Cracked gas quench heat exchanger using heat pipes

Patent metadata

Field	Value
Publication number	US-2021190435-A1
Application number	US-201716076003-A
Country	US
Kind code	A1
Filing date	Jan 18, 2017
Priority date	Feb 18, 2016
Publication date	Jun 24, 2021
Grant date	—

Abstract

If a cracked gas heat exchanger becomes damaged water may enter the transfer line causing it to rupture. This may be avoided using a heat exchanger having heat pipes to conduct heat from the cracked gas to a cooling device, typically a water cooler to generate steam. The latter (cooling device) is physical separated from the hot cracked gas stream. The heat pipes may be modified at the hot or cold end with fins, ribs, protuberances, pins and the like.

First claim

1 . A heat exchanger for use with a hot fluid stream leaving a high temperature process comprising a hot section and a cold section which have no common or adjoining external surfaces wherein one or more heat pipes extend from the interior of the hot section traverse the open space between the hot section and cold section at an angle of inclination from 10° to 90° and extend into the cold section.

2 . A heat exchanger according to claim 1 , wherein the temperature differential between the hot section and the cold section is not less than 200° C.

3 . The heat exchanger according to claim 2 , wherein the hot section is at a pressure from 85 to 150 kPa gage and a temperature from 800° C. to 1000° C.

4 . The heat exchanger according to claim 3 , wherein the cold section is at a temperature from 250° C. to 600° C. and a pressure from 5 to 9 MPa.

5 . The heat exchanger according to claim 4 , wherein the fluid passing through the hot section is cracked gas.

6 . The heat exchanger according to claim 5 , wherein the fluid in the cold section is water.

7 . The heat exchanger according to claim 6 , wherein the working fluid in the heat pipe is selected from the group consisting of sodium, potassium, and cesium.

8 . The heat exchanger according to claim 7 , wherein the heat pipes have an outer diameter from 1 cm (0.5 inches) to 10 cm (4 inches).

9 . The heat exchanger according to claim 8 , wherein the heat pipe has a length up to 10 meters.

10 . The heat exchanger according to claim 7 , wherein the heat pipe has one or more of internal capillaries and internal wicking.

11 . The heat exchanger according to claim 10 , wherein the end of the heat pipe in the hot section has a surface resistant to coking.

12 . The heat exchanger according to claim 11 , wherein the end of the heat pipe in the hot section has a surface having a thickness from 100 to 5,000 microns comprising from 40 to 60 weight % of compounds of the formula Mn x Cr 3-x O 4 wherein x is from 0.5 to 2 and from 60 to 40 weight % of oxides of Mn and Si selected from the group consisting of MnO, MnSiO 3 , Mn 2 SiO 4 and mixtures thereof provided that the surface contains less than 5 weight % of Cr 2 O 3 .

13 . The heat exchanger according to claim 12 , wherein the heat pipe comprises from about 55 to 65 weight % of Ni; from about 20 to 10 weight % of Cr; from about 20 to 10 weight % of Co; and from about 5 to 9 weight % of Fe and the balance one or more of the trace elements.

14 . The heat exchanger according to claim 13 , wherein the heat pipe further comprising from 0.2 up to 3 weight % of Mn; from 0.3 to 2 weight % of Si; less than 5 weight % of titanium, niobium and all other trace metals; and carbon in an amount of less than 0.75 weight % the sum of the components adding up to 100 weight %.

15 . The heat exchanger according to claim 12 , wherein the heat pipe comprises from 40 to 65 weight % of Co; from 15 to 20 weight % of Cr; from 20 to 13 weight % of Ni; less than 4 weight % of Fe and the balance of one or more trace elements and up to 20 weight % of W the sum of the components adding up to 100 weight %.

16 . The heat exchanger according to claim 15 , wherein the heat pipe further comprising from 0.2 up to 3 weight % of Mn; from 0.3 to 2 weight % of Si; less than 5 weight % of titanium, niobium and all other trace metals; and carbon in an amount of less than 0.75 weight %.

17 . The heat exchanger according to claim 12 , wherein the heat pipe comprises from 20 to 38 weight % of chromium from 25 to 48, weight % of Ni.

18 . The heat exchanger according to claim 17 , wherein the heat pipe further comprising from 0.2 up to 3 weight % of Mn, from 0.3 to 2 weight % of Si; less than 5 weight % of titanium, niobium and all other trace metals; and carbon in an amount of less than 0.75 weight % and the balance substantially iron.

19 . The heat exchanger according to claim 11 , wherein at least a portion of the heat pipe between the hot section and the cold section is helical.

20 . The heat exchanger according to claim 11 , wherein at least a portion of the heat pipe between the hot section and the cold section is in the shape of a “Z”.

21 . The heat exchanger according to claim 9 , wherein there is thermal insulation on the heat pipe between the hot box and the cold box.

22 . The heat exchanger according to claim 10 , wherein the wick is made of nickel, copper, molybdenum, niobium, aluminum, iron, cobalt or alloys based on these metals, and ceramic.

23 . The heat exchanger according to claim 22 , wherein the wick has a pore size from 50 to about 1,000 microns

24 . The heat exchanger according to claim 23 , where in the wick has a bi modal pore size the first pore size is from 300 to 700 microns and the second pore size from 0.5 to 50 microns.

25 . The heat exchanger according to claim 10 having on its hot end, its cold end or both a surface modification selected from the group consisting of fins, ribs, protuberances and pins.

26 . The heat exchanger according to claim 10 , wherein the distance between the hot section and the cold section is from 30 cm to 6 meters.

27 . A heat pipe having on its hot end, its cold end or both a surface modification selected from the group consisting of fins, ribs, protuberances and pins.

Assignees

• Nova Chem Int Sa

Inventors

• Benum Leslie Wilfred
• Clavelle Eric
• Botros Kamal K
• Simanzhenkov Vasily
• Farag Hany Iskandar
• Koselek Michael Edward

Classifications

• F28D15/02

  in which the medium condenses and evaporates, e.g. heat pipes {(heat pipes used in solar heat collectors F24S10/95; in radiators F28D1/0226; in nuclear reactors G21C15/257)} · CPC title

• F28D15/0275 Primary

  Arrangements for coupling heat-pipes together or with other structures, e.g. with base blocks; Heat pipe cores · CPC title

• F28D21/001

  for thermal power plants or industrial processes · CPC title

• F28F21/081

  Heat exchange elements made from metals or metal alloys · CPC title