Variable frequency starting device of digester stirring equipment

Abstract

The invention discloses a variable frequency starting device of digester stirring equipment. The device comprises a digester, a variable frequency motor and a control cabinet, wherein the variable frequency motor is arranged on the digester and a drive end facing downwards of the variable frequency motor is connected with stirring paddles, the variable frequency motor is connected with a frequencyconverter in the control cabinet, and forward and reverse rotation and self-inspection before delayed start of the variable frequency motor are controlled by two contactors and a delay device; two radiating fans are arranged on the control cabinet; the frequency converter sets frequency curve conversion time from start to normal operation in advance, when the stirring equipment is started, the frequency converter conducts self-inspection after being powered on, and the frequency converter is ordered to operate according to the set starting frequency in the set delay time, and the variable frequency motor drives the stirring paddle to rotate in a low speed and large torque manner, and works after the frequency reaches the rated frequency curvilinearly within the set time. By using the control function of the frequency converter, the rotating speed of the motor can be adjusted in a larger range, mechanical performance of the motor can also be improved, and great significance is providedfor reducing energy consumption and improving mixing efficiency of a mixer.

Description

technical field [0001] The invention relates to a track fixing device of a radial mud scraper, in particular to a frequency conversion starting device for stirring equipment of a digestion tank. Background technique [0002] In the sludge treatment, the mixer is widely used in the homogenization and dispersion process of the sludge in the digester. Most of the mixers are high-power electrical equipment, which operate periodically and intermittently. The drive motor needs to be started frequently. Hysteresis and inertia, it takes several seconds for the slurry to move from static to stable. In this unsteady state, the resistance of the sludge acting on the paddle is very large, and the motor will be severely overloaded for a short time, which will affect the life of the motor. At the same time, the short-term overload current is very large, almost four times more, the power loss is large and the efficiency of the motor is extremely low, which can easily cause the power line t...

AI Technical Summary

Problems solved by technology

[0002] In the sludge treatment, the mixer is widely used in the homogenization and dispersion process of the sludge in the digester. Most of the mixers are high-power electrical equipment, which operate periodically and intermittently. The drive motor needs to be started frequently. Hysteresis and inertia, it takes several seconds for the slurry to move from static to stable. In this unsteady state, the resistance of the sludge acting on the paddle is very large, and the motor will be severely overloaded for a short time, thus affecting the life of the motor.

At the same time, the short-term overload current is very large, almost four times more, the power loss is large and the efficiency of the motor is extremely low, which can easily cause the power line to age, and the transformer is overloaded and burned, so it causes a certain amount of power loss, and there is even a hidden danger of overload and fire.

In addition, the existing mixers generally do not have a speed change device, and it is difficult to achieve the best mixing efficiency when the physical parameters of the raw materials change and require different mixing speeds

Images