Circulating oxygen supply system of black tea fermentation machine

The utility model discloses a black tea fermentation machine circulation oxygen supply system which comprises a fermentation box, oxygen supply equipment and a heat exchange mechanism, the oxygen supply equipment is communicated with an oxygen delivery pipeline, one end of the oxygen delivery pipeline penetrates through the heat exchange mechanism and vertically extends towards the upper left portion of the fermentation box, and a tea leaf placing plate, a tea leaf placing plate, a tea leaf placing plate and a tea leaf placing plate are sequentially arranged in the fermentation box from top to bottom. A plurality of through holes are formed in the tea placing plate, screens are arranged in the through holes, the screens are flush with the upper surface of the tea placing plate, a trumpet-shaped rectangular container is arranged below the tea placing plate, and oxygen conveying branch pipes are arranged in the rectangular container. According to the circulating oxygen supply system of the black tea fermentatio