Wheat bread production line with calculation of dough kneading machine Prima-300R

Contents

INTRODUCTION

1 PRODUCTION PROCESS

1.1 Characteristics of the food product

1.2 Manufacturing Process

1.3 Storage and Transportation

1.4 Production flow chart

2 ANALYTICAL DESIGN OVERVIEW AND DESCRIPTION

2.1 Classification and general characteristics

2.2 Patent Overview

2.3 Design Description and Technical Specification

3 DESIGN PART

3.1 Process calculation

3.2 Energy calculation

3.3 Kinematic calculation

3.4 Structural calculation

4 INSTALLATION, ADJUSTMENT AND MAINTENANCE

CONCLUSION

LIST OF SOURCES USED

Paper

Course design 68 pages, 24 figures, 4 tables, 8 sources.

Keywords: flour, bread, technology, dough kneading machine, production, calculation, adjustment, maintenance.

The object of the study is a test kneading machine Prima300P, for kneading dough.

The purpose of the project is to obtain skills in calculating and designing machines and apparatus of the processing industry, familiarization with food production technologies.

During operation, design of dough kneading machines was reviewed. Patent search was carried out. The technological process of wheat bread production is described.

Technological, energy, kinematic and structural calculations were performed according to the given initial data.

A separate section deals with safety requirements during installation, adjustment and maintenance of process equipment.

Introduction

Bread is the oldest human food that consists of several ingredients and requires a lot of work to cook. Perhaps it was the need to grow bread that forced a person to move to a settled life from hunting and gathering.

The main areas of development of the bakery industry are:

Updating and upgrading of the equipment fleet;

Application of new and improved bakery production technology;

Expansion of the range and quality improvement of bread products;

Comprehensive automation and widespread introduction of C&I and automation into production.

The development of the bakery industry is carried out on the basis of the introduction of new technology, progressive technology, an increase in the production of bread and bakery products with various additives and enhancers that increase their biological value and quality.

The development of high quality bakery products requires more efficient production and marketing activities, better communication between the producer and the consumer, the creation of an assortment that meets the modern needs of the population and the establishment of a level of prices that will allow the acquisition of bakery products by various segments of the population.

The question of baking or baking has so far remained little developed in a strictly scientific sense and, presumably, precisely because, as a question of satisfying the first urgent need, it was resolved, first of all, practically, by random observations and earlier than one could think of the scientific formulation of such issues. Recently, under the influence of the general development of large industry, bakery production has become massive, and innovations have begun to appear in the application to such mass production, chiefly aiming at increasing productivity and reducing production costs.

Management of biochemical, microbiological, colloidal and other processes is an effective way to improve the quality of food products. This fully applies to the production of one of the mass and traditional food products in our country - bread. Controlling the processes of bread baking in order to improve its quality and at the same time reduce energy consumption in its production is one way to solve an important agricultural problem.

There are more proteins in wheat flour products than in rye flour products. One part of the proteins in bread accounts for up to about eight parts of carbohydrates, which is clearly insufficient in terms of the quantitative content of protein substances. The most rational ratio of proteins, fats and carbohydrates in food is considered 1:1:5.

Due to bread, the human body 50% satisfies the need for vitamins of group B: thiamine (B1), riboflavin (B2) and nicotinic acid (PP). The presence of vitamins in bread is mainly due to the variety of flour. When grinding grain, up to 65% of vitamins are lost to flour, and the more, the higher the variety of flour. Bread from wallpaper flour is characterized by a higher vitamin content.

Production Process

1.1 Characteristics of the food product

Bread is produced in the form of piece products baked from flour dough, which is fermented. The surface of the articles is covered with a hard crust, and inside there is a soft, porous, elastically elastic flesh.

The main raw material for bread production is flour, as well as drinking water, yeast and salt. Sugar, fats and various food additives are used as additional raw materials. Bakery flour is made from powdery grains of soft wheat. The structure of such flour is loose powder. All the rest of the raw materials are converted into intermediate liquid semi-products: solutions, emulsions or suspensions.

Baking dough, as a result of kneading and fermentation, acquires the necessary acidity and physical properties for this type of bread: elasticity, shape-retaining and gas-retaining abilities, which provide the maximum volume of dough blanks supplied to baking [1].

1.2 Manufacturing Process

Preparation of bread from wheat flour can be divided into the following stages and main operations:

- preparation of raw materials for production: storage, mixing, aeration, screening and metering of flour; drinking water preparation; preparation and tempering of salt and sugar solutions, fat emulsion and yeast distribution;

- dosing of recipe components, kneading and fermentation of opara and dough;

- cutting - division of ripened dough into portions of the same mass;

- moulding - mechanical processing of dough blanks in order to give them a certain shape: spherical, cylindrical, cigar-shaped, etc.;

- proofing - fermentation of moulded dough blanks. After proofing, dough blanks can be cut (bars, city buns, etc.);

- hygrothermal processing of dough blanks and bread baking;

- cooling, rejection and storage of bread.

Reception and storage of raw materials. All raw materials supplied to bakeries must meet the requirements of the relevant GOST or specification.

Flour. Flour at its arrival and storage in bags is stacked. At the enterprise one uses non-commercial storage of flour. In case of bulk transportation and storage of flour it is placed in warehouses of bulk storage of flour. Flour is stored in special containers - silos. Silos are distributed in grades in accordance with quality indicators: it is recommended to place flour with the same or similar properties in one container. Containers for flour storage are numbered and fixed to certain varieties of flour. Complete cleaning of silos should be carried out at least once a year.

Yeast. Storage room for yeast storage shall be dry, clean, ventilated. Compressed yeast shall be stored at a temperature of 0 to + 4 ° C. It is allowed to store replacement or daily stock of pressed yeast in production under workshop conditions. If the yeast freezes before consumption, it is necessary to gradually thaw them at a temperature of 4 to 6 ° C. Pressed yeast is introduced at mixing of semi-products in the form of yeast suspension at ratio of yeast to water 1:3 - 1:4, with water temperature not exceeding 40 ° C.

Salt. Salt enters bakeries in bags and is stored in a separate room in bulk or in stalls. Salt due to hygroscopicity cannot be stored together with other products. The salt is added to the dough in the form of a solution with a concentration of 23-26% by weight. The saturated solution is prepared in salt solvents, which is then filtered and fed into production kits.

Sugar. Sugarcane delivered in bags is stored in a clean dry room with a relative humidity of 70%. Sugar is hygroscopic, so in a raw room it moisturizes. Bags of sugar are laid (on racks) in stacks of 8 rows in height.

Fat products. Vegetable oil, margarine, animal oil and other solid fats are used as fat additives in baking. At bakeries with a daily capacity of more than 45 tons for the acceptance and storage of vegetable oil there should be metal containers.

Flour, yeast and other raw materials entering the bakery are subjected to laboratory analysis, the purpose of which is to verify the compliance of the raw materials with standards and establish their bakery properties.

Preparation of raw materials for production. Based on the analysis of individual batches of flour in the warehouse, the workers of the bakery laboratory make a roll of flour. It is customary to call a mixture of separate batches of flour of one grade by rolling flour in bakery production.

Flour preparation consists in mixing of individual batches, their sieving and magnetic cleaning. Flour is mixed in order to improve bakery properties of one batch due to another. So, flour with weak gluten is mixed with strong; flour that darkens during processing - with non-darkening, etc.

Pressed yeast is released from packaging, coarsely crushed and homogeneous suspension is prepared in 30-35 ° C water.

Salt and sugar are dissolved in water in tanks with stirrers at a temperature of about 40 ° C to a solution concentration of 55%, and then pumped to collectors.

Hard fats are melted in tanks with a water jacket and a stirrer. The temperature of margarine should be no more than 40-45 ° C, otherwise it will be stratified into fat and water and unevenly distributed in the test. Liquid fats are screened.

Water. The optimal water temperature for kneading dough is 40 - 42 °.

Preparation of dough. Methods of wheat dough preparation. The main methods of preparing wheat dough are non-dough and dough.

In a safe method, the dough is kneaded into one take at once from all the raw materials provided by the recipe. Compressed yeast consumption is 2 - 2.5%, fermentation duration is 2.5 hour. In the process of fermentation, 2 - 3 coats are carried out, the last - 30 - 40 minutes before dough cutting.

The opar method consists of two stages - preparation of opara and dough. 50% of the total amount of flour, up to 70% of water and the entire amount of yeast (0.5-1%) are taken for preparation of opara. Duration of sponge fermentation is 3.5 - 4.5 hours. Dough is kneaded on the finished opar, adding the remaining flour, water and the rest of the raw materials. The dough wanders for 1 - 1.5 hours. During fermentation dough is subjected to one or two wraps.

The dough preparation method is long, but due to the deeper process of ripening processes, the quality of the bread is higher. In addition, the pairing process requires twice as much yeast and has the flexibility to better take into account the bakery properties of the flour. The list and ratio of individual raw materials used in the process of making a certain grade of bread is called a recipe.

Wheat bread preparation formula

Raw materials, kg (per 100 kg of raw materials):

Prime grade wheat flour 100

Water

Pressed yeast

Salts

Sahara

Zhirov

50 – 70

0,5 – 0,2,5

1,3 – 2,5

0 – 20

0 – 13

The recipe, which indicates the variety of flour and the amount of additional raw materials, except water, is approved by higher-level organizations (administration, ministry). In the recipes, the amount of main and additional raw materials is usually expressed in kg per 100 kg of flour.

Kneading and dough formation. Dough kneading is the most important technological operation, on which the further course of the technological process and the quality of bread largely depend. By kneading the dough from flour, water, yeast, salt and other components, a uniform mass with a certain structure and physical properties is obtained. Duration of kneading for wheat dough is 7 - 8 minutes.

Loosening and fermentation of dough. So that the baked product is porous and easily absorbed, the dough must be loosened before baking. This is a prerequisite for good test penetration. The dough begins to roam under the influence of carbon dioxide, which allows you to get bread with a well-loosened porous flesh. The purpose of fermenting the dough and dough is to bring the dough into a state in which it will be best prepared for cooking and baking in terms of gas-forming ability and structural and mechanical properties. At the same time, it is equally important to accumulate substances in the dough that determine the taste and aroma characteristic of bread from a well-fermented dough. The optimal fermentation temperature of the dough is 26-32 ° C.

During fermentation, the dough undergoes wrapping, that is, short-term repeated promess for 1.5-2 minutes. At the same time, carbon dioxide bubbles are evenly distributed throughout the dough mass, its quality is improved, the bread flesh acquires fine, thin-walled and uniform porosity.

Preparation of wheat dough by non-vapour method. The single-phase method consists in the fact that the dough is kneaded in one take out of the total amount of raw materials and water laid down according to the recipe, without adding any discarded semi-products (bumps, starters). The dough is prepared with a high yeast consumption (1.5-2.5% of the total flour weight). The increase in yeast consumption is explained by the fact that for their vital activity in the test worse conditions are created than in the opar (thick medium, the presence of salt, etc.). An increase in the dose of yeast is also necessary to loosen the dough in a relatively short time (2-3 hours). To reduce yeast consumption and improve the taste properties of the product, yeast is usually activated prior to kneading of the dough. The initial dough temperature is 29-31 ° C, the fermentation duration is 2.5-3 hours. After 50-60 minutes after kneading, it is recommended to wash the dough. Wrapping in the preparation of non-steamable dough has a greater technological value than for dough prepared on a dough. It should be noted that less acids, aromatics and flavors are present in the dough prepared in a non-volatile manner than in the dough prepared in an opar. Fermentation, colloidal and biochemical processes take place in a safe test less intensively due to the dough's thick consistency and reduced fermentation cycle.

By straight way dough is cooked in dough mixing cars with podkatny dezha (Standard car, T1XT2A) or by means of RZHTI car.

Dough cutting. In the production of wheat bread, dough processing includes the following operations: dividing dough into pieces; rounding; preliminary proofing; forming and final proofing of dough blanks.

Dividing the dough into pieces. Splitting the dough into pieces is done in dough-splitting machines. The purpose of the operation is to obtain a given mass of bread. To do this, dough separation machines operating on a volumetric principle are used. The dough of the piston is forced into a measuring pocket with a damper and pushed from there by another piston onto the conveyor or cut (stamped) into pieces of certain sizes. The permissible deviation of the mass of individual pieces shall not exceed ± 1.5%. The mass of a piece of dough should be 10-15% more than the mass of bread that has cooled, since during baking and cooling the mass of the product decreases.

Rounding up pieces of dough. After the tester, the dough enters the rounding machines, where it is given a round shape. The purpose of the operation is to improve the structure of the dough to obtain products with good porosity of the flesh.

Preliminary proofing. This is a process of tracing pieces of dough for 5-8 minutes, as a result of which internal stresses arising in the dough during fission and rounding are weakened and partially destroyed individual units of the gluten structural framework are restored. Preliminary proofing is carried out on belt conveyors or in pre-proofing cabinets, which are part of the flow lines. Fermentation at this stage does not play a significant role, so no special temperature conditions are created here.

Forming dough blanks. This is the process of shaping the dough pieces according to a given product class. To obtain dough pieces of wheat dough of a certain shape, they are rolled out by rolls into an elongated pancake, then rolled into a tube and rolled, and sometimes also extended. This additional treatment of wheat dough improves the porosity of the preforms. Formation of wheat dough is made by tape and drum zakatochny cars (HTZ1, T1-HT2-3-1, etc.).

Final proofing. The purpose of this process is to ferment the dough, which is necessary to replenish the carbon dioxide removed during the cutting stages. If you bake bread without final proofing, then it turns out to be small in volume, with a dense, poorly loose flesh, with breaks and cracks on the crust. Final proofing is carried out in an air atmosphere of a certain temperature (35-40 ° C) to accelerate fermentation and a certain relative air humidity (75-85%) to prevent curvature of the outer layers of the dough.

The duration of the proofing varies from 25 to 120 minutes depending on the weight of the dough pieces, the proofing conditions, the properties of the flour, the dough formulation and a number of other factors.

At most enterprises, dough blanks are proofed on wagons in special chambers for proofing.

Baking bread. Baking is the final stage of wheat bread preparation, which finally forms the quality of bread. In the baking process, microbiological, biochemical, physical and colloidal processes occur simultaneously inside the dough blank. All changes and processes that turn dough into finished bread occur as a result of heating of the dough stock. Bread products are baked in bakery chamber of bakery furnaces at temperature of steam-air medium 200-280 ° С. For baking 1 kg of bread, about 293-544 kJ is required. This heat is spent mainly on evaporating moisture from the dough preform and heating it to a temperature (96-97 ° C in the center), at which the dough turns into bread. A large proportion of heat (80-85%) is transmitted to the dough by radiation from the hot walls and arches of the baking chamber.

Dough blanks are warmed gradually starting from the surface, so all the processes characteristic of baking bread do not occur simultaneously in its entire mass, but layer by layer, first in the outer and then in the inner layers. The speed of heating dough, bread in general, and therefore the duration of baking depend on a number of factors. As the temperature in the baking chamber increases (within known limits), the heating of the preforms is accelerated and the baking time is reduced. Formation of hard bread crust occurs as a result of dewatering of outer layers of dough blank. The solid crust stops the increase in the volume of dough and bread, so the crust should not form immediately, but 6-8 minutes after the start of baking, when the maximum volume of the blank is already reached. In the surface layer of the blank and in the crust, biochemical processes occur: claysterization and dextrinization of starch, denaturation of proteins, formation of aromatic and dark colored substances and removal of moisture. In the first minutes of baking, as a result of condensation of steam, starch on the surface of the preform is claystered, passing partially into soluble starch and dextrins. The liquid mass of soluble starch and dextrins fills the pores on the surface of the blank, smoothes out fine irregularities and, after dewatering, gives the crust shine and gloss.

Denaturation (clotting) of protein substances on the surface of the product occurs at a temperature of 70-90 ° C. Coagulation of proteins along with dehydration of the upper layer contributes to the formation of a dense non-elastic crust.

The color of the crust depends on the content of sugar and amino acids in the dough, on the duration of baking and on the temperature in the baking chamber. For normal coloring of the crust in the dough (by the time of baking) there should be at least 2-3% sugar per weight of flour. Aromatics (mainly aldehydes) from the crust penetrate the flesh, improving the taste of the product. The moisture content of hot bread flesh (as a whole) increases compared to the moisture content of dough by 1.5-2.5% 3a due to moisture transferred from the upper layer of the blank.

During baking, fermentation microflora is suppressed inside the dough blank, the activity of enzymes changes, starch is claysterized and proteins are heat denatured, humidity and temperature of the inner layers of dough-bread change. The life of the fermentation microflora of dough (yeast cells and acid-forming bacteria) changes as a piece of dough bread warms up during baking. Yeast cells, when the test is heated to about 35 ° C, accelerate the fermentation and gasification process to a maximum. Up to about 40 C, the activity of the yeast in the baked piece of dough is still very intense. When the test is warmed up to more than 45 ° C, the gas formation caused by yeast is sharply reduced. At a dough temperature of about 50 ° C, the yeast dies.

The moisture content of the hot bread mill (as a whole) is increased in comparison with the moisture content of the dough due to moisture passed from the top layer of the blank. Due to lack of moisture, the claysterization of starch is slow and ends only when the central layer of bread dough is heated to a temperature of 96-98 ° C. The change in the state of protein substances begins at a temperature of 50-75 ° C and ends at a temperature of about 90 ° C. Protein substances undergo thermal denaturation (coagulation) during baking. At the same time, they are sealed and release moisture absorbed by them during dough formation. Folded proteins fix the porous structure of the flesh and the shape of the product. In the product, a protein frame is formed, into which grains of swollen starch are embedded. After thermal denaturation of proteins in the outer layers of the article, the volume increase of the workpiece stops.

The volume of the baked product is 10-30% more than the volume of the dough preform before landing it in the oven. The volume increase occurs mainly in the first minutes of baking as a result of residual alcohol fermentation, the transition of alcohol to a vapor state at a temperature of 79 ° C, as well as the thermal expansion of vapors and gases in the dough blank. Increasing the volume of dough bread improves the appearance, porosity and digestibility of the product.

The toric determination of product readiness is important. If the product is unsaved, it has many defects, and an excessive increase in baking time increases the baking, reduces the productivity of the oven, and causes fuel overspending. An objective indicator of the readiness of the product is the temperature in the center of the ball, which at the end of baking should be 95-97 ° C. However, readiness is determined organoleptically by the following indicators: the color of the crust is light brown or brown; the condition of the kebum - the ball of the finished product is relatively dry and elastic; relative weight - weight of baked article is less than weight of unprepared article.

A package is a reduction in the weight of the dough preform during baking, that is, the difference between the mass of the dough and the mass of the hot product. The package is expressed in% to the weight of the dough before it is put in the oven. The main reason for the fall is the evaporation of moisture during crust formation.

Currently, the most widely used dead-end lulinoid furnaces with channel heating. The temperature in the baking chamber is controlled by varying the combustion intensity of the fuel.

Determination of bread readiness. The correct determination of bread readiness during the baking process is of great importance. Its quality depends on the correctness of determining the readiness of bread: the thickness and color of the crust and the physical properties of the flesh - elasticity and dryness to the touch. Excessive baking time increases baking, reduces productivity, and causes fuel overspending. An objective indicator of bread readiness is the temperature in the center of the ball, which at the end of baking should be 96-97 ° C.

In production, the readiness of products is still determined organoleptically by the following signs: the color of the crust (the color should be light brown); the condition of the kebum (the ball of the finished bread should be relatively dry and elastic). Determining the condition of the ball, hot bread is broken (avoiding shaking) and slightly pressed with fingers on the ball in the central part. The condition of the flesh is the main sign of bread readiness; relative weight (the weight of the baked article is less than the weight of the unprepared article, due to the difference in bulk). The readiness of the bread can also be determined by the temperature in the center of the ball at the time the bread leaves the oven using a thermometer. To avoid breakage of the thermometer when inserted into bread, it is recommended to make a puncture in the crust with some sharp object, the diameter of which would not exceed the diameter of the thermometer.

The length of the end of the thermometer introduced into the bread should be set in advance. The point of introduction of the thermometer into bread is specified at each determination. To measure the bread temperature, the thermometer must be preheated to a temperature of 5-7 ° C below the expected bread temperature (heating can be carried out in another loaf of bread). This is done to prevent cooling of the ball and to overcome the inertia of the meter. It is necessary that the mercury rise in the thermometer takes place for not more than 1 minute. Before checking the baked bread at its temperature, it is necessary to experimentally set the temperature of the bread flesh corresponding to the baked bread at this enterprise. Usually, the temperature of the center of the flesh, which characterizes the readiness of rye shaped bread, should be about 96 ° C, wheat - about 97 ° C. The temperature of bread, which characterizes its readiness, established experimentally, can be used to control the readiness of bread and the size of the package [1, 2].

1.3 Storage and Transportation

Baked bread during storage cools and loses in mass due to drying and blackening. These two processes are independent, but they are somewhat dependent on each other, since the bread mill, which has lost a certain amount of moisture, partially loses its softness not only due to the blackening process, but also due to a decrease in humidity.

Stacking of finished products after it leaves the oven and storage of products before their release into the retail network are the last stage of the bread production process and are carried out in the bakeries of enterprises. The capacity of bakeries is usually calculated taking into account the storage of replacement production, and when working in 2 shifts - taking into account one and a half shift work.

The bakery accounts for the produced products, its sorting and organoleptic assessment according to the point system. Before the products are released to the retail network, each batch of products is subject to mandatory viewing by a bracker or a person authorized by the administration. Marriage as a means of fighting for the vacation of good quality products to the retail network is mandatory for all bakery enterprises producing bread, bakery, lamb and dry products.

Rules for laying, storage and transportation of bread products are defined in GOST 822756.

After baking, the products are placed in wooden trays, the dimensions of which are determined by GOST 1135482 "Boards and plywood multi-turn boxes for food products."

Moulded bread is laid on the side or lower side, hearth bread, buns, batons - in 1 row on the lower side or rib, such products - in 1 row flames. Trays with bread (14-28 pcs) are placed on mobile cars, which are taken to the loading platform as necessary.

Bread is stored at the enterprise for 14 hours, and must be sold within 36 hours from the moment it leaves the oven. Acceptance rules. Batch definition and acceptance rules - as per GOST 566765. Each batch of products must be accompanied by a document of the established form certifying its quality.

Conclusion

As a result of the course project, the designs of test kneading machines were reviewed, a patent search was carried out. Various schematic diagrams of dough kneading machines are considered.

According to the given initial data, technological, energy, kinematic and structural calculations were carried out.

A separate section deals with safety requirements during installation, adjustment and maintenance.

During the course project, he expanded and consolidated knowledge of technological equipment for processing and storage of agricultural products, acquired skills in independent work with graphic and text materials and special technical literature.

The graphic part contains: a hardware and technology diagram of wheat bread production, a drawing of a general view of the dough kneading machine Prima300R, as well as a detail of the kneading organ.