US2362309A

US2362309A - Moistening apparatus

Info

Publication number: US2362309A
Application number: US472176A
Authority: US
Inventors: John O Ross
Original assignee: J O ROSS ENGINEERING CORP
Current assignee: J O ROSS ENGINEERING Corp
Priority date: 1943-01-12
Filing date: 1943-01-12
Publication date: 1944-11-07
Anticipated expiration: 1961-11-07

Description

Nov. 7, 1944. J. 0. R088 MOISTENING APPARATUS Filed Jan. 12, 1943 INVENTOR I AT ORNEY Patented Nov. 7, 1944 UNITED STATES PATENT OFFICE MOISTENING APPARATUS John 0. Ross, New York, N. Y., assignor to J. 0. Ross Engineering Corporation, New York, N. Y., a corporation of New York Application January 12, 1943, Serial No. 472,176

4 Claims.

This invention relates to increasing the moisture content oi water-absorbent material. A specific embodiment of the invention pertains increasing the water content of a strip of fabric of low tensile strength.

An object of this invention is an apparatus for providing a low tensile strip of water-absorbent material with a predetermined moisture content uniformly distributed throughout the material in the shortest possible time and while the material is kept free from tension.

According to this invention, moisture is added to the strip by continuously feeding it into and out of a chamber in which it is contacted with hot humid air and maintaining the stripbefore and after passage through said chamber at a temperature below the temperature of the contacting air. For example, by impinging the strip with a conditioned air stream of 95 F. temperature and 90% relative humidity, the strip being of approximately 75 F. temperature, a surface deposit is formed on the strip in the matter of a very few seconds and the temperature of the strip is brought up very close to the dew point temperature of the air. From then on, moisture can be absorbed into the strip only by the slow process of approaching equilibrium. The moisture provided by the surface deposit usually is less than is required to give the strip the desired moisture content. Therefore, to supply the desired moisture content to the strip, the strip, after being subjected to the treatment above described, is cooled to approximately its original temperature under conditions such as to prevent appreciable evaporation of the deposited moisture and then the above-described treatment with hot humid air is repeated. Preferably, the strip is. cooled by impinging with cold air of high humidity b t may be cooled by other suitable means. The strip is subjected to repeated cycles of the treatment above described until it reaches the desired moisture content. Each treatment of the cooled strip with hot humid air is eflected in a short period while each cooling operation likewise requ res only a short period so that in the matter of a few seconds the strip is brought to the des red moisture content as only a relatively few passe"- of the strip through the hot humid air is required to provide it with the desired moisture content. In order to support the strip free from tensi n during the moistening operation, a succession of conveyors is provided for supporting the strip during its subjection successively to the hot hum d atmosphere and cooling it between such treatany tensile strain during the addition of moisture I thereto.

Other objects, novel features and advantages of this invention will become apparent from the following specification and accompanying drawing, wherein the single figure of drawing illustrates schematically one form of apparatus for treating strip material according to the invention.

The treating chamber I0 is divided into a cooling compartment II and a moistening compartment l2. In each compartment are provided several rolls l3 on which are supported conveyors H, each of which is arranged partly in compartment H and partly in compartment l2. The partition l5 which divides the chamber I 0 into the compartments II and I2 is provided with apertures it through which the conveyors pass. Drive means I l. are provided for rotating the rollers I 3 to cause feeding of the conveyors M.

In the cooling chamber l l is provided a plurality of ducts l8 each overlying the top reach of one conveyor. In the moistening chamber 12 is provided a plurality of ducts l 9 each arranged above the upper reach of a conveyor. Both the ducts l8 and iii are supplied with a large number of relatively small apertures through which air may be discharged toward the underlying conveyor. A supply duct 20 is provided for delivering cold humid air to the ducts l8 and a suppl duct 2| is provided for delivering hot humid air to the ducts l9.

of the top conveyor and is advanced successively by the top conveyor and the remaining conveyors alternately through the compartments II and I2 and is finally discharged from the bottom conveyor through the aperture 26 in the wall of compartment i I. The strip S thus passes at a predetermined rate back and forth in several reaches through the two compartments and after its last passage through the cooling compartment is discharged from the treating apparatus to suitable take-up mechanism, not shown. From the duct 20 cold moist air 01' a predetermined temperature is supplied to the ducts i8 and through the duct 2| heated air of predetermined air and moisture content is supplied to the ducts IS. The air thus supplied is caused to impinge on both sides of the strip as it travels through the apparatus.

In normal operation of the apparatus, the strip S is first brought to a predetermined temperature in the compartment H, for example, 75 F. and then is carried into the compartment 12 where it is subjected to air preferably of 95 F. and 90% relative humidity. The strip is then returned to the cooling chamber where its temperature is reduced and the cycle above described is repeated a predetermined number of times.

During its various passes through the moistening chamber, a surface film of moisture is deposited on the strip due to the fact that its temperature is below the dew point temperature of the air supplied to the ducts l9 and the temperature of the strip is brought up very close to the dew point temperature of the air. After the temperature of the strip has nearly reached the dew point temperature of the air no further moisture will be deposited on the strip except by the slow process of approaching equilibrium. The deposit of the surface film and the elevation of the strip temperature to nearly the dew point temperature of the air takes place in a matter of a few seconds and the strip speed and the length of its path in the compartment I2 is so determined that it remains in the compartment only long enough for such effects to be accomplished. The strip absorbs the deposited moisture and is then returned to the compartment II for cooling and appreciable evaporation of moisture from the strip is prevented by the humid condition of the cooling air. Through successive treatments, the strip absorbs enough increments of moisture to provide it with the desired moisture content in comparatively short time as the alternate passages of the strip through the cooling chamber 2. Apparatus for moistening a continuously moving strip oi water-absorbent material comprising a horizontally elongated housing divided by a vertical wall into a pair of chambers, a plurality of superposed conveyors each common to both chambers and passing through restricted openings in said vertical wall, a first and a second opening in vertically spaced planes in an outer side wall of one of said chambers, the first of said openings being provided for the passage of said strip from the exterior of said housing to the first of said conveyors and the second of said openings being provided for withdrawing it from the last of said conveyors to the exterior of said housing, means for driving successive conveyors in opposit directions, the delivery end of each conveyor except the last one being so positioned as to discharge said strip to the next conveyor, ducts in each chamber arranged above the conveyors, each of said ducts having apertures adapted to direct air toward said strip on the underlying conveyor, means for supplying cold humid air to the ducts in one chamber, and means for supplying hot humid air to the ducts in the remaining chamber.

3. Apparatus for moistening a continuously moving strip of water-absorbent material comprising a horizontally elongated housing divided by a vertical wall into a pair of chambers, a plurality of superposed conveyors each common to both chambers and passing through restricted openings in said vertical wall, a pair of openings in vertically spaced planes in an outer side wall of one of said chambers, the upper of said openings being provided for the passage of said strip from the exterior of said housing to the upper of said conveyors and the lower of said openings being provided for withdrawing it from the lower of said conveyors to the exterior of said housing, means for driving successive conveyors in opposite directions, the delivery end of each conveyor onds each.

It is of course understood that various modifications may be made in the apparatus and procedure above described without in any way departing from the spirit of the invention as defined in the appended claims.

I claim:

1. Apparatus for moistening a continuously moving strip of water-absorbent material comprising a horizontally elongated housing divided by a vertical wall into a pair of chambers, a plurality of superposed conveyors each common to both chambers and passing through restricted openings in said vertical wall, a first and a second opening in vertically spaced planes in an outer side wall of one of said chambers, the first of said openings being provided for the passage of said strip from the exterior of said housing to the first of said conveyors and the second of said openings being provided for withdrawing it from the last of said conveyors to the exterior of said housing, means for driving successive conveyors in opposite directions, the delivery end of each conveyor except the last one being so positioned as to discharge said strip to the next conveyor, means for supplyingcold humid air to said strip in one chamber and means for supplying hot humid air to said strip in the remaining chamber.

except the lower one being so positioned as to discharge said strip to the next lower conveyor, means for supplying cold humid air to said strip in one chamber, and means for supplying hot humid air to said strip in the remaining chamher.

4. Apparatus for moistening a continuously moving strip of water-absorbent material comprising a horizontally elongated housing divided by a vertical wall into a pair of chambers, a plurality of superposed conveyors each common to both chambers and passing through restricted openings in said vertical wall, a pair of openings in vertically spaced planes in an outer side wall of one of said chambers, the upper of said openings being provided for the passage of said strip from the exterior of said housing to th upper of said conveyors and the lower of said openings being provided for withdrawing it fromthe lower of said conveyors to the exterior of said housing, means for driving successive conveyors in opposite directions, the delivery end of each conveyor except the lower one being so positioned as to discharge said strip to the next lower conveyor, ducts in each chamber arranged above the conveyors, each of said ducts having apertures adapted to direct air towards said strip on the underlying conveyor, means for supplying cold humid air to the ducts in one chamber, and means for supplying hot humid air to the ducts in the remaining chamber.

JOHN O. ROSS.