JPS6272581A - Concrete cooling device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a concrete cooling device that is used to properly finish the construction of hot concrete or mass concrete.

(Prior art and its problems) When concrete is manufactured during hot weather, the mixing temperature increases, the amount of water required to obtain the same consistency increases, and the amount of cement required to achieve the same water-cement ratio also increases. do. In addition, the slump of concrete during hot weather during transport increases, and the unit water and cement suspension must be further increased. This is not only uneconomical, but also increases the II rise due to the heat generation of cement.
Drying shrinkage also increases, making it more likely that defects such as cracks will occur. Furthermore, it hardens more quickly, which reduces the time allowed for pouring and makes construction difficult.

In addition, in mass concrete, since concrete is a poor conductor of heat, the internal temperature rises as it hardens and generates heat, and the temperature difference between the inside and outside surface becomes large, making surface cracks more likely to occur. Become. Furthermore, if the concrete is restrained from the outside, the shrinkage caused by the temperature drop after hardening is restrained, resulting in large tensile stress.

For these reasons, for hot concrete and mass concrete, some measure is needed to lower the temperature of the concrete during II, and it is necessary to suppress the temperature rise due to heat generated by the hydration reaction of cement as much as possible.

Conventionally, concrete mixing a! In order to keep the temperature low, methods were used such as cooling materials such as cement and aggregate with cold water, or adding ice to the concrete mixing water.

Another method has been to install a cooling pipe at the concrete pouring site and run cold water through the pipe during and immediately after pouring concrete to lower the internal temperature of the concrete.

However, methods such as cooling materials such as cement and aggregate with cold water, or cooling concrete immediately after pouring with cold water, do not have a cooling effect, although they require large-scale cooling equipment to obtain cold water. It is not large and it is difficult to control the quality of the concrete. Furthermore, the method of cooling mixing water with ice requires large-scale ice-making equipment, and it is difficult to appropriately control the temperature and moisture content of concrete. In any case, the conventional method requires large-scale equipment, has poor workability, and does not have a very large cooling effect.

(Objective of the Invention) This invention was made in view of the above-mentioned conventional problems, and its purpose is to provide a system that requires relatively simple equipment, has high work efficiency, and can cool concrete efficiently. The goal is to provide equipment.

(Structure of the Invention) The cooling device of the present invention cools concrete using the latent heat and sensible heat of liquefied gas, and includes an insulating housing made of a heat insulating material and a cooling device that penetrates through the inside of the insulating housing. The concrete transport pipe is provided with a concrete transport pipe, a liquefied gas supply route for introducing liquefied gas into the inside of the heat insulating housing, and an exhaust route for leading out the gas inside the heat insulating housing.

(Embodiment) FIG. 1 shows a first embodiment of a cooling device according to the present invention. In the figure, 10 is a heat insulating housing made of a heat insulating material, and 12 is a concrete transport pipe disposed through the inside of the heat insulating housing 10. Insulated housing 1
A liquefied gas supply port 14 is formed at the bottom right side of the 0, and a supply pipe 16 equipped with a solenoid valve 18 is connected thereto. Further, an exhaust port 22 is formed in the upper left side of the heat insulating housing 10, and an exhaust pipe 24 equipped with a solenoid valve 26 is connected to the exhaust port 22.

Reference numeral 20 denotes a temperature sensor placed inside the right end side of the concrete transport pipe 12, which detects the temperature of the concrete being fed through the pipe 12. The output of temperature sensor 20 is used to control solenoid valve 18 as described below.

A pressure sensor 28 is attached to the exhaust pipe 24 and detects the gas pressure inside the heat insulating housing 10.

The output of the pressure sensor 28 is used to control the solenoid valve 26 as described later.

As the liquefied gas used for cooling, liquid nitrogen is suitable because it is easily available and easy to handle. A cylinder of liquid nitrogen is connected to the supply pipe 16, and the electromagnetic valve 18 is appropriately opened to introduce liquid nitrogen into the heat insulating housing 10 as indicated by arrow C.

The liquid nitrogen fed into the heat insulating housing 10 is vaporized and fills the inside of the housing 10. Then, the solenoid valve 26 is opened as appropriate to lead out the nitrogen gas inside the housing 10 to the outside.

On the other hand, a concrete pump is connected to the left end side of the concrete transport pipe 12, and concrete to be cooled is fed into the transport pipe 12 as indicated by arrow A. The concrete that has been sent flows out from the right end side of the transport pipe 12 in the direction of arrow B and is guided to the concrete placement site. The space inside the heat insulating housing 10 is filled with liquid nitrogen, and its latent heat and sensible heat keep the interior at an extremely low temperature. Transport pipe 12
passes through this housing 10, so the transport pipe 1
The concrete flowing through 2 is also rapidly cooled. The temperature of the concrete is measured by a temperature sensor 2 installed on the downstream side of the transport pipe 12.
The opening degree of the electromagnetic valve 18 is adjusted so that this detected temperature becomes the set value, and if the concrete temperature is high, more liquid nitrogen is supplied into the housing 10. The gas pressure inside the housing 10 is detected by a pressure sensor 28, and the opening degree of the solenoid valve 26 is adjusted based on the output of the pressure sensor 28 so that the internal pressure does not exceed a set value. emit.

FIG. 2 shows a second embodiment of the invention.

The difference from the first embodiment is that the concrete transport pipe 12 passing through the heat insulating housing 10 is arranged in a spirally bent manner. In this way, the total length of the transport pipe 12 within the housing 10 becomes longer, and even if the external shape of the device is relatively small, the length of the pipe 12 passing through the cold space can be increased.

FIG. 3 shows a third embodiment of the invention.

In this embodiment, the insulating housing 10 is of elongated design, and the concrete transport pipe 12 is centered on a vertical axis! It is wound in a spiral shape. Concrete is pumped from the lower end of the transport pipe 12 as shown by arrow A, and cooled concrete flows out from the upper end of the transport pipe 12 as shown by arrow B.

Further, in the third embodiment, J3 has a supply pipe 1 equipped with a solenoid valve 18 at a supply port 14 provided at the lower part of the heat insulating housing 10.
6 are connected, liquid nitrogen is supplied from there as shown by arrow C, and an appropriate amount of liquid nitrogen is stored in the housing 10 in a liquid state. The upper space within the housing 10 is filled with vaporized nitrogen gas. This nitrogen gas is
Exhaust port 22. Exhaust piping 24. Solenoid valve 2
6 and is released as shown by the arrow.

The solenoid valve 26 is controlled based on the output of a pressure sensor 28 that detects the external pressure within the housing 10.

Further, a level sensor 30 is disposed on the inner side wall of the housing 10, and is used to detect the storage level of liquid nitrogen. The solenoid valve 18 is controlled based on the output of the level sensor 30 so that the stored amount of liquid nitrogen detected by the level sensor 30 becomes a set value.

In the third embodiment, since a considerable portion of the concrete transport pipe 12 is immersed in liquid nitrogen, the cooling effect on the concrete is extremely large, and the concrete can be cooled to an extremely low temperature in a short period of time.

FIG. 4 (A>(B)) shows an application example of the cooling device of the present invention. In (8), three heat insulating housings 1
0a, 10b, and 10c are lined up in a straight line, their respective concrete transport pipes 12 are connected in a straight line, concrete is supplied from one end of the connected pipes as shown by arrow A, and the concrete flows out as shown by arrow B. In addition, a solenoid valve 18 is connected to the liquefied gas supply port 14 of the heat insulating housing 10C.
The supply piping 16 having a
An exhaust pipe 24 equipped with a solenoid valve 26 is connected to the exhaust port 22 of the exhaust port 22 . Then, the exhaust port 22 of the heat insulation housing 10C and the supply port 14 of the heat insulation housing 10b are directly connected, and the exhaust port 22 of the heat insulation housing 10b and the supply port 14 of the heat insulation housing 10a are directly connected.
It is directly connected to the supply port 14 of. When liquefied gas is supplied from the supply pipe 16 as shown by arrow C, the vaporized gas sequentially flows from the heat insulating housing 10c to 10b to 10a and is exhausted as shown by the arrow. Concrete transport pipes 12 pass through these housings, and the concrete transported therethrough is cooled by the latent heat and heat of the liquefied gas. The solenoid valves 18 and 26 are controlled by the first. This is the same as the second embodiment.

The implementation example of FIG. 4(B) is also substantially the same as (A>). In this example, there are three insulating housings 10a.

10b and 1oe are arranged in parallel in the vertical direction, and the respective concrete transport pipes 12 are connected in series using the connecting pipe 32, and the liquefied gas supply spaces are connected, and the liquefied gas is sent to the lowermost insulating housing 10c. , the gas is discharged from the uppermost heat insulating housing 10a.

Furthermore, according to the present invention, the following application device can also be constructed. The concrete is pre-cooled using the embodiment shown in FIG. 2, and the concrete is further cooled using the embodiment shown in FIG. That is, the right end of the transport pipe 12 of the apparatus shown in FIG. 2 is connected to the lower end of the transport pipe 12 of the apparatus shown in FIG. Further, since the gas exhausted from the exhaust pipe 24 of the apparatus shown in FIG. 3 has a considerably high pressure and low temperature, this exhaust pipe 24 is connected to the supply pipe 16 of the apparatus shown in FIG. The liquefied gas from the cylinder and the liquefied gas discharged from the apparatus shown in FIG. 3 are mixed and supplied to the heat insulating housing 10 of the apparatus shown in FIG.

(Effects of the Invention) As explained in detail hereinafter, the concrete cooling device according to the present invention is a relatively simple device mainly consisting of a structure in which a concrete transport pipe is arranged through a heat insulating housing. For example, concrete can be cooled by combining it with a cylinder of liquid nitrogen. Therefore, the equipment is relatively compact and the equipment cost is low. Furthermore, the cooling effect is very good because it utilizes the latent heat and sensible heat of the liquefied gas, and the concrete can be efficiently and effectively cooled. Therefore, hot concrete and mass concrete construction can be finished well with simple work. In particular, in this invention, the gas discharged from the heat insulating housing can be easily recovered, so it is recompressed and liquefied.
It can also be republished for cooling purposes, in which case the running cost i can be significantly reduced.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of a first embodiment of the device according to the present invention, and FIG.
FIG. 3 is a block diagram of the apparatus of the second embodiment, FIG. 3 is a block diagram of the apparatus of the third embodiment, and FIGS. 4(A) and 4(B) are block diagrams showing application examples of the present invention.

Claims (3)

[Claims] (1) a heat insulating housing made of a heat insulating material, a concrete transport pipe disposed through the heat insulating housing, and a liquefied gas supply path for introducing liquefied gas into the heat insulating housing; A concrete cooling device comprising: an exhaust path for extracting the gas inside the heat insulating housing. (2) A temperature sensor for detecting the temperature of the concrete inside is provided on the downstream side of the concrete transport pipe, and a solenoid valve that is controlled according to the output of the temperature sensor is provided in the liquefied gas supply path. A concrete cooling device according to claim 1, characterized in that: (3) A pressure sensor for detecting gas pressure within the heat insulating housing is provided, and an electromagnetic valve controlled in accordance with the output of the pressure sensor is provided in the exhaust path. A concrete cooling device according to claim 1.