Method for making brazed heat exchanger and apparatus

A technology of heat exchanger and structure, which is applied in the improvement field of metal heat exchanger, and can solve problems such as difficulties

Inactive Publication Date: 2013-05-01
UOP LLC
View PDF19 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Maintaining the integrity and effectiveness of the EBL, especially the porous structure provided by the artificially bonded metal particles, is more difficult to achieve brazing during the second hotter heat treatment
This difficulty is due to the fact that there are no commercially available brazed heat exchangers with an EBL in the boiling channel

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Method for making brazed heat exchanger and apparatus
  • Method for making brazed heat exchanger and apparatus
  • Method for making brazed heat exchanger and apparatus

Examples

Experimental program
Comparison scheme
Effect test

Embodiment I

[0030] The enhanced boiling powder was obtained by mixing 83.6 wt-% Al3003 alloy, 8.4 wt-% brazing flux containing potassium aluminofluorate and 8.0 wt-% aluminum alloy 4047 brazing powder. An adhesive comprising 38 wt-% polyisobutylene sold by Clifton Adhesives under the trade designation CS-200A3 and 62 wt-% hydrocarbon (VARSOL) light kerosene solvent was mixed and brushed onto the walls of a triple tube comprising aluminum alloy 3003 superior. The enhanced boiling powder is then sprayed onto the binder and heated in nitrogen in a small furnace. Each coated tubular wall was heated to 621°C (1150°F) for 9 minutes. The binder and solvent evaporate and leave an EBL 0.3-0.4 mm (10-15 mil) thick. The obtained EBL has a porous tissue structure and is determined to have a mass greater than 204.418kJ / hr / m 2 K(10,000BTU / hr / ft 2 °F) boiling heat transfer coefficient.

Embodiment II

[0032] The two metal tubular walls were coated with the binder described in Example I and the enhanced boiling powder. Each metal tubular wall was heated to a brazing temperature of 623°C (1153°F) in a closed still at approximately atmospheric pressure under a controlled nitrogen atmosphere and then cooled.

[0033] The first tubular wall was heated and cooled over a period of 48 minutes. The first tubular wall is tested and determined to have greater than 204,418 kJ / hr / m 2 K(10,000BTU / hr / ft 2 °F), which is large enough for a surface with an EBL. The first tubular metal wall was then subjected to a second calcination by heating the first tubular metal wall to 593°C (1100°F) and holding it at that temperature for 24 hours before cooling to Vacuum brazing of the entire heat exchanger core is performed. Visual observations indicated that the quality of the EBL was not affected. The first tubular metal wall was again measured and determined to have a mass greater than 204,418...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

The invention discloses a heat exchanger, which comprises a boiling channel and a cooling channel formed by the opposite sides of metal walls. Layers of brazing material interposed between the metal walls and spacer members bond the various elements of the heat exchanger together. An enhanced boiling layer (EBL) comprising metal particles bonded to each other and to metal walls provides nucleated boiling pores to enhance heat transfer. The melting point of this EBL is higher than that of the brazing material. The invention also discloses a method for assembling the heat exchanger.

Description

technical background [0001] The present invention relates to an improved method for manufacturing metal heat exchangers with high thermal conductivity. More specifically, the present invention relates to an improved method for manufacturing brazed heat exchangers including reinforced boiling surfaces. [0002] In cryogenic, smelting and chemical applications, heat exchangers used in reboiler-condensers generally come in two configurations. One type of heat exchanger currently in use is the vertical shell and tubular heat exchanger. In order to achieve a sufficiently high degree of heat transfer with relatively low temperature differences, an enhanced boiling layer (EBL) is used. EBLs generally have a structure that includes many pores that provide boiling nucleation sites, thereby promoting boiling. EBL is applied on the inside of each tube, and longitudinal grooves are provided on the outside of each tube to facilitate heat transfer. [0003] Enhanced boiling layers for h...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Patents(China)
IPC IPC(8): F28F13/18F28D9/00F25J3/00F25J3/04
CPCF25J2250/02F25J2250/20F25J2290/32F25J2290/44F28D9/0062F28F13/18F28F13/187F28F21/081F28F21/089F28F2275/04F28F2250/108Y10T29/4935F25J5/005F28D9/00F28F13/00F25J5/002F25J3/04412
Inventor P·S·奥尼尔老·D·P·赫尔德T·J·戈德里
Owner UOP LLC
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap