Honeycomb regenerator

• US 6,210,645 B1
• Filed: 01/25/1996
• Issued: 04/03/2001
• Est. Priority Date: 01/25/1995
• Status: Expired due to Term

• Current Assignee: NGK Insulators Limited
• Original Assignee: NGK Insulators Limited
• Inventors: Kotani, Wataru, Kumazawa, Kazuhiko
• Primary Examiner(s): Straub, Gary P.
• Application Number:
  US08/591,117
• Time in Patent Office: 1,895 Days
• Field of Search: 422/171, 422/206, 428/116, 502/439, 502/128, 502/134, 502/153, 501/119, 501/106, 165/9.2, 165/905, 165/901, 165/902, 165/DIG. 31, 165/DIG. 46, 165/DIG. 396
• US Class Current: 422/206
• CPC Class Codes: C03B 5/237 Regenerators or recuperators specially adapted for glass-melting furnaces
• CPC Class Codes: F28D 17/02 using rigid bodies, e.g. of porous material
• CPC Class Codes: Y02P 40/50 Glass production, e.g. reusing waste heat during processing or shaping
• CPC Class Codes: Y10S 165/037 having flow diverting means, e.g. valve to selectively control flow through storage mass
• CPC Class Codes: Y10S 165/042 Particular structure of heat storage mass
• CPC Class Codes: Y10S 165/905 Materials of manufacture

Abstract

A honeycomb regenerator is constructed by (a) honeycomb structural bodies arranged in a high temperature portion, in which a temperature is over 1250° C. during a normal operation, made of aluminum-titanate or a combination of aluminum-titanate and mullite, and (b) honeycomb structural bodies arranged in a low temperature portion, made of cordierite and/or mullite, or by (a) honeycomb structural bodies arranged in a high temperature portion, to which an exhaust gas having a high temperature is contacted, made of aluminum-titanate or a combination of aluminum-titanate and mullite, (b) honeycomb structural bodies arranged in a middle temperature portion made of alumina and (c) honeycomb structural bodies arranged in a low temperature portion made of one material or a combination of materials selected from a group of cordierite, mullite and a porcelain. The honeycomb regenerator according to the invention can perform a heat exchanging operation effectively even in an exhaust gas having a high temperature and also in an exhaust gas having a high temperature and a corrosive property.

Claims

1. A honeycomb regenerator for recovering waste heat in an exhaust gas by passing an exhaust gas and a gas to be heated alternately therethrough, said honeycomb structural regenerator, comprising:

first honeycomb structural bodies comprising aluminum-titanate as a main crystal phase or a combination of aluminum-titanate and mullite and being stable at a temperature of at least 1250°

C.; and

second honeycomb structural bodies, arranged adjacent said first honeycomb structural bodies in a direction parallel to a gas passing direction, comprising cordierite and/or mullite as a main crystal phase.

2. The honeycomb regenerator according to claim 1, wherein the size of said first honeycomb structural bodies along a perimeter portion thereof is smaller than the size of said first honeycomb structural bodies arranged at a center portion residing within the perimeter portion.

3. The honeycomb regenerator according to claim 1, wherein MgO and Fe₂O₃ are added in said aluminum-titanate.

4. A honeycomb regenerator for recovering waste heat in an exhaust gas by passing an exhaust gas and a gas to be heated alternately therethrough, said honeycomb structural regenerator, comprising:

first honeycomb structural bodies arranged in a first portion and comprising aluminum-titanate as a main crystal phase or a combination of aluminum-titanate and mullite;

second honeycomb structural bodies, arranged in a second portion adjacent said first honeycomb structural bodies in a direction parallel to a gas passing direction, comprising alumina as a main crystal phase and being stable at a temperature of at least 1250°

C.; and

third honeycomb structural bodies, arranged in a third portion adjacent said second honeycomb structural bodies in a direction parallel to a gas passing direction, comprising at least one material selected from the group consisting of cordierite, mullite and a porcelain having a corrosion resistivity.

5. The honeycomb regenerator according to claim 4, wherein said first honeycomb structural bodies comprise aluminum-titanate as a main crystal phase, said second honeycomb structural bodies comprise alumina as a main crystal phase, and said third honeycomb structural bodies comprise cordierite as a main crystal phase.

6. The honeycomb regenerator according to claim 4, wherein said aluminum-titanate includes 4˜

10 wt % of MgO and 2˜

10 wt % of Fe₂O₃.

7. The honeycomb regenerator according to claim 6, wherein a thermal expansion coefficient of said first honeycomb structural bodies comprising aluminum-titanate as a main crystal phase or a combination of aluminum-titanate and mullite is under 1.0×

10<sup>−

6</sup>/°

C. in a temperature range of 40˜

800°

C.

8. The honeycomb regenerator according to claim 4, wherein said third honeycomb structural bodies comprise porcelain honeycomb structural bodies located at a position wherein, when exhaust gas is passing therethrouqh, a temperature is under a dew point of an acid included in said exhaust gas.

9. The honeycomb regenerator according to claim 4, wherein a dimension of said first honeycomb structural bodies along a perimeter portion to which an exhaust gas having a high temperature may be contacted is smaller than that of said first honeycomb structural bodies arranged at a center portion.