Internal Circulation Ozone Tower for Wastewater Treatment

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Solution Overview

Problem

Current ozone treatment methods for industrial wastewater face challenges such as low ozone solubility in water, inefficient gas-water mixing, frequent clogging of packing materials, and fluctuating wastewater quality, which affect treatment efficiency and the suitability for high-flow industrial wastewater.

Innovation Solution

A contact reaction tower with internal ozone circulation, featuring a central and outer cylinder with lift pipes, influent pipes, and backflow holes, promoting turbulence and extended contact time through countercurrent and mixing contacts, and incorporating periodic washing of packing materials to prevent clogging and enhance mixing efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If ozonized air is injected into water using traditional aeration methods, then ozone can be transferred to water, but the solubility of ozone remains low (3-7mg/L) due to the low concentration of ozone in ozonized air (0.6%-1.2%)

Engineering Contradiction:
Improveozone solubility in waterVSAvoidtreatment efficiency
Core Design Contradiction:
Quantity of substanceVSProductivity

Solution Approach 1:

The patent employs a Venturi tube to create a pressure difference that draws ozonized air into the water flow, and uses a water jet to generate negative pressure that sucks ozone gas into the water. This pneumatic-hydraulic approach enables effective gas-liquid mixing without requiring complex mechanical devices, thereby increasing ozone solubility while maintaining treatment efficiency.

Inventive Principle:
Principle #29Pneumatics and hydraulics

Solution Approach 2:

The patent changes the pressure parameters by using the Venturi tube to create local negative pressure zones and the water jet to generate suction effects. By manipulating pressure differentials rather than relying on atmospheric pressure aeration, the system achieves higher ozone transfer efficiency and solubility in the treated water.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If packing materials are used in the reaction tower to increase contact area, then gas-water mixing is improved, but the packing materials frequently clog requiring maintenance

Engineering Contradiction:
Improvegas-water mixing efficiencyVSAvoidoperational continuity
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent removes the packing materials from the reaction tower design, extracting the source of clogging problems. Instead of using fixed packing structures that accumulate debris, the system relies on fluid dynamic mixing through Venturi tubes and water jets, eliminating the reliability issue while maintaining effective gas-water contact.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent uses pneumatic-hydraulic mixing devices (Venturi tubes and water jets) to achieve thorough gas-water mixing without mechanical or static structures that could clog. The high-velocity fluid streams create intense turbulence and contact between phases, replacing the function of packing materials while avoiding their drawbacks.

Inventive Principle:
Principle #29Pneumatics and hydraulics

3Productivity

If high flow rates are used to handle industrial wastewater, then treatment capacity increases, but gas-water contact time is reduced lowering mixing efficiency

Engineering Contradiction:
Improvetreatment capacityVSAvoidcontact time
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The patent creates intense turbulence and chaotic flow patterns through the Venturi tube and water jet interactions, which effectively mix gas and liquid phases in a very short residence time. The turbulent eddies and vortices generated increase the interfacial area and mass transfer coefficient, allowing efficient contact even at high flow rates where traditional laminar or transitional flow would be insufficient.

Inventive Principle:
Principle #18Mechanical vibration

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This design increases ozone solubility and mixing efficiency, improves treatment quality, and enhances the reaction tower's capacity to handle fluctuating loads, while also providing dissolved oxygen for subsequent aerobic bio-treatment processes.

Implementation Method 1

The internal circulation of the effluent caused by air lifting can enhance the disturbance of water current and bring about desirable turbulence of the effluent in the reaction tower

Methodology Applied
Scientific EffectAir lifting: Gas Lift

Implementation Method 2

the ozonized air diffuses in the form of microbubbles upward from micropore diffusers equipped at the bottom of the tower; the opposite directions of water and ozone ensure sufficient contact

Methodology Applied
Scientific EffectBubble formation and rise: Bubble

Implementation Method 3

Ozone is one of strong oxidants. It induces strong oxidative degradation of organic substances in wastewater and is able to turn complex organics into simple ones

Methodology Applied
Scientific EffectOxidation: Oxidation

Data Source

PatentEP2540677B1Contact reaction tower with internal circulation ozone used in industrial wastewater advanced treatment
Publication Date: 2020.11.25 NANJING UNIV
  • EP2540677B1 patent drawingFigure 1

AI summary

This invention discloses a contact reaction tower with internal circulating ozone for advanced treatment of industrial wastewater. The said contact reaction tower consists of a central cylinder and an outer cylinder. The central cylinder is internally equipped with lift pipes and influent pipes, and on the wall of the central cylinder exist backflow holes. The lift pipes, influent pipes and backflow holes form a circulation of water current between the central cylinder and the outer cylinder, which then realizes the internal circulation of the reaction tower; the whole reaction tower is sealed up and on the top of the tower stands a vent pipe. The internal circulation of the effluent realized in this invention can increase flow disturbance and form a desirable turbulent state in the reaction tower, which consequently extends the contact time between wastewater and ozonized air and guarantees sufficient contact and mixing of the gas and the water; the internal circulation of the effluent can also increase the reaction tower's capability against the impact load, ensures good effluent quality and convenient adjustment and control; the gas-water devices for washing the packing materials can ensure the high efficiency of gas-water mixing; the air lifting involved in reaction can also increase the concentration of oxygen in wastewater with its pre-aeration function, which is beneficial to the succeeding aerobic bio-treatment processes.