Application of frequency converter in paper industry

Application of frequency converters in the paper industry

The paper industry is a load of fans and pumps Large, and the running time of this type of load is continuous. According to the actual working conditions, each manufacturer needs to adjust the load of the fan and the pump to different degrees. This makes the application of ACI inverter in the industry bring great economic benefits to the enterprise. ACI frequency conversion power saving has a unique power saving function. Based on years of accumulated experience, our company has summarized the power saving analysis of frequency conversion power saver in paperless applications.

1. Application of the production line Old-fashioned paper machines generally use the total shaft drive, which has the following disadvantages:

(1) Low efficiency, only 60%-70%;

(2) Belt drive The accuracy is poor, the time is long, and the belt slips. The paper is not accurate. The web is broken, and the spare parts of the belt are highly used;

(3) The web is longitudinally and laterally contracted at the wire portion and the press portion, and both parts are shrunk during drying, so the paper machine The linear velocity of each part should be slightly different;

(4) The press section has a diameter of 6% throughout the life, so the linear velocity does not change. The total shaft drive, regardless of the DC motor or slip motor has poor adaptability to the above inherent defects, if the company's computer synchronization, sub-step frequency control system, the above shortcomings can be overcome, and save more than 20% of electrical energy.

2. Rewinding machine Rewinding machine is an important part of the paper mill system. Generally, the original rewinding machine is controlled by DC motor or electromagnetic speed regulating motor. The DC speed-regulating motor has a high failure rate, and the carbon brush is often replaced, and the maintenance cost is large. The slip speed regulating motor is a kind of motor that consumes electric energy, has soft mechanical characteristics, small speed regulation range and poor smoothness. If AC motor frequency conversion speed control is adopted, not only the production efficiency is improved, but also the energy consumption is reduced, and it has strong anti-interference ability, high power supply voltage, large single machine capacity, strong environmental adaptability, self-diagnosis and protection functions and convenient maintenance. This greatly reduces the maintenance cost and achieves the ideal power saving effect.

3. Boiler drums and induced draft fans vary according to the amount of steam required by the workshop. The air volume changes at any time, and the air volume adjustment is realized by adjusting the damper baffle. This way, the air volume adjustment method not only reduces the efficiency of the fan, but also causes a lot of power consumption to be blocked. On the board, it is a pity. Moreover, the boiler control room generally has a wide drum and an induced draft fan, and the operation is very inconvenient and cannot be properly adjusted. If ACI frequency converter is used for closed-loop stepless speed regulation, the air volume of Peng, lead and fan can be automatically adjusted to make the boiler burn in a good state, so that the consumption of coal or oil can be reduced to small, and the ideal power saving effect can be achieved.

4. Constant pressure control of the water supply system The water supply system of the paper mill is the lifeline of the enterprise, and the fair water supply can reduce unnecessary energy consumption for the enterprise. If the frequency conversion automatic constant pressure control is adopted, the pump unit adopts the advanced microcomputer control direct (DLT) and pressure transmitter and ACI variable frequency speed control technology to form a closed loop constant pressure water supply system, which can change the motor speed. As the motor speed decreases, the motor current also drops, which results in the desired power savings.