日光温室薄膜清洗机设计及清洗效果试验

针对当前中国日光温室薄膜清洗效率低及清洗困难的问题,该文研制了一种半自动日光温室薄膜清洗机。整机包括清洗与行走部分,清洗部分主要包括直流电机、2组不同减速比减速器、清洁毛刷以及支撑滚筒,依靠拉绳收放完成升降,实现温室薄膜上下不同位置清洁;行走部分用来整体平移清洗部分,其上的放置平台采用偏心结构设计,方便清洗部分从薄膜放置到行走装置及再次清洗时移动到薄膜表面。以薄膜透光率为指标,开展了清洗速度、喷水压力与流量、刷毛长度对清洗效果影响的研究,得出合理的清洗爬升速度为2.8～5.6 m/min,喷水流量为2～3.5 L/min,毛刷接触薄膜长度为3 cm。通过对自然条件下使用3个月的新换薄膜进行试验,得到清洗后薄膜透光率最高可达90%,与同时更换未清洗薄膜相比提高15个百分点。该装置的使用在减小劳动强度的同时,提高了日光温室薄膜清洗效率、改善了棚内光照条件。

Design of film cleaning machine for solar greenhouse and its cleaning effect

Abstract: In view of the current low efficiency and difficulty of cleaning solar greenhouses in China, a semi-automatic solar greenhouse film cleaning machine was developed. The whole machine includes cleaning and walking parts. The cleaning part mainly includes DC motor, two sets of different reduction ratio reducers, cleaning brush and support rollers. The cleaning part is the core of the solar greenhouse cleaning machine. Under the forward rotation of the cleaning motor, the cleaning shaft is rotated at a high speed to drive the cleaning brush to complete the cleaning of the surface of the film. On the other hand, the climbing shaft is rotated by the speed reduction mechanism, thereby the entire cleaning section is climbed around the shaft by the pressing film ropes. The water spray pipe at the top of the cleaning part sprays water to the front of the cleaning brush, wets the film when it rises, and rinses the film when it is lowered, ensuring the cleaning effect and the cleanliness of the film after washing. The walking part mainly includes: a walking chassis, a motor drive axle, a support wheel, a guide wheel, an armrest, and a cleaning part placement platform. The walking chassis is equipped with a guide wheel to ensure that the walking part moves straight. The upper-end surface of the chassis is also equipped with a cleaning part placement platform, which adopts an eccentric structure design to ensure that the walking part is away from the film when the cleaning device is displaced; when the cleaning part enters the placement platform, the walking part fits the greenhouse keel to ensure smooth operation and improve work safety. From August 2018 to January 2019, the prototype was debugged and tested in the Science and Technology Innovation Park of Shandong Agricultural University. The solar greenhouse was a brick wall structure with a length of 40 m in East and west, a span of 10 m in North and south, and a ridge height of 5 m. Three greenhouses were used for different stages of experiments. The film cleaning performance test was carried out, and the influence of different cleaning parameters on the cleaning effect was analyzed. The results showed that the length of the cleaning brush can be set to 3 cm for the film used for three months; the reasonable speed range for the cleaning brush is 150-300 r/min. The cleaning requirement can be met for single-pass cleaning, the water pressure was 0.08 MPa, the flow rate was 3.5 L/min, and the double-pass cleaning the pressure was 0.05 MPa and the flow rate was 2 L/min. After using a new film for 3 months under natural conditions, the instantaneous transmittance of the film after cleaning was up to 90%, which was 15 percentage points higher than that without cleaning the film. The average light transmission period from 09:00 to 15:00 during the test period can be increased by 12 percentage points, and the stronger the outdoor light, the more obvious the transmittance is increased. The use of the device improves the cleaning efficiency of the solar greenhouse film and improves the illumination conditions in the shed and reducing the labor intensity.