JPH01214606A - Manufacture of asphalt composite material and ready-mix concrete, and device therefor - Google Patents

Abstract

PURPOSE:To enhance economical efficiency by mixing aggregate with asphalt under injection in manufacture of asphalt composite material and kneading the aggregate with cement and water in production of ready-mix concrete with use of the same device. CONSTITUTION:Below a cold hopper 6 situated on the lower end of an aggregate heating/mixing drum 3 having an asphalt injection nozzle 24 inserted thereinto, there are arranged an aggregate weighting bath, cement weighting bath and water weighting bath. A blower 7 and an air exhausting flue 12 are connected with the cold hopper 6 and the drum 3 respectively. In manufacture of asphalt composite material, the aggregate and stone powder at a predetermined quantity are heated in the drum 3 and the asphalt is mixed through injection. Further, in manufacture of ready-mix concrete, the aggregate at a predetermined quantity is dried in the drum 3 and thereafter is put into the mixer 31 together with cement and water so as to be kneaded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an apparatus for producing asphalt mixture and ready-mixed concrete, which are road paving materials.

[Prior art] Conventionally, asphalt mix was produced in an asphalt plant, and ready-mixed concrete was produced in a batcher plant.
Each had its own dedicated plant. Asphalt mixture is exclusively used as a road paving material, but this is because concrete pavement has various drawbacks such as a long curing period. In recent years, compacted concrete pavement has been developed to overcome the drawbacks of concrete pavement.This compacted concrete pavement consists of leveling cement concrete with zero slump on the road and leveling it with vibrating rollers. This is a paving method that can significantly shorten the curing period, enable early opening, and has the advantage that a paving machine for asphalt mixture can be used as is.

[Problems to be solved by the invention] However, asphalt concrete and asphalt concrete are used for road paving.
If you want to use both cement and concrete, you will need to have both an asphalt plant and a batcher plant, but owning both plants is a heavy economic burden. We believe that it is desirable to construct a single plant with the following features.

Therefore, in the present invention, both asphalt concrete and cement concrete use aggregate whose particle size is controlled.The difference is that asphalt concrete mixes asphalt and stone powder, whereas cement concrete uses aggregate with controlled particle size. The purpose of this project is to propose a device that can also produce asphalt mix and ready-mixed concrete using the basic equipment as a device for producing asphalt mix, focusing on the fact that it only involves mixing cement, water, and admixtures. be.

[Means for Solving the Problems] In view of the above points, the present invention has the following features in order to solve the above problems:
An aggregate measuring tank is located below the cold hopper at the lower end of the drum for heating and mixing aggregates, into which an asphalt injection nozzle is inserted and is tiltably supported for one rotation.Cement measuring tank is used to measure cement and water, which will be mixed with fresh concrete. A tank and a water measuring tank are arranged, and a mixer is arranged below the measuring tank, while a blower is arranged in the cold hopper, and an exhaust flue for discharging exhaust gas is arranged near the center of the drum. Connect.

When manufacturing asphalt mix, a predetermined amount of aggregate and stone powder of various particle sizes are cut out according to the composition of the asphalt mix to be shipped, and fed to a drum for heating and mixing the aggregate while being weighed, and heated to a high temperature in the drum. At the same time, a predetermined amount of asphalt is injected into the drum, and the mixture is adjusted as it tumbles down the drum.Also, when producing ready-mixed concrete, aggregates of various particle sizes are cut out according to the mix of ready-mixed concrete to be shipped, and the aggregates are weighed and mixed. The aggregate was supplied to a drum for heating and mixing materials, heated at a relatively low temperature in the front half of the drum, brought to a surface dry state with only the surface water of the aggregate evaporated, and cooled in the rear half of the drum by cooling air sent from the cold hopper side. Asphalt mixture and ready-mixed concrete are characterized in that they are discharged from the drum in a timely manner, weighed in a predetermined amount in an aggregate measuring tank, and then put into a mixer together with cement and water measured in a cement measuring tank and a water measuring tank for mixing and adjustment. A manufacturing method is provided.

In addition, the present invention provides an aggregate measuring tank and cement and water, which are mixed materials for ready-mixed concrete, under a cold hopper at the lower end of an aggregate heating drum in which an asphalt injection nozzle is inserted and is tiltably supported for one rotation. A cement measuring tank and a water measuring tank are arranged to be measured, and a mixer is arranged below the measuring tank, and a blower is arranged in the cold hopper to send air for cooling the heated aggregate into the drum. Through holes are bored at appropriate intervals along the peripheral wall near the center of the drum, and the through holes are surrounded by a cover body from the outer periphery, and exhaust smoke is placed at an appropriate position on the cover body to guide the exhaust gas to the downstream dust collector. The purpose is to provide a patented Aldo mix material and ready-mixed concrete manufacturing device that is characterized by connecting roads.

[Function] According to the present invention, when producing asphalt mixture, aggregate (crushed stone, sand) and stone powder are cut out in an appropriate ratio according to the composition of the asphalt mixture to be shipped, and used for heating and mixing the aggregate. The materials are metered and supplied into the drum, and each material is heated by the high-temperature gas that passes through the drum.Asphalt is injected into each material from the injection nozzle installed inside the drum, and each material rolls inside the drum. While flowing down, the mixture is adjusted and discharged from the cold hopper side at the lower end of the drum.

In addition, when producing ready-mixed concrete, aggregates (crushed stone, sand) are cut out according to the composition of the ready-mixed concrete to be shipped, and fed to a drum for heating and mixing aggregates while being weighed. At this time, the key point is not to heat the aggregate in the drum to raise its temperature, but to send in hot air to the extent that only the surface water adhering to the surface of the aggregate evaporates. In other words, it is preferable to keep the aggregate in a so-called surface-dry state, where there is no moisture on the surface of the aggregate and the internal voids are filled with water.
The aggregate, which has been heated to a surface-dry state in the front half of the drum, is cooled to a temperature suitable for mixing ready-mixed concrete in the rear half of the drum by cooling air sent from the cold hopper side, and then transferred to the lower part of the cold hopper. Temporarily stored,
At the appropriate time, the aggregate is weighed in the aggregate measuring tank below the cold hopper, and then put into a mixer together with the cement and water measured in the cement measuring tank and water measuring tank, and mixed for a predetermined period of time to produce ready-mixed concrete.

[Example] Embodiments of the present invention will be described below based on the drawings.

Reference numeral 1 denotes a dryer for heating and mixing aggregates, in which a cylindrical drum 3 having a large number of scraping blades 2 arranged around its inner periphery is rotatably supported at an angle, and is moved at a predetermined position by a drive device (not shown). It is rotating at a speed of . A burner 5 is disposed at the upper end of the drum 3 via a combustion chamber 4, and a cold hopper 6 for temporarily storing aggregate is disposed at the lower end of the drum 3. Cooling air is supplied to the hopper 6 from the drum 3.
A damper 8 for adjusting the air volume is provided with a blower 7 that blows the air into the air.
This allows the amount of air sent into the drum 3 to be adjusted. Through-holes 9 are bored at suitable intervals in the peripheral wall near the center of the drum 3, and the through-holes 9 are surrounded by a cover 1O which is fixed and separated from the drum 3 from the outer periphery. An exhaust flue 12 equipped with an air volume adjustment damper 11 is connected to the cover body 10, and downstream of the exhaust flue 12 are a dust collector 13 for capturing scattered dust, an exhaust air fi 14 for gas suction, and a chimney 15 are arranged, and a burner 5
While the high-temperature gas is sent into the drum 3, the exhaust gas that has passed through the drum 3 is sucked in by the exhaust fan 14 disposed downstream, and is passed through the through hole 9 drilled in the peripheral wall near the center of the drum 3 to the cover body 10. The air is exhausted through the exhaust flue 12. Reference numerals 16a to 16d are hoppers for storing aggregate according to particle size. A variable speed feeder 17 disposed below each hopper cuts out a predetermined amount of aggregate, and while it is weighed by a weighing conveyor 18, the aggregate is transferred to conveyors 19 and 20. It is supplied into the drum 3 through the drum 3. Reference numeral 21 denotes a stone powder storage bin for storing stone powder, which is one of the materials for asphalt mixture.
2. It is fed onto the belt conveyor 19 via the weighing conveyor 23 and into the drum 3 together with the aggregate. An asphalt injection nozzle 24 injects asphalt into the aggregate supplied into the drum 3 during the production of asphalt mixture, and is connected to an asphalt tank (not shown) via an asphalt supply pipe 25. 26 is an aggregate measuring tank disposed below the discharge gate 27 of the cold hopper 6, which passes through the inside of the drum 3 to the cold hopper 6.
This is to measure a predetermined amount of aggregate temporarily stored in the tank.

28 is a cement measuring tank for measuring cement, which is one of the raw materials for fresh concrete, and is a cement storage silo (
The cement taken out from the cement storage bin 29 (not shown) was temporarily stored in a cement storage bin 29, and the cement stored in the cement storage bin 29 was discharged and weighed in a predetermined amount, and was placed below the aggregate measuring tank by a screw feeder 30. Pour into mixer 31. Reference numeral 32 denotes a water measuring tank for measuring mixing water for fresh concrete.Water is supplied from a water tank 33 disposed above, measures a predetermined amount, and is pumped into the mixer 3 by a pump 34.
Add water to 1. Further, an admixture measuring tank (not shown) is arranged above the water measuring tank 32, and a predetermined amount of the admixture is put into the water measuring tank 32 and mixed with water for use. The mixer 31 is a two-shaft mixer capable of kneading both asphalt mixture and fresh concrete, and has two kneading shafts 35 arranged in parallel between opposing side walls of the kneading tank.
are rotated in opposite directions, and the kneaded material is moved along the axial direction while being scraped up by kneading blades 36 attached to a kneading shaft 35 for kneading.

This type of twin-shaft mixer is used in both asphalt plants and batcher plants, and although there are slight differences in the shaft seal, arrangement of mixing blades, shape, etc., it can handle both asphalt mix and ready-mixed concrete. It is possible to construct a twin-screw mixer for kneading, and a mixer that can knead both materials is used.

Therefore, when producing asphalt mix, the aggregate hopper 16a-1 is adjusted according to the mix of the asphalt mix to be shipped, similar to the conventional drum mixing method.
From 6d, predetermined aggregate (crushed stone, sand) is fed to the variable speed feeder 17.
At the same time, a predetermined amount of stone powder is dispensed from the stone powder storage bin 21 by the variable speed feeder 22, and each material is fed into the drum 3 via the conveyor 19.20 while being weighed by the weighing conveyor 18.23. The aggregate supplied into the drum 3 is heated by hot air from the burner 5 in the front half of the drum 3, and asphalt is injected from the asphalt injection nozzle 24, and the aggregate is rolled inside the drum 3 in the rear half of the drum 3. While flowing down, the mixture is adjusted and temporarily stored in the lower part of the cold hopper 6, and is discharged as an asphalt mixture by opening and closing the discharge gate 27. At this time, the aggregate measuring tank 26 and the mixer 31
If it is not necessary to measure and mix the asphalt mixture in I!, the aggregate measuring tank 26 and mixer 31 are made horizontally movable, and the discharged asphalt mixture is measured as aggregate I! 2
6 and the mixer 31. In this case, the mixer 31 may be one that can mix only fresh concrete. Also, the mixer 31 may be equipped with an asphalt injection nozzle, and the mixer 31 may be configured to mix asphalt. It is also possible to produce an asphalt mixture by measuring a predetermined amount of heat-dried aggregate in the aggregate measuring tank 26, feeding it into the mixer 31, spraying and mixing a predetermined amount of asphalt, and adjusting the kneading in the mixer 31.

When producing ready-mixed concrete, a predetermined amount of aggregate is cut out from aggregate hoppers 16a-16d using variable speed feeders 17a-17d according to the mix of ready-mixed concrete to be shipped, and conveyed to conveyor 19 while being weighed by weighing conveyor 18.
．． 20 into the drum 3 and heated with hot air from the burner 5. However, the water/cement ratio in concrete is different from that in which the aggregate is heated to a high temperature as in the production of asphalt mix mentioned above. strength of concrete,
It is an important factor in determining the slump value, and it is no exaggeration to say that the moisture management of the aggregate is the most important during the production of ready-mixed concrete. It goes without saying that the desired water/cement ratio cannot be achieved unless the amount of surface water adhering to the cement is calculated and the amount of surface water is subtracted from the amount of water designed for blending and used as the mixing water. However, it is impossible to constantly sample the surface water percentage of aggregate and feed back this surface water percentage to reflect it in the water amount value correction.

Therefore, we changed the idea and evaporated the water on the surface of the aggregate to create a state where there is no water on the surface of the aggregate and only the internal voids are filled with water, a so-called surface dry state. There is no need to constantly sample water, and we think that subsequent moisture management will be easier. Therefore, when heating the aggregates in the drum 3, the burner 5 is designed to evaporate only the water adhering to the surface of the aggregates and send relatively low-temperature hot air so that the aggregates are surface-dry. It is necessary to control the amount of combustion. It is thought that this combustion amount control can be controlled if information such as the amount of aggregate supplied, the surface water rate, and the temperature of aggregate discharged from the dryer can be obtained. However, if the surface water percentage fluctuates greatly, it may not be possible to always maintain a surface dry state even during continuous operation, but if the aggregate can be maintained near a surface dry state, the surface water It is thought that more severe moisture management can be achieved than the method of occasionally sampling and measuring the water rate and feeding it back to the measured water value. The temperature of the aggregate heated by hot air in the first half of the drum 3 to a surface dry state is high to some extent, and it is unsuitable for use in the production of ready-mixed concrete. This will cause some of the fresh concrete to evaporate or increase the temperature of fresh concrete during mixing, which will have an adverse effect on the production of high-quality concrete. The heated aggregate is fed into the drum 3 while adjusting the airflow, and is exhausted from the exhaust flue in the center of the drum 3, so that the aggregate temperature is lowered while the heated aggregate passes through the rear half of the drum 3. Then, this aggregate is temporarily stored in the cold hopper 6, and the discharge gate 27 is opened and closed at appropriate times to discharge the aggregate downward, and a predetermined amount is measured in the aggregate measuring tank 26 and thrown into the mixer 31. Measuring tank 2
Add the predetermined amount of cement measured in step 8 to screw feeder 3.
0 into the mixer 31, and the amount of water designed to be mixed in the water measuring tank 32 is measured.The aggregate is in a surface dry state and there is no need to correct the surface water ratio, but just to be sure, (You can also sample the aggregate, measure the surface water content, and feed this back to correct the surface water content.)
The concrete is put into a mixer 31 by a pump 34 and kneaded for a predetermined period of time to produce ready-mixed concrete.

It is most preferable to heat the aggregate in the dryer 1 so that it becomes surface-dry, but since it is practically impossible to detect this state, it is preferable to heat the aggregate in a wet state so that the temperature does not rise too much. The desired purpose can be achieved to some extent by heating the sand to a certain degree and making it smooth.
Combustion management within the scope of the present invention is included in the present invention.

[Effects of the invention] As described above, in the present invention, both asphalt mixture and ready-mixed concrete can be produced in a single plant, so the initial cost of the plant is low and there are great economic advantages. It is.

In addition, when producing ready-mixed concrete, wet aggregate is heated in a dryer to bring it close to a surface-dry state where surface water has evaporated, making the water/cement ratio, an important factor in concrete, more severe. It is something that can be managed.

[Brief explanation of the drawing]

FIG. 1 is a schematic explanatory diagram of an embodiment of the apparatus of the present invention, and FIG. 2 is an enlarged sectional view taken along the line A--A in FIG. l... Dryer 2... Scraping blade 3... Drum 5... Burner 6... Cold hopper 7...
・Blower 9...Through hole 1O...Cover body 12...
・Exhaust flue 13... Dust collector 16a-16d... Aggregate hopper 24... Asphalt injection nozzle 26...
・Aggregate measuring tank 28... Cement measuring tank 32...
Water measuring tank 31...mixer

Claims (2)

[Claims] (1) Insert the asphalt injection nozzle and measure the cement and water that will be mixed into the fresh concrete in the aggregate measuring tank below the cold hopper at the lower end of the drum for heating and mixing aggregates, which is rotatably supported at an angle. A cement measuring tank and a water measuring tank are installed, and a mixer is installed below the measuring tank, while a blower is installed in the cold hopper, and an exhaust smoker for discharging exhaust gas is installed near the center of the drum. connect roads,
When manufacturing asphalt mix, a predetermined amount of aggregate and stone powder of various particle sizes are cut out according to the composition of the asphalt mix to be shipped, and fed to a drum for heating and mixing the aggregate while being weighed, and heated to a high temperature in the drum. At the same time, a predetermined amount of asphalt is injected into the drum, and the mixture is adjusted as it tumbles down the drum.Also, when producing ready-mixed concrete, aggregates of various particle sizes are cut out according to the mix of ready-mixed concrete to be shipped, and the aggregates are weighed and mixed. The aggregate was supplied to a drum for heating and mixing materials, heated at a relatively low temperature in the front half of the drum, brought to a surface dry state with only the surface water of the aggregate evaporated, and cooled in the rear half of the drum by cooling air sent from the cold hopper side. Asphalt mixture and ready-mixed concrete are characterized in that they are discharged from the drum in a timely manner, weighed in a predetermined amount in an aggregate measuring tank, and then put into a mixer together with cement and water measured in a cement measuring tank and a water measuring tank for mixing and adjustment. Production method. (2) Insert the asphalt injection nozzle and measure the cement and water, which will be mixed into the fresh concrete, in the aggregate measuring tank below the cold hopper at the lower end of the drum for heating and mixing aggregates, which is rotatably supported at an angle. A cement measuring tank and a water measuring tank are installed, and a mixer is installed below the measuring tank.A blower is installed in the cold hopper to blow air for cooling the heated aggregate into the drum. Through holes are bored at appropriate intervals along the peripheral wall near the center, the through holes are surrounded from the outer periphery by a cover body, and an exhaust flue is provided at an appropriate position on the cover body to guide exhaust gas to a downstream dust collector. Asphalt mixture and ready-mixed concrete production equipment characterized by being connected.