Advantages and disadvantages of various aerator
Oct 11, 2018

Now the world, the number of disc aerator is more, but the trend of tube to replace it, and it is obvious.

Now the main use of fine bubble diffuser, from the material point of view, mainly divided into: ceramic fine bubble diffuser; or membrane fine bubble diffuser (including disc and tube) aerator, each has its advantages and disadvantages, but the film is absolutely the mainstream, corundum and ceramics in foreign countries have been used less and less. 

1. As far as oxygen transfer efficiency is concerned, good corundum and ceramic fine bubble diffuser are not inferior to or even higher than membrane fine bubble diffuser .Their principle is to pour a bunch of mixtures, quartz sand, lime and so on into the mold, and then burn them through several sections of the process, so that the mixture inside burns out, fills the pores, and when air passes through these pores, it is divided into tiny bubbles. (I didn't make this stuff. I'm not sure if it's right. Welcome to correct me). 

The biggest drawback of ceramic fine bubble diffuser is that their pores will be fouled. The pressure loss is relatively stable at the beginning of the aerator operation, but after a certain period of operation, the pressure head loss will suddenly increase sharply - this is the reason for scaling. The cause of scaling is divided into two categories.

This situation can not be avoided, even if you continue to aerate continuously, it will also grow. But according to some of the clients I met, there's something special about the quality of domestic sewage in their area that doesn't exist, but who knows? They just feel it, they don't provide data, and I can't go on asking.

After biofouling, there are two main solutions: 1. Add acid to the aeration pipe to clean, while running while adding. This control is very mature. However, after the sewage plant is stable, many systems will be added about 12 hours, as to the amount of use, depending on the specific situation.

2. Remove the aeration head and throw it into the oven. After burning, it can be regenerated, approaching a completely new state -- but rather troublesome.

According to the mainstream view, corundum and ceramic aerator can be run permanently and will not be damaged. In fact, it is not true for every brand. Because corundum or ceramic aerator production process is relatively more, from the material and process must be more strictly implemented in order to produce high-quality products. If the process or material is not properly closed, it will lead to the use of a period of time, some things in the pores fall off, pore enlargement, oxygen transfer efficiency decreased. It can be said that from the sample alone, you have to judge the quality of a corundum or ceramic aerator, is quite difficult - more difficult than the judgment of membrane microporous aerator.

    In terms of cost, ceramics are more expensive and absolutely more expensive than rubber membranes, which is why they are used less and less. Of course, this is relatively expensive, you take home-made corundum ceramics, and the imported membrane aerator, it is cheaper.

The ceramic fine bubble diffuser has no check function, generally only disk type, and I have only seen disc type.  

2. Membrane fine bubble diffuser, the structure is basically relatively simple. Inside is a support plate (or tube), and then the membrane is sleeved outside, by tightening, or stainless steel clamps, fixed, OK. There are two kinds of connection between aerator and gas pipeline, thread connection and installation connection.

The core part of membrane fine bubble diffuser is the aeration membrane itself. There are two key points: punching way and material.

There are two main ways to punch holes: laser drilling and mechanical drilling. Laser drilling is a small hole burning on the surface of the membrane by laser irradiation. The disadvantage is that the material is damaged, and the rubber around the hole is deteriorated, poor closure performance, basically not used abroad. Mechanical drilling, is the use of precision tools to cut the surface of the film, generally should be non-destructive material, so in the air, the hole opened, not aerated when the hole automatically closed to prevent leakage.

Now pick up some private goods and push your products. EDI diaphragms have been opened/closed every five seconds after a million open/close durability tests, and after a million times, they have proved to be fairly good at closure performance - as every brand of aerator now claims.

Get down to business.

Now, the most commonly used material is EPDM. This kind of rubber is considered the best choice from the aspects of durability, life, aging resistance and hydrophilicity. The rubber is the most suitable material for biological wastewater treatment, and the membrane made of this material should also be used for conventional industrial wastewater treatment.

Specific to each brand of rubber material, some formulations, is the core of aerator business. Because this directly affects the performance and life of the aerator. For example, if you want to tighten the hole a little and make it thinner, this will improve the efficiency of oxygen transmission. However, if the material fails to meet the requirement, the hole will be thinner. If you have the opportunity to contact, we might as well compare the perforation density of each manufacturer's diaphragm. Also, the general good rubber film, the surface gloss is relatively small, as shiny as leather shoes that, in fact, the sulfur content of rubber is more, easy to aging and hardening over time, pressure loss will increase.

But it also has external hazards, mainly hydrocarbon and aromatic. If there is a lot of chemicals in the sewage, it can not be tested.

More inquiries can be contacted from:

KHN water treatment equipments Co., Ltd.




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