Pressure Filter Machine for PTA Acetic Acid Recovery
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Solution Overview
Problem
The existing methods for processing acetic acid solvent in crude terephthalic acid in PTA industrial apparatuses are inefficient, requiring long process flows, high investment costs, and significant energy consumption, with complications such as equipment failure, safety hazards, and inefficient washing processes due to the use of multiple equipment and high viscosity of crude terephthalic acid.
Innovation Solution
A method involving a pressure filter machine with a multi-stage counter-current washing process using bias-current and conduction techniques to separate and reuse residual liquids, and nitrogen gas to regulate pressure balance, reducing washing liquid consumption and preventing seal damage between chambers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If multiple equipments (vacuum filter, steam rotary dryer, washing tower) are used for acetic acid removal, then separation efficiency is improved, but device complexity and investment cost increase
Solution Approach 1:
The patent combines filtration and drying functions into a single integrated pressure filter machine. The machine includes a filtering area for separating acetic acid from crude terephthalic acid slurry and a drying area for evaporating acetic acid from the filter cake, eliminating the need for separate vacuum filter and steam rotary dryer equipments.
Solution Approach 2:
The pressure filter machine performs multiple functions within a single device: filtration to separate solid particles from liquid, drying to remove acetic acid through evaporation, and washing to clean the filter cake. This multi-functional design reduces the number of accessory equipments and simplifies the process flow.
2Manufacturing precision
If multiple equipments are used for acetic acid removal, then separation efficiency is improved, but floor space occupation increases
Solution Approach 1:
The patent combines filtration and drying functions into a single integrated pressure filter machine. The machine includes a filtering area for separating acetic acid from crude terephthalic acid slurry and a drying area for evaporating acetic acid from the filter cake, eliminating the need for separate vacuum filter and steam rotary dryer equipments.
3Manufacturing precision
If conventional filtration and drying process is used, then acetic acid removal is achieved, but energy consumption increases
Solution Approach 1:
The pressure filter machine operates continuously with the pressure filter drum rotating through different areas (filtering area, drying area, washing area, unloading area). The filtering and drying processes occur simultaneously in different sectors of the same drum, eliminating idle time between operations and reducing overall energy consumption compared to sequential batch processing.
4Ease of operation
If washing liquid flows from one washing area to the next via filtrate pipe, then washing process is simplified, but washing efficiency decreases due to increased concentration
Solution Approach 1:
The patent extracts and removes the residual liquid from the filtrate pipe before it can flow into the next washing area. By taking out this concentrated residual liquid, the system prevents contamination of the fresh washing liquid in subsequent areas, maintaining washing efficiency while keeping the process simple.
Solution Approach 2:
The patent introduces an intermediary mechanism (residual liquid removal system) between the filtrate pipe and the washing areas. This intermediary component intercepts and removes the residual liquid, preventing it from acting as a harmful mediator that would concentrate and reduce washing efficiency in the next washing area.
5Device complexity
If pressure filter machine operates without pressure balance regulation, then structure is simplified, but seal damage and liquid mixing occur between chambers
Solution Approach 1:
The patent implements a pressure balance regulation system that continuously monitors and adjusts the pressure differential across the filter drum chambers. By maintaining equal pressure on both sides of the filter drum, the system provides feedback control that prevents seal damage and liquid mixing between chambers, ensuring reliable operation.
Solution Approach 2:
The pressure balance regulation system maintains equal pressure potential across different chambers of the pressure filter machine. By keeping the pressure differential at zero or near-zero, the system creates equipotential conditions that eliminate the driving force for liquid leakage and seal damage, while preventing mixing between different washing stages.
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 method enhances washing efficiency, reduces water and energy consumption, and maintains pressure balance, preventing liquid mixing and equipment damage, thus improving the overall processing efficiency and cost-effectiveness.
Implementation Method 1
conveying pressurized CTA slurry into a filtering area of a pressure filter to separate solid particles and acetic acid in the CTA slurry
Implementation Method 2
conveying the resultant crude terephthalic acid filter cake to a steam rotary dryer to heat and dry it with steam indirectly, removing acetic acid from crude terephthalic acid by drying
Implementation Method 3
The steam rotary dryer evaporates acetic acid from crude terephthalic acid with latent heat of steam
Implementation Method 4
feeding nitrogen gas into a pressure filter, a mother liquor tank and respective washing liquid tanks to regulate a pressure balance of a system
Data Source
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AI summary
The present invention relates to a method for processing acetic acid solvent in an oxidising unit of a PTA industrial apparatus; said method uses a pressure filter machine to filter crude terephthalic acid slurry, and then, using a multi-stage counter-current method, uses washing water to wash the acetic acid solvent, and, by means of setting up a bias-current and drainage, prevents residual liquid in the filtrate pipe from entering the next area following the rotation of the pressure filter machine, improving washing efficiency and reducing the amount of washing water; the present invention integrates the processes of filtering and washing crude terephthalic acid into a single pressure filter machine, such that the process is shorter, the occupied floor space is reduced, and energy consumption is lower. A method feeding nitrogen gas into the mother liquor tank and washing liquid tank is used to regulate the pressure balance of the system.