JP5595219B2 - Air lift pump - Google Patents

Description

  The present invention relates to an air lift pump for transferring a liquid mixture containing liquids and solids.For example, a pumping pipe is installed inside a tank such as a reaction tank in a sewage treatment plant, and the pumping pipe is formed above the pumping pipe. The present invention relates to an air lift pump in which a transfer flow path capable of transferring liquid or the like in a tank is connected, and an air supply port to which an air supply device can be connected is provided at the lower part of a pumping pipe.

An air lift pump is known as one of pumps for transferring a liquid or a mixed liquid containing a solid substance having a small particle diameter (hereinafter, simply referred to as “liquids”).
FIG. 5 shows an example of a conventional air lift pump.
In this air lift pump, a pumping pipe 3 having a predetermined inner diameter is placed in a tank 1 in which liquids 2 to be transferred are accommodated, and most of them are immersed in the liquids 2 and are erected. Yes.
Inside the tank 1, a conduit 4 is provided for blowing gas toward the pumped water pipe 3.
One open end 4a of the conduit 4 is connected to an air chamber 3a provided in the lower part of the pumping pipe 3, and the other open end 4b is connected to a gas supply source 8 such as a blower.
The air introduced into the air chamber 3 a enters the inside of the pumping pipe 3 through the air holes 3 b as the air feeding part provided on the outer peripheral part of the pumping pipe 3 and rises as bubbles 6.
Since the upper side of the air chamber 3a is a gas-liquid mixed fluid inside the pumping pipe 3, the static pressure of the air chamber 3a of the pumping pipe 3 is lowered, and liquids flow from the lower end of the pumping pipe 3, and the pumping pipe Ascend the inside of 3.
The upper part of the pumping pipe 3 is connected to a transfer channel 5 extending in the horizontal direction from the gas-liquid separation chamber 10 ′, and the liquid containing the bubbles 6 is separated into gas and liquids in the gas-liquid separation chamber 10 ′. The gas is discharged into the atmosphere, and the liquids flow in the horizontal direction in the transfer flow path and are discharged from the outflow path section 7.

This air lift pump has very few operating parts and the only one is, for example, a gas blowing mechanism for the inside of the pumping pipe 3 such as an air supply device, so that the structure is very simple and there are few failures. There are advantages.
The air lift pump having such advantages is used also as a return means from an aeration tank to an oxygen-free tank or a transfer means between other tanks in a reaction tank of a sewage treatment plant.

The conventional air lift pump has the above-mentioned advantages, but on the other hand, when the transfer channel 5 is a closed channel and there is a need to consider the prevention of bubbles remaining in the liquid to be transferred, a closed channel-shaped transfer channel is used. 5 must be provided with a gas-liquid separation chamber 10 ′ and a means for removing bubbles from the liquid. However, when the gas-liquid separation chamber 10 ′ is installed at a position higher than the liquid level of the tank 1. In spite of the purpose of the transfer, a large amount of power is required to raise the water level once, and the required power is increased for air input, resulting in low energy efficiency.
Conventionally, in the air lift pump, the gas-liquid separation chamber 10 ′ itself has to be large, and the size of the air lift pump has been increased.

Further, when the transfer channel 5 is a closed channel and the gas-liquid separation chamber 10 ′ is not provided, the liquid is transferred while including a large number of bubbles. Since the pipe resistance when the liquid containing bubbles flows is larger than the case of only the liquid, the flow rate of the liquid to be transferred becomes small relative to the amount of energy used for the input of air. As a result, there has been a problem that energy-saving operation cannot be performed.
Further, if the air is transferred as it is without removing the bubbles in the transfer flow path 5, a large amount of oxygen is supplied to the fluid in the transfer destination tank 1A. For this reason, the environment in the transfer destination tank changes aerobically, and when the transfer destination tank 1A is an anaerobic tank or an oxygen-free tank, adverse effects such as a decrease in water treatment performance occur.

In the air lift pump, when the transfer channel 5 is an open channel, in the process in which the gas-liquid mixed fluid flows through the transfer channel 5, the bubbles gradually move from the free surface of the liquids as the bubbles flow downstream with the liquids. Since the atmosphere was released, there was a merit that the gas-liquid separation chamber 1A became unnecessary.
However, if there is a civil structure such as a cross beam of the tank 1 in the middle of the transfer flow path 5, there is a disadvantage that the air lift pump cannot be applied. Because it depends on the shape of the material, there is a problem that it may not be applied.

  An object of the present invention is to provide an air lift pump that can solve all the problems of conventional air lift pumps, such as high energy efficiency and miniaturization of the apparatus.

In order to achieve the above object, an air lift pump of the present invention has a pumping pipe, an air input part provided in the pumping pipe, and a horizontal part for transferring a gas-liquid two-phase flow in a horizontal direction connected to the pumping pipe. a transfer passage, the air lift pump for transferring liquid such contained in the tank to so that a gas-liquid separation chamber for respectively separating the air and liquid such to the transport channel, the free surface of the liquid such transportation target contained in the tank, the so installation height of the upper end of the horizontal portion of the transfer channel and match, set up the transfer channel, the plane position of the pumping unit distance from to the upstream end of the cell opening for opening of the gas-liquid separation chamber, characterized in that the so that set so as to be 4-7 times the internal diameter of the riser pipe.

  In this case, a bend pipe having a radius of curvature of 1 to 2 times the inner diameter of the water pump pipe can be used at the connection portion between the water pump pipe and the transfer channel.

  Further, the gas-liquid separation chamber is configured by opening a slit-like opening having a length 3 to 7 times the inner diameter of the pumping pipe in the upper part of the cross section of the transfer channel, and providing an outer cylinder surrounding the opening on the outer periphery thereof. be able to.

  Further, a downcomer having an angle of 30 to 60 degrees can be provided on the downstream side of the gas-liquid separation chamber.

  Further, the inner diameters of the gas-liquid separation chamber and the downcomer can be set to 1.1 to 1.2 times the inner diameter of the pumped pipe.

  In addition, a second gas-liquid separation chamber is provided adjacent to the downstream side of the gas-liquid separation chamber, the second gas-liquid separation chamber is provided with a long hole-like opening in the upper cross section of the transfer channel, and the outer periphery thereof. An outer cylinder surrounding the opening can be provided in the part.

According to the air lift pump of the present invention, by matching the free surface in the tank and the installation height of the upper end of the horizontal portion of the transfer channel, compared to the case where the water level is higher than the liquid level in the tank, When the same amount of air is input, the driving force increases, and as a result, energy-saving operation is possible.
In addition, since the transfer channel is a closed channel, the transfer channel can be installed in tanks having various structures without depending on the shape of the civil engineering structure.

And by setting the distance from the plane position of the pumping section to the upstream end of the bubble opening of the gas-liquid separation chamber to be 4 to 7 times the inner diameter of the pumping pipe, the distance from the pumping pipe is set in the horizontal direction. The bubbles contained in the fluid with the changed flow gradually rise in the transfer flow path, and when removed from the opening of the gas-liquid separation chamber, most of the bubbles are gathered at the upper part. Air bubbles are efficiently removed without disturbing the flow of liquids concentrated on the liquid crystal. Therefore, the dimension of the opening length of the gas-liquid separation chamber can be shortened, and as a result, the volume of the main gas-liquid separation chamber can be reduced.

  Moreover, when a bend pipe having a radius of curvature of 1 to 2 times the inner diameter of the pumping pipe is used at the connection part between the pumping pipe and the transfer flow path, the rising direction of the gas-liquid two-phase flow changes in the horizontal direction. Therefore, energy saving operation is possible.

  In addition, an inclined down pipe of 30 to 60 degrees is provided on the downstream side of the gas-liquid separation chamber, and in particular, the inner diameters of the gas-liquid separation chamber and the down pipe are set to 1.1 to 1.2 times the inner diameter of the pumping pipe. As a result, the flow rate of the liquids is reduced, the bubbles are increased, and the bubbles are efficiently removed from the small openings.

In addition, the gas-liquid separation chamber has a slit-like opening in the upper cross section of the transfer channel, whose width is 0.05 to 0.2 times the inner diameter of the pumping pipe and whose length is 3 to 7 times the inner diameter of the pumping pipe. And an outer cylinder surrounding the opening is provided on the outer periphery thereof, and a second gas-liquid separation chamber is provided adjacent to the downstream side of the gas-liquid separation chamber, and the second gas-liquid separation chamber The volume of the gas-liquid separation chamber and the second gas-liquid separation chamber can be reduced by providing a long hole-like opening in the upper part of the cross section of the transfer channel and providing an outer cylinder surrounding the opening on the outer periphery thereof. Is possible.
Here, at the opening of the second gas-liquid separation chamber, bubbles that have passed through the following two systems are removed. The first channel is a small number of residual bubbles that are not removed in the gas-liquid separation chamber and continue to flow through the upper section of the transfer channel. In the second path, fine bubbles that remained slightly after the second gas-liquid separation chamber are initially lowered at the upper part of the cross section by the downcomer pipe on the downstream side of the second gas-liquid separation chamber. Then, they are lifted so as to flow backward in the upper part of the cross section, and are similarly removed from the opening of the second gas-liquid separation chamber.
As a result, there is almost no air bubbles in the downstream transfer flow path after the middle of the downcomer, and as a result, the flow resistance is reduced and energy saving operation is possible.

It is a general | schematic vertical sectional view which shows one Example of the air lift pump of this invention. It is an A arrow top view of FIG. It is B arrow sectional drawing of FIG. It is a graph which shows the measurement result of air supply amount and water supply amount. It is a schematic vertical sectional view showing a conventional air lift pump.

  Embodiments of an air lift pump according to the present invention will be described below with reference to the drawings.

  1 to 3 show an embodiment of the air lift pump of the present invention.

This air lift pump is similar to the conventional air lift pump shown in FIG. 5 in that a pumping pipe 3 having a predetermined inner diameter is contained in a tank 1 in which liquids 2 to be transferred are accommodated. It is immersed in 2 and is erected.
Inside the tank 1, a conduit 4 is provided for blowing gas toward the pumped water pipe 3.
One open end 4a of the conduit 4 is connected to an air chamber 3a provided in the lower part of the pumping pipe 3, and the other open end 4b is connected to a gas supply source 8 such as a blower.
The air introduced into the air chamber 3 a enters the inside of the pumping pipe 3 through the air holes 3 b as the air feeding part provided on the outer peripheral part of the pumping pipe 3 and rises as bubbles 6.
Since the upper side of the air chamber 3a is a gas-liquid mixed fluid inside the pumping pipe 3, the static pressure at the inlet of the pumping pipe 3 is lowered, and liquids flow from the lower end of the pumping pipe 3, and the pumping pipe 3 Rise inside.

  The air lift pump includes a pumping pipe 3, pores 3b as an air input portion, a transfer channel 5 for transferring a gas-liquid two-phase flow in the horizontal direction, and the air lift pump A gas-liquid separation chamber 10 for separating liquids from each other is provided, and the free surface in the tank 1 and the installation height of the upper end of the horizontal portion of the transfer channel 5 are made to coincide.

  Specifically, the transfer channel 5 that transfers liquids from the tank 1 to the other tank 1A through the tank wall of the tank 1 is a closed channel, and the water level is approximately the top of the horizontal portion 5a of the transfer channel 5. Arrange to match the part.

  In addition, a bend pipe 9 having an appropriate shape is provided above the pumping pipe 3 to change the direction of the pumping pipe 3 and the transfer flow path 5, and a gas-liquid separation chamber 10 and, if necessary, a second gas-liquid separation. The chambers 11 are arranged at appropriate positions, respectively, and each of the gas-liquid separation chambers 10 and 11 has an appropriate structure with a small volume, and the downstream side of the gas-liquid separation chamber 10 (when the second gas-liquid separation chamber 11 is provided) Is provided with an oblique downcomer 12 on the downstream side of the second gas-liquid separation chamber 11.

  In this case, a bend pipe having a radius of curvature of 1 to 2 times (in the present embodiment, about 1.5 times) an inner diameter of the pump pipe 3 for connection with the transfer flow path 5 is provided above the pump pipe 3. 9 is provided.

The position of the gas-liquid separation chamber 10 is such that the distance in the plane direction from the plane center position of the pumping pipe 3 to the slit start end of the gas-liquid separation chamber 10 is the inner diameter of the pumping pipe 3 (hereinafter abbreviated as “D”). The position is set to be 3 to 7 times (5.5 times in this embodiment).
FIG. 4A shows the measurement results of the air supply amount and the water supply amount when the slit position is changed to 2.35 times and 5.5 times D.
As shown in FIG. 4A, when the slit position is 5.5 times, the water supply amount is relatively large in the range of the air supply amount 0.17 to 0.43 m ³ / min.
A bend with a radius of curvature of 1.5D is provided at the top of the pumping pipe, and the slit position is 1.5D at the shortest. However, immediately after the bend, there are many bubbles other than the top of the pipe and they are not completely removed. However, when the length was increased to 5.5D, the residence time became longer, and the coalescence of bubbles progressed, and most of the bubbles were opened from the slit.
The second gas-liquid separation chamber 11 is located on the downstream side of the gas-liquid separation chamber 10, on the downstream side, and on the upstream side of the downcomer pipe 12, and as close to the top of the downcomer pipe 12 as possible. To do.

The gas-liquid separation chamber 10 has an inner diameter between the cylindrical portion 10a of the gas-liquid separation chamber 10 and the middle 12a of the downcomer pipe that is larger than the pumping pipe 3 (in this embodiment, 1.1 to 1.2 times D). ), And other pipes are connected by a tapered pipe 13 whose diameter changes gently.
The gas-liquid separation chamber 10 has a width of 0.05 to 0.2 times D (about 1/10 in this embodiment) and a length of 3 to 3 at the top of the cross section of the transfer channel 5. The slit-shaped opening 10b is provided 7 times (in this embodiment, about 5 times).
Experimental data are shown in FIG. 4 (b) and FIG. 4 (c).
4B shows the case where the slit width is changed to 0.1 times and 0.6 times D, and FIG. 4C shows the case where the slit length is changed to 2.0 times and 4.6 times D. Shows the measurement results of air supply and water supply.
As shown in FIG. 4B, when the slit width is 0.1 times D, the water supply amount is larger in the range of the air supply amount 0.17 to 0.35 m ³ / min.
Moreover, as shown in FIG.4 (c), when the slit length is 4.6 times of D, a water supply amount is larger in the range of air supply amount 0.17-0.43 m < ³ > / min.
This is considered to be due to the fact that the water flow is less disturbed and there are few remaining bubbles.
Further, the gas-liquid separation chamber 10 is provided with a rectangular column duct 10c which is an outer cylinder surrounding the outer periphery of the opening 10b on the outer periphery thereof, and the rectangular column duct 10c is provided with a guide plate 10d on the upper side of the opening 10b. And

  The second gas-liquid separation chamber 11 has a structure in which a long hole-like opening 11a is provided in the upper portion of the cross section of the transfer flow path 5, and a rectangular or circular outer cylinder 11b surrounding the opening 11a is provided on the outer periphery thereof.

  The downcomer 12 has a structure provided at an angle of 30 to 60 degrees (45 degrees in this embodiment) on the downstream side.

  The air lift pump of the present invention has been described above based on the embodiments thereof. However, the present invention is not limited to the configurations described in the above embodiments, and the configuration is appropriately changed without departing from the spirit of the present invention. It is something that can be done.

  Since the air lift pump of the present invention has characteristics of high energy efficiency and miniaturization of the apparatus, it is widely used for applications of an air lift pump for transferring a liquid mixture containing liquid or solid matter. it can.

1 tank 1A tank 2 liquids 3 pumping pipe 3a air chamber 3b pores (air input part)
4 Conduit 4a Open end of conduit 4b Open end of conduit 5 Transfer channel 6 Bubble 7 Outflow channel 8 Air supply source 9 Bend tube 10 Gas-liquid separation chamber 10a Cylindrical portion of gas-liquid separation chamber 10b Slit-shaped opening 10c Square pillar Duct 10d Guide plate 11 Second gas-liquid separation chamber 11a Long hole-shaped opening 11b Outer cylinder 12 Downcomer pipe 12a In the middle of the downcomer 13 Taper pipe

Claims (6)

A pumping pipe, an air input part provided in the pumping pipe, a transfer channel having a horizontal part for transferring a gas-liquid two-phase flow in a horizontal direction connected to the pumping pipe, and air and liquids in the transfer channel an air lift pump for transferring the liquid compound contained in the bath was so that a gas-liquid separation chamber for each separating bets, liquid such transportation target contained in the tank and the free surface, the so installation height of the upper end of the horizontal portion of the transfer channel and match, set up the transfer channel, to the upstream end of the cell opening for opening of the gas-liquid separating chamber from the plane position of the pumping unit air lift pump, characterized in that the distance has to so that set so as to be 4-7 times the internal diameter of the riser pipe.   2. An air lift pump according to claim 1, wherein a bend pipe having a radius of curvature of 1 to 2 times the inner diameter of the water pump pipe is used at a connecting portion between the water pump pipe and the transfer flow path. The gas-liquid separation chamber is constructed by opening a slit-like opening 3 to 7 times the inner diameter of the pumped pipe in the upper section of the transfer channel, and providing an outer cylinder surrounding the opening on the outer periphery. air lift pump according to claim 1 or 2 wherein. Air lift pump according to claim 1, 2 or 3, wherein in that a downcomer oblique 30-60 ° on the downstream side of the gas-liquid separation chamber. 5. The air lift pump according to claim 4 , wherein the inner diameters of the gas-liquid separation chamber and the downcomer are set to 1.1 to 1.2 times the inner diameter of the pumping pipe. A second gas-liquid separation chamber is provided adjacent to the downstream side of the gas-liquid separation chamber. air lift pump according to claim 1, 2, 3, 4 or 5, wherein in that which is configured by providing an outer tube surrounding the opening.

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