BG112904A - Asphalt and concrete mixtures production equipment of an asphalt mixer machine - Google Patents

Abstract

The asphalt and concrete mixer production equipment of an asphalt mixer machine finds application in road construction. The equipment will be implemented mechanically and operationally in the existing asphalt mixer machine: - the old asphalt mixture from a receiving hopper (17) is transported via a feed belt (19) to to the lifting elevator (21), through which it reaches the drying drum (18), whereby it is heated to 150-170оС and by means of a metering auger (20) is fed to the stirrer (4), where it is mixed with the newly produced asphalt mixture - fig. 1; - the inert materials from the feed hoppers (1) are transported to the stirrer (24) through the feed belt / metering device (22), and at the same time the cement is added through the silo with the metering device (23). The metered water is fed directly into the stirrer (24). The mixture is homogenized for 50-60 s - fig. 1. The equipment will assist in saving bitumen, fractions, human resources, fuels, and will lead to environmental protection and efficiency thereto. The disposal of "milled asphalt" will be limited to a maximum extent.

Description

DESCRIPTION

Name: Plant for the production of asphalt and concrete mixtures for an asphalt mixer

Field of technology: Construction of roads, streets and road surfaces - asphalt laying. Production of asphalt and concrete mixtures.

BACKGROUND OF THE INVENTION: Currently, old asphalt pavements are discarded or used as perishable pavements for car parks and unloaded streets.

Attempts have been made to add used (old) asphalt mixture to the new mixture, but it can only be added by bypassing the drying drum and in the cold state, hoping that it will be heated by the heated aggregates (IM). In this way, however, the use of the old asphalt shredder cannot exceed 20%, because the inert materials cannot be heated to more than 180-200 ⁰ C, as they are mainly made of limestone and there is a change in their chemical composition. A very small part of them are recycled and their use reaches 20%. The old mixture is usually compromised and therefore it is tested in the laboratory and serves as an additive to the new asphalt mixture.

Almost all road construction companies, in addition to asphalt bases, also have concrete units. The idea in the production of concrete mixtures is to combine the common parts, ie both the concrete unit and the asphalt base have bunkers for IM as well as operators who are not loaded 100% of the time.

Similar developments of equipment for the production of asphalt mixtures from old asphalt mixture "milled asphalt" in Western Europe (Finland) are known, which proved to be financially unaffordable for the Bulgarian market. The main source of information for the current development of "Plant for the production of asphalt and concrete mixtures to the asphalt mixer" are:

BDS EN 13242 - Rock materials for unbound and hydraulically bound mixtures for use in construction equipment and road construction - for the production of asphalt;

BDS EN 12620 - Admixtures for concrete - for concrete production.

Technical essence: The asphalt mixture is a homogeneous mixture, which is obtained by mixing inert materials (stone fractions) with selected grain sizes and binder bitumen.

The binder - bitumen has a hard consistency and therefore the technological process of homogenization is carried out at a temperature of 170-180 degrees.

Asphalt mixtures are produced in asphalt bases. The machine for the production of asphalt mixture is called Asphalt Mixer.

The technological process for the production is the following:

Cold (rough) dosing hoppers are loaded with a front loader with the necessary stone fractions with selected grain sizes.

1. Combining the hoppers for aggregates (IM) for the production of asphalt and concrete mixtures. The grain size of IM for the production of concrete and asphalt mixtures is the same. Usually asphalt mixers are not 100% loaded and therefore in order to save human resources it is possible to use cold hoppers for the production of concrete mixtures, ie with one and 2 mixes with the newly produced mixture. Thus, the percentage of use of the old mixture "milled asphalt" will be in the range of 50-70%.

Preheating the old mixture, which is the purpose of the model, saves bitumen, IM (fractions), human resources, fuels, and avoids pollution because it recycles waste material. Efficiency in value terms can easily reach 30%

The idea in the production of concrete mixtures is to combine the common parts, ie both the concrete unit and the asphalt base have bunkers for IM as well as operators that are not loaded 100% of their time, in addition, when computerizing the process can be done savings from mechanized and human resources.

Description of the attached figures: Appendix 1 is a diagram of an asphalt mixer and a new facility.

The existing asphalt mixer - The feed hoppers 1 for cold (rough) dosing are loaded with a front loader with the necessary stone fractions (aggregates) with selected grain sizes. The conveyor belt 16 transports them to a drying drum 2, where they are heated to the set temperature with a gas burner. Air duct ^ 5 leads the exhaust gases to the bag filter 3, which serves for dedusting of the inert materials and subsequent dosing of the own dust in the asphalt mixture. From the drying drum 2, the fractions are transferred to the so-called "warm" sieves / mixer 4, where the precise weight dosing is performed. The dosed fractions are fed to the mixer 4, where the bitumen heated to 170 -180 degrees is also dosed according to the recipe. After the necessary technological time for complete homogenization, the finished asphalt mixture is transported by rail 7 in a hopper for ready mixture 5, from where it is poured into the vehicles and sent to the site for laying. From 4 unbound and hydraulically connected mixtures for use in construction facilities and road construction) - for asphalt production and BDS EN 12620 (Additional materials) - for concrete production, laboratory tests, developments and tests were performed in an accredited laboratory for asphalt production a mixture with added in the range of 50-70% "milled asphalt" preheated to 150 -170 ⁰ C. The resulting asphalt mixture as a result of the experiment meets all the requirements for performance and quality standards and does not differ from asphalt mixtures, produced only with the use of new materials.

The application of the product from the technique "Equipment for production of asphalt and concrete mixtures to asphalt mixer" will be used effectively in the construction of roads, streets and pavements. The use of "milled asphalt" in the amount of 50-70%, leads to the economy of bitumen, fractions, human resources, fuels, environmental protection and efficiency. The disposal of "milled asphalt" in road repair works will be limited as much as possible, after milling.

Application:

Diagram of Asphalt mixer and the new facility-fig.1 Indications existing and new facility

Claims (4)

Equipment for production of asphalt and concrete mixtures for asphalt mixer. Claim 1 - Plant for the production of asphalt and concrete mixtures to an asphalt mixer, characterized in that it comprises a receiving hopper (17) connected by the supply belt (19) to the lifting elevator (21) connected to a drying drum for old asphalt ), which is connected by a dosing screw (20) to the mixer (4) of the existing asphalt mixer, and all devices are connected to the command point (6) of the existing asphalt mixer - Fig.1 Claim 2 - Plant for the production of asphalt and concrete mixtures to an asphalt mixer, characterized in that it comprises the feed hoppers (1) of the existing asphalt mixer connected by the feed belt (dosing device) (22) to a silo with a dosing device (23) and with mixer (24), and all devices are connected to the command point (6) of the existing asphalt mixer - Fig.1 Claim 3 - Technological process for the use of old milled asphalt mixture. The technological process is characterized by heating of an old cold sifted (milled) asphalt mixture, which with a front loader is fed into the receiving hopper (17) 'and through the supply belt (19) is transported to the lifting elevator (21) and through it to the drying a drum (18), in which it is heated to 150 -170 ⁰ C with a gas burner and dosed by weight, is fed through a dosing screw (20) to a mixer (4), where it is mixed with the newly produced asphalt mixture until homogenization is reached. 9 Claim 4 - Technological process for concrete production The technological process is characterized by the use of the feed hoppers (1) for cold (rough) dosing, which are loaded with a front loader with the necessary stone fractions (aggregates) with selected grain sizes and through the feed strip (22), which is also dosing device, are transported to the mixer (24), at the same time the necessary water is added, and through a silo with dosing device (23) the cement is added, where the ready concrete mixture is homogenized after the necessary technological time (about 50-60 s ).