JPS60187354A - Apparatus for preparing desalted sand - Google Patents

Abstract

PURPOSE:To prepare desalted sand contg. less salt than regulated for fine aggregate for concrete and having almost uniform water content continuously from sea sand by charging sea sand to a rotary dehydrator and scattering pure water at the inlet of the dehydrator. CONSTITUTION:The device is constituted of a cylindrical rotary dehydrator 1 provided with a porous filter to its peripheral wall, a receiving hopper 2 for supplying sand contg. salt such as sea sand to the dehydrator 1 and a conveyor belt 4 for transporting the sand, a receiving device 5 for receiving the desalted sand from the dehydrator 1. An annular falling preventing plate 12 for sand surrounding the inlet side of the dehydrator over a necessary width is provided to the feeding side of the dehydrator 1, and a water spraying pipe 13 for desalting is provided over an appropriate range in the direction of transportation of the sand in the dehydrator. By this apparatus, desalted sand having less salt content than regulated for fine aggregate for concrete and having almost a uniform water content is prepared continuously.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to an apparatus for producing desalinated sand mainly used as fine aggregate for concrete materials, and in particular, to The present invention relates to a device that reduces slump variation during concrete production and efficiently removes salt from fine aggregate used in reinforced concrete.

(Prior art) Concrete is durable, water resistant, and easy to form, and by combining it with reinforcing steel, it compensates for some of the shortcomings of concrete and expands its range of use, making it suitable for major commercial projects.
We are solidifying our position using l14 as a material.

As is well known, concrete is made by hardening aggregates such as sand or gravel with cement paste, and as a result, demand for sand as an essential material is increasing, and there is a gradual shortage of suitable sand. However, due to recent aggregate conditions, the use of sea sand has been widely attempted.

However, sea sand contains salt as a component, and the removal of this has been posed as a major issue in construction.

In other words, when using such sand, the Architectural Institute of Japan stipulates that the standard value for salt content in fine aggregate is 0.04% or less when converted to Na06.
On the other hand, the Japan Society of Civil Engineers states that fine aggregate of 0.1% or less must be used.

Normally, the salinity of seawater is generally considered to be 8%, but the salinity of sea sand is approximately proportional to the amount of seawater attached to it, and s = o, oap (S is the salt content of sea sand ( P is the water content of the sea sand. ) Therefore, as mentioned above, in order to reduce the salt content in sea sand, it is important to first drain the adhering seawater.

Therefore, the open piling method is used to remove salt from conventional methods.

Methods such as watering on land, sprinkling or pouring water onboard a collection vessel, and using a sand washing machine have been used, but all of these methods require vast areas or use water in a prolific manner. It has many drawbacks, such as the long time it takes to remove salt, and it has not yet reached a level of practical satisfaction.

Therefore, recently, with the aim of improving this, we have been cleaning such sea sand,
Regarding salt removal, Japanese Unexamined Patent Publication No. 115-24509 was published, and an improved method using an n-rotating drum was proposed.

(Problems that /i&) tries to solve) However, this method attempts to improve the way the sand and cleaning water come into contact in the rotating drum, and the rotation speed of the rotating drum also increases.
The amount of p and m is small, and it is no more than cleaning by using a large amount of water.

Moreover, the product sand that is taken out from the right end of the drum after washing the sea sand is in the form of a slurry, so if it is placed in an aggregate storage area such as a ready-mixed concrete + WE factory, it will have a high water content and the surface water of the product sand will migrate from the top to the bottom. Because the moisture content varies greatly, if this type of cotton is used to make ready-mixed concrete, the slump during mixing of the ready-mixed concrete will be large, making it difficult to produce ready-mixed concrete of stable quality.

Therefore, the manufactured sand cannot be used immediately, and there is an inconvenience that the sand must be piled up in the open and washed to lower the moisture content before use.

This first work is a quick response to the above-mentioned situation.We solved the above problems and used desalinated sand, which has a salt content below the standard value and an approximately average moisture content, as a concrete fine aggregate, rather than sea sand. The purpose is to provide an efficient manufacturing device that can produce the same.

(Means for resolving gap 1) The features of this guide to solving gap 14 above and achieving its purpose are summarized in the accompanying drawings, particularly in Figure 1. , a cylindrical rotary dehydrator (1) is installed on the entire circumferential wall of the porous filter, and sea sand is poured into the rotary dehydrator (1). A receiving hopper (2) and a conveyor belt (4) for supplying and conveying sand containing salt;
It consists of a receiving device for receiving the sand desalinated by the rotary dewatering machine, such as a receiving hopper (5) and a conveyor belt (7), and has an inlet opening on the supply side of the rotary dewatering machine (1). It has an annular fall prevention plate (to) surrounding the required width, and a desalination water sprinkling pipe (to).
) is provided over an appropriate length in the direction of hardness transfer within the dehydrator.

(effect) The operation of the apparatus having the above structure will be described below.

Now, the rotary dehydrator (1) is driven in the above device, and the sea sand is conveyed through the conveyor belt (4) to the rotary dewaterer (1).
When the sea sand is fed into the rotary dehydrator (1), the sea sand is shaken and dehydrated in the rotary dehydrator (1). Due to the centrifugal force caused by the related rotation of several hundred r, p, and m, it is propelled spirally along the inner wall of the horizontal copper, and as it moves toward the exit side,
During this time, the water contained in the sea sand is removed by the centrifugal force being applied to the surrounding wall, the water content in the sea sand is lowered and kept constant, and the salt contained therein is removed.

At this time, a drop-off prevention plate (b) is provided around the rotary dehydrator side to regulate the supply company into the dewatering +a (1) and to prevent sea sand from falling to the side. The difference in wall height due to the shielding on the population side by the falling prevention plate (b) and the substantial opening on the rotary dehydrator outlet side is the result of the dehydrator (
1) A forward thrust is added to the eight lines of sea sand, allowing for a smooth transition of the sea sand.

At the same time, seawater is applied to a suitable length of the dehydrator through the sprinkling pipe (131) to substantially reduce the salt content in the sea sand, thereby achieving a desalination effect through dehydration.

Therefore, without using a large amount of water as in the past, the desalination time can be shortened by the shaking-off action of centrifugal force, and continuous desalination treatment can be performed by continuously supplying sea sand. .

(Example) Hereinafter, an example of the present tyjl will be described in more detail with reference to the accompanying drawings.

Fig. 1 and Fig. 8 show 1 flll of this γ4 manufacturing equipment,
A rotary dehydrator (with sea sand fqJ on the supply side with the water in the middle)
@Salt-containing sand (hereinafter referred to as sea sand) is supplied and conveyed from the hopper (2) to the rotary dehydrator (1) via the bottom gate (3) of the receiving hopper (2) that stores the salt-containing sand. A conveyor belt (4) for transporting the sand is provided on the outlet side, and a receiving device for receiving the desalted sand, in the illustrated example a receiving hopper (5), and a receiving hopper. The bottom gate (6) of (5) is connected to a desalted sand drawer conveyor belt (7) for receiving and taking out the desalted sand.

Of these, the rotary dehydrator (1) forms the dense part of this book te)), and its details are as shown in section aFyJ. (9)
It is composed of a WN wall that is sandwiched between the WN wall and the WN wall is integrally formed with an additional pole (II), and on the sea sand supply side, the WN wall is closed in an annular shape over the required length of the periphery of the entrance opening. A falling-off prevention plate (to) is attached, and the opposite outlet side is essentially an open cotton.

The filter member (10) made of a net-like material is usually a wire mesh, and a material that does not corrode due to salt is particularly preferable, and a synthetic resin mesh or even a normal fabric can also be used.

The size of the mesh is appropriately selected depending on the degree of sieving of the sea sand.

In addition, on the supply side opening side of the rotary dehydrator (1), there is a desalination watering pipe for sprinkling fresh water onto the supplied sea sand, in case it is not possible to remove salt below the standard value by centrifugal dehydration alone. are disposed within the dehydrator (1) over an appropriate length range. As this watering pipe, a pipe having a large number of normal watering holes is used.

In addition, the rotary dehydrator (1) is equipped with a mechanism for rotational drive as shown in Figs. A pair of bearings 0η(17) , (17) (17) are arranged around the bearings 0η (17) at appropriate intervals and placed on the floor stand 05) at the bottom of the horizontal copper.
(16)
(A pair of wheels fixed to both ends of 165), (9)
), (i, and m are fitted together so that they can frictionally rotate with each other.

Of the shafts α6) + Q'), at least the 10,000 shafts 7) (16) are connected to the shaft (rotation) via a drive motor (to the belt) installed on the floor stand). ) rotates with the boe attached to the
Therefore, the wheel fixed at both ends (H), - is @
The rotary dehydrator (1) is mounted on a circular guide tray as a polar rotating wheel.When one drive is performed, the other wheel -9- supports the dehydrator (1) as a driven wheel.

In addition, in the figure, (21) is a cover to prevent splashing water during sea sand dewatering treatment.

In addition, in order to further stabilize the spiral movement of sea sand along the inner wall of the dehydrator (1), a guide plate or guide groove is provided in the inner wall of the dehydrator (1) in a spiral manner. It is also a suitable bite pattern to design it so that it moves along the hook.

In addition, the explanation using the illustrated example above is based on the rotary dehydrator (1) being placed horizontally.
Although the case has been described above, the rotary dehydrator may be installed vertically or obliquely, and may be moved from the upper or lower side to the lower or upper side, and desalination may be performed between the two.

<Effect of If-4) As mentioned above, books are put into the sea sand full-rotation dehydrator in the harvesting process 1d, and the salt is removed by boiling them in the form of seawater instead of turning them into a slurry. Salt contained in sea sand can be efficiently and continuously removed without using large amounts of water, making it possible to remove salt from conventional IJ removal methods.
It is possible to significantly shorten the J time, and it is also easy to control the moisture content to a constant moisture content, making it possible to make sand that is extremely suitable as an aggregate for concrete manufacturing materials. Yes, this improves the quality of concreteff
: Not only can it further increase durability, but it also has various effects such as reducing slump variation during concrete production.

In addition, according to Kamishi, the fresh water provided, together with the spiral movement of sea sand, promotes desalination, and the centrifugal dewatering inside the rotary dehydrator greatly contributes to shortening the desalination time. Historically, it is expected that a remarkable effect will be achieved by configuring equipment as a whole according to the treatment and controlling the rotation speed etc. to improve the economic efficiency of centrifugal dewatering.

In particular, in this IQ-IMIf K, the difference in height between the shielding of the population side by the rotation prevention plate and the substantially open exit side causes the sea sand to move inside the rotary dehydrator to be propelled. It promotes the action and exhibits favorable effects as a dehydration and desalination device.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram showing one example of the salt dispersing device of the present invention, Fig. 2 is a side view of the same, Fig. 3 is a partially enlarged view of the rotary dehydrator which constitutes the main part, and Fig. 4 is a drive machine FIG. (1)...Rotating dehydrator, (2)...Receiving hopper. (4)...Supply conveyor belt. (5)...Reception hopper. (6)...Drawer conveyor belt. 00)...filter, 02)...drop-off prevention plate. (111O...Water pipe for desalination.

Claims (1)

[Claims] 1. A cylindrical rotary dehydrator in which a porous filter is arranged on the peripheral wall, a receiving hopper and a conveyor belt for supplying and conveying salt-containing sand such as sea sand into the rotary dehydrator, and the rotary dehydrator. The rotary dewatering machine includes a receiving device for receiving desalinated sand, and the rotary dehydrator has an annular drop-off prevention plate surrounding the artificial opening over a required width on the supply side, and a desalination water sprinkling device. 1. A desalting sand manufacturing device, characterized in that a pipe is provided over an appropriate length in the sand transfer direction within the dehydrator.