METHOD FOR CONTROLLING CONCRETE WASHING WATER BACKGROUND OF THE "INVENTION". The present invention relates to a method for controlling the wash water of concrete, for example the water used to produce an already mixed concrete or a precast concrete, by washing a mixing drum or another container in which the mixture was mixed. concrete or where it is adhered, the washing includes a wash water containing retarder the removal - of wash water aggregates, and the reuse of the wash water obtained in this way as part of a mixing water for a new batch of concrete, the next day or later, without discharging waste from the concrete plant. The invention allows the detection of excessive or insufficient amounts of retarder that are added to the wash water, and allows operators to instantly handle these circumstances. In accordance with the teachings of the prior art, Japanese Patent Publication (Kokai) No. Hei 2-263100 / 1990 (Patent No. 265137), it is known to wash a mixing apparatus. (where concrete is adhered) with a water containing retarder, separate the aggregates from the wash water, store the wash water obtained in this way in such a way that the concrete activity is retained there, and reuse the water of washing in mixing water for a new batch of concrete the next day or after the next day. At least 200 concrete plants are currently using this method and therefore have suspended the discharge of deactivated concrete waste. Since the generation of water contaminated with concrete has been suspended, environmental advantages as well as conservation of resources are obtained. However, concrete plants include many open-air operations, and the water content, aggregates, and other constituents of the concrete may vary from day to day. Sand and gravel are natural materials used in concrete, and their compositions may vary. Even though concrete is an industrial product, there are variations in the components due to. variations in the practices and materials of each manufacturer, due to the equipment of the concrete plant, and due to other factors. By . Consequently, precise control of concrete is difficult. Several types of concrete mixes have been developed and the concrete is produced in accordance with the specification of a construction company and transported by an agitator vehicle to the site, of the construction by trained technicians that are required for t sufficient control of the product. Also, the amount of retarder to add does not. It is fixed and can vary greatly due to changes in the seasons. For example, if the day after a. mixed and emptied is a holiday, a retarder will be added in significant quantity. Likewise, the concentration of solids can also greatly affect the. amount of retarder in the wash water. Thus, maintaining control of the amount of retarder added to concrete in the plant has been relatively difficult. In addition to these problems is the fact that pumps, which provide retarding materials from tanks, are located in open air and sometimes break due to the effects of wind and rain, and especially in the case of storms. Another factor to take into account is that many plants are not monitored during the night. Obviously there is also the possibility of errors caused by operator errors, which requires a double and triple revision. Thus, it is not surprising to find sometimes that retarders are sometimes added in quantities of 2 to 6 times greater than what is actually required. Concrete prepared with wash water containing such large amounts of retarder did not advance operations at the construction site due to the variable and often extended retardation of setting, and this is the., problem that frequently arises in the case of concrete plants. Another problem is that if the amount of retarder is insufficient, the concrete will lose part of its activity and when mixed with fresh concrete it is difficult to mix and this can cause a mixture of naturally deteriorated concrete. To maintain quality, the concrete supplier sometimes disposes of the concrete, which is an action contrary to the purpose of using a retarder technology to begin with. The control of the accuracy of the addition of retarders is an essential issue for the operations of the concrete plants, but it is far from perfect because the number of highly qualified technicians found in the concrete plants is sometimes not adequate . COMPENDIUM OF 1? INVENTION An object of the present invention is to avoid the problems of the prior art in terms of controlling the levels of retarders by providing sensors in a communication system to transmit a signal, which corresponds to the amount of retarder in a retarder tank, after to carry out an operation in which a retarder is mixed in a concrete (for example, concrete for ready mix: to be used or pre-cast), to a control center; and the signal that has detected the amount and concentration of the wash water in a slag tank to the control center are provided to avoid problems caused by the introduction of an excess of retarder during washing operations involving mixing drums, containers , or other devices where the concrete has been mixed with a water containing retarder, separate aggregates from the wash water and reuse the wash water obtained in this way as part of a mixing water or fresh concrete the following day and after. Thus, an object is to provide a method for controlling a concrete wash water, a method that includes detecting whether an excess or retarder insufficiency is added to the wash water. This allows the operator to adjust, thus avoiding the need to discard wasted concrete and / or wash water from the plant. The operator can wash the mixer or apparatus where it is found due to the concrete with a water containing retarder, remove the aggregates from the wash water, and reuse the wash water as part of a freshly made concrete mix water the next day. or after the - next day. An exemplary method of the invention therefore comprises the washing of an apparatus where the concrete is adhered with a water containing retarder, the removal of aggregates from the wash water and the reuse of the washed water as part of a mixed fresh concrete water. elaborated the next day or after the next day, the invention being characterized in that it offers, in a communication system connected to a control center, a first sensor that operates to transmit a signal to a control center, which corresponds to the amount of retarder of a retarder tank after the completion of operations (for example, after washing the mixer truck) and a second sensor in the communication system connected to a control center, the second sensor operates. to transmit a signal to the control center corresponding to the amount and / or concentration of wash water in a slag tank. The control center thus makes it possible to dose the retarder in the wash water tank in a precisely adjusted manner in order to: avoid problems that may be caused by the introduction of excessive amounts of retarder. Additional advantages and benefits of the invention will be better understood by taking into account the following detailed description. BRIEF DESCRIPTION OF THE DRAWING Figure 1 is a schematic diagram of a method and system of the present invention, wherein an exemplary residual wash water reuse system is connected to a control system which in turn may be, connected to one or more waste water reuse systems. DETAILED DESCRIPTION OF EXEMPLARY MODALITIES a concrete plant, after the washing of the last mixer truck or bie. another concrete transport vehicle, it is now possible, through the application of the method and system of the present invention, to avoid the generation of litter water waste at night. Figure 1 illustrates that two or more exemplary residual wash water reuse systems (each system comprises the components generally designated 1-6,8,9 and 11) may be connected to a control system 10, which may be in the same location or in a different location Alternatively, the two sets of residual wash water reuse systems may be in the same location or in different locations between them, and / or in the same location or in different locations with respect to the control system 10. For example, the control system 10 may be connected to any number of different users (ie, different waste water reuse systems) by telephone or Internet- After the use of washing water to wash the last truck for the operation corresponding to a given day, all the washing water 2 is stored in a washing water tank 5, as shown in figure 1, and slowly stirred in the presence of a necessary and sufficient quantity of a retarder. Based on the concentration of concrete - in - the wash water that receives an exact amount of retarder, the amount of wash water to be used in the fresh concrete mixture is calculated the next day, together with the quantities of concrete. "and fresh water to be reduced in accordance with this data." Accordingly, as shown for purposes of illustration in the upper corner of the retarder tank 4, a sensor 11, for example, a sensor, is provided by the present invention. of ultrasonic level, to transmit to a control center or system 10 a signal corresponding to the level of the retarder in the reservoir 4. The level of the reservoir is detected after finishing the operations In the control center 10, it can be detected an abnormally small or large amount of retarder added by statistical comparison from the data accumulated by the control center, 10 and this may result, for example, in a report to the concrete jig in such a way that the abnormal level of retarder can be made known to the personnel in the concrete plant, or, as another example, in such a way that the spout 6 of the retarder tank 4 can be opened or closed under the circumstances. In addition, when an ultrasonic level sensor, shown for purposes. illustrative designated as 8 in. the upper right corner of the wash water tank 5, is provided, and when an ultrasonic concentration sensor 9 or the like is provided, as shown for illustrative purposes in the lower right corner of the wash water tank 5, the amount and The concentration of wash water can be detected by these sensors. This information obtained in this way can also be transferred to the control center. 10. From the amount and concentration of the wash water in the wash water tank 5, the amount of concrete to be kept active can be calculated. The data collected can be used to determine if there are relatively large or small amounts of retarder in the wash water, and problems can be avoided by having the control center report the abnormally large or small amounts of retarder to the particular concrete plant. , by having the control center open or close the dispenser to adjust the retarder jet accordingly, for example daily. The data can also be used to adjust additions of retarders - when the wash water is subsequently used to prepare fresh concrete. To ensure the accuracy of the quantity of. added retarder, it is preferable to employ a reducing sugar, for example glucose and test paper which indicates by color changes when the paper is immersed in the wash water, the presence and the relative amount of reducing sugar present in the wash water. Accordingly, exemplary method of the present invention comprises the detection of the amount of the retarder in the wash water by the addition of a reducing sugar to the retarder to further determine the activity of the concrete in the wash water. said reducing sugar. Additional exemplary methods comprise detecting the amount of retarder in the wash water by wetting with wash water from a test paper obtained by allowing a filter paper to adsorb a reagent to show a visually recognizable color reaction with. reducing sugar ... and drying the moistened filter paper. The reducing sugar is preferably glucose, dextrose, or mixture thereof; and the reagent preferably comprises glucose oxides, peroxides, o-toluidine, or mixtures thereof. An exemplary work mode of the present invention is described as follows. The term "apparatus" as used herein and below refers to a mixer truck, tank, or other container to which concrete has adhered (eg, ready-to-use, pre-mixed) and which requires a washing operation. Thus, the term apparatus may refer to the drum of a stirring vehicle (eg, a ready mix truck) or to mixing containers as used in the sites of concrete plants when fresh concrete is manufactured.
Furthermore, the term "retarder" coiao is used herein to refer to all compounds which have the effect of generally retarding the setting of the concrete, including hydroxycarboxylic acid compounds, for example gluconic acid, citric acid and tartaric acid; sugars, for example glucose, sucrose and lactose; aminophosphoric acid compounds and their salts, for example, aminotrimethylene phosphonic acid; water reducing agents of lignin sulphonic acids and salts thereof which do not have an accelerating action; as well as ~ silicofluorides The term "wash water" means _and refers to a suspension of concrete or cement that continues to have activity (for example that has some ability to harden or to harden further) .An exemplary mode of work of the method and system of the present invention, can be explained with reference to Figure 1 as follows: A stirring vehicle 1 (for example, a ready mix truck), which is only an example of the apparatus in which concrete is adhered, is washing with washing water from a washing water tank 2 containing the washing water temporarily, then, from this washing water, aggregates such as sand and / or gravel are removed / recovered using an aggregate separator 3, and the resulting wash water is recovered again in the temporary wash water tank 2. Thus, the washing water can be used repeatedly, here, when a suffix amount is added. As a retarder starting from retarder tank 4 to the concrete wash water, which is also the wash water, the wash water from the concrete can be used repeatedly in washing operations while continuing to keep the concrete activity gradually to increase the concentration of concrete in the wash water. When the wash water arrives at such a high concentration that it causes a drawback for washing, the wash water of concrete is transferred from temporary tank 2 to the tank 5, further diluted with fresh water, and add a retarder to allow further processing Thus, when the wash water reaches or exceeds a predetermined concentration, it is stored in a slag tank 5 at a concentration of 20% or less (by weight). The concrete is stored in the slab tank 5 in a concentrated state from day 1 until less than a week later, a slow stirring device is used to prevent the concrete from settling in. A retarder is added to the wash water tank. concrete 5 from the retarder tank 4 through a spout 6 in an appropriate amount The control of the appropriate quantity supplied is described below.
When used in the production of fresh concrete, the water in the concrete wash of the wash water tank 5 should preferably not be added so that the concrete that contributes to the concrete feed exceeds 3% (by weight). A concrete plant that produces a fresh concrete is designated at number 7 in Figure 1. Excessive concrete wash water that can not. be added to the concrete feed can be mixed with fresh concrete the next day or a day later. Therefore, some days, the entire amount of concrete wash water can be used and on other days only a part of the concrete wash water can be. used. After washing the last agitating vehicle - with washing water, the washing water is treated and transferred to a temporary wash water tank. 2 and transferred to lama deposit 5. In the lama tank 5, the appropriate amount of retarder to be added to the concentrated concrete wash water, for storage purposes, may be determined by persons with ordinary skill in the art and said amount will depend on seasonal influences, temperature, storage time, condensation, as well as other factors. According to the present invention, a sensor 8 for detecting the volume of the wash water of concrete and a concentration sensor 9 for detecting the concentration of wash water are provided in the lama tank 5. Signals from these sensors are transmitted to a control center 10 to allow calculation of the appropriate amount of the retarder to be added primarily. In addition, a sensor 11 for detecting the amount (eg, volume) of the retarder is provided in the retarder tank 4, and a signal therefrom is transmitted to a control center 10 such that the volume of retarder used and the volume of retarder after the completion of the daily washing operations can be "determined" In other words, the volume of the retarder used in a day together with the previous day's signal (and signals from previous days as well) can be detected. At control center 10, the data is collected and can be treated on a statistical basis, since the total amount and concentration of the wash water of concrete discharged from the operations of each day and the daily amount of the retarder used can be calculated. This capability allows a review as to whether the amount of retarder that is added has been excessive or insufficient, and in the control center 10 all the signals sensors can be detected. After a review of the data, when it is determined that the amount of retarder added is excessive or insufficient, the control center can report this result to the particular plant and / or transmit a signal to perform an additional operation such as opening or close the valve from the dispenser. Sensing devices suitable for use in the present invention, such as sensors for detecting fluid volume, are available. For example, there are - sensors that use reflection principles based on ultrasonic waves and the like. To detect concentration levels, sensors based on ultrasonic operation, specific gravity methods, electrical detection based on impedance variation, and the like are known. In addition, optical sensors are available to detect the concentration based on the detection of scattered light by colloidal systems. In addition, the communication system mentioned above which can be used for the communication of the sensors with the control center 10 can be any system that can achieve the objectives described above, include, for example, the NTT-DOPA network, a network telephone, Internet mode L -... (mobile phone) intranet, and other known means. In addition, the means to transmit signals from each plant is not limited. Preferably, the transmission device allows confirmation of the transmission and by the capacity of the control center 10 to send warnings to each plant, if necessary or required, according to the mode of the returned signals. In addition, for safety, it is preferred to add a reducing sugar having retarding properties, such as for example glucose, to the retarder to allow the determination of the amount of retarder. Thus, further exemplary methods of the present invention comprise the detection of the amount of retarder in the wash water of concrete by the addition of a reducing sugar to the retarder to visually recognize the concrete activity in the wash water of concrete by color reaction with said reducing sugar are contemplated. The detection reagent detects biochemically: hydrogen peroxide to be formed by the use of an enzyme such as glucose oxidase and galactose oxidase in the enzymatic method or detected by a chemical method. Above all, glucose forms hydrogen peroxide through the action of glucose oxidase, and then oxidizes o-toluidine by peroxidase to give a yellow blue color according to the glucose concentration. This reaction is sensitive, detectable in a short period of time, "and specific for glucose. - - In addition, there is Bertrand's method that consists of adding a Fehling solution to a liquid, of sample, and the titration of Cu20 that it is precipitated according to the amount of reducing sugar with H2SO4 or a standard solution of potassium permanganate. acid, the Soirtogyi method for titrant I2 CU2O having been produced by reducing CuS04 with a reducing sugar in alkalinity with KI03 + KI with Na2SÜ3 and allowing I2 provides a color with a starch solution and the like The visual recognition in the present invention refers to a method by which it can be judged with the naked eye without using a specific instrument. of which the presence of a reducing sugar can be determined with certainty is preferred, however, all the reactions accnied by a change are included. It can be recognized by the naked eye, such as the formation of turbidity, the increase in transparency and the change in the state of the surface. A method that allows to determine the presence of a reducing sugar by a color reaction or another change allowing a filter paper to previously adsorb a reagent, drying the resulting paper obtained, and immersing the paper prepared in this way in the wash water. concrete is preferred. In addition, a method cising the placement of sample water to be examined in a glass tube and adding a reagent to the water drop ¾ drop to determine some change is preferred. Exemplary concrete wash water reuse systems of the present invention therefore cise: a retarder jet 4 having a sensor 11 which operates to generate a signal corresponding to the retarder level in a retarder tank 4; and a concrete wash water tank 5 having a sensor 8 operating to generate a signal corresponding to the level of concrete wash water in the concrete wash water tank 5, the concrete wash water tank it also has a sensor 9 that operates to generate a signal corresponding to the concentration of lama .. in the concrete wash water contained in the concrete wash water tank 9. The signal can be fed to a control center , or in accordance with the aforementioned, a communication system that allows the sensors to communicate with a control center elsewhere in the place or that is in a totally different location. Also within the present invention it is contemplated that exemplary concrete wash water reuse systems may include numerous groups of reservoirs and sensors, located in different locations, operating to communicate when the same master center 10. The following examples are provided for illustrative purposes and are not intended to limit the scope of the invention. EXAMPLE 1 - A solution containing 20% sodium gluconate and 15% glucose was used as a retarder. In plant A, the amounts of retarder that are used daily from the first day of a month were 21, 18, 23, 0, 17, 19 and 93 liters, respectively. The day on which no retarder was added (0 liters) was a holiday. Since 93 liters represent an abnormal amount, this fact was reported to plant A, and the following morning the retarder was examined in the water tank of concrete 5 by immersing a test paper in the water. of concrete washing. The test paper was the paper obtained by impregnation of a filter paper with the mixed solution of 450 units of glucose oxidase, 14 units of peroxidase and 8.4 mg of o-toluidine, and drying the filter paper. resulting. The test paper turned, pure blue, and in this way the danger of sending concrete with the use of this concrete wash water for fresh concrete could be avoided as it is usual that it could not set. EXAMPLE 2 The amount of concrete wash water in the concrete wash water tank 5 in plant A was detected by a first sensor 8 and the lama concentration was detected by a concentration sensor 9. In addition, the amount of The retarder was detected by a second sensor 11. The retarder used was the same as that of Example 1. The amount of retarder used, the concentration of the wash water and the amount of concrete wash water that were detected in 12 days they are presented in Table 1. Table 1 _ _ Day Mon Mar Wed Thu Fri Sat Sun Mon Wed Wed Thu Fri
Retarder 17 20 41 18 15 20 0 16 21 22 25 14 used - (liters) Quantity 13 11 20 11 12 13 0? 5 17 12 14 17 of concrete wash water- Concen- 15 17 20 15 12 14 10. 12 16 17 20 concrete wash water supply (%) In plant A, the amount of retarder used per day is approximately 15 to 22 liters. On Friday, the third day, the amount of retarder used was a bit excessive, but the concentration and amount of concrete wash water were both extremely high this day. This predicts a large: amount of fresh concrete back (eg, ready-to-use mix) and the ready mixed concrete remaining, and therefore requires a large amount of retarder, and thus, the control center did not send out any warning. Without. However, on Friday, the last day in Table 1, despite the high concentration of concrete wash water, amount of retarder is relatively small. When the plank is left to rest, the concrete that loses its activity will be incorporated into fresh concrete the next morning. Obviously the quality of the products will be reduced. Accordingly, the control center sends a signal to open a jet 6 and close the jet 6 at. at a time when approximately 15 liters of the retarder were introduced and transmitted this instruction to plant A. The next morning, the test using the same test paper as in Example 1 was carried out and not ", no color reaction was observed and Finally, it was able to preserve the activity of the concrete, thus, in operations that include washing with water containing a device retarder, for example a mixing drum, in which or on which concrete it is adhered, the removal of aggregates from the concrete. washing water, and the reuse of concrete wash water as part of a mixing water for a fresh batch of concrete the next day after operations or after the next day of operations, the present invention offers numerous benefits such as, for example, example, avoid the discharge of waste from the concrete plant, minimize the use of overdoses or sub-doses of retarders in the wash water. concrete, allow detection of retarder dosing levels after operations and allow operators to instantly handle dosing problems; avoid the hazards of making a fresh concrete with concrete wash water that has excessive or insufficient levels of retarder; and make concrete with deactivated concrete; therefore, the present invention offers numerous benefits and avoids the dangers and drawbacks of prior art practices.