Agitator car cleaning method and cleaning water for agitator car

Abstract

To provide a washing method of an agitator car capable of washing effectively ready mixed concrete in a drum type container.SOLUTION: A washing method of an agitator car having a drum type container for storing ready mixed concrete, includes a washing step for washing the drum type container by supplying washing water into the drum type container. The washing water is constituted of calcareous water.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a method for cleaning an agitator vehicle that transports ready-mixed concrete, and to cleaning water for the agitator vehicle used in the cleaning method. [Background technology]

[0002] Agitator vehicles that transport ready-mixed concrete are equipped with a drum-shaped container for storing the ready-mixed concrete. In such agitator vehicles, after the ready-mixed concrete is discharged from the drum-shaped container, the ready-mixed concrete remaining in the drum-shaped container needs to be washed before it hardens. One method for washing the ready-mixed concrete remaining in the drum-shaped container is to supply tap water or the like into the drum-shaped container, as described in Patent Document 1. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2002-541005 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the above-described cleaning method is unable to effectively clean the ready-mixed concrete in the drum-type container, and therefore a more effective cleaning method is required.

[0005] Therefore, an object of the present invention is to provide a method for cleaning an agitator vehicle that can effectively clean ready-mixed concrete in a drum-shaped container, and cleaning water for the agitator vehicle. [Means for solving the problem]

[0006] The method for cleaning an agitator vehicle according to the present invention is a method for cleaning an agitator vehicle equipped with a drum-shaped container for storing ready-mixed concrete, and includes a cleaning step of supplying cleaning water into the drum-shaped container to clean the drum-shaped container, the cleaning water being composed of carbonated water.

[0007] The carbonated water may have a carbon dioxide concentration of 0.2 g / l to 1.7 g / l.

[0008] The cleaning process may include a supply process for supplying carbonated water into the drum-shaped container, and at least one of an agitation cleaning process for agitating the carbonated water in the drum-shaped container, and a static cleaning process for leaving the carbonated water in the drum-shaped container static without agitating it.

[0009] In the cleaning step, carbonated water may be supplied to the drum-shaped container so that the volume of the carbonated water in the drum-shaped container is 12% or more of the volume of the drum-shaped container.

[0010] The method for cleaning an agitator vehicle according to the present invention may further include a discharge step of discharging the mixed water of carbonated water and ready-mixed concrete from inside the drum-shaped container, and the discharge step may be carried out in parallel with the cleaning step or after the cleaning step.

[0011] The cleaning water for an agitator wheel according to the present invention is cleaning water supplied to a drum-shaped container in the above-described method for cleaning an agitator wheel, and is composed of carbonated water.

[0012] The washing water for the agitator vehicle may have a carbon dioxide concentration of 0.2 g / l to 1.7 g / l. [Effects of the Invention]

[0013] As described above, according to the present invention, the ready-mixed concrete in the drum-shaped container can be effectively washed. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a schematic diagram showing an outline of an agitator wheel to be cleaned by a cleaning method for an agitator wheel according to a first embodiment of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the following drawings, the same or corresponding parts are designated by the same reference characters, and description thereof will not be repeated.

[0016] As shown in FIG. 1, the method for cleaning an agitator vehicle according to this embodiment involves cleaning an agitator vehicle 10 equipped with a drum-shaped container 1 that contains ready-mixed concrete. The drum-shaped container 1 is capable of agitating the ready-mixed concrete contained therein. Specifically, the drum-shaped container 1 is equipped with an agitation device (for example, a spiral agitation blade or the like) (not shown) inside the drum-shaped container 1 that agitates the ready-mixed concrete. The drum-shaped container 1 is also rotatable about an axis L. This allows the drum-shaped container 1 to agitate the ready-mixed concrete contained therein by rotating. The volume of the drum-shaped container 1 is not particularly limited, and may be, for example, 2.5 m 3 ~10m 3 may be 6m 3 ~10m 3 may be.

[0017] Ready-mixed concrete has fluidity. Ready-mixed concrete may be formed by mixing at least coarse aggregate, fine aggregate, and water, or may be formed by mixing at least fine aggregate and water but not including coarse aggregate (so-called mortar).

[0018] The cement is not particularly limited, and various commercially available cements can be used. Specific examples of cement include various Portland cements such as ordinary Portland cement and high-early-strength Portland cement, as well as various blended cements such as blast-furnace cement, silica cement, and fly ash cement. Other examples of cement include white Portland cement and alumina cement. Still other examples of cement include ultra-rapid-hardening cements such as calcium aluminate, calcium sulfoaluminate, and calcium fluoroaluminate. The cement may be one of the above cements, or a mixture of two or more of them.

[0019] Coarse aggregate can be used in a size such that 85% by mass or more of the aggregate does not pass through a 5 mm sieve. Specific examples of coarse aggregate include crushed sandstone, pebbles (river gravel), natural lightweight coarse aggregate (perlite, vermiculite, etc.), by-product lightweight coarse aggregate, artificial lightweight coarse aggregate, and recycled aggregate. The amount of coarse aggregate used relative to the cement is not particularly limited, and may be, for example, 180% by mass to 210% by mass, or 190% by mass to 200% by mass.

[0020] Fine aggregate can be used in a size that passes all 10 mm sieve openings and 85% by mass or more of the aggregate passes a 5 mm sieve opening. Specific examples of fine aggregate include natural sand such as mountain sand, river sand, land sand, and sea sand, as well as crushed sand (more specifically, crushed limestone sand) formed by artificially crushing sandstone, limestone, etc. The amount of fine aggregate used relative to the cement is not particularly limited, and may be, for example, 100% by mass to 300% by mass, or 150% by mass to 250% by mass.

[0021] The sizes of the coarse aggregate and fine aggregate mentioned above are measured by the sieve test method for aggregates in accordance with JIS A 1102, and represent the test sieve openings of JIS Z 8801-1.

[0022] Furthermore, other materials contained in ready-mixed concrete are not particularly limited, and examples thereof include fibrous materials (glass fibers, steel fibers, vinylon fibers, aramid fibers, polypropylene fibers, carbon fibers, etc.), admixtures (blast furnace slag, fly ash, silica fume, expansive agents, etc.), and admixtures (water-reducing agents, thickeners, antifoaming agents, etc.).

[0023] The water is not particularly limited, and for example, ordinary tap water can be used. The water may also contain, for example, admixtures such as water-reducing agents used when kneading mortar or concrete, polymer dispersion liquids, shrinkage-reducing agents, setting modifiers, etc.

[0024] The agitator wheel washing method according to this embodiment includes a washing step of supplying washing water into the drum-shaped container 1 to wash the drum-shaped container 1. The washing water (agitator wheel washing water) used in the washing step is composed of carbonated water. The carbon dioxide concentration of the carbonated water (carbon dioxide concentration when supplied to the drum-shaped container 1) is not particularly limited, and is preferably 0.2 g / L to 1.7 g / L, and more preferably 0.9 g / L to 1.7 g / L, for example. The carbon dioxide concentration of the carbonated water can be measured by the method described in the Examples below. The washing step is preferably performed by supplying carbonated water (agitator wheel washing water) to the drum-shaped container 1 so that the volume of the carbonated water in the drum-shaped container 1 (hereinafter also referred to as the "amount of carbonated water in the drum") is preferably 12% or more, more preferably 35% or more, relative to the volume of the drum-shaped container 1. The amount of carbonated water in the drum may be 25% or more, or may be 70% or more, of the maximum amount of ready-mixed concrete that can be accommodated in the drum-shaped container 1 (maximum load capacity).

[0025] Methods for producing carbonated water include, but are not limited to, injecting carbon dioxide into tap water, groundwater, and recycled water from ready-mix concrete manufacturing plants. Recycled water is obtained by removing coarse and fine aggregates from wastewater generated during the cleaning of facilities containing ready-mix concrete. Recycled water may contain calcium hydroxide eluted from cement and have a relatively high alkalinity (specifically, a pH of 10 to 12). Recycled water may be sludge water containing solids such as cement, or supernatant water obtained by removing solids from sludge water. Examples of carbon dioxide used to produce carbonated water include commercially available carbon dioxide and carbon dioxide contained in gases generated in facilities (e.g., boiler facilities) in various factories (e.g., cement factories, ready-mix concrete factories, concrete product manufacturing factories, etc.). Carbonated water is preferably produced immediately before the supply process described below.

[0026] The cleaning process also includes a supplying process for supplying carbonated water (cleaning water for agitator cars) into the drum-shaped container 1. The cleaning process also includes at least one of an agitation cleaning process for agitating the carbonated water (cleaning water for agitator cars) in the drum-shaped container 1, and a static cleaning process for leaving the carbonated water in the drum-shaped container static without agitating it.

[0027] The supplying step can be performed by supplying carbonated water (washing water for the agitator wheel) from a hopper 2 provided in the agitator wheel 10 into the drum-shaped container 1. In the supplying step, it is preferable to supply carbonated water (washing water for the agitator wheel) into the drum-shaped container 1 so that the amount of carbonated water in the drum falls within the above-mentioned range.

[0028] The agitation and cleaning process can be performed by rotating the drum-shaped container 1. The agitation and cleaning process is preferably performed when the amount of carbonated water in the drum is within the above-mentioned range. The duration of the agitation and cleaning process is not particularly limited and may be, for example, 30 to 120 seconds, or 30 to 60 seconds. The agitation and cleaning process is preferably performed by visually inspecting the interior of the drum-shaped container 1 to determine whether to terminate or continue the process by checking the state of fresh concrete adhesion inside (e.g., whether there is no adhesion). The agitation and cleaning process may be performed in parallel with the supplying process or after the supplying process. The rotation of the drum-shaped container 1 in the cleaning process may involve rotating the drum-shaped container 1 in one direction around the axis L one or more times, or may involve rotating the drum-shaped container 1 in one direction by a predetermined angle less than 360°. The rotation of the drum-shaped container 1 may alternate between rotating in one direction and rotating in the opposite direction.

[0029] The static cleaning step can be performed by not rotating the drum-type container 1 for a predetermined time. The static cleaning step is preferably performed when the amount of carbonated water in the drum is within the above-mentioned range. The time for performing the static cleaning step is not particularly limited and may be, for example, 30 to 180 seconds, or may be 30 to 90 seconds. It is preferable to visually inspect the interior of the drum-type container 1 to determine whether to terminate or continue the static cleaning step by checking the state of fresh concrete adhesion inside (e.g., whether there is no adhesion). The static cleaning step may be performed in parallel with the supplying step or after the supplying step. It is also preferable to perform the static cleaning step multiple times. Specifically, after the first static cleaning step, the drum-type container 1 may be rotated by an angle less than 360° (e.g., 45° or 180°), and then the static cleaning step may be performed again. In other words, it is preferable to perform the static cleaning step multiple times so that the carbonated water in the drum-type container 1 comes into contact with a different region inside the drum-type container 1 each time the static cleaning step is performed.

[0030] In the washing step, either the stirring washing step or the stationary washing step may be performed only once, or the stirring washing step and the stationary washing step may be performed alternately one or more times. Examples of the case where the stirring washing step and the stationary washing step are performed alternately include a case where the stirring washing step is first performed and then the stationary washing step is performed, and a case where the stationary washing step is first performed and then the stirring washing step is performed, etc.

[0031] The agitator wheel cleaning method according to this embodiment may include a discharge step of discharging a mixture of carbonated water (agitator wheel cleaning water) and ready-mixed concrete from inside the drum-shaped container 1. The discharge step can be carried out via a chute 3 provided in the agitator wheel 10. The discharge step may be carried out after the cleaning step, or in parallel with the cleaning step. Examples of cases in which the discharge step is carried out in parallel with the cleaning step include a case in which the discharge step is carried out while an agitation cleaning step or a static cleaning step is carried out after the supply step, or a case in which the discharge step is carried out while the supply step and an agitation cleaning step or a static cleaning step are carried out. Furthermore, when the discharge step is carried out in parallel with the cleaning step, it is preferable that the cleaning step be carried out while maintaining the amount of carbonated water in the drum within the above range.

[0032] As described above, the agitator vehicle cleaning method and cleaning water for an agitator vehicle according to this embodiment can effectively clean ready-mixed concrete in a drum-shaped container.

[0033] That is, by providing a cleaning step in which carbonated water is supplied as cleaning water into the drum-shaped container 1 to clean the drum-shaped container 1, the ready-mixed concrete in the drum-shaped container 1 can be effectively cleaned.

[0034] Furthermore, by setting the carbon dioxide concentration of the carbonated water within the above range, the ready-mixed concrete in the drum-shaped container 1 can be washed more effectively.

[0035] Furthermore, by providing at least one of an agitation cleaning process in which the carbonated water in the drum-shaped container 1 is agitated and a static cleaning process in which the carbonated water in the drum-shaped container 1 is allowed to stand without agitation, the ready-mixed concrete in the drum-shaped container 1 can be washed more effectively. Specifically, when the agitation cleaning process is performed, a relatively large number of carbon dioxide bubbles are generated in the carbonated water. Therefore, the action of these bubbles makes it easier for the ready-mixed concrete adhering to the inside of the drum-shaped container 1 to peel off from the drum-shaped container 1. This allows the ready-mixed concrete in the drum-shaped container 1 to be washed more effectively. Furthermore, when the static cleaning process is performed, a relatively long contact time with the carbonated water can be ensured at a predetermined location of the drum-shaped container 1. Therefore, the action of the carbonated water (washing water for an agitator vehicle) makes it easier for the ready-mixed concrete adhering to the inside of the drum-shaped container 1 to peel off from the drum-shaped container 1. This allows the ready-mixed concrete in the drum-shaped container 1 to be washed more effectively.

[0036] In addition, by supplying carbonated water to the drum-shaped container 1 so that the volume of the carbonated water in the drum-shaped container 1 is in the above-mentioned ratio to the volume of the drum-shaped container 1, the fresh concrete in the drum-shaped container 1 can be washed more effectively.

[0037] The agitator wheel cleaning method and agitator wheel cleaning water according to the present invention are not limited to the above-described embodiments, and various modifications are possible without departing from the spirit of the present invention. Furthermore, the configurations, methods, etc. of the above-described multiple embodiments may be arbitrarily adopted and combined (the configurations, methods, etc. of one embodiment may be applied to the configurations, methods, etc. of other embodiments), and further, it goes without saying that the configurations, methods, etc. of various other modified examples may be arbitrarily selected and adopted in the configurations, methods, etc. of the above-described embodiments.

[0038] For example, in the above embodiment, the drum-shaped container 1 is provided with an agitator (for example, a spiral agitator blade) inside, but is not limited to this, and may not be provided with an agitator.

[0039] Furthermore, in the above embodiment, the drum-shaped container 1 is rotatable, but is not limited to this, and may be, for example, non-rotatable.

[0040] Furthermore, in the above embodiment, the supplying step is performed by supplying carbonated water (washing water for agitator cars) from the hopper 2 into the drum-shaped container 1, but this is not limited to this. Furthermore, in the above embodiment, the discharging step is performed via the chute 3, but this is not limited to this. For example, if the drum-shaped container 1 has an opening (not shown) that opens the storage space for ready-mixed concrete to the outside, the supplying step may be performed by supplying carbonated water into the drum-shaped container 1 from this opening. Furthermore, the discharging step may be performed by discharging a mixture of carbonated water (washing water for agitator cars) and ready-mixed concrete from this opening. [Example]

[0041] Examples of the present invention will be described below, but the present invention is not limited to the following examples.

[0042] <Mortar materials> Cement: Ordinary Portland cement (manufactured by Sumitomo Osaka Cement Co., Ltd.) Fine aggregate: land sand from Kakegawa, Shizuoka Prefecture Thickener: Marporose M-4000 (Matsumoto Oil & Fat Co., Ltd.) Water: Tap water <Cleaning water> Water: Tap water Simulated recovered water: supernatant water (pH 11) from wastewater used to wash mixers and laboratory equipment used to produce ready-mix concrete Carbonated water 1: Made by blowing carbon dioxide into tap water. Carbonated water 2: Made by blowing carbon dioxide into simulated recovered water.

[0043] <Preparation of mortar samples> Mortar samples were prepared according to the composition shown in Table 1 below.

[0044] [Table 1]

[0045] <Confirming the effectiveness of static cleaning> (1) 600 g of the above mortar sample was placed in a 1000 ml plastic container, and the container was shaken up and down 20 times to adhere the mortar sample to the inner surface of the container. (2) Then, the mortar sample that was not attached to the container was removed. (3) Then, the amount of mortar sample adhered (adhesion amount A before cleaning) was calculated from the difference between the mass of the container before the mortar sample adhered and the mass of the container after the mortar sample adhered. (4) Washing water was poured into the container with the mortar sample attached so that it filled the container, and the container was left to stand for 60 seconds (static washing step). (5) After the static washing step, the mixed water of the washing water and the mortar sample was discharged from the container (discharging step). (6) The amount of mortar sample attached (post-washing amount B) was calculated from the difference between the mass of the container before the mortar sample was attached and the mass of the container after the discharging process. The removal rate was calculated using the following formula (1). The carbon dioxide concentration of the carbonated water, the pre-washing amount A, the post-washing amount B, and the removal rate are shown in Table 2 below. The carbon dioxide concentration of the carbonated water was calculated by converting the amount of inorganic carbon to the amount of CO2 using a TOC meter manufactured by Shimadzu Corporation. Removal rate (%) = 1 - (amount of adhesion after cleaning B / amount of adhesion before cleaning A) × 100 (1)

[0046] <Confirmation of agitation cleaning effect> (1) 600 g of the above mortar sample was placed in a 1000 ml plastic container, and the container was shaken up and down 20 times to adhere the mortar sample to the inner surface of the container. (2) Then, the mortar sample that was not attached to the container was removed. (3) Then, the amount of mortar sample adhered (adhesion amount A before cleaning) was calculated from the difference between the mass of the container before the mortar sample adhered and the mass of the container after the mortar sample adhered. (4) 500 ml of cleaning water was poured into the container with the mortar sample attached, and the cleaning water was stirred by shaking it up and down a specified number of times (3, 5, or 10 times) (stirring and cleaning process). (5) After the stirring and washing step, the mixed water of the washing water and the mortar sample was discharged from the container (discharge step). (6) The amount of mortar sample adhered (adhesion amount B after washing) was calculated from the difference between the mass of the container before the mortar sample adhered and the mass of the container after the discharging process. The removal rate was calculated using the above formula (1). The carbon dioxide concentration of carbonated water, the adhesion amount A before washing, the adhesion amount B after washing, and the removal rate are shown in Table 2 below.

[0047] [Table 2]

[0048] <Summary> Looking at Table 2 above, it can be seen that in static cleaning, the removal rate is higher in each Example than in each Comparative Example. Also, in agitation cleaning, when comparing each Example with each Comparative Example with the same number of shakings, it can be seen that each Example has a higher removal rate. In other words, when cleaning an agitator car, as in the present invention, by supplying carbonated water to a drum-shaped container, the ready-mixed concrete in the drum-shaped container can be effectively cleaned. [Explanation of symbols]

[0049] 1... drum-type container, 2... hopper, 3... chute, 10... agitator wheel, L... axis

Claims

1. A method for cleaning an agitator vehicle equipped with a drum-shaped container for storing ready-mixed concrete, comprising: The method includes a cleaning step of supplying cleaning water into the drum-shaped container to clean the drum-shaped container, The wash water consists of carbonated water, Carbonated water has a carbon dioxide concentration of 0.2 g / l to 1.7 g / l. How to clean an agitator car.

2. The cleaning step includes a supply step of supplying carbonated water into the drum-shaped container, and at least one of an agitation cleaning step of agitating the carbonated water in the drum-shaped container and a static cleaning step of leaving the carbonated water in the drum-shaped container static without agitating it.

2. The method for cleaning an agitator wheel according to claim 1.

3. In the cleaning step, carbonated water is supplied to the drum-shaped container so that the volume of the carbonated water in the drum-shaped container is 12% or more of the volume of the drum-shaped container.

3. The method for cleaning an agitator wheel according to claim 1 or 2.

4. The method further includes a discharge step of discharging the mixed water of carbonated water and ready-mixed concrete from the drum-shaped container, The discharge step is carried out in parallel with or after the cleaning step. The method for cleaning an agitator wheel according to any one of claims 1 to 3.

5. The cleaning water supplied to the drum-shaped container in the cleaning method for the agitator wheel according to any one of claims 1 to 4, It consists of carbonated water, The carbon dioxide concentration is 0.2 g / l to 1.7 g / l; Cleaning water for agitator vehicles.

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