JPH10300012A - Deaeration apparatus and operation thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a higher energy saving effect of a deaeration apparatus by controlling the number of revolutions of a vacuum pump based on a detection value of a pressure sensor provided in a deairing means or in a vacuum suction line and that of a pump for supplying a liquid to be deaired to the deairing means. SOLUTION: A supply line 5 provided with a pump 18 for circulating a liquid to be deaired to one side of a film deairing module 4 formed out of a gas permeable film such as hollow yarn membrain as deairing means 3 of a deaeration apparatus and the pump 18 is connected to a controller 16 through a signal line 15. The vacuum pump 7 is connected to the film deairing module 4 by a vacuum suction line 10, which 10 is provided with a pressure sensor 11 to sense the vacuum pressure in the film deairing module 4 and an air introduction valve 14 to prevent the generation of noises in a transient state. The controller 16 contains an inverter, a timer and an arithmetic means to control the number of revolutions of the vacuum pump 7 and the pump 18 for circulating the liquid to be deaired based on a detection signal of the pressure sensor 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deaeration device capable of improving the energy saving effect and a method of operating the same.

[0002]

2. Description of the Related Art As is well known, the supply of water to cooling and heating equipment such as boilers and coolers, or water supply pipes of buildings, etc. is a measure to prevent corrosion of these equipments and red water due to corrosion of water supply piping systems of buildings and the like. It is necessary to incorporate a deaerator.
For example, FIG. 6 shows a building water supply system provided with a deaerator, and the building water supply system shown in FIG.
2, water supply line 33, deaerator 34 and deaeration line 3
5. In these configurations, the deaeration operation is performed while circulating the water in the elevated water tank 31 through the deaeration line 35 by the operation of the deaerator 34, and if necessary,
Water is supplied to the load 32 through the water supply line 33. Therefore, the inside of the water supply line 33 is always
It will be filled with degassed water, and the generation of red water can be prevented. A circulation pump 36 and a valve 37 are inserted in the deaeration line 35, and a water receiving tank 38 is connected to the elevated water tank 31 via a raw water supply line 39 in which a pump 40 is inserted. ing.

Since the water in the elevated water tank 31 is deaerated while circulating through the deaeration line 35, when the amount of water supplied to the building water supply system is reduced, the water in the elevated water tank 31 is reduced. The degree of deaeration of water is increased by excessive circulation, and the amount of dissolved gas exhausted by the deaerator 34 is reduced. Therefore, degassing by excessively circulating degassed water is a problem in energy saving.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to improve the energy saving effect of a deaerator in view of the above problems.

[0005]

Means for Solving the Problems The present invention has been made to solve the above-mentioned problems, and the invention according to claim 1 has a structure in which a degassing means and a vacuum pump are connected via a vacuum suction line. A deaerator for connecting and supplying a deaerated liquid to a supply line of the deaerator, wherein the vacuum pump deaerates the deaerated liquid in the deaerator by the vacuum pump. A pressure sensor for detecting a vacuum pressure in the air means or the vacuum suction line is provided, and an air introduction means is provided in the vacuum suction line, and the air introduction means, the pressure sensor, the pump and the vacuum pump are signaled. The invention is further characterized in that the degassing means and the vacuum pump are connected via a vacuum suction line, and the degassing is performed by the vacuum pump. hand A method for operating a deaerator configured to vacuum deaerate the liquid to be degassed in the vacuum pump, wherein a vacuum pressure in the deaerator or the vacuum suction line is detected, and the vacuum pump is operated based on the detected value. Controlling the number of rotations, controlling the amount of air introduced into the vacuum suction line, and controlling the supply amount of the liquid to be degassed to be supplied into the deaeration means. The invention described in the above description is characterized in that the control of the supply amount of the liquid to be degassed is performed by controlling the number of revolutions of a pump that supplies the liquid to be degassed. When the detected value reaches a preset lower limit pressure value, the vacuum pump and the pump are switched from high-speed operation to low-speed operation, and predetermined air is introduced into the vacuum suction line. Set upper limit pressure When it reaches the,
6. The method according to claim 5, wherein the vacuum pump and the pump are switched from a low-speed operation to a high-speed operation, and the introduction of air into the vacuum suction line is stopped.
The invention described in (1) is characterized in that a predetermined time difference is provided between the introduction and stop of the air into the vacuum suction line and the switching between high and low speed operation of the vacuum pump. Is characterized in that the number of revolutions of the pump during low-speed operation is controlled based on a changing speed at which a vacuum pressure between the lower limit pressure value and the upper limit pressure value changes per unit time.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of the present invention will be described. The present invention is realized in, for example, a deaerator installed as a measure for preventing red water in a building water supply system or the like. This deaerator is provided with a deaerator (for example, a membrane deaerator formed by a gas permeable membrane such as a hollow fiber membrane) provided with a water supply line having a pump for supplying a deaerated liquid and a discharge line for the deaerated liquid. A vacuum pump (for example, a water-sealed vacuum pump) is connected to the module) via a vacuum suction line, and a pressure sensor for detecting a vacuum pressure is provided on the deaeration means side of the vacuum suction line. An air introduction valve as air introduction means is provided on the side, and the vacuum pump, the pressure sensor, the air introduction valve, and the pump are connected to a controller via signal lines, respectively. Further, the deaeration means may be, for example, a deaeration tower system, and a pressure sensor for detecting a vacuum pressure may be provided in the deaeration tower.

[0007] According to the method of operating the deaerator having the above structure,
The pressure sensor detects a vacuum pressure in the vacuum suction line, and the detected value is a predetermined lower limit pressure (for example, 4
0 torr), the vacuum pump and the pump are switched from high-speed operation to low-speed operation (for example, 60 Hz → 20 Hz by inverter control) to introduce predetermined air into the vacuum suction line and supply the air to the deaeration means. The supply amount of the liquid to be degassed is reduced. When the detected value reaches a preset upper limit pressure value (for example, 80 torr), the vacuum pump and the pump are operated from a low speed operation to a high speed operation (for example, 20 Hz by inverter control).
(→ 60 Hz), the introduction of air into the vacuum suction line is stopped, and the supply amount of the liquid to be degassed to be supplied to the deaeration means is increased. The control of the rotation speed of the vacuum pump and the pump and the opening and closing of the air introduction valve are performed by control signals of the controller based on detection signals of the pressure sensor. The rotation speeds of the two pumps are controlled by an inverter built in the controller.

In the operating method, it is preferable that a predetermined time difference is provided as an operation confirmation time when introducing and stopping air into the vacuum suction line and when switching between high and low speed operation of the vacuum pump. is there. The setting of the time difference is performed by a timer built in the controller.

As described above, according to the operating method of the present invention, the vacuum pressure in the deaeration means or the vacuum suction line is detected, and the rotational speeds of the two pumps are controlled based on the detected value. As a result, the power consumption of the two pumps can be significantly reduced. Further, when the vacuum pump is operated at a low speed, by introducing an appropriate amount of air into the vacuum suction line, it is possible to prevent generation of noise in a transient state. In the case of high-speed operation, by stopping the introduction of the air, the vacuum pump becomes a rated operation, and the vacuum pressure in the deaerator can be lowered to the lower limit. Furthermore, when the vacuum pump operates at a low speed, the supply amount of the liquid to be degassed to be supplied to the deaeration means is also reduced at the same time, so that the deaeration degree of the deaeration liquid does not change.

Next, another operation method of the present invention will be described. The number of revolutions of the pump during low-speed operation is changed by changing the vacuum pressure between the lower limit pressure value and the upper limit pressure value per unit time. (For example, if the change in the degree of vacuum per minute is 10 Torr or less, the operation is switched to low speed, and if it is 10 Torr or more, the operation is switched to high speed operation). According to this operation method, it is possible to immediately respond when the amount of water supply requested by the load side becomes larger than usual. The set time and the calculation in the operation method are performed by a timer and a calculation means built in the controller.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is an explanatory view schematically showing a first embodiment of the present invention.

FIG. 1 schematically illustrates the structure of a deaerator according to the present invention. In the first embodiment, the present invention is applied to, for example, a building water supply system or the like. The deaerated liquid is circulated into predetermined deaerated water, and the deaerated water is supplied to the load side (not shown) via the water supply line 2. This is an embodiment of a deaerator configured as a deaerator 3 of the above deaerator with a membrane deaerator module 4 formed of a gas permeable membrane such as a hollow fiber membrane. A supply line 5 having a pump 18 for circulating the liquid to be deaerated is connected to one side of the membrane deaeration module 4. The other end of the supply line 5 is connected to the water storage tank 1. I have. The pump 18 is connected to the signal line 1
5 is connected to the controller 16. On the other hand, the other side of the membrane degassing module 4 is connected to a discharge line 6 for taking out degassed liquid, and this discharge line 6 is also connected to the water storage tank 1 to form a circulation line.

As a means for vacuum degassing the inside of the membrane degassing module 4, there is, for example, a water ring type vacuum pump 7,
As a general configuration of the vacuum pump 7, a water sealing line 8
And an exhaust line 9. The vacuum pump 7 and the membrane degassing module 4 are connected by a vacuum suction line 10, and a pressure sensor 11 for detecting a vacuum pressure in the membrane degassing module 4 is provided on the vacuum suction line 10. I have. As the pressure sensor 11, a semiconductor pressure sensor configured so that the pressure range can be set in a stepless manner is suitable.

The vacuum suction line 10 includes an automatic valve 12 such as an electromagnetic valve for starting and stopping a vacuum suction operation in the membrane degassing module 4, a check valve 13, and air as air introduction means. An introduction valve 14 is provided. The pressure sensor 11, the automatic valve 12, the air introduction valve 14
The vacuum pump 7 is connected to a controller 16 via a signal line 15, respectively. This controller 16
Includes an inverter (not shown) for controlling the rotation speed of the vacuum pump 7 and the pump 18 based on the detection signal of the pressure sensor 11, a timer (not shown), and a calculating means (not shown).

Here, the vacuum pressure in the membrane degassing module 4 and the degree of degassing of the liquid to be degassed (dissolved acidity concentration, ie, DO
2 is shown in FIG. 2, for example, when tap water is used as the liquid to be degassed. In FIG. 2, when the initial dissolved oxygen concentration of the tap water is set to 8 ppm and the predetermined dissolved oxygen concentration after deaeration of the tap water is set to 0.5 ppm, the vacuum pressure in the membrane degassing module 4 is set to about 40 torr.
It may be set to ~ 80 torr. That is, the lower limit of the vacuum pressure in the membrane degassing module 4 is set to 40 torr, and the upper limit is set to 80 torr.

Next, the operation method of the present invention will be described. In this operation method, the pressure sensor 11 detects the vacuum pressure in the vacuum suction line 10, and when the detected value reaches the lower limit pressure value of 40 torr, the rotation speed of the vacuum pump 7 and the pump 18 is changed from the high-speed operation. Low speed operation (60Hz
(→ 20 Hz) through the controller 16 to reduce the supply amount of the liquid to be degassed to be supplied to the membrane deaeration module 4, open the air introduction valve 14 and supply air to the vacuum suction line 10. Introduce. When the detected value reaches the upper limit pressure value of 80 torr, the rotation speed of the vacuum pump 7 and the pump 18 is changed from the low speed operation to the high speed operation (20
Hz → 60 Hz) and the membrane degassing module 4
The supply amount of the liquid to be deaerated to be supplied to the vacuum suction line is increased, the air introduction valve 14 is closed, and the introduction of air into the vacuum suction line 10 is stopped. Further, the vacuum suction line 10
Introduction and stop of air to the vacuum pump 7
A predetermined time difference is provided when the low-speed operation is switched (see FIGS. 3 and 4).

According to the operating method, the vacuum pressure in the vacuum suction line 10 is detected, and the rotation speeds of the vacuum pump 7 and the pump 18 are controlled based on the detected value. The power consumption of the pump 7 and the pump 18 can be significantly reduced. That is, since the power consumption of the vacuum pump 7 and the pump 18 is proportional to the cube of the rotation speed, the rotation speed is reduced from 60 Hz to around the lower limit rotation speed of 20 Hz. Therefore, the power consumption during low-speed operation is about 3.6% of that during high-speed operation.
Therefore, the energy saving effect is great.

Further, when the vacuum pump 7 is operated at a low speed, an appropriate amount of air is introduced into the vacuum suction line 10 to prevent generation of noise in a transient state. Since the introduction of the air is stopped, the vacuum pump 7 is in rated operation, and the vacuum pressure in the membrane degassing module 4 can be reduced to the lower limit.
Since a time difference is provided between the opening / closing operation of the air introduction valve 14 and the start timing of the change in the number of revolutions of the vacuum pump 7, each operation check time is set, so that more effective control is performed. can do. Further, when the vacuum pump 7 is operated at a low speed, the supply amount of the deaerated liquid supplied to the membrane deaeration module 4 is simultaneously reduced, so that the deaeration degree of the deaerated liquid is changed. Therefore, there is an effect of stabilizing the degree of deaeration of the deaerated water in the water storage tank 1.

Next, a second embodiment of the present invention will be described with reference to FIG. In the second embodiment, the deaerator 3 of the deaerator described in the first embodiment is changed from a membrane deaerator module 4 to a mechanical deaerator 17. Members other than those described above are denoted by the same reference numerals as in the first embodiment, and redundant description will be omitted.

FIG. 5 is an explanatory view schematically showing the structure of the deaerator of the second embodiment. In FIG. 5, a degassing tower 17 applied as a degassing means 3 is provided, a supply line 5 having a pump 18 for circulating a liquid to be degassed is connected to the upper part of the degassing tower 17, and a spray nozzle is provided at the tip. 5a is provided, and the other end is connected to the water storage tank 1. In addition, the degassing tower 17
A discharge line 6 for taking out the degassed liquid is connected to a lower part of the tank, and this discharge line 6 is also connected to the water storage tank 1 to form a circulation line. And the pump 18
It is connected to a controller 16 via a signal line 15.

As means for vacuum degassing the inside of the degassing tower 17, for example, a water ring type vacuum pump 7 is provided, and the vacuum pump 7 and the upper part of the degassing tower 17 are connected by a vacuum suction line 10. doing. In the degassing tower 17,
A pressure sensor 11 for detecting a vacuum pressure in the degassing tower 17 is provided below the portion to which the vacuum suction line 10 is connected. The vacuum suction line 10 includes:
An automatic valve 12 such as a solenoid valve, a check valve 13, and an air introduction valve 14 as air introduction means are provided. The pressure sensor 11, the automatic valve 12, the air introduction valve 14, and the vacuum pump 7 are connected to the controller 16 via signal lines 15, respectively. The controller 16 includes:
As in the first embodiment, control such as rotation speed control of the vacuum pump 7 and the pump 18 is performed based on the detection signal of the pressure sensor 11.

Another embodiment of the operating method of the present invention will be described. That is, the rotation speed of the pump 18 for supplying the liquid to be degassed at the time of low speed operation, the vacuum pressure in the deaeration means 3 or the vacuum suction line 10 depends on the lower pressure value 40 torr and the upper pressure value 80 torr.
(For example, if the change in the degree of vacuum is 10 torr or less per minute, the operation is set to low speed, and the control is performed based on the rate of change of the vacuum pressure per unit time).
If it exceeds torr, switch to high-speed operation. ). According to this operation method, it is possible to immediately respond when the amount of water supplied by the load side becomes larger than usual. The set time and calculation in this operation method are performed by a timer and a calculation means built in the controller 16.

[0023]

As described above, according to the present invention, a pressure sensor for detecting a vacuum pressure in a degassing means or a vacuum suction line is provided, and a vacuum pump is provided based on the detected value of the pressure sensor. Since the number of rotations of the pump for supplying the liquid to be degassed to the degassing means is controlled, the power consumption of both pumps can be significantly reduced. Also,
Since the air introduction means is provided in the vacuum suction line, generation of noise in a transient state can be prevented.

[Brief description of the drawings]

FIG. 1 is an explanatory view schematically showing a configuration of a first embodiment of a deaerator according to the present invention.

FIG. 2 is an explanatory diagram showing a relationship between a vacuum pressure and a DO value in the membrane degassing module of FIG.

FIG. 3 is an explanatory diagram showing an operation range in which the number of rotations of a vacuum pump is controlled by a detection signal of a pressure sensor of FIG. 1;

FIG. 4 is an explanatory diagram showing a state in which a time difference is provided in the operation region of FIG. 3 to open and close the air introduction valve.

FIG. 5 is an explanatory view schematically showing a configuration of a second embodiment of the deaerator according to the present invention.

FIG. 6 is a schematic explanatory view showing a state in which a conventional deaerator is installed in a building water supply system.

[Explanation of symbols]

 Reference Signs List 3 Deaeration means 4 Membrane deaeration module 5 Supply line 6 Discharge line 7 Vacuum pump 10 Vacuum suction line 11 Pressure sensor 14 Air introduction valve (air introduction means) 15 Signal line 16 Controller 17 Deaeration tower 18 Pump

Claims (6)

[Claims] 1. A deaerator for connecting the deaeration means 3 and a vacuum pump 7 via a vacuum suction line 10 to vacuum deaerate the liquid to be deaerated in the deaeration means 3 by the vacuum pump 7. A pump 18 for supplying a liquid to be degassed to the supply line 5 of the degassing means 3 is provided, and a pressure sensor 11 for detecting a vacuum pressure in the degassing means 3 or the vacuum suction line 10 is provided.
And an air introducing means 14 is provided in the vacuum suction line 10, and the air introducing means 14, the pressure sensor 11, the pump 18 and the vacuum pump 7 are connected to a controller 16 via a signal line 15. A degassing device characterized by the following. 2. A deaeration device in which the deaeration means 3 and the vacuum pump 7 are connected via a vacuum suction line 10, and the deaerated liquid in the deaeration means 3 is vacuum deaerated by the vacuum pump 7. An operation method of the apparatus, wherein a vacuum pressure in the deaeration means 3 or the vacuum suction line 10 is detected, and a rotation speed of the vacuum pump 7 is controlled based on the detected value. A method for operating a degassing apparatus, characterized in that the amount of air introduced into the degassing means (10) is controlled and the amount of degassed liquid supplied to the degassing means (3) is controlled. 3. The degassing apparatus according to claim 2, wherein the control of the supply amount of the liquid to be degassed is performed by controlling the rotation speed of a pump 18 that supplies the liquid to be degassed. Driving method. 4. The vacuum pump 7 and the pump 18 when the detected value reaches a preset lower limit pressure value.
Is switched from high-speed operation to low-speed operation, predetermined air is introduced into the vacuum suction line 10, and when the detected value reaches a preset upper limit pressure value, the vacuum pump 7 and the pump 18 are operated at low speed. The method for operating the deaerator according to claim 3, wherein the operation is switched from a high-speed operation to a high-speed operation, and the introduction of air into the vacuum suction line 10 is stopped. 5. The deaeration according to claim 4, wherein a predetermined time difference is provided between the introduction and stop of the air to the vacuum suction line and the switching between the high and low speed operation of the vacuum pump. How to operate the device. 6. The system according to claim 1, wherein the number of revolutions of the pump during low-speed operation is controlled based on a change speed at which a vacuum pressure between the lower limit pressure value and the upper limit pressure value changes per unit time. The operation method of the deaerator according to claim 4, wherein