JPH07709A - Deaerator - Google Patents

Abstract

PURPOSE:To curtail installation cost and running cost and to save steam con sumption. CONSTITUTION:Feed raw water is fed to a condenser 51, and steam of deaerated gas sucked from a membrane separator 32 by a vacuum pump 33 is condensed by using the feed raw water as a cooling medium and discharged to outside the condenser 51. Next, the feed raw water is sent to a heat exchanger 53 and heated up by using the feed raw water after deaeration discharged from the membrane separator 32 (deaerated water) as a heating medium, and then the feed raw water is sent to a steam heater 55 and further heated up by using heating steam as a heating medium. Next, the feed raw water after heating-up is sent to the membrane separator 32 and passed through a porous membrane to allow the low pressure deaeration of gas, such as air dissolved in the feed raw water. At this time, a steam flow control valve 63 installed in a heating steam supply system is controlled by a temp. controller 62 to keep constant the temp. of the feed raw water going toward the membrane separator 32 from the steam heater 55.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a degassing device for degassing gas such as air dissolved in raw water for supply.

[0002]

2. Description of the Related Art In producing a soft drink, a deaerator is used to deaerate gas such as air dissolved in a liquid. An example of a conventional deaerator (Japanese Patent Publication No. 1-116
2 and 3 are shown in FIGS. 2 and 3, and another example of the conventional deaerator (as described in Japanese Patent Application No. 2-255211) is shown in FIGS. 4 and 5. .

First, the deaerator shown in FIGS. 2 and 3 will be described.
In FIG. 2, 1 is a supply raw water supply port, 2 is a flow rate adjusting automatic valve, 3 is a three-way switching automatic valve, 4 is a tank lid, 5 is an ejection nozzle provided on the tank lid 4, 6 is a deaeration tank, and the ejection is performed. Nozzle 5
Ejects the supplied raw water to the liquid surface of the supplied raw water in the degassing tank 6. 6 is a degassing tank, 7 is a vacuum gauge for detecting the degree of vacuum in the degassing tank 6, 8 is a tank viewing window, 9 is a liquid level control device, 10 is a cleaning pipe, 10a is a tank cleaning spray,
The three-way switching automatic valve 3 supplies the supplied raw water to the jet nozzle 5 attached to the tank lid 4 during a normal degassing process operation, and supplies the cleaning water when the degassing tank 6 is cleaned. It is supplied to the tank cleaning spray 10a from the mouth 1 through the cleaning pipe 10.

Reference numeral 11 is a vacuuming device, 12 is a vacuuming pipe, 1
Reference numeral 3 is a check valve, and the vacuuming device 11 holds the inside of the degassing tank 6 at a predetermined vacuum degree to degas low-pressure gas such as air dissolved in the raw feed water, while degassing the same. The gas and vapor are discharged to the outside of the deaerator through the check valve 13 → vacuum drawing pipe 12. Reference numeral 14 denotes a liquid feed pump, and the liquid level of the raw feed water in the degassing tank 6 changes depending on the amount of degassed water sent to the next step by the liquid feed pump 14. At this time, the liquid level control device 9 controls the flow rate adjusting automatic valve 2 to keep the liquid level of the raw feed water in the degassing tank 6 constant.

Reference numeral 15 is a treated water outlet (exhaust feed water outlet after deaeration), 16 is a bypass pipe, 17 is a bypass automatic valve which is automatically opened when the liquid feed pump 14 starts operating, 18 is a check valve, and 19 is a check valve. Is a drain valve, and the bypass pipe 16 uses a part of the degassed water sucked by the liquid feed pump 14 to bypass the automatic valve 17 → the primary side of the jet nozzle 5 → in the degassing tank 6 →
It is circulated to the liquid feed pump 14.

The conventional deaerator shown in FIG. 2 has the structure shown in FIG.
As shown in FIG. 5, the raw feed water is jetted from the inlet 20 of the jet nozzle 5 to the outlet 21 to the raw raw water 26 stored in the degassing tank 6 in the vacuum atmosphere 22 into the liquid column 23 by the pressure difference between the raw raw water supply pressure and the vacuum pressure. To do. At this time, the upper layer portion of the raw feed water 26 stored in the degassing tank 6 is violently hit by the fluid kinetic energy of the raw feed water to generate bubbles 24 in the upper layer portion and also violently disturb the upper layer portion.

The bubbles 24 are composed of degassed gas separated from the feed raw water and vapor of the feed raw water, and the composition of the bubbles 24 is approximately equal to the composition of the gas in the vacuum atmosphere 22 in the degassing tank 6. The bubbles 24 are generated one after another. Then, while being mixed with each other, the raw feed water 26 rises while being stirred, and is discharged into the vacuum atmosphere 22.
And is degassed.

Next, the conventional deaerator shown in FIGS. 4 and 5 will be described. In FIG. 4, 31 is a feed raw water feed pump, 32 is a membrane separator, and 33 is a vacuum pump. Further, in FIG. 5 which is an enlarged view of the portion A of the membrane separation device 32 of FIG. 4, 40 is a large number of porous hollow fibers made of polypropylene, polytetrafluoroethylene or the like.
Are bundled, each having an inner diameter of 100 μm to 300 μm
It has a minute fluid flow path 41.

In the conventional deaerator shown in FIGS. 4 and 5, the raw raw water 42 sent to the membrane separation device 32 by the raw raw water supply pump 31 is supplied to each porous hollow fiber 40 by 5 to 5.
The gas dissolved in the raw feed water 42 is sucked into the fine fluid flow path 41 of each porous hollow fiber 40 to the vacuum pump 33 to flow the gas, which is flowed at a flow rate of about 20 m / sec, for degassing.

[0010]

The conventional deaerator shown in FIGS. 2 and 3 requires control means for making the injection amount into the raw raw water constant, and the liquid feed pump 14 has N
Liquid pump 1 that requires a special pump with low PSH _R
In order to prevent inhalation of air from the mechanical seal part of 4, it is necessary to inject seal water, which complicates the structure and requires the provision of control means and peripheral auxiliary equipment, resulting in equipment cost. In addition to being bulky, the deaerator becomes larger,
There was a problem that a large installation space was required.

The conventional deaerator shown in FIG. 4 and FIG.
The deaeration tank 6, the control means, and the liquid feed pump 14 shown in FIGS.
Since the deaerator can be downsized, the installation space can be saved, and the cost can be reduced. Further, the CIP cleaning time can be shortened, and even if the feed amount of the supplied raw water changes, there is an advantage that the adjustment is not required and the operation is easy. However, the fluid flow passage 41 of the porous hollow fiber 40 has gas O ₂ , N Since it is a fine hole with an inner diameter of about 100 μm to 300 μm that allows gas such as ₂ to pass through but does not allow liquid to pass through, it has a limited degassing capacity, and when a large capacity degassing device is required, the membrane separation device 32 becomes larger. In addition, a vacuum pump 33 for sucking air in the membrane separation device 32
Becomes larger. In addition, the porous hollow fiber 40 is expensive,
There was a problem that equipment costs increased.

The present invention is proposed in view of the above problems, and the object of the present invention is to reduce equipment costs and running costs. Another point is to provide a deaerator capable of reducing the steam consumption.

[0013]

In order to achieve the above-mentioned object, the deaerator of the present invention is an air which is dissolved in the feed raw water after the feed raw water after the temperature rise is passed through the porous membrane. A membrane separator for low-pressure degassing of gas such as the above, a condenser for condensing water vapor of the degassed gas sucked from the above-mentioned membrane separator by a vacuum pump using the raw water supplied to the degasser as a refrigerant, and the above-mentioned membrane separation A heat exchanger for raising the temperature of the feed raw water discharged from the condenser using the degassed feed raw water discharged from the device as a heat medium, and a feed raw water discharged from the heat exchanger using the heating steam as a heat medium are further added. A steam heater for raising the temperature, and a temperature control device for controlling the steam flow rate control valve provided in the heating steam supply system to keep the temperature of the raw feed water flowing from the steam heater to the membrane separation device constant. .

[0014]

The deaerator of the present invention is configured as described above, and supplies the raw feed water to the condenser and condenses the vapor of the degassed gas sucked by the vacuum pump from the membrane separation device using the raw feed water as a refrigerant. And discharge it to the outside of the condenser.
Next, the feed raw water is sent to the heat exchanger, the feed raw water after degassing discharged from the membrane separation device (degassed water) is used as a heat medium to raise the temperature of the feed raw water, and then the feed raw water is sent to the steam heater, Use the heated steam as a heat medium to further raise the temperature of the raw water supplied,
Next, the feed raw water whose temperature has been raised is sent to a membrane separation device and passed through a porous membrane to degas low-pressure gas such as air dissolved in the feed raw water. At this time, the temperature control device controls the steam flow rate control valve provided in the heating steam supply system to keep the temperature of the raw feed water from the steam heater toward the membrane separation device constant.

[0015]

EXAMPLE Next, the deaerator of the present invention will be explained with reference to an example shown in FIG. 1. In the figure, 51 is a condenser, and the condenser 51 uses the raw water supplied to the deaerator as a refrigerant.
The degassed water vapor sucked from the membrane separation device 32 to the pipe 68 of the condenser 51 → the separator 69 → the vacuum pump 33 is condensed, and the condensed water is discharged to the outside of the separator 69 (see drain).

Reference numeral 53 denotes a heat exchanger, which heats the degassed feed raw water (degassed water) discharged to the membrane separator 32 → the pipe 57 of the heat exchanger 53 → the pipe 58. As the heat medium, the temperature of the raw water supplied to the condenser 51, the pipe 52, and the heat exchanger 53 is raised. 55 is a steam heater, and the steam heater 55 uses a heating steam flowing in a heating steam supply system of a pressure adjusting valve (pressure reducing adjusting valve) 64 → steam flow control valve 63 → pipe 61 → pipe 65 → trap 66 as a heat medium, While the temperature of the raw water to be fed to the inside of the heat exchanger 53 → the pipe 54 → the inside of the steam heater 55 is further raised, the condensed heated steam after heat exchange is discharged to the outside of the trap 66 (see drain).

Reference numeral 32 is a membrane separation device similar to the membrane separation device shown in FIGS. 4 and 5, and the membrane separation device 32 includes the vapor heater 5
The gas such as air dissolved in the raw raw water is decompressed at a low pressure by passing the raw raw water after being heated, which is sent to the inside of the pipe 5, the pipe 56, and the membrane separation device 32 through the porous membrane. Then, the degassed gas is sucked out by the system of the membrane separation device 32 → the pipe 68 of the condenser 51 → the separator 69 → the vacuum pump 33, and the raw water after degassing (degassed water) is the membrane separation device 32 → the heat exchanger 53. Pipe 57 → Pipe 58 → Discharge to the next step.

Reference numeral 62 denotes a temperature control device (temperature indicating regulator) provided in the pipe 56. The temperature control device 62 detects the temperature of the feed raw water that has flown through the pipe 56 and has been heated. A signal is sent to the steam flow control valve 63, and the steam flow control valve 63 is controlled (the steam flow is controlled) to keep the temperature of the raw feed water from the steam heater 55 toward the membrane separation device 32 constant. Has become.

Next, the operation of the deaerator shown in FIG. 1 will be specifically described. The supplied raw water is supplied to the condenser 51, and the supplied raw water is used as a refrigerant to condense the steam of the degassed gas sucked from the membrane separation device 32 to the pipe 68 of the condenser 51 → separator 69 → the vacuum pump 33 to form the condenser 5
1 Discharge as drain. Next, using the raw water after degassing (degassed water) discharged from the membrane separation device 32 to the pipe 57 of the heat exchanger 53 to the pipe 58 as a heat medium, to the condenser 51 → the pipe 52 → into the heat exchanger 53. While raising the temperature of the feed raw water to be sent, the feed raw water after deaeration (deaerated treated water) whose temperature has dropped due to this heat exchange is sent from the pipe 58 to the next step.

Next, the pressure adjusting valve (pressure reducing adjusting valve) 64 → steam flow control valve 63 → pipe 61 → pipe 65 → trap 66
Using the heating steam flowing in the heating steam supply system as a heat medium, the temperature of the supply raw water sent to the inside of the heat exchanger 53 → the piping 54 → the steam heater 55 is further raised (the temperature is raised to about 40 to 60 ° C.), while the heat Trap 6 for condensed heated steam after replacement
6 Discharge as drain to the outside.

Next, the feed raw water after being heated is sent to the pipe 56 → membrane separation device 32 and passed through the porous membrane to degas low-pressure gas such as air dissolved in the feed raw water.
At this time, the temperature control device (temperature instruction adjuster) 62 detects the temperature of the raw feed water that has flown through the pipe 56 and sends a temperature detection signal obtained at that time to the steam flow control valve 63 to control the steam flow. By controlling the valve 63 (controlling the steam flow rate), the temperature of the raw feed water flowing from the steam heater 55 toward the membrane separation device 32 is kept constant.

Since the feed raw water sent to the membrane separation device 32 is heated, the gases such as O ₂ and N ₂ contained in the feed raw water are more activated than at room temperature, The ability of the porous membrane to pass through the micropores is increased by a factor of 2-3.

[0023]

As described above, the deaerator of the present invention raises the temperature of the raw water supplied to the membrane separation device, and the gas such as O ₂ and N ₂ contained in the raw water supplied is higher than at room temperature. Since it is also activated, the ability to pass through the micropores of the porous membrane can be increased to 2-3 times, and the membrane separation column can be miniaturized. In addition, since the water vapor evaporated and separated by the membrane separation column is condensed and liquefied by the condenser, the suction load of the vacuum pump can be reduced, the vacuum pump can be downsized, and the membrane separation column can be downsized, which leads to equipment costs. It can be reduced.

Further, while the raw raw water before deaeration is used as the refrigerant of the condenser, the raw raw water after deaeration (deaerated treated water) is used as the heat medium of the heat exchanger, so that the heat can be sufficiently recovered. Therefore, the running cost of the deaerator can be reduced. Further, in the steam heater, since it is sufficient to heat only the insufficient temperature rise of the raw feed water that has been warmed in the previous stage and before degassing, the temperature control device controls the steam flow control valve provided in the heating steam supply system, The amount of steam consumed can be reduced in combination with the fact that the temperature of the raw water supplied from the steam heater to the membrane separator is kept constant.

[Brief description of drawings]

FIG. 1 is a system diagram showing an embodiment of a deaerator of the present invention.

FIG. 2 is a vertical sectional side view showing an example of a conventional deaerator.

FIG. 3 is an explanatory view of the operation of the deaerator.

FIG. 4 is a side view showing another example of a conventional degassing device.

5 is an enlarged vertical side view of a portion indicated by an arrow A in FIG.

[Explanation of symbols]

 32 membrane separator 33 vacuum pump 51 condenser 53 heat exchanger 55 steam heater 62 temperature controller 63 steam flow control valve

Claims (1)

[Claims] 1. A membrane separation device for degassing a gas such as air dissolved in the raw raw water by low pressure by passing the raw raw water after heating through a porous membrane, and a supply supplied to the degassing device. A condenser that condenses water vapor of a degassed gas sucked by a vacuum pump from the membrane separation device using raw water as a refrigerant,
A heat exchanger that raises the temperature of the feed raw water discharged from the condenser using the degassed feed raw water discharged from the membrane separator as a heat medium, and a supply discharged from the heat exchanger using heated steam as a heat medium. A steam heater for further raising the temperature of the raw water, and a temperature control device for controlling the steam flow rate control valve provided in the heating steam supply system to keep the temperature of the raw water from the steam heater toward the membrane separation device constant. A deaerator characterized by being equipped with.