Heat recovery system

Patent metadata

Field	Value
Publication number	US-10914520-B2
Application number	US-201615272562-A
Country	US
Kind code	B2
Filing date	Sep 22, 2016
Priority date	Mar 29, 2011
Publication date	Feb 9, 2021
Grant date	Feb 9, 2021

Abstract

The heat recovery system includes an oven having a treatment air with a treatment air temperature and a treatment air dew point temperature to treat a product or product in process. A zone outlet exhaust waste treatment air following the treatment of the product. A preheating zone includes a preheating inlet for the introduction of preheating air having a preheating air temperature and a preheating air dew point temperature to preheat the product. A transfer duct extends between the zone outlet of the oven and the preheating zone to transfer a portion of waste treatment air from the oven to the preheating zone to create the preheating air to preheat additional product. The preheating air preheats the product in the preheating zone to a product temperature that is at least equal to the treatment air dew point temperature to eliminate surface condensation on the product during treatment in the oven.

First claim

What is claimed is:

1. A heat recovery system for use with multiple ovens to recycle waste treatment air used to treat a product in process in a downstream oven for creating a preheating air to preheat the product in process in a seperate preheating oven prior to entering the downstream oven zone, comprising:
a downstream oven having at least one oven zone for treating the product in process and including a zone inlet for the introduction of a treatment air having a treatment air temperature and treatment air dew point temperature for treating the product in process and a zone outlet for exhausting the waste treatment air following the treatment of the product in process;
an oven duct assembly extending external to the downstream oven from said zone outlet for receiving the exhausted waste treatment air following the treatment of the product in process;
a separate preheating oven disposed upstream of said downstream oven for preheating the product in process prior to entering the at least one oven zone of the downstream oven and including a preheating inlet for the introduction of preheating air having a preheating air temperature and a preheating air dew point temperature for preheating the product in process; and
a transfer duct extending between said oven duct assembly of the downstream oven and said preheating oven for transferring at least a portion of waste treatment air from said oven duct assembly to said preheating oven for creating the preheating air to preheat additional product in process, a second portion of the waste treatment air recirculated in the oven duct assembly of the downstream oven to said zone inlet;
wherein the preheating air preheats the product in process in the preheating oven to a product temperature being at least equal to the treatment air dew point temperature for eliminating surface condensation on the product in process during treatment in said preheating oven;
wherein said preheating oven includes a preheating outlet for exhausting the waste preheating air following the preheating of the product in process;
a preheating duct assembly extending external to the preheating oven from said preheating outlet to said preheating inlet for recirculating the waste preheating air between the preheating outlet and the preheating inlet following the preheating of the product in process; and
wherein the waste preheating air is conditioned in said preheating duct assembly for creating a new preheating air having the preheating air temperature and the preheating air dew point temperature to preheat additional product in process.

2. The heat recovery system as set forth in claim 1 wherein at least a portion of the waste treatment air is conditioned in said oven duct assembly for creating new treatment air to treat additional product in process.

3. The heat recovery system as set forth in claim 2 further including at least one oven exhaust fan being secured to said oven duct assembly for moving the waste treatment air from said zone outlet and introducing ambient air to the waste treatment air to condition the waste treatment air.

4. The heat recovery system as set forth in claim 2 further including an oven duct regulator for controlling the flows of the treatment air, the waste treatment air and an ambient air, through, into and out said oven duct assembly.

5. The heat recovery system as set forth in claim 1 further including an oven exhaust flue extending from said oven duct assembly for bleeding off at least a portion of the waste treatment air from said oven duct assembly.

6. The heat recovery system as set forth in claim 1 further including at least one preheating exhaust fan secured to said preheating duct assembly for moving the waste preheating air from said preheating outlet.

7. The heat recovery system as set forth in claim 1 further including a preheating exhaust flue extending from said preheating duct assembly for bleeding off at least a portion of the waste preheating air from said preheating duct assembly.

8. The heat recovery system as set forth in claim 1 wherein said transfer duct extends between said oven duct assembly and said preheating duct assembly for transferring a portion of the waste treatment air from said oven duct assembly to said preheating duct assembly to condition the waste preheating air with the waste treatment air for creating the new preheating air to preheat additional product in process.

9. The heat recovery system as set forth in claim 8 further including a preheating duct regulator for controlling the flows of the preheating air, the waste preheating air, the waste treatment air and an ambient air, through, into and out said preheating duct assembly.

10. The heat recovery system as set forth in claim 8 further including at least one preheating exhaust fan secured to said preheating duct assembly for moving the waste preheating air from said preheating outlet and for introducing ambient air to the waste preheating air to condition the waste preheating air.

11. The heat recovery system as set forth in claim 1 wherein the preheating air preheats the product in process in the preheating oven to a product temperature being greater than the treatment air dew point temperature for eliminating surface condensation on the product in process during treatment in said downstream oven.

12. The heat recovery system as set forth in claim 1 further including at least one oven exhaust fan being secured to said oven duct assembly for moving the waste treatment air from said zone outlet.

13. The heat recovery system as set forth in claim 1 wherein treating the product in process includes at least one of drying, baking, rehydrating, fermenting or toasting the product in process.

14. The heat recovery system as set forth in claim 1 wherein said downstream oven includes a plurality of oven zones disposed downstream of said preheating oven.

15. The heat recovery system as set forth in claim 1 wherein both said downstream oven and said preheating oven are single pass ovens.

16. A heat recovery system for use in a multi-zone oven to recycle treatment air used to treat a grain based cereal product in a downstream oven zone to condition waste preheating air and create a preheating air for preheating the grain based cereal product in a preheating zone prior to entering the downstream oven zone, comprising:
an oven having at least one oven zone for treating the grain based cereal product and including a zone inlet for the introduction of a treatment air having a treatment air temperature and treatment air dew point temperature for treating the grain based cereal product and a zone outlet for exhausting the waste treatment air following the treatment of the grain based cereal product;
an oven duct assembly extending external to the oven from said zone outlet to said zone inlet for recirculating the waste treatment air from the zone outlet to the zone inlet following the treatment of the grain based cereal product, wherein the waste treatment air is conditioned in said oven duct assembly for creating new treatment air to treat additional grain based cereal product;
a preheating zone disposed upstream of said oven for preheating the grain based cereal product prior to entering the at least one oven zone and including a preheating inlet for the introduction of preheating air having a preheating air temperature and a preheating air dew point temperature for preheating the grain based cereal product and a preheating outlet for exhausting the waste preheating air following the preheating of the grain based cereal product;
a preheating duct assembly extending externa

Assignees

• Kellog Co

Inventors

• Hirzel Nicholson
• Breslin James

Classifications

• Y02P70/10

  Greenhouse gas [GHG] capture, material saving, heat recovery or other energy efficient measures, e.g. motor control, characterised by manufacturing processes, e.g. for rolling metal or metal working · CPC title

• A23B2/90

  by drying or kilning; Subsequent reconstitution · CPC title

• A23B9/08

  Drying; Subsequent reconstitution · CPC title

• A21B1/26

  by hot air · CPC title

• F26B23/002 Primary

  recovered from dryer exhaust gases (F26B23/022 takes precedence) · CPC title