example, in green to indicate that the apparatus is operating normally when the apparatus 103 is operating normally. Reference numeral 24 denotes a pressure abnormality light, which is illuminated in red, for example, to indicate that an abnormality has occurred when the pressure on the upstream side of the first filter 4 becomes a predetermined pressure abnormality.

Reference numeral 25 denotes a check valve provided in the main pipe 9 for preventing backflow of the indicated water flowing through the main pipe 9.

Next, the operation of the dampening solution filtering apparatus 103 according to the second embodiment will be described. When the system operation switch 17 is on, the automatic control circuit
To control the three-way valves 10 and 11 of the first and second auxiliary pipes 1
Close the sides 2 and 13. Therefore, the dampening water used in the offset printing machine (not shown) does not flow to these auxiliary pipes 12 and 13 side, and the first damping water flows from the suction port 1 to the first
, The pump 2 and the second three-way valve 11. Then, impurities are removed by the first and second filters 4 and 5, and are returned from the discharge port 3 to the dampening water management tank 102.

Here, when the first filter 4 and the second filter 5 are clogged and the pressure on the upstream side of the first filter 4 exceeds a predetermined pressure, the pressure switch 21 is turned on. In this case, the automatic control circuit issues a stop command to the pump 2. In addition, the abnormal pressure light 24 lights up in red, and the abnormal pressure alarm unit 22 issues an alarm to notify the user that it is time to replace the filters 4 and 5.

The user (operator) can stop the alarm of the pressure abnormality alarm section 22 by turning on the abnormality alarm release switch 18.

When replacing the first and second filters 4 and 5, the filter drain switch 19 is turned on. In this case, the automatic control circuit includes the first and second three-way valves 1
By controlling 0 and 11, the suction port 1 side of the first three-way valve 10 is closed, and the filters 4 and 5 sides of the second three-way valve 11 are closed.
Then, the pump 2 is controlled and restarted.

Further, the operator opens the valves 14 and 15 and opens the first and second filters 4 and 5 to the atmosphere. In addition,
Here, the valves 14 and 15 are manually operated, but these valves 14 and 15 may be automatically opened under the control of the automatic control circuit.

In this state, since the first three-way valve 10 communicates the first auxiliary pipe 12 with the pump 2 and shuts off the suction port 1 side, the moisture remaining in the first and second filters 4 and 5 is reduced. Water is sucked into the pump 2 through the auxiliary pipe 12. At this time, since the valves 14 and 15 are opened as described above, the atmosphere is sucked in the filters 4 and 5 instead of draining the dampening solution.

The dampening solution sucked in as described above is discharged from the pump 2. Here, the second three-way valve 11 is
The auxiliary pipe 13 communicates with the pump 2 and the filters 4, 5
Since the side is shut off, the dampening solution discharged from the pump 2
The liquid is guided to the second auxiliary pipe 13 and discharged to the discharge port 3. Since the check valve 25 is provided, the dampening solution does not flow backward to the filters 4 and 5.

As described above, when draining water, the valve 1
Although both 4 and 15 are opened, the atmosphere can be sucked into the filters 4 and 5 simply by opening the valve 14 on the upstream side. In that sense, it is not necessary to provide the valves 14 and 15 in the filters 4 and 5, respectively, and it is only necessary to provide the valves in the most upstream filter portion (the first filter 4 in FIG. 3). Also, as shown in FIGS. 4A and 4B,
Instead of the valves 14 and 15, the second
An air suction valve 26 may be installed at a position between the three-way valve 11 and the first filter 4. This valve 26 is also normally closed, and is opened manually when draining water or automatically by the control of an automatic control circuit.

According to the second embodiment described above, when replacing the filters 4 and 5, these filters 4, 5
The operator can drain the fountain solution remaining in the
The replacement work can be performed without wetting hands and the like.

Further, as described above, the dampening solution is industrial waste, and the filter in which the dampening solution remains must of course be treated as industrial waste. On the other hand, if the dampening solution can be drained as in the present embodiment, the filter can be treated as general garbage,
Its disposal becomes very simple.

Further, the originally installed pump 2
Is used to drain water, so that increase in cost can be suppressed and dampening water can be drained with a simple configuration.

When the filter draining mechanism described in the second embodiment is applied, the type and number of filters are not limited. That is, a dampening water filtration device provided with a replaceable filter may be provided with a drainage mechanism for draining dampening water remaining in the filter.

[0055]

As described above, according to the present invention, it is possible to circulate dampening water in a clean state by removing impurities almost completely, thereby preventing contamination of piping and the like through which dampening water flows. High quality printing can be maintained.

Further, since the dampening solution can be reused, there is no need to treat it as industrial waste.
Since it is not necessary to replace the dampening solution, it is possible to save labor such as replacement work and improve the operation efficiency of the offset printing press.

Further, by using two filters such as the first and second filters together, the capacity of each filter can be reduced, and the life of each filter can be prolonged.

Further, since a pleated filter is used as the second filter, cost reduction and space saving of the entire dampening solution filtering device can be achieved, and high-precision filtering can be performed. Further, since there is no fear of the outflow of the filter medium, it is not necessary to arrange a filter for preventing outflow on the downstream side.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a dampening solution filtration device 103 according to a first embodiment.

FIG. 2 is a diagram for explaining a pleated filter used as a second filter 5;

FIG. 3 is a diagram illustrating a configuration of a dampening solution filtration device 103 according to a second embodiment.

FIG. 4 shows an example of a valve 26 for sucking air, and FIG.
FIG. 3 is a diagram illustrating an example in which a branch connection pipe is provided in a main pipe 9 and a valve is installed, and FIG. 4B is a view illustrating an example in which a three-way valve is installed in the main pipe 9.

[Explanation of symbols]

 Reference Signs List 101 offset printing machine 102 dampening water management tank 103 dampening water filtration device 101a plate cylinder 101b watercraft 101c roller 1 suction port 2 pump 3 discharge port 4 first filter 5 second filter 6 pressure detector 7 thermometer 8 Warning lamp 9 Main pipe 10 First three-way valve 11 Second three-way valve 12 First auxiliary pipe 13 Second auxiliary pipe 14, 15 Valve 16 Control panel 17 System operation switch 18 Abnormality alarm release switch 19 Drain in filter Switch 20 Pressure indicator 21 Pressure switch 22 Pressure abnormal alarm section 23 Light during operation 24 Pressure abnormal light 25 Check valve 26 Valve

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2C034 AA08 AA42 BB03 BB48 BB59 4D019 AA03 BA01 BA13 BA17 BB03 CA02 CA03 DA10 4D064 AA40 BK01 BK03 BK05

Claims (5)

[Claims] 1. A dampening water filtration device for filtering dampening water used in an offset printing press, comprising: a first filter; and a second filter disposed downstream of the first filter. A pleated filter comprising a filtering material in which an inorganic material is mixed with a non-woven fabric as the second filter, and having a higher filtration accuracy than the first filter. Water filtration device. 2. The dampening solution filtration device according to claim 1, wherein the non-woven fabric of the second filter is a polypropylene fiber. 3. The dampening water filtration device according to claim 1, wherein the inorganic material of the second filter is diatomaceous earth. 4. The dampening water filtration device according to claim 1, wherein the first filter is a thread-wound filter in which non-twisted fibers are wound over several layers. 5. The apparatus according to claim 1, further comprising a pressure detecting means for detecting a pressure at least upstream of said first filter or upstream of said second filter. Fountain solution filtration equipment.