JPH10147434A - Storage tank and foreign matter removal method for waste plastic powder and granular material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an exhaust nozzle from clogging so as to maintain smooth transportation when pulverized waste plastic powder and granular material are transported from a tank. SOLUTION: In a transport tank 1 in which waste plastic powder and granular material is stored in a storing chamber 2, sucked from an exhaust port 11 by air blowing up from the underside of a fluidized bed 4, and exhausted from the exhaust nozzle, a foreign matter exhaust nozzle 20 with opening part 21 is arranged just below the exhaust port 11 and connected through a removal valve 22 to a foreign matter tank 23. Foreign matter is liable to accumulate near the exhaust port 11, and may cause the exhaust port 11 to clog. When foreign matter is accumulated, a transport valve 12 is closed and removal valve 22 is opened so as to instantaneously move foreign matter to a foreign matter tank 23 by a pressure inside the storing chamber 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transportation technique for reusing pulverized waste plastic as fuel or the like, and more particularly to a technique for transporting while controlling the amount of transportation.

[0002]

2. Description of the Related Art Waste plastic is often reused as a fuel or a reducing agent. At the time of reuse, these plastics are pulverized through several stages to remove the metal, earth and sand mixed in each stage and to adjust the particle size. Finally, these are blown into these devices in a manner that is most suitable for reuse devices such as combustion devices. For example, when blown into a blast furnace for reducing iron ore, waste plastic powder having a grain size of 6 mm or less is temporarily stored and transported to a blow pipe while controlling the amount.

FIG. 3 shows a conventional storage tank for waste plastic powder. The transport tank 1 comprises a storage chamber 2 and a pressure chamber 3, which are separated by a fluidized bed 4.
The fluidized bed is a perforated plate bed and blows up air from the pressure chamber 3, and the inside of the pressure chamber 3 is maintained at a predetermined pressure by air blown through an air regulating valve 5. The waste plastic powder is charged from the charging port 6, and after charging, the charging valve 7 is closed.

[0004] The waste plastic powder which has descended to the fluidized bed 4 is sucked in and discharged from the discharge port 11 of the discharge nozzle 10 by the flow of air blown up from below, and the discharge amount is controlled by the on-off valve 12. . Unloading nozzle 10
Although only one system is shown in the figure, a plurality of systems are often installed, and generally, a plurality of systems are provided concentrically. In some cases, a stirrer equipped with a stirring blade is provided to stir up the particles accumulated on the fluidized bed 4 so that the particles can be easily sucked into the carry-out port 11.

[0005]

However, even in the above-mentioned waste plastic powder storage tank, heavy residues such as metals and earth and sand which could not be completely removed in the preceding steps, and also passed through a 6 mm sieve. Foreign matter, such as elongated waste plastic particles, remains slightly. These foreign objects
Despite being agitated, it accumulates in the vicinity of the carry-out port 11 and acts as a resistance for normal carry-out of the waste plastic powder.

[0006] When the resistance is generated, the amount of foreign matter is more likely to increase,
Eventually, the outlet 11 is clogged. If a blockage occurs in one system, the unloading must be stopped, and even if stopped, as long as the waste plastic powder remains in the transport tank, the air flow is reversed and removed by recalling or backwashing. I could not do it. For this reason, there is a problem that a person must enter the manhole of the transport tank to remove foreign matter.

[0007] The present invention has been made to solve the above-mentioned problem, and an object of the present invention is to provide a technique capable of automatically removing foreign substances even during operation of a transport tank.

[0008]

Means for achieving the object are the following inventions. A first invention is a storage tank for waste plastic powder, comprising the following members. (A) a transport tank provided with an inlet port for opening and closing a waste plastic powder, which is opened and closed by an inlet valve, in which an upper storage chamber and a lower pressure chamber are separated by a fluidized bed; (B) a carry-out port is provided above the fluidized bed;
A plurality of discharge nozzles having a transport valve for discharging the waste plastic powder, and (c) a foreign matter discharge nozzle having an opening immediately below the discharge port for removing foreign matter;
(D) a foreign matter tank connected to the foreign matter discharge nozzle via a removal valve and having a discharge valve at a lower portion.

The waste plastic powder storage tank temporarily stores the waste plastic powder that has been input into a transport tank,
In order to carry it out to the use destination at a predetermined supply speed, it is carried out by pressurized air from a carry-out nozzle. The loading of waste plastic powder into the transport tank is performed from the inlet provided at the top,
When the charging is completed, the charging port is closed by the charging valve. The upper part of the transport tank is a storage room, and the waste plastic powder that has been input is stored here.

[0010] The floor of the storage chamber is a multi-porous fluidized bed, which serves as a partition from the lower pressure chamber, and blows up air from the pressure chamber from below. The blown-up waste plastic powder is
It is sucked into the discharge port installed above the fluidized bed and discharged from the discharge nozzle. The carry-out nozzle is provided with a transport valve for controlling the transport amount, and the end thereof is connected to a transport pipe.

Foreign matter accumulates in the vicinity of the carry-out port, and a foreign matter discharge nozzle is provided with its opening positioned immediately below the carry-out port to remove the foreign matter. The foreign matter discharge nozzle is connected via a removing valve to a foreign matter tank that temporarily stores foreign matter. The removal valve is open only when transferring foreign matter to the foreign matter tank, and is normally closed. A discharge valve is provided at a lower portion of the foreign matter tank. When the discharge valve is opened with the removal valve closed, foreign matter in the foreign matter tank is taken out.

According to a second aspect of the present invention, there is provided the waste plastic powder storage tank described above, wherein a horizontal cross section of an opening of the foreign matter discharge nozzle is larger than a horizontal cross section of the carry-out port. If the horizontal cross section of the opening of the discharge nozzle is made larger than the horizontal cross section of the carry-out port, the above-described transfer of foreign substances is performed more efficiently. By increasing the cross section of the opening, foreign matter can be transferred from a wide range near the outlet.

According to a third aspect of the present invention, there is provided a charging port for charging the waste plastic powder above, wherein the upper storage chamber and the lower pressure chamber are separated from each other by a fluidized bed. A plurality of carry-out nozzles for carrying out waste plastic powder having a carry-out port provided therein, a foreign matter discharge nozzle opened immediately below the carry-out port, and a foreign matter tank connected to the nozzle via a removal valve. Using a storage tank of waste plastic powder, for each system of the carry-out nozzle, when foreign matter has accumulated near the carry-out port or at predetermined time intervals, the carry-out nozzle is closed and the foreign matter discharge nozzle is opened. This is a method for removing foreign matter from waste plastic powder.

As described in the first aspect of the present invention, the transfer nozzle is closed by using the foreign-matter discharge nozzle opened just below the discharge outlet of the discharge nozzle and the storage tank of the waste plastic powder attached with the member connected thereto. When the foreign matter discharge nozzle is opened, foreign matter near the carry-out port can be discharged to the outside of the transport tank.

When this discharge operation is performed for one system of discharge nozzles, the other discharge nozzles can continue discharge as usual. In addition, the time during which the discharge nozzle is closed for discharging is 5 seconds. Discharge of foreign matter may be performed only when foreign matter has accumulated near the carry-out port, or may be performed at predetermined time intervals. According to this method, it is not necessary to stop the transport operation of the storage tank, and it is possible to stably transport and supply a waste plastic powder having a sufficiently adjusted particle size without mixture.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described with reference to the drawings. In FIG. 1, the waste plastic powder is charged into the transport tank 1 from a charging port 6. The input amount is measured by a weighing scale (not shown), and when a predetermined amount is input, the input valve 7 is manually or automatically closed. The transport tank 1 includes a storage chamber 2 and a pressure chamber 3 partitioned by a fluidized bed 4, and has a carry-out nozzle 10 that opens a carry-out port 11 located above the fluidized bed 4 and has an open / close valve 12 at the other end. ing.

The main feature of the present invention is the foreign matter discharge nozzle 2
By providing 0, one end of the foreign matter discharge nozzle 20 is located just below the carry-out port 11 at the opening 21, and the other end is connected to the foreign matter tank 23 via the removal valve 22. It is more preferable to provide a foreign substance receiver 25 below the discharge valve 24 and attach a filter window 26 to the foreign substance receiver 25 because the foreign substances 30 can be collected without being scattered.

During normal transportation, the state of each valve is as follows: the air regulating valve 5 is open, the input valve 7 is closed, the on-off valve 12 is open, and the removal valve 2
2 is closed and the discharge valve 24 is closed. When the foreign matter has accumulated near the carry-out port 11, when the on-off valve 12 is closed and the removal valve 22 is opened, the foreign matter discharge nozzle 20 has the opening 21 located immediately below the carry-out port 11. Due to the pressure in the storage chamber 2, it is instantaneously transferred into the foreign substance tank 23.

At this time, since the discharge valve 24 is closed,
When the foreign matter moves, the pressure in the foreign matter tank 23 is balanced with the pressure in the storage chamber 2 and the movement stops. If the opening surfaces of the carry-out port 11 and the opening 21 are horizontal, the pressure effect is not reduced. After the transfer, the removal valve 22 is closed, the on-off valve 12 is opened, and transport is resumed. Thereafter, when the discharge valve 24 is opened, the foreign matter is discharged outside.

At this time, since the pressure in the foreign substance tank 23 is increased to the same level as the pressure in the storage chamber 2, the foreign substances may be vigorously discharged and scattered. In order to avoid this scattering, a foreign matter receiver 25 provided with a filter window 26 may be provided below the discharge valve 24. After the discharge, the inside of the foreign matter tank returns to the same pressure as the outside air.

At least two carry-out nozzles 10 are necessary so that transportation can be continued even if the on-off valve 12 of one carry-out nozzle 10 is closed, and four to six are suitable. The carry-out port 11 has a horizontal surface, and an appropriate distance from the fluidized bed is, for example, about 25 mm to 50 mm. Fluid bed 4
It is not necessary to have a stirrer to soar up the powders and particles accumulated in the tank, but if there are relatively many heavy foreign substances such as metals, it may be difficult to move them by wind power alone,
For example, it is desirable to have a stirring device provided with a blade rotating on the upper surface of the fluidized bed 4.

The removal of foreign matter may be performed when foreign matter has accumulated near the carry-out port 11.
It can be detected by a change in the pressure of the pressure chamber 3 or a change in the flow rate of the discharge nozzle 10. A pressure gauge 8 is attached to the pressure chamber 3,
The pressure is sent to an arithmetic unit (not shown), and when an increase in pressure is detected, a signal is sent to a control device (not shown) to open and close the on-off valve 1.
2 and the removal valve 22 may be opened.

Although it is necessary to perform the removing operation sequentially for a plurality of discharge nozzles, the flow meter 1 attached to the discharge nozzle
When the decrease in the flow rate is detected in step 3, the foreign matter removal operation may be performed only on the detected discharge nozzle. Alternatively, a predetermined time may be determined based on the time until the resistance due to the foreign matter increases based on experience, and the removing operation of the foreign matter may be performed every time.

[0024]

EXAMPLES A storage tank for waste plastic particles was manufactured, and the waste plastic particles were transported at a rate of 3 t / h to a blowing pipe to a tuyere tuyere. The outline of the storage tank is as shown in FIG. 1, but there are four discharge nozzles. An on-off valve 1 so that the waste plastic powder can be transported uniformly from each discharge nozzle.
2 was adjusted and the operation was performed. The pressure in the pressure chamber 3 is 6 kg / cm ²
The pressure of the blast furnace tuyere injection pipe is 4 kg / cm ² . This means that the product was transported with a pressure difference of 2 kg / cm ² .

FIG. 2 shows the vicinity of the carry-out port in the transport tank.
2A is a longitudinal sectional view, and FIG. 2B is a transverse sectional view in the fluidized bed 4. Since there are four carry-out nozzles 10,
There are also four foreign matter discharge nozzles. The foreign matter discharge nozzle 20 slightly widens at the opening 21 and is larger than the opening surface of the carry-out port 11. The diameter of the carry-out port 11 was 32 mm, while the diameter of the opening of the foreign matter discharge nozzle was 50 mm.

In order to detect accumulation of foreign matter near the carry-out port, the flow rate of the carry-out nozzle 10 was measured, and when the flow rate decreased to 70%, a valve operation for removing foreign matter was performed.
Also, no stirrer was used.

In this way, about 80 t of the waste plastic powder was transported. During this time, the number of valve operations for removing foreign substances was 5 times. 3 with the most discharge nozzles
One time was less than one time. However, everything from detection to collection of foreign matter is automatically performed, requiring no human intervention. Further, no valve operation for removing foreign matter was performed on two or more carry-out nozzles at the same time, and there was no trouble in transportation.

Further, since heavy residues such as metals and earth and sand were sufficiently removed and the waste plastic powder having a uniform particle size was stably transported, satisfactory blowing results were obtained. In the event that the carry-out nozzle or transport pipe is clogged, the pressure in the pressure chamber is released and the removal valve or the removal valve and the discharge valve are opened, even if waste plastic powder exists in the transport tank. Can be washed. In addition, the storage tank for the waste plastic powder can be used not only for transportation to the blow tube of the blast furnace tuyere, but also for transportation to another use destination.

As described above, according to the present invention, a foreign matter discharge nozzle and a foreign matter tank are provided immediately below the carry-out port from the transport tank in the waste plastic powder storage tank. Thus, when the carry-out nozzle is closed and the foreign matter discharge nozzle is opened, the foreign matter that often accumulates near the carry-out port due to the pressure of the storage chamber is transferred to the foreign matter tank. This foreign matter discharging operation can be performed manually or automatically. Further, when the foreign matter discharging operation is being performed for one discharge nozzle, the other discharge nozzles can continue the normal operation. As a result, clogging of the carry-out nozzle and transport pipe due to foreign matter is automatically removed, and no manual work is required for the removal, and waste plastic powder with uniform particle size that does not contain foreign matter is stably transported to the place of use. can do. As described above, the effect of the present invention that enables the efficient transport of clean waste plastic powder particles is great.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an outline of a waste plastic powder storage tank of the present invention.

FIGS. 2A and 2B are views showing the vicinity of a carry-out port in a transport tank according to the present invention, wherein FIG. 2A is a sectional view and FIG. 2B is a transverse sectional view.

FIG. 3 is a vertical sectional view of a conventional waste plastic powder storage tank.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Transport tank 2 Storage room 3 Pressure chamber 4 Fluid bed 6 Inlet 7 Inlet valve 10 Unloading nozzle 11 Unloading port 12 On-off valve 13 Flowmeter 20 Foreign material discharge nozzle 21 Opening 22 Removal valve 23 Foreign material tank 24 Discharge valve 25 Foreign material receiving

Continued on the front page (72) Inventor Hiroshi Igarashi 4-164-5 Tatsumidaihigashi, Ichihara-shi, Chiba (72) Inventor Haruo Watanabe 1-10-4 Sakuradai, Ichihara-shi, Chiba (72) Inventor Tokio Ohriki, Ichihara-ichimatsu, Chiba Kashima 150-5

Claims (3)

[Claims] 1. A storage tank for waste plastic powder, comprising the following members. (A) a transport tank provided with an inlet port for opening and closing a waste plastic powder, which is opened and closed by an inlet valve, in which an upper storage chamber and a lower pressure chamber are separated by a fluidized bed; b) a plurality of unloading nozzles having an on-off valve for unloading waste plastic powder having an unloading port provided above the fluidized bed, and (c) an opening just below the unloading port for removing foreign matter. A foreign matter discharge nozzle having a portion, (d)
A foreign matter tank connected to the foreign matter discharge nozzle via a removal valve and having a discharge valve at a lower portion. 2. The storage tank for waste plastic powder according to claim 1, wherein the horizontal cross section of the opening of the foreign matter discharge nozzle is larger than the horizontal cross section of the carry-out port. 3. An upper portion is provided with an inlet for charging waste plastic powder, and a discharge port is provided above the fluidized bed of a tank in which an upper storage chamber and a lower pressure chamber are separated by a fluidized bed. A waste plastic powder having a plurality of discharge nozzles for discharging the disposed waste plastic powder, a foreign matter discharge nozzle opened immediately below the discharge port, and a foreign matter tank connected to the foreign matter discharge nozzle via a removal valve. Using a body storage tank, for each system of the carry-out nozzle, when foreign matter has accumulated near the carry-out port, or at predetermined time intervals, closing the carry-out nozzle and opening the foreign matter discharge nozzle; A method for removing foreign substances from plastic particles.