JP3004964B2 - Rotary feeder clearance automatic adjustment method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for automatically adjusting a gap between a rotor and a casing of a rotary feeder used for fixed-rate feeding of a granule in a pneumatic transportation of the granule when the gap disappears.

[0002]

2. Description of the Related Art In the industries such as chemistry and steelmaking, various kinds of powders are handled as materials and products, and pneumatic transportation is used as a means of transporting powders. In the pneumatic transportation device, a rotary feeder is used to send out a granular material from a silo, a hopper or the like to a transportation pipeline in a fixed amount.

[0003] In the rotary feeder, generally, a rotor having a plurality of blades arranged radially rotates in a cylindrical casing, and powders falling from an upper hopper are packed between the blades and rotated. It is structured to drop from the outlet.

When this rotary feeder is used, for example, as a mixing machine of a pneumatic transporting apparatus, the pressure in the transport pipe is cut off and the powder is dropped by gravity. It is valued.
For this reason, the gap between the rotor and the casing is preferably as small as possible. However, if the gap is too small, the rotation resistance becomes excessively large due to the entrapment of the powder and the particles and the thermal expansion of the rotor. Therefore, to safely rotate the rotary feeder, a gap of about 0.1 to 0.3 mm is usually provided on average.

[0005] In recent years, the quality of transported goods in pneumatic transportation has been required to be improved by measures such as measures against crushing and abrasion, and reduction in the amount of irregularly shaped articles. As a countermeasure, a high-pressure transport system with low wind speed and high concentration flow has been actively adopted. A compressor is mainly used as a pressure source for the high-pressure transport system, and an operation power of about 6 kW or more per 1 m ³ / min is required.

In order to reduce power loss in a high-pressure air transport device, there is a need for a rotary feeder with less leakage of high-pressure air. To reduce the air leakage from the rotary feeder, the smaller the gap between the casing and the rotor is, the better, but there is a limit to reducing the gap to avoid the risk of burning due to contact between the casing and the rotor. .

[0007] The rotary feeder is designed to ensure safe operation. However, depending on conditions such as high-temperature operation and high differential pressure operation, seizure may occur due to contact between the casing and the rotor, or failure may occur due to the intrusion of foreign matter. Or inoperability may occur.

Hitherto, in order to prevent such a seizure accident, a method of attaching a soft metal or plastic chip to the blade edge of the rotor has been adopted. In addition, in the event of a burn-in accident or a foreign matter entrapment accident, the rotary feeder was removed from the facility, disassembled, and the burnt-in part was ground and repaired.

There is a rotary valve provided with a rotor moving device on a tapered rotor in order to remove a foreign substance that has caught between the casing and the rotor without disassembling the device (Japanese Utility Model Publication No. 59-11946). In addition, to facilitate maintenance and inspection of the rotary feeder,
There is a rotary valve provided with a detachable device on a rotor so that the rotor can move forward and backward with respect to a fixed casing, and retreats at the time of inspection to automatically disassemble the rotor (JP-A-6-1017).
No. 71).

[0010]

As described above, the conventional automatic detection device is designed to remove the foreign material that has caught between the casing and the rotor without disassembling the device when a failure occurs due to the foreign material being caught. The abnormal torque detecting device detects that the rotor has become unable to rotate due to the biting, moves the rotor, enlarges the gap between the casing and the rotor, and removes foreign matter. However, this device only returns the rotor to its original state after removing the biting foreign matter, and does not adjust the gap between the casing and the rotor.

According to the present invention, in view of the above-mentioned conventional situation, in order to reduce air leakage, a rotary feeder operating with a clearance between a casing and a rotor as small as possible is used to reduce fluctuations in system temperature, air temperature and temperature. The casing and rotor are distorted due to the effect of changes in the outside temperature due to changes in the environment such as wind and rain. When the casing and the rotor come into contact and the gap disappears, the contact is detected and the gap is automatically corrected. It is an object of the present invention to provide a method for automatically adjusting a gap between rotary feeders.

[0012]

Various means can be considered as means for detecting the contact between the casing and the rotor in the rotary feeder. However, in the method using laser or light, since the granular material is clogged in the machine,
Cannot receive. In the method of detecting the amount of runout of the rotor shaft, the amount of thermal expansion displacement of the rotor or the casing cannot be measured. In the case of the needle-contact type in which the displacement of the rotor is measured from the casing, abrasion due to a handled object occurs, and accurate detection cannot be performed. In the method using sound, it is difficult to distinguish the sound from a metallic sound or the like generated when the object rotates while holding the object. In the method of detecting the contact by the fluctuation of the motor power, it is difficult to distinguish the power from the power at the time of starting or at the time of rotating by biting an object to be handled. Therefore, the present inventor considers that it is best to adopt a method in which the entire casing and rotor in the rotary feeder function as a sensor as contact detection means,
Based on this idea, a method for automatically adjusting the gap of the rotary feeder was completed as follows.

A rotor in which a plurality of tapered blades are radially arranged on a rotating shaft is electrically insulated from a fixed casing, and a predetermined length range necessary for gap adjustment in the axial direction is adjusted by driving an adjusting motor. It is intended for rotary feeders that can be reciprocated and combined. Then, a contact detection electric circuit capable of detecting the contact between the rotor and the casing by the flow of the weak voltage / current is formed between the rotor and the casing. Upon receiving a contact detection signal from the contact detection electric circuit, the drive motor for driving the rotor is immediately stopped, and the adjustment motor is rotated by a predetermined amount or driven for a predetermined time to move the rotor toward the rotor large diameter side. . Thereby, the contact between the rotor and the casing is eliminated, and at the same time the gap is adjusted.

In the method for automatically adjusting the clearance of the rotary feeder, one end of the rotating shaft of the rotor is electrically insulated to the casing side plate so as to be slidable in the axial direction by a non-conductive packing material and a bearing. A non-conductive gear made of synthetic resin having a large width and supported at the shaft end is engaged with the drive gear of the drive motor. The other shaft end is rotatably and axially slidably slidably fitted to the casing side plate by a non-conductive packing material, and a thrust bearing provided at the shaft end is screwed to the casing side plate. A rotary feeder is used, which is attached to the inner hole of a wide synthetic resin non-conductive gear screwed in such a way that the synthetic resin gear can be moved forward and backward, and the synthetic resin gear is engaged with the drive gear of a gap adjustment motor.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the rotary feeder shown in FIG. 1, a detection signal transmitter is provided in a contact detection electric circuit in which a weak voltage / current flows when a rotor comes into contact with a casing. In addition, the weak voltage / current refers to the one conforming to the intrinsically safe explosion-proof structure of the electric machine appliance explosion-proof structure standard.

As shown in FIG. 3, if the gap between the casing and the rotor is to be increased from the current state by δ = 0.05 mm, for example, when the taper degree of the rotor θ = 3 °, the rotor moves once. The distance L is L = δ {sin θ = 0.05}
At sin3 °, it is about 0.955 mm. Therefore,
The amount of operation of the gap adjusting motor is determined in one operation according to conditions such as the capacity of the rotary feeder and the size of the material to be handled. That is, the number of rotations or driving time of the adjustment motor is determined from the amount of the gap to be adjusted.

When the rotor comes into contact with the casing during operation, the contact detection electric circuit is closed and current flows.
Then, the power of the drive motor is turned off by the detection signal from the detection signal transmitter, and the rotation of the rotor is stopped. At the same time, the power of the gap adjusting motor is turned on, the motor rotates by a predetermined amount, and the rotor moves a set length in the direction of the larger diameter of the rotor to adjust the gap between the casing and the rotor. Then, after the adjusting motor rotates a predetermined amount or after a predetermined time has elapsed, the power is turned off and stopped. At the same time, the power of the driving motor is turned on, the rotor is started again, and the operation of the rotary feeder is restarted.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An automatic clearance adjusting method according to the present invention electrically insulates a rotor 1 having a plurality of tapered blades radially arranged on a rotating shaft 2 with respect to a fixed casing 3 shown in FIGS. A case will be described in which a fixed length range necessary for gap adjustment in the axial direction is reciprocated by driving the adjustment motor 6 and is implemented using a combined rotary feeder.

In FIG. 1, one shaft end of a rotating shaft 2 of a rotor 1 is slid in the axial direction by a non-conductive packing material 2c and a bearing 2a having a Teflon sheet interposed between the shaft and an inner ring. It is electrically insulated and supported on the casing side plate 4a of the casing 3 freely. The bearing 2a is fixed to the casing side plate 4a by the holding lid 4c. A wide synthetic resin non-conductive gear 5b provided at the shaft end is connected to the drive motor 5
With the drive gear 5a. The other shaft end is rotatably and axially slidably slidably fitted to the casing side plate 4b by a non-conductive packing material 2c. Then, the thrust bearing 2b provided at the shaft end is attached to the inner bottom of the inner hole 6c formed in the wide synthetic resin non-conductive gear 6b. The non-conductive gear 6b is screwed into a screw portion 7 provided between the non-conductive gear 6b and the casing side plate 4b, and is provided so as to be able to advance and retreat in the axial direction by rotation of the gear. The non-conductive gear 6b meshes with a drive gear 6a of an adjustment motor 6 for adjusting a gap between the rotor 1 and the casing 3. A rotary connector 8 is provided at a shaft end of the rotating shaft 2 on the side supported by the thrust bearing 2b as a rotor-side contact for a contact detection electric circuit. Further, the casing side contact is provided at an arbitrary position.

In the contact detection electric circuit, when the rotor 1 and the casing 3 come into contact with each other, a weak voltage current flows by closing the circuit, and the drive motor 5 receives a detection signal of a detection signal transmitter provided in the circuit. Any circuit can be used as long as the configuration is such that the adjustment motor 6 is stopped and rotates at a predetermined number of rotations, or rotates for a predetermined fixed time.

The amount of the gap to be adjusted is determined by conditions such as the capacity of the rotary feeder and the size of the material to be handled.
Therefore, the rotation speed or rotation time of the adjustment motor is calculated in advance based on the gap amount.

When the rotary feeder is driven by driving the drive motor 5 in a state where there is a regular gap between the rotor 1 and the casing 3, the power of the drive motor 5 is transmitted from the drive gear 5a to the non-conductive gear 5b. Rotation axis 2
Rotates. During this operation, the rotor 1
And the casing 3 come into contact with each other. FIG. 1 shows this state. At this time, as shown in FIG.
Is closed, a detection signal is transmitted from a detection signal transmitter 11 provided in the circuit, and after the drive motor 5 stops, the adjustment motor 6 for gap adjustment rotates. The rotation of the adjusting motor 6 is transmitted from the driving gear 6a to the non-conductive gear 6b. Then, the engagement of the screw portion 7 moves in the detaching direction due to the rotation of the non-conductive gear 6b. This movement causes the rotating shaft 2 to move in the direction toward the large diameter side of the rotor (to the left in FIG. 2). Then, if the adjustment motor 6 is rotated a predetermined number of times or stopped after a predetermined time has elapsed, a predetermined gap is formed between the rotor 1 and the casing 3 as shown in FIG. Here, the drive motor 5 is started to restart the operation of the rotary feeder.

[0023]

According to the clearance adjusting method of the present invention, the rotation of the rotor is stopped at the same time when the rotor comes into contact with the casing.
Further, since the rotor is moved to secure a predetermined gap, seizure due to contact of the rotor can be prevented, and the operation efficiency of the rotary feeder can be improved.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an example of a rotary feeder used for carrying out the present invention, in a state where a rotor and a casing are in contact during operation.

FIG. 2 is a cross-sectional view showing a state in which a gap between a rotor and a casing has been adjusted by rotation of an adjustment motor from the state of FIG. 1;

FIG. 3 is an explanatory diagram showing a relationship with a single moving distance L of a rotor when a gap of a taper degree θ between a rotor and a casing is increased by δ mm from the current state.

FIG. 4 is a block diagram illustrating an example of a procedure of a gap adjusting method according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rotor 2 Rotating shaft 2a Bearing 2b Thrust bearing 2c Packing material 3 Casing 4a, 4b Casing side plate 4c Pressing lid 5 Drive motor 5a Drive gear 5b Non-conductive gear 6 Adjustment motor 6a Drive gear 6b Non-conductive gear 6c Inner hole 7 Screw Part 8 Rotary connector 9 Contact detection electric circuit 10 Rotary feeder 11 Detection signal transmitter

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B65G 65/30-65/48 B65G 53/00-53/28 B65G 53/32-53/66

Claims (2)

(57) [Claims] 1. A rotor in which a plurality of tapered blades are radially arranged on a rotating shaft with respect to a fixed casing is electrically insulated, and can be reciprocated by driving an adjusting motor within a fixed length range in the axial direction. In the combined rotary feeder, a contact detection electric circuit for detecting the contact between the rotor and the casing by the flow of the weak voltage and current is formed, and when a contact detection signal is received from the contact detection electric circuit, the rotor operation is immediately performed. Automatic adjusting method of a rotary feeder for stopping a driving motor for use and for moving the rotor in the direction of the larger diameter of the rotor by driving the adjusting motor so as to eliminate the contact between the rotor and the casing and simultaneously adjust the gap. . 2. A shaft end of one of the rotating shafts of the rotor is electrically slidably and axially slidable in the axial direction by a non-conductive packing material and a bearing, and is electrically insulated from the casing side plate. The wide non-conductive gear made of synthetic resin is engaged with the drive gear of the drive motor, and the other shaft end is electrically connected to the casing side plate by a non-conductive packing material so as to be rotatable and slidable in the axial direction. And a thrust bearing provided at the shaft end is attached to the inner hole of a wide synthetic resin gear screwed into the casing side plate by a screw so as to be able to advance and retreat. 2. The method for automatically adjusting the gap of a rotary feeder according to claim 1, wherein a rotary feeder meshed with a driving gear of a gap adjusting motor is used.