工业化自动多层翻板式豆粕固态发酵床的设计与试验

Design of automatic multi-layer tumbling horizontal fermentation bed and fermentation experiment

传统固态发酵条件难以控制、工业放大困难、能耗高、占地面积大,不能实现工业化流水线自动生产,更不能适应目前发酵行业规模化发展的需要。为了解决这些问题,运用现代工业设计理念,结合机械化及自动化控制技术,设计了可进行灭菌、接种、拌料、发酵的固态发酵装置。以此装置为基础,形成了集原料预处理、配料、发酵、干燥为一体的固态发酵生产系统,现已成功投产。以豆粕为原料,采用设计的生产线进行豆粕酶解发酵试验。在固态发酵期间,发酵相对湿度控制在38%-42%,而发酵24 h后,温度能稳定在37℃左右,适合微生物生长。发酵72 h结束后,饲料中酸溶性蛋白质量分数相对提高了21.2%,KOH溶解度从57.19%提高到了77.45%。结果表明：豆粕酶解发酵饲料的各项参数满足企业标准,产品质量优良。发酵过程中装置运行稳定,生产规模大,单批次最大生产量为10 t,满足工业化生产需要。该装置机械自动化水平高,可以连续批量生产,适用于生物饲料、生物肥料、生物色素、生物农药、生物燃料、生物酶制剂等多个领域。

To achieve high-value bio-products, solid-state fermentation（SSF） is a sustainable alternative for bio-based processes, in which agro-industrial by-products may be used as culture media or substrates. As a traditional fermentation technology, it has some disadvantages in condition control, industrial enlargement, energy consumption and large floor area, which make it difficult to obtain industrial production line and adapt to the large-scale developmental need of the fermentation industry. In order to solve these problems, using the concept of modern industrial design combined with the mechanized and automatic control technology, the solid fermentation equipment for sterilization, inoculation, mixing and fermentation was designed. Based on this device, the solid fermentation production system which integrates raw material pre-treatment, batching, fermentation and drying, has been formed and successfully put into operation. As the core of production system, the solid fermentation equipment is composed of a scraper feeder, a buffer outlet, a scraper conveyor of the discharge hole and a fermentation chamber with the shape of square column, which is divided into 10 layers（feeder layer is on the top, discharge layer in bottom and 8 fermentation bed layers in the middle） and has 30 m in length, 3 m in width and an area of 50 m2 covered. The materials access to the scraper feeder automatically from hoist hopper, and spread automatically and evenly into the fermentation bed through pendulous feeder. The bottom of each layer is composed of a plurality of platform trap doors which can achieve a 360° forward or reverse turning through computer-controlled cylinder drive. In the fermentation bed, the platform trap doors have turned over one by one from left to right, and the process can be repeated several times until the materials have no residue in the platform trap door. The materials can be transferred effectively from the upper layer to the lower layer, and this process can realize automatic control of temperature and humidity. Using soybean meal as raw material, the experiment of biological feed fermentation was carried out with the system. During the process of fermentation, the moisture of material varied within 38%-42% and the temperature could maintain at 37 ℃, which created a good environment for microbial growth; the moisture and crude protein content could meet the requirements of the product. After 72 h fermentation, the content of acid soluble protein of the feed was increased by 21.2% relatively, and the protein solubility in KOH solution increased from 57.19% to 77.45%. Results showed that the parameters of biological feed met the enterprise standard and the product quality was excellent; the stable operation of the device and large-scale production（production capacity of single batch was 10 t） could meet the needs of industrial production during the process of fermentation. The device has high mechanical automation level and continuous production capacity, which are suitable for the preparation of biological feed, biological fertilizer, biological pigment, biological pesticide, biological fuel and biological enzyme and other fields. As the largest automatic SSF production line, the device can not only ferment biomass materials on a large scale, but also be suitable for the production of a variety of products. It has the features of high degree of automation, less pollution and low energy consumption, which can promote significantly biomass conversion industry in China.