JP2016112490A - Dissolved oxygen removal system and dissolved oxygen removal method for well water - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dissolved oxygen removal system and a dissolved oxygen removal method for well water which can prevent blocking of a structure in the well or in an aquifer due to dissolved oxygen of the well water.SOLUTION: A dissolved oxygen removal system 1A comprises: a well 2 having well water W and being flooded or pumped; a deaeration pipe 3 that one end 31 is inserted in the well 2; and a vacuum pump 4 connected to another end 32 of the deaeration pipe 3 and raising the well water W from the one end 31 into the deaeration pipe 3 to an appointed height h. When the vacuum pump 4 is operated, the well water W is raised from the one end 31 of the deaeration pipe 3 into the deaeration pipe 3, and the surface of the water in the deaeration pipe 3 stops at a height h equivalent to a head pressure depending on degree of decompression. the dissolved oxygen of the well water W is deaerated from the well water W with decompression.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a dissolved oxygen removal system and a dissolved oxygen removal method for well water.

  Conventionally, the groundwater level is changed by pouring or pumping water into a well. For example, in mountain retaining work, groundwater is pumped from a pumping well provided at an excavation site, and groundwater is returned to the soil from a water injection well (recharge well) provided at another location. In addition, since the flow of groundwater can be controlled by pouring or pumping water, water is poured or pumped for the purpose of purifying the contaminated area and preventing diffusion in the contaminated soil countermeasures.

  If water injection wells and pumping wells continue to be used, fine particles (fine particles, organic matter, microorganisms, etc.) contained in well water, and oxides (iron oxide, calcium oxide, etc.) formed by dissolved oxygen in well water, etc. Clogging occurs in the well structure and in the aquifer. When clogging occurs, it becomes difficult to perform water injection or pumping. Therefore, sometimes, clogging is eliminated by passing water in the opposite direction.

  A method for preventing clogging has also been devised. For example, in the water treatment device disclosed in Patent Document 1, when returning the well water pumped up in the mountain retaining work from the pouring well provided in another place into the soil, the pumped well water is filtered and deaerated by the above-ground equipment. The fine particles and dissolved oxygen contained in the well water are removed.

Japanese Patent Laid-Open No. 10-34134

  However, in the water treatment apparatus of Patent Document 1, the well water before pumping in the pumping well and the well water after pouring in the pumping well are not treated, so the structures in the well and the aquifer caused by dissolved oxygen Internal clogging can still occur.

  Then, this invention aims at providing the dissolved oxygen removal system and the dissolved oxygen removal method which can prevent further the clogging of the structure in a well or the inside of an aquifer resulting from the dissolved oxygen of well water. To do.

  The present invention includes a well in which well water is poured and pumped or pumped, a deaeration pipe having one end inserted into the well, and the other end of the deaeration pipe, and the well water is introduced from one end into the deaeration pipe to a predetermined height. A dissolved oxygen removal system for well water comprising a vacuum pump for pulling up.

  When the vacuum pump is operated in this dissolved oxygen removal system, the well water is pulled into the deaeration pipe from one end of the deaeration pipe, and the water surface in the deaeration pipe stops at a height corresponding to the water head pressure corresponding to the degree of decompression. As the pressure is reduced, dissolved oxygen from the well water is degassed from the well water and exits from the water surface in the deaeration pipe. Since this dissolved oxygen removal system directly targets the well water in the well, the dissolved oxygen in the well water can be reduced compared to the conventional dissolved oxygen removal system, and the well oxygen in the well caused by the dissolved oxygen in the well water can be reduced. Clogging inside the structure or aquifer can be further prevented.

  Here, the deaeration pipe may have a widened portion having an inner diameter widened in a height range sandwiching a water surface height in the deaeration pipe of the well water that is pulled into the deaeration pipe when the vacuum pump is operated. preferable. As pressure reduction by the vacuum pump proceeds, dissolved oxygen is degassed, and part of the well water is vaporized to expand the volume. The deaeration pipe is provided with a widening part to increase the internal volume, and the water surface in the deaeration pipe is positioned in the widening part, thereby facilitating gas-liquid separation, and the water level accompanying changes in the internal pressure of the deaeration pipe due to vaporization of well water It is also possible to mitigate changes.

  It is preferable that one end of the deaeration pipe is located below the surface of the well water in the well. If one end does not reach the surface of the well water, in order for the well water to be pulled up from the deaeration pipe after the vacuum pump is operated, groundwater enters the well from the aquifer while sucking the air in the well. Then we have to wait for the water level in the well to rise until one end is located below the surface. At this time, the water level in the well fluctuates greatly. If one end is located below the surface of the well water in advance, such fluctuations in the water level in the well can be kept small.

  As one aspect of the dissolved oxygen removal system of the present invention, the deaeration pipe has a branch pipe branched from a position between one end and the other end, and the end is inserted into the well. Circulates in the deaeration pipe or in the branch pipe at a position lower than the water surface height in the deaeration pipe or in the branch pipe of the well water pulled up into the deaeration pipe or the branch pipe when the vacuum pump is operated. You may comprise so that it may have a transfer pump which transfers well water. According to this dissolved oxygen removal system, the well water circulates in one direction while the flow direction of the well water is reversed between the deaeration pipe and the branch pipe by the operation of the transfer pump. As a result, the well water is agitated so that the portion of the well water in which the dissolved oxygen is sufficiently reduced and the portion in which the dissolved oxygen has not been sufficiently reduced are exchanged, so that the dissolved oxygen is efficiently degassed from the entire well water. be able to.

  Moreover, the dissolved oxygen removal system of the present invention has, as one aspect thereof, a degassing tube having a height range that sandwiches the water surface height in the degassing tube of well water that is pulled into the degassing tube when the vacuum pump is operated. In addition, it may be configured to further include a flow pipe having a widened portion with an enlarged inner diameter, one end inserted into the well, and the other end protruding into the widened portion at a position lower than the water surface height. Since the temperature of the well water in the widened portion decreases due to the reduced pressure, the density increases. The well water having increased density has a driving force that descends in the deaeration pipe, and as the descent, the well water in the well rises in the flow pipe and is guided into the widened portion. That is, a flow in which the well water circulates in one direction occurs between the deaeration pipe and the circulation pipe. Therefore, according to this dissolved oxygen removal system, dissolved oxygen can be efficiently degassed from the entire well water without using a special drive source for circulating the well water.

  Moreover, as for the dissolved oxygen removal system of this invention, the well is a water injection well in which water injection is performed with a water injection pipe, and the water injection pipe may be connected to the deaeration pipe. In this dissolved oxygen removal system, since a part of the deaeration pipe also serves as the water injection pipe, the structure of the water injection well is simplified.

  Moreover, as for the dissolved oxygen removal system of this invention, the well may be a pumping well in which pumping is performed by a pumping pipe as one aspect | mode. According to this, clogging of the in-well structure and the pumping pump due to the dissolved oxygen in the well water can be further prevented.

  In addition, the present invention has a well water, in which one end of the deaeration pipe is inserted into the well with respect to the well where water injection or pumping is performed, and the well water is supplied from the one end of the deaeration pipe into the deaeration pipe using a vacuum pump. Provided is a method for removing dissolved oxygen from well water that is raised to a height equivalent to the water head pressure. According to this method, dissolved oxygen in the well water is vaporized and degassed from the well water as the vacuum pump is decompressed. In this method, since the well water in the well is directly degassed, the dissolved oxygen in the well water can be reduced as compared with the conventional dissolved oxygen removal system, and the structure in the well caused by the dissolved oxygen in the well water or Clogging inside the aquifer can be further prevented.

  ADVANTAGE OF THE INVENTION According to this invention, the dissolved oxygen removal system and dissolved oxygen removal method which can prevent further the clogging of the structure in a well or the inside of an aquifer resulting from dissolved oxygen of well water can be provided. .

It is a figure which shows the dissolved oxygen removal system which concerns on 1st Embodiment. It is a figure which shows the use condition of the dissolved oxygen removal system which concerns on 1st Embodiment. It is a figure which shows the use condition of the dissolved oxygen removal system which concerns on 2nd Embodiment. It is a figure which shows the use condition of the dissolved oxygen removal system which concerns on 3rd Embodiment. It is a figure which shows the dissolved oxygen removal system which concerns on 4th Embodiment. It is a figure which shows the use condition of the dissolved oxygen removal system which concerns on 4th Embodiment. It is a figure which shows the use condition of the dissolved oxygen removal system which concerns on 5th Embodiment.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the drawings. In addition, in each figure, the same code | symbol is attached | subjected to the same part or an equivalent part, and the overlapping description is abbreviate | omitted.

  In this specification, “well water” refers to water that has permeated into the well of the ground water, water that has been injected and remains in the well, and further from the well by the operation of the vacuum pump. Water that has been pulled up into the deaeration tube.

<First Embodiment>
As a first embodiment of the present invention, a system for removing dissolved oxygen from well water in a water injection well will be described with reference to FIGS. 1 and 2. As shown in FIG. 1, the dissolved oxygen removal system 1 </ b> A of the present embodiment is connected to a water injection well 2 to which a water injection pipe used for water injection is attached, a deaeration pipe 3 inserted into the water injection well 2, and a deaeration pipe 3. The vacuum pump 4 is provided. The water injection pipe is not shown.

  The water injection well 2 is formed by digging the ground to the depth of an aquifer that holds groundwater, and has well water W therein. The inner wall surface of the water injection well 2 is covered with a well structure to prevent collapse. As the structure in the well, an iron plate 21 is used in a formation shallower than the aquifer (for example, a layer having no groundwater flow such as a clay layer), and a mesh-like strainer 22 is used in the aquifer. ing. At the time of water injection, the well water W enters the aquifer through the strainer 22.

  The upper part of the water injection well 2 is sealed with a lid 23 through which the deaeration pipe 3 passes. An open valve V <b> 1 for adjusting the atmospheric pressure in the water injection well 2 is attached to the lid 23.

  The deaeration pipe 3 is attached so as to extend over the inside and outside of the water injection well 2 so that the length direction thereof faces the vertical direction. One end (lower end) 31 of the deaeration pipe 3 is inserted into the water injection well 2 so as to extend downward through the lid 23, and is located below the surface of the well water W. The other end (upper end) 32 of the deaeration pipe 3 is connected to the vacuum pump 4 at the ground portion.

  The cross-sectional shape of the deaeration tube 3 is preferably circular, and the inner diameter is preferably 1 cm to 5 cm.

  The deaeration pipe 3 has an inner diameter widened in a height range (see also FIG. 2) that sandwiches the water surface height in the deaeration pipe 3 of the well water W pulled up into the deaeration pipe 3 when the vacuum pump 4 is operated. The widened portion 33 is provided. In this embodiment, the widening part 33 exists in the ground part.

  The cross-sectional shape of the widened portion 33 is preferably circular, and the inner diameter is preferably 5 cm to 30 cm. Or it is preferable that the internal diameter of the wide part 33 is 3 to 10 times the internal diameter of parts other than the wide part 33. FIG.

  The deaeration pipe 3 has an open valve V <b> 2 for adjusting the atmospheric pressure in the deaeration pipe 3 at a position above the widened portion 33.

  A vacuum pump 4 is connected to the other end 32 of the deaeration pipe 3, and the deaeration pipe 3 and the vacuum pump 4 are communicated with each other. The deaeration pipe 3 is provided with a valve V3 for blocking communication with the vacuum pump 4 at a position close to the other end 32.

  Next, a method for removing dissolved oxygen from the well water W using the dissolved oxygen removing system 1A will be described. When the vacuum pump 4 is operated with the open valves V1, V2 and V3 closed and the valve V3 is opened, the well water W is pulled up from the one end 31 of the degas pipe 3 into the degas pipe 3 as shown in FIG. The water surface in the deaeration pipe 3 stops when the pressure is raised to a height corresponding to the water head pressure corresponding to the degree of pressure reduction. The stopped water surface is located in the widened portion 33.

  When the well water W is pulled up into the deaeration pipe 3, the water level in the water injection well 2 is lowered by the volume raised, but the one end 31 of the deaeration pipe 3 is still located below the surface of the well water W.

  Here, the height (h) of the water surface in the deaeration pipe 3 with respect to the water surface in the water injection well 2 is about 10 m at the maximum (water head pressure when the absolute pressure becomes approximately 0 kPa by the vacuum pump 4) )

  Then, the dissolved oxygen in the well water W is degassed from the well water W as the pressure is reduced, and exits from the water surface in the deaeration pipe 3. The degassed well water W is sequentially degassed by the concentration diffusion of oxygen remaining in the well water W based on the decrease in dissolved oxygen. In the deaeration pipe 3, convection occurs based on a change in the density difference of the well water W, and the well water W accumulated in the lower part of the well is guided into the deaeration pipe 3 to promote deaeration.

  The deaeration time varies depending on the amount of well water W and the amount of dissolved oxygen, but is preferably about 1 to 10 minutes. When ending deaeration, valve | bulb V3 is closed, the vacuum pump 4 is stopped, opening and closing of open valve V1, V2 is adjusted, and the atmospheric | air pressure in the deaeration pipe | tube 3 and the water injection well 2 is returned. Along with this, the well water W that has been lifted into the deaeration pipe 3 descends, and the position of the water surface returns to the state shown in FIG.

  Since the dissolved oxygen removal system 1A directly targets the well water W in the water injection well 2, the dissolved oxygen in the well water W can be reduced as compared with the conventional dissolved oxygen removal system. It is possible to further prevent clogging of the structure in the well (here, the strainer 22) or the inside of the aquifer caused by. Moreover, it can prevent that the strainer 22 rusts by the influence of dissolved oxygen.

  Further, in the dissolved oxygen removal system 1A, when the pressure reduction by the vacuum pump 4 proceeds, the dissolved oxygen is degassed, and a part of the well water is vaporized to expand the volume. Here, since the deaeration pipe 3 has a widened part 33 whose inner diameter is increased by increasing the inner diameter, and the water surface in the deaerated pipe 3 is located in the widened part 33, gas-liquid separation is easy. Thus, the change in the water level accompanying the change in the internal pressure of the deaeration pipe 3 due to the vaporization of the well water W is alleviated.

  Moreover, in this embodiment, since the one end 31 of the deaeration pipe 3 is located under the water surface of the well water W in the water injection well 2, compared with the case where the one end 31 is not under the water surface, the influence on the water level of the well water W is reduced. It can be kept small. That is, if the end 31 does not reach the surface of the well water W, the well water W can be pulled up from the deaeration pipe 3 after the vacuum pump 4 is operated. It must wait for the groundwater from the water layer to enter the water injection well 2 and the water level in the water injection well 2 to rise until one end 31 is located below the water surface. At this time, the water level in the water injection well 2 varies greatly. If the one end 31 is previously positioned below the surface of the well water W, the fluctuation of the water level in the water injection well 2 can be suppressed small.

  In addition, the water injection with respect to the water injection well 2 can be performed also during deaeration.

<Second Embodiment>
A second embodiment of the present invention will be described. As shown in FIG. 3, the dissolved oxygen removal system 1B of the second embodiment is different from the dissolved oxygen removal system 1A of the first embodiment in that the deaeration pipe 3 has a branch pipe 3a and a branch. A transfer pump 34 is attached to the pipe 3 a, and the well water W is actively circulated together with the deaeration pipe 3.

  The deaeration pipe 3 of this embodiment has a branch pipe 3 a that branches at the lowermost part 33 a of the widened portion 33. The branch pipe 3 a extends downward so as to run in parallel with the deaeration pipe 3, penetrates the lid 23 and enters the water injection well 2, and the end 31 a reaches below the surface of the well water W. In other words, the upper part of the degassing pipe 3 below the widened part 33 and the branch pipe 3a both open at the lowermost part 33a of the widened part 33 and the lower ends 31 and 31a are below the surface of the well water W. positioned. The distance between the lowermost portion 33a of the widened portion 33 and the lower ends 31 and 31a of the deaeration pipe 3 is set to a length not exceeding 10 m.

  A transfer pump 34 for transferring the well water W flowing through the branch pipe 3a is attached to the ground portion in the middle of the branch pipe 3a. This mounting height corresponds to a position lower than the water surface height in the branch pipe 3a of the well water W pulled up into the branch pipe 3a when the vacuum pump 4 is operated.

  The type of the transfer pump 34 is not limited as long as it can transfer water. Here, the transfer pump 34 is attached so as to transfer the well water W upward.

  In this dissolved oxygen removal system 1B, if the transfer pump 34 is operated when the dissolved oxygen is degassed by the operation of the vacuum pump 4, the well water W flowing through the branch pipe 3a is transferred upward, and the widening portion 33 You will be guided in. In this manner, the well water W in the widened portion 33 descends in the deaeration pipe 3 and returns into the water injection well 2. That is, the well water W circulates in one direction while the flow direction of the well water W is reversed between the deaeration pipe 3 and the branch pipe 3a (see the arrow in FIG. 3). As a result, the well water W is agitated so that the portion of the well water W where the dissolved oxygen is sufficiently reduced and the portion where the dissolved oxygen is not sufficiently reduced are exchanged. Can be degassed.

  In this embodiment, since the flow direction of the well water W in the deaeration pipe 3 is determined in one direction, oxygen concentration diffusion and natural convection are formed in the first embodiment, particularly when the inner diameter of the deaeration pipe 3 is small. Useful when difficult.

  In the above description, the mode in which the well water W flowing through the branch pipe 3a is transferred upward by the transfer pump 34, but the well water W may be transferred downward. In the above description, the transfer pump 34 is attached to the branch pipe 3a. However, the transfer pump 34 may be attached to the deaeration pipe 3 at the same height position.

  Moreover, in the said description, although the aspect which has one branch pipe 3a was shown, multiple branch pipes 3a may be sufficient. Moreover, in the said embodiment, although the branch pipe 3a was shown in the position below the wide part 33 and the position below the water surface in the deaeration pipe 3 at the time of deaeration, the branch pipe 3a is, for example, It may be branched at a position above the widened portion 33.

<Third Embodiment>
A third embodiment of the present invention will be described. As shown in FIG. 4, the dissolved oxygen removal system 1C of the third embodiment is different from the dissolved oxygen removal system 1A of the first embodiment in that it has a flow pipe 5 in addition to the deaeration pipe 3, and A part of the structure of the ground part is covered with the heat insulating material 6.

  The flow pipe 5 provided in the dissolved oxygen removal system 1C of the present embodiment is arranged so that the length direction is in the vertical direction, and the lower end 51 thereof is inserted into the water injection well 2 through the lid 23, and the water surface. Below, it is located at the same height as the one end 31 of the deaeration tube 3. The upper end 52 of the flow pipe 5 penetrates the lowermost portion 33a of the widened portion 33 and protrudes into the widened portion 33, and the widened portion 33 of the well water W that is pulled up into the widened portion 33 when the vacuum pump 4 is operated. It has reached a position lower than the water level inside.

  Of the structure of the ground portion provided in the dissolved oxygen removal system 1 </ b> C, the widened portion 33 of the deaeration tube 3, the portion below the widened portion 33, and the flow pipe 5 are covered with the heat insulating material 6. As a material of the heat insulating material 6, for example, glass wool or concrete can be used.

  In the dissolved oxygen removal system 1C, the density of the well water W in the widened portion 33 is decreased by the reduced pressure due to the operation of the vacuum pump 4, and thus the density is increased. The well water W having an increased density has a driving force that descends in the deaeration pipe 3, and the well water W in the water injection well 2 rises in the flow pipe 5 and is guided into the widened portion 33 along with the descent. (See arrow in FIG. 4). That is, a flow in which the well water W circulates in one direction occurs between the deaeration pipe 3 and the circulation pipe 5. Therefore, according to this dissolved oxygen removal system 1C, dissolved oxygen can be efficiently degassed from the entire well water W without using a special drive source for circulating the well water W.

  In addition, since a part of the deaeration pipe 3 and the flow pipe 5 is covered with the heat insulating material 6, since the well water W in the widened portion 33 cooled by the reduced pressure is kept warm, the density of the well water W descending with increased density is decreased. Driving force is easily maintained.

  In the present embodiment, the temperature monitoring sensor for monitoring the temperature of the well water W and the well water in the monitoring portion are cooled so that the well water W in the portion covered with the heat insulating material 6 is not cooled and condensed. A heating means may be provided for heating the well water W by supplying heat when it is too much.

  Moreover, in the said description, although 1 C of dissolved oxygen removal systems showed the aspect provided with the one distribution pipe 5, you may provide the multiple distribution pipes 5. FIG.

<Fourth Embodiment>
A fourth embodiment of the present invention will be described. As shown in FIGS. 5 and 6, the dissolved oxygen removal system 1 </ b> D of the fourth embodiment is different from the dissolved oxygen removal system 1 </ b> A of the first embodiment in that a water injection pipe 7 is connected to the deaeration pipe 3. It is a point.

  The deaeration pipe 3 of the present embodiment is connected to the water injection pipe 7 at a position above the position having the widened portion 33. The other end of the water injection pipe 7 is connected to a water injection pump (not shown), and a valve V4 is provided between the connection portion with the deaeration pipe 3 and the water injection pump. It can be switched to stop. In addition, a drain valve V5 is provided between the connecting portion of the water injection pipe 7 to the deaeration pipe 3 and the valve V4. By opening the drain valve V5, water accumulated in the water injection pipe 7 can be drained, and at the same time, the air pressure in the water injection pipe 7 and the deaeration pipe 3 can be adjusted.

  FIG. 5 shows a state in which water is injected into the water injection well 2. When the water injection pump is operated with the open valves V1, V2, V3 and the drain valve V5 closed and the valve V4 opened, water is supplied from the water injection pipe 7 and enters the deaeration pipe 3 while filling it (see FIG. 5), reach the water injection well 2.

  FIG. 6 shows a state where the well water W is degassed. In order to shift from the water injection state shown in FIG. 5 to the deaeration state shown in FIG. 6, the valve V4 is closed to stop the water injection pump, and the drain valve V5 is opened to accumulate in the water injection pipe 7. Drain the water and close the drain valve V5. Thereafter, the same deaeration procedure as in the first embodiment is performed.

  In this dissolved oxygen removal system 1D, since a part of the deaeration pipe 3 also serves as the water injection pipe 7, the structure of the water injection well 2 is simplified.

  In addition, in the said description, although the aspect in which the water injection pipe 7 was connected in the position above the position which has the wide part 33 was shown, the position (namely, the water injection pipe 7 is lower than the position which has the wide part 33 (that is, It may be connected on the lower side of the water surface in the deaeration pipe 3 during deaeration.

<Fifth Embodiment>
As a fourth embodiment of the present invention, a system for removing dissolved oxygen from well water in a pumping well will be described with reference to FIG. As shown in FIG. 7, the dissolved oxygen removal system 1E of the fifth embodiment is different from the dissolved oxygen removal system 1A of the first embodiment in that the deaeration target is not the water injection well but the pumping well 8 The point which has the pumping pipe 9 used for pumping instead of the water injection pipe used for water pouring, and the point which has the characteristics in the shape of the deaeration pipe 3 are.

  A pumping pipe 9 is attached to the pumping well 8. A pumping pump 91 is attached to the ground portion of the pumping pipe 9, and an end extending to the inside of the pumping well 8 is located below the surface of the well water W. A strainer 92 that prevents suction of fine particles is wound around the end of the pumping pipe 9 so that the fine particles contained in the well water W to be pumped are not excessively taken into the pumping pump 91.

  The deaeration pipe 3 has an opening 35 on the side surface of the portion immersed in the well water W. The opening 35 is preferably constituted by a check valve that allows water to flow only in one direction from the inside to the outside of the deaeration pipe.

  The widened portion 33 of the deaeration pipe 3 is larger in height than the widened portion in the first embodiment, and the lower end side of the widened portion 33 penetrates the lid 23 and enters the pumping well 8. . The height of the widened portion 33 is preferably 3 to 10 times the diameter.

  According to the dissolved oxygen removal system 1E, clogging of the in-well structure (here, the strainer 92 of the pumping pipe 9) and the pumping pump 91 due to the dissolved oxygen of the well water W can be further prevented.

  In general, pumping wells intermittently repeat the pumping of groundwater that begins to ooze from the aquifer, but as the implementation period becomes longer, a staying portion occurs at the bottom of the well. Fine particles derived from groundwater are accumulated in the staying portion, and when well water W containing a large amount of the fine water is pumped, the strainer 92 and the pumping pump 91 of the pumping pipe 9 may be clogged. Therefore, it is desired to discharge the clogging substances such as fine particles at an early stage before they accumulate.

  Here, in the dissolved oxygen removal system 1E of the present embodiment, since the deaeration pipe 3 has the opening 35 on the side surface of the portion immersed in the well water W, the inside of the deaeration pipe 3 and the pumping well 8 after the completion of the deaeration. When the well water W in the deaeration pipe 3 descends into the pumping well 8, water flows toward the outside of the deaeration pipe 3 not only from the lower end 31 but also through the opening 35. Due to this water flow, the staying portion in the pumping well 8 is agitated, the fine particles diffuse, and the concentration of the fine particles is reduced. And it becomes easy to discharge | emit microparticles | fine-particles with the pumping pipe 9, and it is suppressed that the strainer 92 and the pumping pump 91 of the pumping pipe 9 clog. Further, in this embodiment, since the volume of the widened portion 33 is larger than the volume of the widened portion 33 of the first embodiment, the amount of water flow from the opening 35 is increased, and pumping by the water flow is performed. The stirring efficiency of the staying part in the well 8 is increased.

  The preferred embodiment of the present invention has been described above, but the present invention is not limited to the above embodiment. For example, the above embodiments can be implemented in combination as appropriate. For example, although 2nd Embodiment, 3rd Embodiment, and 4th Embodiment showed the application example with respect to a water injection well, these structures are also applicable to a pumping well.

  Moreover, in each said embodiment, although the one end 31 of the deaeration pipe 3 showed the aspect located under the water surface of the well water W, the said one end 31 may be located in a position higher than a water surface.

  Moreover, in each said embodiment, although the upper part of the well showed the aspect sealed with the lid | cover 23, the upper part of the well may be open | released.

  Further, the widened portion does not necessarily have to be on the ground portion.

  Moreover, although each said embodiment showed the aspect always equipped with the water injection pipe or the pumping pipe (however, illustration is abbreviate | omitted in 1st Embodiment-3rd Embodiment), it is poured at the time of deaeration. It is good also as an aspect which replaces and uses a water pipe or a pumping-up pipe with a deaeration pipe.

  1A, 1B, 1C, 1D, 1E ... dissolved oxygen removal system, 2 ... water injection well, 3 ... deaeration pipe, 3a ... branch pipe, 4 ... vacuum pump, 5 ... flow pipe, 6 ... heat insulating material, 7 ... water injection pipe, DESCRIPTION OF SYMBOLS 8 ... Pumping well, 9 ... Pumping pipe, 31 ... Lower end (one end) of deaeration pipe, 31a ... Lower end (end part) of branch pipe, 32 ... Upper end (other end) of deaeration pipe, 33 ... Widening part, 34 ... Transfer Pump, 51 ... lower end (one end) of the flow pipe, 52 ... upper end (the other end) of the flow pipe, W ... well water.

Claims (8)

A well that has well water and is filled or pumped,
A deaeration tube having one end inserted into the well;
A dissolved oxygen removal system for well water, comprising: a vacuum pump that communicates with the other end of the deaeration pipe and pulls the well water up to a predetermined height from the one end into the deaeration pipe.   The deaeration pipe has a widened portion with an inner diameter widened in a height range sandwiching a water surface height in the deaeration pipe of the well water that is pulled into the deaeration pipe when the vacuum pump is operated. Item 2. The dissolved oxygen removal system for well water according to Item 1.   The dissolved oxygen removal system for well water according to claim 1 or 2, wherein the one end is located below the surface of the well water in the well. The deaeration pipe branches from a position between the one end and the other end, and has a branch pipe having an end inserted into the well.
The deaeration pipe or the branch pipe is located at a position lower than the water surface height in the deaeration pipe or in the branch pipe of well water that is pulled up into the deaeration pipe or the branch pipe when the vacuum pump is operated. The dissolved oxygen removal system for well water according to any one of claims 1 to 3, further comprising a transfer pump configured to transfer the well water flowing through the trachea or the branch pipe. The degassing pipe has a widened portion with an inner diameter widened in a height range sandwiching a water surface height in the degassing pipe of well water pulled into the degassing pipe when the vacuum pump is operated,
The dissolved oxygen removal of well water according to any one of claims 1 to 3, further comprising a flow pipe having one end inserted into the well and the other end protruding into the widened portion at a position lower than the water surface height. system. The well is a water injection well in which water is injected by a water injection pipe,
The dissolved water removal system for well water according to any one of claims 1 to 3, wherein the water injection pipe is connected to the deaeration pipe.   The dissolved oxygen removal system for well water according to any one of claims 1 to 3, wherein the well is a pumping well in which pumping is performed by a pumping pipe. Hold well water, insert one end of the deaeration pipe into the well for wells to be poured or pumped,
A method for removing dissolved oxygen from well water, wherein the well water is pulled up from one end of the deaeration pipe into the deaeration pipe to a height corresponding to a predetermined head pressure using a vacuum pump.

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