Modernization of flour screening machine MPM-800

Contents

Introduction

1 Purpose and application of flour screening machine

2 Description of design and operating principle of flour sieve

3 Technical characteristics

4 Design and calculation of flour sieve drive

4.1. Development of the drive design

4.2. Kinematic calculation of the drive

4.3. Calculation of drive elements

5 Design development and screw calculation

5.1. Screw calculation

5.2. Screw Strength Calculations

5.3. Screw fabrication

6 Occupational and environmental protection

Conclusion

List of literature used

Introduction

Flour, sugar, cereals and other loose products are supplied to food enterprises in various containers - bags, cardboard boxes, etc., which leads to their clogging with mechanical impurities .

Before directly using flour, even the highest grade, you need to take care to improve its quality. The flour may contain metal impurities and other foreign particles; in addition, falling into bags during packing and long being in them, the flour is strongly compressed and ceases to be sufficiently saturated with oxygen. This greatly affects the quality of the final product, since undesirable impurities are very harmful and significantly degrade the quality of bakery products, and the loss of such an important property of flour as oxygen saturation leads to the product eventually becoming not sufficiently soft and lush.

It is known that the taste, color and nutritional value of bakery and confectionery products depends on the quality of flour. There are several varieties of flour: wheat, rye, corn, barley, etc. In order for the flour to be used in the preparation, it must be processed, because at first it contains various impurities that should not get into the product. In order for bakery products to have impeccable quality and taste, many bakeries use flour seeders. Today, manufacturers offer various types of productivity and sifting machines: vibration and centrifugal. The principle of operation of the vibration type flour sieve is the vibration of the screen, through which flour is passed in portions. The principle of operation of the centrifugal type flour sifter with screw feed is that the flour is filled into the hopper, fed to the screen with a screw screw and sieved. Due to this, ventilation, removal of moisture and screening of flour, as well as its mixing, loosening and saturation with oxygen, occurs. Metal particles are removed by means of a magnetic system of metal collectors. Modern flour sifters are very simple and reliable to use. They are made of stainless metal and silk fibers, easily move by wheels and therefore can be placed anywhere in the production room.

Flour sifter is designed not only to improve the quality of flour, but also to accelerate the cooking process, as it can work continuously and process large volumes of flour.

Flour screening machines are an integral part of equipment in catering places, bakery and confectionery enterprises. Its main purpose: sifting, loosening and aeration of flour. The machine, equipped with the necessary brushes, sieves, magnets, saves the flour from harmful impurities, saturates it with oxygen, thereby improving the quality of the product.

In this course project, the MPM800 flour screening machine will be modernized in order to increase its productivity.

Purpose and application of flour screening machine

Sievers are used to mechanize the process of separating foreign impurities (mechanical and organic) from bulk products in confectionery, flour and hot shops, as well as in specialized enterprises - pancake, dumpling, jam, pie, etc. Flour is sieved both for separation of mechanical impurities, and for loosening and saturation of it with air, which ensure normal life activity of yeast during dough fermentation. Dough kneaded from such flour gives a larger solder, and the finished products are more magnificent.

As a result of sieving, the product is divided into two fractions: a passage with particle sizes less than the holes of the sieve (passes through them) and a non-sieve or discharge - with particle sizes more than the holes of the sieve (remains on the surface of the sieve).

The working tools of the sievers are screens of various designs, made, most often, of metal grids. Depending on the screen design, sieves are divided into two groups:

with cylindrical screens (fixed and rotating);

with flat vibration sieves.

With fixed sieves, sieves have special drivers.

For high-grade flour, sieves with cells measuring 1.4 mm are used, the first - 1.6 mm.

There are two types of flour sifters:

vibration

Vibration-type flour sifters are designed for sifting flour and cleaning from foreign impurities using magnetic traps, and also serve for loosening and aeration of flour (oxygen saturation), which contributes to better fermentation of dough. Flour sowing agent can be used in catering, bakery and confectionery industries. The principle of operation of the vibration type flour sieve is the vibration of the screen, through which flour is passed in portions.

centrifugal with screw feed

The principle of operation of the centrifugal type flour sifter with screw feed is that the flour is filled into the hopper, fed to the screen with a screw screw and sieved. Due to this, ventilation, removal of moisture and screening of flour, as well as its mixing, loosening and saturation with oxygen, occurs.

To remove metal particles from flour, a metal trapping system is used, consisting of a set of magnetic arcs with a cross section of a strip of 48 x 12 mm. The maximum carrying capacity of magnets is 12 kg, the minimum - 8 kg. Once every 1015 days, these indicators are checked, and arcs are magnetized when load capacity decreases.

When choosing a specific sifter model, it should be borne in mind that most of them have high productivity, which is in demand only at factories-procurement and bakery enterprises (over 300 kg/h). So, the PVG600M vibration sieve and the PM900M4 centrifugal (with a cylindrical rotating sieve), manufactured by Voskhod (Russia), allow you to sift 600 and 900 kg/h respectively (by flour).

Sifters MPM800 and MS24300 to universal drive PG0.6 and small-sized sifter MPMB300 were widely used at catering enterprises.

At food and catering enterprises, other machines are used in confectionery shops. They are similar, but the difference is that due to modernization, the productivity of products is increased, economic indicators are improved, and the duration and reliability of the machine are increased.

In the bakery industry, various sieves with a horizontal sieve are used to sift both flour and sugar sand.

Conclusion

The improvement of equipment should ensure not only the growth of labor productivity and its facilitation, but also the reduction of labor costs per unit of production when using new machines and mechanisms. In other words, new equipment will only be effective if the cost of public labor for its creation and use requires less labor saved by the use of this new equipment. In the end, the economic essence of improving machines and mechanisms lies in reducing the cost per unit produced using new equipment.