1Various type: can be satisfied with request of various users also can be designed as required by users A : Two tank method: As two stage propagation ,the yeast can be multiplied by 10 times, the effective volume of two stage yeast system is respectively as follows:200L-2000L,400L-4000L,600L-6000L Both the two stage yeast tank can be heated and cooled, and can be used as yeast culture storage vessels too.B three-tank method :As three stages propagate ,the yeast can be multiplied by five times, the effective volume of three stage yeast system is respectively as follows:200L-1000L-5000L;400L-2000L-10000L;600L-3000L-15000L