US1735506A - Carbonaceous briquette and process of making the same - Google Patents

Description

" in Drawing.

Patented Nov. 12, 1929 UNITED STATES PATENT- OFFICE HUGH F. RIIPPEY, GLENN DAVIDSON, CHARLES N. CONE, IRVING F. LAUGKS, AND HARRY P. BANKS, OF SEATTLE, WASHINGTON GABIBONACEOUS BRIQUETTE AND PROCESS OF MAKZ IING THE SAME place, since it is used in great quantities,-

it must be relatively cheap. Second, it must have suflicient adhesion to the particles of carbonaceous material to produce a briquette strong enough to withstand the shocks incident to handling to which such briquettes are commonly subject. Third, it must have sufficient resistance to water, so that when briquettes are stored in the weather, they will not disintegrate. Fourth, it must hold the particles together in the fire so that the briquette burns as a Whole or as a lump, and does not fall to pieces prior to its burning as a result of the application of heat. Again, the ash content of the briquette must be practically the same as that of the carbonaceous material from which it is made. The binder material should be as nearly smokeless as the particular carbonaceous material to be briquetted. For instance, a binder for charcoal must not increase the volume of smoke given oil? from burning charcoalwithout a binder.

And, finally, the briquette must be odorless.

Manifestly, any objectionable odor in the burning of the briquette would render the br quette practically useless as a fuel. A primary object of our invention is to provide a briquette of carbonaceous materlal having a binder which satisfies'each and all of these requirements.

We have found a suitable base for the bind-' er of a briquette of carbonaceous material 40 is soya bean flour. -Wherever the term soya bean flour is used herein, it is used to include soya bean ground to a flour as a whole, and also the extracted soya bean protein which is then ground to a flour-like condition. That is, the term soya bean flour as herein used includes the extracted soya bean protein, and the protein in conjunction with the other parts of the soya bean. Soya bean flour has the first requisite, namely, cheapness. It also has an inherent resistance to water which is Application filed May 3, 1926. Serial No. 106,550.

probably due fundamentally to the nature of the soya bean protein. Soya bean binders, however, are particularly characterized by having a strong adhesion to particles of carbonaceous material, which renders them particularly suitable for a binder of such material.

We obtain soya bean flour by grinding the cake after the oil has been extracted. Oil is extracted from soya beans, in general, by subjecting the crushed and more or less cooked beans to hydraulic pressure, whereupon the oil is squeezed out and the cake results. This cake is then dried and is a common article of commerce. The cake is ground to a fineness such that all of its particles ordinarily pass an eighty-mesh screen. We do not, however, Wish to limit ourselves to this particular fineness, as it may be ground coarser or finer as the particular purpose may require. In general, however, the finer the particles, the more readily they will mix with water and other agents to form an adhesive mixture.

Water alone, when mixed with soya bean flour, has a certain dispersing tendency. That is, it swells the particles, softens them, and when subjected to mechanical action they become much finer; in fact, their size falls within the limits of the colloidal state of matter, and this action is ordinarily termed dispersing. We use the word dispersing as being the accepted term among colloid chemists to denominate the efiect produced, although we do not wish to bind ourselves to any particular interpretation of the word. The efiect produced is a transformation of a mealy mass when wet to a more or less smooth mass. It is generally believed that this change is due to a change in the size of the particles.

We find, however, that other chemicals added to soya bean flour, promote the dispersion, and, in general, increase its value as an adhesive agent. Such compounds are quite various in their nature. Salts of weak acids and strong bases, for example, sodium sulphite, sodium phosphate, sodium borate and the like, have a certain dispersing action. For the present purpose, however, the most convenient and cheapest agent to use is caustic soda. This maybe added as such, or, if desired, a sodium salt of an acid which forms an insoluble lime salt, together with calcium hydrate, are mixed dry. When this mixture is wet, caustic soda results by interaction. In

I making briquettes of carbonaceous material,

however, this method of producing caustic soda has the disadvantage of raising the ash content.

It is preferable then, from all stan-dpoints, to use as a dispersing agent caustic soda, although we claim as equivalent in this connection any compound or chemical which has a dispersing'actionon soya bean flour.

The method of use will be clear'from the following examples: Our experiments have included coal, coke, coke fines, charcoal and sawdust, and the term carbonaceous material is therefore used herein to cover all such types of fuel. I

One part of soya bean flour is put in a mechanical mixer with two parts of water and stirred until wet. One-tenth part of caustic soda dissolved in water is then added while stirring. This mixture thickens and is stirred thick for five or ten minutes. Then sufiicient water is added to make five parts of water, total. This wet mixture constitutes the hinder. It is then mixed with one hundred parts of the carbonaceous material which it is desired to briquette. This mixing must be thorough andmay be effected by any of the various well-known mechanical mixers which are designed to mix coal with binding agents. The mixture is thenput under pressure which may be anywhere from one thousand to fifteen thousand pounds per square inch and pressed into form. I

We have found that a. considerable improvement is effected in the strength and water resisting properties by subjecting the finished briquettes, after they come out of the molds, to a drying process. The temperature of this drying process does not need to be high, as a heat of less than two hundred departs of water, at about one hundred degrees grees Fahrenheit is suflicient. If the .briquette 1s slmply allowed to air-dry at normal temperature, it' does not make as water resistant Fahrenheit, in the mixer used for the binder and add to this, while stirring, one part of soya bean flour and stir to a smooth paste.

Then add one-tenth part caustic soda, dis-- solved in one-half part of water, and stir five .mlnutes in the heavy stage. Then add one part of mel ed asphalt and-stir well together. Then add slowly eight and one-halfparts cold water. This gives the finished binder.

. From thispoint on, the process is the same as described above.

In ,the first example, morelwater may be added. This depends a good deal on the. character of the carbonaceous material, the

size of the particles which it is desired to briquette, and the amount of moisture present in the carbonaceous material itself. We find that the minimum amount of the' finished binder, including the water, is eight or nine per cent of the weight of the material briquetted. Y

We have also used other formulae for the binder, for example:.

800 parts soya bean flour 120 parts lime 180 parts rosin I I 16 parts permanganate potash 60 parts sodium fluoride 80 parts sodium carbonate 16 parts copper sulphate with 3900 parts water.

This provides a good briquette when mixed with coal in the amount of about ten percent of the wet mixture on the weight of the coal.

Another mixture is:

300 parts soya bean flour 12 parts caustic soda I 7.5 parts permanganate potash 1 part hydrated lime with about 1500 pounds of water.

Briquettes made by the last two formulae have good properties, but are more expensive to make. I

Another example of a class of formulae successfully used in briquetting carbonaceous material, particularly charcoal for instance, is:

, 5 parts soya bean flour 10 parts low grade wheat flour 5 parts molasses (low grade) I 3 parts hydrated lime 4 parts sodium carbona 100 parts water. I

Our invention is not to be limited to the specific examples given above, which are merely illustrative of several ways of using soya bean flour to efl'ect the binding or briquetting of carbonaceous material.-

.We claim I 1. As a new article of manufacture, a briquette composed of carbonaceous material,

which is held together by a binder, which binder embodies soya bean flour dispersed with caustic soda.

2. As a new article of manufacture, a briquette composed of carbonaceous material,

which is held together by a binder, the base of which is soya bean flour. 3. As a new article of manufacture, a bri-' quette composed of carbonaceous material, which is held together by a binder embodying soya bean flour dispersed and mixed with asphalt.

4. The process of making a briquette of carbonaceous material of mixing one part of soya bean flour with'two parts of water;

stirring the same until wet; adding one-tenth part caustic soda dissolved in water during said stirring; stirring the thickened mixture for from five to ten minutes; adding sufiicient parts of water to make five parts of water altogether; thoroughly mixing the binder thus prepared with one hundred parts of carbonaceous material molding the mixture into desired forms; removing the molds; and subjecting the briquettes to a drying temperature of one hundred to two hundred degrees Fahrenheit.

5. As a new article of manufacture, a briquette composed of carbonaceous material, which is held together by a binder embodying soya bean flour, low grade wheat flour,

- molasses (low grade) hydrated lime, sodium carbonate. and .water.

6. As a new article of manufacture, a briquette composed of carbonaceous material, which is held together by a binder embodying five parts soya bean flour, ten parts low grade wheat flour, five parts molasses (low grade),

three parts hydrated lime, four parts sodium carbonate, and one hundred parts water.

In witness whereof, we hereunto subscribe our names this 24th day of April, 1926.

HUGH F. RIPPEY. GLENN DAVIDSON. CHARLES N. CONE. IRVING F. LAUCKS. HARRY P. BANKS.