Apparatus and method for evaporating waste water and reducing acid gas emissions

Patent metadata

Field	Value
Publication number	US-9861930-B2
Application number	US-201615141986-A
Country	US
Kind code	B2
Filing date	Apr 29, 2016
Priority date	Jan 2, 2014
Publication date	Jan 9, 2018
Grant date	Jan 9, 2018

Abstract

An apparatus for evaporating waste water and reducing gas emissions includes an evaporator device configured to receiving a portion of flue gas emitted from a boiler unit and waste water to directly contact the flue gas with the waste water to cool and humidify the flue gas and to dry solid particulates within the waste water. In some embodiments, the waste water may be a component of a mixture formed by a mixer device prior to being contacted with the flue gas to humidify and cool the flue gas and dry solids within the waste water. An alkaline reagent as well as activated carbon can be mixed with the waste water prior to the waste water contacting the flue gas. Solid particulates that are dried within the cooled and humidified flue gas can be separated from the flue gas via a particulate collector.

First claim

What is claimed is:

1. A method for evaporating waste water and reducing acid gas emissions, comprising:
adding an alkaline reagent to a waste water to produce alkaline waste water;
transporting a first portion of a flue gas emitted by a combustion unit to an evaporator device such that the first portion of the flue gas bypasses a pre-heater and is contacted by the alkaline waste water to evaporate the alkaline waste water, to reduce acid gas emissions, to produce a cooled and humidified first portion of the flue gas, and to produce dry solid particulates;
separating the dry solid particulates using a particulate collector to obtain separated dry particulates;
feeding a portion of the separated dry particulates to the waste water prior to alkaline waste water contact with the first portion of the flue gas;
transporting a second portion of the flue gas emitted by the combustion unit to the pre-heater to heat a fluid in the preheater to produce a heated fluid supplied to the combustion unit; and
merging the cooled and humidified first portion of the flue gas with the second portion of the flue gas, after the second portion of the flue gas has passed through the pre-heater, to produce a merged flue gas.

2. The method of claim 1 , wherein the alkaline reagent, at least a portion of the separated dry particulates and the waste water are mixed to form a mixture supplied to the first portion of the flue gas for contact to cool and humidify the first portion of the flue gas and to capture acid gas elements within the merged flue gas after the second portion of the flue gas exits the pre-heater and prior to merged flue gas flow into the particulate collector.

3. The method of claim 1 , wherein the alkaline reagent, at least a portion of the separated dry particulates and the waste water are mixed to form a moist powder mixture supplied to the first portion of the flue gas for contact to cool and humidify the first portion of the flue gas and to capture acid gas.

4. The method of claim 1 , further comprising:
using a waste water vessel configured to receive waste water from at least one waste water source and configured to receive the alkaline reagent from an alkaline reagent supply to produce alkaline waste water within the waste water vessel for supply to the evaporator device.

5. The method of claim 1 , further comprising:
using the combustion unit connected to the evaporator device for supply of at least the first portion of the flue gas to the evaporator device;
using the particulate collector connected to the evaporator device to receive at least the cooled and humidified first portion of the flue gas for separation of dry solid particulates from the cooled and humidified first portion of flue gas supplied by the evaporator device.

6. The method of claim 1 , further comprising:
using the particulate collector to supply merged flue gas to a flue gas desulfurization system connected to the particulate collector, for flue gas desulfurization system removal of sulfur oxides from the merged flue gas, with waste water produced in the flue gas desulfurization system supplied to a waste water vessel.

7. The method of claim 1 , further comprising:
using a mixer device configured for mixing the alkaline reagent, the waste water, and at least a portion of the separated dry particulates to form a mixture supplied to the evaporator device.

8. The method of claim 1 , further comprising:
using a conduit of the evaporator device for supply of the cooled and humidified first portion of the flue gas to the particulate collector, with a mixture of the alkaline reagent, the waste water, and at least a portion of the separated dry particulates mixed in a mixer device and supplied to the conduit for contact with the cooled and humidified first portion of the flue gas flowing through the conduit for supply to the particulate collector.

9. The method of claim 1 , further comprising:
using the evaporator device comprising a vessel for receiving the first portion of the flue gas and a mixture of the alkaline reagent, the waste water, and at least a portion of the separated dry particulates, for retention in the vessel of the first portion of the flue gas and the mixture for a pre-specified time period to cool and humidify the first portion of the flue gas and to dry the mixture prior to supply to the particulate collector.

10. The method of claim 1 , further comprising:
monitoring one or more conduits supplying flue gas to the particulate collector using at least one sensor selected from a group of sensors consisting of a flow sensor, a temperature sensor, and a humidity sensor.

11. The method of claim 1 , further comprising:
monitoring one or more conduits supplying flue gas to the particulate collector using one or more temperature sensors to control operations for flue gas cooling to at least a pre-specified temperature.

12. The method of claim 1 , further comprising:
monitoring one or more conduits supplying flue gas to the particulate collector using one or more humidity sensors to control operations for humidifying flue gas to at least a pre-specified humidity level.

13. The method of claim 1 , further comprising:
monitoring one or more conduits supplying flue gas to the particulate collector using one or more flow sensors to control operations for waste water evaporation and acid gas emissions reduction.

14. The method of claim 1 , further comprising:
controlling a mixing device based on monitoring one or more conduits supplying flue gas to the particulate collector, using at least one sensor selected from a group of sensors consisting of a flow sensor, a temperature sensor, and a humidity sensor, for the monitoring.

Assignees

• General Electric Technology Gmbh

Inventors

• Gansley Raymond Raulfs
• Rader Philip C

Classifications

• F23J2217/102

  electrostatic · CPC title

• Y10S203/18

  Control · CPC title

• B01D2252/60

  Additives · CPC title

• C02F2305/12

  Inert solids used as ballast for improving sedimentation (C02F3/1226 takes precedence) · CPC title

• F23J2219/40

  Sorption with wet devices, e.g. scrubbers · CPC title