JP4558152B2 - Room pressure control method in advanced clean facility - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a room pressure control method in an advanced clean facility, and in particular, the air supply amount maintains a predetermined amount difference with respect to the exhaust amount, thereby stabilizing the room pressure of the facility, and the air flow between the facilities. The present invention relates to a room pressure control method in an advanced clean facility that maintains a room pressure in one direction.
[0002]
[Prior art]
In production facilities that require a high degree of cleanliness and industrial facilities that handle pollutants, cross-contamination of air generated between the room and other rooms or the outside becomes a problem. In order to avoid this problem, the chamber pressure control is performed so that the air flow between the chambers is in one direction.
[0003]
In buildings such as pharmaceutical manufacturing factories, food factories, and semiconductor manufacturing factories, which are one of these production facilities, it is necessary to prevent intrusion of dust and germs from the outside. It is controlled so as to be positive pressure to the chamber.
[0004]
On the other hand, in special chemical factories and biohazard countermeasure facilities (hereinafter referred to as BH facilities), room air must be prevented from leaking to the outside, so the room pressure is kept negative with respect to the outside air. The room pressure is controlled as follows.
[0005]
Conventional chamber pressure control is performed by the control circuit shown in FIG. 4, and at the time of starting and stopping the fan in the above process, in order to maintain the required chamber pressure between the chamber and the other chamber, The operation control was adopted.
[0006]
The BH facility 20 is composed of a breeding room 21 and an anterior room 22, which are connected by a door 23. The breeding room 21 is provided with a safety cabinet 24 and the like so that a predetermined work can be performed.
[0007]
The BH facility 20 is supplied with conditioned air and exhausted from the room by an air supply fan 25 and an exhaust fan 26 in the air conditioner. A constant air volume device 27 and a high performance filter 28 are arranged between the air supply fan 25 and each chamber, respectively. Between each chamber and the exhaust fan 26, a high performance filter 28 and a variable filter 28 are arranged. Air volume devices 29 are arranged in each. A high-performance filter 28 is also disposed between the safety cabinet 24 and the exhaust fan 26 so that contaminated air is not discharged outside.
[0008]
The breeding room 21 and the front room 22 keep the air supply air volume constant by the constant air volume devices 27, and also by the differential pressure signal from the differential pressure gauge 30 arranged between the breeding room 21 and the front room 22. The flow rate of the air volume change device 29 is adjusted mutually so that the breeding room 21 always maintains a negative pressure with respect to the front room 22. As a result, the differential pressure of, for example, 30 (Pa) is controlled between the breeding room 21 and the front room 22 so that an air flow from the front room 22 to the breeding room 21 is formed. ing.
[0009]
However, at the BH facility, it is necessary to stop the air conditioning when the work content is changed, etc. After the change, the fan is restarted as soon as possible so that the air in the room does not leak outside. On the other hand, it was necessary to control the room pressure to return to the negative pressure.
[0010]
For this reason, also in the above control circuit, by adopting the inverter 31 for the air supply / exhaust fans 25, 26, the rated rotational speed of the air supply / exhaust fan can be changed and the rise time from the start to the rated rotation is also increased. By controlling the startup characteristics of the air supply / exhaust fans at the time of startup, the normal operating state at the same time as the restart of the BH facility 20 is directed.
[0011]
These controls are performed by adjusting the setting of the inverter 31 in the control panel 32. FIG. 5 shows an example of a conventional control form, and FIG. 6 shows the front chamber controlled thereby. It is the transition state of absolute pressure at.
[0012]
The adjustment and control in the control panel 32 are performed according to the flowchart of FIG. 5 and are developed in the following order from the start of adjustment to the continuation of steady operation.
[0013]
(1) Setting the rated speed of the supply / exhaust fan. The rated rotational speed (Rs) of the air supply fan 25 and the rated rotational speed (Re) of the exhaust fan 26 are set to Re> Rs.
[0014]
(2) Setting of the starting time until the rated speed of the supply / exhaust fan is reached. The start time (Ts) of the air supply fan 25 and the start time (Te) of the exhaust fan 26 are set to Ts> Te.
[0015]
(3) Simultaneous startup when the air supply / exhaust fan is turned on. Since the speed of increase of the rotational speed of the supply / exhaust fan is different, the negative pressure gradually increases in the room.
[0016]
(4) Rated operation after Te time of the exhaust fan 26. The negative pressure after Te time becomes the largest .
[0017]
(5) Rated operation after Ts time of the air supply fan 25. It converges to the desired negative pressure due to the difference in the rotation speed of the supply and exhaust fans. (6) Sustained steady operation.
[0018]
The transition state of the absolute pressure in the front chamber formed by the air supply / exhaust fan started according to the above flowchart is shown in FIG.
[0019]
As shown in the figure, the exhaust fan 26 reaches the rated operation after Te time (110 seconds), whereas the supply fan 25 reaches the rated operation after a longer Ts time (230 seconds). The difference in rotational speed between the air supply fan 25 and the exhaust fan 26 during that time increases with time.
[0020]
For this reason, by following the above-described process, there is a problem in the front chamber 22 that the maximum chamber pressure drops by 350 (Pa) excessively until the air supply fan 25 reaches normal operation.
[0021]
Such an excessive decrease in the room pressure is a very serious problem as an operation mode in a BH facility because it may cause an accident that the interior material is peeled off.
[0022]
[Problems to be solved by the invention]
The present invention has been studied in view of the above problems, and the air supply amount maintains a predetermined amount difference with respect to the exhaust amount, thereby stabilizing the room pressure of the facility and the air flow between the facilities. Provides a room pressure control method in an advanced clean facility that maintains the room pressure so that the pressure is always in one direction.
[0023]
[Means for Solving the Problems]
According to a first aspect of the present invention, the room pressure control method in the highly clean facility maintains a predetermined room pressure by mutually controlling an air supply fan that supplies air to the facility and an exhaust fan that exhausts air from the facility. A room pressure control method in an advanced clean facility using an air supply fan and an exhaust fan having the same starting characteristics so that the air supply amount maintains a predetermined amount difference with respect to the exhaust amount. A time difference between starting the exhaust fan first before starting and then starting the air supply fan is provided by a timer , and the rotational speed of the exhaust fan and air supply fan is made different, and the BH facility is started. Even in this case, a stable differential pressure is maintained without causing an excessive decrease in the chamber pressure. It can be easily adjusted by changing the startup time setting of the supply / exhaust fan and changing the rotation speed of the supply / exhaust fan.
[0024]
The room pressure control method in an advanced clean facility according to claim 2 communicates via a door by mutually controlling an air supply fan that supplies air to the facility and an exhaust fan that exhausts air from the facility. A chamber pressure control method in an advanced clean facility in which the front chamber and the working chamber are maintained at a predetermined chamber pressure so that the air supply amount in each chamber maintains a predetermined amount difference with respect to the exhaust amount Using an air supply fan and an exhaust fan with the same starting characteristics, a timer is used to set a time difference between starting the exhaust fan first before starting and then starting the air supply fan, and rotation of the exhaust fan and air supply fan. The exhaust flow rate of each of the front chamber and the work chamber should be adjusted with a variable air flow rate device so that the difference in the number of the front chamber and the volume difference in the front chamber maintains a predetermined chamber pressure difference with respect to the volume difference in the work chamber. And when activating the BH facility Holds the differential pressure is stabilized without also generating the excessive decrease in chamber pressure, and the flow of air between the front chamber and the working chamber always in one direction. It can be easily adjusted by changing the startup time setting of the supply / exhaust fan and changing the rotation speed of the supply / exhaust fan.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
The room pressure control method in an advanced clean facility according to the present invention includes a front chamber and a work chamber communicated via a door by mutually controlling an air supply fan that supplies air to the facility and an exhaust fan that exhausts air from the facility. In a room pressure control method in an advanced clean facility maintained at a predetermined room pressure, an air supply fan having the same start-up characteristic is used so that the air supply amount in each chamber maintains a predetermined amount difference with respect to the exhaust amount. Using the exhaust fan, a time difference between starting the exhaust fan first and starting the air supply fan after the start is provided by a timer , and the rotation speed of the exhaust fan and the air supply fan is made different. The exhaust flow rate of each of the front chamber and the working chamber is adjusted by a variable air flow device so that the chamber volume difference maintains a predetermined chamber pressure difference with respect to the working chamber volume difference.
[0026]
As a result, even when the BH facility is activated, a stable differential pressure can be maintained without causing an excessive decrease in the chamber pressure, and the air flow between the front chamber and the working chamber can always be maintained in one direction.
[0027]
Hereinafter, embodiments of the present invention will be described with reference to the drawings. In order to facilitate understanding, the same reference numerals are given to the same devices and the like as in the past.
[0028]
FIG. 1 shows a control circuit diagram of the BH facility 20. The BH facility 20 includes a breeding room 21, a front room 22, and a door 23 therebetween, as in the conventional example. And it is the same also to arrange | position the safety cabinet 24 grade | etc., In the breeding room 21. FIG.
[0029]
The BH facility 20 is provided with an air supply fan 25 and an exhaust fan 26 to supply outside air and exhaust air from the room, and a constant air volume device 27 disposed between the air supply fan 25 and each room. The high-performance filter 28 and the high-performance filter 28 disposed between each chamber and the exhaust fan 26 and the variable air flow device 29 are also combined with the high-performance filter 28 disposed between the safety cabinet 24 and the exhaust fan 26. In addition, the operation is controlled in the same manner as in the conventional example so that the contaminated air is not discharged to the outside.
[0030]
Further, the breeding room 21 and the front room 22 keep the supply air volume constant by the constant air volume devices 27 and the flow rate of the variable air volume device 29 so that the breeding room 21 maintains a negative pressure with respect to the front room 22. Are adjusted with each other by a differential pressure signal of the differential pressure gauge 30 and controlled to always maintain a predetermined differential pressure, thereby forming an air flow from the front chamber 22 to the breeding room 21.
[0031]
The control circuit according to the present invention not only can change the rated rotation speed of the supply / exhaust fans 25 and 26 by the inverter 31 and control the rise time from the start to the rated rotation as in the prior art. Thus, a timer 33 is connected to the starting circuit of the supply / exhaust fans 25 and 26.
[0032]
Therefore, in the present invention, by setting the timers 33 to be different from each other, even if the power supply / exhaust fans 25 and 26 are simultaneously turned on, the supply / exhaust fans 25 and 26 can be started separately. .
[0033]
The above control for the air supply / exhaust fan is performed by adjusting the settings of the inverter 31 and the timer 33 in the control panel 32, thereby achieving the ideal operation when the BH facility 20 is started as follows. .
[0034]
FIG. 2 is a flowchart showing an embodiment of the room pressure control method according to the present invention. From the start of adjustment to the continuation of steady operation, in the illustrated flowchart developed in the following order, air supply / exhaust is used as the start. The settings before starting the fan are made.
[0035]
(101) Setting the rated rotational speed of the supply / exhaust fan. The rated rotational speed (Rs) of the air supply fan 25 and the rated rotational speed (Re) of the exhaust fan 26 are set to Re> Rs.
[0036]
(102) Setting of the starting time until the rated rotational speed of the supply / exhaust fan is reached. The start time (Ts) of the air supply fan 25 and the start time (Te) of the exhaust fan 26 are set to Ts = Te.
[0037]
(103) Setting of a timer for the supply / exhaust fan. The operating time of the air supply fan 25 = T and the operating time of the exhaust fan 26 = 0 are set. (104) The supply / exhaust fan is switched on.
[0038]
(105) The exhaust fan is turned on. The exhaust fan 26 starts immediately when the operation time = 0, and negative pressure is generated in the room.
[0039]
(106) The power supply fan is turned on. The supply fan 25 starts after the operation time = T, and the negative pressure is maximized without being extremely reduced.
[0040]
(107) Rated operation of the exhaust fan 26 after Te time. Negative pressure is reduced by increasing the rotation speed of the air supply fan.
[0041]
(108) Rated operation of the air supply fan 25 after Ts + T time. It converges to the desired negative pressure due to the difference in the rotation speed of the supply and exhaust fans. (109) Continuous operation is continued.
[0042]
The supply / exhaust fan operated according to the above flowchart forms a transition state of absolute pressure as shown in FIG. 3 in the front chamber.
[0043]
As shown in the figure, the exhaust fan 26 is activated at the same time as the switch is turned on, so that negative pressure is generated in the room against the outside air. The negative pressure continues to increase until the air supply fan 25 starts after time T, but when the air supply fan 25 starts, the negative pressure stops increasing, and the negative pressure increases as the number of rotations of the air supply fan 25 increases. Reduced.
[0044]
In the present embodiment, exhaust is continued by the operation of the exhaust fan 26 until the supply fan 25 starts up after time T, and the negative pressure continues to increase. During this time, the pressure difference formed between the exhaust fan and the air supply fan 25 increases from zero to about 120 (Pa) where the air supply fan 25 starts up. Is the same (Ts = Te), the pressure difference is maintained until the exhaust fan 26 reaches the rated operation.
[0045]
Although the absolute pressure in the front chamber is reduced by this operation control, since the increase in the pressure difference is stopped by the operation of the air supply fan 25, it is held at a constant value. It stops without being lowered to an extreme value, draws a gentle curve as shown in the figure, reduces the negative pressure, reaches the rated operation of the air supply fan 25 and converges to a predetermined negative pressure. Yes.
[0046]
As described above, in this embodiment, an exhaust fan and an air supply fan having the same starting characteristics are started with a difference in start time, so that a predetermined amount is set between the air supply amount and the exhaust amount. By maintaining the difference, a stable differential pressure is maintained without causing an excessive decrease in the room pressure when the BH facility is activated.
[0047]
In addition, the above operating state is similarly implemented in the breeding room. For this reason, the breeding room 21 and the front room 22 are each configured to maintain a negative pressure due to a flow rate difference while adjusting the exhaust flow rate by the variable air volume device 29. It is maintained in a very stable state.
[0048]
Accordingly, the differential pressure between the chambers, which are installed between the breeding room 21 and the front chamber 22 and are mutually adjusted by the differential pressure signal of the differential pressure gauge 30, is also because the chamber pressure of each chamber is stable. It will be held in a stable state, without causing mutual interference in the control system, and the air flow from the front chamber 22 to the breeding room 21 can be formed with little disturbance.
[0049]
In the above embodiment, as a means for maintaining a predetermined amount difference between the air supply amount and the exhaust amount, the exhaust fan and the air supply fan having the same start characteristics are started with a difference in start time. However, in the room pressure control method in the highly clean facility according to the present invention, the same function can be established in other means.
[0050]
The first of other embodiments is a means for forming a predetermined amount difference in the BH facility by providing a difference in the rotational speed between the exhaust fan and the supply fan.
[0051]
In the present embodiment, as clearly shown by the fan rotation speed displayed in FIG. 3, the rotation speed of the exhaust fan is set to be larger than the rotation speed of the air supply fan by a predetermined value by setting the inverter. By controlling and maintaining the difference in the supply air volume due to the difference in the rotational speed at a predetermined value, a predetermined negative pressure is formed in the BH facility against the outside air.
[0052]
At this time, the starting characteristics (setting of the time from starting to reaching the rated rotational speed) formed in the supply / exhaust fan are the same. However, starting the exhaust fan first may cause the BH facility to be exposed to the outside air. Since the pressure is preliminarily formed and determined, it is determined by what kind of negative pressure is generated against the outside air at the initial stage in the BH facility.
[0053]
As described above, the room pressure control method in an advanced clean facility according to the present invention is an air supply fan having the same starting characteristics so that the air supply amount maintains a predetermined amount difference with respect to the exhaust amount in the advanced clean facility. And the exhaust fan, the time difference for starting the exhaust fan first and starting the air supply fan after the start is provided by a timer, and the rotational speed of the exhaust fan and the air supply fan is made different, and When the BH facility is activated, the exhaust flow rate of the front chamber and the working chamber is adjusted by the variable air flow rate device so that the difference in the amount of the front chamber is maintained at a predetermined pressure difference from the amount of the work chamber. In addition, the room pressure of the facility is stabilized without causing an excessive decrease in the room pressure, and the room pressure is maintained so that the air flow between the facilities is always in one direction.
[0054]
As described above, the present invention has been described in detail based on the embodiments. However, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the invention. It is natural.
[0055]
【The invention's effect】
According to a first aspect of the present invention, the room pressure control method in the highly clean facility maintains a predetermined room pressure by mutually controlling an air supply fan that supplies air to the facility and an exhaust fan that exhausts air from the facility. A room pressure control method in an advanced clean facility using an air supply fan and an exhaust fan having the same starting characteristics so that the air supply amount maintains a predetermined amount difference with respect to the exhaust amount. The time difference between starting the exhaust fan first and starting the air supply fan after the start is provided by a timer, and the difference between the rotation speeds of the exhaust fan and the air supply fan is characteristic. In this case, it is possible to maintain a stable differential pressure without causing an excessive decrease in the chamber pressure. There is an effect that it can be easily adjusted by changing the start time setting of the supply / exhaust fan and changing the setting of the rotation speed of the supply / exhaust fan. Specifically, since the exhaust fan is activated first, negative pressure is generated in the facility against the outside air, and this negative pressure continues to increase until the air supply fan is subsequently activated, but the air supply fan is activated. Then, the increase in negative pressure stops and the negative pressure is reduced as the rotation speed of the supply air fan increases, and this operation control reduces the absolute pressure of the facility, but the increase in the pressure difference occurs during operation of the supply air fan. Since it is held at a constant value after being stopped, the maximum value of the absolute pressure that decreases is stopped without being reduced to an extreme value as in the past, and the negative pressure is gently reduced to supply The rated operation of the air fan can be reached and converged to a predetermined negative pressure, and a stable differential pressure can be maintained without causing an excessive decrease in the room pressure when the facility is started.
[0056]
The room pressure control method in an advanced clean facility according to claim 2 communicates via a door by mutually controlling an air supply fan that supplies air to the facility and an exhaust fan that exhausts air from the facility. A chamber pressure control method in an advanced clean facility in which the front chamber and the working chamber are maintained at a predetermined chamber pressure so that the air supply amount in each chamber maintains a predetermined amount difference with respect to the exhaust amount Using an air supply fan and an exhaust fan with the same starting characteristics, a timer is used to set a time difference between starting the exhaust fan first before starting and then starting the air supply fan, and rotation of the exhaust fan and air supply fan. The exhaust flow rate of each of the front chamber and the work chamber should be adjusted with a variable air flow rate device so that the difference in the number of the front chamber and the volume difference in the front chamber maintains a predetermined chamber pressure difference with respect to the volume difference in the work chamber. Because it is characterized by, to activate the BH facility It holds the differential pressure is stabilized without generating an excessive decrease of the room pressure even when, and the flow of air between the front chamber and the working chamber always provide an advantage that in one direction. There is an effect that it can be easily adjusted by changing the start time setting of the supply / exhaust fan and changing the setting of the rotation speed of the supply / exhaust fan. Specifically, since the exhaust fan is activated first, negative pressure is generated in the facility against the outside air, and this negative pressure continues to increase until the air supply fan is subsequently activated, but the air supply fan is activated. Then, the increase in negative pressure stops and the negative pressure is reduced as the rotation speed of the supply air fan increases, and this operation control reduces the absolute pressure of the facility, but the increase in the pressure difference occurs during operation of the supply air fan. Since it is held at a constant value after being stopped, the maximum value of the absolute pressure that decreases is stopped without being reduced to an extreme value as in the past, and the negative pressure is gently reduced to supply It can reach the rated operation of the air fan, can be converged to a predetermined negative pressure, can maintain a stable differential pressure without causing an excessive decrease in the room pressure when starting the facility, and This operating state is also the same in the work room. The front chamber, while adjusting the flow rate of the exhaust gas by Henfu weight unit, respectively, be configured so as to maintain the negative pressure by the flow rate difference, it is possible to maintain a very stable state at the time of startup of each chamber.
[Brief description of the drawings]
FIG. 1 is a control circuit diagram of a room pressure control method for an advanced clean facility according to the present invention. FIG. 2 is a flowchart of a room pressure control method for an advanced clean facility according to the present invention. FIG. 4 is a control circuit diagram of a conventional room pressure control method for a highly clean facility. FIG. 5 is a flowchart of a conventional room pressure control method for a highly clean facility. Room pressure status by clean room pressure control method 【Explanation of symbols】
20BH facility, 21 rearing room, 22 front room, 23 door, 24 safety cabinet, 25 air supply fan, 26 exhaust fan, 27 constant air volume device, 28 high performance filter, 29 variable air volume device, 30 differential pressure gauge, 31 inverter, 32 Control panel, 33 timer,

Claims (2)

A room pressure control method in an advanced clean facility that maintains a predetermined room pressure by mutually controlling an air supply fan that supplies air to the facility and an exhaust fan that exhausts air from the facility. In order to maintain a predetermined difference with respect to the air flow, using a supply air fan and an exhaust fan with the same starting characteristics, the time difference between starting the exhaust fan first and starting the air supply fan is started by a timer. A room pressure control method in an advanced clean facility characterized by providing a difference in rotational speed between the exhaust fan and the air supply fan. In an advanced clean facility where the air supply fan that supplies air to the facility and the exhaust fan that exhausts air from the facility are mutually controlled to maintain the front room and work room communicated via the door at a predetermined room pressure. a chamber pressure control method, so that the amount of supply air in each chamber to maintain a predetermined amount difference with respect to emissions, starting characteristics by using the exhaust fan and the same air supply fan, exhaust fan to the starting The time difference between starting the air supply fan and starting the air supply fan after that is provided by a timer , and the rotational speed of the exhaust fan and air supply fan is varied, and the amount difference in the front chamber is the amount difference in the work room. A room pressure control method in an advanced clean facility, characterized in that the exhaust flow rate in each of the front chamber and the working chamber is adjusted by a variable air flow device so as to maintain a predetermined chamber pressure difference.

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