LOUSIOS, Christos (8th Km. Ptolemaida-Florina, Ptolemaida, GR-502 00, GR)
| CLAIMS
1. Semi-trailer various - grades fresh concrete production plant comprises of a chassis ( 1 ) fitted with two axles and four wheels. It is used for mounting the machinery producing fresh, ready-to-use concrete. This machinery includes the aggregates store (2), two conveyor belts (19) (5) one of them having variable length (5), a mixer (6), a control cab (3), a telescopic armsfitted hydraulic lifting system (7) , a diesel generator (8), a water / cement / admixtures weighing system (4), a large water tank (24), and a small lifting rig (9). It features production of several fresh concrete grades, loading of aggregates by a single loader and furthermore the unit can be towed and thus transported to any location.
2. Semi-trailer various - grades fresh concrete production plant in accordance with claim 1 is characterized by the fact that it can be ground-transported to any location using a semi-trailer tractor, since its dimensions are within Traffic Code stipulated limits and can obtain a load going license.
3. Semi-trailer various - grades fresh concrete production plant in accordance with claim 1 is characterized by the fact that it is fitted with four aggregate compartments (17); aggregates are fed through the top and discharge through their bottom. The layout of aggregates compartments is shown in 5.
4. Semi-trailer various - grades fresh concrete production plant pursuant to claims 1 and 3 is characterized by the fact that the aforesaid four aggregate compartments (17), can be fed with four different types of aggregates, allowing the production of several fresh concrete compositions.
5. Semi-trailer various - grades fresh concrete production plant, pursuant to claims I and 3, is characterized by the fact that width of each compartment is 3,25m; thus, aggregates can be loaded by a single loader.
6. Semi-trailer various - grades fresh concrete production plant, pursuant to claims 1 and 3 is characterized by the fact that aggregates store (2) is fitted with two opening side parapets (10) and five vertical dividers (14).
7. Semi-trailer various - grades fresh concrete production plant, in accordance with claim 1 is characterized by the fact that it is fitted with two conveyor belts (19) (5), whereas length of one of them is variable (5).
8. Semi-trailer various - grades fresh concrete production plant in accordance with claim 1 is characterized by the fact that it incorporates a control cab (3) located on ground surface at some distance from the plant.
„. 9. Semi-trailer various - grades fresh concrete production plant pursuant to claims 1 and 8 features an air - conditioned control cab (3), and a wired or remote controlled communication link with the semi-trailer.
10. Semi-trailer various - grades fresh concrete production plant in accordance with claim 1 is characterized by the fact that it is fitted with a telescopic arms hydraulic system (7) used to raise the mixer at various heights (from 2m to 3,7m) and lengths (from Om to 2m) so that the position of fresh concrete discharge may be adjusted, to allow easy loading to different types of vehicles.
1 1 Semi-trailer various - grades fresh concrete production plant, in accordance with claim I , is characterized by the fact that the large water tank (24) in conjunction with storage compartments (25) are located on the base where aggregates stores are also supported.
12. Semi-trailer various - grades fresh concrete production plant in accordance with claim 1 is characterized by the fact that the common twin - axial horizontal mixer is used, with blades rotating to opposite directions. |
SEMI-TRAILER PLANT FOR THE PRODUCTION OF VARIOUS FRESH
CONCRETE GRADES
This invention refers to a plant used to produce ready-to-use fresh concrete, when fed with the appropriate raw materials; it can be easily transported since it is attached upon a semi-trailer vehicle.
Concrete is in fact a mixture of aggregates, water, cement and admixtures. Tt is used for the construction of buildings, bridges, port facilities and other structural buildings. It is nevertheless characterized by the following two attributes: it must be used in 30 minutes following mixing, so that the final product ( concrete ) obtains optimal mechanical properties.
Fresh concrete is produced by a stationary plant assembly, permanently installed in a software area; special vehicles are used for pickup, transport and distribution of concrete at the various positions where it is to be used. The interval from the moment of production until it is poured shall not exceed 30 minutes, otherwise the stationary concrete plant must be must be transferred closer to the concrete consumption location; however such transfer is costly and time-consuming. When transferring concrete to island locations this problem is aggravated.
Several patents have tried to solve such transport problem by employing several ways. US pat No 6186654 uses two semi-trailer vehicles, however these are suitable for high fresh concrete hourly capacities; their transport to island locations in particular is costly. US pat No 5730523 employs a concrete mixing barrel attached on a semi-trailer; however the quantity of fresh concrete produced in this case is not as satisfactory as if a mixer were used. US Pat No 6991361 refers to fresh concrete production on a semi-trailer. Nevertheless all patents use three separate vessels i.e. compartments for ballast, yet none of them employs four compartments on a single semi-trailer, whose dimensions are sufficient to allow aggregates loading even by a single loader.
The present invention is used for production of fresh concrete on-board a semi-trailer; the latter can be transported to any site, can obtain road - going license whereas its dimensions meet Traffic Code provisions and no special road license is required.
It is fitted with the following :
An aggregate store with auxiliary parapets. This store has four aggregate compartments and can simultaneously process four types of aggregates. Width of each compartment is 3,25m, thus aggregates may be loaded by a single loader.
Control cab located remotely on the ground. It is situated at remote location, fitted with air - conditioning; control commands can be transmitted by wired or wireless remote control connection
Hydraulic system with telescopic arms used to locate the mixer at its operating position, or at other height above the ground (from 2m to 3,7m).
Two belt conveyors, one of them having variable length
Aggregate tray is supported by a large water tank and a storage compartment.
A system comprising of telescopic arms used to raised the mixer at a variable height above the ground, depending on the case, so that fresh concrete outlet elevation can be adjusted to facilitate loading on transport vehicles of various types.
A common horizontal twin - axial mixer, whose blades are rotating to the opposite direction.
This patent offers the folloλving benefits:
Firstly, due to the fact that it employs four compartments for aggregates handling, a variety of fresh concrete grades can be produced, i.e. fresh concrete types can contain four ' ballast graduations, for instance, or fresh concrete may contain lignite fly ash. Concrete grades containing fly ash are used in construction of dams, in waterproofing of artificial ponds, in port works and various other technical works, since their use serves to significant reduce construction cost, while fresh concrete quality remains satisfactory. Lignite fly ash can be transferred from a ground-located silo to an compartment using a screw conveyor.
Secondly, locations in several parts of the world are lacking quarries, yet sand aggregate mines can be found. Such sand mined produce gravel, gravel graduations and sand. Sand gradation may bot be suitable for fresh concrete production, however when employing two sand mines located at different areas, producing different graduations of sand, one may produce a sand blend that is suitable for fresh concrete production. Using the current four aggregate compartments on the semi-trailer, two of the compartments can be used to load sand from two different sand mines, while the remaining two compartments may contain ballast; using computer software one may calculate the appropriate mixing ratios for fresh concrete production.
A third reason necessitating the utilization of four compartments is that quarry sand may contain powder to a rate exceeding the allowed limit; however when mixed with washed sand, the " resulting sand has appropriate powder content such as to allow fresh concrete production. Therefore, two compartments are used to contain two types of sand while the remaining two may contain the remaining ballast. Instead of washed sand, quarry sand may be also used, since powder content of the latter is extremely low. Using the fourth
compartment, fresh concrete types containing silica powder or steel mill slag can be produced.
A fourth attribute is that the control cab is air - conditioned and installed on the ground; this way operator is isolated from semi-trailer noise and vibration; communication with the semi-trailer is effected through cable or remote control link
A fifth attribute is that the end product can be loaded to any transport vehicle. This is due to the fact that using a hydraulic lifting system featuring telescopic arms, product dropping height and length can be adjusted, between 2m to 3,7m and Om to 2m, respectively.
A sixth attribute is that for the present invention, loading of aggregates on the semitrailer various fresh concrete grades production plant, can be performed using a single loader. Nevertheless the need to provide on-site three ground - installed large silos with their transport gear is eliminated, whereas in the latter case these three large silos would require a dedicated loader to feed them with aggregates.
Figure 1 shows the travel position layout of the semi-trailer various grades fresh concrete mixing plant.
Figure 2 shows a pian view of the travel position layout.
Figure 3 shows operating position.
Figure 4 shows a detailed drawing of the plant in operating position.
Figure 5 shows a perspective drawing of the aggregate tray
Figure 6 shows a perspective drawing of the mixer
Figure 7 shows a sectional view of the travel position layout.
Semi-trailer production plant for various fresh concrete grades is shown in figure 1 in road travel layout. It comprises of a frame (1) fitted with two axles and four wheels, suitable to support gross weight of the plant. Aggregates store (2) is supported on the frame, whereas the control cab (3) is located in front of it. The same figure shows the water / cement / admixtures weighing system (4), comprising of a cement silo, an admixtures silo and a water tank, the variable length conveyor (5), the mixer (6), the hydraulic lifting system complete with telescopic arms (7), diesel generator (8), and a small lifting rig (9). Overall dimensions of the plant are 13700mm long, 2500mm wide and 4000mm high; its capacity is maximum 60 cu.m. of concrete per hour, and can be transported by appropriate tractor e.g. regular semi-trailer tractor on roads as well as in project site areas. Center of gravity of the plant is located low. No special road permit is required. Figure 2 shows a plan view of the road travel layout. It furthermore shows the side parapets of the aggregates store (10), water / cement / admixtures weighing system (4), the latter consisting of cement silo (23), a small water tank (22), and the chemical admixtures silo (11).
When the vehicle is transported to the operations site (figure 3), and after extending the hydraulic outriggers (12), located at the front of the frame (two outriggers) the tractor can be decoupled. Then, the remaining six outriggers can be installed ( 13). Water / cement / admixtures weighing system (4), is located using the small lifting rig (9) at its mounting position, installed upon the mixer (6). Using the telescopic armsfitted hydraulic lifting system installed on the (7) semi-trailer production plant, mixer can be raised from the travel position to the working position. Then, using the small hoisting rig (9) control cab (3) can be mounted on the ground at a distance from the semi-trailer various - grades fresh concrete production plant; the two side parapets (10) and (fig. 4) the five perpendicular parapets on the aggregates store (14). Now fresh concrete can be produced, provided that it is supplied with raw materials.
Aggregates store (figure 4) is divided into four compartments (16). Each compartment is split in two so that two cone - shaped sections are formed therein (17). Each cone section is fitted with a bottom port that can open through a suspended door.(18). Each one of the four compartments can be filled from the top with a type of aggregate; after opening of doors (18) such materials are dropped down, and after passing through the tray
(20) they end up on the fixed conveyor belt (19) as shown in figure 4 . This way, four types , of aggregates can be used for fresh concrete production and therefore a large variety of concrete types can be produced. Aggregates comprise of sand, several other sand or stone ° graduations. Doors are moving through pneumatic rams (28), they simultaneously open and,' close in each cone section; upon closing action they initially move fast and the gradually., close at lower speed in order to improve weighing accuracy. Four vibrators are provided, • , one in each compartment of the aggregates store; these operate while aggregates are in.'- transit so that they are eventually dropped on the fixed conveyor belt; in each compartment of the aggregates store a humidity sensor is provided to measure aggregates humidity. Aggregates store is fitted with auxiliary retractable parapets, these are permanently installed (29) used to increase store capacity.
Weight of sand that can be stored in any compartment of the aggregates store (2) is weighed using the following mechanism. A weighing tray is provided, mounted on four supports fitted with sensors on the underside of the aggregates store. Fixed length conveyor is suspended on the weighing tray using four additional studs. Sensor probes weigh the combination of tray and conveyor. When sand is dropped and after opening the gates, it is amassed on the conveyor and then in the tray (20). Flaps are installed in the tray
(21) to protect the conveyor against impact induced by the weight of sand. In case conveyor is not loaded with the correct sand weight, then the suspended gates previously
' opening to allow sand discharge will not close and appropriate command is issued to the control cab. All the above are illustrating the operational mode of the weighing system when an aggregate type is loaded in a section of the store; sand has been used by way of example. The same procedure shall apply to weighing of other aggregates located in the
four compartments of the store. Aggregates shall be successively weighed one by one, separately before forwarded by the fixed conveyor belt to the telescopic conveyor.
Using the above method (i.e. utilization of the tray) allows both directing aggregates on the fixed conveyor belt, and furthermore induces an additional mixing of aggregates as follows: upon commencement of fixed conveyor belt motion, aggregates accumulated on the four areas of the tray are simultaneously moving slowly downwards.
Above the mixer, figure 3 the small water tank (22) containing 300 liters situated next to the cement silo (23), is used to feed water to the mixer. On top of this tank, a system is installed for weighing water incoming to the mixer. Measurement system consists of three sensing probes continuously weighing the tank and its content. The underside of this tank is fitted with an opening allowing water discharge when a relevant solenoid is opened, so that it is routed to the mixer. Water weight measurement system controls the above solenoid. Water downstream of the solenoid is driven to a pump; the latter is employed so as to increase water pressure. Then, water is channeled to a pipe located on the upper, inner part of the of the mixer, fitted with an injector. This way, a significant water quantity can be injected over the mix in a short period, thanks to high water pressure. Water tank is supplied with water through the large SOOOlit tank, using pump and charging system, located in the stores. The large water tank as well as the materials store (25) are also used as, support base of the aggregates store. Tank is filled with water through a 2" intake.
A second water pump is picking up water from the large water tank in order to feed the same to the vehicles loading with fresh concrete , if needed.
Cement silo (23) has two inlet ports at the top and an outlet at the bottom. One or two screw conveyors are outgoing at ground level; these transport cement to the respective silo (23) (not shown in drawings). Its capacity is 600kgr. A mechanism is fitted on the underside and this includes a pneumatic ram which is used to open a flap; opening of the latter allows dosing of cement so it can be fed to the mixer. A cement weighing system is provided; this comprises three sensing probes weighing the silo and its content. Each time sensing probes issue a command to the ground cement feeder system so that the latter drives a suitable quantity to the silo. A vibrator is installed on top of the cement silo; this is operating for the necessary period until silo is fully discharged. When cement is dropped into the mixer, a dust cloud is generated. This could escape from the mixer, however a pipe is provided to connect the upper part of the mixer and the upper part of the cement silo; thus dust is instead returning through the mixer and back into the cement silo. Moreover this pipe helps to equalize air pressure values between cement silo and mixer.
The area containing admixtures (11) is located above the 3001Lt small water tank.
Chemical admixtures silo is fitted with a sensor -equipped weighing system whose purpose
is to weight the silo and its content.
Three pumps installed on the semi-trailer fresh concrete production plant are fitted with hoses; each of them may individually feed three different admixtures types to the admixtures silo. When admixtures silo (11) is filled with the required quantity, then weighing system of the latter issues a stopping command to the pumps. Using appropriate pipe, these admixtures are driven out of the cement silo and into the mixer. These three pumps are fed with admixtures from three separate tanks situated on the ground; they are not part of the semi-trailer fresh concrete mixing plant.
Two telescopic arms are affixed on the platform chassis; these can be simultaneously extended using a hydraulic ram. The latter is driven by a hydraulic pump, electric power - supplied by the diesel generator. The aforesaid two telescopic arms are permanently attached to the mixer; when extended they also cause a movement of the telescopic belt conveyors and the latter is picking up aggregates from the fixed conveyor belt and conveys them into the mixer.
Mixer is of the twin - axial type; its blades are rotating to the opposite direction,, thus driving the mix downwards. It is fitted with a control port at the top; its internal parts, are fitted with friction - resistant material. Two electric motors fitted with electric drives are; used to rotate two shafts of the mixer. The mixer underside is fitted with a port; movement of the latter creates an opening to allow exit of fresh concrete. The mechanism of this port is driven by a pneumatic ram.
When mixer is need of flushing, then the injection water supply system is employed; an additional water supply is also provided to allow flushing from the control port.
The control and operations room includes office, computer and an air - conditioner. This room is located remotely with respect to semi-trailer production plant for various types of fresh concrete to protect the computer against weather effects; hardwired communication is provided between the plant and the room.
Semi-trailer production plant for various grades of fresh concrete is also fitted with cement screw conveyors (31) as shown in figure 7.
A 150 kVA diesel generator (8) adequately accommodates all power needs of the plant; generator is fitted with own fuel oil reservoir. If it is practical to provide the semitrailer various - grades fresh concrete production plant with external mains power, then diesel generator is not used.
An electric air compressor is used to feed the compressed air network with 6 atm pressure.
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