JPS5820294B2 - Gas-liquid mixing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for mixing a liquid and a gas, and more particularly to an apparatus for mixing a gas with water in, for example, a water treatment process.

Aeration equipment is used when treating water with the purpose of increasing the amount of dissolved oxygen Do in the water.

Dissolved oxygen is necessary for fish and other aquatic life to survive.

Dissolved oxygen is also necessary to prevent the production of unpleasant odors and to break down organic matter in the water.

Biochemical oxygen demand (BOD) is a measure of the amount of oxygen consumed during the biological process of decomposing organic matter in water.

A high BOD indicates that a large amount of organic waste is present and therefore a large amount of dissolved oxygen is required.

Aeration devices are particularly effective in increasing the amount of dissolved oxygen and, therefore, in creating high BOD conditions.

There are broadly two types of aeration equipment used for wastewater treatment.

That is, there are the diffused air type and the mechanical type.

Diffusion air type aeration systems introduce air or pure oxygen into the water through a submerged porous diffuser or nozzle device.

Mechanical aeration equipment stirs water to increase the dissolution rate of air introduced from the atmosphere.

Mechanical aeration systems are further divided into surface aeration systems and turbine aeration systems.

Surface aeration equipment uses an impeller that is either fully submerged or only partially submerged in water, and the impeller actively stirs the water to incorporate air into the water. A rapid change occurs between the interfaces.

Turbine aerators generally use a rotating impeller that is placed a distance below the surface of the water to be treated.

A dolaret tube is installed coaxially with the rotation axis of the impeller and supplies air to the liquid near the impeller.

The present invention is an apparatus for mixing a gas with a liquid such as water.

The device consists of a hollow outer tube member and a hollow inner tube member coaxially housed within the outer tube member.

The inner tube member is mounted for rotation within the hollow interior of the outer tube member.

A motor arrangement is mounted near a first or trailing end of the outer tube member and rotationally coupled to the first or trailing end of the inner tube member.

The inner tube member is formed with a projecting tube portion that projects forwardly and outwardly from the second or forward end of the outer tube member.

A propeller is attached to the front end portion of the inner tube so that the propeller rotates integrally with the inner tube member.

The propeller is mounted submerged in the liquid, and when the propeller rotates, it propels the liquid forward.

Further, a gas inlet is provided in the inner tube so that gas can flow into the hollow interior of the inner tube member.

A diffusion tube is configured as part of the inner tube member and extends forwardly and outwardly of the propeller.

The diffusion tube has a hollow interior that forms part of the hollow interior of the inner tube member.

The diffusion center also has an outwardly opening opening for injecting gas through the hollow interior of the inner tube member into the liquid in the area where the propeller is submerged.

The length of the diffusion tube is at least 50 mm the outer diameter of the propeller.
% length.

In a preferred embodiment, a housing is formed surrounding the motor, and an inlet gas chamber is formed around the motor, which is an annular space.

A hole is provided in the rear end surface of the housing to introduce gas, that is, air, into the introduction gas chamber.

The air drawn into the introduction gas chamber then flows into the hollow interior of the inner tube member and is then injected into the rotating liquid of the propeller.

The air injected into the liquid is thus preheated as it passes through the motor.

An anti-eddy current shield covering a portion of the outer circumferential surface of the outer tube member is attached to the outer surface of the outer tube member adjacent the propeller.

The shield is provided to prevent the formation of vortices in the liquid during rotation of the propeller.

If a vortex is generated while the propeller is rotating, gas or air will be mixed into the liquid, reducing propeller efficiency.

The inner surface of the inner tube member is formed with a cylindrical wall and aligned with its central axis with a tolerance dimension of substantially less than 0.381 mm (0.015 inch) along the entire length of the cylindrical wall. There is.

The rear end of the inner tube member is connected to the rotary drive shaft of the motor via a universal joint for flexible movement.

In conjunction with the precise alignment tolerances of the cylindrical wall, the use of universal joints reduces the occurrence of vibration effects and shear failure of the internal tube members.

The present invention will be described in detail below with reference to the drawings.

Gas-liquid mixing device 1 for mixing gas and liquid shown in Fig. 1
The front end portion of 0 is submerged in liquid 12.

Liquid 12 is typically waste liquid or sewage into which oxygen is injected.

Generally, the surrounding atmosphere is used as the gas, but this air is dissolved in the liquid 12 in the form of a large number of bubbles 14.

This device is designed as a portable device.

The device 10 is supported on the mount 15 using suitable fasteners 16 to an arm member 18 extending from a portable mount 15, and is placed in the liquid 12 at an angle of 20° with respect to the horizontal. It is supported in a partially submerged state.

The inclination angle of 20° was selected as an appropriate inclination angle between the horizontal and vertical directions, and when using this device, an inclination angle of approximately 22° from the horizontal is recommended when treating shallow marshes. It was particularly sufficient.

The device 10 of the present invention includes an outer tube member 22 and an inner tube member 24, as shown in FIG.

The outer tube member 22 includes an intermediate tube 26, a motor adapter 28 attached to a first or rear end of the intermediate tube 26, and an inner tube tube bearing housing 30 attached to a second or forward end of the intermediate tube 26. Consists of.

The inner tube member 24 includes an elongated tube 32 extending in the longitudinal axis direction, a propeller tube 34, and a diffusion tube 36.
It consists of

The propeller tube 34 has a forward end portion 38 having an outer diameter smaller than the inner diameter of the forward end 40 of the elongated tube 32, as shown in FIG.

This forward end portion 38 is then fitted within the tube 32 and secured thereto in any suitable manner, such as by welding.

As shown in FIG. 3, the outer diameter of the front end 42 of the propeller tube 34 is equal to
smaller than the outer diameter of

Therefore, the shoulder portion 4 is located at the seam between the front end portion 42 and the intermediate portion 44.
6 is formed.

The propeller 48 is therefore located at the front end portion 42 and abuts against the shoulder 46.

An internal thread is provided inside the rear end of the diffusion tube 36, and the diffusion tube 36 is fitted and fixed to the external threaded portion of the propeller tube 34.

Therefore, the internal thread of the diffusion tube 36 allows the propeller 4
8 is held on the propeller tube 34, and the propeller 4
8 is located between the shoulder 46 and the diffusion tube 36 and the frictional clamping is fixed by force.

As shown in FIGS. 6 and 7, the motor adapter 28 is formed with a cylindrical portion 50 and a frusto-conical portion 52, and the frusto-conical portion 52 is formed with a first conical portion 54 and a second conical portion. 56.

A plurality of ribs 58 are provided on the second conical portion 56.

A plurality of support arms 60 extend radially outwardly from rib 58.

A bundle 62 also extends outwardly from motor adapter 28.

Bundle 62 is used to adjust the position of device 10 or as a gripping member for the device during transportation.

The innermost inner hole 6 in the support arm 60 shown in FIG.
4 to attach the motor 61.

A housing 66 is also attached using an external hole 68 in the support arm 60.

As shown in FIG. 2, the housing 66 is formed from a cylindrical outer peripheral wall 70 and a rear end wall 72 that completely surround the motor 61. As shown in FIG.

There are a plurality of holes or long grooves 74 in the rear end wall γ2.

The slot or hole 74 is an inlet for air drawn into the interior of the housing 66.

An annular introduction gas chamber 78 surrounding the motor 61 is formed between the housing 66 and the motor 61 .

The motor 61 has a fan unit 80 for cooling the motor 61, and this unit is a fan for introducing air across the outer peripheral surface of the motor 61.

The movement of gas or air flowing through the inlet gas chamber 78 is indicated by arrows 76.

The air passing through the introduced gas chamber 78 is heated by the motor 61.

Air flows down from the introduction gas chamber 7B into the hollow interior of the motor adapter 28.

The motor adapter 28 also forms an enclosed space in which air is forced to flow forwardly within the hollow interior of the outer tube member 22.

An intake device such as an elongated air inlet 82 is provided at the rear end of the tube 32.

As indicated by arrow 84 in FIG.
The heated air flowing down the hollow interior of the inner tube member 24 flows through the long groove-shaped air inlet 82 into the hollow interior of the inner tube member 24 .

Although only one air inlet 82 is shown in FIGS. 2 and 4, it is preferred that at least two air inlets 82 be provided around the inner tube 32.

Accordingly, the heated air passes downstream through the inner tube member 32 and is injected outwardly from the open end of the diffusion tube 36, as described below.

Inner tube member 24 is connected at its aft end by a flexible joint, such as universal joint 86, and is supported within outer tube member 22.

The front end of the inner tube member 24 is supported by a water bearing 88 secured within the tube bearing housing 30 as shown in FIG.

The universal joint 86 connects the rotary drive shaft 90 that is rotationally driven by the motor 61 and the rear end of the internal tube member 32.
The water supply bearing 88 is provided so that the entire inner tube member 24 rotates and is lubricated.

The universal joint 86 has a crosshead 98 as shown in FIG.
The rear yoke 9 is connected to the front yoke 96 by
There are 4.

The rear yoke 94 has a head portion 100 having a central hole 102 therein.

The rotary drive shaft 90 of the motor 61 is fitted and fixed inside the hole 102, and the rotation of the rotary drive shaft 90 can be transmitted to the universal joint 86.

The rear yoke 94 has a pair of opposing arms 104 and 106.
There is.

As shown in FIG. 11, the aum 104 has a hole 109 passing through it, and the aum 106 has a hole 111 passing therethrough.

Crosshead 98 has a first pin having opposite end portions 113 and 115.

The end 113 is pivotally supported in the hole 109 and the end 1
15 is pivotally supported in hole 111.

The forward yoke 96 has a head portion 110 having a hole 112 therethrough.

The rear end of the tube 32 is fixed in the hole 112 and transmits rotation of the front yoke 96 to the tube 32.

The front yoke 96 also has a pair of opposing arms 114 and 11.
There are 6.

The arm 114 has a hole 118 therethrough, and the arm 11
6 has a hole 120 therethrough.

Crosshead 98 has a second pin with opposing end portions 122,124.

End portion 122 is pivotally supported within bore 118;
End portion 124 is pivotally supported within bore 120.

Clip 128 has end portions 113, 115, 122°12
4 in their respective holes 109, 111, 118°, 120.

The forward yoke 96 and the rear end of the inner tube member 32 attached thereto are therefore at the 130° 130° lateral axis of each pin.
32 enclosures can be moved in a pivoting manner.

The universal joint 86 allows the rear end of the inner tube member 32 to be flexible and freely rotated, and transmits rotation from the rotary drive shaft 90 to the inner tube member 32 .

As shown in FIG. 12, water bearing 88 has a plurality of bearing rod members 134 extending along its length.

The bearing rod members 134 are arranged on a pedestal such that there is a gap 136 between adjacent rod members 134.

When the water bearing 88 is placed in a liquid, such as water, water can flow into the gap 136 and also between the outer circumference of the propeller tube 34 and the bearing rod member 134.

The water therefore acts as a lubricant between the propeller tube 34 and the water supply bearing 88.

Inner tube member 32 is mechanically linearly formed with precise dimensional tolerances.

The inner tube member 32 has a diameter of 0.381.
With a tolerance dimension of less than im (0.015 inches), it is straightened so as to have a radius 140 relationship with respect to the axis 192 as shown in FIG.

That is, the radius 140 is within a tolerance of 0.015 inches or less over the entire length of the inner tube member 32.

The inner tube 32 is exactly 0.381 m7n (0,015
It has been found that when the inner tube member 32 is straightened to a tolerance dimension (inch), vibrations and whirring vibrations occur in the inner tube member 32, causing premature failure of the tube.

Alternatively, if the internal tube member 32 is straightened to a tolerance of 0.25 mm (0.01 inch) and the tube shaft system is dynamically balanced to an unbalance of 709 gr-mm 1 oz-inch at every 3450 revolutions. It has been found that the problem of vibration of the inner tube member 32 can be essentially eliminated.

It was determined that the vibration problem could be eliminated or alleviated by straightening the tube to a tolerance size significantly less than 0.381 inches (0.015 inches).

The use of a flexible joint, such as universal joint 86, and the critical tolerance dimensions described above help eliminate vibration.

A vibration problem found in aerators of the type described herein is a problem that can result in shearing or failure of the internal tube members after short periods of operation.

A plurality of fins 142 extend radially outwardly from the tube bearing housing 30 as shown in FIG.

Each fin 142 has a tip 144 and an anti-eddy current shield 146 is attached to a plurality of tips 114 of the fin 144.

The anti-eddy current shield 146 has a length that extends parallel to the axis 192 and a circumferential arcuate dimension that extends in an arc of less than 360 degrees.

As shown in FIGS. 2 and 3, the anti-eddy current shield 14
6 has a leading edge 148 that is generally truncated.

A portion of leading edge 148 extends above propeller 48 .

The shield 146 prevents the generation of vortices in the liquid near the propeller when the propeller rotates.

Without the shield 146, a vortex of liquid would occur in the immediate vicinity of the propeller, reducing the propulsion efficiency of the propeller to push liquid out.

The operation of the apparatus of the present invention will be explained below.

The device 10 is placed in the liquid 12 at an angle of inclination of 20 degrees to the horizontal.

Liquid 12 is typically sewage sewage or wastewater that contains organic matter and requires large amounts of dissolved oxygen.

The motor 61 is rotationally driven by a power source (not shown).

The rotary drive shaft 90 of the motor 61 rotates, and the rotation is transmitted to the inner tube member 24.

The propeller 48 rotates in the liquid 12 and also propels the liquid 12 by the open end of the diffusion tube 36, causing air to flow down through the hollow interior of the inner tube member 24 by a Venturi or suction effect.

Air drawn through the hollow interior of the inner tube member 24 is preheated while passing through an inlet air chamber 78 around the motor.

Preheating the air is preferred when using the device as an underwater aerator in northern regions where the water freezes in the winter.

By using preheated air, at least a portion of the water can be kept free and not frozen.

Therefore, the unfrozen portion of the water comes into contact with the outside air, allowing the air to be dissolved in the water.

If water is completely frozen, such contact between air and water is no longer possible.

The length of the diffusion tube 36 is at least 50% of the outer diameter dimension of the propeller 48.

The outer diameter dimension of the propeller 48 is indicated by line 150, and the line 15
0 is perpendicular to axis 192 and in the plane of rotation of the propeller.

The air bubble 14 is optically separated from the propeller 48 using a diffusion tube 36 sized such that it extends toward the forward side of the propeller by at least 50% of the outer diameter dimension 150 of the propeller 48. The liquid 12 is discharged into the liquid 12 at the position shown in FIG.

The propeller 48 will therefore be rotated in a liquid free of air bubbles 14.

This increases the efficiency of propeller 48 in propelling liquid 12.

If the diffusion tube 36 is too short, air bubbles 14
is discharged too close to the propeller, thereby mixing with the liquid propelled by propeller 48.

These conditions result in less liquid being propelled by the open end of the diffusion tube 36, resulting in poor aeration efficiency.

127mm with 76mm (3 inch) propeller tube
It turned out that it would be satisfactory if a (5 inch) propeller was used.

A curved internal curved surface 3 is provided at the open end of the diffusion tube 36.
There are 9.

Although the reason is unclear in FIG. 3, the air bubbles 14 are diffused over a wider area if the inner surface of the open end of the diffusion tube is curved than if it is straight. I understand.

As mentioned above, the anti-vortex shield 146 prevents swirling of liquid in the area adjacent the propeller 48 and increases the efficiency of the system.

If the device 10 is placed in the liquid 12 in which the propeller 48 is rotated with an inclination angle of 20°, a large positive area of the liquid 1
This helps in dispersing the air bubbles 14 over the air bubbles 14.

What is shown is merely an example, and the shape, size, and arrangement of parts may be changed.

[Brief explanation of the drawing]

Fig. 1 is a side view showing the device of the present invention placed in a liquid, Fig. 2 is a partial side view showing a part of the device of the present invention in cross section, and Fig. 3 is a front view of the lower end of the device of the present invention. Enlarged cross-sectional view of the end,
Figure 4 is an enlarged view of the universal joint attached to the rear end of the internal tube member, Figure 5 is a front view of the end of the motor adapter, and Figure 6 is a front view of the end of the motor adapter.
The figures are a sectional view taken along the line 6-6 in FIG. Figure 9 is a front view of the front end corresponding to the lower end of the device of the present invention;
11 is a sectional view taken along line 11-11 in FIG. 4, and FIG. 12 is a sectional view taken along line 12-12 in FIG. 1. are shown respectively. 10... Gas-liquid mixing device, 12... Liquid, 22... External tube member, 24...
・Internal tube member, 28...Motor adapter, 34...Propeller tube, 36...
・Diffusion tube, 38... Rear end, 42...
...Front end, 48...Propeller, 52...
・Truncated conical part, 66...Housing, 78...
...Introduction gas chamber, 82...Air inlet, 8
6... Universal joint, 88... Water supply bearing,
90... Rotation drive shaft, 146... Eddy current prevention shield.

Claims (1)

[Scope of Claims] 1. A longitudinal axis extends between the front and rear ends of an outer tube member including a hollow interior, and the front and rear ends of an inner tube member also forming a hollow interior. a longitudinal axis extending therebetween, the inner tube member being rotatable about the longitudinal axis within the outer tube member, and a motor facility adjacent the rear end of the outer tube member; The motor shaft is connected to the rear end of the inner tube member to enable rotation of the inner tube member, and the front end of the inner tube member is opened forward and outward, and the front end of the outer tube member is connected to the motor shaft. A propeller is attached to the tube portion projecting forwardly and outwardly beyond and is rotatable together with the inner tube member, adapted to propel the liquid by its rotational action when the propeller is placed in the liquid; A gas inlet is formed in the inner tube member wall to allow gas to be introduced from the outside into the hollow interior of the inner tube member, and an outer tube is formed on the outer surface of the outer tube member near the forward end thereof above the propeller. A gas-liquid mixing device that is provided with an anti-vortex shield that partially covers the circumferential surface of a member to prevent the occurrence of swirl around the propeller when the propeller rotates. 2. The device according to claim 1, wherein a plurality of fins are provided on the outer circumferential surface of the outer tube member near the front end thereof and protrude in the radial direction, and the fins are provided at a predetermined distance from the outer tube member. the inner surface of the shield member is bonded to the leading edge;
This provides a gas-liquid mixing device in which the shield member is attached to the outer surface of the outer tube member while maintaining a predetermined spatial distance. 3. The device according to claim 2, wherein the eddy current prevention shield defines a length of a constant dimension in the longitudinal axis direction of the outer tube member to define both ends thereof, and has a diameter of 36σ.
A gas-liquid mixing device formed by a circumferential dimension extending in an arcuate manner with a smaller angular range, and in which the front edge of the shield located near the propeller is cut into a truncated V-shape. 4. In the device according to claim 1, a diffusion tube is protruded from the front outer end position of the propeller and is formed to constitute a part of the inner tube member, so that the hollow interior of the diffusion tube is formed in the middle tube. It is constructed as a part of the hollow interior of the inner tube member, and its front opening end forms an injection port for injecting gas flowing down the hollow interior of the inner tube member toward the liquid in which the propeller is buried, and further includes the diffusion tube. A gas-liquid mixing device configured such that its length is at least 50% of the outer diameter of the propeller. 5. The device according to claim 1, wherein a plurality of support arms extend radially from the outer peripheral surface of the outer tube member at the rear end thereof, and a motor and a drive protruding from the motor. Equipped with motor equipment including a rotating shaft,
A motor is attached to the support arm, and the rotational drive shaft of the motor is arranged substantially linearly with the axis of the inner tube member so as to be rotatable about the axis, and the motor drive shaft is rotated by the inner tube member. A joint member for freely coupling is interposed between the two members, and the rotary motion of the motor drive shaft is transmitted to the inner tube member so as to allow flexible free movement at the rear end of the inner tube member. gas-liquid mixing device. , 6. The device according to claim 5, wherein a housing surrounding the motor is attached to the outer tube member near the rear end of the outer tube member, and an inlet gas surrounding the motor is provided inside the housing. A chamber is formed;
Further, an introduction opening is formed in the housing for introducing external gas surrounding the housing into the introduction gas chamber,
Furthermore, the inlet gas chamber is configured to communicate between the inner chambers of the outer tube member as well as with the gas inlet of the inner tube member, so that the gas flow passing through the inlet gas chamber is heated by the motor, and then A gas-liquid mixing device configured to flow out into the hollow interior of an inner tube member. 7. The apparatus of claim 1, wherein the inner tube member has an inner wall formed along its central axis along its entire length with a tolerance of 0.254 mm (0.01 inch). formed as a tubular body consisting of a cylindrical tube wall, and the tubular body is formed over most of the length of the inner tube member,
Further, near the front end of the outer tube member, a motor equipment including a motor attached to the member and a rotary drive shaft protruding from the motor is provided, and the drive rotation shaft of the motor and the rear end of the inner tube member are connected by a universal joint. A gas-liquid mixing device, wherein the rear end of the inner tube member is configured to be continuously rotatable and driven, and the rear end of the inner tube member can be flexibly and freely moved at the joint position.