Patent Application
20100193543
It is common in the concrete mixture production industry to mix a coloring agent with concrete mixtures prior to such mixtures being transported to a job site via ready-mix trucks.
To be sure that the color of the concrete is of the exact shade ordered by the customer, it is critical that the coloring agent be dispensed to the concrete mixture in a precise quantity. One method of attempting to achieve this aim is illustrated in
Another prior art of attempting to dispense precise amounts of coloring agents to a concrete mixture is illustrated in
Accordingly, there is a need for a system for providing liquid coloring agent to concrete mixtures within delivery vehicles which avoids the aforementioned problems in the prior art.
The invention satisfies this need. The invention is a system for providing liquid coloring agent to concrete delivery vehicles. The invention comprises a system for providing liquid coloring agent to concrete delivery vehicles parked in a loading zone, the system comprising (a) a plurality of bulk tanks, (b) a weighing vessel connected in fluid tight communication with each bulk tank, and (c) a fill line connecting each weighing vessel to the loading zone.
In a preferred embodiment of the invention, the weighing vessel has a capacity between about 40 and about 80 gallons and comprises one or more load cells which communicate to a PLC.
These and other features, aspects and advantages of the present invention will become better understood with reference to the following description, appended claims and accompanying drawings where:
The following discussion describes in detail one embodiment of the invention and several variations of that embodiment. This discussion should not be construed, however, as limiting the invention to those particular embodiments. Practitioners skilled in the art will recognize numerous other embodiments as well.
The invention is a system 10 for providing liquid coloring agent to concrete mixtures within concrete delivery vehicles 12 vehicles parked in a loading zone 14. The system 10 comprises a plurality of bulk tanks 16 and a weighing vessel 18 associated with each bulk tank 16.
Typically, the system 10 comprises four-eight bulk tanks 16, but fewer bulk tanks 16 or a larger number of bulk tanks 16 can also be used in the system 10. Each bulk tank 16 is a storage tank which typically holds between about 300 and about 500 gallons of liquid coloring agent.
Each weighing vessel 18 in the system 10 typically holds between about 40 and about 80 gallons of liquid coloring agent. This capacity is calculated to allow the user to employ each weighing vessel 18 near about 60% of the capacity of each weighing vessel 18. This, in turn, allows the user to comfortably operate above about 20% of the capacity of each weighing vessel 18 and below about 80% of the capacity of each weighing vessel 18, so as to avoid the drawing of air into a weighing vessel 18 (in the event the weighing vessel 18 is inadvertently emptied) and so as to avoid the inadvertent overfilling a weighing vessel 18. The ability in the user to not have to worry about drawing air into the weighing vessel 18 and overfilling a weighing vessel 18 permits the user to cycle each weighing vessel 18 more quickly. This preferred capacity of the weighing vessels 18 in the system 10 is significantly larger than the typical capacity of prior art systems 10 used in the weighing vessel 18, such as weighing vessel 204 illustrated in
Each weighing vessel 18 is mounted on a scale base 20 comprising a mounting plate 22 and one or more load cells 24. Each load cell 24 comprises a transducer capable of converting force into measurable electrical output. In a typical construction, the load cells 24 are strain gauge-based load cells 24. In one embodiment, the load cells 24 are operatively connected to a typical scale head 26 commonly known in the prior art. Such connection scheme is illustrated in
Preferably, the load cells 24 beneath each weighing vessel 18 are operatively connected as illustrated in
The PLC 30 can directly read voltage changes between each of the load cells 24 because of the attached stable direct current power supply 28 which provides an accurate measure of pigment within the weighing vessel 18. The PLC 30 can measure pigment within about 45 grams of the desired amount. The connection scheme illustrated in
Moreover, the connection scheme illustrated in
Finally, the connection scheme illustrated in
As illustrated in
In operation, coloring agent from each bulk tank 16 is transferred to a weighing vessel 18 in an amount approximately equal to 60% of the capacity of such weighing vessel 18. Thereafter, as trucks 12 carrying concrete mixtures arrive at the loading zone 14 for a respective coloring agent, coloring agent is quickly transferred from the appropriate weighing vessel 18 to the truck 12 without having to waste time worrying about whether the weighing vessel 18 might be completely depleted (so as to risk drawing air into the weighing vessel 18) and, as the weighing vessel 18 is re-filled after transferring an appropriate designated quantity of coloring agent to a waiting ready-mix truck, not having to worry about whether the weighing tank 18 is being inadvertently overfilled. Adding coloring agent to a second truck 12 which immediately follows the first truck 12 is also made faster in the system 10 of the invention due to the fact that no time need be wasted in rinsing out a weighing vessel 18 with water.
The system 10 of the invention is accordingly considerably less expensive to build and maintain than systems of the prior art. It provides faster loading operation into waiting trucks and it provides an accuracy of measurement considerably better than most systems of the prior art.
Having thus described the invention, it should be apparent that numerous structural modifications and adaptations may be resorted to without departing from the scope and fair meaning of the instant invention as set forth hereinabove and as described hereinbelow by the claims.
