JP2004255354A - Water level monitoring apparatus for coating booth treating water vessel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus having high water level detection precision and capable of stably controlling a water level easily even when an existing booth is used as equipment in the apparatus for automatically controlling the water level of treating water for a coating booth which remarkably affects the collection efficiency. <P>SOLUTION: The high precision water level detection apparatus capable of being simply mounted in a water tank using a back pressure detection system for detecting the back pressure applied on a detection pipe by using a micropressure detector is used. The action in feeding water is controlled by a timer, the service life of a solenoid valve is maintained by preventing chattering in the upper and lower limits and electric wiring in the booth side is dispensed with by using a pneumatic valve as a feed valve in a pipe line to secure safety and to enable the simple attachment to the existing booth. The water level detecting pipe is formed so that the mounting position is easily changeable, and the adjustment of the controlled water levels changing corresponding to the use conditions is simply carried out. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water level of treated water used for mist treatment of a paint booth which collects paint mist of spray paint to purify a working environment and prevent discharge of harmful substances to the outside. The present invention relates to a device that automatically performs management.
[0002]
2. Description of the Related Art Various types of coating booths are used depending on their form and means for collecting paint mist. A washing booth using treated water is often used because of its high collection efficiency. Have been. These water-washing booths have a treatment water tank at the bottom, and the treated water stored there is used for a shower or water curtain for collecting paint mist.
[0003]
Most of the treated water tank is located at the lower part of the mist treatment device. In order to receive the treated water that has captured the paint mist and use the stored treated water for collecting the paint mist, the water level management is important. . In other words, the paint booth circulates a certain amount of water as a water flow for the shower and mist trap in the paint booth.If it is insufficient, it will not be possible to form an appropriate shower or water flow, and if it is too much, it will hinder water flow formation. And the collection efficiency is reduced.
[0004]
In the example shown in FIG. 4, a water tank 1 is provided at a lower part, and an upper water flow plate 2, a washing shower 3 and the like are provided as means for catching paint mist. The treated water stored in the water tank 1 is supplied to the water flow plate 2, the washing shower 3 and the like by a pump, and after catching paint mist, flows into the lower water tank 1 and is stored. A general coating booth filters the sludge formed by mixing and trapping paint particles into the treated water stored in the water tank and sends it to a gutter 4 provided on the upper part of the front water flow plate with a pump to overflow. Thus, a water film is formed by flowing to a water flow plate, and then sent to a water-washing shower 3 in a mist treatment chamber 5 to be sprayed to catch paint mist. In this example, a structure in which the water flow 6 is formed also in front of the water tank is shown.
[0005]
In the example of FIG. 5, an airflow passage S is formed between the water tank 1 and the water surface, and water is sucked by the force of the airflow passing through the gap. It is a coating booth that collects mist by drops, separates water containing mist in the processing chamber, drops it into the water tank, and discharges only clean airflow.It is also a no-pump type seen in Japanese Patent Publication No. 59-10270. It is a painting booth called. In this type of coating booth, the gap between the coating booth and the water surface forming the airflow passage S greatly affects the function, and therefore it is necessary to more strictly control the water level.
[0006]
On the other hand, the treated water evaporates because it is always in contact with the airflow, and at the same time, it becomes easy to evaporate because it becomes a shower or a fine mist for collecting mist, and some fine particles are exhausted with the airflow and the amount of water decreases . Therefore, it is indispensable to always replenish and keep the water level appropriately, for example, within a width of 4 to 10 mm.
[0007]
In general, water level is controlled by a method of replenishing tap water on a regular basis, but it is artificially troublesome, and if the coating machine is automated, the system becomes incomplete. Therefore, there is a need for a device that detects the water level and automatically supplies water.
[0008]
Water level control and automatic replenishment are used in many devices.However, in the case of painting booths, electrical devices are required to be explosion-proof for safety reasons. Automatic formula supply is used. However, there is a problem that the front of the paint booth is stained by the paint mist that scatters, and there is a problem that stable detection is not possible in places where the circulating water flow is severe.In addition, as described above, the treated water incorporating the paint mist Since mist is mixed and many float as sludge on the water surface, it is difficult to install a float for detecting the water level directly in the tank body.As a countermeasure, install an auxiliary tank in which sludge is not mixed and detect the water level. I am replenishing.
[0009]
In this case, there is a problem such as sludge being clogged in the pipeline connecting the auxiliary water tank, and it is difficult to modify the water tank body to install it in the existing painting booth, equipment cost is high, and improvement is easy. There are still problems that cannot be solved.
[0010]
[Problems to be solved by the invention]
In a water-wash type painting booth, water level control of the treatment tank is indispensable to maintain the function of collecting paint mist, and water level control including automatic replenishment is also important from the viewpoint of productivity. The above-mentioned problem can be solved by obtaining an apparatus for accurately detecting the water level of the treated water containing a large amount of sludge and performing an accurate automatic water supply for a decrease in the amount of water.
[0011]
It is another object of the present invention to be able to easily add an existing painting booth to an existing painting booth, improve the collection effect due to insufficient water level management, and relieve the operator from the trouble of supplying water.
It is another object of the present invention to provide an apparatus that can easily adjust and adjust a control range of a water level that changes according to each use condition, in correspondence with various water-washing type painting booths.
[0012]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the present invention includes a water supply pipe for storing treated water as a device for managing a water level of a treated water tank attached to a coating booth that collects paint mist of spray paint by treated water. A water tank, a detection pipe inserted into the water tank to send out the supply air for detection, and a pressure level of the air discharged from the detection pipe is measured by a micro-pressure sensor to detect a liquid surface position, and in response to the detected pressure, A control device that outputs a signal that controls the opening and closing of a control valve provided in the pipe of the water supply pipe.The opening and closing signal of the valve that is output in response to the detected pressure is output with a time difference to open and close the valve. It is configured to control.
[0013]
The valve opening / closing signal to be output is repeatedly turned on and off because the measured liquid level position moves around the boundary near the upper and lower limits. For this purpose, a predetermined time is extended by a timer and a time difference is provided for switching, so that the timer is not frequently performed. The timer is variable so that it can be set to an optimum value according to the changing water level and water supply conditions.
[0014]
The control valve in the water supply pipe is configured to be opened and closed by air output as a control signal by an electromagnetic valve provided in the control device. Further, the position of the opening end of the detection pipe can be changed so that the adjustment of the control water level which changes depending on the use condition can be easily performed.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
The coating booth to which the present invention is applied is a water-washing type coating booth exemplified in FIGS. 4 and 5, which is provided with a treatment water tank, and needs to manage the water level. FIG. 1 shows a simplified configuration, but shows that the water supply for supplying the treated water is supplied from the tap water pipe 11 through the control valve 12 to the water tank 15 from the water supply pipe 13. The detection pipe 16 for detecting the water level is provided at its lower end with an open end 17 for discharging the air sent in for detection, and with the open end 17 inserted into the water, the coating booth wall 18 is fixed by a suitable fixing means. Fixed to. A small amount of small pressure air for detection is sent from the air source 20 to the detection pipe 16 via the air purifier 21, the low pressure reducing valve 22, and the regulating valve 23. Reference numeral 24 denotes a supply air pipe for supply.
[0016]
The detection air is released from the lower end of the detection pipe 16 onto the air bubbles, and maintains the back pressure according to the distance to the water surface. Therefore, the internal pressure of the supply air pipe 24 is detected as the water level from the opening end 17. A branch tube 25 for detection sent to the control device 30 is branched in the middle of the supply air pipe 24, and is connected to a low pressure sensor provided in the control device 30.
[0017]
As shown in FIG. 3, the control device 30 controls the electromagnetic valve 33 by receiving a switching signal from the calculating means 32, which compares the detection result of the fine pressure sensor 31 with a predetermined input value, and receives the open / close signal from the calculating means. A relay 39 that opens and closes is provided. The solenoid valve 33 supplies and stops control air for opening and closing the control valve 12. The control air is sent to the control valve 12 by a control air pipe 34. The supply air pipe 24, the detection air pipe 25, and the control air pipe 34 are all flexible air tubes to facilitate installation.
[0018]
The control panel 35 of the control device 30 has a controller 36 for setting and managing the pressure corresponding to the water level, a lower limit detection timer 37 for detecting the lower limit value of the water level and holding the signal for a certain time after starting the water supply, and a constant after the water supply is started. A water supply abnormality timer 38 for instructing water supply stop by time to prevent overflow, a power supply lamp, a water supply abnormality lamp, a water supply lamp, and the like are provided.
The lower-limit detection timer 37 is connected to the relay 39 via a holding circuit 40, and is configured to take in the operation of the relay 39 in response to an open / close signal from the arithmetic means in accordance with a set time and perform the operation. Further, the water supply abnormality timer 38 starts the water supply by opening the solenoid valve 33 and forcibly activates the relay 39 to close the solenoid valve 33 to stop the water supply when the set time is exceeded, to turn on an alarm or an abnormal lamp. The circuit is configured as follows.
[0019]
As can be understood from the above configuration, the painting booth is equipped with a control valve that operates by air pressure in the middle of the water supply pipe, and a detection pipe that detects the water level is simply attached to the water tank. Equipment can be easily installed without modification. Since the control device for managing the water level can be freely installed at a remote position, there is no need for electrical work, and it can be easily added to existing equipment.
[0020]
On the other hand, the detection pipe 16 inserted into the treated water in the tank of the painting booth is fixed according to the water level to be managed. FIG. 2 shows an example of the mounting method, in which the detection pipe 16 fixed to the mounting plate 26 extends downward. The mounting plate 26 rotates around a support shaft 27 so that the mounting angle can be changed. Therefore, if the mounting plate is rotated and fixed at the position indicated by the dotted line by the fixture 28, the position of the opening end 17 can be changed, and the water level can be finely adjusted.
[0021]
The method of attaching the detection pipe 16 is not limited to this example, and may be any state as long as it is fixed during measurement. The means for changing the position of the opening end 17 may be some means that can be easily changed manually and fixed in a vertically adjustable configuration.
[0022]
【Example】
As an embodiment of the present invention, as shown in FIG. 2, the detection pipe 16 attached to the painting booth has the opening end 17 located 100 mm below the lower limit position L of the water surface to be managed, is fixed to the wall surface 18, and has the upper water level limit. H is set at 8 mm from the lower limit position L. These setting values can be stored in the controller 36 as initial settings of the control device 32. If the depth is changed due to the installation position in the water tank 1 or the influence of the sludge, or if the upper and lower limits of the water level management width are changed by the coating booth, the controller 36 of the control device 30 sets the set value. May be changed and stored in the arithmetic means.
[0023]
During operation, when air is sent from the detection air source 20 to the detection pipe 16 through the fine pressure reducing valve 22, the air is discharged from the opening end 17 and becomes air bubbles B and comes out on the water surface. At this time, the amount of air supplied by the regulating valve 23 is adjusted so that one or two bubbles are formed in one second.
[0024]
The supply pressure is supplied at a pressure higher than the maximum pressure to be detected, is discharged from the opening end 16 of the detection pipe, becomes a pressure maintained at the back pressure corresponding to the water level, and is supplied to the micro pressure sensor 31 of the control device 30. Acts, detects the pressure and outputs a signal in comparison with a set value. That is, if the water level is 100 mm, a back pressure of 1 kPa is applied. Therefore, by continuously supplying a slightly higher pressure, the pressure in the supply air pipe 24 is increased by the air discharged from the open end 17. , And the water level can be detected by the micro-pressure sensor 31.
[0025]
In the example of FIG. 2, when the water level becomes 100 mm or less, it detects that it is the lower limit value, and outputs a signal for opening the valve. The output signal actuates the relay 39, sends an actuation signal to the solenoid valve 33 to actuate it, sends working air to the control valve 12, opens the control valve 12 provided in the middle of the water supply pipe, and starts water supply. .
[0026]
At this time, if there is a drastic fluctuation in the measured water level, the water level is temporarily detected as a value of 100 mm or more, and the signal to the relay 39 repeatedly turns on and off in a short time, causing so-called chattering. The relay is significantly damaged. In the present invention, when the operation of the relay is repeated, a holding circuit for a fixed time is provided, and even if a repetitive signal from the arithmetic means comes in the meantime, the state is maintained without being taken in. The fixed time can be selected by the timer 37 so that it can be changed and set according to the installation conditions. Therefore, operation stability and long-term use can be achieved without impairing the durability of the relay 39 and the solenoid valve 33.
[0027]
In the present invention, after the valve is opened, the state is maintained by a timer for a fixed time, and a time difference is provided for the next closing operation, so that even if there is a sharp change in the detection value due to the fluctuation of the water level, the water supply is maintained for a while. Therefore, so-called chattering is prevented without being affected by a sharp fluctuation or wave of the water level in a short time. In this example, it is set to 10 to 30 seconds. However, depending on the installation position of the detection pipe, it differs between a place where the water level fluctuates greatly and a place where the water level fluctuates, and avoids the limit value by setting a time during which water supply exceeding the water level fluctuation width is possible. be able to. In addition, if it is held for a certain period of time, frequent operations are suppressed, and operation stability can be achieved.
[0028]
In this regard, the present invention enables adjustment of the time difference, and allows optimal setting depending on the type of the installation booth to be installed, the installation location, etc., and has high versatility, including installation in an existing booth. Water level management becomes possible. The holding time is not limited to the above example, and it is generally determined that there is no problem with frequent operation if the operation is performed at intervals of 10 to 30 seconds.
[0029]
Further, when the water supply is performed and the water level reaches 108 mm, the water supply is stopped. Even if the water supply is not stopped due to some abnormality, a timer for stopping the water supply after a certain period of time is provided to avoid a problem such as overflow. This may be set in advance by checking the size of the water tank and the water supply conditions.
[0030]
The detection pipe 17 may be attached at any place as long as the water surface of the water tank 15 can be measured. However, it is needless to say that a place where the water surface is stable is desirable. In addition, it is preferable to avoid a place where sludge taken into the water easily accumulates, and to set a place that is not affected by the sludge, or a position that does not hinder handling during cleaning or adjustment. If there is no stable part as it is, measures such as relaxing the wave with a partition plate may be taken.
[0031]
As described above, the mounting depth of the detection pipe 16 and the management width of the upper and lower limits can be adjusted by the control device. However, according to the embodiment of the present invention, the depth is temporarily changed depending on the actual operation conditions, water supply conditions, and the like. In the case of the adjustment or fine adjustment, the position of the opening end 17 of the detection pipe 16 can be changed, so that it is possible to easily cope with the change without changing the set value.
[0032]
【The invention's effect】
As described above, the present invention uses the back pressure type liquid level detection to control the water level of the treated water in the coating booth, so that the detection of the circulating water is less likely to be affected by sludge accumulated on the water surface. Therefore, it is possible to obtain a water level management device in which the installation location is not limited even when the fluctuation or the wave easily occurs. In particular, by stabilizing the operation based on the detection result with a time lag, there is always flow like a painting booth, and stable detection and water supply management can be performed even for water levels and waves that fluctuate in a short time. Was.
[0033]
In addition, there is no restriction on the installation location, and the detection pipe and control device that can be freely installed can control the opening and closing of the control valve by pneumatic operation provided in the water supply pipe. It is not necessary to add an auxiliary tank as described above or to perform wiring work on site, and it is possible to add an automatic water level management device at low cost. This not only reduces the burden on workers, but also improves the original productivity, and also keeps the collection efficiency of the paint booth always at optimal conditions, thus reducing the emission of harmful substances into the atmosphere. It is possible to spread devices that can be suppressed and contribute to the prevention of environmental pollution.
[Brief description of the drawings]
FIG. 1 is a configuration diagram illustrating an example of an embodiment of the present invention.
FIGS. 2A and 2B show an embodiment of a mounting state of a detection pipe according to the present invention, wherein FIG. 2A is a sectional view and FIG. 2B is a side view of FIG.
FIG. 3 is an explanatory diagram showing a main configuration of a control device of the present invention.
FIG. 4 is a configuration diagram showing an example of a water-washing type painting booth applied to the present invention.
FIG. 5 is a schematic diagram showing a processing chamber of a no-pump type painting booth.
[Explanation of symbols]
Reference Signs List 12 control valve 15 water tank 16 detection pipe 17 detection pipe 21 filter 22 pressure reducing valve 23 throttle valve 24 supply air pipe solenoid valve 26 mounting plate 30 control device 31 low pressure sensor 32 calculation means 33 solenoid valve 34 control air pipe 35 control board 36 controller 37 Lower limit detection timer 39 Relay 40 Holding circuit

Claims (5)

An apparatus for controlling the water level of a treatment water tank attached to a coating booth that collects paint mist of spray paint by treated water, and stores a circulating treated water and a water tank provided with a water supply pipe, and returns to the water tank. A detection pipe that is inserted into the stable water that has been stored and sends out supply air for detecting the water level, and detects the air pressure discharged from the detection pipe, and in response to the detection pressure, A water level management device for a coating booth treatment tank, comprising a control device for outputting a signal for controlling the opening and closing of a control valve provided. 2. The water level management device for a treated water tank according to claim 1, wherein a time difference by a holding circuit is provided to the open / close signal output in response to the detected pressure, and the open / close signal of the control valve is output. The water level management device for a treated water tank according to claim 1, wherein a timer that can arbitrarily set a time difference provided in the control valve opening / closing signal is used. The water level management device for a treated water tank according to claim 1, wherein the control valve in the water supply pipe is a pneumatic valve that is opened and closed by air from the control device. The water level management device for a treated water tank according to claim 1, wherein an opening end position of the detection pipe is movable with respect to a mounting position to the painting booth.

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