US2255859A - Method of cleaning and drying strip or sheets - Google Patents

Description

Sept. 16, 1941. w. M. QUIGLEY METHOD OF CLEANING AND DRYING S''RIP OR SHEETS Filed April 2s', 1939 FIEL! M-EHaTaEEL/ELIB.

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.ffii/dry@ Patented Sept. 16,1941

l METHOD F CLEANING AND DBYING STRIP 0B SHEETS Winfred M. Quigley, West View, Pa., assignor to Carnegie-Illinois Steel Corporation, a corporation of New Jersey appiicauonapru 2s, 1939, serial Nn. 210.691;

(ci. is-zss) 1 Claim.

The present invention relates to a method of cleaning and drying strip or sheets, and particularly those which are made of metal.

Heretofore, it has been'the general practice to rinse foreign matter from the surface of metallic strip or sheets by means of water immersion or sprays, which step was followed by removing the excess water by squeegee rolls or wipers andthe material then dried in one of several manners, for example, by means of the blast of hot air or by passing the material through a drying oven. The water available for said rinsing purpose generally contains in solution therein small amounts of salts, for example, carbonates etc., either present from natural sources or added'in softening treatments of the same. During the drying step, such materials remain on the surface of the strip material and result in a stained appearance which, in a great many cases, is objectionable in a finished product.

An object of the present invention is to subject the surface of strip or sheets, and particularly those4 which are made of metal, to the action of a hot vapor for removing any foreign matter therefrom, and imparting such surface characteristics that they'will immediately produce a dry surface free from drying stains.

Another object of the present invention relates -to removing from the surface of strip or sheets any substance such as water containing dissolved salts and/or any traces of residual matter resulting from previous processing steps.

Still another object of the present invention is to subject the strip or sheets to successive stages of steam treatment to remove the foreign matter from the surfaces thereof, and at the same time gradually heat the same so that upon exposure to the atmosphere, any remaining moisture is immediately evaporated.

Other objects and advantageswill become apparent as the description proceeds and reference is had to the accompanying drawing, in which:

Figure 1 is a sectional elevation of a form of apparatus which may be used to practice the method of the present invention; and,

Figure 2 is a sectional view on the line lI-II of Figure 1.

The continuous strip or lsheet being treated under the present invention may be fed from a brushing and scrubbing device (not shown) and enters the present apparatus for treatment by passage between rubber coated pinch rolls 2 positioned at the entrance end of the apparatus.

The improved drying apparatus of the present invention comprises a hood-like structure I, within which are positioned a plurality of feeder pipes I arranged transversely of the travel of the material through the apparatus so as to direct steam on both surfaces of the strip material. These pipes are each provided with a plurality of nozzles or openings 5, whereby steam is ejected onto both surfaces of the material at such an angle as to impinge upon the surface of the material countercurrent to the passage of the strip material. This maintains a desired sweeping action on the surface of said material so as to remove the condensate resulting from the action of the steam ejected from the preceding pipes. f

From the nozzles or openings of each pipe, steam which is ejected against the surface of the strip or sheet in the most effective manner conso that upon emerging from the apparatus, it

contains suiilcient heat to immediately evaporate lthe final film of vmoisture remaining on its surface.

Referring more particularly to Figure 2, it will be perceived that the pipes 4 which are adjacent the entry end of the hood-like structure are supplied with wet steam through a leader 6 to proy vide maximum condensation and washing effect on the surface of the material, while those pipes 4 which are adjacent the exit side of the hoodlike structure may be supplied with dry steam through a leader 6a to provide maximum heating and drying effect upon the strip or sheet. 'I'his arrangement of a two-*stage effect provides a maximum rinsing effect of the material adjacent the entry side of the hood structure and a maximum drying action to the material as it exits from said hood structure, thus minimizing the amount of moisture carried out of the hood structure on the surface of the material.

To take care o f the condensed steam which may gather within the hood structure, an inclined catch basin 1 is provided beneath the lower feed pipes I. Any conventional type of construction may be provided for catching and withdrawing the condensate.

At the exit end of the hood. there are provided rubber covered pinch rolls l which serve the purpose of substantially' removing any 4moisture n, 2 einem l` which may remain on the material after passing the la'st set of nozzles.

While I have shown and vdescribed a certain speciic embodiment of the present invention, it will beseen that Ido not wish-tube limited exactly thereto, since various modifications may be made without departing from the scope of the invention, as dened by the following claim.

The methodY of cleaning and drying strip ma- 10 `mm1 or sheets which inclus 'owing the same between a pair of squeegee rolls, applying to the surface 'thereof a'lm of low pressure wet steam v directed at an angle which is lcounter.,urx'enia to its direction of movement. subsequently applying to thestrip or sheet a film or high pressure steam at an'angle which is counter-current to its movement, and then passing the stripor sheet between a; second pair of Squeegee 1'0118- l WINFRED M.v QUIGLEY.

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