JP2986834B2 - Clean workbench - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a cleaning workbench for purifying air in a work space, and is particularly suitable for preventing harmful substances and microorganisms from leaking outside. About.

[Prior Art] An example of a configuration of a conventional cleaning work table of this type will be described with reference to FIG. In FIG. 1, air discharged from a blower 1 is sent to a work space A by being purified by passing through an air supply filter 2, and the air is discharged from an exhaust opening 3 provided in the work space A to a duct. B, the air is sucked into the blower 1 installed downstream of the duct B, and a part of the air is exhausted to the outside by passing through the resistance plate 4, the exhaust filter 5, and the building duct C. I have.

The working space A includes an air supply opening 6 provided with an air supply filter 2 at the upper part and a resistance plate 9 arranged downstream thereof, and the exhaust opening part 3 formed to exhaust the space flowing into the lower part. In addition, a door 7 is provided on one side of the door 7 so as to be openable and closable. When air is sucked into the duct B from the exhaust opening 3, external air is also sucked from the opening of the door 7.

The exhaust opening 3 is connected to a duct B, and the blower 1 is attached to the downstream side of the duct B, and a detector 10 for detecting an abnormal state of air is provided. The detector 10 comprises a differential pressure gauge, one of which has a pressure detection hole.
10b is arranged on the inlet side of the exhaust filter 5,
The other pressure detection hole 10a is arranged on the air inlet side of the resistance plate 4, and the pressure detection holes 10a and 10b detect the pressure of the air passing therethrough and measure the differential pressure. . When the pressure difference falls below the limit, it can be understood that the filter 2 is clogged. Tenth
In the drawing, reference numeral 11 denotes an exhaust blower provided in a building duct.

It should be noted that a related apparatus of this type is, for example, Japanese Utility Model Publication No. 46-17261.

[Problems to be Solved by the Invention] By the way, the above-described conventional cleaning work table has a problem in which consideration is not given to handling harmful substances and microorganisms.

That is, in the prior art, since one of the detectors 10a and the other 10b is disposed on the upstream side and the downstream side with the resistance plate 4 interposed therebetween, when the hazardous substance is handled in the work space A, the work space A Is contaminated with the harmful substance, and when the contaminated air passes through the duct B, not only one of the pressure detectors 10a of the detector 10 but also the other pressure detector 10b is contaminated. During inspection, there was a problem that workers touched harmful substances and caused danger.

In addition, the clean workbench is, for example, "Recombinant DNA Experiment Guideline"
When used as a safety cabinet as shown in the above, airtightness is required, so the main body of the detector 10 and the pressure detector
It is necessary to consider the air tightness that reaches the piping system of 10a and 10b. However, if the detector 10 is not installed in advance and it is added and modified, in addition to the problems described above, the required airtightness may be satisfied due to the used parts and inadequate mounting. There is a problem that is difficult to do.

In view of the above circumstances, an object of the present invention is to provide a cleaning workbench that can prevent a detector from being contaminated with harmful substances, and another object is to provide a cleaning workbench that is not installed in advance. Another object of the present invention is to provide a clean workbench that can maintain air tightness even if a detector is attached to the work space. To provide a clean workbench that can be obtained.

[Means for Solving the Problems] To achieve the above object, in the first invention of the present invention,
Pressure generating means provided downstream of the exhaust filter, measuring means for measuring pressure before and after the pressure generating means, and detecting means for detecting an abnormal state of the device based on the output of the measuring means It has features.

Further, in the second invention of the present invention, there is provided a blower for sucking external air and sending it to the working space from the air supply opening. In a third aspect of the present invention, the pressure generating means and the measuring means are mounted in a chamber connected to a downstream side of an exhaust filter.

[Operation] As described above, according to the present invention, as described above, the pressure generating means provided on the downstream side of the exhaust filter, the measuring means for measuring the pressure before and after the pressure generating means, and the abnormal state of the apparatus based on the output of the measuring means Therefore, the air that has flowed out of the exhaust opening of the working space passes through the exhaust filter, is purified, and then passes through the pressure generating means and the measuring means.

Therefore, even if the material handled in the work space is a harmful substance and is contaminated with the harmful substance, the polluted air can be reliably purified by the exhaust filter, so that the measuring means and the detecting means are not contaminated. There is no danger even if the operator touches the measuring means and detecting means during maintenance and inspection.

In addition, since there is a blower that sucks in external air and sends it into the work space from the air supply opening, when gas or bacteria is handled in the work space, the air in the work space is discharged to the outside. And it will not circulate.
Therefore, compared to the type that circulates the air in the work space, it is possible to prevent the gas concentration or the bacteria from increasing in the work space, and in addition to being able to avoid the danger, the gas and It is even more beneficial for those dealing with bacteria.

Further, since the pressure generating means and the measuring means are mounted in a chamber connected to the downstream side of the exhaust filter, the chamber having the pressure generating means and the measuring means is made into one unit, which is called a pressure generating means and a measuring means. If it is added later, the airtightness of the measuring means in the chamber can be reliably maintained, and the air flowing through the working space does not leak to the outside.

Embodiment An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is an explanatory sectional view showing a first embodiment of a cleaning work table of the present invention, FIG. 2 is an explanatory view showing a relationship between air pressure and opening and closing of a differential pressure switch of a detector, and FIG. It is a flowchart which shows the control content of the normal starting means of a differential pressure switch in the detector of a work bench.

The cleaning worktable includes a work space A and an exhaust filter 5.

More specifically, the work space A has an air supply opening 6 into which the air purified by the air supply filter 2 flows. Downstream of the air supply opening 6, a resistance plate 9 for rectifying the air flowing into the work space A is attached. The work space A has an exhaust opening 3 formed for exhausting the air flowing into the lower part, and a door 7 attached to one side thereof so as to be openable and closable. When the air is sucked into the duct B from the outside 3, the outside air is also sucked together from the opening of the door 7. In addition, the exhaust opening 3 is connected to the first duct B1, and the suction section of the blower 1 is connected to the downstream side of the first duct B1, so that the blower 1 sucks the air passing through the first duct B1. I have.

The exhaust filter 5 is connected to the downstream side of the second duct B2 provided on the discharge side of the blower 1, and is arranged at a position facing the air supply filter 2 in the second duct B2. Therefore, the air sucked from the first duct B1 by the blower 1 is sent to the air supply filter 2 side through the second duct B2, and is also sent to the exhaust filter 5.

In the embodiment, a detector 10 as a measuring means is disposed downstream of the exhaust filter 5. The detector 10 is constituted by a differential pressure gauge, and has two pressure detecting holes 10a and 10b connected thereto. One pressure detection hole 10a is disposed on the upstream side of the resistance plate 121 in the chamber 12 provided on the downstream side of the exhaust filter 5, and the other pressure detection hole 10b is disposed on the discharge side of the resistance plate 121. The pressure detection holes 10a and 10b take in air passing through the respective positions to detect a differential pressure of the air.

At this time, the tip of the pressure detection hole 10a is arranged in the connecting portion 17 so as to face the flow of the air that has passed through the exhaust filter 5, and detects the static pressure and the dynamic pressure to increase the differential pressure detection accuracy. Have to be able to.

The chamber 12 is connected between the exhaust filter 5 and the building duct C, and includes therein the resistance plate 121 provided on the upstream side and the exhaust blower 11 provided on the downstream side. The air passing through 5 is rectified through the resistance plate 121, is sucked into the blower 11, and is discharged outside through the building duct C.

The detector 10 is a differential pressure switch as a detecting means.
Has 100. The differential pressure switch 100 is operated when the differential pressure of air is out of a desired range as a result of the detection by the detector 10, so that the controller 13 sounds the alarm 14 and displays NG on a display (not shown). ing. Although a display is not shown in this example, if the air volume of the workbench is within a desired range, OK is displayed, and if out of range, NG is displayed.

By the way, in general, when the differential pressure switch reaches a certain pressure Pu as shown in FIG. 2, the closed one rises and opens to change from 0 to 1, and a different pressure Pd
Is reached, the falling and closing changes from 1 to 0, and therefore the values of Pu and Pd need to be different in order to stably operate the differential pressure switch.

However, for example, when the air supply filter 2 is clogged when the cleaning work table is started, if the value detected by the detector 10 is smaller than the pressure Pu and larger than the pressure Pd,
If this detection value is taken as it is, the differential pressure switch 100 will not operate, and will not operate. At that time, if the pressure Pd is set to the lower limit of the predetermined air volume, the differential pressure switch 100 does not rise, so that the controller 13 sounds the alarm 14 and displays NG, and the normal air volume is displayed. However, the differential pressure switch does not operate.

Therefore, in the embodiment, when the cleaning work table is started (when the blower 11 is operated), when the air volume of the air flowing through the work table reaches the lower limit value of the predetermined air volume, the differential pressure switch 100 normally starts. There is a means for starting the differential pressure switch in order to perform the raising operation. In this means, one pressure detection hole 10a of the detector 10 is connected to the differential pressure switch 100, and the pressure detection hole 101 is further connected to the differential pressure switch 100. The pressure detection hole 101 is arranged on the discharge side of the blower 11 in the chamber 12 so as to detect the air pressure discharged from the blower 11. Still pressure detection hole 10
An electromagnetic valve 102 for opening and closing this pipe is mounted at a position in the pipe between the pressure switch 1 and the differential pressure switch 100.
02 is opened and closed by a command from the controller 13.

The above-mentioned means, when starting up the cleaning work table, the controller
Excites the electromagnet 103 of the solenoid valve 102 according to the instruction from 13,
The solenoid valve 102 is kept open, and during that time, the differential pressure switch 100 rises with the differential pressure of air between the one pressure detection hole 10a and the pressure detection hole 101, whereby if the lower limit of the predetermined air volume is reached, it is ensured that Startup operation is performed. In addition,
When the differential pressure switch starts up, the solenoid valve 102 is closed by a command from the controller 13.

As described above, in the cleaning workbench of the embodiment, since the detector 10 is disposed on the downstream side of the exhaust filter 5, the air discharged from the blower 1 passes through the air supply filter 2 and is purified. While being supplied to the working space A, it is purified after passing through the exhaust filter 5 and then sent to the detector 10 side.

Therefore, even if a substance handled in the work space A is a harmful substance and is contaminated with the harmful substance, the contaminated air can be surely purified by the exhaust filter 5, so that both the pressure detection ports 10a and 10b of the detector 10 Contamination is eliminated, and even if the operator touches the pressure detectors 10a and 10b during maintenance and inspection, danger can be reliably prevented.

Further, since the detector 10 is mounted in the chamber 12 connected to the downstream side of the exhaust filter 5, the chamber 12 having the detector 10 is formed as one unit, and this is later replaced with a unit without the detector 10. If added, the air density around the pressure detection holes 10a and 10b in the chamber 5 can be reliably maintained, and the air flowing through the work space A does not leak to the outside.

Further, when the cleaning worktable is started (when the blower 11 is operated), when the air volume of the air flowing through the worktable reaches the lower limit value of the predetermined airflow, the differential pressure switch 100 starts up normally. Therefore, the differential pressure switch 100 can be reliably operated when the workbench is started up. As a result, the controller 13
Can be prevented from being displayed on the alarm device 13 as NG.

Incidentally, a control example of the controller 13 will be described with reference to FIG.

In FIG. 3, when the cleaning workbench is operated, the controller 13 turns on the electromagnet 103 of the solenoid valve 102 to turn on the solenoid valve 102.
Open (301), sound alarm 14 and display NG (302)
At the same time, the OK display indicating the normal state is turned off (303).

Then, it is determined whether or not the differential pressure switch 100 has been turned on (304). As a result of the determination, when the differential pressure switch 100 is turned on, the electromagnet 103 is turned off (305), the NG display of the alarm 14 is turned off (306), and the OK display is made (307). Determine whether the switch is on (30
8). If the differential pressure switch 100 is not turned on as a result of the determination in 304, the process of 311 described later is executed.

If the result of determination in 308 is that the differential pressure switch 100 is on, the processing from 305 is repeated, while if the differential pressure switch 100 is off, the OK display is turned off (309) and the NG display is turned on. (310).

Thereafter, it is determined whether or not the air volume of the worktable can be increased (311). If it is possible to increase the air volume, the air volume of the blower 11 is increased (312).
The subsequent processing is repeatedly executed. On the other hand, if it is not necessary to increase the air flow, the air flow is kept as it is.
Turn off (313) and stop the platform operation.

Therefore, the controller 13 controls the solenoid valve 10 as described above.
By controlling the opening / closing operation of the alarm device 14 and the blower 11 and the blower 11, it is possible to accurately display the NG and OK of the alarm device 14.

 FIG. 4 shows a second embodiment of the present invention.

In this embodiment, since the flow of air is basically the same as in the first embodiment, different points will be described.

That is, in this case, the downstream side of the exhaust filter 5 is connected to the exhaust blower 11 via the chamber 12, the building duct C and the like. The chamber 12 is provided between the exhaust filter 5 and the building duct C, and the first and second resistance plates 1 are provided on the downstream side.
It has a connecting portion 15 to which 6, 17 are attached.

The detector 10 arranged on the downstream side of the exhaust filter 5 is formed by integrating a differential pressure gauge and a differential pressure switch, and one of the pressure detection ports 10 a The other pressure detection port 10b is arranged on the upstream side of the first resistance plate 16 and on the downstream side of the first resistance plate 16, respectively.

Further, the detector 10 is connected with an indicator 18 for notifying whether or not the differential pressure state detected thereby is abnormal. When the value detected by the detector 10 falls below an appropriate range and rises, the indicator 18 lights an NG lamp indicating an abnormal state, and notifies the normal state only when the value is within an appropriate range. Lamps are turned on,
In addition, in the case of an abnormal state, the alarm 14 connected to the alarm emits an alarm so that a nearby worker can be reliably informed. A controller 13 is connected to the detector 10, and controls the on / off of the blower 1 and the exhaust blower 11 and the amount of the blown air based on the detection value of the detector 10.

Further, the detector 10 detects a differential pressure of the air and a sensor 10c for detecting a gas concentration, dust, and the like, respectively.
When the sensor 10c detects gas concentration, dust, or the like, the detector 10 displays a display in accordance with the gas concentration or dust amount.
14 can be displayed as NG or OK.
Therefore, the detector 10 of this embodiment is also configured to display the fact on the display 14 based on the detection of the sensor 10c.

Further, a gate valve 19 for opening and closing the passage is provided in the connecting portion 15 of the chamber 12. The gate valve 19 is movable within the connecting portion 15 to a position upstream of the pressure detection hole 10a so as to close the passage of the connecting portion 15 for sterilization or the like due to contamination of the working space A with bacteria or the like. Installed.

According to this embodiment, since the detector 10 is disposed downstream of the exhaust filter 5 and the detector 10 is disposed at the connecting portion 15 of the chamber 12, the same operation and effect as in the first embodiment are obtained. Can be obtained.

In addition, in sterilization, the chamber 12 is
The work space A can be shut off from the outside only by closing the passage of the connecting portion 15 and occupying the door 7, so that the pre-operation for sterilization can be easily performed. At the time of sterilization, sterilization is performed by putting a disinfectant into the space including the working space A. At this time, if the gate valve 19 is movably mounted, the operation of the gate valve 19 can be operated extremely easily. . Moreover, since the gas concentration and dust are detected by the sensor 10c, it is effective even when the gas concentration and dust are increased due to a long working time.

 FIG. 5 shows a third embodiment of the present invention.

In this case, the blower 1 and the exhaust filter 5 are respectively installed downstream of the duct B, and the air in the duct B is sucked into the blower 1 and passes through the exhaust filter 5. . Therefore, basically, the same operation and effect as those of the above-described embodiment can be obtained, and the detailed description is omitted here.

 FIG. 6 shows a fourth embodiment of the present invention.

In this case, the blower 1 is applied to a device in which the outside air is sucked.

That is, in this embodiment, the second duct B2 is formed at the upper part of the workbench body, the suction port 31 communicating with the outside is formed at the upper part of the duct B2, and the blower 1 is inserted into the duct B2.
Is arranged so that the blower 1 sucks outside air from the suction port 31 and sends it to the work space A. The suction port 31 is provided with a filter for removing dust and the like mixed in the external air.

Further, the downstream side of the first duct B1 is connected only to the exhaust filter 5, and the air exhausted from the work space A is discharged to the duct B1,
The air is exhausted to the outside via the exhaust filter 5 and the like.

According to this embodiment, since the blower 1 takes in air from the outside and supplies it to the work space A, when gas or bacteria is handled in the work space A, the air in the work space A The air is discharged to the outside by the blower 11 through one duct B1, and does not circulate. Therefore, as compared with the type in which the air in the work space A is circulated as in the above-described embodiment, it is possible to prevent the gas concentration or the bacteria from increasing in the work space A, thereby avoiding the risk. In addition to being able to do it, it is even more beneficial for those dealing with gases and bacteria.

 7 and 8 show a fifth embodiment.

This case is a modification of the second to fourth embodiments, in which the sterilization operation can be automated.

That is, rollers 20, 20 'for moving the gate valve 19 attached to the chamber 12 are provided, and the rollers 20, 20' are provided.
An operation unit 21 for rotating and driving the 20 'is provided, and a gas generator 22 for injecting sterilizing gas into the work space A by operating the operation unit 21 is provided. Roller 2
As shown in FIG. 8, the reference numerals 0 and 20 'are arranged so as to sandwich the gate valve 19 therebetween, and when rotated by driving means (not shown), the gate valve 19 moves to connect the connecting portion of the chamber 12.
The inside of the packing 23 provided on the 15 is partitioned. For this reason, the detector 10 of this embodiment also has a function of driving the gate valve 19 via the driving means by operating the operation unit 21.

Therefore, when the display 18 and the alarm 14 notify the abnormality based on the detector 10, the operator isolates the subject handled in the work space A, closes the door 7, and then operates the operation unit 20. When the switch is pressed, the rollers 20, 20 'rotate, and the gate valve 2
0 moves to block the passage of the connecting portion 15, and at the time of the blocking, the sterilizing gas is injected from the gas generator 22 into the work space A.

As described above, in the case of an abnormality, the sterilization operation can be automated by the operation, so that the sterilization operation can be performed more smoothly than in the above-described embodiment.

 FIG. 9 shows another embodiment of the present invention.

In the above-described embodiment, when the sterilizing gas in the working space A is discharged to the outside by the exhaust blower 11 after the sterilization, the sterilizing gas may enter the detector 10 and have a bad influence.

In this embodiment, even if sterile gas enters the detector 10,
The gas is reliably removed by the gas removing means. That is, as the removing means, the detector 10 and the pressure detecting hole
For example, a solenoid valve 24 formed of a three-way valve is provided in a passage between the solenoid valve 10a and the solenoid valve 25 is similarly provided in a passage between the pressure detection hole 10b and the detector 10, and these solenoid valves 25 and 24 are provided. They are connected together by a bypass pipe 31. In addition, a solenoid valve 26 is connected to a connection portion provided between the solenoid valve 25 and the pressure detection hole 10a, and a blower 28 is connected to the solenoid valve 26 via a filter 27. An analyzer 29 for analyzing the amount of dust and the like is connected. Reference numeral 30 denotes a control unit having substantially the same functions as those of the controller of the above-described embodiment.

Then, when the blower 11 for exhaust discharges the sterilizing gas in the working space A to the outside after the sterilization, if the electromagnetic valves 24 to 26 are closed by the analyzer 29, the pressure detecting holes 10a and 10b are inserted into the inside. Even if a sterilizing gas or the like enters, the sterilizing gas or the like is prevented from entering the differential pressure gauge, the differential pressure switch 100, and the analyzer 29 on the main body side of the detector 10.

When the sterilizing gas is discharged to the outside, the solenoid valves 24 to 26 are opened, the blower 28 is driven, and the clean air that has passed through the filter 27 is sent in, so that the pressure detection holes 10a and 10b and the solenoid valves 2
The residual gas that has entered the pipeline between 4 and 26 is
The air is exhausted to the connecting portion 15 through a and 10b.

Therefore, according to this embodiment, even if the sterilizing gas enters the detector 10 when it is exhausted by the blower 11, it can be reliably taken out, so that not only the detector 10 but also the analyzer 29 can be removed by the sterilizing gas. It is extremely effective when an apparatus which is not adversely affected and which is easily affected by gas or the like is used.

[Effects of the Invention] As described above, according to the first aspect of the present invention, even if what is handled in the work space is a harmful substance and is contaminated by this,
Since the contaminated air can be reliably purified by the exhaust filter, the measuring means and the detecting means are not contaminated, and even if the worker touches the measuring means and the detecting means during maintenance and inspection, there is a danger. There is no effect.

According to the second aspect, since the air in the working space is discharged to the outside and does not circulate, the gas or bacteria is handled in the working space as compared with the type in which the air in the working space is circulated. In this case, it is possible to prevent an increase in gas concentration or bacteria in the working space, thereby avoiding the danger, and further, it is more advantageous for those handling gas and bacteria.

According to the third aspect, since the pressure generating means and the measuring means are mounted in the chamber connected to the downstream side of the exhaust filter, the chamber having the pressure generating means and the measuring means is made into one unit, If it is later added to the one without the generating means and the measuring means, the airtightness of the measuring means in the chamber can be reliably maintained, and the air flowing through the working space does not leak to the outside.

According to the fourth aspect, the work space can be shut off from the outside by closing the gate valve, so that the operation for sterilization can be simplified. And Claim 5
According to the method, since the sterilizing gas is injected into the working space by the gas generator, the sterilizing operation can be automated.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory sectional view showing a first embodiment of a cleaning work table according to the present invention, and FIG. 2 is an explanatory view showing a relationship between air pressure and opening and closing of a differential pressure switch of a detector. FIG. 3 is a flowchart showing the control contents of the normal startup means of the differential pressure switch in the detector of the cleaning work table. FIG. 4 is a sectional view for explanation showing the second embodiment of the present invention. FIG. 6 is a sectional view for explanation showing a third embodiment of the present invention, FIG. 6 is a sectional view for explanation showing a fourth embodiment of the present invention, and FIG. 7 is a fifth embodiment of the present invention. FIG. 8 is a perspective view of a main part showing a gate valve and a chamber, FIG. 9 is a piping diagram of a main part showing a means for removing gas that has entered a pressure detector, and FIG. FIG. 4 is an explanatory cross-sectional view illustrating a configuration example of the cleaning worktable of FIG. 1 ... blower, 2 ... air supply filter, A ... work space,
B, B1, B2 ... duct, 3 ... exhaust opening of working space, 5
... exhaust filter, 6 ... air supply opening in the working space, 10 ...
… Detector, 10a …… Pressure detection hole, 10b …… Pressure detection hole, 12
... chamber, 13 ... controller, 19 ... gate valve, 22 ... gas generator.

Claims (5)

(57) [Claims] A work space provided with an air supply opening and an air discharge opening, and an exhaust filter provided in communication with the exhaust opening of the work space to exhaust air in the work space. In a cleaning workbench that exhausts air from the opening through the exhaust filter to the outside of the work, a pressure generating means provided downstream of the exhaust filter, a measuring means for measuring pressures before and after the pressure generating means, A detection means for detecting an abnormal state of the apparatus based on an output of the means. 2. A clean workbench according to claim 1, further comprising a blower for sucking external air and sending the air into a work space from an air supply opening. 3. A cleaning work table according to claim 1, wherein said pressure generating means and said measuring means are mounted in a chamber connected to a downstream side of an exhaust filter. 4. The cleaning work table according to claim 3, wherein a gate valve for shutting off a passage of the chamber is attached to the chamber at a position upstream of the pressure generating means and the measuring means. 5. The cleaning worktable according to claim 4, further comprising a gas generator for injecting a sterilizing gas into a work space when the gate valve closes a passage of the chamber.