自动化泵站 | Festo HK

水处理离不开泵

污水处理厂里的泵永不停歇，循环大量的水。这需要巨大的机器——它们的能耗同样巨大。毫不奇怪，污水处理厂的能耗在市政电力成本中的占比高达･20%。其中很大一部分是由于增压，而泵站是第二大成本动因。当采用过时的技术时，尤其是当几个泵同时运行时，情况尤其如此。当出于冗余原因而不得不让其它泵处于备用状态时也是如此。

很明显必须实施节能过程，而此类需求呈显著上升趋势。根据经验，我们知道大多数系统都有巨大的节能潜力。让我们先看看传统的泵站。也可以直接跳转到･Festo･解决方案。

单向阀隐藏的后续成本

即使是现在，许多污水处理厂和水处理厂的泵站仍然通过机械单向阀以传统方式进行保护。通常，单向阀的作用是在泵停止时防止水回流。但是使用机械单向阀的解决方案有几个缺点。首先，它容易失效并且效率低下。

风险、磨损和损坏

主要的问题是，由于阀盘的存在，单向阀对泵的性能起着一种阻力的作用，因此必须首先克服这种阻力。这需要比实际情况更多的能量。更糟糕的是，单向阀会影响操作安全。当泵停止运转时，会形成由微生物产生的气泡，阻止泵自动重新启动。这意味着必须首先手动启动单向阀，这样气泡才能逸出，泵才能启动。

此外，从长远来看，关闭单向阀也会产生水锤效应，导致管道系统振动。这大大增加了管道损坏的可能性。还有一个因素会缩短整个系统的使用寿命：单向阀容易泄漏。而且，这些泄漏和回流很难被发现。一旦损坏变得明显，通常需要更换的不仅仅是单向阀；在最坏的情况下，必须更换整个泵。

Benefits of the pneumatic solution

Automated gate valves with pneumatic linear actuators from Festo offer a number of concrete benefits:

Cost savings: Operators of wastewater treatment plants achieve the same pumping capacity with considerably less energy.
System safety: Since the gate valves close tightly, no undetected leakages occur during operation.
System availability: Pneumatically actuated industrial process valves stand out as they are easy to operate and not very susceptible to failure. They also easily overcome high breakaway torques caused by deposits and caking by increasing the air pressure.
Failure safety: The automated emergency function guarantees a supply of compressed air, even in the event of a voltage drop.
Stability: Pneumatic actuators are impressive thanks to their sturdiness, long service life and overload protection when the gate valves are opened and closed.
Working conditions: The noise level is significantly reduced.

Example: Sindelfingen wastewater treatment plant

To date, Festo has successfully implemented the described solution in over 100 water treatment and more than 200 wastewater treatment plants. For example, at the Sindelfingen wastewater treatment plant. The plant treats the wastewater generated by roughly 250,000 residents in southern Germany. In the pumping station, which feeds the wastewater from the primary settlement tank for biological treatment, there are six centrifugal pumps, each with a power consumption of 90 kW and a pumping capacity of up to 500 l/s at a discharge head of 8 to 9 m. Depending on the volume of wastewater, up to five of these pumps are in operation at any one time. One pump is for redundancy purposes.

Prior to the upgrade, the check valves had to be kept open at all times, but this reduced the flow rate by up to 10%. In addition, the free flow cross section was reduced, and the piping system suffered from water hammer when the check valve closed.

Since we completely replaced the check valves and their functionality by pneumatically automating the existing knife gate valves, the same pump flow rate has been achieved with significantly less energy. The Sindelfingen wastewater treatment plant now saves almost 90,000 kWh of power per year. This corresponds to 2% of the wastewater treatment plant’s total energy requirements and represents an annual saving of over 11,000 euros. The municipal authority invested 25,000 euros in this solution. If you do the maths, you’ll see just how quickly Festo automation pays for itself.