JPS5843999Y2 - Laitance continuous drying equipment - Google Patents

Description

[Detailed explanation of the invention] This invention is designed to remove shallow slag from cocrete washing water discharged from ready-mixed concrete plants and secondary concrete product plants.
That is, it relates to an apparatus for continuously drying and pulverizing laitance.

In each of the above-mentioned plants, laitance is unavoidably generated, but in the past, all of this laitance was treated as industrial waste.

When processing, the laitance must be dried to a certain extent1.
The next treatment is carried out within the plant, and the subsequent secondary and tertiary treatment is outsourced to a pollution treatment company, or some of it is backfilled at the site where gravel was extracted. Even if this is not the case, transportation costs to the gravel extraction site will be required, and in either case, a considerable economic burden will be incurred.

By the way, this laitance contains a large amount of CaO (calcium oxide), which is highly effective in improving acidic soil, similar to magnesia lime, which is currently used as an acidic soil improving agent.

Therefore, if this laitance is completely dried and used as a soil improvement material, it will not only be possible to meet the demand for resource conservation in terms of effective use of waste, but at the same time it will be possible to finalize the laitance treatment, and it will be possible to properly dispose of the laitance. We should be able to expect the effect of killing two birds with one stone.

However, in order to commercialize laitance as a soil improvement material as described above, it is necessary to go through processes such as dehydration and drying, and it goes without saying that these processes are greatly influenced by the physical properties and chemical composition of the material.

In view of the above, this idea was made with the aim of effectively utilizing laitance and providing an optimal device for completely drying it. A feeding device that continuously supplies a fixed amount of laitance into a fluidized drying oven by an extruder via an intermediate storage tank, a fluidized drying oven that dries the supplied laitance while flowing it with hot air through a fluidizing medium, and drying from the drying oven. a separation device that continuously extracts laitance together with a fluidized medium and separates the two using a vibrating sieve; a discharge device that delivers the fluidized medium from the separation device into a drying oven and the dried laitance into a storage tank; This continuous laitance drying device includes a dust collector that collects floating laitance in a drying oven using a cyclone.

Next, this invention will be explained in detail based on the illustrated embodiment.Laitance is first precipitated in an existing thickener (not shown), and then subjected to dehydration treatment in an existing vacuum dehydrator (not shown). After that, it is transferred from a belt press 1 attached to a vacuum dehydrator to an intermediate storage tank 3 via a bucket loader 2.

At this time, the moisture content of Laitance after dehydration treatment is 45-5
It is 0%.

The intermediate storage tank 3 is located above the fluidized drying furnace 4 and is equipped with an agitator 5 for stirring the laitance.

A lower ore feeding device 6 equipped with a slide cage, a manual pinch valve, and a rotating chute is attached below the intermediate storage tank 3, and laitance is discharged downward from this lower ore feeding device 6 and sent to an extruder by a mono pump 7. 8, and then continuously fed in a fixed amount to the lower part of the fluidized drying oven 4 by this extruder 8.

The fluidized drying furnace 4 is filled with silica sand as a fluidized medium, and this fluidized medium is configured to form a fluidized bed in the furnace by hot air sent from below by a fluidizing blower 9.

Therefore, the laitance supplied into the furnace by the extruder 8 comes into contact with this high-temperature hot air and the fluidized medium while flowing, and as a result, the moisture evaporates instantaneously and is almost completely dried, while at the same time the water-containing bone is removed. The rapid expansion causes the shape to change from solid to powder.

On the other hand, one end of a discharge screw feeder 10 is fixed on the peripheral wall of the fluidized drying furnace 4 on the side opposite to the extruder 8, and the drying laitance is continuously supplied with the silica sand as the fluidized medium by this screw feeder 10. Fluidized drying oven 4
It is extracted from inside and sent to a vibrating sieve 11 installed below the other end of the discharge screw feeder 10.

After being separated from the silica sand as a fluid medium by this vibrating sieve 11, the dry laitance is introduced into a product storage hopper 14 via a roll crusher 13 by a packet elevator 12 connected to the vibrating sieve 11, where it is cooled. Waiting for the remaining steps such as bagging and weighing.

Reference numeral 15 indicates a weighing machine provided below a discharge screw feeder 16 provided at the lower end of the product storage hopper 14 for bagging.

The silica sand as a fluidized medium separated from the drying laitance by the vibrating sieve 11 is fed into the fluidized drying furnace 4 again by a packet elevator 17 for recovering silica sand, which is also connected to the vibrating sieve 11.

Reference numeral 18 denotes a cyclone installed above the product storage hopper 14. Its inlet is connected to the exhaust port 20 at the top of the fluidized fluidized drying oven 4 through one exhaust duct, and its outlet is connected to the exhaust port 20 at the top of the fluidized fluidized drying furnace 4 through an exhaust duct 21. They are connected to wet scrubbers 22, respectively.

Therefore, the floating laitance discharged from the exhaust port 20 of the fluidized drying oven 4 together with hot air is collected by this cyclone 18 and collected from the bottom into the product storage hopper 14, and the fine particles of floating laitance that have passed through the cyclone 18 are Thereafter, the floating laitance is collected by a wet scrubber 22 to prevent the floating laitance from being directly discharged into the outside air.

In addition, in the figure, 23 is a dust collection blower, and 24 is an exhaust duct 21.
25 indicates a dust collection duct that communicates with the control panel.

This invention has the above-mentioned structure, and since the dehydrated laitance is completely dried as described above, the drying of the laitance can be carried out continuously in an integrated process from weighing to bagging. Therefore, subsequent secondary and tertiary treatment of laitance is not necessary, and when laitance is used as a soil improvement material, it can be directly sprayed on the soil.

In addition, by using the fluidized drying oven 4 as a device for drying laitance, when drying laitance, it can be simultaneously pulverized and changed into a form suitable for spraying. No special equipment is required.

Furthermore, since a cyclone 18 and a wet scriber 22 are installed in the exhaust passage from the fluidized fluidized drying furnace 4, not only can floating laitance be collected and recovered by the cyclone 18, but also the laitance can be discharged into the outside air. This can be reliably prevented, and the risk of causing pollution can be completely eliminated.

As described above, according to this invention, dehydrated laitance can be efficiently and completely dried and turned into powder, making it possible to use it as a soil improvement material, etc.
The effect is expected to greatly open the door to the effective use of laitance, which has traditionally been treated as waste.

[Brief explanation of drawings]

FIG. 1 is a front view showing an embodiment of this invention, FIG. 2 is a side view of the same, and FIG. 3 is a plan view of the same. 3... Intermediate storage tank, 4... Fluidized drying furnace, 5... Stirrer, 8... Extruder,
11... Vibration sieve, 12°17...
Packet elevator-114...Product storage hover-118...Cyclone.

Claims (1)

[Scope of utility model registration request] A supply device that continuously supplies a fixed amount of laitance dehydrated by a vacuum dehydrator through an intermediate storage tank equipped with an agitator into a fluidized drying furnace using an extruder, and a supply device that continuously supplies a fixed amount of laitance that has been dehydrated by a vacuum dehydrator to a fluidized drying furnace through an intermediate storage tank equipped with an agitator, and a supply device that continuously supplies a fixed amount of laitance through a fluidized medium with hot air. A fluidized drying oven for drying; a separation device for continuously extracting dry laitance together with a fluidized medium from the drying oven and separating the two using a vibrating sieve; This continuous laitance drying device consists of a discharge device that sends laitance into a storage tank, and a dust collector that uses a cyclone to collect floating laitance in the drying oven.