Calculation and design of scraper conveyor - DBE, Drawings

Contents

Introduction

1 Calculation and design of scraper conveyor

1.1 Kinematic diagram of scraper conveyor

1.2 General Arrangement and Basic Parameters of the Scraper Conveyor

1.3 Calculation of scraper conveyor

2 Circuit selection

3 Determination of scraper dimensions

4 Calculation of conveyor elements

4.1 Calculation of drive sprocket

4.2 Tensioner calculation

4.3 Circuit Tension Diagram

5 Engine selection

6 Gearbox selection

7 Installation and safety of scraper conveyors

8 Operation and Safety Rules for Scraper Conveyors

Conclusion

Literature

SUMMARY

The course project in the discipline "Continuous transport machines" on the topic "Calculation and design of the scraper conveyor" contains:

- sheets of graphic part 3

- sheets of design - explanatory note 32

- Figures 7

- Table 1

Keywords:

scraper conveyor, plate chain, drive sprocket, tension sprocket, scrapers, tensioner, reduction gear box, electric motor, bearings, rupture force.

Introduction

Continuous transport machines have found their use in many industries, in particular in heavy, light and food industries.

Continuous transport machines are characterized by continuous movement of bulk or piece loads along a given route non-stop for loading or unloading. Movable bulk weight is arranged in continuous layer on bearing element of machine-belt or web. The unit weights also flow continuously in a predetermined sequence one after the other. Due to the continuous movement of goods, the lack of stops for loading and unloading, these machines have high productivity.

Scraper conveyors include various conveying machines in which the load is moved by means of moving scrapers by drawing along a trough or pipe of rectangular or round section. The shape and height of the scraper are the main features by which scraper conveyors are divided into

design types Distinguish between conveyors with solid and contour (shaped) scrapers. Solid scrapers are high and low; the height of the high scrapers is approximately equal to the height of the trough and several times the height of the traction chain; the height of the low scrapers is close to the height of the chain and is significantly (3-6 times) less than the height of the trough. Conveyors with high and low solid scrapers differ significantly from each other in terms of design characteristics. A separate design variety is tubular scraper conveyors with round (or rectangular) solid scrapers. Their distinctive feature is the wide versatility of the configuration of the cargo transportation route .

Contour scrapers are classified according to their shape, which determines. different design parameters of conveyors. [2].

By the nature of the movement, scraper conveyors with continuous translational and reciprocal movement of scrapers are distinguished.

Reciprocating motion is characteristic of rod scraper conveyors with continuous high scrapers hinged on a rigid rod (they are called scraper and are used to transport hot ground in foundry shops) and with special rigidly fixed scrapers - spikes. The latter are used for twisted transportation. metal chips. Cable conveyors for transporting firewood, wooden balances and the like in open chutes are known. Low-capacity conveyors (up to 5 m3/h) belonging to the group of scrapers without scrapers are also used; the dragging of the load in them occurs due to the adhesion of its particles to a chain (usually round-link) moving in the pipe. It is known to combine a suspended load-carrying conveyor with a scraper conveyor, in which above the trough

Scraper conveyors were widely used in coal mines, concentration plants, chemical and food industries. Conveyors with low scrapers in a variety of design modifications are currently the main units for underground coal transportation in mines.

The advantages of scraper conveyors are the simplicity of the design of the intermediate unloading device (everywhere, except for vertical sections of the route); possibility of tight transportation of spotting, gasifying and hot cargoes. Disadvantages include intense wear and tear

the undercarriage and trough, especially when moving abrasive loads, since the scrapers and in most cases the traction chain rub against the trough in the cargo environment; significant energy consumption due to friction of the load and undercarriage

trough; crumbling and grinding of cargo during transportation by drawing, which for some goods (for example, for coke) is unacceptable, and for many. undesirable [2].

1.2 General Arrangement and Basic Parameters of the Scraper Conveyor

Scraper conveyor with solid high scrapers (Figure 2) consists of open chute 5 fixed on bed 4, along which vertically closed traction chain (or two chains) 1 with scrapers 2 fixed on it moves, enveloping end (drive and tension) sprockets. Motion of traction chain is obtained from drive 3, and initial tension - from tensioner 6. The transported load is filled into the conveyor chute anywhere along its length and pushed by the scraper along the chute. The conveyor can be unloaded anywhere along its length through openings in the bottom of the trough covered by gate valves or gates. The latter are opened by means of electromechanical (screw), pneumatic or hydraulic drive with manual or remote control. For small conveyors, manual drives are sometimes used.

The load can be transported along the lower branch, the upper branch (with cantilever scrapers) or simultaneously along the upper and lower branches in different directions (with symmetrical scrapers).

Scraper conveyors with high scrapers in the main versions are vertically closed and move the load in horizontal, inclined, inclined-horizontal and horizontal-inclined directions. Combined routes are possible only for conveyors with two traction chains or with one chain equipped with support rollers for guiding the undercarriage in a rotating section.

The angle of inclination of scraper conveyors usually does not exceed 30-40, since with its increase the productivity of the conveyor decreases significantly. With the use of special, so-called box, scrapers with movable side walls, the inclination angle of the conveyor increases to 500. in conveyors of this type, the inner links of the traction chains are made of sheets of the same height with a scraper. Such a design forms a sequential set of moving open boxes without a bottom; fixed chute of conveyor serves as bottom.

Conclusion

In this course work, a preliminary calculation of the scraper conveyor was made. As a result of these calculations, the following values ​ ​ were determined:

- width of scrapers, mm........................................................................................ 356 ;

- height of scrapers, mm......................................................................................... 156;

- effort on the running branch, kN................................................................1.798;

- effort on the running branch, kN............................................................12.259.

An asynchronous short-circuited three-phase electric motor of the brand was also chosen: 4AM100S4Y3 with a power of 3 kW; and the drive elements are selected: gearbox of the 1Ts2U - 250 series and plate traction chain M 160 - 1 - 100 - 1 GOST 588 - 81.

A drive asterisk was calculated with the following results:

- number of teeth..................................................................................................... 6;

- step of teeths....................................................................................................200;

- dividing diameter, mm................................................................................. 400;

- diameter of an external circle, mm......................................................446.72;

- angle of teeth recesses, deg.............................................................................. 86.

The calculation of the tensioner led to the following results:

- type of device.......................................................................... screw;

- number of screw nut turns................................................................................. 3;

- device tension force, kN.................................................................. 26,235;

- stroke, mm.................................................................................................... 320;

- internal diameter of the screw, mm..................................................................50;

- diameter of tops of rounds, mm.......................................................................57;

- angle of thread lifting, deg.......................................................................... 3.19.

In this way, a scraper conveyor with high scrapers has been designed to transport the earth forming with the required capacity, this conveyor can also be used to transport materials such as gravel, ground stone, slag and others.