airport was built during the war, but for some reason it could not be used then. Last year, however, it came into use. Over a hundred people must have been driven away from their homes by the noise. I am one of the few people left. Sometimes I think this house will be knocked down by a passing plane. I have been offered a large sum of money to go away, but I am determined to stay here. Everybody says I must be mad and they are probably right.Lesson22 A glass envelope 玻璃信封My daughter, Jane, never dreamed of receiving a letter from a girl of her own age in Holland. Last year, we were travelling across the Channel and Jane put a piece of paper with her name and address on it into a bottle. She threw the bottle into the sea. She never thought of it again, but ten months later, she received a letter from a girl in Holland. Both girls write to each other regularly now. However, they have decided to use the post-office. Letters will cost a litt1e more, but they will certainly travel faster. Lesson23 A new house 新居I had a letter from my sister yesterday. She lives in Nigeria. In her letter, she said that she would come to England next year. If she comes, she will get a surprise. We are now living in a beautiful new house in the country. Work on it had begun before my sister left. The house was completed five months ago. In my letter, I told her that she could stay with us. The house has many large rooms and there is a lovely garden. It is a very modern house, so it looks strange to some people. It must be the only modern house in the district.Lesson24 It could be worse 不幸中之萬(wàn)幸I entered the hotel managers office and sat down. I had just lost &50 and I felt very upset. I left the money in my room, I said, and its not there now. The manager was sympathetic, but he could do nothing. Everyones losing money these days, he said. He started to complain about this wicked world but was interrupted by a knock at the door. A girl came in and put an envelope on his desk. It contained &5o. I found this outside this gentlemans room she said. Well, I said to the manager, there is still some honesty in this world !lesson25 Do the English speak English? 英國(guó)人講的是英語(yǔ)嗎？I arrived in London at last. The railway station was big, black and dark. I did not know the way to my hotel, so I asked a porter. I not only spoke English very carefully, but very clearly as well. The porter, however, could not understand me; I repeated my question several times and at last he understood. He answered me, but he spoke neither slowly nor clearly. I am a foreigner, I said. Then he spoke slowly, but I could not understand him. My teacher never spoke English like that! The porter and I looked at each other and smiled. Then he said something and I understood it. Youll soon learn English! he said. I wonder. In England, each man speaks a different language. The English understand each other, but I dont understand them ! Do they speak English ?lesson26 The best art critics 最佳美術(shù)評(píng)論家I am an art student and I paint a lot of pictures. Many people pretend that they understand modern art. They always tell you what a picture is about. Of course, many pictures arc not about anything. They are just pretty patterns. We like them in the same way that we like pretty curtain material. I think that young children often appreciate modern pictures better than anyone else. They notice more. My sister is only seven, but she always tells me whether my pictures are good or not. She came into my room yesterday. What are you doing ? she asked. Im hanging this picture on the wall, I answered. Its a new one. Do you like it ? She looked at it critically for a moment. Its all right, she said, but isnt it upside-down ? I looked at it again. She was right! It was!Lesson27 A wet night 雨夜Late in the afternoon, the boys put up their tent in the middle of a field. As soon as this was done, they cooked a meal over an open fire. They were all hungry and the food smelt good. After a wonderful meal, they told stories and sang songs by the camp fire. But some time later it began to rain. The boys felt tired so they pet out the fire and crept into their tent. Their sleeping-bags were warm and comfortable, so they all slept soundly. In the middle of the night, two boys woke up and began shouting. The tent was full of water! They all leapt out of their sleeping-bags and hurried outside. It was raining heavily and they found that a stream had formed in the field. The stream wound its way across the field and then flowed right under their tent!Lesson28 No parking 禁止停車Jasper White is one of those rare people who believes in ancient myths. He has just bought a new house in the city, but ever since he moved in, he has had trouble with motorists. when he returns home at night, he always finds that someone has parked a car outside his gate. Because of this, he has not been able to get his own car into his garage even once. Jasper has put up No Parking signs outside his gate, but these have not had any effect. Now he has put an ugly stone head over the gate. It is one of the ugliest faces I have ever seen. I asked him what it was and he told me that it was Medusa, the Gorgon. Jasper hopes that she will turn motorists to stone. But none of them has been turned to stone yet!Lesson29 Taxi! 出租汽車！Captain Ben Fawcett has bought an unusual taxi and has begun a new service. The taxi is a small Swiss aeroplane called a Pilatus Porter. This wonderful plane can carry seven passengers. The most surprising thing about it, however, is that it can land anywhere: on snow, water, or even on a ploughed field. Captain Fawcetts first passenger was a doctor who flew from Birmingham to a lonely village in the Welsh mountains. Since then, Captain Fawcett has flown passengers to many unusual places. Once he landed on the roof of a block of flats and on another occasion, he landed in a deserted car park. Captain Fawcett has just refused a strange request from a businessman. The man wanted to fly to Rockall, a lonely island in the Atlantic Ocean, but Captain Fawcett did not take him because the trip was too dangerous.Lesson30 Football or polo? 足球還是水球？The Wayle is a small river that cuts across the park near my home. I like sitting by the Wayle on fine afternoons. It was warm last Sunday, so I went and sat on the river bank as usual. Some children were playing games on the bank and there were some people rowing on the river. Suddenly, one of the children kicked a ball very hard and it went towards a passing boat. Some people on the bank called out to the man in the boat, but he did not hear them. The ball struck him so hard that he nearly fell into the water. I turned to look at the children, but there werent any in sight: they had all run away! The man laughed when he realized what had happened. He called out to the children and threw the ball back to the bank. Lesson31 Success story 成功者的故事Yesterday afternoon Frank Hawkins was telling me about his experiences as a young man. Frank is now the head of a very large business company, but as a boy he used to work in a small shop. It was his job to repair bicycles and at that time he used to work fourteen hours a day. He saved money for years and in 1938 he bought a small work-shop of his own. During the war Frank used to make spare parts for aeroplanes. At that time he had two helpers. By the end of the war, the small work-shop had become a large factory which employed seven hundred and twenty-eight people. Frank smiled when he remembered his hard early years and the long road to success. He was still smiling when the door opened and his wife came in. She wanted him to repair their sons bicycle! Lesson32 Shopping made easy 購(gòu)物變得很方便People are not so honest as they once were. The temptation to steal is greater than ever before-especially in large shops. A detective recently watched a well-dressed woman who always went into a large store on Monday mornings. One Monday, there were fewer people in the shop than usual when the woman came in, so it was easier for the detective to watch her. The woman first bought a few small articles. After a little time, she chose one of the most expensive dresses in the shop and handed it to an assistant who wrapped it up for her as quickly as possible. Then the woman simply took the parcel and walked out of the shop without paying. When she was arrested, the detective found out that the shop-assistant was her daughter. The girl gave her mother a free dress once a week !lesson33 Out of the darkness 沖出黑暗Nearly a week passed before the girl was able to explain what had happened to her. One afternoon she set out from the coast in a small boat and was caught in a storm. Towards evening, the boat struck a rock and the girl jumped into the sea. Then she swam to the shore after spending the whole night in the water. During that time she covered a distance of eight miles. Early next morning, she saw a light ahead. She knew she was near the shore because the light was high up on the cliffs. On arriving at the shore, the girl struggled up the cliff towards the light she had seen. That was all she remembered. When she woke up a day later, she found herself in hospital.Lesson34 Quick work 破案“神速”Ted Robinson has been worried all the week. Last Tuesday he received a letter from the local police. In the letter he was asked to call at the station. Ted wondered why he was wanted by the police, but he went to the station yesterday and now he is not worried any more. At the station, he was told by a smiling policeman that his bicycle had been found. Five days ago, the policeman told him, the bicycle was picked up in a small village four hundred miles away. It is now being sent to his home by train. Ted was most surprised when he heard the news. He was amused too, because he never expected the bicycle to be found. It was stolen twenty years ago when Ted was a boy of fifteen !Lesson35 Stop thief! 捉賊！Rov Trenton used to drive a taxi. A short while ago, however, he became a bus-driver and he was not regretted it. He is finding his new work far more exciting. When he was driving along Catford Street recently, he saw two thieves rush out of a shop and run towards a waiting car. One of them was carrying a bag full of money. Roy acted quickly and drove the bus straight at the thieves. The one with the money got such a fright that he dropped the bag. As the thieves were trying to get away in their car, Roy drove his bus into the back of it. While the battered car was moving away, Roy stopped his bus and telephoned the police. The thieves car was badly damaged and easy to recognize. Shortly afterwards, the police stopped the car and both men were arrested. Lesson36 Across the Channel 橫渡海峽Erna Hart is going to swim across the English Channel tomorrow. She is going to set out from the French coast at five oclock in the morning. Erna is only fourteen years old and she hopes lo set up a new world record. She is a strong swimmer and many people feel that she is sure to succeed. Ernas father will set out with her in a small boat. Mr Hart has trained his daughter for years. Tomorrow he will be watching her anxiously as she swims the long distance to England. Erna年產(chǎn)10萬(wàn)噸酸奶設(shè)計(jì)說(shuō)明書(shū)目錄一、設(shè)計(jì)說(shuō)明書(shū)第一章 總論第一節(jié) 前言1第二節(jié) 建設(shè)規(guī)模及產(chǎn)品方案2第三節(jié) 廠址選擇概述4第四節(jié) 總平面布置情況5第二章 工藝設(shè)計(jì)第一節(jié) 工藝流程設(shè)計(jì)6第二節(jié)物料衡算11第三節(jié)車間設(shè)備選型14第四節(jié)主要生產(chǎn)車間設(shè)計(jì)15二、附件圖1總平面設(shè)計(jì)圖附圖1圖2設(shè)備工藝流程圖附圖2圖3生產(chǎn)車間設(shè)備布置圖附圖3表1設(shè)備選擇表17表2物料衡算表17一、設(shè)計(jì)說(shuō)明書(shū)第一章 總論第一節(jié) 前言1.1 酸奶簡(jiǎn)介民以食為天，食以乳為先。牛乳自古以來(lái)即被人類飲用，牛乳的組成最為接近人乳，含有人體所需要的全部營(yíng)養(yǎng)成分，營(yíng)養(yǎng)最為均衡，在人們的膳食結(jié)構(gòu)中具有其他食品無(wú)法替代的地位和作用。由鮮牛乳發(fā)酵成的酸乳由于其豐富的營(yíng)養(yǎng)、特殊的風(fēng)味、爽滑的質(zhì)構(gòu)和良好的生理功能，備受人們青睞。聯(lián)合國(guó)糧農(nóng)組織（FAO）、世界衛(wèi)生組織（WHO）與國(guó)際乳品聯(lián)合會(huì)（IDF）于1977年對(duì)酸乳作出如下定義：酸乳，即在添加（或不添加）乳粉（或脫脂乳粉）的乳（殺菌乳或濃縮乳）中，由保加利亞乳桿菌和嗜熱乳酸鏈球菌進(jìn)行乳酸發(fā)酵制成的凝乳狀產(chǎn)品，成品中必須含有大量的、相應(yīng)的活性微生物。通常根據(jù)酸乳成品的組織狀態(tài)來(lái)進(jìn)行分類，具體可分為凝固型酸乳（發(fā)酵過(guò)程在包裝容器中進(jìn)行，從而使成品因發(fā)酵而保留其均勻一致的凝乳狀態(tài)）、攪拌型酸乳（成品先發(fā)酵后灌裝而得，發(fā)酵后的凝乳已在灌裝前和灌裝過(guò)程中攪碎而成黏稠且均勻的半流動(dòng)狀態(tài)）和飲用型酸乳（類似攪拌型酸奶，但包裝前凝塊被分散成液體）。飲用酸乳制品對(duì)身體有很多益處，乳中許多成分具有很高的營(yíng)養(yǎng)價(jià)值，而且微生物菌群產(chǎn)生的許多代謝產(chǎn)物對(duì)人體也極為有益。營(yíng)養(yǎng)作用：牛奶中乳糖經(jīng)乳酸菌發(fā)酵，其中20%30%被分解為葡萄糖和半乳糖。前者進(jìn)一步轉(zhuǎn)化為乳酸或其他有機(jī)酸，這些有機(jī)酸有益于身體健康；后者被人吸收利用，可參與幼兒腦苷脂和神經(jīng)物質(zhì)的合成，并有利于提高乳脂肪的利用率。牛奶中的蛋白質(zhì)經(jīng)發(fā)酵作用后，乳蛋白變成微細(xì)的凝乳粒，易于被人消化吸收。酸奶中的磷、鈣和鐵易被吸收，有利于防止嬰兒佝僂病和老人骨質(zhì)疏松病。牛奶中的脂肪經(jīng)乳酸菌作用后，發(fā)生解離或酯鍵被破壞，易于被機(jī)體吸收。發(fā)酵過(guò)程中，乳酸菌還會(huì)產(chǎn)生人體所必需的維生素B1、維生素B2、維生素B6、維生素B12、煙酸和葉酸等營(yíng)養(yǎng)物質(zhì)。緩解乳糖不耐癥：乳酸菌產(chǎn)生的乳糖酶能降解牛奶中的乳糖，因此乳糖不耐癥患者飲用酸奶就不會(huì)出現(xiàn)飲用牛奶時(shí)發(fā)生的乳糖不耐癥，如腹脹、腹痛、腸道痙攣、下瀉等。整腸作用：人體腸道內(nèi)存在有益菌群和有害菌群。在人體正常情況下，前者占優(yōu)勢(shì)；當(dāng)人患病時(shí)，有害菌群占優(yōu)勢(shì)。飲用酸奶可以維持有益菌群的優(yōu)勢(shì)。抑菌作用：嗜熱乳桿菌和雙歧桿菌不受胃液和膽汁的影響，可以進(jìn)入腸道，在腸道內(nèi)存留較長(zhǎng)時(shí)間。這兩種乳酸菌以及在這些乳酸菌影響下生長(zhǎng)起來(lái)的腸道中的其他乳酸菌，可以產(chǎn)生嗜熱乳菌素等抗菌物質(zhì)，這些物質(zhì)大都對(duì)大腸桿菌、沙門氏菌和金黃色葡萄球菌等有明顯的抑菌作用。改善便秘作用：進(jìn)入腸道中的活的乳酸菌能產(chǎn)生乳酸、醋酸等有機(jī)酸。這些有機(jī)酸有刺激腸道，加強(qiáng)蠕動(dòng)的作用，故可以改善便秘。降低膽固醇：牛乳中的乳清酸、乳糖和鈣，以及酸奶中存在的羥基戊二酸都有降低膽固醇的作用。抗癌作用：酸奶有抑制3種酶的活性作用，這些酶能引起癌變。另外，酸奶還能激活巨噬細(xì)胞，抑制腫瘤細(xì)胞，從而起到抗癌作用。1.2 酸奶的發(fā)展前景盡管目前我國(guó)的乳業(yè)市場(chǎng)不斷擴(kuò)大，乳品消費(fèi)觀念在不斷提高，但我國(guó)年人均乳制品不足20kg的消費(fèi)量與世界人均100kg、發(fā)達(dá)國(guó)家人均140kg的消費(fèi)量相比還有較大差距。中國(guó)的乳品消費(fèi)在整體上并沒(méi)有進(jìn)入完全理性的軌道。由于營(yíng)養(yǎng)知識(shí)的欠缺，許多人不了解乳品對(duì)改善營(yíng)養(yǎng)、平衡膳食、補(bǔ)鈣和增強(qiáng)體質(zhì)的重要作用，包括對(duì)酸乳的認(rèn)識(shí)也不夠，因而市場(chǎng)占有率也不太高，不過(guò)隨著人們對(duì)酸乳營(yíng)養(yǎng)價(jià)值的認(rèn)識(shí)，人們對(duì)酸奶的態(tài)度發(fā)生了改變，市場(chǎng)占有份額也逐年增加。隨著我國(guó)居民生活水平和消費(fèi)觀念的轉(zhuǎn)變，酸奶的消費(fèi)在以后的較長(zhǎng)時(shí)間內(nèi)仍舊會(huì)保持迅速的增長(zhǎng)勢(shì)頭，這種超常的增長(zhǎng)速度在全球酸奶發(fā)展史上是非常罕見(jiàn)的，市場(chǎng)前景極為廣闊。1.3 本次設(shè)計(jì)范圍本設(shè)計(jì)主要是年產(chǎn)10萬(wàn)噸酸奶廠車間的工藝設(shè)計(jì)。設(shè)計(jì)范圍包括廠址選擇，制定產(chǎn)品方案，各產(chǎn)品工藝流程的確定，工藝論證，根據(jù)物料衡算進(jìn)行設(shè)備選型，對(duì)水、電、汽等生產(chǎn)車間必備的生產(chǎn)要素的配給和優(yōu)化，企業(yè)組織及勞動(dòng)力組成，全廠輔助設(shè)施及公用系統(tǒng)，車間生產(chǎn)工藝流程圖、車間平面布置圖、工廠總平面布置圖各一張，經(jīng)濟(jì)核算及效益分析。第二節(jié) 建設(shè)規(guī)模及產(chǎn)品方案2.1 生產(chǎn)規(guī)模年產(chǎn)10萬(wàn)噸酸奶。2.2 產(chǎn)品方案2.2.1 產(chǎn)品方案確定說(shuō)明本設(shè)計(jì)根據(jù)產(chǎn)品的種類、包裝種類和各產(chǎn)品的產(chǎn)量，并且符合生產(chǎn)向機(jī)械化、自動(dòng)化、連續(xù)化發(fā)展方向的要求，最終確定了本設(shè)計(jì)的產(chǎn)品方案。由于酸奶工廠原料基本采用奶牛當(dāng)日產(chǎn)的牛乳，并且酸奶是消費(fèi)者每日飲用的產(chǎn)品，因此酸奶工廠全年沒(méi)有停產(chǎn)時(shí)間，按照365日計(jì)算。為平衡每月生產(chǎn)的產(chǎn)量，避免出現(xiàn)部分月停產(chǎn)，部分月加工任務(wù)過(guò)于繁重，結(jié)合主要加工酸奶的品種成熟時(shí)間情況，初步安排產(chǎn)品生產(chǎn)方案如下（注每月以30天計(jì)）：其中玻璃瓶（200g/瓶）和塑料杯（125g/杯）的班產(chǎn)量為50t；屋頂包（500g/包）的班產(chǎn)量為10t；其他品種的班產(chǎn)量均為20t。表1-1 工廠日生產(chǎn)產(chǎn)品方案產(chǎn)品種類包裝包裝規(guī)格灌裝機(jī)能力產(chǎn)品名稱產(chǎn)量（噸/天）凝固型酸奶玻璃瓶200g/瓶12000瓶/小時(shí)風(fēng)味、果料酸奶 6個(gè)品種（3個(gè)/天）90攪拌型酸奶塑料杯125g/杯12000杯/小時(shí)風(fēng)味、果料酸奶 10個(gè)品種（5個(gè)/天）8520000杯/小時(shí)150g/杯9000杯/小時(shí)風(fēng)味、果料酸奶 6個(gè)品種（3個(gè)/天）40屋頂包200g/包6000包/小時(shí)風(fēng)味、果料酸奶 10個(gè)品種（4個(gè)/天）24500g/包121000g/包24合計(jì)275表1-2 年產(chǎn)100000t發(fā)酵乳制品工廠的產(chǎn)品方案一覽表產(chǎn)品名稱包裝種類一月二月三月四月五月六月七月八月九月十月十一月十二月年產(chǎn)量（t）凝固型酸奶玻璃瓶200g32850攪拌型酸奶塑料杯125g31025塑料杯150g14600屋頂包200g8760屋頂包500g 4380屋頂包1000g8760第三節(jié) 廠址選擇概述項(xiàng)目廠址選擇在蚌埠高新技術(shù)產(chǎn)業(yè)示范區(qū)，蚌埠位于東經(jīng)11712"、北緯3257"，淮河中下游，面向長(zhǎng)三角，蚌埠是安徽省最大的城市之一，也是安徽省第一個(gè)建市的地級(jí)市，同時(shí)也是安徽省經(jīng)濟(jì)命脈，全國(guó)重要的交通樞紐，經(jīng)濟(jì)腹地十分寬廣?？缰袊?guó)南北分界線，擁有千里淮河第一大港口，是京滬高速鐵路一等客站所在地、同時(shí)京滬高速鐵路由蚌埠火車原上海鐵路局蚌埠鐵路分局，現(xiàn)上海鐵路局蚌埠鐵路辦事處仍駐蚌埠。蚌埠是中國(guó)著名的水陸交通樞扭城市，也是安徽省重要的工業(yè)基地。常住人口360萬(wàn)人，其中市區(qū)人口近100萬(wàn)人。蚌埠鐵路縱橫交錯(cuò)，公路如網(wǎng)般密布，臨近淮河交通極為便利。此外示范區(qū)地勢(shì)平坦，工程基礎(chǔ)條件良好，周圍沒(méi)有污染源等不利于建廠的環(huán)境因素。廠址與原料基地之間均為高級(jí)公路相通，保證了原料采收期對(duì)運(yùn)輸時(shí)間的限制。而銷售地區(qū)也在上述中心城市，便于冷鏈運(yùn)輸和分銷，適于建酸奶加工廠。第四節(jié) 總平面布置情況項(xiàng)目占地15000m2，其中生產(chǎn)區(qū)占地6000 m2，位于廠區(qū)中心；生活區(qū)占地1500m2，位于廠區(qū)東北角。工廠坐北朝南，從南大門進(jìn)廠，豁然呈現(xiàn)在眼前的是一個(gè)橢圓形的花壇，花壇中心設(shè)置有噴泉、假山，這種色彩鮮明、動(dòng)靜結(jié)合的搭配，給人一種清新潔凈、生機(jī)盎然的感覺(jué)，烘托出項(xiàng)目產(chǎn)品新鮮、方便、衛(wèi)生的底蘊(yùn)，廠區(qū)總平面布置見(jiàn)圖1?；▔北闶钦嫉?440m2 的主生產(chǎn)車間，寬敞明亮，布置有現(xiàn)代化的生產(chǎn)線。洗手間、空氣凈化設(shè)備、衛(wèi)生隔墻等設(shè)施一應(yīng)俱全，全面適應(yīng)生產(chǎn)的需要。廠區(qū)東側(cè)是機(jī)修間和鍋爐房。廠區(qū)西側(cè)布置的是原料庫(kù)、成品庫(kù)和辦公樓、實(shí)驗(yàn)室。工廠的道路均按照工廠設(shè)計(jì)的標(biāo)準(zhǔn)進(jìn)行布置，主干道路寬6m，兩側(cè)布置有綠化帶，環(huán)繞整個(gè)廠區(qū)。并設(shè)有人行道和緩沖區(qū)，充分做到人車分離、安全生產(chǎn)。廠區(qū)的綠化帶布置合理，栽種常綠樹(shù)木和草類，使整個(gè)廠區(qū)四季如春，顯得生機(jī)盎然。廠區(qū)總平面設(shè)計(jì)圖見(jiàn)附圖1?，F(xiàn)在食品工廠大多采用輕鋼結(jié)構(gòu)的廠房，輕鋼建筑材料重量輕、建設(shè)周期短，相對(duì)建筑成本比較低，同時(shí)，輕鋼結(jié)構(gòu)廠房相對(duì)跨度大，對(duì)設(shè)備在廠房中的布置影響小，框架結(jié)構(gòu)對(duì)于不同功能分隔和以后的變更都非常的方便，因此，本設(shè)計(jì)也將采用輕鋼結(jié)構(gòu)廠房進(jìn)行設(shè)計(jì)。我國(guó)夏季多為東南風(fēng)，冬季多為西北風(fēng)，因此本設(shè)計(jì)將動(dòng)力系統(tǒng)和污水處理系統(tǒng)放置在整個(gè)廠區(qū)的東側(cè)，避免因?yàn)轱L(fēng)向的問(wèn)題影響產(chǎn)品質(zhì)量，同時(shí)根據(jù)乳制品GMP要求，本設(shè)計(jì)的廠房具有通排風(fēng)系統(tǒng)，避免外界的污染進(jìn)入到車間內(nèi)部。主車間物流為南北走向，人流為東西走向，因此，在主廠房北側(cè)設(shè)置原輔料倉(cāng)庫(kù)和容器整理中心，對(duì)原、輔料進(jìn)行儲(chǔ)存和瓶、箱等包裝容器的初步滔滔和整理.原料經(jīng)過(guò)加工處理，生產(chǎn)出的成品由主廠房南側(cè)經(jīng)過(guò)冷庫(kù)儲(chǔ)存和恒溫月臺(tái)分配后由物流配送系統(tǒng)運(yùn)送出廠。恒溫月臺(tái)能夠避免成品在分配過(guò)程中處于高溫環(huán)境，從而造成對(duì)產(chǎn)品質(zhì)量的影響。主場(chǎng)房人流方向?yàn)闁|西走向，人流經(jīng)過(guò)主廠房一次換鞋、更衣、二次換鞋、消毒池以及風(fēng)淋間后通過(guò)人流通道進(jìn)入各個(gè)生產(chǎn)崗位進(jìn)行生產(chǎn)。設(shè)計(jì)中人流路線與物流路線沒(méi)有交叉，因此能夠避免事故和操作失誤。第二章 工藝設(shè)計(jì)第一節(jié) 工藝流程設(shè)計(jì)1.1 凝固型酸奶的工藝流程鮮乳或還原乳 驗(yàn)收 預(yù)處理 奶倉(cāng)牛乳白砂糖 溶解 調(diào)配 預(yù)熱6065 1520MPa 均質(zhì) 加熱滅菌9095、35min 冷卻快速冷卻至4245直投式發(fā)酵劑 接種 灌裝直投式菌種：43 發(fā)酵46.5h 速冷速冷至1520 冷藏后熟：4冷藏過(guò)夜保持冷鏈貯存或銷售1.2 攪拌型酸奶的工藝流程 鮮牛乳 驗(yàn)收 預(yù)處理 奶倉(cāng) 牛乳白砂糖溶解調(diào)配 預(yù)熱（6065） 均質(zhì)（15MPa） 殺菌(95，5min) 冷卻(4245)直投式發(fā)酵劑 接種 發(fā)酵（終點(diǎn)pH4.6） 破乳、冷卻（1520）溶解殺菌 冷卻 混合穩(wěn)定劑、水、白砂糖 均質(zhì)（15MPa） 冷卻（1520）灌裝、冷藏保持冷鏈貯存或銷售1.3 操作要點(diǎn)說(shuō)明（1） 預(yù)處理 凈化可以除去原料乳中的雜質(zhì)，使牛乳達(dá)到最高的純凈度。為使原料乳中脂肪和無(wú)脂干物質(zhì)之間的比例關(guān)系符合制品的要求，可通過(guò)閃蒸操作調(diào)整其比例關(guān)系。（2） 預(yù)熱 預(yù)熱一方面可以殺菌，而且由于適當(dāng)加熱，可以使一部分乳清蛋白凝固，提高酪蛋白的熱穩(wěn)定性，以防止滅菌時(shí)凝固，并賦予成品以適當(dāng)?shù)酿ざ取Ｍ瑫r(shí)可以鈍化酶并降低均質(zhì)后乳脂肪球的直徑，防止均質(zhì)后的產(chǎn)品中脂肪上浮，增加產(chǎn)品的穩(wěn)定性。預(yù)熱溫度控制在6065。（3） 均質(zhì) 均質(zhì)主要是使原料充分混合均勻，阻止奶油上浮，提高酸乳的穩(wěn)定性和稠度，并保證乳脂肪均勻分布，從而獲得質(zhì)地細(xì)膩、口感良好的產(chǎn)品。均質(zhì)壓力控制在15MPa。（4） 殺菌殺菌目的在于殺滅原料乳中的雜菌確保乳酸菌的正常生長(zhǎng)和繁殖，鈍化原料乳中的天然抑制物；使乳清蛋白變性，以達(dá)到改善組織，提高黏稠度和防止成品乳清西出的目的。殺菌溫度控制在95，保溫5min進(jìn)行殺菌。（5） 冷卻 冷卻主要是為接種的需要。經(jīng)過(guò)熱處理的牛乳需要冷卻到一個(gè)適宜的接種溫度，此溫度控制在4245內(nèi)。（6） 接種 接種是造成酸乳受微生物污染的主要環(huán)節(jié)之一，因此嚴(yán)格注意操作衛(wèi)生，防止細(xì)菌、酵母、霉菌、噬菌體及其他有害微生物的污染。接種時(shí)充分?jǐn)嚢?，使發(fā)酵劑與原料乳混合均勻。（7） 發(fā)酵發(fā)酵溫度控制在4245，從而為微生物代謝提供最適的溫度環(huán)境，發(fā)酵時(shí)間2.5h3h，且期間不攪拌。發(fā)酵終點(diǎn)判定：觀察發(fā)酵乳表面的狀態(tài)，只要表面呈均勻的凝固樣，并且又少量乳清析出，即可初步判斷接近發(fā)酵終點(diǎn)，再測(cè)定pH4.6時(shí)即可停止發(fā)酵。（8） 破乳、冷卻 破碎凝膠體，使凝膠體的粒子直徑達(dá)到0.01mm0.4mm，并使酸乳的硬度和黏度及組織狀態(tài)發(fā)生變化。攪拌速度不可過(guò)快，時(shí)間不宜過(guò)長(zhǎng)。 冷卻目的是抑制乳酸菌的生長(zhǎng)、降低酶的活性、防止產(chǎn)酸過(guò)度、使酸奶逐漸凝固、降低和穩(wěn)定脂肪上浮和乳清析出的速度。將發(fā)酵乳迅速降溫至1520。（9） 混合 將經(jīng)溶解和殺菌的穩(wěn)定劑、水和白砂糖輔料與發(fā)酵乳進(jìn)行混合。（10） 均質(zhì) 使混合料液滴微細(xì)化，提高料液黏度，抑制粒子的沉淀，并增強(qiáng)穩(wěn)定劑的穩(wěn)定效果。均質(zhì)壓力控制在15MPa,均質(zhì)溫度為60左右。均質(zhì)是為了充分將添加入混合罐中的穩(wěn)定劑、水和白砂糖輔料混合均勻，從而獲得質(zhì)地細(xì)膩、口感良好的產(chǎn)品。（11） 灌裝和冷藏采用相應(yīng)灌裝機(jī)進(jìn)行灌裝后的成品置于05冷藏12h24h，進(jìn)行后熟，以產(chǎn)生良好的風(fēng)味。1.4 酸奶質(zhì)量標(biāo)準(zhǔn)表2-1 酸奶質(zhì)量標(biāo)準(zhǔn)項(xiàng)目純酸牛奶調(diào)味酸牛乳、果料酸牛乳全脂部分脫脂脫脂全脂部分脫脂脫脂色澤呈均一一致的乳白色或微黃色呈均一一致的乳白色或調(diào)味乳果料應(yīng)有的色澤滋味和氣味具有酸牛奶固有的滋味和氣味具有調(diào)味乳或果料乳應(yīng)有的滋味和氣味組織狀態(tài)組織細(xì)膩均勻，允許有少量乳清析出果料酸牛乳有果塊或果粒脂肪，%3.11.0-2.00.52.50.8-1.60.4蛋白質(zhì)，%2.92.3非脂乳固體，%8.16.5酸度，T70苯甲酸，g/kg0.030.23山梨酸，g/kg不得檢出0.23硝酸鹽（NaNO3計(jì)）mg/kg11黃曲霉毒素MI,ug/kg0.5大腸菌群MPN/100ml90致病菌（指腸道致病菌和致病性球菌）不得檢出第二節(jié)物料衡算 根據(jù)工廠設(shè)計(jì)規(guī)模、產(chǎn)品方案，通過(guò)物料平衡計(jì)算，可確定單位時(shí)間生產(chǎn)過(guò)程中主要原輔料的需求量以及水、蒸汽、能源等流量與耗量，據(jù)此就可以計(jì)算出全年主要物料、包裝材料的采購(gòu)運(yùn)輸和倉(cāng)儲(chǔ)容量。同時(shí)通過(guò)物料衡算，還可以根據(jù)計(jì)算數(shù)值經(jīng)濟(jì)合理地選擇生產(chǎn)設(shè)備，并進(jìn)行車間的工藝布置和各工序勞動(dòng)力的安排，也是進(jìn)行經(jīng)濟(jì)分析不可缺少的根據(jù)。為平衡每月生產(chǎn)的產(chǎn)量，避免出現(xiàn)部分月停產(chǎn)，部分月加工任務(wù)過(guò)于繁重，結(jié)合主要加工酸奶的品種成熟時(shí)間情況，初步安排產(chǎn)品生產(chǎn)方案如下（注每月以30天計(jì)）：根據(jù)酸奶基礎(chǔ)配方：2.1 凝固型酸奶鮮牛奶85%，蔗糖7%，穩(wěn)定劑0.5%，菌種3%，水：余量。凝固型酸奶的日產(chǎn)量為90噸，因此生產(chǎn)凝固型酸奶的原料使用量（以最高使用量）如下：鮮牛奶：90噸*85%=76.5噸