Cold Low-Pressure Separator Oil-Water Separation
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Solution Overview
Problem
Conventional low-pressure separators in petroleum refining and coal chemical industries suffer from poor liquid-gas separation efficiency, leading to gas loss and increased downstream load, poor oil-water separation, and high salt and hydrogen sulfide content in fractionated oil, resulting in equipment corrosion and ineffective desalination.
Innovation Solution
A method and device for enhanced oil-water separation and desalination in a cold low-pressure separator, utilizing a T-shaped liquid-gas separator, hydrophilic droplet agglomeration, and conjugated fiber modules to rapidly separate gas and water, with secondary washing and flow rectification, achieving efficient removal of salts and hydrogen sulfide.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If gravity settling is used for liquid-gas separation in a low-pressure separator, then the separation process is simple, but the separating effect is poor and tiny bubbles are carried into acidic water or fractionated oil
Solution Approach 1:
The separator is divided into multiple functional zones: a coalescence zone with coalescence plates for bubble aggregation, a settling zone for phase separation, and a desalination zone. This segmentation allows each zone to perform its specific function efficiently, improving overall separation效果 while maintaining reasonable structural complexity
Solution Approach 2:
Coalescence plates are introduced as intermediary elements between the mixing zone and settling zone. These plates provide a large surface area for tiny gas bubbles to coalesce into larger bubbles that can be more easily separated by gravity, acting as a mediator that enhances the separation process
2Reliability
If gravity settling is adopted for oil-water separation for 10 minutes or longer, then separation time is sufficient, but the separating effect is poor and large area is occupied
Solution Approach 1:
Coalescence plates with porous structures or corrugated surfaces are used to increase the interfacial area between oil and water phases. The large surface area of these plates promotes droplet coalescence and accelerates separation, achieving effective oil-water separation in a compact space without requiring long settling times
Solution Approach 2:
The separation process transitions from relying solely on vertical gravity settling to utilizing horizontal flow distribution across multiple plates. This dimensional change allows parallel processing of multiple fluid streams simultaneously, reducing the required footprint area while maintaining separation effectiveness
3Ease of manufacture
If conventional gravity settling is used, then equipment is simple, but salt and hydrogen sulfide content in fractionated oil increases causing corrosion
Solution Approach 1:
A dedicated desalination zone is extracted and added to the separator system. This zone uses washing water injection and coalescence mechanisms to specifically target and remove salts and hydrogen sulfide from the oil phase, separating these harmful components before the oil exits the separator, thereby protecting downstream equipment from corrosion
Solution Approach 2:
The desalination function is performed preliminarily within the separator itself before oil enters downstream processing equipment. By removing salts and hydrogen sulfide in advance through washing and coalescence processes, the oil is pre-protected from causing corrosion in subsequent steam stripping and distillation units
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 approach significantly improves separation efficiency, reduces gas loss, lowers hydrogen content in oil, and decreases salt and hydrogen sulfide in the oil product, enhancing downstream process efficiency and reducing corrosion, while occupying less space and reducing processing time.
Implementation Method 1
rapidly separate gas from the oil-water mixture via flash evaporation
Implementation Method 2
the hydrophilic droplet agglomeration module is adopted to rapidly agglomerate the water droplets scattering in oil
Implementation Method 3
the CPI fast separation module performs rapid oil-water separation, the separated water is automatically discharged from bottom
Implementation Method 4
deep water removal by a conjugated fiber water removal module containing hydrophilic fibers and oleophilic fibers
Data Source
Figure 1
AI summary
This invention involves a method and a device for enhanced oil-water separation and desalination in a low-pressure separator. The water-containing oil is mixed with desalted water in a countercurrent way at the entrance, wherein the desalted water accounts for 0-1% of the water-containing oil by volume. The resultant oil-water mixture then enters a T-shaped liquid-gas separator (3) for degassing treatment to quickly separate gas from the mixture. In a low-pressure separator, the oil-water mixture flows, from left to right, to a flow conditioner (4) to uniformly distribute the mixture in the transverse section, and then flows to a hydrophilic droplet agglomeration module (5) and a CPI fast separation module (6) to separate water from oil, wherein part of the separated water is discharged and the oil with a trace of water (0-0.01%) passes over a partition (18) to a deep separation segment. The oil is subjected to deep water removal by a conjugated fiber water removal module and then discharged, and the water captured by the conjugated fiber water removal module is subject to a conjugated fiber oil removal module for deep oil removal and then discharged.