Several problems should be noticed in the selection of aeration fan for sewage treatment:

1、根据实际情况计算参数

1. Calculate parameters according to actual conditions

在污水厂选择污水处理曝气风机，厂家产品样本提供的都是标准进气状态的性能参数，但风机实际使用时不是标准状态，风机的环境条件(如温度、大气压力、海拔等)不同时，风机的性能也会发生变化。设计选择时不能直接使用产品样本的性能参数，相反，根据实际使用状态，风机的性能要求必须转换为标准进气状态的风机。

When the sewage treatment aeration fan is selected in the sewage treatment plant, the performance parameters provided by the manufacturer's product samples are all in the standard intake state, but the actual use of the fan is not in the standard state. The performance of the fan will also change when the environmental conditions of the fan (such as temperature, atmospheric pressure, altitude, etc.) are different. The performance parameters of the product sample cannot be directly used in the design selection. On the contrary, according to the actual use status, the performance requirements of the fan must be converted to the standard intake status of the fan.

2、出口压力的影响因素分析

2. Analysis of influence factors of outlet pressure

容积鼓风机排气压力的高低并不取决于鼓风机本身，而是由气体从鼓风机排出后的装置，即所谓的“背压”来决定，污水处理曝气风机具有强制气体输送的特点。

The exhaust pressure of the volumetric blower is not determined by the blower itself, but by the device after the gas is discharged from the blower, namely the so-called "back pressure". The sewage treatment aeration fan has the characteristics of forced gas transmission.

鼓风机铭牌上显示的排气压力是风机的额定排气压力，实际上，鼓风机可以在低于额定排气压力的所有压力下工作，只要强度和排气温度允许，就可以超过额定排气压力。

The exhaust pressure shown on the nameplate of the blower is the rated exhaust pressure of the blower. In fact, the blower can work at all pressures lower than the rated exhaust pressure. As long as the strength and exhaust temperature allow, the rated exhaust pressure can be exceeded.

污水处理厂的情况是，排气系统产生的压力(背压)是管道系统的压力损失值、曝气池水深和环境大气压力的总和。由于某些原因，例如，由于曝气头或管道堵塞，管道系统的压力损失增加，背压上升，风机的压力也会相应增加。另外，由于曝气头破裂或管道泄漏等原因，管道系统的压力损失减少，背压持续降低，风机的压力也降低。

In the case of sewage treatment plants, the absolute pressure (back pressure) generated by the exhaust system is the sum of the pressure loss value of the pipeline system, the water depth of the aeration tank and the ambient atmospheric pressure. For some reasons, for example, due to the blockage of the aerator or pipe, the pressure loss of the pipe system will increase, and the back pressure will rise, and the pressure of the fan will also increase accordingly. In addition, due to the rupture of the aerator or or pipeline leakage, the pressure loss of the pipeline system is reduced, the back pressure continues to decrease, and the pressure of the fan is also reduced.

综上所述，在确定污水处理曝气风机压力时，只要风机在标准状态下能达到的压力，就等于使用状态下的大气压力、曝气池水深和管道损失之和。

To sum up, when determining the pressure of the sewage treatment aeration fan, as long as the fan can reach the pressure under the standard state, it is equal to the sum of the atmospheric pressure, the depth of the aeration tank and the pipe loss under the use state.

3、鼓风机气流因素

3. Blower airflow factor

计算污水处理的氧气需求时，结果是标准状态下所需氧气的质量流量qm(kg/min)转换为标准状态下所需空气的体积流量qv1(m3/min)，如果鼓风机的使用状态不标准(例如在高原地区使用)，空气密度、含水量也会发生变化。

When calculating the oxygen demand of sewage treatment, the result is that the mass flow qm (kg/min) of oxygen required under the standard state is converted to the volume flow qv1 (m3/min) of air required under the standard state. If the use state of the blower is not standard (for example, in the plateau area), the air density and water content will also change.

因此，需要计算能够提供相同质量流的体积流，即转换流qv2。在高原地区使用时，环境大气压力也会发生变化，压力相应提高，鼓风机的泄漏流量qvb会增加，鼓风机供应的空气容积流量会减少，氧气供应也会不足。

Therefore, it is necessary to calculate the volume flow that can provide the same mass flow, namely the conversion flow qv2. When used in plateau areas, the ambient atmospheric pressure will also change, and the pressure will increase accordingly, the leakage flow qvb of the blower will increase, the air volume flow supplied by the blower will decrease, and the oxygen supply will also be insufficient.

因此，在设计时，在使用条件发生变化时，考虑到各种因素的影响，风机供应的实际气流必须满足使用要求，并计算转换流量qv2和流出流量qvb2。

Therefore, in the design, when the service conditions change, taking into account the influence of various factors, the actual air flow supplied by the fan must meet the service requirements, and the conversion flow qv2 and outflow flow qvb2 must be calculated.

4、注意冬天和夏天的差异

4. Pay attention to the difference between winter and summer

风机选型要注意风机供应流量的变化规律。也就是说，同样的鼓风机在冬天和夏天容积流量不变，但流量取决于空气密度的质量，也就是说氧气供应量会有所不同。

Pay attention to the change rule of fan supply flow in fan selection. That is to say, the volume flow of the same blower remains unchanged in winter and summer, but the flow depends on the quality of air density, which means that the oxygen supply will be different.

在标准状态和使用状态下，鼓风机的容积流动不变，但空气密度、含水量等发生变化，冬季温度降低时，鼓风机传输到空气池的氧气供应增加，夏季温度升高时减少。例如，某污水处理厂在上述计算实例中使用鼓风机，根据环境温度的变化计算风机的实际供氧，而该年的变化规律是，在实际运行过程中，由于进水、水质、水温等参数的变化，系统需氧量也在夏季变化，冬季水温降低，曝气池的需氧量减少。这是因为冬季气温下降，空气密度提高，风机供应的干空气质量比标准状态大，氧气供应量增加。从运行的实际测量来看，每年冬天暴露池的溶解氧比夏天高1 ~ 3毫克/L。

Under the standard and service conditions, the volume flow of the blower remains unchanged, but the air density and water content change. When the temperature decreases in winter, the oxygen supply transmitted by the blower to the air pool increases, and decreases when the temperature increases in summer. For example, a sewage treatment plant uses a blower in the above calculation example to calculate the actual oxygen supply of the blower according to the change of the ambient temperature. The change rule of this year is that during the actual operation process, due to the change of the parameters such as water inlet, water quality and water temperature, the oxygen demand of the system also changes in summer, and the water temperature decreases in winter, and the oxygen demand of the aeration tank decreases. This is because the temperature drops in winter, the air density increases, the dry air quality supplied by the fan is higher than the standard state, and the oxygen supply increases. From the actual measurement of operation, the dissolved oxygen in the exposure pool is 1~3 mg/L higher in winter than in summer.

因此，在生产运行过程中，必须对这些变化及时调整设备，使风机的充氧能力适应实际运行中的氧气需求。对于污水处理曝气风机，使用变频器改变风机速度调整送风气流是经济实用的。

Therefore, in the process of production and operation, the equipment must be adjusted in time for these changes, so that the oxygenation capacity of the fan can meet the oxygen demand in actual operation. For the sewage treatment aeration fan, it is economical and practical to use the frequency converter to change the fan speed and adjust the supply air flow.

以上就是为大家介绍的有关四川水产曝气设备详细的介绍,希望对您有所帮助.如果您有什么疑问的话,欢迎联系我们.我们将以的态度,为您提供服务http://www.sddyfd.com/

The above is the detailed introduction of Sichuan aquatic aeration equipment introduced for you. I hope it can help you. If you have any questions, please contact us. We will provide services for you with our attitude http://www.sddyfd.com/