Process for the continual inline filtration of a process stream

Patent metadata

Field	Value
Publication number	US-10751649-B2
Application number	US-201615099801-A
Country	US
Kind code	B2
Filing date	Apr 15, 2016
Priority date	Apr 20, 2015
Publication date	Aug 25, 2020
Grant date	Aug 25, 2020

Abstract

The present invention provides a new type of filtration system. Traditional designs required that personnel open the system to clean/change strainers while a process was in operation. This invention provides a straining system that allows process stream to be filtered in a manner completely internal to the process. The system includes dual strainers with a nitrogen purging system and solvent flush system. A creatively designed “catch” area is installed internal to the process to collect all solids that are flushed from the strainer system. The system remains completely closed for the duration of each production campaign, thus eliminating the safety hazard and labor requirement associated with opening a process system.

First claim

What is claimed is:

1. A continuous inline filtration process having a first strainer pot and a second strainer pot, each of the first and second strainer pots having an outlet, an inlet, a strainer basket and a spray nozzle, and each strainer basket having an outside surface and an inside surface, comprising:
i) feeding a process stream containing solids and liquids into the inlet of the first strainer pot;
ii) straining the process stream through the strainer basket of the first strainer pot to create a first strained process stream;
iii) collecting solids from the process stream on the outside surface of the strainer basket of the first strainer pot;
iv) removing the first strained process stream from the outlet of the first strainer pot;
v) diverting the process stream from the inlet of the first strainer pot to the inlet of second strainer pot;
vi) straining the diverted process stream through the strainer basket of the second strainer pot to create a second strained process stream;
vii) collecting solids from the diverted process stream on the outside surface of the strainer basket of the second strainer pot;
viii) removing the second strained process stream from the outlet of the second strainer pot;
ix) after step v), spraying a flush solution from the spray nozzle of the first strainer pot; and
x) flushing solids from the outside surface of the first strainer pot to a collection tank vessel located below the first strainer pot,
wherein each step is accomplished in equipment that is closed during operation.

2. The process of claim 1 , wherein process steps vii) and x) are done simultaneously.

3. The process of claim 1 , wherein the flush solution comprises monochlorobenzene.

4. The process of claim 1 , wherein the collection tank vessel comprises a metal plate having one or more openings sized and shaped to permit liquid to pass therethrough.

5. The process of claim 1 , further comprising:
xi) diverting the process stream from the inlet of the second strainer pot to the inlet of the first strainer pot;
xii) after step xi), spraying a flush solution from the spray nozzle of the second strainer pot; and
xiii) flushing solids from the outside surface of the second strainer pot to a collection tank vessel located below the first strainer pot.

6. The process of claim 1 , wherein the process further comprises a nitrogen purge.

7. The process of claim 1 , wherein the process further comprises dephosgenation.

Assignees

• Covestro Llc
• Covestro Polymers (China) Co Ltd
• Covestro Polymers (China) Co Ltd

Inventors

• Rogers Hicks Amber
• Hassell William A
• Kelleher Kevin M
• Swart Kent
• Lau Wingwah
• Tang Bin
• Steindel Norbert

Classifications

• B01D35/02 Primary

  Filters adapted for location in special places, e.g. pipe-lines, pumps, stop-cocks, (B01D35/05 takes precedence; {water pipe system filters E03B3/18, E03B7/07; dirt catchers in sewers E03F; filters or strainers for pipe-lines in general B08B, E03F; object or dirt catching devices in sinks or the like E03C1/26; suction strainers or filters for pumps F04B53/005, F04D29/70}) · CPC title

• B01D29/68

  with backwash arms, shoes or nozzles · CPC title

• B01D29/33

  arranged for inward flow filtration · CPC title

• B01D29/52

  in parallel connection · CPC title

• B01D29/66

  by flushing, e.g. counter-current air-bumps · CPC title