Application of FD5000 in paper mills
The pulper is a crucial piece of equipment in the initial stage of the papermaking process. It uniformly mixes recyclable paper with water, and after mixing and agitation, they become pulp.
Traditionally, paper mills directly use grid electricity to drive the pulper. This method has many drawbacks, such as high inrush current during startup, inability to be automatically controlled via distributed control systems (DCS) or computer systems, and susceptibility to clogging by plastics. These problems have long plagued paper mills.
With the development of frequency converter technology, many paper mill customers have realized that using frequency converters to drive pulpers is far superior to the previous methods. One overseas paper mill is a very large factory with an average paper production capacity of approximately 1000 tons per day. It is now upgrading its existing system.
Implementation Plan
The pulper's parameters are 6kV, 710kW. Based on the customer's requirements, we selected the FD5000 series frequency converter. The specific model of this frequency converter is FD5000-6/900F-1A, which adopts a one-to-one automatic configuration. This ensures automatic switching to the mains frequency in the event of a major frequency converter failure, preventing uninterrupted operation of the load. It also avoids total production line shutdowns due to a single point of failure in the frequency converter, extending the overall lifespan of the equipment and reducing unplanned downtime losses. The main circuit diagram of the equipment is shown below.
Application advantages
Using a frequency converter offers the following advantages:
1. Soft start: The pulper speed can be adjusted from 0 to rated speed, and the acceleration time can be customized to customer needs.
2. Easy DCS control: It features both digital and analog connectivity, making control convenient.
3. Low harmonics: It does not cause harmonic pollution to the motor, effectively reducing motor heat generation and improving the input power factor.
4. Reduced downtime and maintenance losses, saving significant maintenance costs.
5. Flexible operation direction: When customers find the pulper clogged, the reverse jogging function can be used. After running in reverse for a few seconds, the pulper resumes forward operation.
