超滤中的完整性测试

自动化测试和控制

超滤系统和膜过滤均用于水处理和工业水处理厂。保压测试是测试过滤器完整性的有效方法。必须定期进行测试，以防止滤液污染。在该测试过程中，向各个膜组件供应受控压缩空气，持续两三分钟，并测量压降。如果测量结果偏离参考值，则表明膜存在泄漏。

可以自动化实施完整性测试，其方式与保压测试本身一样可靠。这一点的关键是 Festo 的 CPX/MPA 系统，用作带集成气动元件的远程输入/输出系统。它允许使用模拟量输入卡通过直接气源口记录气管中的压力，为您提供精确的泄漏测试。

CPX/MPA･直接安装在现场，可以使用通用现场总线协议轻松连接到中央控制器。此外，这几乎不需要任何电缆铺设。可以实现连续的过程监控，甚至是远程监控，因为这可以避免减压阀出现操作错误和篡改。

接下来，我们将向您展示手动或半自动测试的优势。或者单击此处直接跳转至･Festo･解决方案。

过滤器完整性测试效率的比较

手动测试的缺点

在许多情况下，保压测试仍然手动实施。这是传统的方法：手动打开和关闭所有阀。施加的压力也必须手动设定。记录、评估和监控也是手动完成。然而，这种方法有相当大的缺点。除了必需的人工劳动之外，记录数据也是一个费力的过程。除此之外，过程容易出错，并且难以集成到控制系统中。

作为居间解决方案的半自动化过程

一些水处理系统已经实现了半自动化。这意味着保压测试中的许多步骤不再需要手动启动和执行。压力值也是用可编程逻辑控制器自动测量。然而，压力的调节通常仍需手动完成。

自动化解决方案的优势

由･Festo･CPX/MPA･提供的完全自动化，通过将现场设备连接到输入/输出卡，很容易在可编程逻辑控制器层实现集成。这意味着所有过程步骤全部自动化实施。借助集成的功能，可以在现场直接调节和测量压力。

Integrated solution CPX/MPA from Festo

Festo offers you a solution for ultrafiltration systems that integrates the pressure retention test as a function on the I/O system: the CPX/MPA, a modular electrical terminal (CPX) with integrated pneumatics (MPA). The compact system is installed decentrally in the system and can be used with all common fieldbus protocols, making it easy to integrate into the higher-order centralised control system. Alternatively, a local, autonomous PLC controller can also be installed decentrally via the control module CEC that can be integrated into the CPX/MPA. This also means that cabling is kept to a minimum. The system guarantees continuous process monitoring, even remotely, and protects the pressure regulation from operating errors and tampering.

Pressure sensing is carried out via an analogue input card CPX-4AE-P-xx with which you can measure the pressure in the tubing via a direct supply port. The setting defined in the PLC directly resets a proportional pressure regulator that is integrated on the CPX/MPA, As a result, you don’t need a separate regulator or a pressure sensor in the field. Solenoid shut-off valves, which prevent raw water from entering the pneumatic part, are also controlled via the digital output cards integrated into the CPX.

The CPX/MPA can even take on other system functions. These include pilot valves for shut-off process valves, analogue output cards for control valves, digital input cards for position feedback of the process valves or analogue input cards for process sensors.

Benefits of automation with CPX/MPA

By combining electric and pneumatic components into one I/O system, Festo is able to offer an innovative solution for ongoing ultrafiltration integrity tests. This solution offers benefits to both operators and design engineers of water treatment systems:

Integration: By directly connecting the pressure regulator, pressure sensing and the digital outputs via a backplane bus, cabling is kept to a minimum. Tubing and an electrical signal cable are only needed for the shut-off valve.
Safety: The pressure level is defined using the PLC. Compared to manually adjusting the pressure, this protects the system against operating errors by system personnel. Safety is further increased if the CPX/MPA is installed in a closed control cabinet.
Efficiency: The correct pressure setting can be reproduced perfectly.
Monitoring: The pressure at the individual membrane modules can be easily sensed via terminals.
Autonomy: As a decentralised PLC function, CEC provides an autonomous system that functions reliably, even in the event of fieldbus errors.
Management: Data can simply be gathered and evaluated using the higher-order PLC or decentrally via Festo SCADA on the CPDX. That also applies to remote access via the Internet or mobile phone network.

And, as already mentioned, the CPX/MPA can also integrate additional solutions.