JPH1053331A - Powder and grain conveying system in gaseous flow - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a powder and grain conveying system which has its failure incidence decreased and its maintenance facilitated by a means for vertically moving a valve element in place of rotational means such as a quantative feeder or a rotary valve and which continuously conveys an invariably fixed amount of powder and grain without causing pulsation. SOLUTION: A powder or grain conveying system comprises a tank 1 having a bottom plate 1a with an opening therein and storing powder and grain M, and a discharge line 4 connected to the tank 1, and a valve 5 installed the tank 1 in vertically movable manner to adjust the discharge area of the opening and having a plurality of gas injecting holes injecting gas from inside to downward, and a transferring pipe 12 connected to the discharge line 4 mixing a gas delivered from the gas source with the falling powdered or granular material passing down through the space between the discharge opening, and a gas supplying path 9, 10, to supply to the valve body to be discharged from the plurality of holes.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for guiding a powdery or granular material such as pulverized coal or fine ore contained in a tank into a transport pipe connected to a gas source such as an air source or a nitrogen gas source. The particles from the tank are transported by a transport gas (air or nitrogen gas, etc.) in a transport pipe, for example, an annealing furnace,
The present invention relates to an apparatus for transporting granular material by a gas flow used to transport gas as a fuel to an industrial furnace such as a blast furnace.

[0002]

2. Description of the Related Art Conventionally, pulverized coal such as pulverized coal and flour stored in a tank is guided to a transportation pipe arranged outside the tank and connected to a gas source such as an air source. Japanese Patent Publication No. 58-10333 (see FIG. 1 of this publication) discloses an apparatus for transporting particles by gas transported in a transport pipe. This will be described with reference to FIGS.

As shown in FIG. 8, in a conventional granular material transport apparatus using a gas flow, a cushion tank 53 is continuously provided at a lower end of a funnel-shaped portion 52 of a tank body (silo body) 51. A guide path 58 is provided from an outlet 55 of a built-in fixed-quantity feeder 54 to a transport pipe 57 via a rotary valve 56. Further, a plurality of blades 5
A back filter 59 for preventing the air flow (positive pressure) in the transport pipe 57 from flowing back to the tank body side on the inner wall surface of the casing of the rotary valve 56 having 6a.
Is opened (see FIG. 9), and air is fed into the granular material M through the funnel-shaped portion 52 of the tank body 51 so that the granular material M
The air slider 61 for assisting the flow of the air is attached. The granular material M cut out by the fixed-quantity feeder 54 and sequentially transported downward by the blades 56a of the rotary valve 56 is transported by a transport pipe 57 connected to an air source.
It is designed to be pneumatically transported by the air flow inside.

[0004]

However, in the above-mentioned conventional granular material transporting apparatus, the fixed-quantity feeder 54 and the rotary valve 56 which continuously rotate for a long time to discharge the granular material from the tank 51 to the transport pipe 57 are used. Therefore, the fixed feeder 54 and the rotary valve 56 have a disadvantage that they frequently occur failures, and that they are disposed in a narrow space, so that maintenance work takes a lot of time. Was.

Further, the powder M from the fixed-quantity feeder 54
Is held between the respective blades 56a, 56a of the rotary valve 56 and supplied into the transport pipe 57. Therefore, when the amount of the granular material transported per unit time is small,
Precise temperature control is necessary when pulsation occurs and a fixed amount of powdered material cannot be transported continuously at all times.For example, when pulverized coal is transported as gas to a burner of an industrial furnace as a fuel, fine temperature control is required. There was a problem that it could not be applied to industrial furnaces.

Accordingly, the present invention relates to a conventional powder / particle transport apparatus for guiding a powder / particle from a tank to a transport pipe disposed outside the tank and transporting the powder / granulate by a transport gas flowing through the transport pipe. By adopting a means for moving the valve body up and down with respect to the opening of the tank bottom plate in place of a rotating means such as a feeder or a rotary valve, it is possible to reduce a failure rate and facilitate maintenance, and It is an object of the present invention to provide an apparatus for transporting a granular material by a gas flow, which can continuously transport a constant amount of a granular material without pulsation.

[0007]

In order to achieve the above-mentioned object, the present invention provides an apparatus for transporting granular material by gas flow, comprising a tank bottom plate provided with an opening, and a tank for storing the granular material. A powder discharge passage connected to the tank at a lower portion, and a plurality of powder / grain discharge passages provided to be movable up and down in the tank so as to adjust the opening area of the opening, and for ejecting gas downward from the inside thereof. A valve body having a gas ejection hole, and a gas body which is connected to the particulate body discharge path and mixes powder particles flowing down a gap with the valve body at the opening into a transport gas supplied from a gas source; It is characterized by comprising a transport pipe for transporting, and a valve section ejection gas supply pipe for supplying gas ejected from the plurality of gas ejection holes to the valve body. The apparatus for transporting a granular material by the gas flow is configured to introduce a gas that pressurizes the granular material contained in the tank downward to the tank in order to finely adjust a transport amount of the granular material. A pressurized gas supply pipe can be provided.

In the apparatus for transporting granular material according to the present invention, a valve is provided in the tank in place of a conventional rotary device such as a fixed-quantity feeder or a rotary valve, and the valve is moved up and down with respect to the opening of the tank bottom plate. Since the valve is operated to adjust the opening area of the opening, the valve element only needs to be activated at the start and stop of transport and when the amount of powdered material transported is changed. The occurrence rate can be reduced and maintenance can be facilitated.

Further, in the granular material transport apparatus according to the present invention, a plurality of gas ejection holes are provided in the valve body, and a gas such as air is ejected downward from the inside of the valve body. The powder in the tank can smoothly flow down from the gap between the valve body at the opening of the tank bottom plate,
It is possible to constantly transport a fixed amount of the granular material without pulsation.

[0010] When a gas supply pipe for pressurizing the granular material contained in the tank is introduced into the tank for introducing a gas for compressing the granular material downward, the supply amount of the gas for compressing the granular material is provided. By fine adjustment of the amount, fine adjustment of the amount of transport of the granular material can be performed.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram showing an example of a granular material transport device using a gas flow according to the present invention, FIG. 2 is a diagram for explaining an opening provided in a tank bottom plate of the tank shown in FIG. 1, and FIG. FIG. 4 is a side sectional view of the valve body shown in FIG. 1, and FIG. 5 is a front view of the valve body shown in FIG.

In FIG. 1, reference numeral 1 denotes a tank for accommodating a granular material M such as pulverized coal, for example.
Is connected to a funnel-shaped portion below the cylindrical body, a tank bottom plate 1a is provided at the lower end of the funnel-shaped portion, and an upper lid 1 is provided on the cylindrical body.
c is provided. The tank bottom plate 1a is provided with a substantially T-shaped opening 1b in plan view (FIG. 2).
), A hopper 3 provided with a ball valve 2 for supplying a granular material is disposed on the tank lid 1c. Reference numeral 4 denotes a funnel-shaped powder discharge passage connected to the tank 1 below.

Inside the tank 1, the powder M is moved up and down with respect to the opening 1b of the tank bottom plate 1a and is inserted into the opening 1b in order to transport the powder M in a predetermined amount according to the set value. A valve element 5 to be described later for adjusting the opening area of the portion 1b
And a hollow rod-shaped valve stem 6 connected to the valve body 5 and extending in the vertical direction. And one end is connected to the valve rod 6 via the connection link part, and the other end is configured so that the valve body 5 can be moved up and down by the handle 7 drawn out of the tank. 7a is a handle support member with a valve opening scale, and 8 is a rubber seal member for sealing the handle through hole of the tank 1.

The valve element 5 is, as shown in FIGS.
The inside is hollow, and has a triangular shape as a whole in a side view (see FIG. 4). Then, in order to smoothly slide up and down in a state of being inserted into the opening 1b, the valve body 5 is
As its back plate, it has a guide plate 5a inserted into the wide portion of the opening 1b. The valve body 5 passes through the gas introduction passage 6a of the valve rod 6 on the lower inclined surface 5b of the valve body 5, that is, the lower inclined surface 5b that forms a gap between the opening 1b and the tank bottom plate 1a. In this example, which is supplied into the inside 5, a plurality of gas ejection holes 5c for ejecting pressurized air downward are provided. The hole diameter of each gas ejection hole 5c is about 2 to 3 mm.

In this example, a valve section gas supply pipe 9 connected to a pressure air source (not shown) is connected to the outer surface of the cylindrical body of the tank 1, while the supply pipe 9 is connected to the inside of the tank 1. A bendable flexible tube 10 that connects the valve stem 6 to the gas introduction passage 6a is provided. The valve part ejecting gas supply pipe 9, the flexible tube 10, and the valve rod 6 having the gas introduction passage 6a supply the valve body 5 with pressurized air to be ejected from the plurality of gas ejection holes 5c. Make up the road. Further, on the outer surface of the cylindrical body of the tank 1, a pressurized powder body connected to a pressurized air source (not shown) for introducing air for pressurizing the powder M in the tank 1 downward into the tank 1 is provided. The gas supply pipe 11 is connected.

The lower end of the powdery material discharge passage 4 connected to the tank 1 below is provided with a transport pipe 12 connected to a pressure air source (not shown) for pneumatically transporting the powdery material M from the tank 1 to, for example, an industrial furnace. It is connected to the middle part. The pressure and the flow rate of the air flowing through the transport pipe 12, the gas supply pipe 9 and the gas supply pipe 11 for pressurizing the granular material can be adjusted to required values for each pipe. I have.

The operation of the granular material transporting apparatus having the above configuration will be described. In carrying out pneumatic transportation of a certain amount of granular material M charged into the tank 1 from the hopper 3 via the ball valve 2 per unit time, first, each of the pipes 12, 9, 1
The supply of a predetermined amount of pressurized air to each of the first and second airbags is started.
Thereafter, in this example, the handle 7 is manually operated while observing the valve opening scale so that the valve opening becomes a predetermined valve opening according to the amount of the granular material transported. As a result, the valve element 5 is lifted upward, and the valve element lower inclined surface 5b at the opening 1b.
A gap corresponding to the amount of the granular material transported is formed between the fuel tank and the tank bottom plate 1a, and the granular material M in the tank 1 flows down from the gap together with the air flow jetted downward from the valve element 5. The powder is continuously supplied into the transport pipe 12 through the powder discharge path 4.

As described above, in the granular material transport device according to the present invention, the valve element 5 is provided in the tank 1 instead of the conventional rotary device such as a fixed-quantity feeder or a rotary valve, and is provided in the opening 1b of the tank bottom plate 1a. On the other hand, since the valve element 5 is moved up and down to adjust the opening area of the opening 1b, the valve element 5 can be actuated only at the start / stop of transport and at the time of changing the amount of granular material transported. Well, compared to conventional equipment,
The failure occurrence rate can be reduced and maintenance can be facilitated. Further, a plurality of gas ejection holes 5c are provided in the valve body 5,
Since the air flow is jetted downward from the inside of the valve body, the powder M in the tank 1 is moved toward the transport pipe 12 through the opening 1.
It is possible to smoothly flow down from the gap with the valve element 5 in b, and it is possible to continuously transport a constant amount of powder and granules without pulsation.

FIG. 6 is a graph showing an example of the relationship between the valve opening and the amount of granular material transported in the granular material transport device having the structure shown in FIG. In this graph, pulverized coal is used as the granular material M, pressurized nitrogen gas is used as the gas, and the nitrogen gas flow rate of the valve section ejection gas supply pipe 9 is set to a constant value (100 Nl /
min), and the valve opening degree (opening 1) when the nitrogen gas flow rate of the gas supply pipe 11 for pressurizing the granular material is used as a change parameter.
The relationship between the width dimension of the gap in b) and the amount of transport of the granular material was obtained from experiments. The flow rate of the nitrogen gas in the transport pipe 12 was constant at 350 Nl / min. The pressure (gauge pressure) of the nitrogen gas flowing through the supply pipe 9 at the tank 1 inlet side position is 5.0 kPa, and the pressure (gauge pressure) of the nitrogen gas flowing through the supply pipe 11 at the tank 1 inlet side position is The pressure (gauge pressure) of the nitrogen gas flowing through the transport pipe 12 at the connection position with the powdery material discharge path 4 is 4.9 kPa.

As shown in FIG. 6, there is a direct proportional relationship between the degree of valve opening and the amount of granular material transported. It can be seen that fine adjustment can be made by adjusting the flow rate of the nitrogen gas in the gas supply pipe 11. The flow rate of the nitrogen gas in the valve section discharge gas supply pipe 9 does not directly affect the adjustment control of the transport amount of the granular material. The typical operating conditions of this apparatus are as follows: granular transport rate: 6.25 kg / mi
n, solid-gas ratio: 10, nitrogen gas flow rate of transport pipe: 350N
Liter / min, the flow rate of nitrogen gas in the gas supply pipe for pressurizing the granular material: 50 N liter / min, and the flow rate of nitrogen gas in the gas supply pipe for ejecting the valve section: 100 N liter / min. The solid-gas ratio is a value indicating the concentration of the granular material in the transport airflow, and under this typical operating condition, 6250 / [(350+
50 + 100) × nitrogen gas density 1.25 g / l]
Therefore, the value of the solid-gas ratio is 10.

FIG. 7 is a configuration diagram schematically showing another example of the apparatus for transporting a granular material by a gas flow according to the present invention. The difference from the apparatus of FIG. 1 is that a single large tank is provided with a plurality of valve elements so that it can be applied to the transportation of a large amount of powder and granular material.

That is, as shown in FIG. 7, a plurality of funnel-shaped portions (in this example, 4
2), tank bottom plates 21a _A , 21a _B , 21a having openings similar to those in FIG.
_C, with 21a _D is provided, funnel-shaped granular material discharge passage 24A, 24B, 24C, 24D are connected. The upper lid 21c of the tank 21 is provided with a ball valve 22 for supplying the granular material to the tank 21, and the air for pressurizing the granular material M in the tank 21 downward is supplied to the tank 2.
A gas supply pipe 31 for pressurizing the granular material connected to a source of pressurized air (not shown) is connected to introduce the gas into the inside 1.

[0023] Then, inside the first tank funnel portion of the right end in FIG. 7, the opening of said FIGS. 3-4 in the same structure as that shown in tank bottom plate 21a _A in (not shown) On the other hand, a valve body 25A that moves up and down, and a valve rod 26A that has a gas introduction passage (not shown) therein and is connected to the valve body 25A and extends in the vertical direction are provided. Further, a valve body driving device 27A for moving the valve body 25A up and down through the valve shaft 26A is connected to the upper end of the valve stem 26A drawn out of the tank 21, and a plurality of gas ejections from the valve body 25A are performed. A valve ejection gas supply pipe 29 for supplying pressurized air ejected from the hole through the gas introduction passage.
A is connected. Then, the lower end of the powder / particle discharge path 24A connected to the first tank funnel-shaped portion below is connected to a pressure air source (not shown) for pneumatically transporting the powder M from the tank 21 to, for example, an industrial furnace. It is connected to an intermediate portion of the pipe 32A. With the same configuration, the other three valve bodies 25B, 25C, and 25D are also provided in the tank 21.

[0024] Also in such a granular material transport apparatus in which a plurality of valve elements are provided in such a tank, the occurrence of failures is extremely small, maintenance is easy, and similar to that shown in FIG. In addition, it is possible to constantly transport a fixed amount of powder and granules without pulsation.

[0025]

As described above, according to the apparatus for transporting particulates by gas flow according to the present invention, the particulates are guided from the tank to the transport pipe disposed outside the tank, and the particulates are transported to the transport pipe. In a granular material transport device that transports gas by a transport gas flowing through a valve, the valve element is moved up and down with respect to the opening of the tank bottom plate in place of the conventional rotating means such as a fixed-quantity feeder or a rotary valve. In addition, it is possible to reduce the failure occurrence rate and facilitate the maintenance, and it is possible to continuously transport a constant amount of powder and granules without pulsation.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an example of an apparatus for transporting a granular material by a gas flow according to the present invention.

FIG. 2 is a view for explaining an opening provided in a tank bottom plate of the tank shown in FIG. 1;

FIG. 3 is a plan view of the valve body shown in FIG.

FIG. 4 is a side sectional view of the valve body shown in FIG. 1;

FIG. 5 is a front view of the valve body shown in FIG. 1;

6 is a graph showing an example of a relationship between a valve opening degree and a granular material transport amount in the granular material transport device having the structure shown in FIG.

FIG. 7 is a configuration diagram schematically showing another example of the apparatus for transporting a granular material by a gas flow according to the present invention.

FIG. 8 is a configuration diagram of a conventional apparatus for transporting a granular material using a gas flow.

FIG. 9 is a diagram for explaining a main part of FIG. 8;

[Explanation of symbols]

Reference Signs List 1 tank 1a tank bottom plate 1b opening 1c
Upper lid 2 ... Ball valve 3 ... Hopper 4 ... Pulverized material discharge path 5 ... Valve 5a ... Guide plate 5b ... Lower inclined surface
5c: gas ejection hole 6: valve stem 6a: gas introduction passage 7
… Handle 7a… Handle support member with valve opening scale 8… Rubber seal member 9… Valve ejection gas supply pipe 1
0 ... flexible tube 11 ... granular material pressurizing gas supply pipe 12 ... transporting pipe 21 ... tank 21a _A, 21
a _B , 21a _C , 21a _D ... tank bottom plate 21c ... top cover 22 ... ball valve 24A, 24B, 24C, 24
D: Powder discharge path 25A, 25B, 25C, 25D ...
Valve body 26A, 26B, 26C, 26D ... Valve stem 27
A, 27B, 27C, 27D ... valve body driving device 29A,
29B, 29C, 29D ... valve part ejection gas supply pipe 31 ...
Gas supply pipe for powder pressurization 32A, 32B, 32C, 3
2D… Transport piping M… Powder

Claims (2)

[Claims] A tank bottom plate provided with an opening;
A tank for accommodating the granular material, a granular material discharge path connected to the lower part of the tank, and a vertically movable member provided in the tank to adjust an opening area of the opening, and a lower part than the inside thereof. A valve body having a plurality of gas ejection holes for ejecting gas toward the valve body, and connected to the powdery material discharge path, and a transport gas supplied from a gas source flows down a gap between the valve body at the opening at the opening. A gas flow, comprising: a transportation pipe for mixing and transporting gas by mixing powder and granules; and a valve section ejection gas supply pipe for supplying gas ejected from the plurality of gas ejection holes to the valve element. By granular material transport equipment. 2. The method according to claim 1, further comprising a gas supply pipe for pressurizing the granular material contained in the tank to introduce a gas for compressing the granular material downward into the tank. apparatus.