Submicron particle removal from gas streams

Patent metadata

Field	Value
Publication number	US-10730002-B2
Application number	US-201715495667-A
Country	US
Kind code	B2
Filing date	Apr 24, 2017
Priority date	May 9, 2016
Publication date	Aug 4, 2020
Grant date	Aug 4, 2020

Abstract

Disclosed are methods and systems for removing submicron particles from a gas stream, in particular from urea prilling off-gas, wherein a Venturi ejector is used. A method comprises contacting a gas stream containing submicron particles in a Venturi ejector with an injected high velocity scrubbing liquid to provide a pumping action, wherein the scrubbing liquid has an initial velocity of at least 25 m/s and wherein the ratio of scrubbing liquid and gas flow is between 0.0005 and 0.0015 (m 3 /h)/(m 3 /h).

First claim

The invention claimed is:

1. A urea prilling tower having a gas stream treatment system at the top of the urea prilling tower, wherein the gas stream treatment system comprises two Venturi stages in series, wherein each of said Venturi stages comprises a Venturi ejector.

2. The urea prilling tower of claim 1 , wherein each of said Venturi ejectors is horizontally placed and comprises a converging part, a throat, and a diverging tube part, and a nozzle for spraying a liquid into said throat, wherein said Venturi stages are placed above each other, and wherein each Venturi stage comprises a scrubbing liquid recirculation loop comprising a pump for pressurizing and recirculating scrubbing liquid to said nozzle, wherein the Venturi stages have separate recirculation loops.

3. The urea prilling tower of claim 2 , wherein the gas stream treatment system further comprises a sprayer between a first and a downstream second Venturi stage, for spraying an aqueous solution having a higher water concentration than the scrubbing liquid of the first Venturi stage.

4. The urea prilling tower of claim 1 , wherein the prilling tower is a natural draft urea prilling tower.

5. The urea prilling tower of claim 1 , wherein each of said Venturi ejectors comprises converging part, a throat, and a diverging part, and a nozzle for spraying a liquid into said throat.

6. The urea prilling tower of claim 5 , wherein the gas stream treatment system further comprises a sprayer between a first and a downstream second Venturi stage, for spraying an aqueous solution.

7. The urea prilling tower of claim 1 , wherein the gas stream treatment system further comprises a mist eliminator between a first and a downstream second Venturi stage.

8. The urea prilling tower of claim 5 , wherein the nozzle is arranged inside the converging part.

9. The urea prilling tower of claim 5 , wherein the nozzle is a hydraulic nozzle or a dual fluid injector.

Assignees

• Stamicarbon

Inventors

• Higgins Brian Sayre
• Tate Iii John Marshall
• YATES Robert Arthur
• Pomerleau Marcel Julien
• HEON Jon Michael
• Dirkx Wilfried Marc Renaat
• González Juan Coloma

Classifications

• Y02C20/30

  of perfluorocarbons [PFC], hydrofluorocarbons [HFC] or sulfur hexafluoride [SF6] · CPC title

• B01D47/05 Primary

  by condensation of the separating agent · CPC title

• B01D47/06

  Spray cleaning · CPC title

• C07C273/16

  Separation; Purification · CPC title

• C05C9/00

  Fertilisers containing urea or urea compounds · CPC title