JPH03120015A - Humidistat - Google Patents

Abstract

PURPOSE:To contrive the quality control of artificial sand and the prevention of environmental pollution by providing a rotating shaft and a drum with one or more screws, by sprinkling water over crushed sand through a sprinkling nozzle provided at the rotating shaft and kneading the crushed sand through a lifter, and by causing the crushed sand to pass through a metal gauze to obtain a desired crushed sand. CONSTITUTION:When a humidistat 13 is charged with a dried crushed sand, from which a fine powder has been removed via dry grinding, screening and dry classifying processes, the crushed sand goes into a drum 107 by the rotation-driving force of a feeding screw 104a to be supplied with water from an injection nozzle while being further kneaded by a crossfeed screw 104b, and reaches a drum intermediate part. In the drum intermediate part, a lifter 105 rotates together with the drum 107 and the supplied water is uniformly distributed in the crushed powder. Thus, the crushed powder is conditioned in humidity, soon reaches a metal gauze part 108 on the drum outlet side, passes through the metal gauze 108 and is delivered to a depot by a transportation means such as belt conveyor. On the other hand, broken particles and foreign matters incapable of passing through the metal gauze 108 are excluded via a separate foreign matter discharging chute 110. In this manner, the quality of the crushed sand is stabilized and an environmental pollution such as scattering of fine powder decreases.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a humidity control device in a plant for manufacturing artificial sand used in concrete, etc., and is particularly effective in controlling the quality of manufactured artificial sand and preventing environmental pollution. Concerning the effective humidifier.

[Conventional technology]

Conventionally, artificial sand such as crushed sand produced by a dry method using a crusher or the like has been exported and stored in a dry state from a crushed sand manufacturing plant. Therefore, since crushed sand is a mixture of particles with a particle size of 5 mm or less in an appropriate ratio, that is, it is close to natural sand, when it is stored in a storage tank or on a flat surface outdoors, or when it is piled up from a high place, Large particles tend to flow farther away from the point of fall, while smaller particles tend to accumulate relatively closer to the point of fall.

As a result, during the crushing stage, sand that had an ideally uniform particle size distribution becomes uneven, and by the time it is used, the sand has a particle size distribution that is not what was desired for use in concrete. It was causing inconvenience.

In addition, when falling from a height or during transportation, natural wind generates dust, which sometimes causes environmental pollution.

Furthermore, when the sand is exposed to the sun outdoors, it becomes extremely dry, and as a result, the amount of water increases during the production and kneading of ready-mixed concrete, and the water-cement ratio tends to increase. In other words, the very fine dry powder adhering to the surface of sand grains absorbs water during the mixing process of fresh concrete, resulting in an increase in the apparent amount of water, and as a result, the water-cement ratio increases and cement The amount increased, making it uneconomical.

[Problems to be Solved by the Invention] As described above, when producing crushed sand using a dry process, when crushed sand falls from a high place during transportation or storage,
Crushed sand, which had an overall uniform particle size distribution, becomes uneven and separates into large and small particles, making it impossible to provide crushed sand with the particle size distribution required for ready-mixed concrete. .

Therefore, it has been strongly required to avoid these uneven grain and separation phenomena.

There is also a strong desire to prevent contamination of the working environment due to dust scattering caused by falling from a height or during outdoor transportation.

Furthermore, no effective measures have been found to prevent the phenomenon of increased water-to-cement ratio due to water absorption during mixing of ready-mixed concrete by dried fine powder.

[Means to solve the problem]

In order to solve the above-mentioned problems, the humidity control device of the present invention is a device that controls the humidity of crushed sand that has been dry crushed and sieved through dry classification to remove fine particles. Drums are fixedly installed concentrically, a single or double thread screw is provided on the rotating shaft on the raw material charging side and the drum, and a rotary joint is connected to one end of the rotating shaft to provide a water supply source. A water spray nozzle was provided on the rotating shaft of the screw part, a plurality of lifters were provided inside the center of the drum, and a wire mesh was provided around the entire circumference of the drum on the raw material discharge side.

[For production]

When the dried crushed sand from which fine powder has been removed through the steps of dry crushing, sieving, and dry classification is charged into the humidity controller of the present invention,
The water enters the drum due to the rotational thrust of the feed screw, is further kneaded by the transverse feed screw, and is supplied with water from the injection nozzle to reach the middle part of the drum. A lifter is located in the middle of the drum and rotates with the drum, and this raking action distributes the supplied water evenly into the crushed sand and controls the humidity.
Eventually, it reaches the wire mesh section on the drum discharge side, passes through this wire mesh, and is delivered to a storage location by means of transportation such as a belt conveyor. On the other hand, crushed grains and foreign matter larger than the wire mesh (for example, dust, lumps formed from stone powder) that cannot pass through the wire mesh are removed via a separate foreign matter discharge chute.

(Example) Details of an example according to the present invention will be described below based on the drawings.

1 to 3 show an embodiment according to the present invention, FIG. 1 is an overall side sectional view, FIG. 2 is a cross sectional view taken from FIG. This is a flow sheet for a crushed sand production plant that includes a humidifier.

To explain the flow of a crushed sand manufacturing plant based on Fig. 3, raw material (crushed stone) is put into a service hopper 1, cut out in a fixed amount from a cutting feeder 2, fed into a crushed sand crusher 4 by a belt conveyor 3, and crushed. Ru. Thereafter, it is fed into a vibrating sieve 6 by a conveyor 5 and is sieved. The materials on the net are returned to the conveyor 3 and crushed by the sand crusher 4.

The material under the screen is fed into the air separator 8 by the belt conveyor 7, and unnecessary fine powder (0, 0,
Stone powder (less than 15 mm) is removed and stored in a dust tank (fine stone powder storage tank) 12 via a screw conveyor 10 and a packet elevator 11. On the other hand, the crushed sand from which fine powder has been removed by air classification enters the humidity controller 13, where it is adjusted to an appropriate moisture content, that is, 3 to 5% of the weight of crushed sand, and is deposited and stored via the belt conveyor 9. .

Next, the structure and operation of an embodiment of the humidity conditioner of the present invention will be explained based on FIGS. 1 and 2.

The raw material (crushed sand) from which fine powder has been removed by the air separator 8 is fed into the feed chute 101, and the hollow rotating shaft 1
The water is moved to the water sprinkling section A inside the drum 7 by the feeding screw 104a attached to the drum 7.

101a is an inspection hole. Drum 107 is spoke 10
6 and the reinforcing member 107a, and is fixed concentrically with the rotating shaft 102, and rotates integrally with the rotating shaft 102. The rotating shaft 106 is supported at both ends in bearings 103, 103 mounted on a pedestal 111, 111, and is supported by a chain wheel 115.
It is driven and rotated by an electric motor (not shown) via. drum 1
The raw material that has entered into the interior of
Water supply valve 1 connected to one end of 2 via rotary joint 112
13, water is added to the drum 107 from the water spray nozzle 114, and the mixture is repeatedly lifted up and dropped by six lifters fixed to the inner surface of the drum of the kneading section B in the middle of the drum 107, and kneaded. Then, the water is made into a state having a uniform moisture content, and is further conveyed to the discharge side. In the discharge section C, a wire mesh 108 is stretched around the entire surface of the drum, and the crushed raw material sand whose humidity has been adjusted in the kneading section B is passed through the wire mesh 10.
8 and is conveyed by a subsequent belt conveyor 9 via a receiving chute 109. On the other hand, crushed stones, dust, and foreign matter larger than the wire mesh of 10 days are discharged via a foreign matter discharge chute 110 provided at the edge of the drum 107.

As described above, crushed sand is transported and stored with a uniform moisture content (3 to 5%) by the humidity controller of the present invention.
Even when falling from a high place, it is given appropriate adhesion by moisture, so tin powder phenomenon is less likely to occur, and since fine powder has been removed in advance, environmental pollution due to scattering does not occur.

〔Effect of the invention〕

The humidity control device of the present invention is a device that controls humidity after dry crushing, sieving, and dry classification to remove fine powder, and includes a drum fixed concentrically to a hollow rotating shaft via spokes. , the rotary shaft and drum are equipped with a single thread or double thread screw, water is sprinkled with a water nozzle provided on the rotating shaft, kneaded with a lifter, and crushed sand is obtained by passing through a wire mesh, so that the amount of adhering water is 3. With a uniform humidity control of ~5%,
Since it is used in the production of ready-mixed concrete, it can provide ready-mixed concrete of stable quality and good quality.

In addition, during transportation and storage processes after the humidity conditioner, environmental pollution such as tin powder and fine powder scattering is less likely to occur, which is advantageous in terms of maintenance.

In addition, as a result of uniform and proper humidity control, even the fine powder adhering to the surface of crushed sand absorbs water appropriately, making it possible to keep the water-cement ratio low during ready-mixed concrete production, reducing the amount of cement used. Economic efficiency improves.

[Brief Description of the Drawings] Figures 1 to 3 show embodiments of the present invention, in which Figure 1 is an overall side sectional view, Figure 2 is a cross sectional view taken from Figure 1 FIG. 3 is a flow sheet (process system diagram) of a crushed sand production plant including the humidity controller of the present invention. 1... Service hopper, 2... Cutting feeder, 3
... Belt conveyor, 4... Sand crusher, 5.
... Conveyor, 6... Vibrating sieve, 7... Belt conveyor, 8... Air separator, 9... Belt conveyor, 10... Belt conveyor, 11... Packet elevator, 12... Dust tank, 13...Humidity conditioner,
101... Infeed chute, 102... Rotating shaft, 10
3...Bearing, 104a...Feeding screw, 104b
...Transverse feed screw, 105...Lifter, 106.
... Spoke, 107 ... Drum, 108 ... Wire mesh, 109 ... Receiving chute, 110 ... Foreign matter discharge chute, 111 ... Frame, 112 ... Rotating joint,
113... Water supply valve, 114... Water nozzle, 115
...Chain wheel, 116...Safety cover, A.
...Water spraying section, B...Kneading section, C...Discharge section.

Claims (1)

[Claims] (1) This is a device for dry crushing and sifting crushed sand to remove fine particles by dry classification, and then controlling the humidity. A drum is fixed concentrically to a hollow rotating shaft via spokes, and raw materials are charged. A single or double thread screw is provided on the rotating shaft and the drum, a rotary joint is connected to one end of the rotating shaft to provide a water supply source, and a water nozzle is provided on the rotating shaft of the screw part, and the drum A humidity control machine, comprising: a plurality of lifters arranged inside the central part of the drum; and a wire mesh provided around the entire circumference of the drum on the raw material discharge side.