JP4952885B2 - Table type powder supply apparatus and control method thereof - Google Patents

Description

  The present invention relates to a table type powder supply apparatus for continuously supplying a fixed amount of powder by a rotating cutting disk and a control method therefor.

  For example, an incinerator exhaust gas treatment facility is continuously supplied with a predetermined amount of powder such as an alkaline agent or activated carbon by a table type powder supply device. The table type powder supply device is a hopper for storing powder. And a table feeder having a cutout disk rotatably arranged at the lower part of the hopper, and a drive means for driving the cutout disk to rotate. The drive means rotates the cutout disk, and is formed on the cutout disk. The powder supplied from the hopper is transferred to the supply port, discharged from the discharge port, and supplied to the flue or the like of the incinerator.

  By the way, in this type of table type powder supply apparatus, in order to change the amount of powder supply (cutout amount), the rotation speed of the cutout disk may be changed. In order to change the rotation speed of the cutout disk, an inverter, There is a method using a variable speed reducer or the like.

Patent Documents 1 and 2 disclose techniques for changing the rotational speed of a cut-out disk by a variable speed motor such as a servomotor.
Japanese Patent No. 3319837 Japanese Utility Model Publication No. 4-19483

  However, in the conventional method, a proportional relationship is established between the rotation speed of the cutting disk and the powder supply amount (cutting amount) in the low-speed rotation region, but the supply formed on the cutting disk when a certain rotation speed is exceeded. Since the peripheral speed of the port increases, the supply of powder to the supply port and the discharge of powder from the supply port to the discharge port cannot follow the peripheral speed of the supply port, and the supply and discharge efficiency of the powder decreases. However, there is a problem that a proportional relationship is not established between the rotation speed of the cutting disk and the amount of powder supply (cutting amount).

  Here, FIG. 7 shows an example of the relationship between the rotation speed of the cutting disk and the powder supply amount (cutting amount). In FIG. 7, the horizontal axis is the frequency (Hz) proportional to the rotation speed, and the vertical axis is the powder. The amount of cut out (kg / h). In FIG. 7, the straight line A is the theoretical value of the cutting amount for each rotational speed (frequency), the curve B is the actual value of the cutting amount, and the actual cutting amount of the powder increases the rotational speed (frequency). It can be seen that the value drops greatly from the theoretical value.

  As a solution to the above problem, a method of increasing the opening area and number of the supply ports and slowing the rotation speed of the cutting disk can be considered. According to this method, the powder supply (cutting) interval is reduced in the low-speed rotation region. It becomes large and it becomes intermittent supply similar to a pulsation phenomenon, and continuous supply cannot be realized. In this method, the powder supply amount (cutout amount) is unstable and non-uniform, and the supply accuracy (cutout accuracy) is low, which is high in an incinerator exhaust gas treatment facility where continuous injection operation is desired. The effect cannot be expected.

  The present invention has been made in view of the above problems, and its objective is to ensure high powder supply efficiency and discharge efficiency over a wide range of rotation speeds, and to secure a theoretical cutout amount in a high rotation range. It is an object of the present invention to provide a table type powder supply apparatus and a control method thereof.

In order to achieve the above object, the invention described in claim 1 is a hopper for storing powder, a table feeder having a cutting disk rotatably disposed in a lower casing below the hopper, and an upper side of the cutting disk. And a driving means for rotationally driving the cut-out disk,
By rotation of the cutting disc, a powder from the hopper is filled into a plurality of supply ports formed on the outer peripheral edge of the cutting disc at an equiangular pitch and facing an opening formed in the top plate, After the powder filled in the supply port is scraped off by the top plate, the powder is transferred on the lower casing, and the supply port filled with the powder opens to the discharge port formed in the lower casing In the table-type powder supply apparatus configured such that the powder falls to the discharge port by its own weight and is discharged ,
With constituting said driving means at variable speed motor, the rotational speed of the cut disk, when the supply port is located in the scope of supply and / or discharge range of the powder than when located at the other ranges Is also set to be small .

  According to a second aspect of the present invention, in the first aspect of the invention, the variable speed motor is a servo motor.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, an origin detection sensor for detecting the position of the supply port is provided.

The invention according to claim 4 is a hopper for storing powder, a table feeder having a cutting disk rotatably disposed in a lower casing below the hopper, a top plate covering the top of the cutting disk, Provided with drive means for rotationally driving the cutting disc
By rotation of the cutting disc, a powder from the hopper is filled into a plurality of supply ports formed on the outer peripheral edge of the cutting disc at an equiangular pitch and facing an opening formed in the top plate, After the powder filled in the supply port is scraped off by the top plate, the powder is transferred on the lower casing, and the supply port filled with the powder opens to the discharge port formed in the lower casing As a control method of the table-type powder supply device configured such that the powder falls to the discharge port by its own weight and is discharged ,
The rotational speed of the cutting disc when the supply port is located in the powder supply range and / or the discharge range is smaller than that when the supply port is located in a range other than the powder supply range and the discharge range. It is characterized by setting.

  The invention described in claim 5 is the invention described in claim 4, characterized in that the position of the supply port is detected by an origin detection sensor.

  According to the present invention, since the rotation speed of the cutting disk is set low in the supply range for supplying the powder to the supply port and the discharge range for discharging the powder to the discharge port, the supply of the powder to the supply port and the supply port The discharge of the powder from the outlet to the outlet can follow the peripheral speed of the supply port, the powder supply and discharge efficiency is kept high over a wide rotation speed region, and the rotation speed and the powder supply amount (cut out) A proportional relationship is established, and the theoretical cutout amount in the high rotation region can be secured.

Further, according to the present invention, in the range other than the supply range and the discharge range, the peripheral speed of the cut disk is set high , so that the one rotation period of the cut disk can be made the same as the conventional value. since it is possible to realize a continuous supply with as short as possible the body supply (cut) interval, a powder supply amount (cut amount) is possible to ensure a becomes stable and uniform, high feed accuracy (cut precision) Can do.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 is a basic configuration diagram of a table type powder supply device according to the present invention, FIG. 2 is a configuration diagram of a control system of the table type powder supply device, and FIG. 3 is a plan view schematically showing a configuration of a table feeder. is there.

  In FIG. 1, reference numeral 1 denotes a hopper in which powders such as an alkali agent and powdered activated carbon are stored. A table feeder 2 is provided at a lower portion of a straight body portion 1 a extending perpendicularly to a lower portion of the hopper 1. ing. The table feeder 2 is driven by a servo motor 3 as driving means, and a control panel 4 is connected to the servo motor 3. As a driving means, a variable speed motor other than the servo motor 3 can be used.

  Here, the structure of the said table feeder 2 is demonstrated based on FIG.

  As shown in FIG. 3, a disc-shaped cut-out disk 6 is supported on the upper end flange portion 5 a of the lower casing 5 so as to be horizontally rotatable. The cut-out disk 6 has a rotating shaft 6a that integrally extends vertically downward from the central portion thereof, and the rotating shaft 6a passes through a circular hole (not shown) formed in the central portion of the lower casing 5 so as to be rotatable. is doing. Then, the rotational power from the servo motor 3 is transmitted to the rotary shaft 6a through a power transmission mechanism (not shown), so that the cutting disk 6 is rotationally driven at a predetermined speed.

  Further, nine semicircular supply ports (mass) 6b forming a powder storage space are formed on the outer peripheral edge of the cutting disk 6 at an equal angular pitch (40 ° pitch). A circular discharge port 5b is opened at one location of the upper end flange portion 5a. When the cutting disk 6 rotates, the supply port 6b formed on the outer peripheral edge thereof is selectively opened sequentially to the discharge port 5b, and the powder stored in the hopper 1 is transferred as described later. It falls to the discharge port 5b by its own weight and is discharged. Although not shown in the drawing, the top of the cutting disk 6 is covered with a top plate, and a semicircular opening is opened on the top plate, and the powder in the hopper 1 is supplied to the cutting disk 6 from this opening. The mouth 6b is filled. As the cutting disk 6 rotates, the powder supplied onto the supply port 6b is scraped off by the top plate.

  Next, the configuration of the control system of the table type powder supply apparatus will be described with reference to FIG.

  The control panel 4 is provided with a CPU 7 and a servo amplifier (converter) 8 which are control means. The servo amplifier 8 converts a control signal from the CPU 7 into a current value and the like and supplies it to the servo motor 3. The servo motor 3 is driven and controlled. When a servo motor with an amplifier is used as the driving means, the servo amplifier 8 does not need to be provided on the control panel 4.

  By the way, the CPU 7 has an origin detection sensor 10 for detecting a signal from the powder level meter 9 attached to the straight body portion 1a of the hopper 1 and the position of the supply port 6b of the cutting disk 6 as shown in FIG. And an injection amount setting signal 11 are input.

  Here, the powder level meter 9 measures the amount of powder in the hopper 1 and transmits the signal to the CPU 7. The CPU 7 determines that the level of the powder surface in the hopper 1 is H (high level). ) When it is above, the drive of the table feeder 2 is turned on, and when the powder surface level is L (low level) or less, the drive of the table feeder 2 is turned off. A weight meter such as a load cell may be used in place of the powder level meter 9.

  The injection amount setting signal 11 is a signal for setting the amount of powder to be cut out (supply amount) from the table feeder 2.

  By the way, as shown in FIG. 1, the discharge line 12 extending downward from the table feeder 2 is connected to a supply line 14 extending from the discharge side of the blower 13 via an ejector 15. Here, the discharge line 12 is connected to a discharge port 5b formed in the lower casing 5 shown in FIG.

  As shown in FIG. 1, the supply line 14 extending from the discharge side of the blower 13 extends to a flue 16 of an incinerator (not shown), and an end thereof is smoked via a flue blow valve 17 and a blow nozzle 18. It opens to the inside of the road 16.

  Next, the operation of the table-type powder supply apparatus configured as described above will be described.

  When the table type powder supply apparatus is operated and the level of the powder surface in the hopper 1 detected by the powder level meter 9 shown in FIG. 2 is H or higher, the CPU 7 is set by the injection amount setting signal 11. A control signal corresponding to the amount of powder cut out is output to the servo amplifier 8. Then, the servo amplifier 8 drives and controls the servo motor 3 in accordance with a control signal from the CPU 7. The servo motor 3 incorporates a position sensor 3a called a rotary encoder.

  Thus, when the servo motor 3 is driven as described above, the rotational power is transmitted to the table feeder 2 through a power transmission mechanism (not shown), and the cutting disc 6 of the table feeder 2 rotates at a predetermined speed. Driven. Then, the powder stored in the hopper 1 is formed on a top plate (not shown) among the nine supply ports 6b (see FIG. 3) formed on the outer peripheral edge of the cutting disk 6 of the table feeder 2. The powder charged in the opening and filled in the supply port 6b is transferred on the lower casing 5 along the outer peripheral edge of the cutting disk 6 as the cutting disk 6 rotates. When the supply port 6b filled with powder reaches the discharge port 5b of the lower casing 5 shown in FIG. 3 and opens to the discharge port 5b, the powder filled in the supply port 6b is discharged by its own weight. And is discharged out of the table feeder 2. Thereafter, in the same manner, along with the rotation of the cutting disk 6, the supply port 6b of the cutting disk 6 sequentially opens to the discharge port 5b of the lower casing 5, and the powder is sequentially discharged to the discharge port 5b by a predetermined amount.

  On the other hand, the blower 13 shown in FIG. 1 is driven, and the air discharged from the blower 13 flows through the supply line 14 toward the flue 16, but this air passes through the ejector 15 so The pressure is generated, and the powder cut out by a predetermined amount from the table feeder 2 is sucked from the discharge line 12 connected to the discharge port 5b to the ejector 15, and the backflow to the table feeder 2 side is prevented. As a method of preventing the back flow of the powder cut out from the table feeder 2, as shown in FIG. 4, the discharge line 12 is connected to the supply line so that the powder flows along the air flow direction in the supply line 14. Alternatively, a configuration may be adopted in which the connection is made obliquely with respect to 14.

  Thus, the powder, which is cut out from the table feeder 2 by a predetermined amount and sucked from the discharge line 12 to the ejector 15, flows along the supply line 14 toward the flue along with air at a predetermined flow rate in the direction indicated by the arrow (this embodiment). In the embodiment, the air flows at 20 to 30 m / s) and is blown into the flue 16 from the blow nozzle 18. In this way, the powder stored in the hopper 1 is cut out by a predetermined amount by the table feeder 2 and continuously supplied to the flue 16 of the incinerator. It is controlled by adjusting the rotational speed of the disk 6. Specifically, the amount of powder supplied increases as the rotational speed of the cutting disk 6 increases.

  Here, FIG. 7 shows an example of the relationship between the rotation speed (frequency) of the cut-out disk and the powder supply amount (cut-out amount). In FIG. 7, the straight line A represents the cut-out amount for each rotation speed (frequency) of the cut-out disk. It can be seen that the powder supply amount (cutout amount) increases linearly in proportion to the increase in the rotation speed (frequency) of the cutout disk.

  By the way, as described above, when the rotational speed of the cutting disk 6 exceeds a certain value, the peripheral speed of the supply port 6b formed in the cutting disk 6 increases, so that the supply of powder to the supply port 6b is performed. The discharge of the powder from the supply port 6b to the discharge port 5b cannot follow the peripheral speed of the supply port 6b, and the supply and discharge efficiency of the powder is lowered. In practice, as shown by the curve B in FIG. There is a problem that a proportional relationship is not established between the rotation speed and the powder supply amount (cutout amount).

  Therefore, in the present invention, the following control method is adopted.

  That is, in the present invention, the rotational speed (peripheral speed) of the cutting disk 6 when the supply port 6b of the cutting disk 6 is located in the powder supply range and / or the discharge range, and the supply port 6b is the powder supply range. And / or it was set to be smaller than that when located in a range other than the discharge range. This can be achieved by using the servo motor 3 which is a variable speed motor as the driving means of the cutting disk 6. However, the time (cycle) for one rotation of the cut-out disk 6 is unchanged and is the same as the conventional value.

  Here, the said control method is demonstrated based on FIG.5 and FIG.6.

  FIG. 5 is a schematic plan view of the cut disk showing the rotation range of the supply port, and FIG. 6 is a timing chart showing control of the rotation speed (circumferential speed) of the cut disk in each rotation range of the supply port. Note that the following description will be given focusing on one supply port 6b for convenience.

As shown in FIG. 5, one rotation of the supply port 6b of the cutting disc 6 is performed in an angle range θ ₁ (referred to as “supply range a”) in which the supply port 6b receives the supply of powder. An angle range θ ₂ (referred to as “moving range b”) in which the supply port 6b that receives the body transfers the powder to the discharge port 5b and an angle range θ ₃ (in which the powder is discharged to the discharge port 5b) It is divided into an “exhaust range c”) and an angular range θ ₄ (referred to as “moving range d”) in which the supply port 6b that has become empty after discharging the powder moves to the supply range a. Here, θ ₁ + θ ₂ = θ ₃ + θ ₄ = 180 °.

And Thus, in the present invention, when the supply port 6b is located at the discharge range c and the supply range a, as shown in FIG. 6, the low speed U _L of the peripheral speed of the cut-out disc 6 (e.g., 0.1 5 cm / s), when the operation is performed for a short time t ₁ and t ₃ , respectively, and the supply port 6b is positioned in the other movement ranges b and d, the peripheral speed of the cut-out disk 6 is set to a high speed U _H ( For example, it is set to 10 cm / s or more) and is operated for times t ₂ and t ₄ (> t ₁ and t ₃ ), respectively. The time (period) T (= t ₁ + t ₂ + t ₃ + t ₄ ) for the cut disk 6 to make one rotation is the same as the period of a conventional cut disk that rotates at a constant speed. The supply range a, the movement range b, the discharge range c, and the movement range d are accurately set by detecting the position of the supply port 6b and the like by the origin detection sensor 10 shown in FIG. In general, the servo motor 3 incorporates a position sensor 3a called a rotary encoder, and the zero point information is inputted from the origin detection sensor 10 so that the angle (position) of the cut-out disk 6 can be easily determined. Features are provided.

As described above, in the present invention, the supply range a for supplying the powder to the supply port 6b and the discharge range for discharging the powder to the discharge port 5b without changing the time (period) T in which the cutting disk 6 makes one rotation. in c, since the peripheral speed of the cut disk 6 is set to the low speed U _L, the discharge of the powder to the discharge port 5b follows the circumferential speed of the feed opening 6b from the supply and the supply port 6b of the powder into the supply port 6b As a result, the powder supply and discharge efficiency is kept high, and a proportional relationship is established between the rotational speed and the powder supply amount (cutout amount).

  Here, FIG. 7 shows an example of the relationship between the rotation speed (frequency) of the cutting disk and the powder supply amount (cutting amount). In the same figure, the straight line C represents each of the table type powder supply devices according to the present invention. The amount of cutting actually measured with respect to the rotation speed (frequency) is shown. The result shown by the straight line C shows that according to the present invention, a proportional relationship is established between the rotational speed and the powder supply amount (cutout amount), and the powder cutout is close to the theoretical value for each rotational speed (frequency). The amount is obtained.

In the present invention, in the moving ranges b and d other than the supply range a and the discharge range c, the peripheral speed of the cut disk 6 is set to the high speed U _H , so that the period T of one rotation of the cut disk 6 is the same as the conventional value. It is the same, there is no change in the powder supply (cutting) interval, continuous supply can be realized, and the powder supply amount (cutting amount) is stable and uniform. Accuracy). For this reason, a high chemical effect can be expected in an incinerator exhaust gas treatment facility where continuous injection operation is desired.

  Although the above description has been made focusing on one supply port 6b, in the present embodiment, since nine supply ports 6b are formed in the cut-out disk 6, the speed control is performed every angle of 40 °.

It is a basic lineblock diagram of a table type powder supply device concerning the present invention. It is a block diagram of the control system of the table type powder supply apparatus which concerns on this invention. It is a top view which shows typically the structure of the table feeder of the table type powder supply apparatus which concerns on this invention. It is a fragmentary figure which shows the other example of the backflow prevention structure of the powder in the table type powder supply apparatus which concerns on this invention. It is a schematic plan view of the cut-out disk showing the rotation range of the supply port in the table type powder supply apparatus according to the present invention. It is a timing chart which shows control of the rotational speed (circumferential speed) of the cutting disc in the table type powder supply apparatus which concerns on this invention. It is a figure which shows an example of the relationship between the rotation speed of a cutting disc, and powder supply amount (cutting amount).

Explanation of symbols

1 Hopper 1a Straight body of hopper 2 Table feeder 3 Servo motor (variable speed motor)
3a Position sensor (rotary encoder)
4 Control Panel 5 Lower Casing 5a Upper Flange 5b Discharge Port 6 Cutting Disk 6a Rotating Shaft 6b Supply Port 7 CPU (Control Unit)
8 Servo amplifier (converter)
9 Powder Level Meter 10 Origin Detection Sensor 11 Injection Volume Setting Signal 12 Discharge Line 13 Blower 14 Supply Line 15 Ejector 16 Incinerator Flue 17 Flue Blow Valve 18 Blow Nozzle

Claims (5)

A hopper for storing powder, a table feeder having a cutting disk rotatably disposed in a lower casing at the bottom of the hopper, a top plate covering the top of the cutting disk, and a driving means for driving the cutting disk to rotate With
By rotation of the cutting disc, a powder from the hopper is filled into a plurality of supply ports formed on the outer peripheral edge of the cutting disc at an equiangular pitch and facing an opening formed in the top plate, After the powder filled in the supply port is scraped off by the top plate, the powder is transferred on the lower casing, and the supply port filled with the powder opens to the discharge port formed in the lower casing In the table-type powder supply apparatus configured such that the powder falls to the discharge port by its own weight and is discharged ,
With constituting said driving means at variable speed motor, the rotational speed of the cut disk, when the supply port is located in the scope of supply and / or discharge range of the powder than when located at the other ranges Table type powder supply device characterized in that it is set to be smaller .
  2. The table type powder supply apparatus according to claim 1, wherein the variable speed motor is a servo motor.   The table type powder supply apparatus according to claim 1 or 2, further comprising an origin detection sensor for detecting a position of the supply port. A hopper for storing powder, a table feeder having a cutting disk rotatably disposed in a lower casing at the bottom of the hopper, a top plate covering the top of the cutting disk, and a driving means for driving the cutting disk to rotate With
By rotation of the cutting disc, a powder from the hopper is filled into a plurality of supply ports formed on the outer peripheral edge of the cutting disc at an equiangular pitch and facing an opening formed in the top plate, After the powder filled in the supply port is scraped off by the top plate, the powder is transferred on the lower casing, and the supply port filled with the powder opens to the discharge port formed in the lower casing , A control method for a table-type powder supply device configured such that the powder falls to the discharge port by its own weight and is discharged ,
The rotational speed of the cutting disc when the supply port is located in the powder supply range and / or the discharge range is smaller than that when the supply port is located in a range other than the powder supply range and the discharge range. A control method for a table-type powder supply apparatus, characterized by: setting.
  5. The control method for a table-type powder supply apparatus according to claim 4, wherein the position of the supply port is detected by an origin detection sensor.

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