Aerobic tank aeration method in industrial wastewater treatment

Abstract

The invention relates to the field of industrial wastewater treatment, in particular to an aeration method of an aerobic tank in industrial wastewater treatment. The air filter is additionally arranged in front of an air inlet pipeline of the frequency conversion fan, impurities such as oil drops and dust in the air filter are removed, the filtering and purifying effects are achieved, the gas pipeline mixer is additionally arranged, the oxygen pipeline is additionally arranged on the gas pipeline mixer, and the purpose of achieving the oxygen content of the aeration system through valve adjustment is achieved; and a dissolved oxygen tester is arranged at an inlet and an outlet of the aerobic tank and is connected with a control system. The air filter is additionally arranged to remove flammable and explosive media, the oxygen content is monitored on line and automatically controlled, safety and reliability are achieved, stable operation of the system is guaranteed, the oxygen pipeline is additionally arranged on the newly-arranged gas pipeline mixer, air and oxygen are fully mixed, the oxygen utilization efficiency is improved, and the oxygen utilization rate is increased while the oxygen requirement of biochemical reaction is met. The energy consumption of the fan is reduced, and the operation cost is saved.

Description

Technical Field

[0001] The present invention relates to the field of sewage treatment, in particular to an aerobic pool oxygenation and aeration system for a biochemical system, and is particularly suitable for an aerobic pool aeration method used in the treatment of industrial wastewater such as coking ammonia evaporation wastewater. Background Art

[0002] In the biochemical wastewater treatment process, aerobic tank aeration systems play a key role, providing microorganisms with essential oxygen to promote the degradation of organic matter. Biochemical system aerobic tanks utilize both air aeration and pure oxygen aeration. Traditional air-blower aeration systems typically use a blower to pressurize air, then pipe it to an aerator (such as a microporous aeration head or perforated tube), where it is released into the water as bubbles. This system is complex and requires regular cleaning of the aeration head to prevent clogging. During high summer temperatures, the biochemical system's oxygen demand increases, requiring the blower to consume significant amounts of electricity to achieve a high dissolved oxygen level. This approach suffers from low oxygen utilization efficiency and high energy consumption. When treating difficult-to-degrade industrial wastewater, such as coking ammonia wastewater, traditional aeration systems often struggle to meet the oxygen demand for biochemical reactions, resulting in poor treatment results and increased operating costs. Pure oxygen aeration uses pure oxygen (rather than air) as the oxygen source, increasing the oxygen partial pressure within a closed reactor to accelerate microbial metabolism. However, the high cost of oxygen necessitates additional safety and explosion prevention measures. The treatment efficiency is high, but the equipment is complex and the process conditions are harsh. Excessive oxygen can cause explosion risks. Properly increasing the oxygen concentration can effectively reduce the energy consumption of the air aeration process and greatly reduce the safety issues caused by excessive oxygen content. Summary of the Invention

[0003] The purpose of the present invention is to provide an oxygen-enhancing aeration system for an aerobic pool in a biochemical system. By adding an oxygen pipeline to the air inlet of a traditional air blower aeration system, the opening of the oxygen flow valve is controlled, and the oxygen content of the aeration system is adjusted. Under the premise of not exceeding the oxygen content specified by the national standard, the oxygen content in the aeration system is increased, thereby achieving energy saving effects and ensuring the safety and stability of the system operation.

[0004] A new air filter removes impurities such as oil droplets and dust, providing a filtering and purification effect, preventing these substances from entering subsequent systems and impacting operations or posing safety hazards. Air then enters a new pipeline mixer, where oxygen is also introduced. The mixed gas is then pressurized and transported by a variable frequency fan to the aeration system of the aerobic tank, providing oxygen for the microorganisms within the aerobic tank. This process allows the oxygen content in the aeration system to be appropriately increased without exceeding national standards, achieving energy savings and other benefits.

[0005] The specific embodiments of the present invention are as follows: (1) Air pretreatment: A new air filter with a filtration accuracy of 0.1-100 microns is added to filter out flammable and explosive media such as oil droplets and dust in the air, ensuring that the air entering the aeration system is clean and reducing safety risks; (2) Oxygen mixing: The pre-treated air is introduced into the pipeline in front of the gas blower, and a gas pipeline mixer is added in the pipeline to mix oxygen into the blower through the mixer so that the air and oxygen are fully mixed; (3) Oxygen content control: Use a variable frequency fan and install an oxygen analyzer in the fan outlet pipe. The oxygen analyzer adopts an online operation mode to control the oxygen content within the range of 20.5% - 23.5% as needed. Among them, 20.5% is the oxygen content in the original air, and 23.5% is the maximum oxygen content limit required by the national standard; (4) Dissolved oxygen regulation: A dissolved oxygen meter is installed at the inlet and outlet of the aerobic pool. According to the requirements of the biochemical system, the dissolved oxygen in the aerobic pool is adjusted to the appropriate content by adjusting the opening of the oxygen flow valve and the frequency of the variable frequency fan; (5) Safety control: The air blower uses a variable frequency pump. After the blower is turned on, the oxygen valve is gradually opened. When the oxygen content reaches 23%, the motor frequency is increased to make the dissolved oxygen reach the range required by biochemistry. When the oxygen content reaches 23.5% or above, the pipeline mixer oxygen valve is automatically closed to prevent the risk of combustion or explosion due to excessive oxygen.

[0006] Compared with the existing technology, the present invention has the following advantages: 1. Significant energy-saving effect: By appropriately increasing the oxygen content in the aeration system, the oxygen utilization efficiency is improved. While meeting the oxygen demand of biochemical reactions, the fan energy consumption is reduced, saving operating costs.

[0007] 2. Safe and reliable: Multiple safety control measures are set up, including air filtration to remove flammable and explosive media, online monitoring of oxygen content and automatic control valves, which effectively prevent safety accidents such as combustion or explosion caused by excessive oxygen concentration and ensure stable operation of the system.

[0008] 3. Precise control: Oxygen analyzers and dissolved oxygen meters can accurately monitor oxygen and dissolved oxygen content in real time, and precise adjustment can be achieved through variable frequency fans and oxygen flow valves to meet the oxygen requirements of different biochemical treatment processes. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The present invention will be further described below with reference to the accompanying drawings and examples.

[0010] Figure 1 It is a process flow diagram of the present invention. DETAILED DESCRIPTION

[0011] The specific implementation methods are as follows: Install a new air filter, ensuring that its filtration accuracy is between 0.1 and 100 microns, and connect it to the air intake line to pre-treat the air entering the system to remove impurities such as oil droplets and dust.

[0012] Add a gas pipeline mixer at a suitable position in the pipeline in front of the gas blower, and correctly connect the oxygen pipeline to the pipeline mixer to ensure that oxygen can be smoothly mixed into the air flow.

[0013] Install a variable frequency fan and an oxygen analyzer in the fan outlet pipe. Connect the oxygen analyzer to the control system and set the oxygen content control range to 20.5% - 23.5%.

[0014] Install a dissolved oxygen meter at the inlet and outlet of the aerobic pool, connect it to the control system, and set the dissolved oxygen target value based on the dissolved oxygen requirements of the biochemical system.

[0015] Turn on the air fan. After the fan runs stably, gradually open the oxygen valve to introduce oxygen into the pipeline mixer. Use the oxygen analyzer to monitor the oxygen content at the fan outlet in real time. When the oxygen content is close to 23%, according to the feedback data from the aerobic tank dissolved oxygen meter, appropriately increase the frequency of the variable frequency fan motor and increase the aeration volume to make the dissolved oxygen in the aerobic tank reach the appropriate range.

[0016] When the oxygen analyzer detects that the oxygen content reaches 23.5% or above, the control system automatically closes the pipeline mixer oxygen valve and stops the oxygen supply to prevent the risk of combustion or explosion due to excessive oxygen. After the oxygen content drops to an appropriate range, the valve will be reopened to supply oxygen as needed.

[0017] After the air is pre-treated by the air filter, flammable and explosive media such as oil droplets and dust are removed, making it relatively clean air. At this time, this pre-treated air will be introduced into the pipe in front of the gas blower.

[0018] A gas mixer has been specially installed on this pipeline. A gas mixer is a device that allows different gases to be thoroughly mixed. It features specialized internal structural designs, such as flow disturbance elements and a unique flow channel shape. Oxygen is connected to the gas mixer via a dedicated oxygen pipeline. When oxygen flows into the gas mixer, due to the mixer's internal structure, it experiences significant agitation and mixing with the pre-treated air flowing in simultaneously.

[0019] Within the mixer, air and oxygen utilize turbulent elements to continuously change direction and speed, increasing the chance of collision between the two gas molecules. Furthermore, specially designed flow channels allow oxygen and air to intertwine at appropriate flow rates and directions, achieving uniform mixing. The mixed gas then enters the gas blower, where it is further transported to the subsequent aeration system, providing aeration gas with a regulated oxygen content to the aerobic tank to meet the biochemical system's oxygen needs.

Claims

1. An aerobic tank aeration method for industrial wastewater treatment, characterized in that The specific steps are as follows: (1) Air pretreatment: A new air filter with a filtration accuracy of 0.1-100 microns is added to filter out flammable and explosive media such as oil droplets and dust in the air, ensuring that the air entering the aeration system is clean and reducing safety risks; (2) Oxygen mixing: The pre-treated air is introduced into the pipeline in front of the gas blower, and a gas pipeline mixer is added in the pipeline to mix oxygen into the blower through the mixer so that the air and oxygen are fully mixed; (3) Oxygen content control: Use a variable frequency fan and set an oxygen analyzer in the fan outlet pipe. The oxygen analyzer adopts online operation mode to control the oxygen content in the range of 20.5% - 23.5% as needed, among which 20.5% is the oxygen content in the original air and 23.5% is the maximum oxygen content limit required by the national standard; (4) Dissolved oxygen regulation: A dissolved oxygen meter is installed at the inlet and outlet of the aerobic pool. According to the requirements of the biochemical system, the dissolved oxygen in the aerobic pool is adjusted to the appropriate content by adjusting the opening of the oxygen flow valve and the frequency of the variable frequency fan; (5) Safety control: The air blower uses a variable frequency pump. After the blower is turned on, the oxygen valve is gradually opened. When the oxygen content reaches 23%, the motor frequency is increased to make the dissolved oxygen reach the range required by biochemistry. When the oxygen content reaches 23.5% or above, the pipeline mixer oxygen valve is automatically closed to prevent the risk of combustion or explosion due to excessive oxygen.

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