Comprehensive analysis of three aerators commonly used by farmers

If the aquaculture industry wants to obtain good returns and high yields, it is certainly inseparable from the use of aquatic machinery and equipment. No matter where you go, you will see that each fish pond is more or less equipped with several aerators.

Speaking of aerators, there are various types of aerators, including impeller aerators, jet aerators, waterwheel aerators, and recently popular variable frequency aerators. The working principles and characteristics of each machine are different, so how should we choose according to our own breeding species, breeding density, and pond area?

Working scene of frequency conversion aerator

Whenever I encounter such a problem, I am very tangled and do not know how to answer. In fact, regarding the configuration of aerators, what aerators have been used has been a controversial topic. We mainly configure based on experience, preferring more to less.

What kind of aerator to choose depends on what pond is used and where.
1. Oxygenation in the feeding area, we can choose waterwheel, rocket, jet

2. For fry ponds, you can use jet or pump aerators

3. Crab and crayfish ponds can use bottom aeration to increase oxygen; for Penaeus vannamei, waterwheel, surge, bottom explosion, impeller are all optional.

1. Impeller aerator

The function of the impeller aerator is mainly in three aspects: one is aeration, the other is aeration, and the harmful gases such as H2S and CO2 accumulated in the water are discharged in time to reduce the harm to the breeds; the third is to stir the water body to make The upper and lower water layers convection to achieve the purpose of balancing water temperature and dissolved oxygen.

All aerators produced by aerator manufacturers must be brought to the National Fishing Equipment Testing Center to test their aeration efficiency or aeration capacity. "National Fishery Machinery Testing Center-Test Report"! The national standard of 1kw/220V oxygenation capacity requires ≥1.6kg/h, and the fish frequency conversion test result is 1.99kg/h; 1.5kw/380V, the oxygenation capacity national standard requires ≥2.3kg/h, and the fish frequency conversion test result is 2.61 kg/h!

2. Waterwheel aerator

Waterwheel aerator is the widely used aerator in Japan, Southeast Asia and Taiwan in aquaculture. It is mainly composed of 6 parts: motor, reducer, coupling, impeller, frame and floating boat. After more than 30 years of continuous improvement, the impellers and floating boats are all fully plastic. The reducer whose drive shaft is turned into stainless steel also has the original worm gear into bevel gear or planetary gear. Not only the weight of the whole machine is reduced, the appearance quality is good, but the corrosion resistance and power efficiency are also greatly improved. At present, waterwheel aerators are widely used in eel and shrimp farming in coastal provinces in the south of my country. The products have been formed into series, which are divided into 0.75 kw, 1.1 kw and 1.5 kw according to the power of the supporting motor. And their corresponding aeration efficiency is: 1.75 kg/h for 0.75 kw, 2.27 kg/h for 1.1 kw, and 2.77 kg/h for 1.5 kw.

A large number of experimental studies have shown that the waterwheel type aerator has good aeration and stirring functions for aquaculture waters within 1m of water depth, and the ability to exceed 1m gradually weakens, and there is al no aeration for waters below 1.5m. Therefore, the waterwheel type aerator is suitable for aeration of aquaculture water in shallow ponds. At the same time, the waterwheel type aerator is more suitable for fish that like water flow such as eels. For example, the four diagonals installed in the fish pond allow the surface water to flow and circulate, and promote the increase of dissolved oxygen in the upper water. Of course, the direction of the water flow should be consistent. Therefore, the location of the waterwheel is not random. The principle is to make the water flow form a circular cycle; in fact, it is also a man-made flow-type breeding mode.

There are also many people who put a waterwheel upstream of the feeding area and open it during feeding to solve the problem of insufficient dissolved oxygen during feeding, which is a mode of so-called aeration in the feeding area. It is not difficult to find that the waterwheel is basically placed in the place where the water level of the entire fish pond is shallow, so the waterwheel type aerator is affecting the surface water or the upper and middle water, but it cannot be denied that its aeration capacity is 1.5kw. The waterwheel is even more efficient than the 1.5kw impeller type aeration. It is also meaningful to match the waterwheel type aerator in the fish pond.

Finally, a summary: 1. The waterwheel type aerator has a significant effect of aeration on the surface or middle and upper layers; 2. It is suitable for aeration in the feeding area; 3. One is placed in each of the four corners to circulate the water flow.

3. Microporous aerator

The working principle of the microporous aerator is to pressurize the air through a three-bladed Roots blower or a vortex blower to drive the air to the bottom of the fish pond, which can accelerate the diffusion of the toxic gas generated in the bottom layer under hypoxic conditions into the air, so that The aeration tube expands evenly and reaches the design value. A large number of fine bubbles (diameter: 20-30μm) emerge from the tube wall, and are in a state of smoke dispersion in the water. The rising speed is extremely slow and the dissolved oxygen effect is significant, thereby greatly increasing the water content. The oxygen content changes the dissolved oxygen content of the breeding water from bottom to top, increases the fluidity of the water, and increases the breeding density.