US2123804A - Apparatus for producing cellular concrete - Google Patents

Description

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. COATING 0R PLASTIC; 88

July l2, 1938. J. A. RICE APPARATUS FOR PRODUCING CELLULAR CONCRETE Filed oct'. 18,- 19:55

2 Sheets-Sheet l Examiner I06. COMPOSITIONS,

I Cross Reference COATING OR PLASTIC.

July 12, 1938. J. A. RICE APPARATUS FOR PRODUCING CELLULAR CONCRETE Filed Oct. 18, 1935 2 Sheets-Sheet 2 Patented July 12, 1938 UNITED STATES PATENT OFFICE 2,123,804 APPARATUS FOR PRODUCING CELLULAR CONCRETE Application October 18, 1935, Serial No. 45,684

'4Claims. (01M I)?? If/ The present invention relates to a method of and apparatus for producing cellular concrete and consists in the novel steps of procedure, and

combinations and arrangements of elements of apparatus hereinafter described and particularly set forth in the accompanying claims.

The disclosure herein forms a continuation in part of my co-pending application for U. S. Patent I on Process and apparatus for making acoustic 0 material and foaming compounds, filed April 27, 1931, Serial No. 533,351, and of which parent application there is filed of even date a divisional application for patent on Acoustic material and process of producing the same, Serial No. 45,685,

filed October 18, 1935.

The method phase of the invention consists essentially in combining a cement lurr with a suitable foaming com ound and then aeratin the ixture By mechanically beating oi"'1'fi'c'orporatwag Herein the films of air by means of foraminous or perforated sheets, e. g. screens, that enter the material carrying entrained air which thereafter forms into bubbles that harden and produce a cellular product.

The apparatus is characterized in that it embodies a plurality of arcuate or cylindrical-like sections of screen or perforated material spirally arranged on a common rotatable shaft, which in operation serve to drag films of entrailing air into the mixture of slurry and foaming solution, and simultaneously therewith agitate the mass to thoroughly distribute the created bubbles thus obtaining a uniformally cellular structure.

The invention is shown by way of illustration in the accompanying drawings wherein:

Figure 1 is a vertical sectional view of the machine,

Figure 2 a central sectional view thereof taken on the line 22 of Figure l.

Figure 3, a central sectional view showing a modified form in which quarter spirals are used.

Figure 4, a similar view having one complete spiral.

Figure 5, an embodiment in which only a portion of a spiral is employed, and;

Figure 6, a further embodiment disclosing one continuous spiral of four convolutions.

Referring to the construction in further detail, the apparatus consists of a series of arcuate or cylindrical shaped sections III, II, l2, I3, l4, l5, l6, and I1, formed of screen, w i re cloth expanded or punched sheet metal or other similar material, arranged in spiral like form on the rotary shaft l8, said shaft being journalled on bearings I9 and 20 within a suitably shaped container 2| having discharge outlet 38. There are appreciably wide and open spaces, 22, 23, 24, 25, 26, 21,

28, and 29 between said screen members, and at .30, 3|, 32, 33, 34, 35, 36, and 31 are stops or barriers, also made of the same or similar material as the screen members. The cement and water, with or without aggregate forming a thin slurry, (usually in an auxiliary slurry mixer), are poured into the container 2!, approximately sufficient to fill the same up to the level of the dotted line 10 f.f. Sufficient foam compound is then introduced into the machine, and immediately becomes mixed with the slurry giving the same a foamy character,--that is to say,making it to be of a foamy nature. 15

The screen members, after initially passing through the slurry, will become coated with numerous thin films, and thereafter when the spaces between the turns of the screens are submerged in the slurry, numerous air cells will 20 be formed by the discharge of entrapped air into the slurry through the meshes of the screens. Upon emergence from the slurry, the closed spaces between the screens will again become largely filled with air when the slurry flows out by 35 gravity, and the operation will be repeated during each revolution of the shaft. The spiral principle is believed the most suitable for handling slurries of all kinds such as Portland cement,

clay all thick solutions, and mixtures 30 of liquids and solids in which it is desired to incorporate a cellular structure by means of gas bubbles.

In the modified construction shown in Figure 3 there are four arcuate sections 39 disposed in 35 spiral relation providing spaces 4! between the adjacent ends thereof through which the mixture enters. The screen 42 in Figure 4 is in one piece forming a complete spiral having an opening 43 for the material. In Figure 5 the screen 44 is in 40 one piece arranged spirally for approximately one-third the circumference of the disks 40, and its trailing end is spaced from the edge of disks 40 to provide an entrance opening 45. The screen 46 in Figure 6 is in one piece and of a length 45 to form four complete convolutions having an entrance opening 41 between its leading end and the adjacent convolution.

The function of the barriers or stop members 3| to 31 is to impede the flow of slurry along 50 the spiral channels between the screen members and to form closed spaces when the meshes are filled with films, thus carrying the maximum volume of air deeply into the slurry and giving efficiency to the machine. The use of these stops 55 or barriers increase the output of the machine to an extent appreciably greater than if they were not used. The several sections IO-I'I are assembled in such angular relation that the respective front or advancing edges thereof are uniformally located about the circumference of the tank, and the barriers or bafiies 30-31 are similarly arranged, all to the end of even distribution of load on the machine during working as will be understood. Continued operation of the machine as described will finally use up the available water of the slurry, forming air cells each with a surrounding film of water containing a minute quantity of foaming compound. Thus the aeration will cease when no more water is available, and the slurry will cease to expand in volume as a consequence. If more water is added and the machine operated, the slurry will further increase in volume due to additional films being formed with air entrapped therein.

A suitable mixture is:

When aerated, this mixture will have a volume of approximately six cubic feet, weighing approximately forty-five (45) pounds to the cubic foot. Mixtures of heavier or lighter weight to the cubic foot may be made by correspondingly decreasing .or increasing the amount of water used thus increasing or decreasing the proportion of air cells in the batch. Different kinds of materials may obviously be used e. g. concrete, portland cement, gypsum, clay, or other cementitious subsances, and it is preferred to combine the cement slurry with the foaming compound and then to aerate the mixture as explained.

By varying the character of the compound, the

of the invention except as defined by the claims.

What is claimed as new is:

1. An apparatus of the character described comprising a slurry mixture tank, a shaft journalled therein, a plurality of arcuate members of foraminous material mounted in angularly l5 spaced relation on said shaft, and a plurality of radially disposed foraminous members associated with said arcuate members and cooperable therewith to dip into the slurry mixture and emerge therefrom whereby to cause entrapping of air bubbles therein, as and for the purpose set forth.

2. In an aerating device as in claim 1 foraminous partitions arranged across the spiral-cylindrical members, and dividing the same into a plurality of compartments to increase the air en- 2 the same into a plurality of compartments to increase the air entrapping effect.

-4. An apparatus of the character describg comprising a slurry mixture tank, a shaft bow nailed therein, a plurality of spiral-like members of foraminous material mounted on the shaft in angularly spaced relation, and a plurality of foraminous members radially intersecting said arcuate foraminous members and cooperable therewith to dip into the slurry mixture and emerge therefrom whereby to cause entrapping of a) JOHN A. RICE.

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