IP Library › Granted Patent US 12,607,412
Granted Patent B2
US 12,607,412 · App. 18/193,006 · Granted Apr 21, 2026

Exhaust gas heat exchanger with twisted restrictor

Inventors: Rajan Sunilkumar Shah (Eagleview, PA); Stephen B. Miller (Glenside, PA); Robert Jules Pisch (Willow Grove, PA)
Assignee: RB Distribution, Inc.
F28D7/1684F28D21/00F28D2021/008
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Quick Facts
Patent No.
US 12,607,412
App. No.
18/193,006
Granted
Apr 21, 2026
Kind
B2
Abstract

A heat exchanger having selected heat exchanger tubes that includes a flow restrictor that causes a non-linear flow through the heat exchanger tubes.

Claims (34)

1 . A heat exchanger, comprising:

a housing having an inlet face, an outlet face, and a coolant fluid chamber between the inlet face and the outlet face;

a plurality of heat exchanger tubes is mounted within the coolant fluid chamber;

at least one of the heat exchanger tube among the plurality of heat exchanger tubes includes a flow restrictor; and,

the plurality of heat exchanger tubes mounted within the coolant fluid chamber have a first array of heat exchanger tubes with a first diameter and a second array of heat exchanger tubes with a second, smaller diameter.

2 . The heat exchanger according to claim 1 , wherein the flow restrictor rotates the flow within the at least one of the heat exchanger tube about a longitudinal axis in the heat exchanger tube.

3 . The heat exchanger of claim 2 , wherein the flow restrictor is a metallic strip that has a plurality of longitudinal twists.

4 . The heat exchanger according to claim 1 , wherein multiple heat exchanger tubes among the among the plurality of heat exchanger tubes include a flow restrictor.

5 . The heat exchanger of claim 1 , wherein selected heat exchanger tubes in the first array have a flow restrictor.

6 . The heat exchanger of claim 1 , wherein the second array of heat exchanger tubes is nested within the first array of heat exchanger tubes.

7 . The heat exchanger of claim 6 , wherein the heat exchanger tubes in the first array and the heater exchanger tube in the second array are aligned vertically.

8 . The heat exchanger of claim 6 , wherein the heat exchanger tubes in the first array and the heater exchanger tube in the second array are aligned both vertically and horizontally.

9 . The heat exchanger according to claim 1 , wherein the flow restrictor creates at least two flow paths within the at least one heat exchanger tube.

10 . The heat exchanger according to claim 9 , wherein the two separate flow paths are helical flow paths extending around a longitudinal axis of the at least one heat exchanger tube.

11 . The heat exchanger according to claim 1 , further comprising: a flow restrictor in each of the plurality of heat exchanger tubes.

12 . The heat exchanger according to claim 11 , wherein the plurality of heat exchanger tubes mounted within the coolant fluid chamber have a first array of heat exchanger tubes with a first diameter and a second array of heat exchanger tubes with a second smaller diameter.

13 . The heat exchanger of claim 11 , wherein the flow restrictor in each of the plurality of heat exchanger tubes is twisted along the flow restrictor's axial length by approximately 450 degrees.

14 . A heat exchanger, comprising:

a housing having an inlet face, an outlet face, and a coolant fluid chamber between the inlet face and the outlet face;

a plurality of heat exchanger tubes is mounted within the coolant fluid chamber;

at least one of the heat exchanger tube among the plurality of heat exchanger tubes includes a flow restrictor; and,

at least one backpressure reducing tube in the housing.

15 . The heat exchanger of claim 14 , wherein a wall within the housing separates the at least one backpressure reducing tube and the coolant fluid chamber.

16 . A heat exchanger tube assembly for an exhaust gas heat exchanger, the assembly comprising:

an elongated tube with a predetermined length; and,

a twisted flow restrictor that is secured within the elongated tube and causes exhaust gas through the elongated tube to have a non-linear flow through the elongated tube, wherein the twisted flow restrictor creates two separate flow paths through the elongated tube.

17 . The heat exchanger tube according to claim 16 , wherein the non-linear flow is about a longitudinal axis of the elongated tube.

18 . The heat exchanger tube according to claim 16 , wherein the two separate flow paths are helical flow paths extending around a longitudinal axis of the elongated tube.

19 . The heat exchanger tube according to claim 16 , wherein the twisted flow restrictor is metallic.

20 . The tube according to claim 16 , wherein the twisted flow restrictor is twisted along a longitudinally axis between a first and a second end by approximately 450 degrees.

21 . A tube kit for use in assembling a heat exchanger, the kit comprising:

a first plurality of elongated tubes that have a predetermined length, a first interior diameter; and, a twisted flow restrictor that is secured within the first interior diameter; and,

a second plurality of elongated tubes that have a second interior diameter that is less than the first interior diameter and the second plurality of elongated tubes is unrestricted.

22 . The tube kit of claim 21 , wherein the twisted flow restrictor causes a non-linear flow the flow through the first plurality of elongated tubes.

Assignments (2)
SECURITY AGREEMENT Recorded Jun 16, 2026
From: RB DISTRIBUTION, INC.; SUPER ATV, LLC
To: BANK OF AMERICA, N.A., AS ADMINISTRATIVE AGENT
Reel/Frame 075844/0897 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Mar 30, 2023
From: SHAH, RAJAN SUNILKUMAR; MILLER, STEPHEN B.; PISCH, ROBERT JULES
To: RB DISTRIBUTION, INC.
Reel/Frame 063171/0883 →
Continuity (1)
Related Publication 20240328720A1 · Oct 3, 2024
References Cited (4)
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US 7243707B2 · Brost · 2007 [cited by applicant]
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