Combined quenching and scrubbing system with guide tube for an entrained flow gasifying reactor

Patent metadata

Field	Value
Publication number	US-9464248-B2
Application number	US-201414474611-A
Country	US
Kind code	B2
Filing date	Sep 2, 2014
Priority date	Sep 2, 2013
Publication date	Oct 11, 2016
Grant date	Oct 11, 2016

Abstract

A three-stage quenching and scrubbing system for treatment of hot crude gases and liquid slag after an entrained flow gasification. In the first primary stage, cooling and scrubbing water is injected such that slag can no longer adhere to the wall of the central tube and the conversion reaction of the carbon monoxide with water vapor to give hydrogen can proceed to close to the equilibrium. A secondary quenching and scrubbing stage takes the form of a bubble column, and further cooling and the deposition of coarse dust and slag are effected in a water bath. The rest of the treatment is through intensive spraying in a tertiary quenching and scrubbing the gas stage, nozzle rings for deposition of fine slag and partly of fine dust. All three quenching and scrubbing stages enable cooling of the crude gas down to the water vapor dew point determined by the plant pressure.

First claim

The invention claimed is:

1. A crude gas scrubbing system configured and operable for having a high separation level of dust in an entrained flow gasification unit for the reaction of ash-containing fuels with a gasifying agent containing free oxygen to give a crude gas having a high hydrogen content, comprising:
a gasification reactor operable at temperatures of 1200 to 1900° C. and process pressures up to 10 MPa for processing the fuel through the reactor and for converting the fuel to crude gas and liquid slag,
a quencher arranged beneath the gasification reactor, a gas and slag outlet from the reactor into the quencher for transferring the crude gas and liquid slag into the quencher,
a central tube in the quencher and connected to the gas and slag outlet and the central tube also dips into a water bath at a lower end of the quencher,
the central tube has an upper end and a water jet at the upper end is configured to introduce water into the stream of crude gas and slag;
a lower end of the central tube is configured to separate the slag into the water bath while the crude gas rises upward within a bubble column outside the central tube,
a crude gas outlet via which the crude gas leaves the quencher in an upper region of the quencher,
at least one nozzle ring between a surface of the water bath and the crude gas outlet and the nozzle ring is configured to spray water into the crude gas,
a guide tube concentrically surrounding the lower end of the central tube,
wherein the central tube has a double-walled configuration to form an annular channel and cooling water is supplied to a top of the annular channel and leaves an annular gap in the water bath.

2. The crude gas scrubbing system as claimed in claim 1 , wherein the lower end of the guide tube is arranged lower than the lower end of the central tube leaving a gap between the guide tube and the slag discharge at the bottom of the water bath.

3. The crude gas scrubbing system as claimed in claim 1 , wherein an upper end of the guide tube projects above the surface of a water bath.

4. The crude gas scrubbing system as claimed in claim 1 , wherein the control tube and the guide tube are located and configured so that the bubble column forms within an annular space between the central tube and the guide tube.

5. The crude gas scrubbing system as claimed in claim 1 , further comprising a guide tube connecting the central tube to the gas and slag outlet, and a jet for delivering water into the center of the guide tube.

6. The crude gas scrubbing system as claimed in claim 1 , further comprising a guide tube connecting the central tube to the gas and slag outlet, and an injector for recycling cooling water for the guide tube into the hot stream of crude gas and slag at the lower end of the guide tube.

7. The crude gas scrubbing system as claimed in claim 1 , further comprising a pressure casing of the quencher and an inner casing of the quencher located to form an annular gap formed between the casings, such that water fed in at a base rises within the annular gap, overtops an upper edge of the inner casing and runs down an inside of the inner casing as a water film.

8. The crude gas scrubbing system as claimed in claim 1 , wherein the central tube is configured such that a velocity of the crude gas in the central tube is less than 20 m/s.

9. The crude gas scrubbing system as claimed in claim 4 , wherein the annular space is a cavity configured so that the crude gas in the annular space has a mean flow rate of less than 0.5 m/s.

10. The crude gas scrubbing system as claimed in claim 1 , wherein the quencher is configured so that the crude gas is cooled in the quencher down to a water vapor saturation temperature which is determined by a process pressure.

Assignees

• Siemens Ag

Inventors

• Fischer Norbert
• Hannemann Frank
• Just Tino
• Schingnitz Manfred
• Schuld Guido

Classifications

• C10K1/06

  combined with spraying with water {(C10K1/001 takes precedence)} · CPC title

• C10K1/02 Primary

  Dust removal · CPC title

• C10K1/101

  with water only · CPC title

• C10J3/48 Primary

  Apparatus; Plants · CPC title

• C10J3/84

  with means for removing dust or tar from the gas · CPC title