An oxygen gas lift oxygen enrichment system

Abstract

The present invention discloses an oxygen gas-lift aeration system for aquaculture water bodies, which includes an air pump for circulating oxygen, an air pipeline for conveying oxygen, an air source for providing oxygen, an aeration head, an aeration water-pushing pipeline, and an air storage chamber; wherein the aeration water-pushing pipeline further includes an air inlet and water inlet pipe section, an air collecting pipe section, and an outlet pipe section, the air inlet and water inlet pipe section and the outlet pipe section are both located below the water surface, and the aeration head is arranged within the air inlet and water inlet pipe section; the air storage chamber is at least partially located above the water surface, is connected to an oxygen gas source for providing oxygen, and is connected to the air collecting pipe section and / or the outlet pipe section. The oxygen gas-lift aeration system of the present invention adopts oxygen aeration, and the oxygen can be recycled and reused, so that the utilization rate of oxygen is greatly improved.

Description

Technical Field

[0001] The present invention relates to an oxygenation system for aquaculture water, and more particularly to an oxygen gas lift type oxygenation system for aquaculture water. Background Art

[0002] Dissolved oxygen is a crucial parameter in water treatment systems for aquaculture, sewage treatment, and other applications. Higher dissolved oxygen levels can effectively eliminate harmful substances such as ammonia nitrogen, nitrite, and hydrogen sulfide, thereby improving water quality and increasing feed conversion rates.

[0003] With advancements in aquaculture technology and increasing stocking densities, traditional air aeration methods are increasingly unable to meet oxygenation needs. For example, the closer dissolved oxygen levels get to saturation, the harder it is to increase. At 30°C, the saturated dissolved oxygen level is only 7.56 mg / t. This makes it difficult to maintain dissolved oxygen levels above 5 mg / t over the long term using air aeration alone, and the level fluctuates significantly between day and night. Consecutive rainy days can lead to severe oxygen deficiency, potentially killing fish and shrimp.

[0004] Oxygen enrichment has the advantages of being fast, efficient, and able to achieve dissolved oxygen levels that cannot be achieved by air enrichment (such as supersaturation). The only disadvantage is the high cost of oxygen, so the utilization rate of oxygen is the key to oxygen enrichment. Currently, there are three main methods for oxygen enrichment in the existing technology:

[0005] (1) Aeration head aeration: This method must use extremely small micropores to increase the utilization rate of oxygen. Usually, a pressure of more than 100kPa (one atmosphere) is required. Even so, the utilization rate of oxygen is still difficult to exceed 30%;

[0006] (2) Jet: This method uses the Venturi principle: the negative pressure generated by high-speed water flow draws oxygen into the pipe, while intensely stirring and shearing it into fine bubbles. Its technical characteristics are that the faster the flow rate, the smaller the bubbles produced, and the higher the oxygen utilization rate, but at the same time, the energy consumption also increases;

[0007] (3) Micro-exposure machine: Due to its high cost and energy consumption, it is rarely used.

[0008] However, all of the above methods do not completely solve the problem of low oxygen utilization rate caused by the release of oxygen bubbles into the atmosphere after bursting.

[0009] Therefore, it is necessary to provide an oxygen enrichment system that can recycle unused oxygen. Summary of the Invention

[0010] The object of the present invention is to provide an oxygen gas-lift oxygenation system for use in aquaculture water bodies, which can improve oxygen utilization efficiency. The oxygen gas-lift oxygenation system collects oxygen bubbles that are not absorbed by the water body in an air storage chamber and reuses them for water oxygenation together with fresh oxygen from an oxygen source, thereby improving oxygen utilization efficiency and reducing oxygenation costs.

[0011] To achieve the above-mentioned purpose of the present invention, the present invention discloses an oxygen gas-lift type oxygenation system for aquaculture water bodies, the oxygen gas-lift type oxygenation system comprising an air pump for circulating oxygen, an air delivery pipe for delivering oxygen, an oxygen source for providing oxygen, at least one aeration head for forcibly transferring gaseous oxygen in the oxygen to liquid water in the water body, and at least one aeration water-pushing pipe supported by a float; the air delivery pipe delivers oxygen to the aeration water-pushing pipe through the aeration head;

[0012] Wherein, the oxygen gas lift type oxygen enrichment system further comprises at least one gas storage chamber;

[0013] The aeration water pushing pipeline used further includes an air inlet and water inlet pipe section, an air collecting pipe section, and a water outlet pipe section; wherein the air inlet and water inlet pipe section and the water outlet pipe section are both located below the water surface, and the air collecting pipe section connects the air inlet and water inlet pipe section and the water outlet pipe section and is located above the two, that is, closer to the water surface or partially above the water surface;

[0014] The aeration head is arranged in the air and water inlet pipe section, and the oxygen pumped by the air pump is aerated in the air and water inlet pipe section;

[0015] At least one gas storage chamber is at least partially located above the water surface, is connected to an oxygen source for providing oxygen, and is connected to the gas collecting pipe section and / or the water outlet pipe section.

[0016] In the oxygen gas-lift aeration system of the present invention, oxygen aeration is carried out in a closed environment. In this closed environment, oxygen bubbles are concentrated toward the gas collecting pipe section under the action of buoyancy, and gather at the top of the gas collecting pipe section, and enter the air storage chamber, and are used for further aeration together with fresh oxygen from the oxygen source, that is, they are pumped back to the aeration water push pipe by the air pump. In this way, most of the oxygen that is not absorbed in the air and water inlet pipe sections is recycled, which greatly improves the utilization rate of oxygen. A small amount of oxygen bubbles will flow through the water outlet pipe section under the action of thrust and enter the water body through the water outlet. Since the water outlet is usually located at the lower part of the water body, or even at the bottom, these small amounts of oxygen bubbles are retained in the water body for a long time under the action of water pressure, and some of them are absorbed by the water body.

[0017] As a preferred embodiment of the present invention, in the oxygen gas-lift oxygenation system of the present invention, a portion of the gas collection pipe section is located below the water surface and a portion is located above the water surface. More preferably, an oxygen recovery pipe is provided between the gas collection pipe section and the gas storage chamber to transport oxygen collected by the gas collection pipe section to the gas storage chamber, thereby improving oxygen utilization.

[0018] In the oxygen gas-lift aeration system of the present invention, the gas collection pipe section can also be placed completely below the water surface. If the gas collection pipe section is placed completely below the water surface and connected to the aforementioned gas storage chamber, oxygen bubbles can enter the gas storage chamber directly, releasing oxygen, which is then used for further aeration along with fresh oxygen from the oxygen source. In this manner, the gas collection pipe section can become part of the gas storage chamber.

[0019] To further improve oxygen utilization, an oxygen recovery pipe connected to the gas storage chamber can be installed in the water outlet pipe section, particularly near the water outlet. This allows oxygen bubbles that reach this location to float up into the gas storage chamber, releasing oxygen and further increasing oxygen utilization. Alternatively, the water outlet pipe section can be directly connected to the gas storage chamber, while the gas collection pipe section does not have an oxygen recovery pipe connected to the gas storage chamber. This approach is particularly suitable for applications with high thrust, i.e., high pump output.

[0020] Generally speaking, the gas collecting pipe section located below the water surface occupies a larger portion or has a larger volume than the gas collecting pipe section located above the water surface.

[0021] In the preferred oxygen-lift aeration system described above, oxygen bubbles generated by the aeration head drive the water upward and simultaneously dissolve oxygen in the water. The water flows to the top gas collection section of the aeration water-pushing pipe and then turns to flow horizontally. The oxygen bubbles float up and burst, releasing oxygen. The released oxygen flows back to the gas storage chamber through a recovery pipe connected to the gas storage chamber at the gas collection section, and is then re-injected into the aeration head by the air pump. After aeration and oxygenation, the water flows downward (or diagonally downward) back to the pond and continues to flow along the pond bottom, allowing the aerated, highly dissolved oxygenated water and the original pond bottom water to fully mix and flush the pond bottom, increasing the dissolved oxygen content in the lower water layer and providing targeted oxygen supply to the probiotics at the bottom of the pond.

[0022] As a preferred embodiment, in the oxygen gas lift type oxygenation system of the present invention,

[0023] The cross-sectional area of the horizontal direction of the aeration water pushing pipe (gas collecting pipe section) is larger than that of the upward (air and water inlet pipe section) and downward (water outlet pipe section) parts to facilitate the bursting and release of oxygen bubbles.

[0024] In the oxygen lift aeration system of the present invention, the gas collection pipe section of the aeration and water-pushing pipeline is typically positioned approximately parallel to the water surface, and the gas collection pipe section may only constitute a small portion of the entire aeration and water-pushing pipeline. The inlet and outlet sections of the aeration and water-pushing pipeline are typically tilted at a greater angle than the outlet sections, meaning they are closer to perpendicular to the water surface, thereby facilitating oxygen absorption by the water.

[0025] The oxygen lift aeration system of this invention recycles oxygen accumulated at the top of the pipe through a recovery pipe and resupplies it to the air pump for recycling. Theoretically, this system can achieve a near-100% oxygen utilization rate. The entire system is only open during the aeration phase, when the space between the aeration head and the oxygen recovery pipe is open. Oxygen is trapped by water at the top of the aeration water-pushing pipe, allowing for theoretical utilization rates close to 100% (even at a slow oxygen supply rate).

[0026] Preferably, in the oxygen lift oxygen enrichment system of the present invention, the volume of at least one gas storage chamber is variable, for example, the gas storage chamber or a portion thereof is a gas bag. If the volume of the gas storage chamber is variable or elastically variable, the pressure in the gas storage chamber should be maintained at a constant pressure, with only minor fluctuations. Excessive pressure fluctuations can have adverse effects: when the gas storage chamber is under a high positive pressure, the pressure increases the resistance to the upward flow, reducing the flow rate; and when the gas storage chamber is under a high negative pressure, the horizontal water flow can fill the pipe, further blocking the oxygen recovery pipe and affecting oxygen recovery efficiency.

[0027] In the gas-lift oxygen enrichment system of the present invention, at least a portion of at least one gas storage chamber can be made of a non-elastic material or an elastic material. By employing a variable-volume gas storage chamber, for example, at least one gas storage chamber being a conventional airbag or a rubber airbag, the gas pressure can be adjusted by utilizing the volumetric variation of the gas storage chamber. When the gas storage volume increases, the airbag is inflated, and when the gas storage volume decreases, air is withdrawn from the airbag, thereby preventing noticeable pressure fluctuations.

[0028] In the oxygen gas lift type oxygen enrichment system of the present invention, if a volume-variable gas storage chamber is not used, the normal operation of the system can also be ensured by the following auxiliary adjustment methods:

[0029] a. Increase the horizontal height of the aeration water pushing pipe, but its disadvantage is that for the aeration head of the same depth, the aeration stroke becomes shorter;

[0030] b. Install a flow sensor at the outlet of the aeration water pipe. If the flow is too small, it means the air pressure is too high. Stop the air supply for a period of time or reduce the air supply.

[0031] c. Install a water level sensor at the initial stage of the aeration water pipe (outlet pipe section). If the water level is too low, it means the air pressure is too high. Stop the air supply for a period of time or reduce the air supply;

[0032] d. Install a water level sensor in the oxygen recovery pipe. If the water level is too high, it means the air pressure is too low and the air supply should be increased.

[0033] e. Install an air pressure sensor in the air storage chamber and set upper and lower limits to adjust the air supply;

[0034] f. Install an air compensation valve in the air storage chamber or at its inlet and outlet. When the air pressure exceeds the adjustment limit, open the air compensation valve to restore it to normal pressure. The air compensation valve can also be replaced by an air compensation port.

[0035] The above methods all have the problems of too small adjustment range and too frequent adjustment, but they can all be used as auxiliary methods of the present invention.

[0036] In the oxygen gas-lift aeration system of the present invention, the variable volume gas storage chamber used can also be made of a thinner, inelastic material, with almost no pressure change within the upper and lower limits of the volume. In addition, the frequency of the auxiliary adjustment mentioned above is still very low. For example, a cubic gas storage chamber with a side length of 1 meter has a variable volume of 800 liters; the oxygen consumption is 20 liters per minute, and the gas supply error is 5%, that is, 1 liter of oxygen is supplied more per minute, and it takes 800 minutes to exceed the gas storage chamber adjustment limit. 20 liters of oxygen per minute is 41 kilograms per day and night. If all of it is dissolved in water, it can increase the dissolved oxygen content of 10 acres of water surface and 2 meters deep by 3 mg per liter.

[0037] In addition, in addition to the auxiliary adjustment method mentioned above, in the oxygen gas lift type oxygen enrichment system of the present invention, a limit switch can also be used for adjustment, and adjustment can be made when the air pressure has not changed.

[0038] In the oxygen lift aeration system of the present invention, the oxygen delivery pipe may be further provided with a return pipe and a flow control valve located within the return pipe. The return pipe and flow control valve are provided so that when the air pump supply significantly exceeds the aeration head consumption, the flow control valve can be opened to allow some compressed oxygen to flow back, thereby preventing damage to the air pump caused by excessive pressure buildup.

[0039] In the oxygen lift aeration system of the present invention, the air storage chamber may be further provided with an air compensation valve. This air compensation valve has at least three functions: (1) when the air storage volume in the air storage chamber exceeds the upper and lower limits, the air compensation valve can be opened to ensure smooth circulation; (2) when the water body does not need to be aerated and only needs to be stirred, the air compensation valve can be opened to reduce or stop the oxygen supply to save oxygen; (3) when ammonia nitrogen in the water body volatilizes during the aeration process and flows into the air storage chamber in large quantities, the air compensation valve can be opened to ventilate the air storage chamber.

[0040] In the oxygen lift aeration system of the present invention, the water inlet of the aeration water push pipe can be set at the lower part of the water body or at the upper part of the water body. If the water inlet is set at the upper part of the water body, the upper layer of water can be taken for water push. This has the following advantages: (1) the oxygen produced by the green algae in the upper layer of water is sent to the bottom of the pond, which can save a lot of oxygen; (2) the upper and lower waters are convective, which makes the stirring more effective. However, it also has disadvantages: (1) water with low dissolved oxygen content is not taken, which makes the aeration efficiency lower; (2) it is easy to cause the bottom water temperature to change suddenly, causing stress to fish and shrimp.

[0041] Preferably, in the oxygen gas-lift aeration system of the present invention, the water outlet of the aeration water-pushing pipe is arranged at the lower part of the water body, or even at the bottom of the water body, such as near the bottom of a pond.

[0042] Preferably, in the oxygen gas-lift aeration system of the present invention, a booster water pump can be further provided. The booster water pump can be installed in the upward stage of the aeration water-pushing pipeline (i.e., the air and water inlet pipe section) to increase the lift, or it can be installed in the downward stage (water outlet pipe section) to help release oxygen bubbles, but both will increase costs and energy consumption.

[0043] Preferably, in the oxygen gas lift aeration system of the present invention, the air pump uses a pressure of about 30-40KPa as much as possible. Too high a pressure will waste electricity, and too low a pressure will not be able to press oxygen into deeper water. Even if it can, the aeration volume will be reduced. It is best to use a frequency converter for adjustment.

[0044] In the oxygen gas lift aeration system of the present invention, since the aeration head blocks part of the flow area, the cross-sectional area of the aeration water pushing pipe where the aeration head is placed should be enlarged to ensure the flow area of the water.

[0045] Compared to existing technologies, the advantages of the oxygen gas lift aeration system of the present invention are: 1. Oxygen aeration is far more efficient than conventional aeration. 2. Because oxygen can be recycled, there's no need to use excessively small aeration holes, which reduces aeration pressure and energy consumption. Clogged aeration holes are also less likely. 3. The gas lift method achieves extremely low water lift, fully embodying the principle of low lift and high flow, further reducing energy consumption. 4. The system eliminates the need for violent agitation of the water surface, reducing the loss of oxygen from the supersaturated upper layer of water produced by algae oxygenation. 5. It can achieve higher dissolved oxygen levels, significantly improving the growth and reproduction of fish and shrimp, as well as beneficial bacteria in the water. Research has shown that fish and shrimp in high dissolved oxygen environments eat more, excrete less, and grow faster. 6. It can provide emergency treatment for severely hypoxic water bodies, rapidly restoring dissolved oxygen levels. 7. During factory aquaculture feeding, it can pre-increase dissolved oxygen levels to a supersaturated state to offset the sudden drop in dissolved oxygen levels after feeding.

[0046] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. However, these specific embodiments are merely illustrative of certain specific embodiments of the present invention and are not intended to limit the present invention. Any changes or modifications based on the present invention remain within the scope of protection of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 is a schematic diagram of a first embodiment of the oxygen gas lift type oxygen enrichment system of the present invention;

[0048] Figure 2 is a schematic diagram of a second embodiment of the oxygen gas lift type oxygen enrichment system of the present invention;

[0049] Figure 3 is a schematic diagram of a third embodiment of the oxygen gas lift type oxygen enrichment system of the present invention;

[0050] Figure 4 is a schematic diagram of a fourth embodiment of the oxygen gas lift oxygen enrichment system of the present invention;

[0051] In the figures, the reference numerals are:

[0052] 1 air pump

[0053] 2 Gas pipeline

[0054] 3. Oxygen source

[0055] 4 aeration heads

[0056] 5Aeration water push pipe

[0057] 51 air and water intake pipe section

[0058] 52 gas collecting pipe section

[0059] 53 outlet pipe section

[0060] 54 water inlet

[0061] 55 water outlet

[0062] 6 Gas storage chamber

[0063] 7Oxygen recovery pipe

[0064] 8 Reflux pipe

[0065] 9Flow control valve

[0066] 10 Air compensation valve

[0067] 11 Booster water pump. DETAILED DESCRIPTION

[0068] Example 1

[0069] like Figure 1 As shown, it is a specific embodiment of the oxygen gas-lift oxygenation system for aquaculture water bodies of the present invention, which includes an air pump 1 for circulating oxygen, an air pipe 2 for transporting oxygen, an oxygen source 3 for providing oxygen, at least one aeration head 4 for forcibly transferring gaseous oxygen in the oxygen to liquid water in the water body, at least one aeration water-pushing pipe 5 supported by a float, and at least one air storage chamber 6; wherein, the air pipe 2 transports oxygen to the aeration water-pushing pipe 5 through the aeration head 4.

[0070] The aeration water pushing pipe 5 further includes an upward air and water inlet pipe section 51, an air collecting pipe section 52 parallel to the water surface, and a downward water outlet pipe section 53; wherein, the air and water inlet pipe section 51 and the water outlet pipe section 53 are both located below the water surface, and the air collecting pipe section 52 connects the air and water inlet pipe section 51 and the water outlet pipe section 53, and is located above the air and water inlet pipe section 51 and the water outlet pipe section 53.

[0071] The aeration head 4 is arranged in the air and water inlet pipe section 51 , and aerates the oxygen pumped by the air pump 1 in the air and water inlet pipe section 51 .

[0072] Part of the gas collecting pipe section 52 is located below the water surface and part of it is located above the water surface. An oxygen recovery pipe 7 is provided between the gas collecting pipe section 52 and the gas storage chamber 6 to transport the oxygen collected by the gas collecting pipe section 52 to the gas storage chamber 6 to improve the utilization rate of oxygen.

[0073] The air storage chamber 6 is located above the water surface, is connected to the oxygen source 3, and is connected to the gas collecting pipe section 52 via the oxygen recovery pipe 7. The main body of the air storage chamber 6 is a rubber air bag.

[0074] The oxygen delivery pipe 2 may be further provided with a return pipe 8 and a flow control valve 9 located therein. When the air supply of the air pump 1 is much greater than the air consumption of the aeration head 4, the flow control valve 9 may be opened to allow some of the compressed oxygen to flow back, thus preventing the air pump 1 from being damaged by excessive pressure.

[0075] Example 2

[0076] like Figure 2 As shown, it is another specific embodiment of the oxygen gas lift aeration system for aquaculture water bodies of the present invention. The other structures of this embodiment are the same as those of Example 1, except that an air compensation valve 10 is provided on the air storage chamber 6, and a booster water pump 11 is added to the aeration water pushing pipe 5.

[0077] Example 3

[0078] like Figure 3As shown, it is another specific embodiment of the oxygen gas lift aeration system for aquaculture water bodies of the present invention. The other structures of this embodiment are the same as those of Example 1, except that an oxygen recovery pipe 7 is added to the water outlet pipe section 53.

[0079] Example 4

[0080] like Figure 4 As shown, it is another specific embodiment of the oxygen gas lift aeration system for aquaculture water bodies of the present invention. The other structures of this embodiment are the same as those of Example 2, except that the water inlet is arranged at the upper part of the water body.

Claims

1. An oxygen gas-lift aeration system for aquaculture water, the oxygen gas-lift aeration system comprising an air pump for circulating oxygen, an air pipe for transporting oxygen, an oxygen source for providing oxygen, at least one aeration head for forcibly transferring gaseous oxygen from the oxygen to liquid water in the water body, and at least one aeration and water-pushing pipe supported by a float; the air pipe transports oxygen to the aeration and water-pushing pipe through the aeration head; It is characterized by: The oxygen gas lift type oxygen enrichment system further comprises at least one gas storage chamber; The aeration water pushing pipeline further includes an air inlet and water inlet pipe section, an air collecting pipe section and a water outlet pipe section; wherein the air inlet and water inlet pipe section and the water outlet pipe section are both located below the water surface, and the air collecting pipe section connects the air inlet and water inlet pipe section and the water outlet pipe section and is located above the air inlet and water inlet pipe section and the water outlet pipe section; The aeration head is arranged in the air and water inlet pipe section, and aerates the air and water inlet pipe section with the oxygen pumped by the air pump; The at least one gas storage chamber is at least partially located above the water surface, is connected to the oxygen source, and is connected to the gas collecting pipe section and / or the water outlet pipe section; The oxygen gas-lift oxygen enrichment system further comprises at least one oxygen recovery pipe connecting the at least one gas storage chamber with the gas collecting pipe section and / or the water outlet pipe section to transport the collected oxygen to the at least one gas storage chamber; the volume of the at least one gas storage chamber is variable; The water inlet of the aeration water pushing pipe is arranged at the lower part of the water body or the upper part of the water body; the water outlet of the aeration water pushing pipe is arranged at the lower part of the water body.

2. The oxygen gas lift type oxygen enrichment system according to claim 1, characterized in that: A portion of the gas collecting pipe section is located below the water surface, and a portion is located above the water surface.

3. The oxygen gas lift type oxygen enrichment system according to claim 1, characterized in that: The at least one air storage chamber is an air bag or at least a part of the at least one air storage chamber is an air bag.

4. The oxygen gas lift type oxygen enrichment system according to claim 1, characterized in that: The gas transmission pipe is further provided with a return pipe and a flow regulating valve located in the return pipe.

5. The oxygen gas lift type oxygen enrichment system according to claim 1, characterized in that: The at least one air storage chamber is further provided with an air compensation valve or an air compensation port.

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