US3462851A - Web treating apparatus - Google Patents

Description

J. c. URBAS ETAL WEB TREATING APPARATUS 2 m m a e m m VII 8 m g T m? A 0% 1m NT L H A ww 7 9 1 9 m 5 e D d e n F I!!! WWI!!! United States Patent Ofiice 3,462,851 Patented Aug. 26, 1969 US. Cl. 34-160 2 Claims ABSTRACT OF THE DISCLOSURE A web-wide air distributing nozzle is provided with a segmented valve element designed to occlude about half the nozzle opening for more eflicient application of air volumes at improved heat transfer rates.

This invention relates to an apparatus for the treatment of materials that previously had been subjected to a processing step requiring a setting of the step applied, or drying of a coating, or an inking application or heating of a material which has not been subjected to a processing step.

Setting or drying or heating an applied treatment on a traveling material is generally done by heated gases, usually air. Such gas is applied directly generally perpendicularly or at such an angle to the treated surface and in volume suflicient to effectively perform the desired function. Oftentimes more air than necessary is used to effectively treat a web. This is inefiicient and expensive since heat is wasted and air moving equipment of larger than needed size is utilized.

Advantageously, the present invention provides for a flexible and eflicient hot air distributing nozzle, a longitudinally extending jet, forming part of a material treating apparatus adapted to control air application in volume at improved heat transfer/HP rates for web treatments for over a range of requirements. This economic utilization of heated air is had through the control of the area of a narrow opening forming the nozzle outlet, the air emitting area by an inner space occluding means.

It has been discovered that a nozzle of equal outlet area but where the area is divided by means of alternating occluding elements will yield a higher rate of heat transfer/HP than if the nozzle were one complete area or opening with no occlusions and irrespective of length. This, of course, does not means a decrease in nozzle length since a full length is required to spread a heating fluid over a full width of the material treated but about half of the nozzle opening is occupied by a spaced valving means.

Such spaced valving of each transverse nozzle of a plurality comprising a longitudinally extending treatment system can be coordinated for over the treating area to emit only suflicient air as required for a treatment. When properly disposed the many jets formed through such combination impinge on traveling web surfaces giving excellent rates of heat transfer. The cross-section of the nozzle may be rectangular or it may be V-shaped or it may be a slit that is open its entire transverse length. The valving can vary in segmental length according to flow and spread required, however, it must conform to the nozzle opening so as to be positioned therein to desirably diminish the spaced gas outlet area to required flows. The distance or space between the valving in a nozzle provides for an improved heat transfer/HP treatment.

It has been found that properly disposed nozzles with valved emitting jets of gas designed to directly cover a passing web area with minimum overlap obtain an efficient and an improved heat transfer/ HP.

Referring now to the following specification and accompanying drawing, where:

FIGURE 1 is an elevation representative of a totally enclosed apparatus for the treatment of moving material by direct impingement of gas or air under pressure;

FIGURE 2 is a sectional detail of the air plenum, outlet nozzle and occluding valving therein taken across line 22 of FIGURE 1;

FIGURE 3 is a fragmentary perspective detail of the valving employed in association with the nozzles of FIG- URE 2 taken across line 3--3 thereof;

FIGURE 4 is a further detail of the nozzle occluding valving structure similar to FIGURE 2 but shown in an alternate position;

FIGURE 5 is a detail similar to FIGURE 3 taken along line 55 of FIGURE 4 showing the space occluding valving in a different position; and

FIGURE 6 is a view similar to FIGURE 5 but showing a modification.

It is imperative in competing industries that production time and its cost be maintained at most economical levels. In the paper industry one area being under continued improvement is that of setting or drying, or cooling of a previously treated web; this being done at substantial production speeds. Generally, as pictured in FIGURE 1, such an apparatus comprises an outer enclosure 20 containing an inner plenum chamber 21, the area between the two being an exhaust area with end exhausts 32. An inlet 22 for air or gas under pressure to the plenum 21 is provided at about midpoint. The air from the plenum flows outwardly through a plurality of nozzles 23, each of a similar structure, onto a passing treated web 10, impinging thereon at a predetermined pressure and spread.

The supply and takeup of the web 10 are not shown as such arrangements are generally known, only its travel through liquid applying zones and air treatment apparatus. A web material 10, as an example, is led over a guide roll 11 onto and over an initial coating or printing applying roll 12 which is partly positioned in a liquid bath 13 being applied to the web then under another guide and tension roll 14 to a second coating or print applying roll 15 partly positioned in a bath 16 and over roll 17 to and through an opening 18 of enclosure 20; then the web passes over a series of guiding and supporting rolls 25 out through an exit 19 over support rolls 26, 27, 28 and onto a collecting mandrel (not shown). The length of web 10 generally between entry 18 and exit 19 is subjected to a drying or set-up treatment effected by the impingement of hot or cold air coming from the facing nozzle openings 23. Air under pressure coming in through the inlet 22 is forced out through the openings 23 at a predetermined regulated rate to impinge on, in an expanding covering manner, the face of the treated moving material 10, then it flows out from the space about the plenum 21 through exits 32, for cleaning and recirculation.

As shown in greater detail in FIGURES 2 and 3 the nozzle portion 36 of the plenum 21, and its space occluding valving 37 comprises, as an example, a transverse V- shaped structure having sides 36 tapering to a nozzle opening 39. Placed in the V-portion and adapted to be placed in the opening is a segmented square-toothed space occluding valve 37 extending the width of the nozzle 36. The open section 39 between the spaced valve segments 37 is open into the plenum permitting a continuous flow of drying or heated air or gas, the valving segments 37 alternately occluding the nozzle spacing yet improving the heat transfer/HP and drying without any additional but minimized quantities of treating air.

A fully closed position of the valving 37 is shown in FIGURE 3. When the segmented valve 37 is dropped entirely into the outlet of the nozzle 36, air in that area is shut off and the only air is that flowing through the intervening open sections 39 to act on the passing material 10. This valving position provides for less than about half of the total air that otherwise would be required, however, resulting in an improved heat transfer/ HP rate. FIGURES 4 and 5 further show in greater detail the flexibility to divisiveness of the nozzle opening by the valving 37. The lengths of the segments 37 forming the valve can readily be determined to give diflerent total air flows at improved heat transfer/HP rates.

Depending on the size of the treating apparatus the occluding valve 37 sections can be either manually or mechanically moved into or out of position. Where weight and size are factors a simple, actuating movement and support means are shown in FIGURES 3, 5 and 6. The valve can be formed from an angular element its depending leg alternately cut out to form the valving and its upper right-angular section 38 used for attachment to a dog-leg element 41 of member 40 through a securing means 42. The vertical member 40 can be attached through suitable linkage 44 to a reversing motor 50. The valving members also can take the form of a triangle as shown in FIGURE 6 for total occlusion of its section of the nozzle length, and as described leaving intermediate areas 54 open to the plenum.

EXAMPLE I As an example, a comparison of test runs of nozzle openings of continuously open length as against another that was about half occluded by means of space blocking valving gave the following results:

It is to be noted that for the same slot size width but for about half the length blocked by valving and with much less volume, the improvement in heat transfer/ HP is decidedly increased.

A further advantage of the valving occurs when nozzle plugging with lint, etc., from cellulosic material or staple 4 fiber blankets is expected to hamper production. This problem is overcome by constructing a nozzle opening which is twice as large but is half closed by valving means. This provides for a larger opening with less chance of plugging but still using the same air volume with the same or a slightly increased heat transfer/HP rate.

What is claimed is:

1. A web treating apparatus comprising, an enclosed chamber with an entry and an exit for a web to be processed moving therethrough, a plenum in said chamber, a plurality of spaced nozzles in series and positioned transversely to a web traveling therethrough forming the lower face of said plenum and communicating therewith, and each of said nozzles having alternately closed and open sections through its length, the spacing of the closed and open sections being about equal.

2. In a web treating apparatus of the character described in claim 1 wherein each nozzle comprises a plurality of open and of closed sections and where each starts and ends with a closed section.

References Cited UNITED STATES PATENTS 2,557,838 6/1951 Phister 239506 2,666,994 1/1954 Dungler 34160 XR 3,161,482 12/1964 Gschwind et al. 34155 XR FOREIGN PATENTS 812,429 4/1959 Great Britain. 1,054,251 10/1953 France.

FREDERICK L. MATTESON, IR., Primary Examiner H. B. RAMEY, Assistant Examiner US. Cl. X.R. 239-568

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