What do you need know before you Select Disc Diffuser?
Written by： jasmine
Contact name: Kate@aquasust.com
1. The size of the Disc Diffuser
Best selling: DD260, 9-inch model, followed by DD 215, 8-inch. Customized orange.
When choosing the size of the aeration pan, first understand the client's budget. The larger the aeration pan, the wider the service area, the more expensive the price, the greater the impact of various gas volumes, and the shorter the service life. The smaller the aeration pan, the smaller the service area and the cheaper the price. The same quality is small, and the service life of the small aeration pan is longer. But the total cost calculation is relative.
For example, in a sufficiently large aeration tank, the overall cost of a small aeration pan will be greater than that of a large aeration pan.
2. Relevant material and quality of aeration disc membrane skin
At present, there are three main materials on the market, EPDM/silicone/foam.
More than 80% of the projects use EDPM membranes, and only a small number of special water quality use silicone membrane aeration discs, such as pharmaceutical factories, etc. The reason is that the silicone material has better corrosion resistance, heat resistance, weather resistance and water resistance. Customers with sufficient budget can also choose a membrane made of silicone.
EDPM film skin is divided into extruded skin and molded skin. With the same production formula, the performance of extruded film skin is 30% worse than that of film pressure film skin. The advantage of the film laminate is that the film laminate is similar to the injection molded part, and its size is exactly the same, and the extruded film will be large or small. The disadvantage is that the production speed is slow, which is about 30% more expensive than the extruded film cost, and about 5% more expensive if the entire project budget is included.
The quality of the film is also related to the formulation of the product. The film with a glue content of more than 50% has better quality and better elasticity.
3. The material of the aeration pan plastic
At present, the materials such as aeration pipes are divided into three categories, ABS/PVC/PP, ABS is currently the most convenient in actual use, and is usually connected with connectors such as glue and hoop. The connecting parts are divided into three types: 3/4 saddle head and hoop, base and cable tie. Among them, the hoop is the most reliable and the most expensive. Affected by the price fluctuation of plastic raw materials, the price of each material is also changing, and the cost of ABS and PVC was lower before.
Fourth, the weight of the aeration plate
Ordinary aeration pan 300mm 0.7KG
260mm 0.55KG
215mm 0.3KG
Flat plate aeration pan 300mm 0.8KG
260mm 0.5KG
215mm 0.35KG
5. The ventilation volume of the aeration plate
The standard ventilation volume of 270MM is 2CBM, and the standard ventilation volume of 215MM is 1.5CBM.
6. The service area of the aeration pan
The service area of the aeration pan is usually a range of values, such as 3-5M3. How can we recommend to customers who are uncertain about their usage?
The smaller the service area of the aeration pan, the better, and even 120% of the volume should be distributed to customers. Avoid damage during installation and later replacement.
Considering that the water in the aeration pan flows upwards to both sides, more and denser aeration pans should be arranged on the edge of the sewage pool than in the pool, so as to avoid the accumulation of fillers and debris in the water that cannot flow on the edge of the sewage pool.
Seven, the use of water depth of aeration pan
Six meters, usually the sewage pool is about six meters, and the water depth below six meters can operate normally. The deeper the water, the greater the pressure on the aeration pan, and the effect of the aeration pan may be affected.
8. Three aspects that affect the life of the aeration disc
1. The quality of the plastic parts of the disc and the quality of the film
2. During the operation of the project, it is best to run it continuously. Turning the switch on and off will cause damage to the aeration plate.
3. Whether the installation of the aeration pan is flush with the ground, level and balanced.
9. Where is the quality difference between the aeration discs?
1. The fineness and uniformity of the aeration holes on the membrane skin, and whether the air can be discharged evenly and finely.
2. A good plate is thicker, has more ribs, and can bear more force.
3. The disk surface is not structured and stable during the use of the disk
10. After-sale service and product advantages of aeration trays
The warranty period is one year, and it can be replaced within one year.
Aquasust's advantages:
1. Specially exported, different from other Chinese market suppliers.
2. We have 15 production lines and the quality meets FDA standards.
3. We can provide design and custom drawings and cost estimates.
4. Our membranes come from LANXESS, Germany, and are produced using special modern vacuum molds. This is the first factory in China to use this process, and only a few factories in the United States use this process. High-quality film skin, the glue content exceeds 50%
5. Special strengthening formula, less plasticizer, ABS material adding anti-ultraviolet agent, stronger anti-ultraviolet ability.
6. Equipped with a multi-function check valve, which can be self-cleaning and prevent the backflow of sewage.
7. Color: Orange is not easy to fade.
8. Longer service life, up to 5-7 years.
11. Differences and advantages and disadvantages of aeration pan and aeration tube
Advantages of aeration pans:
A) Small maintenance requirements
B) long life.
C) Lower failure rate:
Because disc diffusers usually have smaller holes than tube diffusers, they have a lower failure rate. If an orifice develops a crack, it will leak air slower than a larger orifice and cause less damage to the overall system
D) Higher oxygen transfer efficiency: Because disc diffusers typically generate smaller bubbles, they provide a larger bubble surface area for oxygen transfer.
Disadvantages of aeration pan:
A) Requires larger sump area: The aeration pan array is not as compact as the aeration tube array, so it is difficult to fit many aeration pans into a small pool.
B) Higher cost: Disc diffuser layouts tend to cost more than aeration tube layouts, especially in configurations that require expensive stainless steel.
C) Has higher buoyancy: Flat disc diffusers have higher buoyancy than tubular diffusers.
D) Requires more labor time: Disc diffuser systems require more stainless steel than tube diffuser systems. In configurations requiring stainless steel, aeration pans sometimes require longer installation times.
E) Provides less mixing capacity: Because disc diffusers tend to produce smaller air bubbles, they provide less mixing capacity.
Advantages of aeration pipe:
1. The overall cost of the project is lower, suitable for narrow pools
2. Increased mixing capacity: Many tubular diffusers tend to produce relatively large air bubbles. The large air bubbles typically created by tubular diffusers provide superior mixing capabilities.
3. Advantages of aeration pipe, easy installation, less sediment deposition, large aeration area, and low comprehensive cost.
Disadvantages of aeration pipe:
A single aeration tube is more expensive and fewer people use it now
The same advantage lies in the extremely high oxygen transfer efficiency and energy saving efficiency
12. Calculation method of installation spacing of aeration pans
The installation distance of the aeration pan
To know the installation spacing of the microporous aeration pan, you must first know the service area of each model of the microporous aeration pan. First of all, there are two types of conventional micro-porous aeration pans. The two types of aeration pans, φ215mm and φ260mm, have corresponding service areas of 0.25-0.55㎡ and 0.35-0.75㎡ respectively. In layman's terms, there are 3 aeration heads with a diameter of 215mm per square meter, and 2.5 aeration heads with a diameter of 260mm. This arrangement can better play the role of aeration. All indicators can achieve a better balance.
Therefore, based on such experience, it can be roughly calculated that the installation spacing of φ215mm microporous aeration disks is between 500-550mm, and the installation spacing of φ260mm microporous aeration disks is between 550-650mm.
13. Reasons for small bubbles or uneven aeration in tubular aerators and aeration discs
During normal operation, the dissolved oxygen in the water is kept in an ideal state by adjusting the air flow, but the adjusted air flow should be within the allowable range of the aerator. When the air flow is high, the head loss of the aerator is large. The oxygen transfer rate is small, and the small air flow cannot fully utilize the performance of the aerator, and the aeration in the pool may be uneven, so the most ideal adjustment is within the recommended air flow range. Therefore, the reasons for the small air volume of the aerator are as follows:
1. If the air volume is insufficient, check whether the blower is running normally and whether the flow rate of the fan matches the aerator. Whether the valve on the pipeline is fully open.
2. When the aerator pipeline is installed, whether the sundries in the air pipeline are cleaned, whether the air pipeline is on the horizontal line, and the pipeline error should not be too large.
14. Reasons for violent aeration or large bubbles in aeration
1. Leakage of air distribution pipe:
Treatment method: Drain the water in the problem area, check with a small amount of air blast, determine the location of the leak and repair it.
2. The aerator is damaged:
Treatment method: Drain the water in the problem area, check the aerator with a small air volume blast, determine the leaking aerator, and replace the entire aerator.
15. Application Scope of Aeration Disc
1. Urban sewer sewage treatment system
2. Various types of industrial sewage treatment
3. Clean water treatment
4. Diffusion of ozone in various types of wastewater
5. Stabilize sludge
6. Aeration of fish ponds
7. Aeration of rivers and lakes
16. Installation steps of aeration plate
Installation and commissioning steps of aeration pan
The microporous aeration plate is a typical type of microbubble air diffusion device, which consists of a support frame, a one-way valve, a one-way valve sealing ring, and a sealing cable cover. O-ring, threaded interface, saddle frame and other parts. The diameter of the generated bubbles is less than 2mm, and the oxygen utilization rate is high. It is often installed in an assembled form and is widely used in biochemical oxidation tanks and air flotation tanks in wastewater treatment processes.
The aeration membrane of the microporous aeration disc adopts imported EPDM or silica gel aeration membrane. The O-ring at the connection between the aeration head and the thread is made of EPDM rubber and fluorine rubber.
In order to prevent other operations such as electric welding sparks and construction, concrete and other heavy objects from damaging the aeration device, the micro-porous aeration plate must be installed after the civil construction is completed before the water is discharged. The microporous aeration pan needs to be done in strict accordance with the following installation process.
1. The installation of the microporous aerator should be deployed in accordance with the requirements of the system plan and installation drawing.
2. The distance between the bottom of the gas distribution branch pipe and the bottom of the pool is about 180-200MM (or as required by the drawings), and the allowable plane height deviation is ±10MM.
3. The surface of the microporous aerator is about 230-250MM from the bottom of the pool (or as required by the drawing), and the plane deviation between the chassis and the bottom of the pipe after the installation of the microporous aerator does not exceed 5MM.
4. Before installing the microporous aeration plate, the inside of the air main pipe and branch pipe should be purged clean.
5. The firm bracket of the air branch pipe of the microporous aeration plate should be adjustable. After adjustment, the maximum deviation of the surface elevation of the microporous aerator in the unified aeration tank should not be greater than 5MM, and the maximum deviation of the surface elevation of the microporous aerator between the two aeration tanks should not be more than 10MM or as planned.
6. The firm bracket of the air branch pipe of the microporous aeration plate should have sufficient anchoring force. Anchoring with the bottom of the pool should be designed for buoyancy.
7. Each aeration unit is equipped with an independent sewage pipeline, which extends out of the water surface and is equipped with a valve.
17. Problems that should be paid attention to in the construction of aeration pan
The support frame, one-way valve, sealing cable tight cover, threaded interface and saddle frame of the microporous aeration pan are made of engineering ABS material. The following issues should also be paid attention to during construction.
1. The special adhesive pipe fittings provided by the supplier or purchased according to the supplier's requirements must be used for bonding.
2. The bonding surface should be kept clean, and it is strictly prohibited to bond under the conditions of rain or humidity.
3. Do not use dirty brushes or brushes with different materials for bonding operation.
4. Do not wipe the joints of pipes and fittings with dirty or oily cotton yarn.
5. Do not operate near the fire source or where there is an open flame.
6. During the construction process, attention should be paid to the cleanliness of the inside of the pipeline to avoid the entry of debris.
7. Water is strictly prohibited within 24 hours after the pipeline is bonded. When the air humidity is high, the time should be extended.
In order to prevent air leakage from the pipeline and the connecting part, it is necessary to debug the microporous aeration plate, mainly to test the leakage of water exceeding the bottom depth of about 10cm of the aerator. transport. The detailed steps are as follows:
1. Put clean water in the pool, the water surface to the surface of the microporous aerator is about 100-200mm, and the blower is ventilated.
2. When the water is released to engulf most of the microporous aerator, check whether the height of the microporous aerator is on a flat surface, and adjust the conditioner.
3. Check the tightness of all pipeline interfaces and the joints of microporous aerators, and whether there is air leakage.
4. Under the condition of the planned ventilation volume, check whether the aeration distribution is average, and the ventilation area of each microporous microporous aerator is greater than 80%.