KR100674580B1 - Auto variable speed controlling apparatus of centrifuge - Google Patents

Abstract

The present invention outputs the vehicle speed control value to the inverter through the vehicle speed braking current value input according to the concentration of the sludge injected and the solid discharge pressure, and the inverter controls the vehicle speed motor through the vehicle speed control value to discharge the solids of the desired properties. The present invention relates to an automatic vehicle speed proportional control device of a sludge centrifuge, which inputs a load current value applied to a vehicle speed motor according to an inverter and a sludge concentration electrically connected to the vehicle speed motor and a solid discharge pressure. The load current value is compared with the preset range of the sludge concentration, the solid discharge pressure, and the braking current according to the transfer torque, and the vehicle speed control value is output to the inverter, and the inverter outputs the vehicle speed motor according to the vehicle speed control value. A vehicle speed controller configured to proportionally control the current value. It is characterized by.

 Centrifuge, inverter motor, feedback, sludge

Description

Auto variable speed controlling apparatus of centrifuge

1 is a block diagram of a centrifuge according to the present invention.

2 is an automatic speed proportional control system diagram of a centrifuge according to the present invention.

Figure 3 is a graph of automatic vehicle speed proportional control of another centrifuge according to the present invention.

<Explanation of symbols for the main parts of the drawings>

18: vehicle speed motor 31: inverter

40: vehicle speed controller

The present invention relates to a centrifuge that separates sludge by controlling a vehicle speed motor with an inverter. More specifically, the vehicle speed control value is converted into an inverter through a vehicle speed braking current value input according to the concentration of sludge and solid discharge pressure. And an automatic vehicle speed proportional control device of a sludge centrifuge which outputs and enables the inverter to control the vehicle speed motor through the vehicle speed control value to obtain an exhaust solid of a desired property.

In general, the removal of solids contained in manure, livestock wastewater, sewage, and wastewater flows into the inlet, removes coarse contaminants by applying various types of screens, and then enters into a screw press, which contains fine solids. The filtrate is solidified into sludge through several water treatment processes and remains in the water.

In addition, since the sludge groups generated in the water treatment process are generated with various properties and properties, various types of sludges are collected in one place to be treated in the generating process and the collection storage tank to reduce the moisture contained in the solids. Although dehydration is performed using a dehydrator, there are problems such as installation area, installation cost, automation, maintenance, etc., in the treatment of sludge that is unevenly generated, such that a lot of restrictions on automated operation are followed.

In addition, in the conventional decanter centrifugal condenser and dehydrator operation control, the centrifugal condenser operation is a direct operation control. The concentration of the sludge discharged is adjusted by adjusting the concentration of the sludge discharged in the bowl by adjusting the concentration of the concentrated sludge discharge. It was a way of adjusting.

At this time, the operation control of the decanter is to install a densitometer at the concentrated sludge discharge stage, detect the concentration deviation applied to the current by braking with a differential electric motor, and brake the wheel shaft connected to the gearbox by the torque applied to the screw conveyor. There are two types of eddy current braking differential speed control method to adjust and a differential speed braking by hydraulic device consisting of oil tank and hydraulic pump by detecting conveyor torque inside the bowl by adjusting rotation by braking by hydraulic device. .

The centrifugal dehydrator detects screw torque and adjusts the set value and detection deviation set in the control device to PID calculation value, and operates the back drive motor through the current conversion inverter control unit to continuously control to the set target value for continuous operation. That's the way.

However, the screw torque detection control method and the discharge sludge concentration detection control method as described above should be provided with a separate machine detection device, additional equipment such as PID, PLC electronics and program configuration, and a safety circuit breaker or an overload safety device. While manufacturing costs are high, many problems arise as far as precision and stable automatic control operation is concerned.

The present invention has been made to solve the above problems, and outputs the vehicle speed control value to the inverter through the vehicle speed braking current value input in accordance with the concentration of the sludge to be injected and the solid discharge pressure, and the inverter through the vehicle speed control value It is an object of the present invention to provide an automatic vehicle speed proportional control device of a sludge centrifuge which controls a vehicle speed motor to obtain a discharge solid of a desired property.

In addition, to provide a decanter-type centrifuge having a relatively low manufacturing cost without the need for a separate safety circuit breaker or overload safety device.

The configuration of the present invention devised to achieve the above object is as follows. According to the present invention, a screw conveyor is installed in the outer bowl, and the main bowl and the speed motor are installed in the outer bowl and the screw conveyor to rotate the outer bowl and the screw conveyor, and the outer bowl and the screw are installed through the inverter. In the centrifuge for separating and discharging sludge into the external bowl by discharging the sludge into the outer bowl by rotating the conveyor, the concentration of the sludge and the discharge of the sludge electrically connected to the inverter and the vehicle speed motor The load current value applied to the vehicle speed motor is input from the inverter, and the load current value is judged by comparing with the set range of the braking current according to the preset sludge concentration, the solid discharge pressure, and the conveying torque, and outputs the vehicle speed control value to the inverter. Vehicle speed controller that allows the inverter to proportionally control the vehicle speed motor according to the vehicle speed control value. Characterized in that it comprises a controller.

Here, the inverter is characterized in that the surplus eddy current consumed by driving the vehicle speed motor through the internal braking resistor is applied to the regenerative electricity to the inverter of the main motor.

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention will be described in detail.

1 is a block diagram of a centrifuge according to the present invention, FIG. 2 is a schematic diagram of an automatic vehicle speed proportional control of a centrifuge according to the present invention, and FIG. 3 is a graph of an automatic vehicle speed proportional control of another centrifuge according to the present invention.

As shown, the centrifugal separator according to the present invention is rotatably supported by the outer movable ball (3) to the bearing on both sides of the upper side of the base frame (2,2a) fixed to the ground by the dustproof parts (1, 1a) The drive pulley 5, which is connected to the drive motor 4 and the belt, is assembled to the main rotating shaft, and the bowl driving pulley 6 and the braking pulley 5 are connected to rotate in the same direction.

In addition, a screw conveyor (8) for transporting solids is mounted on the inner circumference of the cylindrical outer bowl (3) so as to communicate with the feed liquid pipe (7), and at a predetermined portion of the screw conveyor (8), the feed is ejected along the circumference. The feed liquid outlet 9 is formed so as to be through the inside.

A solid discharge bushing 10 is formed at the conical inclination angle of the outer bowl 3, and the outer bowl 3 is supported by the base frames 2 and 2a while being protected by the outer casing 11, and the casing ( On both sides of the bottom of the 11) the separation liquid outlet 12 and the solid discharge port 13 is formed.

On the other hand, one side of the outer bowl (3) is formed with a dam flange 14 for discharging the separation liquid, the screw conveyor (8) is connected to the gearbox output shaft 15, the output shaft is again passed through the gearbox (16) The brake pulley 17 is connected to the center gear shaft arm, and the vehicle speed motor 18 is installed under the gear box 16. The differential pulley 19 and the brake pulley 20 are connected to the brake input belt 21 on the shaft. Through the differential pulley 17 and the braking pulley 6, respectively.

The operation of the centrifuge is described as follows.

In the operation process of the centrifuge according to the present invention, when power is supplied to the driving motor 4, the outer bowl 3 rotates at a constant speed of the set rotation ratio of the driving pulley 5 to generate centrifugal force and at the same time screw conveyor. (8) is supported by a bearing in the outer bowl (3) is connected to the gearbox output shaft (15) and the gearbox (16) in conjunction with the braking pulley (17) on the center gear shaft, the differential pulley (17) Try to rotate at the rotational speed of the outer bowl (3).

At this time, when the vehicle speed controller 40 transmits the vehicle speed control value to the inverter 31 through a feedback process, and the inverter 31 applies a braking current according to the vehicle speed control value to the vehicle speed motor 18, the external bowl 3 ) And the rotational difference between the screw conveyor 8 is obtained.

That is, the differential pulley 17 does not generate a forward rotation load, but is subjected to a reverse rotation braking load such that the screw conveyor 8 rotates later than the rotation speed of the outer bowl 3.

Here, the vehicle speed represents the number of revolutions of the solids conveyance of the screw conveyor 8 on the basis of the outer bowl 3, and the calculation formula is as follows.

Vehicle speed = (outer bowl speed-differential pulley speed) ÷ gearbox reduction ratio
That is, as the differential difference between the outer bowl 3 and the screw conveyor 18, the differential pulley 17 is subjected to a reverse braking load, and after subtracting the differential pulley rotation speed from the outer bowl rotation speed, these storage boxes By dividing by the reduction ratio, the above-mentioned vehicle speed can be obtained.
This can be easily carried out by those skilled in the art in the field of centrifuges, so the detailed description thereof is omitted here.

In this state, the feed flows into the feed liquid outlet 9 of the screw conveyor 8 which is operated in the forward rotation through the feed liquid pipe 7, and is distributed in the outer bowl 3 by the centrifugal force of the outer bowl 3 which is dispersed and rotated. Are separated into light supernatant and heavy solids.

Here, the light supernatant flows into the outer bowl 3 and flows through the helical channel of the screw conveyor 8 to overtake the dam flange 14 on the side of the outer bowl 3 so as to separate the outlet of the separating casing 11 of the outer casing 11. 12) the separation liquid is discharged to the outside, and the heavy solids are moved toward the inclined angle by the screw conveyor 8 which is settled out of the outer bowl 3 and rotates and is moved by the centrifugal force and the pressing force of the screw conveyor 8. It is concentrated and dehydrated and discharged through the solid outlet 13 of the outer casing 11.

Here, the vehicle speed should be changed automatically according to the solid concentration change of the input feed to obtain the desired concentration of the discharged solid in the concentration and dehydration process. Concentrates of discharged solids are generated, and the dehydration process maximizes the concentration of discharged solids to reduce the amount of discharged solids to be disposed of last, thereby reducing the cost of incineration, landfill, and dumping.

On the other hand, if the concentration of the solids supplied is constant, the desired velocity of the concentrated and dehydrated solids can be continuously obtained while the vehicle speed is fixed, but the sludge generated in the wastewater treatment process is characterized by the characteristics of the process, season, time, operating method, etc. As a result, the concentration of solids in the sludge changes frequently.

In this way, even if the concentration of the feed is changed, the vehicle speed is adjusted so as to stably obtain the discharged solids. If the vehicle speed is small, the settled solids have a longer residence time in the outer bowl 3, resulting in a higher concentration of the discharged solids. If it is large, the settled solid uses a principle that the concentration of discharged solid is lowered due to less residence time in the outer bowl (3).

In other words, if the concentration of the feed is high at a constant flow rate of the feed, the sedimented solids accumulate therein, so that the vehicle speed is increased, and if the concentration of the feed is low, the vehicle speed is decreased to obtain the discharge solid concentration of the desired property.

The centrifuge according to the present invention is provided with a separate vehicle speed controller 40 to adjust the vehicle speed to obtain the discharge solids concentration of the desired properties.

Referring to the feedback control table according to the inverter 31 and the vehicle speed controller 40 is as follows.

Vehicle speed control value input table according to load current value Current input value Output terminal Step setting value Step output Vehicle speed (hz) One 2 3 4 No-load current value 0 Equal to or less than Step1 - - - - No-load setting frequency 1 load current One When larger than Step1 value ON - - - Input load frequency 2 load current 2 When larger than Step2 value - ON - - Input load frequency 3 load current 3 When larger than Step3 value ON ON - - Input load frequency 4 load current 4 When larger than Step4 value - - ON - Input load frequency 5 load current 5 When larger than Step5 value ON - ON - Input load frequency 6 load current 6 When larger than Step6 value - ON ON - Input load frequency 7 Overload input stop 7 When larger than Step7 value ON ON ON - Overload crackdown Overload stop 8 When larger than Step8 value - - - ON Safe driving signal

The vehicle speed controller 40 is to control the rotational speed of the vehicle speed motor 18 as described above to obtain a solid concentration of the desired properties, which is the outer bowl (see the differential pulley 17 connected to the vehicle speed motor 14). It is to rotate at a slower speed than 3).

To this end, the vehicle speed controller 40 rotates the vehicle speed motor 18 by controlling the inverter 31 according to the load current value transmitted from the analog output terminal of the inverter 31, and the control of the inverter 31 is shown in Table 1 below. As shown, the load current value transmitted from the inverter 31 is compared with the preset Step current value and the rotation speed of the vehicle speed motor 14 is commanded to the function selection terminal of the inverter 31 according to the magnitude.

Here, the step current value refers to the setting range of the braking current according to the concentration of the sludge, the solid discharge pressure and the conveying torque set in the vehicle speed controller 40.

Referring to Table 1, the vehicle speed controller 40 outputs the vehicle speed control value through four analog output terminals according to the load current value output from the inverter 31. For example, the input load current value is set as a step setting value. Compared to, if all output terminals 1, 2, 3, 4 are less than or equal to Step1 setting value, all output terminals 1, 2, 3, 4 are turned off. This process consists of 9 steps in total and the vehicle speed control value corresponding to each step is output as described above.

In this way, the inverter 31 outputs the above nine steps as shown in Table 1 to the output terminals 1, 2, 3, and 4 as ON or OFF by comparing the load current value with the preset Step current value. The vehicle speed motor 18 is controlled at the frequency as shown in FIG. 3 according to the vehicle speed control value corresponding to the ON or OFF of the output terminals 1, 2, 3 according to the load current from the controller 40. This process is repeated continuously until the sludge concentration, the solid discharge pressure and the rotational speed corresponding to the conveying torque.

The braking current application process according to the load current and the load current through the vehicle speed controller 40 will be described.

In the differential motor 18, the driving power generated in the outer copper bowl 3 generates a braking load while the solids settled on the inner surface of the outer copper bowl 3 are caught by the blades of the screw conveyor 8, and the outer copper bowl 3 ), The driving force to be rotated is decelerated and braked in the gearbox 16 primarily.

That is, the driving power is transmitted to the differential pulley 17 by the braking belt from the braking pulley 20 connected to the sun gear protruding from the gear box 16, and the rotation braking and load current of the differential motor 18 31 is transmitted to the vehicle speed controller 40, and the vehicle speed controller 40 transmits the vehicle speed control value to the inverter 31.

Accordingly, the inverter 31 applies the braking current to the vehicle speed motor 18 according to the vehicle speed control value input from the vehicle speed controller 40.

On the other hand, the braking current for driving the vehicle speed motor 18 is consumed in the vehicle speed motor 14, the surplus eddy current of the vehicle speed motor 18 is transmitted to the main motor inverter through the braking resistor of the inverter 31 to regenerate the main motor It is applied by electricity.

As such, since the vehicle speed is continuously proportionally controlled automatically, the screw conveyor 8 rotates at a speed later than the speed of the outer bowl 3 so that the solids in the outer bowl 3 are moved by the set concentration value. 3) It will be discharged to the outside.

At this time, the driving load is a force for rotating the outer bowl (3) and the sedimented solids to the screw conveyor (8) to the solids discharge bushing (10), the force for conveying the solids is connected to the screw conveyor (8) Is transmitted to the differential pulley 17 which rotates later than the rotation of the outer bowl 3.

Here, the differential pulley 17 receives the force to rotate at the rotational speed of the outer bowl (3) by the solid conveying load from the screw conveyor (8), if the differential pulley (17) the rotational speed of the outer bowl (3) If the rotational speed of the vehicle is zero, as shown in the above formula, since the rotation difference between the outer bowl 3 and the screw conveyor 8 is eliminated, the transport bowl 3 is not discharged from the inside to the outside.

Therefore, if the rotational speed of the vehicle speed motor 18 is set in advance, the vehicle speed controller 40 outputs the vehicle speed control value to the inverter 31 according to the load current corresponding to the concentration of the sludge injected and the solid discharge pressure. Accordingly, the vehicle speed motor 18 rotates.

That is, the inverter 31 receives the vehicle speed control value for driving the vehicle speed motor 18, rotates the vehicle speed motor 18 according to the vehicle speed control value, and outputs the load current to the vehicle speed controller 40 again. As a result, even if the concentration of the input sludge changes from time to time, the automatic control is performed to keep the concentration of the discharged solids constant by feedback control.

At this time, the vehicle speed controller 40 detects the load current value from the inverter 31 as described above, checks whether the braking current according to the vehicle speed and the solid discharge pressure is maintained and does not maintain the braking current according thereto. The result is transmitted to the inverter 31, whereby the inverter 31 is proportionally controlled according to the vehicle speed control value transmitted from the vehicle speed controller 40 so that the vehicle speed is achieved so that the rotation speed of the vehicle speed motor 18 is achieved. To control. This process is repeated until the inverter 31 maintains the vehicle speed braking current value corresponding to the vehicle speed.

On the other hand, when the load current value of Table 1 is larger than the Step 7, 8 value, that is, when the sludge concentration is instantaneously repeated at a concentration above the set range and the proper vehicle speed control value is not maintained by overload, the inverter 31 Separately, the operation stop and operation of the supply pump are repeated repeatedly, and the machine overload is checked and operated.If the concentration of the influent is higher than the set range and the input concentration is high and the device problem occurs, the supply pump is sequentially shut off. An abnormal signal is generated while the main motor 4 and the vehicle speed motor 18 are temporarily added or stopped.

The present invention is not limited to the above-described embodiments and can be implemented in various modifications within the scope of the technical idea of the present invention.

According to the present invention configured as described above, the vehicle speed control value is output through the load current of the inverter controlling the vehicle speed motor even if the concentration of the introduced sludge is changed, and the vehicle speed motor applies a braking current according to the vehicle speed control value so as to obtain the desired speed. It is possible to obtain the discharge solids of the shape, and to reduce the manufacturing cost of the centrifuge.

Accordingly, by controlling the rotational speed of the vehicle speed motor, clogging of solids in the outer cylinder can be prevented.

In addition, the separation liquid concentration changes the differential speed in the direction of preventing the carryover due to the fluctuation of the sludge supply concentration, thereby preventing the reduction of the solids recovery rate. It is effective.

Claims (2)

A screw conveyor is installed inside the outer bowl, and the main bowl and the speed motor which are controlled by each inverter and rotate the outer bowl and the screw conveyor are installed in the outer bowl and the screw conveyor. The outer bowl and the screw are installed through the inverter. In the centrifugal separator to separate the vehicle sludge into the discharged solids and the separation liquid to put the vehicle speed at the time of rotation of the conveyor, The load current value applied to the vehicle speed motor according to the concentration of the injected sludge and the solid discharge pressure electrically connected to the inverter and the vehicle speed motor is inputted from the inverter, and the load current value is set to the predetermined concentration of the sludge. And a vehicle speed controller for comparing and determining the braking current according to the solid discharge pressure and the braking current, and outputting the vehicle speed control value to the inverter so that the inverter proportionally controls the vehicle speed motor according to the vehicle speed control value. Automatic vehicle speed proportional control device of the centrifuge. The apparatus of claim 1, wherein the inverter drives the vehicle speed motor through an internal braking resistor to apply the surplus eddy current remaining and consumed as a regenerative electric power to the inverter of the main motor. .

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