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Gravimetric blender coal feeder automatic booster manufacturing method


source:[Gravimetric blender]   release time:2021-04-15 09:33:53




In order to overcome the shortcomings of the existing weighing metering coal feeder and improving the adaptability of the weighing metering coal feeder, the Gravimetric blender solves the problem of blockage of large coal blocks at the bottom of the feed inlet of the weighing metering coal feeder. An automatic coal feeding device for weighing coal feeder is provided.
The purpose of the present invention is achieved in this way, a weighing type metering coal feeder automatic coal feeding device, the device includes a feed barrel, the upper axial direction of the feed barrel is provided with a feed inlet, the The radial side wall of the feeding bucket is provided with a discharge port, and the opening direction of the discharge port faces the running direction of the coal feeder belt. On the side wall of the feeding bucket, both sides of the discharge port are fixed Two bearing seats, each bearing seat is provided with a bearing, the two bearing seats are provided with a booster shaft, one end of the booster shaft is connected to a variable frequency motor through an overrunning clutch and a reducer, and the other of the booster shaft A proximity switch sensor block with four protrusions crosses in the circumferential direction at one end, a proximity switch bracket is fixed on the bearing seat on the side close to the proximity switch sensor block, and a proximity switch is fixed on the proximity switch bracket. The proximity switch corresponds to the raised proximity switch induction block; the middle part H of the booster shaft (the part between the two bearings) has a diameter-reducing structure symmetrically from the outside to the inside, and the diameter changes from large to small from outside to inside. The middle part H is provided with annular crushing teeth in order from the outside to the inside along the axial direction.
Gravimetric blender coal
The advantages and technical effects of the present invention are:

1. The device of the present invention is mainly installed at the exit of the feed inlet of the weighing type metering coal feeder. When the feed inlet of the weighing type metering coal feeder is jammed by large coal, the automatic coal feeding device can monitor The jam at the entrance will be handled automatically.

2. The power-assisted shaft of the automatic coal feeder of the present invention is designed with a special shape and has a crushing function. Under the action of the rolling force of the power-assisted shaft and the friction force of the belt of the original weighing coal feeder, the For the squeezing and crushing of lump coal, the device can have a good crushing ability for coal lump 1.2 times the size of the raw coal through experiments.

3. The device of the present invention has a simple structure, draws on the principle of a counter-wheel pulverizer, and can crush super-large coal and frozen blocks. The device has been successfully tested in Jidian Siping No. 1 Thermal Power Company.

4. The present invention also has the following advantages: ①Automatically detects the jam of the feed pipe and performs automatic processing; ②It can be connected with the original coal cut signal of the coal feeder, with high reliability; ③The booster shaft is optimized and has good crushing Effect; ④The power assist time can be set by yourself; ⑤There is a manual execution device, which can manually assist in handling the jam at the feeding pipe.

Marking: feed barrel 1, feed port 1-1, discharge port 1-2, bearing seat 2, bearing 3, booster shaft 4, proximity switch induction block 4-1, annular crushing tooth 4-2, overrunning clutch 5 , Reducer 6, frequency conversion motor 7, proximity switch bracket 8, proximity switch 9.

Detailed ways
Gravimetric blender
Shown by 1, 2, 3, and 4: a weighing-type coal feeder automatic booster device for coal, the device includes a feeding barrel 1, the upper axial direction of the feeding barrel 1 is provided with a feeding Port 1-1, the radial side wall of the feed barrel 1 is provided with a discharge port 1-2. The opening direction of the discharge port 1-2 faces the running direction of the coal feeder belt. Two bearing seats 2 are fixed on both sides of the discharge port 1-2 on the side wall of the barrel 1, and each bearing seat 2 is provided with a bearing 3, and the two bearing seats 2 are provided with a booster shaft 4 One end of the booster shaft 4 is connected to a variable frequency motor 7 through an overrunning clutch 5 and a reducer 6, and the other end of the booster shaft 4 crosses in the circumferential direction with four protruding proximity switch induction blocks 4-1. A proximity switch bracket 8 is fixed on the bearing seat 2 on the side close to the proximity switch sensing block 4-1, and a proximity switch 9 is fixed on the proximity switch bracket 8, and the proximity switch 9 corresponds to the raised proximity switch sensing block 4 -1 setting; the middle part H of the booster shaft 4 (the part between the two bearings 3) is a symmetrical diameter reducing structure from the outside to the inside, and the diameter from the outside to the inside decreases from large to small, and the middle part H is along the axis Ring-shaped crushing teeth 4-2 are sequentially arranged from the outside to the inside.

working principle:
The working process of automatic coal feeding device: coal hopper→feeding port→power-assisted shaft→coal feeder belt→discharge port→coal pulverizer.

Shown in 5: The automatic coal feeder is installed at the bottom of the feeder 1-2 of the feeder barrel 1, and the coal feeder belt carries the coal falling from the feeder 1-1 to move in the direction indicated by the arrow. Promote the power-assisted shaft 4 to rotate. When the coal block is large enough, the power-assisted shaft 4 is blocked by the coal block and stops rotating. The proximity switch 9 no longer sends out a pulse signal indicating the rotation of the main shaft. The variable frequency motor 7 is started via the control loop linkage interlock. Running at the set time, the variable frequency motor 7 drives the assist shaft 4 to rotate through the reducer 6 and the overrunning clutch 7, and the resultant force of the coal feeder belt after the excessive coal is crushed by the annular crushing teeth 4-2 on the assist shaft 4 Under the action of the discharge port 1-2, when the set time is reached, the frequency conversion motor 7 stops working, the overrunning clutch 5 is disengaged, and the normal coal flow pushes the power-assisted shaft 4 to rotate and drives the four proximity switch sensing blocks 4-1 on the power-assisted shaft 4 Rotate, cooperate with the proximity switch 9 to output a pulse signal. After the control loop detects the pulse signal, the variable frequency motor 7 is placed in a standby state and waits for the next cycle of processing the blockage of large coal.
As shown in 1, 2: The power-assisted shaft 4 is the core component of the automatic coal feeding device. The material of the power-assisted shaft 4 is alloy steel or cast carbon steel with high strength and wear resistance. Annular crushing teeth 2-1 are sequentially processed in the axial direction from the outside to the inside.

The proximity switch control loop and DCS logic principles 6 and 7 of the present invention are as follows:
The proximity switch 9 uses an AC 220V inductive proximity switch (the example model is Wisneman w415kcx). The working power supply AC220V is taken from the local control cabinet of the coal feeder, and an intermediate relay 1ZJ is installed in the control cabinet (as shown in Figure 6). Show), when the booster shaft rotates, the proximity switch 9 detects the induction block 4-1 to excite the intermediate relay 1ZJ. The relay normally open passive contact 1ZJ1 is sent to the DCS system DI card as the assist axis detection signal. The compiled logic is shown in Figure 7. The assist axis detection signal is frequently closed/disconnected during normal operation. When the DCS system is within XX seconds (example Set to 7 seconds) When the detection signal is always on or off, it is judged that the booster shaft has stopped rotating, and an alarm message is sent out. At the same time, the signal is output to the variable frequency motor through the DO card, and the variable frequency motor is interlocked to break the coal lump. After the variable frequency motor is started, it will automatically stop after the logic timer T(s) (the example is set to 30 seconds).
Glossary:
DCS system: DCS is the English abbreviation of Distributed Control System (Distributed Control System), which is also called Distributed Control System in the domestic automatic control industry. The so-called distributed control system, or in some materials called the distributed system, is a new type of computer control system relative to the centralized control system. It is developed and evolved on the basis of the centralized control system. Coming. It is a multi-level computer system composed of process control level and process monitoring level with communication network as the link. It integrates 4C technologies such as computer, communication, display and control. Its basic idea is decentralized control, centralized operation, hierarchical management, Flexible configuration and easy configuration. DCS is widely used in centralized control systems for power plants.
Variable-frequency motor: Variable-frequency variable-speed motor is abbreviated as variable-frequency motor. It is a general term for motors driven by frequency converters. The advantage is that it has a starting function; electromagnetic design reduces the resistance of the stator and rotor; adapts to frequent variable speeds under different working conditions; Energy-saving to a certain extent has now become the mainstream speed regulation scheme, which can be widely used in continuously variable transmissions in all walks of life. (Sample project uses vector inverter)
When the instantaneous coal supply amount and the cumulative coal supply amount, the calculus regulator calculates the coal supply amount at the same time, this coal supply signal and the pre-set coal supply signal or the coal supply signal required by the boiler combustion control system Comparison: After adjusting according to its deviation, the speed at which the motor should run is obtained. By changing the speed of the main motor to change the conveying speed of the metering conveyor belt, the actual coal feed amount is the same as the required coal feed amount to meet the boiler load. Claim.
However, the existing Gravimetric blender coal feeder does not have an automatic coal feeding device. When the coal hopper has large frozen coal or excessively large coal, it will jam at the bottom of the feeder of the coal feeder and affect the coal feeding of the boiler. The normal operation of the coal feeder must be manually removed after the jammed coal lump can be restored to the normal operation of the coal feeder.[Gravimetric blender]