JP2002039580A - Method of controlling indoor pressure in high-purity clean facility - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide method of controlling indoor pressure in a high-purity clean facility which stabilizes the room pressure of the facility and keeps the room pressure so that the stream of the air flow between facilities is directed always in one direction, by the amount of air supply keeping a specified quantitative difference to the amount of exhaust. SOLUTION: In this method of controlling the room pressure in a high-purity clean facility which keeps a front room 22 and a work room 21 at a prescribed room pressure to outside air by alternately controlling an air supply fan 25 for supplying the facility 20 with air and an exhaust fan 26 for exhausting air from the facility, the starting times of the air supply fan 25 and the exhaust fan 26 are staggered so that the amount of air supply keeps a prescribed quantitative difference in the amount exhausted, and also the front room 22 and the work room 21 keep the prescribed difference in room pressure, and differential pressure is kept, without generating surplus drop of the room pressure when the user starts up a BH facility, and the stream of the air flow between the front room and the work room is always kept in one direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling a room pressure in an advanced cleaning facility, and more particularly, to stabilizing a room pressure in the facility by maintaining a predetermined difference between an air supply amount and an exhaust amount. The present invention relates to a room pressure control method in an advanced cleaning facility that maintains a room pressure so that an air flow between the facilities is unidirectional.

[0002]

2. Description of the Related Art In a production facility that requires a high degree of cleanliness or an industrial facility that handles pollutants, cross-contamination of air generated between the room and another room or the outside becomes a problem. In order to avoid this problem, the room pressure is controlled so that the air flow between the rooms is unidirectional.

[0003] In buildings such as pharmaceutical manufacturing plants, food factories and semiconductor manufacturing plants, which are one of such production facilities, room pressure must be reduced because dust and germs must be prevented from entering from outside. It is controlled so that a positive pressure is applied to the outside air or the surrounding chamber.

On the other hand, in a specialty chemical factory or a biohazard countermeasure facility (hereinafter referred to as a BH facility), it is necessary to prevent room air from leaking to the outside. Room pressure control is performed to maintain the pressure.

Conventional room pressure control is carried out by a control circuit shown in FIG. 4. In starting and stopping the fan in the above-described process, a required room pressure is maintained between the room and another room. In addition, the following operation control was adopted.

[0006] The BH facility 20 comprises a rearing room 21 and a front room 22, which are connected by a door 23. Further, a safety cabinet 24 and the like are arranged in the breeding room 21, and are configured so that predetermined operations can be performed.

In the BH facility 20, supply of conditioned air and exhaust from the room are performed 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 of the chambers, respectively. The air volume devices 29 are arranged respectively. A high-performance filter 28 is also provided between the safety cabinet 24 and the exhaust fan 26 so as not to discharge the contaminated air to the outside.

The breeding room 21 and the front room 22 maintain a constant supply air volume by respective constant air volume devices 27 and a differential pressure from a differential pressure gauge 30 disposed between the breeding room 21 and the front room 22. The flow rates of the variable air volume devices 29 are adjusted with each other so that the rearing room 21 always maintains a negative pressure with respect to the front room 22 by the signal. Thereby, the pressure between the rearing room 21 and the front room 22 is controlled so as to always maintain a differential pressure of, for example, 30 (Pa), and the flow of air from the front room 22 to the rearing room 21 is formed. ing.

However, in the BH facility, it is necessary to stop the air conditioning when the work content is changed or the like. After the change, the fan is restarted immediately so that the room pressure does not leak to the outside. It was necessary to perform room pressure control for returning the pressure to a negative pressure with respect to the outside air.

For this reason, in the above control circuit, by employing the inverter 31 for the air supply / exhaust fans 25 and 26, the rated speed of the air supply / exhaust fan can be changed, and from the start to the rated speed. The rise time can also be controlled, and by setting the start-up characteristics of the air supply / exhaust fans at the time of start-up to be different from each other, the normal operation state at the same time as the restart of the BH facility 20 is directed.

These controls are performed by adjusting the setting of the inverter 31 in the control panel 32. FIG. 5 is an example of a conventional control mode, and FIG.
This is a transition state of the absolute pressure in the front chamber controlled by this.

The adjustment and control in the control panel 32 are performed in accordance with the flowchart of FIG. 5, and are performed in the following order from the start of the adjustment to the continuation of the steady operation.

[0013] Setting of the rated rotation speed of the supply / exhaust fan. The rated rotation speed (Rs) of the air supply fan 25 and the rated rotation speed (Re) of the exhaust fan 26 are set so that Re> Rs.

[0014] Setting of a startup time until the rated rotation speed of the supply / exhaust fan is reached. Starting time of the air supply fan 25 (T
s) and the startup time (Te) of the exhaust fan 26 are set to Ts> Te.
Set to.

[0015] Simultaneous start-up and power-on of the air supply and exhaust fans
Since the speed at which the number of rotations of the air supply / exhaust fan rises differs, negative pressure gradually increases in the room.

The rated operation of the exhaust fan 26 after Te time. Negative pressure after Te time is greatest

The rated operation of the air supply fan 25 after the time Ts. It converges to a desired negative pressure due to the difference in the number of rotations of the supply and exhaust fans. Sustained steady operation.

FIG. 6 shows the transition of the absolute pressure in the front chamber formed by the supply / exhaust fan started according to the above flowchart.

As shown, the exhaust fan 26 reaches the rated operation after Te time (110 seconds), whereas the air supply fan 25 reaches the rated operation after a longer Ts time (230 seconds). Therefore, the air supply fan 25 during that time
And the rotation speed of the exhaust fan 26 increases with time.

For this reason, by following the above-described progress, in the front chamber 22, there is a problem that the chamber pressure is excessively reduced by a maximum of 350 (Pa) before the air supply fan 25 operates normally. I have.

Such an excessive decrease in the room pressure may cause an accident such as peeling of the interior material, and is therefore a very serious problem as an operation mode in the BH facility.

[0022]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above problems, and has been made to stabilize the room pressure of a facility by maintaining a predetermined difference between the amount of supplied air and the amount of exhaust. In addition, the present invention provides a room pressure control method in an advanced cleaning facility that maintains the room pressure so that the air flow between the facilities is always in one direction.

[0023]

According to a first aspect of the present invention, there is provided a method for controlling room pressure in an advanced cleaning facility, wherein a supply fan for supplying air to the facility and an exhaust fan for discharging air from the facility are mutually controlled. In the room pressure control method in an advanced cleaning facility in which a predetermined room pressure is maintained by performing the above operation, the air supply fan and the exhaust fan are mutually operated so that the air supply amount maintains a predetermined amount difference with respect to the exhaust amount. It is characterized by controlling,
Even when the BH facility is activated, the stabilized differential pressure is maintained without excessively lowering the room pressure.

According to a second aspect of the present invention, there is provided a method for controlling a room pressure in an advanced cleaning facility, wherein the air supply fan for supplying air to the facility and the exhaust fan for exhausting air from the facility are mutually controlled to open the door. A room pressure control method in an advanced cleaning facility in which a front room and a working room that are communicated with each other are maintained at a predetermined room pressure, wherein an air supply amount in each room maintains a predetermined amount difference with respect to an exhaust amount. In addition, the air supply fan and the exhaust fan are mutually controlled while maintaining a predetermined room pressure difference with respect to the work room volume difference in the front room, and the BH facility is started. In this case, the pressure difference is kept stable without excessively lowering the chamber pressure, and the air flow between the front chamber and the working chamber is always in one direction.

According to a third aspect of the present invention, there is provided a method for controlling a room pressure in an advanced cleaning facility according to the first or second aspect, wherein the difference between the amount of supply air and the amount of exhaust air is determined by a starting characteristic. Is characterized by using the same air supply fan and exhaust fan, and maintaining it by providing a time lag to start.In addition to the above functions, it is easily adjusted by changing the start time setting of the air supply and exhaust fan You can do it.

According to a fourth aspect of the present invention, there is provided a method of controlling room pressure in an advanced cleaning facility according to any one of the first to third aspects, wherein the difference between the amount of supply air and the amount of exhaust air is different. Is maintained by the difference in the number of revolutions between the air supply fan and the exhaust fan.
It can be easily adjusted by changing the setting of the rotation speed of each inverter of the air supply / exhaust fan.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A room pressure control method in an advanced cleaning facility according to the present invention controls a front fan and a work room by mutually controlling an air supply fan for supplying air to the facility and an exhaust fan for exhausting air from the facility. In a room pressure control method in an advanced cleaning facility maintaining a predetermined room pressure, the air supply fan and the exhaust fan are mutually controlled so that the air supply amount maintains a predetermined amount difference with respect to the exhaust amount. Also, a predetermined chamber pressure difference is maintained between the front chamber and the working chamber.

Thus, even when the BH facility is started, a stable differential pressure is maintained without excessively lowering the room pressure, and the air flow between the front chamber and the working chamber is always in one direction. Can be maintained.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. To facilitate understanding, the same reference numerals are given to the same devices and the like as those in the related art.

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. The same applies to the arrangement of the safety cabinet 24 and the like in the breeding room 21.

The BH facility 20 is provided with an air supply fan 25.
And an exhaust fan 26 are provided to supply outside air and exhaust air from the room. A constant air volume device 27, a high-performance filter 28, and an exhaust fan are provided between the air supply fan 25 and each room. The high-performance filter 28 and the variable air volume device 29 disposed between the safety cabinet 24 and the exhaust fan 26 also operate together with the high-performance filter 28 disposed between the safety cabinet 24 and the exhaust fan 26 in the same manner as in the conventional example. The operation is controlled so that air is not discharged to the outside.

The breeding room 21 and the front room 22 are supplied with a constant air volume device 27 so as to maintain a constant supply air volume and a variable air volume device such that the breeding room 21 maintains a negative pressure with respect to the front room 22. The flow rate at 29 is mutually adjusted by the differential pressure signal from the differential pressure gauge 30, and is controlled so that a predetermined differential pressure is always maintained, thereby forming an air flow from the front room 22 to the breeding room 21. ing.

The control circuit according to the present invention not only allows the inverter 31 to change the rated rotation speed of the supply / exhaust fans 25 and 26 and controls the rise time from the start to the rated rotation by the inverter 31 as in the conventional case. In addition to this,
A timer 33 is connected to a start circuit of the air supply / exhaust fans 25 and 26.

Therefore, in the present invention, by setting the timer 33 to be different from each other, even if the air supply and exhaust fans 25 and 26 are simultaneously turned on, the air supply and exhaust fans 25 and 26 are started separately. I can do it.

The above control of 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 at the time of starting the BH facility 20 as follows. are doing.

FIG. 2 is a flowchart showing an embodiment of the room pressure control method according to the present invention. From the start of the adjustment to the continuation of the steady operation, in the flowchart shown in FIG. The setting before starting the air supply / exhaust fan is performed.

(101) Setting of the rated rotation speed of the supply / exhaust fan. The rated rotation speed (Rs) of the air supply fan 25 and the rated rotation speed (Re) of the exhaust fan 26 are set so that Re> Rs.

(102) Setting of starting time until reaching the rated rotation speed of the air supply / exhaust fan. The activation time (Ts) of the air supply fan 25 and the activation time (Te) of the exhaust fan 26 are represented by Ts.
= Te.

(103) Setting of timer for air supply / exhaust fan. The operation time of the air supply fan 25 = T and the operation time of the exhaust fan 26 = 0 are set. (104) Switch on the supply / exhaust fan.

(105) The exhaust fan is turned on. The exhaust fan 26 is started immediately when the operation time = 0, and a negative pressure is generated in the room.

(106) The power supply of the air supply fan is turned on. The air supply fan 25 is started after the operation time = T, and the negative pressure is maximized without extremely decreasing.

(107) Exhaust fan 26 after Te time
Rated operation. The negative pressure is reduced by increasing the rotation speed of the air supply fan.

(108) Rated operation of the air supply fan 25 after Ts + T time. It converges to a desired negative pressure due to the difference in the number of rotations of the supply and exhaust fans. (109) Sustained steady operation.

The supply / exhaust fan operated in accordance with the above flow chart forms a transition state of the absolute pressure in the front room as shown in FIG.

Since the exhaust fan 26 is started at the same time as the switch-on as shown in the figure, a negative pressure is generated in the room with respect to the outside air. The negative pressure continues to increase until the air supply fan 25 starts after the time T. However, when the air supply fan 25 starts, the negative pressure stops increasing, and the negative pressure decreases as the rotation speed of the air supply fan 25 increases. Reduced.

In the present embodiment, the exhaust is continued by the operation of the exhaust fan 26 and the increase in the negative pressure is continued until the air supply fan 25 is started after the time T. The pressure difference formed between the exhaust fan and the air supply fan 25 during this time is about 120 (P) when the air supply fan 25 starts up from zero.
a) After that, the pressure difference is maintained until the exhaust fan 26 reaches rated operation by setting the startup characteristics of the supply and exhaust fans to the same (Ts = Te).

Although the absolute pressure of the front chamber is reduced by this operation control, since the increase in the pressure difference is stopped after the operation of the air supply fan 25 is stopped, the maximum value of the reduced absolute pressure is It stops without being reduced to an extreme value as in the prior art, draws a gentle curve as shown to reduce the negative pressure, and reaches the rated operation of the air supply fan 25 to reach a predetermined negative pressure. It is converging.

As described above, in this embodiment, the exhaust fan and the air supply fan having the same starting characteristics are started with a difference in the start time, so that the air supply amount and the exhaust amount can be changed. By maintaining a predetermined amount difference, a stable differential pressure is maintained without excessively lowering the room pressure even when the BH facility is started.

The above-mentioned operation state is also carried out in the breeding room. For this reason, the breeding room 21 and the front room 22 are configured so as to maintain the negative pressure due to the flow rate difference while adjusting the exhaust flow rate by the variable air volume device 29, respectively. It is maintained in a very stable state.

Therefore, the differential pressure between the respective rooms installed between the breeding room 21 and the front room 22 and adjusted by the differential pressure signal of the differential pressure gauge 30 is also stable. Therefore, it is maintained in a stable state, and no mutual interference occurs in the control system.
The air flow to 1 can also be formed with little disturbance.

In the above embodiment, as a means for maintaining a predetermined difference between the supply air amount and the exhaust air amount, there is a difference in the start time between the exhaust fan and the air supply fan having the same startup characteristics. However, in the method of controlling room pressure in an advanced cleaning facility according to the present invention, a similar function can be established by other means.

The first of the other embodiments is means for forming a predetermined amount difference in the BH facility by giving a difference between the rotation speeds of the exhaust fan and the air supply fan.

In this embodiment, as is apparent from the fan rotation speed shown in FIG. 3, the rotation speed of the exhaust fan is made larger than the rotation speed of the air supply fan by a predetermined value by setting the inverter. A predetermined negative pressure is generated in the BH facility with respect to the outside air by maintaining the difference in the supplied air volume due to the difference in the number of revolutions at a predetermined value.

At this time, the start-up characteristics (setting of the time from start-up to reaching the rated rotation speed) formed in the air supply / exhaust fan are the same, but starting the exhaust fan first makes it possible for the BH facility to open air. On the other hand, since the negative pressure will be formed in advance, whether the start should be set to the same or a time difference should be determined at the initial stage in the BH facility, It is determined by whether it is formed.

The second embodiment of the present invention is a means for forming a predetermined amount difference in the BH facility by reducing the air supply amount of the air supply fan with respect to the exhaust air amount of the exhaust fan.

In this embodiment, a load circuit is connected between the inverters for controlling the air supply and exhaust fans, and the air supply fan is set to always have a smaller output value than the exhaust fan. The fans have the same startup characteristics and maintain a constant difference in the amount of air supply and exhaust air.

Therefore, by configuring the circuit so that the air supply fan starts after the exhaust fan starts,
After the negative pressure is created in the BH facility against the outside air by the operation of the exhaust fan, the supply fan operates in a reduced state while following the exhaust fan, and the desired negative pressure is maintained for the outside air. Is controlled to be

As described above, the method of controlling the room pressure in the advanced cleaning facility according to the present invention provides the air supply fan and the exhaust fan in the advanced cleaning facility such that the air supply amount maintains a predetermined difference from the exhaust amount. And a predetermined room pressure difference is maintained between the front room and the work room, so that even when the BH facility is activated, the room pressure in the facility does not excessively decrease. The pressure is stabilized and the room pressure is maintained so that the air flow between the facilities is always in one direction.

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 embodiments, and various changes may be made without departing from the spirit of the invention. Of course it is possible.

[0060]

According to the first aspect of the present invention, a room pressure control method in an advanced cleaning facility is characterized in that a predetermined value is obtained by mutually controlling an air supply fan for supplying air to the facility and an exhaust fan for discharging air from the facility. In the room pressure control method in an advanced cleaning facility that maintains the room pressure, the air supply fan and the exhaust fan are mutually controlled so that the air supply amount maintains a predetermined amount difference with respect to the exhaust amount. Because of the feature, even when the BH facility is activated, an effect of maintaining a stabilized differential pressure without excessively lowering the room pressure is exhibited.

According to a second aspect of the present invention, a method of controlling room pressure in an advanced cleaning facility includes controlling an air supply fan for supplying air to the facility and an exhaust fan for exhausting air from the facility to open the door. A room pressure control method in an advanced cleaning facility in which a front room and a working room that are communicated with each other are maintained at a predetermined room pressure, wherein an air supply amount in each room maintains a predetermined amount difference with respect to an exhaust amount. In addition, the BH facility is started since the air supply fan and the exhaust fan are mutually controlled while maintaining the predetermined room pressure difference with respect to the work room volume difference in the front room. While maintaining the stable differential pressure without causing an excessive decrease in the room pressure,
This has the effect of making the air flow between the anterior chamber and the work chamber always one-way.

According to a third aspect of the present invention, there is provided a method for controlling a room pressure in an advanced cleaning facility, wherein the difference between the amount of supply air and the amount of exhaust gas is determined by a starting characteristic. Is characterized by using the same air supply fan and exhaust fan and maintaining it by providing a time difference in starting, in addition to the above effects, easily by changing the time setting of the start of the air supply and exhaust fan It has an adjustable effect.

A room pressure control method in an advanced cleaning facility according to a fourth aspect of the present invention is the room pressure control method according to any one of the first to third aspects, wherein the difference between the supply air amount and the exhaust air amount is different. Is maintained by the difference between the rotation speeds of the air supply fan and the exhaust fan.In addition to the above effects, the effect that can be easily adjusted by changing the setting of the rotation speed of each inverter of the air supply and exhaust fans is provided. I'm playing.

[Brief description of the drawings]

FIG. 1 is a control circuit diagram in a room pressure control method of an advanced cleaning facility according to the present invention.

FIG. 2 is a flowchart of a room pressure control method for an advanced cleaning facility according to the present invention.

FIG. 3 is a room pressure state according to a room pressure control method of an advanced cleaning facility according to the present invention.

FIG. 4 is a control circuit diagram in a conventional room pressure control method for an advanced cleaning facility.

FIG. 5 is a flowchart of a conventional room pressure control method for an advanced cleaning facility.

FIG. 6: Room pressure state by the conventional room pressure control method of the advanced cleaning facility

[Explanation of symbols]

20 BH facilities, 21 breeding rooms, 22 front rooms, 2
3 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 (4)

[Claims] 1. A room pressure control method in an advanced cleaning facility that maintains a predetermined room pressure by mutually controlling an air supply fan that supplies air to a facility and an exhaust fan that exhausts air from the facility. A room pressure control method in an advanced cleaning facility, characterized by mutually controlling an air supply fan and an exhaust fan such that an air volume maintains a predetermined difference with respect to an exhaust gas amount. 2. An air supply fan for supplying air to a facility and an exhaust fan for exhausting air from the facility are mutually controlled, so that a front chamber and a working chamber connected through a door are maintained at a predetermined room pressure. A room pressure control method in an advanced cleaning facility, wherein the air supply amount in each room maintains a predetermined amount difference with respect to the exhaust amount, and the air amount difference in the front room is a predetermined amount difference with respect to the work room amount difference. A room pressure control method in an advanced cleaning facility, characterized by mutually controlling an air supply fan and an exhaust fan while maintaining a room pressure difference. 3. The method according to claim 1, wherein the difference between the supplied air amount and the exhaust air amount is maintained by providing a time difference in the start-up using an air supply fan and an exhaust fan having the same starting characteristics. Or the room pressure control method in the advanced cleaning facility according to 2. 4. The high-purity cleaning device according to claim 1, wherein the difference between the amount of supply air and the amount of exhaust air is maintained by the difference between the rotation speeds of the air supply fan and the exhaust fan. Room pressure control method in facilities.