System for recovering waste heat

Patent metadata

Field	Value
Publication number	US-9574829-B2
Application number	US-201013514857-A
Country	US
Kind code	B2
Filing date	Nov 30, 2010
Priority date	Dec 11, 2009
Publication date	Feb 21, 2017
Grant date	Feb 21, 2017

Abstract

Provided is a system for recovering waste heat discharged from distillation columns, incinerators, blast columns, smelting columns, and the like at relatively low temperatures to produce hot water in high efficiency, which can be used in various industrial fields. The investment and operating costs of the waste heat recovery system are relatively low as compared with the conventional systems.

First claim

What is claimed is:

1. A multistage system for recovering waste heat, which comprises:
a first column,
a first steam reboiler which is fluidly connected to a lower part of said first column for supplying heat to the first column,
a first hot water generator which is fluidly connected on a secondary side of the first hot water generator to an upper part of said first column for heating cold water to hot water on a primary side of the first hot water generator by a hot fluid discharged from the upper part of said first column,
a second column,
a second steam reboiler which is fluidly connected to a lower part of said second column for supplying heat to the second column,
a first hot water reboiler which is fluidly connected on a primary side of the first hot water reboiler to said first hot water generator and on a secondary side of the first hot water reboiler to the lower part of said second column, wherein the connection between the first hot water reboiler and the second column forms a first fluid loop; and wherein the first hot water reboiler receives said hot water of temperature 1 from the first hot water generator and supplies heat from said hot water of temperature 1 to the lower part of said second column via the first fluid loop,
a third column,
a third steam reboiler which is fluidly connected to a lower part of said third column for supplying heat to the third column, and
the second hot water reboiler which is fluidly connected on a primary side of the second hot water reboiler to said first hot water reboiler and on a secondary side of the second hot water reboiler to the lower part of said third column, wherein the connection between the first hot water reboiler and the second column forms a second fluid loop; wherein the second hot water reboiler receives said hot water of temperature 2 discharged from said first hot water reboiler after heat is supplied to the second column; and wherein the second hot water reboiler supplies heat from said hot water of temperature 2 to the lower part of said third column via the second fluid loop;
wherein said second column is operated at a temperature higher than the temperature at which said third column is operated; and
wherein the primary side of the hot water generator, the primary side of the first hot water reboiler, and the primary side of the second hot water reboiler are fluidly connected in a third fluid loop.

2. The multistage system of claim 1 further comprising a controller for controlling either or both of the flow rate and the temperatures 1 and 2 of the hot water fed to said first and second hot water reboilers based on the differences in the flow rates and the temperatures 1 and 2 of the hot water fed to and discharged from said first and second hot water reboilers.

3. The multistage system of claim 1 , wherein said first and second hot water reboilers are welded plate heat exchangers.

Assignees

• Yang Hojin
• Won Kidon
• Kim Juntae
• Lee Doojin
• Park Soo Hyun
• Skc Co Ltd

Inventors

• Yang Hojin
• Won Kidon
• Kim Juntae
• Lee Doojin
• Park Soo Hyun

Classifications

• F01K17/06

  Returning energy of steam, in exchanged form, to process, e.g. use of exhaust steam for drying solid fuel or plant · CPC title

• F01K17/02

  for heating purposes, e.g. industrial, domestic (F01K17/06 takes precedence; domestic- or space-heating systems, e.g. central-heating systems, in general F24D1/00, F24D3/00, F24D9/00) · CPC title

• F28D15/00 Primary

  Heat-exchange apparatus with the intermediate heat-transfer medium in closed tubes passing into or through the conduit walls {; Heat-exchange apparatus employing intermediate heat-transfer medium or bodies (F28D17/00, F28D19/00, F28D20/00 take precedence)} · CPC title

• B01D1/2856

  The compressed vapour is used for heating a reboiler or a heat exchanger outside an evaporator · CPC title

• F01K23/064

  in combination with an industrial process, e.g. chemical, metallurgical · CPC title