JP2002046863A - Powder supply device and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To quantitatively supply powder large in a consolidating property or in a flashing property such as char from a hopper. SOLUTION: The char cut out by a table feeder 3 from the char hopper 1 is pneumatically transported by a pneumatic transport piping 6. A difference of each of detected values is converted to an electric signal by a differential pressure transducer 9 by detecting pressure by a high pressure side pressure detection seat 7 and a low pressure side pressure detection seat 8 installed on a vertical piping part 6A. It is possible to control cutting-out quantity of the char from the char hopper 1 to be constant by controlling the number of rotations of a motor 11 to rotate the table feeder 3 in accordance with the electric signal from the differential pressure transducer 9 by a supply quantity control part 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a powder supply apparatus and a method suitable for use in a case where powder stored in a hopper or the like is quantitatively cut out and transported by air.

[0002]

2. Description of the Related Art Conventionally, as a method of quantitatively cutting out powder stored in a hopper or the like and pneumatically transporting the same, for example, a cutting device of a model having a quantitative property such as a table feeder, a rotary valve, a screw feeder, or the like has been used. I have. Each of these quantitative cutout devices is a fixed-volume cutout device, and the degree of compaction or flushing property of the powder in the vicinity of the cutout device differs depending on the storage amount, and it cannot be said that stable quantitativeness can always be obtained. In particular, when the powder is a char whose main component is carbon generated when pyrolyzing waste materials, the char has a large compaction or flashing property and is a powder that is very difficult to handle.
Stable control is very difficult.

As a method for solving the above-mentioned drawback, there has been a method in which the weight of a storage tank is continuously measured, and a cut-out amount is calculated from a weight reduction to control a cut-out device. Also,
There is a method of controlling the cutting device by measuring the weight of the cut powder with an impact flow meter, a belt scale, or the like.

[0004]

However, the former method described above is adopted in an apparatus in which powder supply and cutout to the storage tank are simultaneously performed, and when powder cutout from the storage tank is plural. There was a problem that it was not possible. In addition, the latter method has a problem that the equipment is increased and it is not economical.

The present invention has been made in view of the above circumstances, and is an economical powder capable of quantitatively cutting out powder such as char having compaction or flashing properties stored in a hopper or the like and transporting it pneumatically. It is an object to provide a supply device and method.

[0006]

In order to achieve the above object, a powder supply device according to the present invention comprises a cutting device for cutting powder from a storage tank, and an air for pneumatically transporting the cut powder. A transport pipe, detecting means for detecting two pressures in the pneumatic transport pipe, differential pressure detecting means for detecting a differential pressure of each pressure detected by the detecting means, and a differential pressure detected by the differential pressure detecting means. Control means for controlling the cutting device in accordance with the differential pressure to control the amount of powder cut out.

Further, in the powder supply method according to the present invention, a pressure difference between two points of an air transport pipe for pneumatically transporting the powder cut from the storage tank is detected, and the pressure difference of the powder is detected in accordance with the differential pressure. The cutout amount is controlled.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. The present inventors, when pneumatically transporting the powder, based on the knowledge that the pressure loss generated in the transport pipe is correlated with the air flow rate and the transport rate of the powder, by making the air flow rate constant, The knowledge of the correlation between the pressure loss and the amount of powder transported was obtained. In the present embodiment, based on such knowledge, the pressure loss of the pneumatic transportation pipe is measured, and the cutting device is controlled to quantify the powder having compaction or flushing properties stored in a hopper or the like. It has become possible to carry out pneumatic transportation by cutting out.

FIG. 1 is a block diagram showing a powder supply apparatus according to an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a char hopper for storing char generated when pyrolysis of waste is performed. Char is a powder which has both consolidation and flashing properties and is very difficult to handle. Furthermore, the physical properties such as the apparent density of the char vary depending on the type of waste and the thermal decomposition temperature, and it is very difficult to perform quantitative extraction with a normal quantitative extraction device.

Reference numeral 2 denotes a vibration discharger, 3 denotes a table feeder as a cutting device, and 11 denotes a motor (VVVF) for rotating the table feeder 3. Reference numeral 4 denotes a pneumatic transport blower, which uses a constant volume blower in the present embodiment. Reference numeral 5 denotes a rotary valve, and reference numeral 6 denotes a pneumatic transportation pipe. A high pressure side pressure detecting seat 7 and a low pressure side pressure detecting seat 8 are preferably attached to the vertical pipe portion 6A in the pneumatic transportation pipe 6.

Reference numeral 9 denotes a differential pressure converter, which converts the difference between the pressure detected by the high pressure side pressure detection seat 7 and the pressure detected by the low pressure side pressure detection seat 8 into an electric signal. The supply amount control unit 12 controls the motor 11 of the table feeder 3 according to the electric signal from the differential pressure converter 12.
By controlling the number of rotations, the amount of cut out of the char is controlled to be constant.

Reference numeral 10 denotes a revolving combustion furnace, which burns the char and melts the inorganic components contained in the char. In order to stably burn char in the swirling combustion furnace 10, stable supply of char is essential.

In the above configuration, the char cut out from the char hopper 1 through the vibration discharger 2 and the table feeder 3 is sent to the air transport pipe 6 through the rotary valve 5 and transported by the air from the air transport blower 4. You. Then, in the upward vertical pipe section 6A, the pressure is detected by the high pressure side pressure detection seat 7 and the low pressure side pressure detection seat 8, and the differential pressure of each detected value is converted into an electric signal by the differential pressure converter. The supply amount control unit 12 controls the motor 1 of the table feeder 3 according to the electric signal from the differential pressure converter 12.
1 is controlled. Thus, the char hopper 1
Is controlled so that the cut-out amount of the char from is constant.

Next, this embodiment will be described in more detail based on examples. The properties of the char of the thermal decomposition product of the waste used in this example are described. -Apparent specific gravity: 0.4 to 0.7-Average particle size: 30 to 80 µm-Calorific value: 10,000 MJ / kg to 20,000 MJ / kg-Jetability index: 86-Compressibility: 31% It shows that the powder has a large index, is easily flushed, has a high degree of compression, is easily compacted, and easily causes a crosslinking phenomenon.

FIG. 2 shows the relationship between the number of rotations of the table feeder and the cutting amount when such a char is cut out only by the table feeder 3. In FIG. 2, there is a certain degree of correlation between the number of rotations of the table feeder and the amount of char cut-out, but it can be said that there is no quantitative property using the table feeder alone.

Next, an example of controlling the cutout amount according to this embodiment will be described. FIG. 3 shows that the set value of the cutting amount is 150 kg / h and 1
The graph shows the change over time in the char cutout amount and the rotation speed of the table feeder when the pressure is set to 00 kg / h. FIG.
, The cut-off amount is set to 150 kg / h from 0 minutes to 90 minutes, and the cut-off amount is set to 100 kg / h from 90 minutes to 150 minutes. The amount was obtained and the initial objectives could be achieved.

In the embodiment shown in FIG. 1, the high pressure side pressure detection seat 7 and the low pressure side pressure detection seat 8 are provided in the vertical pipe section 6A on the upside of the pneumatic transport pipe 6, but may be provided in the horizontal pipe section. Is also possible. However, if it is provided in the horizontal pipe section, it is easy to cause char accumulation when transport of the char is temporarily stopped, and the detection accuracy may be impaired. Therefore, it is preferably provided in the vertical pipe section 6A. Further, it may be provided in a pipe portion having a certain upward slope.

In the embodiment shown in FIG. 1, the table feeder 3 is used as a cutting device, but a rotary valve, a screw feeder, or the like may be used.

[0019]

As described above, according to the present invention, the differential pressure of two places in the pneumatic transport pipe of powder is detected, and the cutting device is controlled in accordance with the differential pressure to reduce the amount of powder cut. Since the control is performed, the cut-out amount of the powder can be stably controlled to be substantially constant. In particular, an excellent effect can be exhibited in the case of a powder which is very difficult to handle such as a char and has a compacting property or a flashing property.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a powder supply device according to an embodiment of the present invention.

FIG. 2 is a characteristic diagram showing a relationship between the number of rotations of a table feeder and a cutout amount when a char is cut out only by a table feeder.

[FIG. 3] The set values of the cutout amount are 150 kg / h and 10
FIG. 9 is a characteristic diagram showing a change over time in the amount of char cut-out and the number of rotations of the table feeder at 0 kg / h.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Char hopper 2 Vibration discharger 3 Table feeder 4 Pneumatic transportation blower 5 Rotary valve 6 Pneumatic transportation piping 6A Vertical piping part 7 High pressure side pressure detection seat 8 Low pressure side pressure detection seat 9 Differential pressure converter 10 Rotating combustion furnace 11 Motor 12 Supply Quantity control unit

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Nobuhiro Yazawa 2-17-15 Tsukuda, Chuo-ku, Tokyo Tsukishima Machinery Co., Ltd. F-term (reference) 3F047 AA11 AB02 CC01 3F075 BA02 BB01 CA02 CA09 CB12 CB14 CB15 CB16 CC04 CC15 CC24 CD04 DA08

Claims (7)

[Claims] 1. A cutting device for cutting powder from a storage tank, an air transport pipe for pneumatically transporting the cut powder, a detecting means for detecting two pressures of the pneumatic transport pipe, and the detecting means Detecting means for detecting the differential pressure of each pressure detected in the above, and control means for controlling the cutting device in accordance with the differential pressure detected by the differential pressure detecting means to control the amount of powder cut out. That the powder supply device. 2. The powder supply apparatus according to claim 1, wherein said detection means is provided in an upwardly sloped portion of said pneumatic transportation pipe. 3. The powder supply device according to claim 1, wherein said detection means is provided in a substantially vertical ascending portion of said pneumatic transportation pipe. 4. The powder supply apparatus according to claim 1, wherein the powder is a char whose main component is carbon generated when pyrolyzing waste material. 5. The powder supply device according to claim 1, wherein the cutting device is a table feeder, and the control unit controls a rotation speed of a motor that rotates the table feeder. 6. The powder supply apparatus according to claim 1, wherein the blower for pneumatic transportation used for the pneumatic transportation pipe is a fixed displacement blower. 7. The method according to claim 1, further comprising detecting a pressure difference between two points of a pneumatic transportation pipe for pneumatically transporting the powder cut from the storage tank, and controlling a cut-out amount of the powder according to the pressure difference. Powder supply method.