US2201212A - Dissolver - Google Patents

Description

v May 21, 1940;

"K. s VALENTINE DISSOLVER Filed March 116.. 1938 2 Sheets-Sheet l I 4 7w i May 21, 1940; K. s. VALENTINE DISSOLVER Filed March 16, 1938 2 Sheets-Sheet 2 New MW M WW W Patented May 21, 1940 UNITED STATES DISSOLVER Kenneth S. Valentine, New York, N. Y., assignor to The Patterson Foundry & Machine 00., East Liverpool, Ohio, a corporation of Ohio Application March 16, 1938, Serial No. 196,295

1 Claim.

My invention relates to an improvement in dissolvers.

The object is to provide a dissolver used in cutting cotton, or in other words for dissolving nitro-oellulose as used in film solution, artificial leather, pyroxylin lacquer, etc., the general characteristics of all of these solutions being the same, since the resultant product is liquid rather than plastic, although the liquid may vary greatly in viscosity.

This dissolver may be used also for dissolving natural and synthetic resins, gums, etc., also for certain types of dispersion.

Heretoforathe equipment generally in use has not operated eificiently on varying viscosities, for the reason that dissolving of nitro-cellulose, natural and artificial resins, gums, etc., the solutions vary from less than 1000 all the way to more than 2,000,000 centipoises in viscosity, and consequently it has been necessary in the past to.

use one type of machine for low viscosities, and an entirely different machine for high viscosities, with machines of still different design for intermediate visco'sities.

The usual type of cotton dissolver now in use consists of a rather fiat container with a turbine located in the bottom, with a stationary deflecting ring provided to promote shear and break up the tendency to swirl. In such a machine, half second cotton can be dissolved to final viscosity of 30,000 centipoises in thirty to forty minutes. On the other hand, two and one-half hours are sometimes required to make a film solution of the same viscosity. Fifty per cent more time is required to dissolve nitro-cellulose from wood pulp than is required for dissolving the same product made from cotton linters. For very high viscosity, the deflecting ring is generally omitted, as there is no tendency to swirl with the heavier material.

In the present invention, it is possible to handle the entire range from less than 1,000 to more than 2,000,000 centipoises on the most economical basis, and in the design of the present machine it will be seen that I have followed the general principle of relatively large diameter with low height, but the following additional novel features have been provided, which features taken together account for the difference between the present invention and the present day conventional dissolver, and for the advantageous results attained by these improvements:

First, my invention comprises adjustable baffles which may be instantly changed so that they either fold clear back against the wall of the tank with a maximum projection of approximately one-half inch, or they be immediately turned so that they project at right-angles with the wall of the tank, thus providing the optimum amount of shear or mixing action where materials are to be dissolved to a final viscosity of 30,000 centipoises or less, or, when the baffles are turned back fiat against the wall of the tank, products with a final viscosity of from 1,000,000 centipoises to over 2,000,000 can be handled with the greatest expediency, materials in the intermediate range between 30,000 and 1,000,000 centipoises being most expeditiously dissolved by adjusting the bafiies to the proper angle anywhere between the above recited extremes to obtain the desired and most efiicient dissolving action.

From the foregoing, it will be seen that one of the objects is to attain great flexibility by the proper use of the adjustable baffles which provide a maximum efficiency at various viscosities.

By the use of this machine, the dissolving time is reduced to approximately one-tenth of that ordinarily required for dissolving, cutting and. similar operations, consuming much less horsepower both on account of the reduction in time, and due to the efficient design of the machine itself.

In the accompanying drawings:

Fig. l is a view in elevation partly in vertical section; lig. 2 is a plan view on the line 22 of Fig. 1; an

Fig. 3 is an enlarged fragmentary vertical sec tion through one side of the tank, showing one' of the adjustable baffles in elevation.

A, represents the machine as a whole, and I, is the tank. This is preferably of relatively large diameter and of shallow depth, although, obviously, these proportions might be changed. For instance, a tall tank, with two turbines, one above the other, might be used.

A turbine 2 is keyed to the lower end of the rotary shaft 3, and the shaft is driven by the uni-power drive 4 located above the tank. The blades of the turbine 2 are curved as shown in Fig. 2, and preferably turned to difierent planes at their tips as fully set forth in an accompanying application filed herewith.

Baflles 5, are pivotally mounted at intervals alongside the side wall of the tank, and each is provided with a handle 6 at the upper end, whereby the bailles may be turned to suit the requirements, from outside the machine.

These adjustable bafiles are employed to satisfactorily handle materials of various viscosities. When high viscosities are handled, the bafiles are turned close to the shell of the mixer that is out of use, but they are adapted to be turned into the vats at increasing angles as viscosity decreases, or when less viscous materials are handled and when required at various intermediate points.

This open, curved blade type of turbine either with or without a stator, depending upon the material being dissolved, as Well as the use of a tank with a dished bottom 9, is preferred and hence illustrated, but these features are not necessarily essential to the present invention which resides largely in the use of the adjustable baflles. They afford a means of regulating the degree of rotating action of the material being handled. By their use, swirl is prevented and thus a batch of either thin or viscous materialv may be handled in this same machine with equal efiiciency.

the bafiles.

A man-hole I is formed in the top of the tank, and a discharge outlet 8 at the bottom.

I claim:

The combination of a tank having a cylindrical intermediate portion, a rotatable shaft located in the tank, an impeller carried by the shaft and having blades, each blade having a portion in a vertical plane and being inclined toward its tip, baffles pivotally supported in the ends of the tank, with one edge contiguous to the cylindrical wall and extending substantially throughout the height of the latter, whereby all material within the tank forced against and following the wall of the tank, is deflected by the baffles when they are turned outwardly, thereby retarding and turning back the material in the direction of the impeller, and means outside of the tank for regulating the axial position of KENNETH S. VALENTINE.

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