Banana screen mainly has a concave screen surface. The angle of the screen surface and the horizontal plane of the banana screen gradually decreases from the feeding end to the discharging end. Due to the large inclination angle of the screen surface at the feeding end, the running speed of the material on the screen surface is accelerated, which can improve the processing capacity of the banana screen. This is more suitable for relatively loose materials, if the viscosity of the material is larger, more water, easy to block the screen, or the material under the screen is more, the screening effect of the feed end will be affected. At the same time, it also increases the screening burden at the discharge end and affects the screening efficiency of banana screen. We provide an amplitude-decreasing banana screen, which can effectively improve the screening effect and screening efficiency of banana screen at the feed end of the banana screen box. Achieved by the following measures, banana screen is mainly composed of screen box, screen mesh, vibration excitation device and frame, etc. The screen box is installed on the frame through the vibration reduction device. The characteristics are: There is a banana shaped screen, installed in the screening box of the banana screen: The excitation device is composed of two vibrators, one vibrator is arranged in the feed end of the screening box, and the other vibrator is arranged in the discharge end of the screening box: The distance between the two vibrators is between one-third and five-sixths of the length of the screening box: The eccentric mass of the two vibrators is different, and the eccentric mass of the vibrator at the feeding end is greater than that at the discharging end, that is, the amplitude of the feeding end of the screen box is greater than that at the discharging end. The rotation direction of the two vibrators is opposite, and the action line of the vibration force passes through the center of gravity of the banana screen box. The vibration exciter of banana screen is an eccentric shaft type or eccentric block type vibrator, and an eccentric mass adjustment device with an additional eccentric block is provided to adjust the eccentric mass of the vibrator by increasing or decreasing the additional eccentric block. [0005] when the banana screen works, the two vibrators rotate at the same speed in opposite directions, respectively, driven by two electric motors. Because the eccentric mass of the two vibrators is different, the eccentric mass of the vibrator at the feeding end is larger, so the amplitude of the feeding end of the screen box is greater than the amplitude of the discharging end of the screen box. The material on the screen passes through the screen in a decreasing amplitude motion. The beneficial effect is that because the eccentric mass of the vibrator at the inlet end of the banana screen is greater than that at the outlet end, that is, the amplitude at the inlet end of the screen box is greater than that at the outlet end, the amplitude forms a decreasing trend. Due to the large inclination angle of the screen surface at the feeding end, the effect of distributing and screening at the feeding end is accelerated. The amplitude of the discharge end is smaller, and the inclination angle of the screen surface is also small, so the sifting effect of the material is significantly improved. It can be applied to the screening of materials with larger viscosity, more water content or more material under the screen.
An embodiment of the utility model is illustrated in combination with the attached drawings. Banana screen is mainly composed of screen box, screen mesh, vibration exciting device and frame, etc. The screen box is installed on the frame through the vibration damping device, and the motor of the vibration exciting device is installed on the motor support. Double banana-shaped screen is installed in the screening box of the banana screen: The vibration exciter is composed of two vibrators, one vibrator is arranged near the feeding end of the screening box, and the other vibrator is arranged near the discharging end of the screening box; the distance between the two vibrator centers is half the length of the screen box; the eccentric mass of the two vibrators is different, the eccentric mass of the inlet end vibrator is greater than the eccentric mass of the outlet end vibrator, the amplitude of the inlet end of the screen box is 10m, and the amplitude of the outlet end is 8mm. The rotation direction of the two vibrators is opposite, and the action line of the vibration force passes through the center of gravity of the banana screen box. The two vibrators of banana screen are eccentric block type vibrators, and are equipped with an eccentric mass adjustment device with additional eccentric block. The eccentric mass of the vibrator can be adjusted by increasing or decreasing the additional eccentric block.