JPH0938660A - Method for removing dissolved oxygen in water and device for removing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to efficiently remove the dissolved oxygen in water to be treated by dispersing fluid with a gas dispersing device disposed to communicate small chambers, thereby reducing the sizes of the bubbles of the inert gas forcibly fed into the water to be treated and increasing the gas-liquid boundary area. SOLUTION: The water to be treated from which the dissolved oxygen is to be removed is forcibly fed via a supplying pipe 4 for the water to be treated by a pump 3 of a removing device 1. The inert gas of a compressed cylinder 6 is forcibly fed via a flow rate regulating valve 8 into the supplying pipe 4 for the water to be treated. Further, the fluid mixture composed of the water to be treated and the inert gas is supplied to the gas dispersing device 2 and is subjected to gas replacement by the dissolution of the inert gas and the release of gaseous oxygen, by which the dissolved oxygen in the water is removed. On the other hand, the treated water is admitted from a discharge port 5a of a treated water discharge pipe 5 into the primary chamber 9a of a tank 9. The movement of the air bubbles of the treated water to a secondary chamber 9b side is prohibited by a partition 13 and the air bubbles are erased only by the primary chamber 9a. The treated water moving into the secondary chamber 9b is drained from a drain pipe 12 in the state of not mixing the air bubbles therewith.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention produces uniform and fine bubbles of inert gas by means of making the flow state of water complicated and making fine bubbles of inert gas without using mechanical stirring means. A method and apparatus for removing dissolved oxygen in water, which is dispersed in water to remove dissolved oxygen.

[0002]

2. Description of the Related Art Generally, about 8 to 10 ppm of oxygen is dissolved in water used as raw material water and washing water in the food industry at atmospheric pressure and room temperature, and food is deteriorated by the oxidizing action of the dissolved oxygen. In addition, the dissolved oxygen is sufficiently removed because of contamination with bacteria.

Various methods have been conventionally known as means for removing dissolved oxygen in water. As examples thereof, heating deaeration, vacuum deaeration, etc. are known. In this case, extra energy for heating the water to be treated from which dissolved oxygen should be removed or cooling the treated water that has been heated and degassed, a heating and cooling device are required. In particular, a vacuum device and a sealing means for maintaining a vacuum state and extra energy for that are required, and none of the removing means is satisfactory in terms of cost, handling and maintenance.

Compared with the above-mentioned removal means such as heating deaeration and vacuum deaeration, it is advantageous in terms of cost and energy saving without using extra energy and various devices such as heating, cooling and vacuum. As a removing means, a bubble column type device which does not use a mechanical stirring means is known.

The degassing tower a, which is a bubble tower type device, diffuses an inert gas against a water pressure from a gas disperser b provided at the bottom of the degassing tower a as shown in FIG. The water to be treated is caused to flow in from the top of the degassing tower a and drained from the bottom of the degassing tower a by a countercurrent contact operation.

However, the bubble diameter of the inert gas diffused by the above means is about 0.2 mm even if the pore diameter of the gas disperser b is small, and the gas is dispersed from the pores of the gas disperser b. Since the average bubble diameter to be vaporized is several mm or more (about 2 to 10 mm), the gas-liquid contact area is small, and the rising speed is as fast as 20 cm / sec or more and the removal efficiency of dissolved oxygen is low, and Moreover, there is a drawback that the treated water is drained without contacting with the inert gas while keeping the concentration of dissolved oxygen high in a short circuit.

[0007]

DISCLOSURE OF THE INVENTION According to the present invention, the bubble diameter of an inert gas is made fine by a gas dispersion device to increase the gas-liquid interfacial area to improve the removal efficiency of dissolved oxygen, and the treated water is completely made up of bubbles. It can be used as raw material water or washing water in a non-turbid state, eliminates short-circuit discharge of treated water, reduces the size of the gas dispersion device, and rattles the discs that make up the gas dispersion assembly element. To prevent problems such as short-circuited flow and dispersion failure due to pulsating flow, and to simplify the assembly of the gas dispersion device, and to securely attach the seal member to prevent short-term flow of fluid. Restricted to prevent lowering of mixing efficiency, maintain good gas dispersion efficiency, prevent leakage of fluid from lid at the same time, facilitate machining of casing, and visually check It is difficult to There is provided St. removal method and apparatus for removing water dissolved oxygen was set to prevent seal failure due to biting of the seal member.

[0008]

In view of the problems such as low efficiency of removing dissolved oxygen based on the above-mentioned conventional technique, the present invention has two open circular chambers formed in front of each other and communicated with each other. Right angle collision with fluid by gas dispersion element,
Dispersing, merging, meandering, vortexing, etc. are given to disperse, and the bubbles of the inert gas injected into the water to be treated are made into fine bubbles to increase the gas-liquid interface area and improve the removal efficiency of dissolved oxygen. The above-mentioned drawbacks are not solved by providing a method and a device for removing dissolved oxygen in water.

A treated water supply pipe, which is composed of a gas dispersion device and a tank and which supplies the treated water from which dissolved oxygen is to be removed under pressure at atmospheric pressure or higher, is connected to the inlet of the gas dispersion device. An inert gas injection pipe for injecting an inert gas is connected in the middle of the process, and a treated water discharge pipe is connected to the outlet of the gas dispersion device.

Further, the inside of the tank is divided into a primary chamber and a secondary chamber by a partition wall having only water permeability, the treated water discharge pipe is connected to the primary chamber, and the drain pipe is connected to the secondary chamber.

The gas dispersion device has a cylindrical casing having an inlet and an outlet at both ends, and a large number of small open-ended cylindrical chambers having a side wall perpendicular to the front and facing each other. It is composed of a plurality of gas dispersion elements formed by concentrically superposing two discs as a set.

The large-diameter disc is formed with an outer diameter which makes water contact with the inner peripheral surface of the casing, and a through hole is formed in the center, and the outer diameter of the small-diameter disc is the inner periphery of the casing. The small chamber of the large-diameter disk and the small chamber of the small-diameter disk have a size such that a flow path is formed between them and the inner peripheral surface of the small-diameter disk. The gas dispersion elements are arranged in different positions so that they communicate with the small chambers of the gas chambers.The gas dispersion elements are arranged in the casing so that discs of the same diameter are adjacent to each other, and the inlet and outlet of the casing communicate with the communication holes. Large disks are placed on both sides so that it will do.

Further, as another gas dispersion device, a lid body having an inlet and an outlet formed at both ends of a cylindrical casing is detachable, and a cylindrical body having an outer diameter inserted into the casing by an elastic body. To form a ring-shaped annular seal body by integrally molding the collar pieces inward from both ends of the tubular body, and the two large and small circles are formed in the internal space of the annular body in the annular seal body. A plate is arranged to form a gas dispersion collecting element, the gas dispersion collecting elements are arranged in a casing, and a dimension between both ends of the gas dispersion collecting element is set to be larger than a dimension between both ends of the casing.

Further, as another gas dispersion device, a columnar projection is provided which is inserted into a casing having a detachable lid, and a half-seal-shaped seal seating surface is provided on the peripheral edge side of the tip of the columnar projection. In addition, the outer diameter of the large-diameter disk is formed so that it does not come into close contact with the inner peripheral surface of the casing, and a half-seal-shaped seal seat surface is formed on the peripheral edge of the back surface where no small chamber is formed. However, two large and small discs are connected to form a gas dispersion element so that the small chambers are in different positions so that they communicate with other small chambers that face each other, and these gas dispersion elements have the same diameter. Discs are overlapped so that they are adjacent to each other and arranged in the casing, and a seal member is provided in a seal groove defined by the adjacent seal seat surfaces, and the seal seat surface that is the bottom of the seal groove is tapered. Is done.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 is a device for removing dissolved oxygen in water according to the present invention, and the removing device 1 is a mechanical device such as a stirring blade. The gas dispersion device 2 is used, which does not use a stirring means, but complicates the flow state of the water to be treated and makes inert gas such as nitrogen, helium, neon, and argon into fine bubbles.

As the constitution of the removing device 1, the treated water supply pipe 4 for supplying to the inlet side 2a of the gas dispersion device 2 the treated water from which the dissolved oxygen is to be removed from the pump 3 under atmospheric pressure or higher. And a treated water discharge pipe 5 for discharging treated water from which dissolved oxygen has been removed to the outlet side 2b of the gas dispersion device 2.
Are connected.

An inert gas injection pipe 7 for injecting the pressurized inert gas in the compression cylinder 6 into the treated water supply pipe 4 is connected in the middle of the treated water supply pipe 4. The gas injection pipe 7 is provided with a flow rate adjusting valve 8 for adjusting the gas flow rate.

Further, the treated water discharge pipe 5 is connected to a tank 9 for containing treated water, and the tank 9 is provided with a gas exhaust port 11 on an upper portion of a hollow tank body 10 and a tank body. 10 Drain pipe for draining treated water at the bottom
12 is connected to the upper side of the drain port 12a of the drain pipe 12 from a non-woven fabric having only water permeability that does not allow the passage of fine bubbles of inert gas, a sponge, and a filter body that is a permeable porous body that is an industrial ceramic. The partition 13 is provided, and this partition 13
The upper chamber in the tank 9 is divided into a primary chamber 9a and the lower chamber is divided into a secondary chamber 9b.

The treated water discharge pipe 5 penetrates the lower part of the tank main body 10 and the partition wall 13 and the discharge port 5a at the end is the primary chamber.
9a, or as shown by the alternate long and short dash line in the figure, the treated water discharge pipe 5 penetrates the upper part of the tank body 10, and the discharge port 5a at its end is located in the primary chamber 9a. You may connect as you would.

Further, as another embodiment of the tank 9, a partition wall 13 is provided in the tank body 10 in the vertical direction, and the partition wall 13 allows the right chamber in the tank 9 to be a primary chamber 9a and the left chamber to be a secondary chamber. Room
It is divided into 9b, the treated water discharge pipe 5 of the overflow type is provided in the primary chamber 9a, and the drain pipe 12 is provided in the secondary chamber 9b.
Is arranged.

A gas exhaust port 11 is provided in the upper portion of the tank body 10 to connect the primary chamber 9a and the secondary chamber 9b to the outside.

Next, as a first embodiment of the gas dispersion device 2, flanges 22 and 22a projecting in the outer peripheral direction are formed at the openings at both ends of a cylindrical casing 21, respectively, and the end faces of the flanges 22 and 22a are formed. On the inlet side with a diameter smaller than the inner diameter of the casing 21
Plate-like lids 25, 25a having an inlet 23 which is 2a and an outlet 24 which is the outlet side 2b formed in the center are detachably mounted.

Reference numeral 26 designates a plurality of gas dispersion elements arranged in the axial direction in the hollow interior of the casing 21, and the gas dispersion elements 26 are arranged on the front surfaces facing each other as shown in FIGS. On the other hand, the cylindrical small chambers 27, 27 having a polygonal shape in the front view with the sidewall 32 formed at a right angle
Two large and small disks 28 and 29 with a large number of a arranged are set as a set and are concentrically superposed.

Further, the large-diameter disk 28 is formed with an outer diameter that is watertight with the inner peripheral surface of the casing 21, and a flow hole 30 is formed in the center thereof, while the small-diameter disk 29 is The outer diameter is separated from the inner peripheral surface of the casing 21 and the flow passage 31 is formed between the outer peripheral surface and the inner peripheral surface.
The size is formed.

Further, as shown in FIG. 6, the small chamber 2 of the large-diameter disk 28 is provided.
7 and 27a, and the small chambers 27, 27a of the small-diameter disk 29 are arranged so that their respective small chambers 27, 27a ... communicate with the opposite small chambers 27, 27a.

The gas dispersion elements 26 are arranged in series in the hollow inside of the casing 21 by stacking the disks having the same diameter so that they are adjacent to each other.

Further, large-diameter discs 28 are arranged on both sides of the gas dispersion element 26 in the serial state, and the circulation holes of the large-diameter discs 28 are arranged.
30 communicates with the inlet 23 and the outlet 24.

In the above-mentioned embodiment, the small chambers 27, 27a, ... Are shown as hexagonal in plan view, and a large number of cells are arranged in a honeycomb shape.
As shown in, the shape of the small chambers 27, 27a ...
It may be octagonal or the like, or may be circular (not shown).

Further, as another embodiment of the large and small discs 28, 29, as shown in FIGS. 11 and 12, arbitrary small chambers 27, 27a ...
By providing a protrusion 33 lower than the height of the upper end surface of the side wall 32 forming the small chambers 27, 27a ...
Turbulence can be positively generated in the fluid flow, the gas dispersion efficiency can be further improved, and the protrusion 33 is gradually reduced toward the central portions of the disks 28, 29, whereby the circumferential direction is reduced. The inner volumes of the outside and the inside in the diametrical direction of the small chambers 27, 27a arranged in a uniform manner can be made uniform to prevent pulsation and ensure a smooth flow.

Next, as to the second embodiment of the gas dispersion device 2, as shown in FIGS. 13 to 15, an elastic body (nitrile rubber, silicone rubber, fluororubber) which is a material used for packing, gaskets and the like is used. , Acrylic rubber, Teflon, etc.) to form a tubular body 35 with an outer diameter that is inserted in a loose fit with a slight gap between it and the inner peripheral surface of the casing 21. The collar pieces 36, 36a are integrally formed on the inner side to form a ring-shaped annular sealing body 37.

The axial length of the tubular body 35 of the annular seal 37 is approximately the same as the axial length of four large and small disks 28 and 29 concentrically stacked. I am letting you.

Further, a large-diameter disk 28 is formed with an outer diameter in close contact with the inner peripheral surface of the cylindrical body 35 in the annular seal body 37, and the outer diameter of the small-diameter disk is the inner circumference of the cylindrical body 35. It is sized so as to form a flow passage 31 between the inner peripheral surface and the surface away from the surface.

Large discs 28 are arranged on both sides, and the small chambers 27, 27a ...
A pair of gas distribution elements 26 consisting of two large and small discs 28 and 29, which are arranged in different positions so as to communicate with a ... Arranged inside is a gas dispersion collecting element 38.

Next, a plurality of gas dispersion collecting elements 38 are arranged in series inside the hollow of the casing 11, and the flange 2
A plurality of gas dispersion collecting elements 38 are sandwiched and fixed by the lids 25 and 25a by arranging the lids 25 and 25a on the end faces of the 2 and 22a and fixing them with bolts or the like, and arranged in the casing 21.

Here, the dimension L1 between both ends of the casing 21
On the other hand, a plurality of arranged gas dispersion collecting elements 38 are concentrically formed in a free state, and the collar pieces 36 and 36a of the ring-shaped seal body 37 are provided.
By setting a large dimension L2 between both ends in the continuous state in which the two are in contact with each other, a pressing force is applied to the collar pieces 36, 36a of the annular sealing body 37 in each gas dispersion collecting element 38, and this pressing force causes The collar pieces 36, 36a are compressed and deformed, and the elastic restoring force at that time presses the upper end surfaces of the side walls 32 of the small chambers 27, 27a ... into close contact with each other to improve the close contact state. , 36a are pressed against the back surface of the large-diameter disk 29 to maintain a good close contact state, thus perfecting the sealing function.

When the pressing force of the lids 25 and 25a is insufficient, the pressing force can be adjusted by interposing a flat plate ring spacer (not shown) made of an elastic body. Is a case where there are a plurality of gas dispersion collecting elements 38. When the gas dispersion collecting element 38 is used as a single body, the dimension L2 between both ends of the gas dispersion collecting element 38 is smaller than the dimension L1 between both ends of the casing 11. It should be large.

Next, in the third embodiment of the gas dispersion device 2, as shown in FIGS. 16 to 25, the outer diameter of the large diameter disk 28 in the first embodiment is set to the inner peripheral surface of the casing 11. It does not come in close contact with (small enough to fit loosely), and the small chamber 2
By forming a flat truncated cone-shaped pedestal portion 39 having a base diameter slightly smaller than the outer diameter of the disc 28 on a flat back surface on which 7, 27a ... Are not formed, the pedestal portion 39 The outer peripheral side of the disk 28 is formed into a depressed shape to form a seal seat surface.
Form 40.

The seal bearing surface 40 has a seal groove 54 which will be described later.
In order to define the above, a half is formed, and a part thereof is formed by an area formed in a tapered surface shape, and as a tapered surface portion, the seal member 55 in the seal groove 54 is pressed and contacted. It is a seat.

As another embodiment of the seal seat surface 40,
The pedestal portion 39 may be formed in a flat columnar shape, and may be formed in a half-groove shape in a recessed region formed by the outer peripheral surface of the pedestal portion 39 and the peripheral edge side of the back surface of the disc 28.

Further, a hub 42 is integrally formed at the center of the through hole 30 penetrating the center of the large-diameter disk 28, at the tip of the arm 41 pointing from the inner surface of the through hole 30 to the center, and at the center of the hub 42. Shaft hole 43
In addition to the above, a counterbore portion 44 formed in a concave shape with a predetermined depth is formed in the pedestal portion 39 around the circulation hole 30.

Next, a cylindrical boss 45 is provided at the center of the front surface of the small-diameter disk 29 where the small chambers 27, 27a ... Are formed, and a female screw hole 46 is screwed into the center of the boss 45. At the same time, on the outside of the same front surface, fitting pins 47, 47a that fit with the arbitrary outermost small chambers 27, 27a in the large-diameter disk 28 are provided in a protruding manner.

As shown in FIGS. 23 and 24, the small chambers 27, 27a provided at the front face are superposed at different positions so as to communicate with the other small chambers 27, 27a. Is passed through the shaft hole 43 and screwed into the female screw hole 46 to connect the two large and small disks 28 and 29 to each other to form the gas dispersion element 26.

Further, bolt insertion holes 49, 49a ... Are formed in the flanges 22, 22a of the casing 21, and a lid 25 for forming an inlet 23 and an outlet 24 attached to both ends of the casing 21, respectively.
25a is provided with a columnar protrusion 50 which is inserted into the openings at both ends of the casing 21 in a loosely fitted manner, and a seal seat similar to the two large and small disks 28 and 29 is provided on the peripheral edge side of the tip of the columnar protrusion 50. A surface 40 is formed, and an appropriate number of through screw holes 52 into which adjustment bolts 51 are screwed are formed at the portions facing the flanges 22 and 22a.

Then, the gas dispersion element 26, in which two large and small disks 28 and 29 are connected by a set screw 48 in series from the opening of the casing 21 to the inside of the hollow, is installed in the large disks 28 and in the small diameter. The disks 29 are arranged so that they are adjacent to each other, and the casing
When the lids 25 and 25a are mounted by the appropriate number of connecting bolts 53 and 53a with the columnar protrusions 50 inserted into the openings at both ends of the 21, they are formed on the large diameter disc 28 of the adjacent gas dispersion element 26. The seal seating surface 40 thus defined defines a substantially V-shaped and U-shaped seal groove 54.

A ring-shaped seal member 55, which has a predetermined squeezing margin by the seal groove 54 and the inner peripheral surface of the casing 21, is mounted in the seal groove 54 to form the gas dispersion device 2.

Here, as a method for mounting the seal member 54, first, the lid 25 is mounted in one opening of the casing 21 by an appropriate number of connecting bolts 53, 53a, and then the seal member 55, the gas dispersion element. 26 are arranged in series in the order of 26, and finally the lid 25a is attached to one opening of the casing 21 by an appropriate number of connecting bolts 53, 53a. A seal member 54 is mounted in the groove 54.

As the seal member 55, an O-ring, X
There are a ring, a D ring and the like, and the materials thereof include nitrile rubber, silicone rubber, fluororubber, acrylic rubber and Teflon.

Next, the method of removing dissolved oxygen in water according to the present invention will be described. The pump 3 in the removing apparatus 1 will be described.
The treated water from which the dissolved oxygen is to be removed is fed under pressure at a predetermined flow rate and above the atmospheric pressure through the treated water supply pipe 4, and the treated water supply pipe 4 The inert gas in the compression cylinder 6 is press-fitted at a predetermined flow rate through the flow rate adjusting valve 8.

The mixed fluid is used as the gas dispersion device 2
The flow becomes complicated in the inside as described later, and the inert gas flows through the gas dispersion device 2 in the state of being formed into fine bubbles. At the interface with the bubbles of the active gas, an equilibrium action depending on the solubility in water occurs, and gas exchange is performed by dissolution of the inert gas and release of oxygen gas to remove dissolved oxygen in water.

Next, when the treated water from which the dissolved oxygen has been removed in the gas dispersion device 2 flows into the primary chamber 9a of the tank 9 from the discharge port 5a of the treated water discharge pipe 5, the treated primary chamber 9a. Since the bubbles of the treated water entering the inside are stopped from moving to the secondary chamber 9b side by the partition wall 13, the bubbles rise only in the primary chamber 9a to be defoamed on the water surface and pass through the partition wall 13. Secondary chamber 9b
The treated water that has entered the inside is discharged through the drain pipe 12 in a state where the bubbles are not clouded at all.

Further, even in the ascending process of bubbles in the primary chamber 9a of the tank 9, if there is dissolved oxygen that cannot be completely removed in the gas dispersion device 2, gas replacement is naturally performed and further submersion in water is performed. Dissolved oxygen is removed.

When the primary chamber 9a is formed in the upper part of the tank 9 and the secondary chamber 9b is formed in the lower part of the tank 9, dissolved oxygen is removed and the treated water from which bubbles are removed does not come into contact with the atmosphere. Therefore, it has an advantage that oxygen in the atmosphere is not dissolved.

Next, regarding the mechanism of forming fine bubbles of the inert gas in the gas dispersion device 2, the mixed fluid of the water to be treated and the inert gas is introduced from the inlet 23 of the gas dispersion device 2 into the casing 21. When the mixed fluid flows under pressure into the space, the flow of the mixed fluid reaches the inside from the flow hole 30 of the gas dispersion element 26 on the upstream side as shown by the arrow in FIG. After being obstructed, the directions are changed, and through the small chambers 27, 27a ... Which communicate with each other, the states such as collision at right angles, dispersion, merging, meandering, and vortex flow in a radial direction from the central portion to a complex flow.

In this way, the upstream gas dispersion element 26
The mixed fluid that has reached the inner peripheral surface of the casing 21 after passing through is a gas dispersion element on the downstream side from the flow passage 31 formed by the inner peripheral surface of the casing 21 and the small-diameter disk 29.
26 enter each of the small chambers 27, 27a ..., and are gathered in the central part by a complicated flow such as right-angle collision, dispersion, merging, meandering, vortex flow as described above, and again from the flow hole 30 to the gas distribution element 26 on the downstream side. After entering, and then again through the small chambers 27, 27a ..., the gas is dispersed in the gas dispersion element 26 in a complicated and sequential manner by a right-angle collision, dispersion, merging, meandering, vortex flow, etc. from the center to the outside, and the flow state is maintained. As a result, the inert gas is made into fine bubbles, becomes turbid with the bubbles, and is discharged from the outlet 24.

As described above, the mixed fluid is contained in the small chambers 27, 27.
Right-angle collision with the bottom and side walls 32 of a ..., small chambers 27, 27a
Dispersion from… to other chambers 27, 27a…, chambers
27, 27a… to another small chamber 27, 27a… merging, meandering, and multiple small chambers 27, 27a… to each small chamber 27, 27a….
Fluid dynamic shear due to vortex flow into each chamber 2
Hydrodynamic shear when passing through the orifice, which is a communication path from 7, 27a ... to other small chambers 27, 27a, crushing by impact destruction, shearing when passing through the upper end surface of the side wall 32, mechanical The water to be treated and the inert gas are dispersed and mixed by cavitation or the like.

The total number of dispersions of the gas dispersion element 26 is determined by the number of small chambers 27, 27a ... Of the two large and small circular disks 28, 29 arranged radially in order from the center. In the case of the hexagonal shape in plan view shown in FIG. 9, there are three rows of discs 28 having a number of chambers of 6, 12, and 18 (total of 36 chambers), and the number of chambers is 3, 9, 15 3 rooms (total 27 rooms)
The total number of dispersions in the case of one fluid, which is the total of the gas dispersion elements 26 in which the circular discs 29 are superposed, reaches several thousand times, and if it is two fluids (water to be treated and inert gas) or more, naturally it is a multiplier. Product.

It should be noted that the above-mentioned total number of dispersion means the number of the mixed fluids to be generated while passing through the gas dispersion element 26 by the small chambers 27, 27a communicating with each other in the disk 28 and the disk 29. Yes, multiple gas distribution elements 26
In the case of consisting of, the product of the total number of dispersions of the gas dispersion element 26 is obtained, and can be appropriately increased or decreased by increasing or decreasing the number of rows of the small chambers 27, 27a.

Incidentally, in the gas dispersion device 2 using the gas dispersion assembly element 38 as well, right angle collision, dispersion, merging, meandering,
The vortex flow etc. are repeated and discharged.

In the second gas dispersion device 2 in which the gas dispersion collecting elements 38 are arranged, the dispersion mixing operation is performed in the same manner as described above, and the dimension L2 between both ends of the gas dispersion collecting element 38 is set to the casing 21. Set it to be larger than the dimension L1 of both ends of the
Since the gas dispersion collecting element 38 is attached to both ends of the disc and sandwiched and fixed, the small chambers 27, 27a in the disks 28, 29 are fixed.
It is possible to firmly maintain the close contact state of the upper end surface of the side wall 32 forming the.

Further, regarding the third gas dispersion device 2 in which the seal groove 54 is defined by the adjacent seal seating surfaces 40, the seal member 55 and the gas dispersion element 26 are sequentially arranged in the casing.
The seal member 55 can be mounted in the seal groove 54 only by inserting it into the seal groove 21, and the seal member 55 prevents short circuit of fluid between the outer diameter of the large-diameter disk 28 and the inner peripheral surface of the casing 21. When sealing can be performed so as to regulate the flow, and when the seal seat surface 40 is formed into a tapered surface, the tapered surface serves as a guide surface when the seal member 55 is mounted, as shown in FIG. Bite can be prevented.

Also, with respect to the fluid that is about to leak from between the end faces of the columnar protrusions 50 of the lids 25 and 25a and the rear face of the large diameter disc 28 of the gas dispersion collecting element 26, the seal seating surface of the columnar protrusions 50 is also prevented.
40 and the seal groove defined by the seal seat surface 40 of the disc 28
Since the seal member 55 is mounted inside the cylinder 54, leakage from the outer circumference of the columnar protrusion 50 can be prevented, and gaskets generally provided on the outer peripheral side of the columnar protrusion 50 are unnecessary.

Next, regarding the experimental result of the removal of dissolved oxygen in water, the gas dispersion device 2 has a hexagonal plan view of the small chambers 27, 27a ... And the number of the small chambers 27, 27a. A large-diameter disk 28 and a small-diameter disk 29 having 30 small chambers 27, 27a ... A mixed fluid of 4 kinds, 6 units, and 10 kinds of interior units, in which the water to be treated, which is tap water, and a high-purity (about 99, 9%) nitrogen gas as an inert gas are used in the gas dispersion device 2. Was supplied under pressure to pass through the internal space, and the dissolved oxygen concentration at the outlet 2b side of the gas dispersion device 2 was measured. The results shown in Tables 1 to 4 were obtained.

Here, in order to measure the removal rate of dissolved oxygen only in the gas dispersion device 2, it is necessary to measure the dissolved oxygen concentration with the treated water immediately after passing through the gas dispersion device 2. Therefore, the treated water in which bubbles discharged from the outlet 2b of the gas dispersion device 2 are dispersed and turbid is collected in a transparent column (not shown), and thereafter the bubbles in the treated water rise to be transparent. When the bottom side of the column became transparent, the dissolved oxygen concentration was measured by a dissolved oxygen concentration meter (not shown) arranged in advance at such a position.

[0064]

[Table 1]

[0065]

[Table 2]

[0066]

[Table 3]

[0067]

[Table 4]

The various symbols used in Tables 1 to 4 are shown below. V _R : Volume in gas dispersion device (cm ³ ) V _G : Flow rate of inert gas (liter / min) _VL : Flow rate of treated water (liter / min) T: Temperature of treated water (° C.) P : applied pressure of the water to be treated ^{(Kg / cm 2 G) d} B: cell diameter under average pressure in the gas distribution device 2 (μm) P _m: average pressure in the gas distribution device 2 (atm) C _0: Dissolved oxygen concentration of treated water (ppm) C: Dissolved oxygen concentration of treated water (ppm) θ _R : Residence time of mixed fluid in gas dispersion device 2 (s
ec) K _L a: Overall mass transfer coefficient (1 / sec)

From the above experimental results, the bubble diameter d _B of the inert gas under the average pressure P _m in the gas dispersion device 2 was 45.
It is recognized that the bubbles are formed into fine bubbles of about μm to 66 μm, which significantly increases the gas-liquid interface area, and the removal rate of dissolved oxygen is large even with a very short gas-liquid contact time of several seconds or less. It was confirmed.

[0070] Incidentally, the bubble cell diameter d _B in Table 1 to Table 4, the treated water discharged from the gas distribution apparatus 2 taken transparent column was determined from the rate of rise of bubbles in the transparent column at atmospheric pressure The diameter is calculated by converting it to a value under the average pressure P _m in the gas dispersion device 2.

[0071]

In summary, according to the present invention, the inlet 23 of the gas dispersion device 2 is connected to the treated water supply pipe 4 for supplying the treated water from which dissolved oxygen should be removed under pressure at atmospheric pressure or higher, and the treated water supply is performed. Inert gas injection pipe 7 for injecting an inert gas in the middle of the pipe 4.
Since the treated water discharge pipe 5 is connected to the outlet 24 of the gas dispersion device 2, the bubble diameter d _{B that} is made fine in the gas dispersion device 2 is under pressure in the gas dispersion device 2. Therefore, the diameter is smaller than that in the case of being open to the atmosphere, which is advantageous in increasing the gas-liquid interface area, and the bubble diameter d
_{Since B} is almost constant (about 55 ± 10 μm), the liquid flow rate that is easy to set when setting the removal rate of dissolved oxygen,
Since the removal rate can be easily set by adjusting the gas flow rate, the pressure, etc., the inside of the tank 9 is divided into the primary chamber 9a and the secondary chamber 9b by the partition wall 13 having only water permeability, and the treatment is performed. While connecting the water discharge pipe 5 to the primary chamber 9a,
Since the drainage pipe 12 is connected to the secondary chamber 9b, the movement of bubbles is stopped by the partition wall 13, so that the treated water discharged from the secondary chamber 9b is raw water or washing water without being turbid at all in the bubbles. Can be used as

The gas dispersion device 2 has an inlet 23 and an outlet at both ends.
Two large and small discs in which a cylindrical casing 21 having 24 and a plurality of cylindrical small chambers 27, 27a open frontward and having side walls 32 formed at right angles to the front faces are arranged on the front faces facing each other. 2
8 and 29 as a set, consisting of a plurality of gas dispersion elements 26 formed by concentrically superposing them, the large-diameter disc
28 is formed with an outer diameter that is watertight to the inner peripheral surface of the casing 21, a through hole 30 is formed in the center, and a small-diameter disk.
The outer diameter of 29 is sized so as to be separated from the inner peripheral surface of the casing 21 so that the flow passage 31 is formed between the outer peripheral surface and the inner peripheral surface of the casing 21, and the small chambers 27, 27a of the large-diameter disk 28, ... Small chambers 29, 27
are arranged in different positions so that the small chambers 27, 27a of each other communicate with the other small chambers 27, 27a of which the gas chambers 27, 27a are opposed to each other. Are arranged in the casing 21 so as to be adjacent to each other, and the inlet 23 and the outlet 24 of the casing 21 and the communication hole 30 are arranged.
Since the large diameter disks 28 are arranged on both sides so that they communicate with each other, the inflowing water to be treated and the inactive gas diffuse from the upstream side to the downstream side through the small chambers 27, 27a which communicate with each other. And the aggregates are sequentially flowed, and in the flow process, the side walls 32 of the small chambers 27, 27a ... Collide against the side surface and the upper end surface and the bottom surface at right angles, and the small chambers 27, 27a.
dispersion and merging into a ..., serpentine, and complex flow by a combination of vortex or the like, the bubble diameter d _B of the inert gas by the large variance total number, because it can significantly finer than conventional degassing tower a, Since the efficiency of removing dissolved oxygen is remarkably improved and the flow state is complicated as described above, the water to be treated is not discharged in a short circuit without contacting the inert gas, and the gas dispersion element The flow direction of diffusion and aggregation in 26 is a radial direction, and since it is complicatedly bent, the flow path length (residence time θ _R ) can be lengthened and the bubble diameter d _B can be reduced, so the gas dispersion device 2 Can be miniaturized.

Further, in the gas dispersion device 2, lids 25 and 25a having an inlet 23 and an outlet 24 formed at both ends of a cylindrical casing 21 are made detachable and are inserted into the casing 21 by an elastic body. A tubular body 35 is formed with an outer diameter, and this tubular body is
The collar pieces 36, 36a are integrally molded inward from both ends of 35 to form a ring-shaped annular seal body 37, and the ring-shaped seal body 37 has an outer diameter close to the inner peripheral surface of the tubular body 35. Large diameter disc 28
The outer diameter of the small-diameter circular plate 29 is formed so as to be separated from the inner peripheral surface of the tubular body 35 to form the flow passage 31 between the inner peripheral surface and the inner peripheral surface. Large diameter disks 28 on both sides of 37
Are arranged, and two small-diameter discs 29 are arranged in such a manner that the small chambers 27, 27a ... are arranged in different positions so that the small chambers 27, 27a ... communicate with a plurality of other small chambers 27, 27a ... which are opposed to each other. The gas dispersing and collecting element 38 is arranged in the casing 21, and the dimension L2 between both ends of the gas dispersing and gathering element 38 is set larger than the dimension L1 between both ends of the casing 21. , 25a can be attached to both ends of the casing 21 so that the gas dispersion collecting element 38 can be sandwiched and fixed, and in addition to the degassing effect similar to the above, the disks 28, 29
Since the close contact state of the upper end faces of the side walls 32 forming the small chambers 27, 27a, ... Can be firmly maintained, rattling of the discs 28, 29 can be prevented, and thus the upper end faces of the side walls 32 or the large disc 28. It is possible to prevent problems such as short-circuited flow caused by leakage from the outer peripheral side of the nozzle and defective dispersion and mixing due to pulsating flow.

Further, the inlets 23 are provided at both ends of the cylindrical casing 21.
The lid seats 25 and 25a having the outlet 24 and the outlet 24 are detachable, and a columnar projection 50 is provided to be inserted into the casing 21. 40, and the outer diameter of the large-diameter disk 28 is set to the casing 21.
The size of the small chamber 2
A seal seating surface 40 formed in a half shape is formed on the peripheral side of the rear surface where the 7, 27a ... Are not formed, and the small chambers 27, 27a of each other are formed.
So as to communicate with a plurality of other small chambers 27, 27a which face each other, the two large and small discs 28, 29 are connected to form a gas dispersion element 26.
Since 26 are arranged in the casing 21 so that the disks 28 and 29 having the same diameter are adjacent to each other, the seal member 55 is provided in the seal groove 54 defined by the adjacent seal seat surface 40. By simply inserting the sealing member 55 and the gas dispersion element 26 into the casing 21 one by one, the sealing groove 54
Can be defined and at the same time the seal member 55 can be installed in the seal groove 54, which simplifies the assembly of the gas dispersion device 2 and ensures that the seal member 55 is installed in the seal groove 54. By restricting the short and final flow of the fluid from the outer peripheral side of the circular plate 28, the mixing efficiency is prevented from lowering, the gas dispersion efficiency is kept good, and the seal seat surface 40 of the cylindrical protrusion 50 is Since the seal member 55 is mounted in the seal groove 54 defined by the seal seat surface 40 of the disc 28, the cylindrical protrusion
50 Leakage from the outer periphery to the outside can be prevented at the same time, and the cylindrical protrusion
50 Gaskets that are generally provided on the outer circumference are not required,
Moreover, since the outer diameter of the large-diameter disk 28 does not come into close contact with the inner peripheral surface of the casing 21, it is not necessary to make the processing accuracy of the inner peripheral surface of the casing 21 in which a plurality of gas dispersion elements 26 are arranged precise, Machining of 21 itself will be easy.

Further, since the seal seat surface 40, which is the bottom of the seal groove 54, is formed into a tapered surface, the tapered surface serves as a guide surface when the seal member 55 is mounted, and it is difficult to visually confirm the casing. This is a great practical effect in that a seal failure due to the biting of the seal member 55 in the inside 21 can be prevented.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a device for removing dissolved oxygen in water according to the present invention.

FIG. 2 is a schematic configuration diagram of another embodiment of the above removing device.

FIG. 3 is a schematic sectional view of a gas dispersion device.

FIG. 4 is a front view of two discs constituting a gas dispersion element of the above gas dispersion device.

FIG. 5 is a perspective view of the same disc.

FIG. 6 is a view showing a communication arrangement state of the small chambers when two discs are overlapped concentrically with each other.

FIG. 7 is a view showing a communication arrangement state in which the small chambers in the disc are triangular in shape.

FIG. 8 is a view showing a communication arrangement state in which the small chambers in the disc are formed in a square shape.

FIG. 9 is a view showing a communication arrangement state in which the small chambers in the disc are formed into octagons.

10 is a schematic cross-sectional view taken along the line AA of FIG.

FIG. 11 is a schematic cross-sectional view of a gas dispersion device using two large and small circular disks provided with protrusions.

12 is a schematic cross-sectional view taken along line BB of FIG.

FIG. 13 is a schematic cross-sectional view showing another embodiment of the gas dispersion device.

FIG. 14 is a cross-sectional view showing a state before the lid is mounted in the same gas dispersion device.

FIG. 15 is an exploded perspective view of a gas dispersion assembly element that constitutes the above gas dispersion device.

FIG. 16 is a schematic sectional view showing another embodiment of the gas dispersion device.

FIG. 17 is a front view of two large and small discs that constitute a gas dispersion element in the above gas dispersion device.

FIG. 18 is a side view of two large and small discs of the same.

FIG. 19 is a front perspective view of two large and small discs of the same.

FIG. 20 is a rear perspective view of the large-diameter disc of the same.

21 is a schematic cross-sectional view taken along the line CC of FIG.

22 is a schematic cross-sectional view taken along line DD of FIG.

FIG. 23 is an exploded perspective view of a gas dispersion element.

FIG. 24 is a perspective view of a gas dispersion element.

FIG. 25 is a partially enlarged cross-sectional view showing a mounting state of a seal member in a seal groove formed of a tapered surface.

FIG. 26 is a schematic structural view showing a conventional bubble column type dissolved oxygen removing means.

[Explanation of symbols]

 2 Gas disperser 4 Treated water supply pipe 5 Treated water discharge pipe 7 Inert gas injection pipe 9 Tank 9a Primary chamber 9b Secondary chamber 12 Drain pipe 13 Partition 21 Casing 23 Inlet 24 Outlet 25, 25a Lid 26 Gas dispersion element 27, 27a… Small chamber 28 Disc 29 Disc 30 Flow hole 31 Flow passage 32 Side wall 35 Cylindrical body 36, 36a Collar piece 37 Annular seal body 38 Gas dispersion collecting element 40 Seal seat surface 50, 50a Cylindrical protrusion 54 Seal groove 55 Seal member

Claims (5)

[Claims] 1. A large and a small cylinder having a cylindrical casing having an inlet and an outlet at both ends, and a large number of forward-opening cylindrical small chambers having side walls formed at right angles to the front faces which face each other. A set of discs, which are composed of a plurality of gas dispersion elements formed by concentrically superimposing the discs, and the large-diameter disc is formed with an outer diameter that is watertight with the inner peripheral surface of the casing, A circulation hole is formed in the center, and the outer diameter of the small-diameter disk is large enough to separate from the inner peripheral surface of the casing and form a flow path between the inner peripheral surface and the inner peripheral surface. The small chamber of the plate and the small chamber of the small-diameter disk are arranged in different positions so that the small chambers communicate with a plurality of other small chambers that face each other. So that they are stacked in the casing and arranged in the casing. Using a gas dispersion device configured by arranging large-diameter discs on both sides so that the outlet and the communication hole communicate with each other,
The water to be treated from which dissolved oxygen should be removed is pressure-fed at atmospheric pressure or higher from the inlet of the gas dispersion device, and flows through the gas dispersion device with an inert gas being pressed into the water being pressure-fed. A method for removing dissolved oxygen in water, which comprises: 2. A treated water supply pipe for supplying the treated water from which dissolved oxygen is to be removed at a pressure higher than atmospheric pressure to the inlet of the gas dispersion device, and an inert gas is provided in the middle of the treated water supply pipe. The inert gas press-fitting pipe to be press-fitted is connected, the treated water discharge pipe is connected to the outlet of the gas dispersion device, and the inside of the tank is divided into a primary chamber and a secondary chamber by a partition having only water permeability. While connecting the water discharge pipe to the primary chamber, connecting the drain pipe to the secondary chamber, the gas dispersion device is a cylindrical casing having an inlet and an outlet at both ends, and on the front surfaces facing each other,
A pair of large and small discs in which a large number of open front small cylindrical chambers whose side walls are perpendicular to the front face are arranged as a set, and are composed of a plurality of gas dispersion elements concentrically superposed. The large-diameter disc is formed with an outer diameter that is in water contact with the inner peripheral surface of the casing, a through hole is formed in the center, and the outer diameter of the small-diameter disc is from the inner peripheral surface of the casing. The small chamber of a large-diameter disk and the small chamber of a small-diameter disk are separated from each other by a size such that a flow passage is formed between them and the inner peripheral surface. The gas distribution elements are arranged in the casing so that discs having the same diameter are adjacent to each other and are arranged in the casing so that the inlet and outlet of the casing communicate with each other. Water with a large diameter disk on each side Apparatus for removing dissolved oxygen. 3. The gas dispersion device according to claim 2,
A cylindrical casing having an inlet and an outlet formed at both ends is detachable, and an elastic body forms a cylinder with an outer diameter that is inserted into the casing. A ring-shaped ring-shaped seal body is formed by integrally molding the flange piece, and a large-diameter disk is formed with an outer diameter that is in close contact with the inner peripheral surface of the cylindrical body of this ring-sealed body, and a small-diameter circle is formed. The outer diameter of the plate is set so as to separate from the inner peripheral surface of the cylindrical body to form a flow path between the inner peripheral surface and the inner peripheral surface, and large-diameter circular plates are arranged on both sides of the annular seal body. The small gas chambers are arranged in such a manner that two small circular discs are arranged so that the small chambers are located in different positions so that they communicate with a plurality of other small chambers facing each other. The elements are arranged in the casing, and the dimension between both ends of the gas dispersion collecting element is Apparatus for removing water dissolved oxygen, characterized in that the listening configuration. 4. The gas dispersion device according to claim 2,
A seal seat with a cylindrical casing that has an inlet and an outlet formed at both ends and is detachable, and has a columnar protrusion that is inserted into the casing, and is formed in a half-divided shape on the peripheral side of the tip of the columnar protrusion. The surface is formed, and the outer diameter of the large-diameter disk is formed so as not to be in close contact with the inner peripheral surface of the casing.
A seal seating surface is formed on the peripheral edge of the back surface where no small chamber is formed, and the two small and large sizes are used so that the small chambers are in different positions so that they communicate with other multiple small chambers facing each other. Discs are connected to each other to form a gas dispersion element, and these gas dispersion elements are arranged in a casing so that discs having the same diameter are adjacent to each other and are arranged in a casing. A device for removing dissolved oxygen in water, characterized in that a seal member is provided in the groove. 5. The gas dispersion device according to claim 4,
A device for removing dissolved oxygen in water, characterized in that a seal seat surface which is a bottom portion of the seal groove is formed into a tapered surface shape.