A sewage aeration system

Abstract

The present invention discloses a sewage aeration system, which aims to solve the problems of high energy consumption, high failure rate and noise pollution in the prior art. The system automatically adjusts the aeration pressure and frequency according to the water depth of the oxygen consumption tank by using a frequency converter to control the motor, so as to keep the air flow and pressure constant. The system also includes interlock control to prevent two Roots blowers from starting and running at the same time, as well as electrical control logic to realize the entire control process from emergency stop switch to control power supply connection, and then to start the blower and adjust the frequency of the frequency converter. The improved system reduces energy consumption and failure rate, reduces mechanical wear, reduces noise pollution, and improves the convenience of operation and the energy efficiency of the system, meeting the requirements of energy saving and consumption reduction. The technical points and beneficial effects created by the present invention provide an efficient, stable and environmentally friendly solution for sewage aeration systems.

Description

Technical Field

[0001] The invention relates to sewage treatment equipment, in particular to a sewage aeration system. Background Art

[0002] In the existing sewage aeration system, three-blade Roots blowers are mainly used as the aeration main unit, and the electronic control system adopts star-delta step-down starting control and works in the power frequency state. This configuration has multiple defects: loud noise, high heat, heavy load, and high power consumption during operation; the equipment has large operating current, high energy consumption, and easy heat generation, which leads to frequent damage to electrical appliances and motors, high electrical failure rate, and frequent maintenance. In addition, when a large motor is started elsewhere, the input voltage is reduced, and the contactor is prone to low voltage loss and tripping. These problems have led to deficiencies in the existing technology in terms of efficiency, energy consumption, stability, and environmental impact. Summary of the invention

[0003] The object of the present invention is to provide a sewage aeration system.

[0004] To achieve the above object, the present invention is implemented according to the following technical solutions:

[0005] The present invention comprises: at least one oxygen consumption tank; at least two Roots blowers, which provide oxygen to the oxygen consumption tank; at least one frequency converter for controlling the operation of the Roots blowers; the frequency converter adjusts the output frequency according to the water depth of the oxygen consumption tank to keep the air flow rate and the aeration pressure constant; an interlocking control is arranged between the Roots blowers and the frequency converter to prevent the two Roots blowers from starting and running at the same time.

[0006] A circuit breaker is connected to the power input end of the frequency converter, and at least two AC contactors are provided at the output end of the frequency converter. The control ends of the two AC contactors are respectively connected to the control ends of two Roots blowers to control the start and stop of the Roots blowers. The frequency converter and the contactors are each provided with a group of buttons for controlling the start and stop.

[0007] The frequency converter is provided with a frequency meter, which is connected to the frequency signal output end of the frequency converter and is used to display the current output frequency of the frequency converter. A thermostat is also provided in the electric control cabinet, and the temperature monitoring end of the thermostat is placed near the frequency converter to monitor the temperature near the frequency converter. An exhaust fan is also provided on the electric control cabinet, and the control end of the exhaust fan is connected to the control signal output end of the thermostat. The exhaust fan is started when the temperature is set to 37°C, and is stopped when the temperature is 32°C.

[0008] Preferably, the frequency adjustment range of the frequency converter is 39 Hz to 45 Hz. The output frequency of the frequency converter is 39.5 Hz when the water depth of the aerobic pool is 8 meters, so as to maintain the aeration pressure at 52 KPa; and 41.5 Hz when the water depth of the aerobic pool is 9 meters, so as to maintain the aeration pressure at 56 KPa.

[0009] The beneficial effects of the present invention are:

[0010] The present invention is a sewage aeration system. Compared with the prior art, the present invention has the following technical effects:

[0011] Reduce energy consumption and failure rate: By using a frequency converter to control the motor and keep the pressure and flow constant, energy consumption and failure rate are significantly reduced.

[0012] Reduce mechanical wear: Reduce the operating frequency, reduce mechanical wear, and extend the service life of bearings and gears.

[0013] Reduce electrical failure rate: Motor power consumption, current, and heat generation are reduced, which reduces electrical damage and electrical failure rate.

[0014] Reduce noise pollution: The improved system noise is significantly reduced, reducing noise pollution to the environment.

[0015] Improve operational convenience: easy operation, smooth switching, precise protection system, and obvious and convenient numerical monitoring.

[0016] Improve energy efficiency: After adopting the frequency conversion system, the motor efficiency is increased to more than 90%, the power consumption is reduced, and the requirements of energy saving and consumption reduction are met. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the structure of the present invention;

[0018] Figure 2 It is a control circuit structure principle diagram of the present invention. DETAILED DESCRIPTION

[0019] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments. The illustrative embodiments and descriptions of the present invention are used to explain the present invention but are not intended to limit the present invention.

[0020] like Figure 1 and Figure 2As shown: The present invention includes: at least one oxygen consumption tank, 1 and 2 in the figure are both oxygen consumption tanks; at least two Roots blowers, M1-M4 in the figure, the Roots blowers provide oxygen to the oxygen consumption tank; at least one frequency converter for controlling the operation of the Roots blowers; the frequency converter adjusts the output frequency according to the water depth of the oxygen consumption tank to keep the air flow and aeration pressure constant; an interlocking control is provided between the Roots blower and the frequency converter to prevent the two Roots blowers from starting and running at the same time.

[0021] A circuit breaker is connected to the power input end of the frequency converter, and at least two AC contactors are provided at the output end of the frequency converter. The control ends of the two AC contactors are respectively connected to the control ends of two Roots blowers to control the start and stop of the Roots blowers. The frequency converter and the contactors are each provided with a group of buttons for controlling the start and stop.

[0022] The frequency converter is provided with a frequency meter, which is connected to the frequency signal output end of the frequency converter and is used to display the current output frequency of the frequency converter. A thermostat is also provided in the electric control cabinet, and the temperature monitoring end of the thermostat is placed near the frequency converter to monitor the temperature near the frequency converter. An exhaust fan is also provided on the electric control cabinet, and the control end of the exhaust fan is connected to the control signal output end of the thermostat. The exhaust fan is started when the temperature is set to 37°C, and is stopped when the temperature is 32°C.

[0023] Preferably, the frequency adjustment range of the frequency converter is 39 Hz to 45 Hz. The output frequency of the frequency converter is 39.5 Hz when the water depth of the aerobic pool is 8 meters, so as to maintain the aeration pressure at 52 KPa; and 41.5 Hz when the water depth of the aerobic pool is 9 meters, so as to maintain the aeration pressure at 56 KPa.

[0024] Control logic: turn on the emergency stop switch SE → control power supply is turned on → power indicator HL1 is on → start SB1 → contactor KM1 is closed → inverter G1 is started → 1# fan is running (if the output frequency of inverter G1 is slightly low at this time, you can click the frequency increase button SB5 to increase the output frequency of inverter G1; if the output frequency of inverter G1 is slightly high at this time, click the frequency reduction button SB6 to reduce the output frequency of inverter G1; or start SB3 → contactor KM2 is closed → inverter G1 is started → 2# fan is running (if the output frequency of inverter G1 is slightly low at this time, you can click the frequency increase button SB5 to increase the output frequency of inverter G1; if the output frequency of inverter G1 is slightly high at this time, click the frequency reduction button SB6 to reduce the output frequency of inverter G1; start SB7 → contactor KM3 is closed → inverter G 2 Start → 3# fan runs (if the output frequency of inverter G2 is slightly low at this time, you can click the frequency increase button SB11 to increase the output frequency of inverter G2; if the output frequency of inverter G2 is slightly high at this time, click the frequency reduction button SB12 to reduce the output frequency of inverter; or start SB9 → contactor KM4 is energized → inverter G2 starts → 4# fan runs (if the output frequency of inverter G2 is slightly low at this time, you can click the frequency increase button SB11 to increase the output frequency of inverter G2; if the output frequency of inverter G2 is slightly high at this time, click the frequency reduction button SB12 to reduce the output frequency of inverter; press button SB2 to stop 1# fan, press button SB4 to stop 2# fan, press button SB8 to stop 3# fan, press button SB10 to stop 4# fan.

[0025] ① The inverter output controls the motor. When the water depth of the oxygen consumption pool is 8 meters, the aeration pressure (52KPa) and the inverter output frequency (39.5Hz) maintain the air flow; when the water depth of the oxygen consumption pool is 9 meters, the aeration pressure (56KPa) and the inverter output frequency are high (41.5Hz) to maintain the air flow;

[0026] ② Two Roots blowers share one frequency converter, and two oxygen consumption pools use four Roots blowers, one for backup and one for use in each pool; when one Roots blower fails, it can be switched to another Roots blower. The electrical appliances of the two Roots blowers are interlocked and cannot be started and operated at the same time.

[0027] ③The power supply of circuit breaker QF1 is connected to the frequency converter G1, and the output end of frequency converter G1 is connected to two 63A AC contactors KM1 and KM2 (model: CJX1-63). The AC contactor KM1 outputs to the Roots blower motor M1, and the AC contactor KM2 outputs to the Roots blower motor M2. KM1 and KM2 are interlocked and controlled. When the start button SB1 is pressed, the contactor KM1 is energized and the contactor KM2 is not energized. When the start button SB3 is pressed, the contactor KM2 is energized and the contactor KM1 is not energized. SB2 is the 1# stop button, SB4 is the 2# stop button, SB5 is the frequency increase button of frequency converter G1, and SB6 is the frequency decrease button of frequency converter G1.

[0028] ④The power supply of circuit breaker QF2 is connected to the frequency converter G2, and the output end of frequency converter G2 is connected to two 63A AC contactors KM3 and KM4 (model: CJX1-63). The AC contactor KM3 outputs to the Roots blower motor M3, and the AC contactor KM4 outputs to the Roots blower motor M4. KM3 and KM4 are interlocked and controlled. When the start button SB7 is pressed, the contactor KM3 is energized and the contactor KM4 is not energized. When the start button SB9 is pressed, the contactor KM4 is energized and the contactor KM3 is not energized. SB8 is the 3# stop button, SB10 is the 4# stop button, SB11 is the frequency increase button of frequency converter G2, and SB12 is the frequency decrease button of frequency converter G2.

[0029] ⑤ Inverter starting mode: When starting contactor KM1, the auxiliary contact of contactor KM1 connects to the starting terminal of inverter G1, DI1 and COM are connected, inverter G1 starts after a delay of 5S, outputs power to contactor KM1, and then to Roots blower motor M1 for operation; when starting contactor KM2, the auxiliary contact of contactor KM2 connects to the starting terminal of inverter G1, DI1 and COM are connected, inverter G1 starts after a delay of 5S, outputs power to contactor KM2, and then to Roots blower motor M2 runs; when contactor KM3 is started, the auxiliary contact of contactor KM3 is connected to the starting end of inverter G2, DI1 is connected to COM, inverter G2 starts after a delay of 5S, outputs power to contactor KM3, and then to Roots blower motor M3 runs; when contactor KM4 is started, the auxiliary contact of contactor KM4 is connected to the starting end of inverter G2, DI1 is connected to COM, inverter G2 starts after a delay of 5S, outputs power to contactor KM4, and then to Roots blower motor M4 runs.

[0030] ⑥ Frequency adjustment of inverter: In order to ensure normal production operation, the frequency of the inverter is limited. The lower limit frequency is (39Hz) and the upper limit frequency is (45Hz). This can keep the fan running in the best linear state, and the energy consumption, current and heat will be reduced accordingly, which can not only meet the requirements of energy saving and consumption reduction, but also ensure production. If it is really necessary to adjust the operating frequency, such as clicking the frequency increase button SB5 of the frequency converter G1, KA1 connects the frequency increase input terminal DI2 of the frequency converter G1 and connects it with COM, that is, the operating frequency is increased, and the frequency meter Hz can display the increased value; clicking the frequency decrease button SB6, KA2 connects the frequency decrease input terminal DI3 of the frequency converter G1 and connects it with COM, that is, the operating frequency is decreased, and the frequency meter Hz can display the decreased value; clicking the frequency increase button SB11 of the frequency converter G2, KA3 connects the frequency increase input terminal DI2 of the frequency converter G2 and connects it with COM, that is, the operating frequency is increased, and the frequency meter Hz can display the increased value; clicking the frequency decrease button SB12, KA4 connects the frequency decrease input terminal DI2 of the frequency converter G2 and connects it with COM, that is, the operating frequency is decreased, and the frequency meter Hz can display the decreased value; the adjustment range of the frequency converters G1 and G2 is limited to (39Hz~45Hz).

[0031] The technical solution of the present invention is not limited to the above-mentioned specific embodiments. All technical variations made according to the technical solution of the present invention fall within the protection scope of the present invention.

Claims

1. A sewage aeration system, characterized in that: include: at least one aerobic pool; At least two Roots blowers, which provide oxygen to the oxygen consumption pool; at least one frequency converter for controlling the operation of the Roots blowers; the frequency converter adjusts the output frequency according to the water depth of the oxygen consumption pool to keep the air flow and aeration pressure constant; an interlock control is provided between the Roots blower and the frequency converter to prevent the two Roots blowers from starting and running at the same time.

2. The sewage aeration system according to claim 1, characterized in that: A circuit breaker is connected to the power input end of the frequency converter, and at least two AC contactors are provided at the output end of the frequency converter. The control ends of the two AC contactors are respectively connected to the control ends of two Roots blowers to control the start and stop of the Roots blowers. The frequency converter and the contactors are each provided with a group of buttons for controlling the start and stop.

3. The sewage aeration system according to claim 2, characterized in that: The frequency converter is provided with a frequency meter, which is connected to the frequency signal output end of the frequency converter and is used to display the current output frequency of the frequency converter. A thermostat is also provided in the electric control cabinet, and the temperature monitoring end of the thermostat is placed near the frequency converter to monitor the temperature near the frequency converter. An exhaust fan is also provided on the electric control cabinet, and the control end of the exhaust fan is connected to the control signal output end of the thermostat. The exhaust fan is started when the temperature is set to 37°C, and is stopped when the temperature is 32°C.

4. The sewage aeration system according to claim 3, characterized in that: The frequency adjustment range of the frequency converter is 39 Hz to 45 Hz.

5. The sewage aeration system according to claim 4, characterized in that: The output frequency of the frequency converter is 39.5 Hz when the water depth of the aerobic pool is 8 meters, so as to maintain the aeration pressure at 52 KPa; and is 41.5 Hz when the water depth of the aerobic pool is 9 meters, so as to maintain the aeration pressure at 56 KPa.

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