JPH05103907A - Piping construction of water seal vacuum pump in deaerator - Google Patents

Abstract

PURPOSE:To surely obtain high vacuum by simple constitution without causing increase in cost in deaerators. CONSTITUTION:A deaeration module 1 is connected to a high vacuum side water seal vacuum pump 2 for vacuum sucking of a dissolved gas in raw water through the deaeration module and, simultaneously, the high vacuum side water seal vacuum pump 2 is connected to a low vacuum side water seal vacuum pump 4 in series. The exhaust line 3 of the high vacuum side water seal vacuum pump 2 communicates with the suction opening 5 of the low vacuum side water seal vacuum pump 4 to arrange the high vacuum side water seal vacuum pump 2 at a position higher than the low vacuum side water seal vacuum pump 4, causing the vacuum of the high vacuum side water seal vacuum pump 2 to be increased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION This invention relates to a deaerator,
The present invention relates to a device for the arrangement structure of water-sealed vacuum pumps connected in series.

[0002]

2. Description of the Related Art In recent years, with the mass production of gas permeable membranes (hydrophobic polymer membranes) that allow only gas to pass through without passing through water, this gas permeable membrane is used to reduce the pressure of dissolved gas in water through the membrane. Membrane-type degassing equipment that deposits in the lower gas phase has been put to practical use.
The membrane deaerator has features such as a compact device configuration, low running cost, and high safety.

[0003]

When the dissolved oxygen in the raw water is vacuumed by the membrane type deaerator, an inexpensive water-sealed type vacuum pump is often used. Generally, the vacuum pump operates at a constant compression ratio regardless of the vacuum pressure. For example, a vacuum pump with a compression ratio of 50 is 15 torr.
To compression work up to 750 torr. If the pressure loss at the pump outlet is 2 torr, the exhaust pressure is 752 torr, and the obtained vacuum pressure is 15.04 t.
The calculation is orr. Therefore, the deterioration of the vacuum pressure is about 0.2%. In the case of the above-described multi-stage degassing device, the influence of the pressure loss at the pump outlet is negligible in the low vacuum side vacuum pump in the front stage, but is extremely large in the high vacuum side vacuum pump in the rear stage. In particular, the water-sealed vacuum pump discharges the sealed water together with the gas, which causes a large pressure loss.

Assuming that the high vacuum side vacuum pump performs compression work from 0.1 torr to 5 torr, the exhaust pressure is 7 torr if the pressure loss at the pump outlet is 2 torr.
And the obtained vacuum pressure is calculated to be 0.14 torr. Therefore, the vacuum pressure is deteriorated by about 40%. As a countermeasure for this, a method of increasing the diameter of the exhaust pipe to suppress the pressure loss as much as possible is taken, but this is a factor that causes an increase in cost.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and is intended to surely obtain a high degree of vacuum with a simple structure without causing an increase in cost. Yes, specifically, a high-vacuum-side water-sealed vacuum pump that vacuum-dissolves dissolved gas in raw water through the degassing module is connected to the deaeration module, and the high-vacuum-side water-sealed vacuum pump is connected to the low-vacuum side vacuum pump. Connect the vacuum side water-sealed vacuum pump in series, and connect the discharge line of the high vacuum side water-sealed vacuum pump to the intake port of the low vacuum side water-sealed vacuum pump to connect the high vacuum side water-sealed vacuum pump. It is characterized in that it is placed higher than the water-sealed vacuum pump on the low vacuum side.

[0006]

According to the above structure, the discharge line of the high vacuum side water-sealed vacuum pump is connected to the intake port of the low vacuum side water-sealed vacuum pump, and the high vacuum side water-sealed vacuum pump is connected to the low vacuum side. Since it is located higher than the water-sealed vacuum pump,
Due to the action of gravity, it is possible to minimize the pressure loss at the outlet of the high vacuum side water-sealed vacuum pump, and the high vacuum side water-sealed vacuum pump is equal to the height difference between the two. The degree of vacuum can be increased.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings. In the embodiment shown in FIG. 1, (1) is a degassing module, which is constructed by using, for example, a gas permeable membrane. 7) are connected to each other, and the dissolved gas in the raw water is vacuum-sucked through the gas permeable membrane while the raw water is passing through the degassing module. The degassing module (1) may be a mechanical one such as a degassing tower, in addition to the above-mentioned one using the gas permeable membrane.

(2) and (4) are water-sealed vacuum pumps, in which the high-vacuum side water-sealed vacuum pump (2) is connected to the degassing module (1) through a vacuum degassing line (8). ing. The discharge line (3) of the high vacuum side water-sealed vacuum pump (2) is connected to the intake port (5) of the low vacuum side water-sealed vacuum pump (4),
Both water-sealed vacuum pumps are connected in series. Also, replace the high vacuum side water-sealed vacuum pump (2) with the low vacuum side water-sealed vacuum pump.
(4) It is placed at a height higher than the height H. (9) is a seal water supply line for supplying seal water to the high vacuum side water seal vacuum pump (2).

Next, the operation will be described. The raw water supplied from the raw water supply line (6) is passed through the degassing module (1) by the high vacuum side water-sealed vacuum pump (2) and the low vacuum side water-sealed vacuum pump (4). Dissolved gas is vacuum-sucked into degassed water, which is sent from the treated water discharge line (7) to each degassed water equipment. In this degassing step, the higher the vacuum degree of the vacuum pump (the higher the vacuum state), the more the dissolved gas in the raw water can be removed to a lower dissolved concentration level.

In the present invention, the high vacuum side water-sealed vacuum pump
Connect the discharge line (3) of (2) to the low vacuum side water-sealed vacuum pump (4).
The high vacuum side water-sealed vacuum pump (2) is placed higher than the low vacuum side water-sealed vacuum pump (4) while communicating with the intake port (5) of the The pressure at the outlet of the vacuum side water-sealed vacuum pump (2) can be lowered. That is, since the discharge line (3) is almost filled with the discharged sealing water and air bubbles, the high vacuum side water sealing type vacuum pump (2) and the low vacuum side water sealing type vacuum pump. (Four)
The height difference H of the arrangement position, in other words, the pressure corresponding to the head difference (γH; γ is the apparent specific gravity of water containing air bubbles) of the high vacuum side water-sealed vacuum pump (2). The discharge pressure can be increased.

The embodiment shown in FIG. 2 shows an application example of the present invention in a multistage deaerator. (10), (1
1) is a degassing module, which is the first degassing module (10) and the second
The degassing module (11) is connected in series. Of these degassing modules, the first degassing module (1
The raw water supply line (6) is connected to one end of (0), and the treated water discharge line (7) is connected to one end of the second degassing module (11) on the rear stage side. ), And then into the second degassing module (11), and in the process, the dissolved gas in the raw water is vacuumed through these degassing modules.

Reference numeral (12) is a first water-sealed vacuum pump, which is connected to the first degassing module (10) through a first vacuum degassing line (16). Vacuum suction of dissolved gas in raw water through. (13) is a second water-sealed vacuum pump, which is connected to the second degassing module (11) through a second vacuum degassing line (17), and the raw water is passed through the second degassing module. Vacuum suction the dissolved gas. The discharge line (14) of the second water-sealed vacuum pump (13) is communicated with the intake port (15) of the first water-sealed vacuum pump (12), and both water-sealed vacuum pumps are connected in series. Connected to. Further, the second water-sealed vacuum pump (13) which is a high vacuum side vacuum pump is arranged at a height H higher than the first water-sealed vacuum pump (12) which is a low vacuum side vacuum pump. (18) is a sealing water supply line for supplying sealing water to the vacuum pump, and in the illustrated embodiment,
The seal water supply line (18) is connected to the second water seal vacuum pump (13), and the seal water used in this second water seal vacuum pump is passed through the discharge line (14) to the first water seal vacuum pump. Although it is sent to (12), another sealed water supply line can be connected to the first water sealed vacuum pump (12). Further, it is economical to return the sealed water discharged from the first water-sealed vacuum pump (12) to a sealed water tank (not shown) and circulate it.

Next, the operation of the above system will be described. The raw water supplied from the raw water supply line (6) is
While passing through the degassing module (10) and the second degassing module (11), the first water-sealed vacuum pump (12) and the second water-sealed vacuum pump (13) suck the dissolved gas under vacuum. Is converted to degassed water, and is sent to each equipment using degassed water from the treated water discharge line (7). In this deaeration process, the higher the vacuum pressure of the vacuum pump (the higher the vacuum state), the more the dissolved gas in the raw water can be removed to a lower dissolved concentration level.

In the present invention, the discharge line (14) of the second water-sealed vacuum pump is connected to the intake port (15) of the first water-sealed vacuum pump.
The second is a high vacuum side vacuum pump
The water-sealed vacuum pump (13) is the first vacuum pump on the low vacuum side.
Since it is located higher than the water-sealed vacuum pump (12),
Due to the action of gravity, the pressure at the outlet of the second water-sealed vacuum pump can be lowered. That is, since the discharge line (14) is almost filled with the discharged sealing water and bubbles, the first water sealing vacuum pump (12) and the second water sealing vacuum pump (13) ) The height difference H of the arrangement position, in other words, the pressure equivalent to the water head difference (γH; γ is the apparent specific gravity of water containing bubbles), the discharge pressure of the second water-sealed vacuum pump. Can be increased. The illustrated embodiment has two
The present invention is applicable to a multi-stage deaerator having three or more stages, although it is a multi-stage deaerator.

[0015]

The present invention has the above-mentioned structure.
Connect the high vacuum side water seal vacuum pump and the low vacuum side water seal vacuum pump to the degassing module, and connect the high vacuum side water seal vacuum pump discharge line to the low vacuum side water seal vacuum pump. In addition to communicating with the mouth, the high vacuum side water-sealed vacuum pump is placed higher than the low vacuum side water-sealed vacuum pump. The vacuum pressure increases by the difference in height between the positions where the two vacuum pumps are arranged, and the degree of vacuum on the suction side of the high vacuum side water-sealed vacuum pump can be correspondingly increased. or,
Since the present invention merely devises the arrangement structure of the water-sealed vacuum pump, it is possible to surely obtain a practically excellent effect with a simple structure and without increasing the manufacturing cost.

[Brief description of drawings]

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

FIG. 2 is a system diagram showing another embodiment of the present invention.

[Explanation of symbols]

 1 Deaeration module 2 High vacuum side water-sealed vacuum pump 3 Evacuation line 4 Low vacuum side water-sealed vacuum pump 5 Inlet 10 First deaeration module 11 Second deaeration module 12 First water-sealed vacuum pump 13th 2 Water-sealed vacuum pump 14 Discharge line 15 Intake port

Claims (2)

[Claims] 1. A degassing module (1) is connected with a high vacuum side water-sealed vacuum pump (2) for vacuum suction of dissolved gas in raw water through the degassing module, and the high vacuum side water-sealed type Vacuum pump (2) with low vacuum side water-sealed vacuum pump (4)
Connected in series to connect the discharge line (3) of the high vacuum side water-sealed vacuum pump (2) to the intake port (5) of the low vacuum side water-sealed vacuum pump (4), Arrangement structure of a water-sealed vacuum pump in a deaerator, wherein the water-sealed vacuum pump (2) is arranged at a higher position than the water-sealed vacuum pump (4) on the low vacuum side. 2. A first degassing module (10) and a second degassing module (11) are connected in series, and the first degassing module (1)
(1) is connected to a first water-sealed vacuum pump (12) for vacuum suction of dissolved gas in raw water through the degassing module, and the second degassing module (11) is passed through the degassing module to pass through the raw water. Second water-sealed vacuum pump that sucks dissolved gas of
3) is connected, and the discharge line (1) of the second water-sealed vacuum pump (13) is connected.
The second water-sealed vacuum pump, which is a high-vacuum side vacuum pump, by communicating 4) with the intake port (15) of the first water-sealed vacuum pump (12).
(13) is the first water-sealed vacuum pump which is a low vacuum side vacuum pump
(12) An arrangement structure of a water-sealed vacuum pump in a deaerator, which is arranged at a higher position.