Preheater for clothes dryer

• US 4,063,590 A
• Filed: 10/22/1976
• Issued: 12/20/1977
• Est. Priority Date: 10/22/1976
• Status: Expired due to Term

• Current Assignee: Christopher L. Mcconnell
• Original Assignee: Christopher L. Mcconnell
• Inventors: McConnell, Christopher L.
• Primary Examiner(s): Davis, Jr., Albert W.
• Application Number:
  US05/734,814
• Time in Patent Office: 424 Days
• Field of Search: 165/164, 165/165, 165/135, 165/DIG. 12, 34/86
• US Class Current: 165/135
• CPC Class Codes: D06F 58/20 General details of domestic laundry dryers D06F59/00 takes precedence
• CPC Class Codes: F28F 3/12 Elements constructed in the shape of a hollow panel, e.g. with channels F28D1/02, F28D1/03 take precedence
• CPC Class Codes: Y10S 165/909 Regeneration

Abstract

The preheater for a clothes dryer preheats ambient air taken into the dryer by heat transfer from hot air discharged from the dryer, thus reducing the energy requirements of the dryer. The preheater includes a box with a heat conductive partition defining a first passage for flow of ambient air into the dryer and a second passage for flow of hot discharge air from the dryer reverse to the ambient air flow so that there is a relatively high temperature difference between the passages for effective heat transfer. Heat is transferred through the partition from discharge air to ambient air, and the partition has a serpentine configuration for increasing its heat exchanging surface area, thus improving heat transfer.

Claims

1. In a preheater for attachment to the back of a clothes dryer which takes in ambient air at the back and discharges moist heated air at the back, the improvement wherein said preheater comprises:

box means having a back with means for attachment to the back of the clothes dryer;

heat conductive partition means dividing said box means into first and second passage means for providing a heat exchange surface between said passage means, said partition means extending substantially vertically when said box means is attached to the back of the clothes dryer with said first passage means next to the back of the dryer said second passage means separated from the back of the dryer by said first passage means, said partition means having a serpentine configuration in horizontal cross-section for increasing the heat exchanging surface area thereof and defining vertical channels in both of said passage means for flow of air in contact with said partition means;

first inlet means for intake of ambient air located substantially at the top of said first passage means, and first outlet means located substantially at the bottom of said first passage means for discharging preheated ambient air into said clothes dryer;

second inlet means for intake of heated air discharged from said dryer into said second passage means located substantially at the bottom thereof, and second outlet means located at substantially the top of said second passage means for flow in said second passage means of the heated discharge air reverse to the flow of the ambient air and exhaust of the discharge air from said second outlet means;

said second inlet means including an inlet plenum opening into said second passage means;

said inlet plenum including diffuser means for diffusing heated discharge air through said second passage means;

said second outlet means including an outlet plenum into which said second passage means opens;

said serpentine partition means being narrower than said box means and defining a space in said box means between said plenums; and

said preheater further including blocking means in said space for blocking flow of air between said plenums except through said second passage means;

said partition means serving to transfer heat from the discharge air to the ambient air in said passage means for preheating the ambient air supplied to the dryer with a relatively high temperature difference between the ambient air and the discharge air throughout said passage means due to the reverse flows thereof;

and said diffuser means comprising a substantially V-shaped member affixed to the front of said box means in said inlet plenum.

2. In a preheater for attachment to the back of a clothes dryer which takes in ambient air at the back and discharges moist heated air at the back, said preheater comprising:

box means having a back wall for attachment to the back of the clothes dryer and a front wall spaced from its back wall;

heat conductive partition means in said box means extending substantially vertically when said box means is attached to the back of the clothes dryer, said partition means in horizontal cross-section extending in serpentine fashion between said back and said front wall of said box means to divide the interior of said box means into alternate substantially vertical ambient air intake passages next to said back wall and substantially vertical heated air discharge passages facing toward said front wall;

means providing air inlets at the upper end of said ambient air intake passages;

said box means defining a heated air inlet plenum which leads into the lower end of said heated air discharge passages and has an inlet in said back wall for receiving heated air discharged from the clothes dryer;

and said box means defining a heated air outlet plenum leading from the upper end of said heated air discharge passages;

the improvement which comprises;

means defining an air outlet opening in said back wall at the lower end of said ambient air intake passages for passing ambient intake air from the latter into the clothes dryer;

and means for insulating said heated air discharge passages at said front wall of said box means said insulating means being engaged between said front wall and the adjacent segments of said heat conductive partition means to close said heated air discharge passages at the front between said plenums for blocking heat transfer from said heated air discharge passages to said front wall of said box means whereby to minimize the loss of heat from said heated air discharge passages through said front wall and thereby enhance the heat exchange from said heated air discharge passages through said heat conductive partition means to said ambient air intake passages for preheating the ambient air going into the clothes dryer.

3. A preheater according to claim 2, and further comprising transverse partition means located in said box means at the lower end of said ambient air intake passages and above said heated air inlet plenum, said partition means blocking said ambient air intake passages from said heated air inlet plenum, and said air outlet in the back wall of said box means at the lower end of said ambient air intake passages being located above said partition means.

4. A prehater according to claim 3, wherein said air outlet in the back wall of said box means is horizontally elongated.