JPS6130991B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a shelving detection device for a particle moving bed.

Conventionally, in a particle transfer treatment layer where particles are introduced from the top and discharged from the bottom, and chemically and physically treated inside the layer, if the particles inside the layer suffer from a so-called shelf-hanging phenomenon, In terms of time, regardless of the operation of the discharge device, the particles remain in the layer and cannot be discharged, and the voids inside the layer have a negative effect on the processing reaction, and the weight of the upper layer of the voids etc. When the air gap returns and fills, the rapid fluctuation may cause a serious accident to the equipment.Furthermore, if the shelf hanging phenomenon is not detected late and is left unattended, the fixation will strengthen and the equipment will become impossible to return to. This causes various problems such as stopping continuous operation. The occurrence of this shelving phenomenon can be detected by detecting the movement of grains in the layer and stopping the movement, but the conventional methods for detecting grain movement have had various problems. For example, in a method in which a baffle plate is inserted into a particle flow path and the force with which a moving fluid collides with the baffle plate is detected at one or both ends of the baffle plate,
It is difficult to install because the detection mechanism has a driving part and partially closes the flow path.In addition, a hopper is installed at the inlet or outlet of the flow path, and the level of this hopper is detected, and the change in the level is used to detect particles. In the method of detecting body movement, it is necessary to provide a hopper for level measurement, a level detection mechanism, etc., and there is a time delay in detection, and only the average movement of the total amount can be detected, making this method unsatisfactory in practical use. be. Therefore, in general, workers look at changes in the discharge volume at the outlet and make judgments based on experience, but in reality, adverse effects such as increases in outlet temperature and accidents caused by hanging shelves falling occur. This is a condition in which you can only know that a shelf-hanging condition has occurred.

This occurrence was made in view of the above-mentioned problems, and the suspended state was detected by using a particle movement detection means that does not obstruct the flow path of the particles and has a simple structure without a driving part. By providing a device that can detect this at an early stage, it is possible to operate continuously even under critical conditions where shelf hanging is predicted to occur, and by taking measures at the initial stage when shelf hanging occurs, it is possible to prevent serious accidents. This is something that can be avoided.

Specifically, the device for detecting shelving of a grain movement treatment layer according to the present invention uses a capacitance detector that detects movement and rest of grain simply by bringing an electrode into contact with the grain. An electrode is inserted into the upper part of the tank to detect movement and rest of the particles in the upper part of the tank, and at the same time, this detection signal is received as well as a drive signal for the particulate discharge device at the tank outlet, and both signals are added. The present invention is characterized by being equipped with an electric circuit for detecting whether or not the shelf is hanging on the shelf.

Hereinafter, the present invention will be explained in detail with reference to embodiments shown in the drawings.

Reference numeral 1 designates a shaft furnace in which the reaction takes place, 2 a charge hopper installed at the upper part of the shaft furnace 1 via a duct 3, and 4 a furnace lower cutting device installed at the lower end discharge port of the shaft furnace 1, which is driven by a motor 5. ing. The granules 6 charged from the charge hopper 2 move downward while undergoing a reaction in the shaft furnace 1, and are discharged by the cutting device 4.

An upwardly inclined detector mounting duct 8 is branched and provided in the upper part of the particle moving layer 7 consisting of the charge hopper 2, the duct 3, and the shaft furnace 1, that is, in the duct 3 located directly above the shaft furnace 1. , a capacitance detector 9 is attached to the tip of the duct 8 via a flange 10, and a detection electrode 1 of the capacitance detector 9 is attached to the tip of the duct 8.
1 partially protrudes into the branching path, and the flange 1
0 and the peripheral wall of the duct 8.

The capacitance detector 9 compares the amount of change or rate of change in the capacitance value with a predetermined constant value, and transmits a contact signal that turns ON if it is below a certain value, and turns OFF if it is above a certain value. It is connected to the capacitance change detector 12. On the other hand, on the cutting device 4 side, there is provided a drive motor operation detector 13 that emits a contact signal that is ON when the drive motor 5 is in operation and OFF when the drive motor 5 is stopped. The device 12 is connected to a shelf hanging detector 14. The shelf hanging detector 14 has a circuit 14a that adds the signals of both the detectors 12 and 13, and a timer 14b, and the signals received from the detectors 12 and 13 are
When it is ON, a shelving occurrence signal is issued after a certain period of time.

Next, the detection operation in the above device will be explained.

The capacitance of a particle is a constant value when the particle is stationary, but changes when the particle is moving.
Therefore, by measuring the capacitance value at a certain location of the particles and knowing the range of change or rate of change,
It is possible to detect whether the object is stationary or moving. The electrode for detecting this capacitance value only needs to be in contact with the particles, and there is no need to know the absolute value of the capacitance value; only the range of change or rate of change must be below a certain value. It is sufficient to detect whether the value is greater than or equal to the value, and is not affected by changes in the inherent value due to the wetness, shape, etc. of the particles. In this device using a capacitance detector having such characteristics, first, before shelving occurs, the grains 6 begin to move downwards due to the drive of the cutting device, and as shown by the solid line in FIG. The granules 6 come into contact with the tip of 8,
The particles 6 flow down while rotating in contact with each other for movement. Therefore, the arrangement shape of the particles buried between the electrode 11 and the inner circumferential surface of the duct 8 is constantly changing, and the capacitance value changes as shown in FIG. 4 when cut out. This capacitance detector 10
The capacitance signal a detected at
An OFF signal b is transmitted to the shelf hanging detector 14.
On the other hand, since the motor 5 of the outlet cutting device 4 is being driven, the ON signal c is transmitted from the detector 13 to the shelf hanging detector 14. Since the signal b is OFF and the signal c is ON in the shelf hanging detector 14, the addition circuit 1
4a emits an OFF signal d, so timer 1
The output d of 4b is also OFF.

Next, as shown by the chain line in the shaft furnace 1, when shelving occurs, a gap 15 is generated even if the motor 5 is driven and discharges.
Upper particles do not flow downward. When in this state,
At the electrode 11, the particles are deposited up to the maximum angle of repose as shown by the chain line in FIG.
Since the arrangement shape of the particles buried between the inner peripheral surface of the duct 8 and the inner peripheral surface of the duct 8 does not change, the capacitance value does not change much as shown in FIG. When the signal a of the capacitance value is received by the capacitance change detector 12, since the range of change or rate of change of the capacitance value is less than a predetermined value, the ON signal b is detected as hanging. transmits to the device 14. At this time, since the ON signal c is also transmitted from the motor drive detector 13, the signals b and c are both ON in the shelf hanging detector 14, so the timer 14b
After a certain period of time determined by , the shelf hanging detection signal d turns ON and activates the connected alarm or operating device (not shown).

Note that when the discharge device is started, the capacitance value detected by the electrode is constant for a short time until the particles start moving, and the signal b is ON, while the signal c is also ON, but the timer 14b prevents erroneous detection operation.

As is clear from the above description, according to the shelf hanging detection device according to the present invention, the signal of the cutting device drive detector of the discharge section is added to the capacitance detection circuit that detects the movement and rest of the particles. By simply adding a small electrical circuit, it is possible to easily and quickly detect the occurrence of a hanging condition. Therefore, it is possible to perform continuous operation up to the critical condition where shelf hanging is predicted to occur, and in the event of shelf hanging, countermeasures can be taken at an early stage, making it possible to avoid major accidents, etc. It has advantages.

This device can be used not only for granules but also for lumps or powders, and the target equipment is not only a reaction tank but also a simple storage tank, as well as a layer in which the object moves. Needless to say, this also applies to equipment.

In addition to capacitance type detectors, the present invention also applies to detectors that can detect particle movement by changes in measured values, such as electrode current detection type, acoustic detection type, vibration detection type, etc. It is natural that it can be replaced by

[Brief explanation of the drawing]

Fig. 1 is a schematic front view showing an embodiment of the present invention, Fig. 2 is an electric circuit diagram, Fig. 3 is a drawing showing the state of particles in the electrode section, and Fig. 4 is a diagram showing the electrostatic charge during movement of the particles. FIG. 3 is a diagram showing changes in capacitance value. 1...Shaft furnace, 2...Charge hopper,
4... Cutting device, 5... Motor, 6... Particles,
7...Particle movement layer, 9...Capacitance detector, 11
...Electrode, 12...Capacitance change detector, 13...
...Motor drive detector, 14...Shelf hanging detector.

Claims (1)

[Claims] 1. In a particle movement layer in which particles are supplied from the upper part and discharged by driving a discharge device in the lower part, the electrostatic charge of the particles is reduced by an electrode inserted in the upper part of the particle movement layer. A capacitance detector that detects a capacitance value; and a capacitance change detector that generates a signal by comparing the change or rate of change of the capacitance value detected by the capacitance detector with a preset constant value. and a shelving detector that generates a shelving occurrence signal by adding the signal from the capacitance change detector and the drive signal of the discharge device, and a shelving detector for generating a shelving occurrence signal. Device.