SU1257010A1 - Internal combustion engine lorry body for haulage of muck - Google Patents

Description

The invention relates to a transport engineering, namely vehicles for transporting rock mass, and can be used in the mining industry in transporting ore, rock, etc. from open pit and underground mine workings.

The aim of the invention is to increase the efficiency of cleaning exhaust gases from harmful substances and reducing pollution of the atmosphere around them by ensuring self-regulation of the height of the filtering layer of the rock mass and preventing clogging of the outlet openings.

The drawing shows a loaded dump truck body, general view with a local section.

A truck body for transporting the rock mass of a vehicle with an internal combustion engine contains cavities 1 formed in the walls of the body, connected to the exhaust gas system of the internal combustion engine (the “exhaust system from two”) and connected to the atmosphere through internal ventilation. the body walls are the outlet openings 2. The latter are placed in the middle height of the walls of the body part and are provided with guide pipes 3 inclined in the direction of the body depth. For example, in a loaded body exhibiting tubes are within Nabal transported rock mass 4.

The exhaust gases from the exhaust system of the internal combustion engine flow into cavities 1, and then through the outlet openings 2 and guide tubes 3 into the bulk of the transported rock mass 4. When transporting lumpy rock mass with a small amount of small particles, the exhaust gases penetrate into the most the deepest part of the body, which, together with the dynamic pressure of the gas flow at the inlet and the bulk of the transported rock mass, is provided by the tip of a guide pipe in the direction of the deepest part and body. After penetration into the bulk of the rock mass, the exhaust gases lose dynamic pressure and under the action of static pressure, in some cases also due to high temperature and lower density relative to the surrounding air, are filtered through the rock space of the rock mass and out into the atmosphere (direction exhaust gas movements are indicated by arrows).

Purification of exhaust gases from harmful substances occurs during the movement of gases in the inter-arcuate space of the rock mass 4 due to adhesion, adsorption and chemical interaction.

The obstruction of the outlet openings 2 is eliminated due to the inclination of the guides

nozzles 3 and placement of the outlet openings in the mid-height walls of the body part, where no accumulations of small particles of rock mass, characteristic of the deepest part of the body, are formed.

The depth of penetration of the exhaust gases into the bulk of the transported rock mass and the height of the filtering layer depend on the amount of fine particles in the transported rock mass. The total surface of the pieces in the pile and their average size are, as is well known, depending close to right proportional.

The aerodynamic resistance of a static layer material can be found by the formulas

... x 4

Xl 4e

d.

20

J, S6

) "

0

n d-V-d gttgdeR aerodynamic resistance; 5 V-flow rate of exhaust gases in the bulk of the rock mass (determined by the nominal flow of exhaust gases of the dump truck BelAZ-548 with an average temperature of 400 K per section (0.3x0.6) -2 m);

0 j - exhaust gas density with a temperature of 400 K (corresponds to the density of air with the same temperature, the table value); f-porosity of the bulk of the transported rock mass (taken according to Glinko-5V MA, equal to 0.45);

h-depth of penetration of exhaust gases to the bulk of the transported rock mass or the height of the filtering layer; ds is the equivalent diameter (determined by the size of the pieces (particles) of the transported rock mass); , is the kinematic viscosity of the exhaust gases at a temperature of 400 K (is received through the air of the corresponding temperature, table value).

To determine h, it is necessary to have the value of the dynamic head of the gas flow at the entrance to the bulk of the transported mountain mass, which, as is known, is defined by the expression

H

5iiYl

2:

whereLnD dynamic pressure,

 - Density of exhaust gases at the entrance to the bulk of the transported rock mass (received by air with a temperature of 5600 K);

Yi-cKopocTb of the gas flow at the inlet to the bulk of the transported rock mass (adopted for the consumption of

gases at the nominal mode of operation of the BelAZ-548 dump truck engine equal to 0.5 M Vc, corrected for temperature 800K-1.45, for the total cross-sectional area of the guide nozzles 2 (0, lxO, 4m) is 18 m / s );

For the accepted values of S and V, the value of Nd will be 80 Pa.

Solving together the equations for aerodynamic drag and dynamic head relative to h, we find that the dynamic head value 80 Pa corresponds to the value of the depth of penetration of exhaust gases into the pile of transported rock mass; for an average piece with a fin size of 0.2m - 0.94 m; for an average piece with a fin size of 0.1 m-0.43 m.

For the BelAZ-548 dump truck, the penetration depth, equal to 0.94 m, corresponds to the distance from the average height of the walls of the body part to the bottom of its deepest part.

At the maximum depth of the body of the BelAZ-548 dump truck, approximately 2 m, reducing the size of the average piece of transported rock mass from 0.2 to 0.1 m reduces the height of the filter bed from 2 to 1.4 m.

Accepting a filtration area of 3 m, and the temperature of the exhaust gases is close to 300 K, i.e. at an exhaust flow rate of 0.5, we find that the aerodynamic resistance of filtration is 2.4 Pa for a layer 2 m high, consisting of pieces with an average size of 0.2 m, 3.3 Pa for a layer 1.4 m high, of pieces with an average size of 0.1 m and 5.1 Pa for a layer 2 m high, consisting of pieces with an average size of 0.1 m (prototype).

Thus, with a decrease in the size of the middle piece by 2 times, the height of the filtering layer decreases 1.4 times, the total surface of the pieces in the filtering layer increases 1.4 times, the aerodynamic drag decreases 1.6 times. When filling the interstitial space with small particles with an average size of, for example, 0.01 m, the depth of penetration into the pile of transported rock mass is 0.03 m; height of the filtering layer 1.1 m; an increase in the surface of the particles in the filtering layer (as compared with the layer consisting of pieces with an average size of 0.2 m) by 2.7 times; aerodynamic resistance of the filter layer 1.1 m high (for the proposed technical solution) 38 Pa, for a layer 2 m high (prototype) 69 Pa.

The invention provides, in comparison with the prototype, a decrease in the aerodynamic resistance of filtration by 1.8 times.

The results of calculations show that with an average size of pieces of transported rock mass of 0.2 m, the height of the filter layer becomes maximum (equal to the height of the prototype filter layer) and does not change with a further increase in the size of the pieces. At the same time, the maximum possible efficiency for a given and a larger average size of pieces of transported rock mass is provided.

0 exhaust gas purification.

With an average particle size of 0.01 m, the height of the filter layer becomes minimal and does not change with a further decrease in particle size. Thus, with

5, reducing the height of the filter bed to the minimum area of contact of the exhaust gases with the transported rock mass is not reduced. Consequently; The exhaust gas cleaning efficiency does not decrease.

0 Similarly, the necessary dependence of the depth of penetration of exhaust gases into the bulk of the transported mountain mass in the cargo body of the vehicle with parameters different from

 parameters of dump truck BelAZ-548.

From the results of the calculation, it also follows that the smallest aerodynamic drag increases are caused by small particles filling the inter-arcuate space. In addition, small particles under the action of vibration during the movement of a dump truck fall between large pieces in the deepest part of the body, where they form tight aggregations at the points of junction, grooves, blind holes.

5 Since, in the prototype, the outlets are located in the zone of the deepest part of the body, clogging and blockage by such accumulations are unavoidable.

The share of rock mass with a large number of small particles is at least 40% of the total amount of rock mass transported by quarry vehicles.

As indirect experience shows (filling of grooves, etc. in the cargo body with compact accumulations of small particles), the clogging of the outlet openings located in the zone of the deepest part of the body occurs after 8-10 runs of a dump truck with a total number of flights during shifts 15-20. Cleaning the outlet openings without reducing the performance of the dump truck is really only possible in the between-shift period.

As a result, due to the uncontrollability of the height of the filtering layer and the location of the outlet openings in the zone of the deepest

5 parts of the body, leading to an unacceptable increase in aerodynamic drag, near the total average exhaust gas flow rate in the prototype

0

enters the atmosphere without cleaning.

In this invention, due to the self-regulation of the height of the filtering layer from the maximum value (corresponding to the prototype) to sufficient to ensure effective contact area of the exhaust gases with the rock mass, which is provided by placing the outlet openings in the middle height of the walls of the body part and guides inclined towards the deepest part of the body. nozzles, an increase in aerodynamic drag over the permissible limit due to the filling of the interstitial space with small parts They are significantly reduced (an approximately two-fold reduction in the aerodynamic resistance of the filtering layer is achieved. Clogging of the outlet openings is practically disconnected by placing them in the middle height of the body wall and inclined guide nozzles. Thus, almost all of the exhaust gases rock clay) is filtered through rock mass).

In the proposed technical solution, the exhaust gas cleaning efficiency is further enhanced by the deposition of aerosols, including soot, when the downward direction of gas movement changes to upward, associated with a decrease in the gas flow rate and provided by placing the outlet openings in the middle height walls of the body part and inclined in the direction of the deepest part of the body by guide pipes.

The protruding parts of the nozzles that extend beyond the inner surface of the body practically do not reduce the useful volume of the body. For example, for

the body of the dump truck BelAZ-548 with a volume of 15 m; the total volume of protruding parts of the guide pipes does not exceed 0.05 m or 0.03% of the volume of the body. The increase in the metal content of the body is also not significant (not more than by 0.01%). The location of the guide nozzles in the middle height of the body part walls at a considerable distance from the body bottom (for example, for the BelAZ-548 dump truck to 0.9 m) excludes their delay in the part of the rock mass when unloading the body, and the insignificant dimensions over the nozzle cross-section exclude the formation voids under it when loading. Thus, for a dump truck, the BelAZ-548 with a body size along a width of 3.7 m, a length of 5 m and a height of 2 m, the sizes of the protruding parts of each of the two guide nozzles are in the width direction of the body 0.4 m, length 0.1 m, heights of 0.25 m. Consequently, the nozzles do not adversely affect the performance of the cargo body. In the design of this cargo body, an emergency exit for exhaust gases should be provided in case of transportation of viscous rock mass such as clay, etc. It is advisable to connect the emergency exit with the atmosphere through a porous nozzle with an aerodynamic resistance much higher than the aerodynamic resistance of the bulk of the lumpy rock mass transported, but not exceeding the allowable value. As a porous packing, catalytically active materials, such as mesh capsules with granular catalyst, placed in the cavity of the body walls before the emergency exit can be used. The cargo body does not exclude the use of any other known means and methods of gas cleaning in combination with it.

Claims (1)

FREIGHT BODY FOR TRANSPORTATION OF MINING MASS TRANSPORT- FUNCTIONS WITH INTERNAL COMBUSTION ENGINE, containing cavities made in the walls of the body, connected to the exhaust system of the internal combustion engine and connected to the atmosphere through exhaust openings made on the internal surfaces of the body walls, characterized in that, in order to increase the efficiency of cleaning the exhaust gases from harmful substances and reduce pollution of the surrounding atmosphere by ensuring self-regulation of the height of the filter layer of the rock mass and preventing clogging yhodnyh openings, said outlet openings are provided with guide nozzles mounted obliquely in the direction of depth of the body.