US 3806310 A
A method and apparatus for drying carpets and the like wherein wet carpet is passed along its length through a housing along a rectilinear path, hot air is passed from one side of the path through the carpet and the air is recirculated from the other side of the carpet about the side edges of the carpet. The air is heated after it has passed through the carpet prior to being recirculated, and that portion of the air which is passed through the carpet first entering the housing is exhausted to the atmosphere. The heating of the air is accomplished with open flame burners which are either natural gas fired or fuel oil fired, or a combination of gas and oil fired.
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Description (OCR text may contain errors)
United States Patent 91 Brock [4 ]*Apr. 23, 1974 [5 slDE FIRED CARPET DRYING METHOD AND APPARATUS  Inventor: James Donald Brock, Chattanooga,
 ,Assignee: Texile Systems, Inc., Summit, Tenn.
[ Noticei The portion of the term of this patent subsequent to Feb. 15, 1990, has been disclaimed.
 Filed: Feb. 22, 1972 21 App], No.: 227,841
 US. Cl 432/59, 432/8, 34/41, 34/155, 34/216  Int. Cl.....-., F26b 3/32  Field of Search.......... 263/3, 8; 34/23, 155,41, 34/158, 212, 216, 223, 219, 220,184,225
'  References Cited UNITED STATES PATENTS 3,743,474, 7/1973 Brock 432/8 3,641,681 l 2/1972 Brock 34/41 3,092,166 6/1963 Shepherd... 431/353 3,264,752 8/1966 Hunter 34/229 3,242,527 3/1966 Rosenberg 263/3 3,371,428 3/1968 Thygeson 3 ,362,087 1/1968 Brock 2,775,046 1 2/ 1956 Kabelitz 7 3,199,223 8/1965 Carlson 34/41 Primary Examiner-John J Camby Assistant Examiner--l-lenry C. Yuen Attorney, Agent, or Firm-Dunlap, Laney, Hessin &
Dougherty [57 7 ABSTRACT A method and apparatus for drying carpets and the like wherein wet carpet is passed along its length through a housing along a rectilinear path, hot air is passed from one side of the path through the carpet and the air is recirculated from the other side of the carpet about the side edges of the carpet. The air is heated after it has passed through the carpet prior to being recirculated, and that portion of the air which is passed through the, carpet first entering the housing is exhausted to the atmosphere. The heating of the air is accomplished with open flame burners which are either natural gas fired or fuel oil tired, or a combination of gas and oil fired.
'15 Claims, 4 Drawing Figures PATENTEDAPR 23 1974 3806310 sum 2 0F 2 SIDE FIREDCARPET DRYING METHOD AND APPARATUS CROSS REFERENCE ,TO RELATED APPLICATION Related subject matter is disclosed in the Applicants U.S. Patg No. 3,641,681, Carpet Dryer, issued Feb.
BACKGROUND OF THE INVENTION In the drying of continuous lengths of carpets and similar continuousporous materials, various devices have been developed for forcing heated air through the carpet material, recirculating the heated air, and continuously exhausting a portion of the recirculated air.
have been difficult to mount and cannot be practically serviced or removed from the housing for repair or replacement. Typically, theheating elements have been closed tube heat exchangers which are expensive and inefficient.
SUMMARY OF THE INVENTION Briefly described, the present invention comprises a dryer for drying continuous carpet material and the like which functions to force a high velocity heated stream of air through the carpet as the carpet initially enters the dryer housing, and subsequently flows heated air throughthe carpetlat a lower velocity. The air initially forced through the carpet at high velocity is subsequently exhausted from the housing without recirculating through the. housing, while the air subsequently forced through the carpet is continuously recirculated and reheated untilexhausted through the exhaust system. This effectively removes the wettest. air and coolest air from the housing and rapidly dries the carpet entering the housing. The air recirculated through the carpet is heated in a heating chamber or zone oflow air pressure beneath the path of the carpet by open flame burners, eithergas fired or fuel oil tired, and the air moves around the edges of the'carpet through blowers to ahigh pressure zone above the carpet. The pressure differential across the carpet causes the air to flow through the carpet. Part of the same, body of air moved to the high pressure zone above the carpet is drawn throughthe carpet at the entrance of the housing, so that the heating means in the low pressure zone functions to heat all of the air flowing through the housing and no further heating elements are required. The low pressure air zone beneath the path of thecarpet is substantially unencumbered with air ducts tubes, etc., and the housing .is assembled in two sections at the initial construction site and shipped in sections to the erection site where it is expediently erected.
The burners can utilize either natural gas or fuel oil, or possibly another liquid or gas fuel, whichever fuel desired.
r I might be available or less expensive at the erection site. Also, a mixture of liquid and gasfuels can be used, if'
Thus, it is an object of this invention to provide a method and apparatus for drying carpets and the like which initially heats the carpet as it moves along a path with a high velocity flow of heated air to rapidly remove moisture from the carpet material, and subsequently continues the drying process by passing heated air ata lower velocity through the carpet material.
Another object of this invention is to provide a carpet dryer which recirculates the drying air through the carpet and reheats the recirculating air on each cycle with a minimum of air ducts and heating units.
Another object of this invention is to provide a carpet dryer that utilizes fuel oil or natural gas or other fuels to provide an open flame to heat the air fordrying the carpet. 1
Another object of this invention is to provide apparatus for drying carpet which is inexpensive to initially construct, install, and operate, which functions to dry carpet at a rapid rate without any substantial hazard of damaging the carpet, and which is efficient and effective in its operation.
Other objects, features and advantages of the present invention will become apparent upon reading the following specification when taken in conjunction with the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a side elevational view, in cross section, of
the carpet dryer, showing the carpet as it passes from DESCRIPTION OF A PREFERRED EMBODIMENT Referring now in more detail to the drawing, in which like numerals indicate like parts throughout the several views, FIG. 1 shows carpet dryer 10 which includes insulated housing 11, tenter mechanism 12, recirculating air blower assemblies 14, 15, 16, and 17, exhaust air blower assemblies Hand 19, and burner assemblies 20 and 21. Insulated housing 11 comprises front wall 22, back wall 24, bottom wall 25, side walls 26 and 28, and top wall 29. Entrance partitions 30 are positioned closely adjacent front wall 22 and extend from bottom wall 25 up toward the upper flight of tenter mechanism 12. Side partitions 31 and 32 are positioned closely adjacent side walls 26 and 28 and also extend up toward the upper flight of tenter mechanism 12. Front wall 22 defines exhaust openings 34 and 35, and blowers 36 and 37 of exhaust air blower assemblies 18 and 19 have their inlets in communication with openings 34 and 35. Blowers 36 and 37 exhaust air into duct work 38 and 39 which turns inwardly of housing 11 and communicates with corner voids 40 and 41 formed by the extension of entrance partitions 30 and side partitions 31 and 32. The upper ends of corner voids 40 and 41 are open, and duct work (not shown) is usually connected to the upper ends and functions to flow the exhaust air away from the carpet dryer. With this arrangement, entrance partitions 30 and front wall 22 form exhaust or blow down conduits 42 which have their entrances located at the upper flight of tenter mechanism 12.
Side walls 26 and 28 define impeller openings 44, 45, 46, and 47, and side partitions 31 and 32 define air openings 48, 49, 50, and 51. Impellers 54, 55, 56, and 57 are mounted in impeller openings 4447 with their inlets extending through air openings 48-51. With this arrangement, recirculating conduits 59 and 60 are defined between side partition 31 and side wall 26 and side partition 32 and side wall 28, respectively. When impellers 54-57 are rotated at high angular velocities, a flow of air is created from the area below tenter mechanism 12 within housing 11 through impellers 54-57 into recirculating conduits 59 and 60 to the area above tenter mechanism 12 below top wall 29.
Tenter mechanism 12 comprises a pair of endless chains 61 and 62 that are spaced apart and extend around feed sprockets 64 and delivery sprockets 65. As is shown in FIG. 4, each tenter chain is carried in chain guides 66. Chain guides 66, feed sprockets 64 and delivery sprockets 65 are movable toward and away from each other by means of hanger mechanism 68 and 69 within housing 11 and support mechanisms 70 and 71 adjacent feeder sprockets 64 and delivery sprockets 65. As is shown in FIG. 3, hanger mechanisms 68 and 69 comprise roller mounted hanging blocks 72 suspended from rail 74 within housing 11, and oppositely threaded turning shafts 75. When shafts 75 are rotated, hanging blocks 72 move toward or away from each other, thereby carrying chain guides 66 and tenter chains 61 and 62 toward or away from each other. Thus, the spacing between tenter chain 61 and 62 is variable.
As is shown in FIG. 1, front wall 22 defines carpet inlet opening 78 which is in alignment with the upper flights of tenter chains 61 and 62, and back wall 24 defines carpet outlet opening 79 arranged in a similar manner. Carpet 80 is extended over guide roller 81, beneath guide rollers 82 and 83 so that its edges are impaled by the pins of tenter chains 61 and 62 and carried with the upper flights of the tenter chains. The carpet enters carpet opening 78 of housing 11 and passes with the upper flights of tenter chains 61 and 62 until it emerges from outlet opening 79, where it is guided beneath guide roller 84 and over guide roller 85. Thus, the passage of carpet 80 through the housing is effective to divide housing 11 into low air pressure zone or chamber 86 below the path of the carpet and high air pressure zone or chamber 87 above the path of the carpet. In order to isolate low air pressure zone 86 from high air pressure zone 87, overlapping sliding plates 89 are connected to hanging blocks 72 in the upper edge of side partitions 31 and 32. Thus, when hanging blocks 72 are moved toward or away from each other, sliding plates 89 will move with the hanging blocks 72 and prevent air from flowing around the edges of carpet 80 from high air pressure chamber 87 toward low air pressure chamber 86.
The two open flame gas burner assemblies and 21 are identical and each comprises an outer cylindrical burner can 90, and an inner cylindrical burner can 91. Burner cans 90 and 91 are each connected to support plate 92, and the support plate 92 of each burner assembly is connected to the outside surface of the sidewall 26 or 28 of the dryer housing. The outer cylindrical burner can 90 extends from its support plate 92 and the sidewall 26 or 28 through side partition 31 or 32 and projects into the housing 11. Inner burner can 91 is shorter and of smaller diameter than outer burner can 90, and forms with the outer burner can an annular space 93. Burner 93 is located behind support plate 92 outside the housing and communicates with flared baffle 94 inside inner burner can 91. Air inlet conduit 95 communicates with burner 93 and natural gas conduit 96 and fuel oil conduit 97 communicate through valve 98 with burner 93. A conventional igniter (not shown) is present in burner 93 for the purpose of igniting the natural gas in the burner.
Openings 99 are defined in outer burner can 90, and sliding louvers 100 are arranged to cover the openings. The louvers 100 are adjusted by means of handles 102 which are connected at one of their ends to the louvers 100 and extend through the side wall of the housing. Several opening-louver arrangements can be provided around the periphery of burner can in the recirculating conduits 59 and 60. Thus, air can flow to burner cans 90 and 91 through air inlet conduit and also through the opening-louver arrangements 99 and from recirculating conduit 59 and 60.
Housing-ll is divided into two sections, section 11a and section 11b by central seam 106 in top wall 29, seams 107 and 108 in front and back walls 22 and 24, and entrance partition 30 is divided at 109 into two separate sections. The center-line of bottom wall 25 slopes in a downward direction (FIG. 3) and each half thereof joins to the bottom flange of channel beams 110 and 111. When housing 11 is initially assembled, it is assembled in two sections and subsequently shipped to its site of erection. Upon reaching the site of erection, the seams 106, 107, 108, and 109 and channel beams 110 and 111 are placed in abutment and connected together. The lighter air exhaust blower assemblies 18 and 19 are attached to front wall 22 at the construction site and shipped with the housing while the heavier recirculating air blower assemblies 14, 15, 16, and 17 usually are individually shipped and subsequently connected to housing 11 at the erection site.
OPERATION When carpet dryer 10 is put into operation, carpet 80 is fed over roller 81, beneath rollers 82 and 83 so that its side edges become impaled upon the pins of tenter mechanism 12 and are passed toward housing 11, through carpet inlet opening 78 of front wall 22, through housing 11, and ultimately out of carpet outlet opening 79 in back wall 24. Burner assemblies 20 and 21 are ignited to create open flames in low air pressure chamber 86, and recirculating air blower assemblies 14-17 are energized to create an air flow from low air pressure chamber 86 to high air pressure chamber 87 through recirculating conduits 59 and 60 about the side edges of carpet 80. Also, exhaust air blower assemblies 18 and 19 are energized to create a flow of exhaust air into blow down conduit 42 and back up through corner voids 40 and 41 of housing 11 to the atmosphere.
The burner assemblies 20 and 21 function to create an open flame inside outer cylindrical burner can 90. The flame will usually protrude out the end of the outer burner can 90 toward the middle portion of the housing 1 1, depending upon the amount of fuel and air supplied to the burner assemblies. The air flow to the burner assemblies and the combustion of the fuel and air causes the heat and the gases of combustion to be projected toward the middle of the housing. Moreover, if one or more of the openings 99 in the outer burner can 90 are opened by sliding their louvers 100 away from the openings, a portion of the high pressure air in the recirculating conduits 59 and 60 will enter the outer burner can through the openings 99 and pass into the annular space between theouter burner canand the inner burner can and then be projected along the length of the outer burner can into the dryer housing. This further assists the projection of the flame into the housing and supplies additional oxygen to cause complete combustion of the fuel. in addition, the inner burner can 91- will be cooled, at least to some extent, by the air entering the openings 99 of the outer burner can and passing into the annular space 92. 1
' a The flame and intense heat emerging from the burner convection. Since the air generally flows in a downward direction through the carpet and then turns ina lateral direction toward the inlet of the blower assemblies, the heat emergingfrom the burner assemblies will tend to turn about in the opposite directions and flow toward .the inlet of the blower assemblies. With this flow pat- 1 blower assemblies.
i The air passing through the recirculating conduits 59.
' and 60 will passabout the portions of the outer burner cans 90 which extend through the recirculating conduits. This further heats the air as it is being recirculated, prevents the burner cans from becoming overheated, and reduces the amount of heat transferred to the dryer housing by conduction.
The burner assemblies can be charged with natural gas or with fueloil, or by a combination of natural gas or fuel oil, or possibly by other combustible fluids. In the present embodiment of the invention, the burner assemblies will be initially ignited with the use of natural gas and fuel oil will be subsequently introduced to the burner assemblies through adjustment of the valves 98. Thus, a mixture of the fuels can be utilized. If one of the fuels is in short supply, the other fuel can be utilized, if available. For instance, if the supply of natural gas is at a low pressure, as for instance in the winter months, the burner assemblies can operate exclusively on fuel oil or can utilize a mixture of natural gas and fuel oil.
In one embodiment of the invention, recirculating air blower assemblies 14-17 are constructed so that they each move approximately 30,000 cubic feet per minute from low air pressure chamber86 through recirculating conduits 59 and 60 to highair pressure chamber 87. This functionsto move approximately l20,000 cubic feet per minute of air through the carpet passing through housingll. Exhaust air blower assemblies 18 and 19 are each constructed to move approximately 6,000 cubic feet per minute of air from high air pres sure chamber 87 down through carpet 80 into blow down conduit 42, and ultimately back up through corner voids 40 and 41. Thus, approximately 12,000 cubic feet per min uteof heated air moves down through the carpet as it initially enters housing 11. The spacing of entrance partition 30 from front wall 22 is approximately one foot, while the distance between entrance partition 30 and back wall 24 is approximately 15 feet. The distance between side partitions 3l and 32 is approximately 20 feet.
The approximate velocity of air flowing through the carpet for the disclosed dryer is computed as follows:
At blow down conduit 42: Vel VOL/Length, X Width =12,000/1 X w For carpet widths of l5, l2 and 9 feet, the respective velocities would be 800, 1,000 and .1 ,333 feet per minute. 1 At low air chamber 86: Vel 120,000/15 X w For carpet widths of l5, l2 and 9 feet, the respective Vol lLength X Width velocities would be 433, 666 and 888 feet per minute.
The ratio of air velocities through the carpet at the blow down conduit as compared to that at the low air chamber is computed by:
When the tenter chains are moved apart to a wide position to carry wide carpet through the housing the ten ter drive mechanism (not shown) is operated at a slow speed; and when the tenter chains are moved together to a narrow position to carry narrow carpet through the housing the tenter drive mechanism is operated at a faster speed. This allows approximately the same volume of drying air to pass through each square foot of carpet. 1
The initial fblow down of the carpet is established as the carpet initially enters the housing and is in its dampest and coolest condition. Theresult is that the high velocity initial blow down rapidly heatsthe carpet and removes a large amount of moisture from the carpet. Moreover, the air passing through the carpet into blow down conduit 42 becomes the wettest and coolest air in housing 11 and is immediately exhausted from As the carpet first enters housing 1 1, it carries more moisture and is therefore more dense than it is when, it makes its exit from the housing. Thus, the initial blow down and heat upof the entering carpet takes place on the denser portion of the carpet, where the air is harder to urge through the carpet material. Thus, a higher air pressure differential is required Ito create the blow down of the carpet.
The make up air required to replace hausted through blow down conduit 42 and its exhaust air blower assemblies 18 and 19 is fed in through burner assemblies 20 and 21 and in through carpet openings 78 and 79 in the front wall 22 and back wall 24. Of course, since low air pressure exists in blow down conduit 42 and low air pressure chamber 86, the carpet will tend to be urged in a downward direction by the higher air pressure in high air pressure chamber 87. This causes the carpet 80 to tend to drag over the bottom edges of carpet openings 78 and 79 to more effecthe air being extively close the low pressure chambers while permitting more air inflow into upper air pressure chamber 87. Of course, carpet openings 78 and 79 are gauged to admit primarily only the carpet thickness and to minimize the air inflow at these points, so that most of the make up air will enter housing 11 through burner assemblies and 21. Also, support rollers 67 within housing 11 further support carpet 80 and prevent the pressure differential across the carpet from causing the carpet to sag.
While the carpet passing through the housing is dried principally by air flow through the carpet, it will be understood that the open flames emitted from burner assemblies 20 and 21 will function to dry the carpet by radiation, thus speeding up the drying of the carpet.
While this invention has been described in detail with particular reference to preferred embodiments thereof, it will be understood that variations and modifications can be effected within the spirit and scope of the invention as described hereinbefore and as defined in the appended claims.
1. A dryer for carpet and the like comprising a substantially closed housing including a front wall, a back wall, side walls, a bottom wall and a top wall, a carpet inlet opening defined in said front wall, a carpet outlet opening defined in said back wall, conveyor means for moving carpet along a predetermined path through said inlet opening into said housing and through said outlet opening out of said housing, a first air zone defined in said housing above said path and a second air zone defined in said housing below said path, partition means positioned in said housing below said path adjacent said front wall and defining an air exhaust conduit means, side partitions extending parallel to each side wall and forming with the side walls air recirculating conduits; air recirculating means for continuously recirculating air from said second air zone through said recirculation conduits in an upward direction about the side edges of the carpet to the first air zone and then in a downward direction through the carpet as the carpet moves along said path, open flame burners each including a generally cylindrical shield extending through one of said recirculation conduits and arranged to heat the air in the second air zone below the carpet, air exhaust means in communication with said exhaust conduit means for inducing air to move in a downward direction from said first air zone through the portion of the carpet first entering said housing and through said exhaust conduit means.
2. The dryer of claim 1 and wherein said air exhaust means is constructed and arranged to flow air through the carpet moving along said path at a higher velocity than said air recirculating means.
3. The dryer of claim 1 and wherein said open flame burners comprise gas-fired burners.
4. The dryer of claim 1 and wherein said open flame burners comprise fuel oil-fired burners.
5. The dryer of claim 1 and wherein said open flame burners include means for charging the burners with a mixture of natural gas and fuel oil.
6. The dryer of claim 1 and wherein said housing comprises a sectional two piece housing having a connecting seam extending upwardly along its side walls and across its top wall and bottom wall whereby said housing can be assembled at a centralized construction point and shipped in two sections to an erection site.
7. The dryer of claim 1 and wherein said conveyor means comprises a tenter mechanism with conveying chains movable toward and away from each other to accommodate carpets of various widths, and separating means movable with said conveying chains for separating said first air zone from said second air zone on the sides of the conveying chains away from the carpet and preventing air from flowing from said first air zone around the side edges of the carpet into said second air zone.
8. The dryer of claim 1 and further including filter means positioned down stream of said air recirculating means for filtering the air as the air is recirculated from said second air zone to said first air zone.
9. The dryer of claim 1 and wherein said air recirculating means comprises fan means adjacent each side wall and positioned at a level below said path and constructed to flow air from said second air zone toward both side walls of said housing and around both edges of the carpet moving through said path and into said first air zone, and wherein said air exhaust means comprises fan means adjacent said front wall and positioned at a level below said path. 7
10. A dryer for carpet and the like comprising a housing, conveying means for moving carpet along its length through a predetermined path in said housing, means for flowing air in said housing at a predetermined temperature from one side of the carpet through the portion of the carpet first entering said housing at a predetermined velocity at a first position along said path and exhausting the air to the atmosphere or the like, means for flowing air in said housing at approximately the same predetermined temperature from said one side of the carpet through the carpet at a velocity lower than said predetermined velocity at a second position along said path and recirculating the air back to said one side of the carpet, and heating means arranged to project an open flame from the sides of said housing toward the middle portion of said housing below said path.
11. The dryer of claim 10 and wherein said heating means comprises a fuel oil-fired burner.
12. The dryer of claim 10 and wherein said heating means comprises a gas-fired burner.
13. The dryer of claim 10 and wherein said heating means comprises a generally cylindrical burner can and means for charging said burner can with a mixture of fuel oil and natural gas.
14. A dryer for carpet and the like comprising a housing defining a carpet inlet opening and a carpet outlet opening, conveying means for moving a single layer of carpet along its length along a path from said inlet opening to said outlet opening through said housing, heating means in said housing beneath said path for directing open flames inwardly from the side edges of the carpet to heat the air in said housing, air circulating means positioned beside said path and arranged to create a zone of relatively low air pressure below the carpet moving along the path and a zone of relatively high vated temperature from one side of the path through the carpet to theothe r side of the path at a first position along the path at a given velocity and then to exhaust the air to the atmosphere or the like and to flow air at substantially the same elevated temperature from the a velocity lower than the said given velocity and to re circulate the air back to the said one side of the path,
and open flame heating means arranged to direct an open flame from the edges of the carpet toward the centerline of the carpet on said other side of the path.