Design Of 30000 Ton/a Yoghurt Plant

Dairy industry is getting flourishing nowadays. As a result, more and more milk plants are under designing. This design was conducted for the yoghurt plant in Wuxi of Weiwei Group. Mainly works conducted were as follows: Process identification and verification; Workshop area graphic design; Material and heat balance calculation and related equipments selection; Major equipments selection; Water, electricity, steam consumption calculation, piping selection in main workshop; impact on the environment and wastewater treatment, Technical economy analysis.The producing line with a production capacity of 30,000 t/a yogurt was determined. An imported antibiotics rapid detector and a somatic and all milk composition analyzer were used to strengthen quality control of raw milk. Four 30 tons milk tanks were used for raw milk storage, separately storing and mixed producing properly according to the composition of raw milk to maximize the benefits. A pre-sterilization process was conducted to keep the safety of raw milk storage, and to ensure the safety of the product.The protein content was set as 2.5% according to GB2746-1999. It was figured out that raw milk content was 85% in final products, sugar 7%, water (stabilizer included) 8%. According to raw milk and product standardization calculation, materials consumption was determined, which provided a base to equipments selection, heat consumption calculation, piping design and so on.Plate heat exchanger was selected as cooling, heating, and sterilizing equipment according to principals of heat transference. Quantity of heat transference in different sections was figured as follows: 972500 kJ/h in raw milk cooling section, 700200kJ/h in raw milk standardization, 700200 kJ/h in homogenization and sterilization section, 560160kJ/h in fermented milk cooling section. Proper heat exchangers were selected with big heat exchanging surface, good heat exchanging efficiency and high heat recruitment efficiency, heat utilization rate was up to 63.8%.The largest water, electricity, steam consumption quantity were determine relatively as follows: 70T/h, 750kw, 6500kg/h according to the producing process, material balance and heat balance calculation and daily output. Various diameters of pipelines were also determined as follows: tap water pipelines DN100, chilling water pipelines DN76, steam pipelines DN125, cleaning water pipelines DN80.Following the strategy of sustainable development perspective, more attention was payed to protect the environment, a CIP system was introduced, which separated, recycled and reused cleaning water from different sections greatly reduced the cost of wastewater treatment. Anaerobic digestion method was conducted for wastewater treatment with a processing quantity of 200t/d, which provided conditions for the follow-up development the plant and avoided re-investment.A technical economy analysis was conducted. The results were as follows: total investment was 1.915 million yuan, asset profit margin 39.5% and sales profit margin 5.4%, profit and loss balance point was 11.8% of the designed production capacity, production capacity profit margin was 3.536 thousands tons.