JP5392893B2 - Production method of ready-mixed concrete - Google Patents

Description

The present invention relates to a method for producing ready-mixed concrete by measuring and kneading various concrete materials such as gravel, sand, cement, water, and an admixture.

  The ready-mixed concrete production plant temporarily stores concrete materials such as gravel, sand, cement, water, and admixture in a material storage tank arranged in the upper part of the plant, and each measuring tank arranged in the lower layer based on a shipping request. A predetermined amount of various materials are weighed and after weighing, the discharge gates at the bottom of each weighing tank are sequentially opened, various materials are put into a lower mixer, and kneaded for a predetermined time to produce ready-mixed concrete. At this time, in order to improve the mixing condition of the materials in the mixer, the materials are not charged all at once, but first, sand, cement and water are introduced first, and gravel is mixed therein. It is common.

However, if materials are sequentially added at regular time intervals, it will take a certain amount of time for material introduction, and this kind of plant is always required to produce high-quality products quickly. In the concrete manufacturing plant of Patent Document 1 (Japanese Patent Laid-Open No. 2000-61928), a premix chute formed in a funnel shape gradually tapering from the upper opening toward the lower opening between the weighing tank and the mixer in the horizontal direction. Distributing the sand and gravel at almost the same time and allowing them to flow down along the inner wall of the rotating premix chute, and throwing them into the mixer while premixing reduces the kneading time in the mixer. To increase manufacturing capacity.
JP 2000-61928 A

  In the above plant, sand and gravel are discharged into the rotating premix chute and poured into the mixer while flowing down along the inner wall of the premix chute, so that appropriate premixing can be performed and kneading time can be shortened. However, it is desired to increase the production capacity by further improvement.

Problem that the present invention has been made in view of the above problems, to shorten the kneading time by performing premixed before introduction into the mixer more efficiently, provides a method for producing ready-mixed concrete, which can improve the production capacity And

Substantially in order to solve the above problems, in the method for producing ready-mixed concrete according to the present invention, between the measuring tank and the lower mixer various concrete materials, as progressively tapered toward from the upper opening to the lower opening A premix chute formed in a funnel shape is rotatably arranged in a horizontal direction by a drive motor, and premixed while discharging measured sand and gravel almost simultaneously and flowing down along the inner wall of the premix chute. Te method of manufacturing a raw concrete so as to put into the mixer, to allow shifting the driving motor for rotating the premix chute, sand at birth concrete production, high speed premix shot to put the initial gravel By increasing the centrifugal force, the sand and gravel are pressed against the inner wall of the premix chute to spread the sand and gravel alternately in layers and throw Switch the premix chute to low speed rotation after a predetermined time from the start to weaken the centrifugal force, and let the sand and gravel formed in layers flow down along the inner wall of the premix chute and throw it into the mixer while premixing It is characterized by being introduced into

According to the manufacturing method of the ready-mixed concrete according to the present invention, to allow shifting the driving motor for rotating the premix chute, sand, in the turned initial gravel increase the centrifugal force by high speed rotation of the premix chute sand Then, gravel is pressed against the inner wall of the premix chute, and the sand and gravel are alternately layered, and after a predetermined time has elapsed from the start of charging, the premix chute is switched to low speed rotation to weaken the centrifugal force and the layered sand , since the gravel by flowing down along the inner wall of the premix chute to put into the mixer with premixed, premixed sand and gravel are more effectively performed, shortening of the kneading time in the mixer This is possible and can improve the production capacity.

In the method for producing ready-mixed concrete according to the present invention, a premix chute formed in a substantially funnel shape gradually taper from the upper opening toward the lower opening between the sand and gravel measuring tank and the mixer. A motor is disposed so as to be rotatable in the horizontal direction. The drive motor for rotating the premix chute can be changed by, for example, an inverter, and the premix chute is rotated at a high speed at the beginning of charging of sand and gravel. Set to switch to rotation.

  When the premix chute rotates at high speed, the thrown sand and gravel are pressed against the inner wall of the premix chute by centrifugal force, while when rotating at low speed, the centrifugal force is weakened and clumped to the inner wall of the premix chute. The number of rotations of the premix chute is set as appropriate so that the sand and gravel fall. The number of rotations depends on the diameter of the premix chute, etc., but may be set to, for example, about 36 rotations / minute during high speed rotation and about 18 rotations / minute during low speed rotation. Further, the switching timing of the premix chute from the high speed rotation to the low speed rotation is set to a high speed rotation at the start of the addition of sand and gravel, and if the time for inputting sand and gravel is about 12 to 15 seconds, for example, 1/3 to 1 thereof. It is preferable to switch from high-speed rotation to low-speed rotation after a time of about / 2.

  In order to perform preliminary mixing with the premix chute, sand and gravel are discharged almost simultaneously toward the inner wall of the premix chute while rotating the premix chute at a high speed. When sand is released toward the inner wall of the premix chute that rotates at high speed, the sand flows down along the inner wall of the premix chute, and a predetermined amount of the sand is pressed against the inner wall of the premix chute by centrifugal force and sticks to the premix chute. A sand layer clinging to the inner wall is formed. Since the premix chute is rotating, when the formed sand layer reaches the gravel discharge site, the gravel falls toward the sand layer, and a predetermined amount of gravel is pressed onto the sand layer by centrifugal force. It sticks and a gravel layer is formed on the sand layer. Therefore, if the premix chute rotates several times, several layers in which sand and gravel are alternately overlapped are formed.

  And when the premix chute is switched to low-speed rotation after a predetermined time has elapsed since the sand and gravel is added, the inner wall of the premix chute where the centrifugal force acting on the sand and gravel is weakened and the sand and gravel rotate in layers The sand and gravel are further mixed and fed into the lower mixer.

  In this way, the centrifugal force of the rotating premix chute is used to spread sand and gravel on the inner wall of the premix chute so that they are alternately layered and then put into the mixer at once. The previous preliminary mixing is effectively performed, the kneading time in the mixer can be shortened, and the production capacity can be improved.

  Embodiments of the present invention will be described below with reference to the drawings.

  Reference numeral 1 in the figure denotes a ready-mixed concrete manufacturing plant that stores, measures, and kneads various concrete materials to manufacture ready-mixed concrete. A mixer block 3, a measuring tank block 4, and a storage tank block 5 are provided on a base frame 2. The receiving chamber blocks 6 are stacked in a hierarchical manner.

  In the receiving room block 6 on the top floor, gravel and sand supplied by the inclined conveyor 7 from the above-mentioned aggregate yard are distributed by the distribution chute 8 and are distributed to the storage tank 9 of the lower storage tank block 5 for each type. It has been thrown. The storage tank block 5 includes gravel and sand storage tanks 9 as well as cement, water and admixture storage tanks.

  The measuring tank block 4 includes a gravel measuring tank 10, a sand measuring tank 11, and a cement measuring tank 12, and also includes a measuring tank (not shown) for water and an admixture. Further, the mixer block 3 is provided with a mixer 13 for producing ready-mixed concrete by kneading the concrete material discharged from each of the measuring tanks, and a concrete hopper 14 for temporarily storing ready-mixed discharged concrete below the mixer 13. It has.

  Between each said measuring tank and the mixer 13, the premix chute 15 which pre-mixes the gravel discharged | emitted from a measuring tank, sand, and cement is provided, This premix chute 15 is shown in FIG. , Having an upper opening 16 and a lower opening 17 and having a substantially funnel shape tapered from the upper opening 16 toward the lower opening 17 and having a cylindrical body 18 with the lower opening 17 opened at the lower end thereof. . Further, a cement discharge pipe 19 for guiding the cement discharged from the cement metering tank 12 is arranged in the central portion of the premix chute 15, and the cement is discharged to the central portion of gravel and sand falling in the premix chute 15. Premixed.

  In order to rotate the premix chute 15, a circular rail 20 is disposed so as to surround the vicinity of the upper portion of the premix chute 15, while a flange 21 is fixed to the outer periphery of the upper portion of the premix chute 15. The wheels 22 are arranged in the four directions, and the wheels 22 are placed on the circular rail 20 so that the premix chute 15 is rotatable along the circular rail 20.

  For rotation of the premix chute 15, a driving roller 24 attached to the driving motor 23 is brought into contact with a rubber tire 25 disposed along the periphery of the flange 21, and the premix chute 15 is horizontally driven by driving the driving motor 23. Rotate in the direction.

  The drive motor 23 that rotates the premix chute 15 can be shifted by a rotation speed controller 26 such as an inverter. The rotational speed of the premix chute 15 by the drive motor 23 is such that the sand and gravel that are thrown in are pressed against the inner wall of the premix chute 15 by centrifugal force during high speed rotation, and the centrifugal force is weakened during low speed rotation. Thus, the rotation speed is such that the sand and gravel stuck to the inner wall of the premix chute 15 are dropped.

  The number of rotations depends on the diameter of the premix chute 15, but for example, it is preferable to set the high speed rotation to about 36 rotations / minute and the low speed rotation to about 18 rotations / minute. Then, as shown in FIG. 4, the premix chute 15 is rotated at a high speed at the start of almost simultaneous addition of sand and gravel, and is switched to a low speed rotation after a predetermined time has elapsed. For example, if the sand and gravel charging time is about 12 seconds, it may be set to switch from high-speed rotation to low-speed rotation after about 1/3 to 1/2 time has elapsed.

  When mixing ready-mixed concrete with the mixer 13 of the ready-mixed concrete production plant 1 having the above-described configuration, first, a predetermined amount is measured in the gravel measuring tank 10, the sand measuring tank 11, and the cement measuring tank 12, and also mixed with water and water. A predetermined amount of the agent is also weighed. Subsequently, as shown in the material input time chart of FIG. 4, each material is input. At this time, paying attention to the sand and gravel, the sand and gravel are thrown into the premix chute 15 almost at the same time, and at this time, the premix chute 15 is kept at high speed.

  When sand is released toward the inner wall of the premix chute 15 that rotates at high speed, the sand flows down along the inner wall of the premix chute 15, and a predetermined amount of the sand is pressed against the inner wall of the premix chute 15 by centrifugal force and sticks. A sand layer sticking to the inner wall of the premix chute 15 is formed. Since the premix chute 15 is rotating, the gravel falls toward the sand layer when the formed sand layer reaches the gravel input location, and a predetermined amount of gravel is pressed onto the sand layer by centrifugal force. As a result, the gravel layer is formed on the sand layer. Accordingly, as shown in FIG. 5, a sand / gravel layer A in which sand and gravel alternately overlap is formed on the inner wall of the premix chute 15 as shown in FIG.

  And when predetermined time passes from the start of addition of sand and gravel, the premix chute 15 is switched to low speed rotation. When the rotation speed is low, the centrifugal force is weakened, and sand and gravel sticking to the inner wall of the premix chute 15 start to fall, and the sand and gravel are further mixed and fed into the mixer 13. At this time, if cement is input, the cement is mixed with sand and gravel so as to wrap the cement, and the preliminary mixing before charging to the mixer 13 is sufficiently performed.

  In this way, the rotation of the premix chute 15 can be changed, and the sand and gravel are set by switching to the high speed rotation at the beginning of the sand and gravel input and switching to the low speed rotation after a predetermined time. Then, sand and gravel whose centrifugal force was increased by high-speed rotation was pressed against the inner wall of the premix chute 15 and dispersed into several layers, and then the layer of sand and gravel formed at once was switched to low-speed rotation. Dispensing to the mixer 13 facilitates premixing of sand and gravel before charging into the mixer 13, shortening the kneading time in the mixer 13 and improving the production capacity.

It is a schematic explanatory drawing of the ready-mixed concrete manufacturing plant which enforces the manufacturing method of ready- mixed concrete concerning this invention. It is a principal part enlarged view of FIG. It is the top view which abbreviate | omitted a part of FIG. It is a time chart regarding material input in the Example of the manufacturing method of the ready-mixed concrete concerning this invention. It is a figure explaining the sticking condition of the sand and gravel to a premix chute.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Ready-mixed concrete production plant 2 ... Stand 3 ... Mixer block 4 ... Measuring tank block 5 ... Storage tank block 6 ... Receiving room block 10 ... Gravel measuring tank 11 ... Sand measuring tank 12 ... Cement measuring tank 15 ... Premix chute 19 ... Cement discharge pipe 20 ... Rail 21 ... Flange 22 ... Wheel 23 ... Drive motor 24 ... Drive roller 25 ... Rubber tire

Claims (1)

Between the measuring tank of various concrete materials and the lower mixer, a premix chute formed in a substantially funnel shape gradually tapering from the upper opening toward the lower opening is disposed so as to be rotatable in the horizontal direction by a driving motor, In a method for producing ready-mixed concrete , in which measured sand and gravel are discharged almost simultaneously and pre-mixed while flowing down along the inner wall of the premix chute, the premix chute is rotated. The drive motor can be shifted, and sand and gravel during the production of ready-mixed concrete are rotated at a high speed by rotating the premix chute at high speed to increase the centrifugal force and press the sand and gravel against the inner wall of the premix chute to remove sand and gravel. Alternately stir in layers, switch the premix chute to low speed rotation after a predetermined time from the start of charging, and apply centrifugal force. Because, method for producing ready-mixed concrete, characterized in that so as to sand in layers, with gravel caused to flow down along the inner wall of the premix chute turned to put the premixed with the mixer.

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