We know that. In aquaculture, dissolved oxygen in water is a very important index. It's not just fish and shrimp that need a lot of oxygen to grow. And many organic compounds, such as bait, fish faeces, and algae in water, require large amounts of oxygen during the process of death or decomposition. Therefore, maintaining high dissolved oxygen in water is a very important key factor for the success of aquaculture. Traditional earthen pond culture, the pool mud at the bottom is easy to accumulate. At night, fish and shrimp respiration, algae decomposition, removal of toxic substances need oxygen, so at night, the pond, dissolved oxygen is often very low. If the alert value is exceeded, it is not safe for aquaculture species.
Dissolved oxygen mode and sources of oxygen consumption in traditional aquaculture:
Changes of dissolved oxygen in pond:
There have been many such cases of dead fish:
And high-density circulating aquaculture, because the aquaculture density is higher, so dissolved oxygen is not low. Not only do fish and shrimp need enough dissolved oxygen to breathe, but also the decomposition of ammonia nitrogen, nitrite, hydrogen sulfide and so on in water needs a lot of oxygen. Therefore, it is very important to develop an efficient oxygen dissolving device.
The traditional way of dissolving oxygen
So how do you add dissolved oxygen to a body of water? In traditional aquaculture, most people add oxygen to the water through fans, nano aerators, aerosols, etc. The bubbles produced by this type of oxygenation have large diameters. As a result of buoyancy, air bubbles stay in the water for a very short time. By oxygen bomb release pure oxygen, pure oxygen by ceramic aeration in the water to bubble, the bubble diameter of only about 0.5 mm, the time duration of the air bubble in water is only about two seconds, in these two seconds short period of time, ruled out due to too much bubble diameter and the small contact area of water, oxygen and water contact time is too short, the proportion of oxygen dissolved in water is very low, most of the oxygen by bubble overflow water is wasted.
Conventional oxygenation involves pumping gases (air or oxygen) into water to form bubbles, allowing the gas to come into contact with the water, and through gas-liquid contact, dissolving the oxygen into the water. More typical is roots fan, roots fan used in aquaculture has a lot of hard injury.
1. Power consumption is relatively large, roots fan power is often several kilowatts of power. For large water bodies, the power consumption of roots fan is staggering.
2. Roots fan's air source comes from air. In the summer, when it is hot, the outdoor temperature may reach more than 30 degrees or even close to 40 degrees, and the air will be even hotter after compressed by roots fans. As the water continues to flow, the temperature of the water will increase. We know that the dissolved oxygen in water is the higher the temperature, the lower the dissolved oxygen. After the use of roots fan, not only can not play a very good effect of oxygen, but also because of the high water temperature may lead to decreased dissolved oxygen. If it is winter, the cold air will further reduce the temperature of the aquaculture water body, which will greatly affect the heating cost.
3. Roots fan USES air to add oxygen to water, because the oxygen content in the air itself is not high, so the overall efficiency is not high
4. Roots fan combines with nano aerator and other accessories to add oxygen to the breeding water. Due to low efficiency, a large amount of gas is needed to enter the water. And the continuous flow of water may cause excessive passive movement of fish and shrimp. It affects the growth rate of fish and shrimp.
The roots fan is noisy. It may cause trouble to the farmed fish and shrimp. It affects growth.
Under the condition of recirculating aquaculture, if the aquaculture density is higher than 30 kg per cubic meter, it is necessary to add oxygen to the aquaculture water with pure oxygen. At present, the best nano ceramic aeration sheet, the bubble diameter produced in water is not less than 0.5mm. A lot of pure oxygen is wasted. So how do we prevent pure oxygen from being wasted? After a lot of thinking, analysis and testing, lanling aquatic product technology has launched this pure oxygen dissolved oxygen device.
Research and development history of pure oxygen dissolving apparatus
Is our way of thinking, blue ling reverse thinking, filling the pure oxygen in a container, we let the water through the pure oxygen, through a certain method, oxygen and water inside the equipment to fully contact, high dissolved oxygen in the water flowing from the bottom of the equipment, in the process of this part of the bubble, due to the effect of buoyancy, it will return to the top of the equipment, the entire device is sealed. So the water that goes through the device consumes as much pure oxygen as it can dissolve. And when you do that, you get a very high utilization of pure oxygen.
In 2018, guangzhou lanling aquatic technology co., ltd. launched the pure oxygen dissolved oxygen device for the first time, which attracted the attention of many friends in the aquatic industry. Everyone is asking when our products can be put on the market for sale, but lanling aquatic technology takes a very rigorous attitude, before the products are found, analyzed, optimized and eliminated after a long period of operation. We haven't launched this product yet.
After the first version of pure oxygen dissolved oxygen apparatus was introduced we found that. There are some accessories on this equipment, and the safety needs to be improved. In the case of long-term operation, faults may occur, which may cause immeasurable losses to aquaculture customers. Therefore, we conducted the second round of product test and optimization. During the second round of product test and optimization, we found that the power consumption of the whole device was a little high. Some very experienced aquaculture customers have given us valuable advice. So we did a third round of testing. In the energy consumption of the whole equipment.
Third round of test
After four rounds of testing and optimization, we have basically determined two specifications of this pure oxygen dissolved oxygen device, one for the treatment of 200 square meters of water, and the other for about 500 square meters of water, which is quite appropriate. In the process of testing, we have obtained a lot of primary data. At present, for 70 cubic water bodies, the cultivation density is 46 kg per cubic, and PO700 pure oxygen dissolved oxygen device is used to increase oxygen in water bodies, which can keep dissolved oxygen above 7PPM. The utilization rate of pure oxygen can reach 80%. Specific to configure which specification of pure oxygen dissolved oxygen device, need to be based on the total amount of circulating water, breeding density, breeding methods to carry out scientific calculations. Specific product parameters can be referred to the link
High dissolved oxygen retention
Treated water retains a higher dissolved oxygen content after a period of time. This means that by increasing oxygen in this way, oxygen and water can form a stable chelating state without escaping from the water after a period of time. The following figure
When pure oxygen dissolves into water, some ammonia nitrogen and carbon dioxide are released from the water. So this equipment actually has a certain effect on the removal of ammonia nitrogen and carbon dioxide in water. The precipitation of carbon dioxide from the water will lead to certain changes in the ph and hardness of the aquaculture water. The lower the solubility of carbon dioxide in water, the better for aquatic animals. At the same time, it can prevent the acidification of water after long-term operation of high-density circulating aquaculture. After the pure oxygen dissolved oxygen device runs for a period of time, a large amount of carbon dioxide, ammonia, water vapor and other gases will accumulate inside the equipment. We can get rid of these gases regularly by manual setting.
Removal of nitrite
We know that nitrites in water are toxic to fish and shrimp. And the problem of nitrite in aquatic industry is a long-standing problem that has been troubling farmers. Highly dissolved oxygen water can oxidize nitrite in the water to form nitrates that are non-toxic to fish and shrimp. And basically solve a lot of nitrite poisoning. A series of disease problems such as low resistance of fish and shrimp.
Why not use it with oxygen generator?
It is important to note that this pure oxygen dissolving device works with liquid oxygen cylinders (dewar bottles). It is not used with oxygen generator at present. The main reasons are as follows:
1. On the one hand, since liquid oxygen will have certain pressure after gasification, it can save a lot of power consumption in the intake and other links.
2. The long-term running cost of liquid oxygen is lower than that of oxygen generator. At 0.6 yuan per kilowatt hour, the average cost of producing one kilogram of pure oxygen is about 1.2 yuan. The average cost of liquid oxygen is about 1.0 yuan per kilogram. Obviously, using liquid oxygen cylinders as a source of oxygen costs less.
3. In aquaculture, we generally do not recommend the product of oxygen generator unless there are special circumstances. Because its supporting accessories are too many, especially molecular sieve and high-pressure air pump accessories, heat, the failure rate is relatively high.
4. The use of liquid oxygen cylinder also has an advantage, is it stored in the liquid oxygen will produce a greater pressure after volatilization. In the case of power failure, thunderstorm and other light and extreme weather, we can connect the nano-ceramic aerator plate and other accessories with oxygen cylinders for use. Oxygenate the aquatics tank. It can solve some emergencies very well.
Pure oxygen dissolved oxygen apparatus is mainly used in circulating aquaculture. The purpose of high dissolved oxygen can be achieved by using some water head pressure of the main circulating pump of the system to separate the flow rate of a bypass. After returning to the system, the highly dissolved oxygen water should be mixed and diluted with the effluent from the main circulation channel as soon as possible. So that the dissolved oxygen effect can be better maintained. The following figure
Outside the pond using
The water quality of waitang is easily affected by external water source, light and other factors, and the dissolved oxygen fluctuates greatly. And generally the amount of water outside the pond is not small, so the use of pure oxygen dissolved oxygen device to increase oxygen, the effect will be the outer pond itself algae, fungi and other organisms caused by the dissolved oxygen fluctuations "submerged", so the use of pure oxygen dissolved oxygen device the final effect is not obvious. At the same time, only the breeding density is very large (unit area economic benefit is higher), it is necessary to use pure oxygen dissolved oxygen device. Therefore, we suggest that if we want to use pure oxygen dissolved in the pond, either the breeding density is high, or the dissolved oxygen in the pond water is too low at night. Then open the pure oxygen dissolving apparatus at night, which can better avoid the situation of too low dissolved oxygen in outdoor pond water at night.
Customer feedback and financial accounts
A lot of people will say the price of the equipment is too high. Let's take the practical use of a customer as an example. Two bottles of liquid oxygen if he is now a day, according to five days after the use of pure oxygen dissolved oxygen device using a bottle of computing (according to the largest breeding density, the lowest utilization), a standard dewar bottle of liquid oxygen to about $350, which is a day of oxygen consumption decreased to 70 yuan from 700 yuan a day every day, a month can save the cost of 18900 yuan of oxygen. Save more than 220,000 yuan a year.
Smart you, still think the equipment is expensive?
Finally, enjoy video from the last test:
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Contact: Jack Lee
Add: Guangdong guangzhou