US2217994A - Fuel briquette and method of making same - Google Patents

Description

Patented 15, 1940 I a V I N E A ES ATENT] a FUE-LBRYIQUEST;

Gregor'yG; Rick, Merriam, and-Charles E. Loetel, Kansas City, Kans., assignorsto Anderson- StolzCorporation, a corporation otMissouri No Drawing. Application November 18, 1938,

g r Serial No. 241,138

I Claims; (01. 44-46) This invention relates to powdered fuel britractor-solution has a pH in theorder of about quettes and'to methods-of making the same and, 12, 2 in particular, to a novelbinder for bonding pow- W I t'appears that there is a relationship between dered fuel into briquettes I a the'alkalinity of theextract'orsolutionand its 5 Powdered fuel briquettesas heretofore made rate of setting'when used ass; binder forpow- 5 have notbeen entirely satisfactorydue to theirdered'fuel. As the alkalinity of the extractor, so tendency towards formation of fiyash and dust: lution' isincreased, its rate of oxidation likewise I h ing and the inability of the briquette tohold to- "in creases and it's" time of setting is, accelerated. gether during burning. These objectionable feawe haveffoundthat thepresen'ce ofvalkalizin a tures are attributable to the binders heretofore quebracho extractor solution thereof incre'ases 10 a employed for bonding the powdered fuelinto bri its adhesiveness and makes possible the producquettes. We have noted that many-of the known tion of powdered fuel briquettes; at normal tem+f binders used in making briquettes are also obperatures, of sufficient hardness and rigidity'to be jectionable because of theirtendencyto carbonize self-sustaining at the time of*removal from the i5 and hinder the burning of the briquettes and bebriquette machine. The binder sets inair: in cause-of their inability to set or bind together about 2 to'about'l hours,"at normaltemperatures, the powdered fuel particles with sufficient rapidthereby di p th e of t yy ity to make their use practicable. ovens. i i p I In accordance with our invention the above and The quantity of quebracho extract (on a dry other disadvantages in fuel briquettes andin the b s s sufiici nt to b nd t e p r es f powdered "2o methods of making the same have been overcome fuel into a briqu may ry a e d as j by our use of a novel binder for the powdered desired, although for most purposes, from about fuel. The binder for the powderedfuel used in 2% to about 10% by Wei o quebracho extract accordance with our invention is a water-soluble in re pe t of the We g t of the powdered fuel will tannin-containingextract known as quebracho accomplish the desired result. Larger amounts 25 extract which may be used alone, or in-combinaof the extract in respect of the powdered fuel tion with a colloidal clay such as, for example, ay b s d t i is n s a y s a y, bentonite. about 3% to 5% bywelght of extract inrespect v The quebracho extract is employed, preferably, of the powdered fuel is suflicient. The bentonite, in association with a carrier, such as water, in w e used,may a so v ry from about 2% to about 30 sufiicient quantity to carry it through the mass by Weight and hig rn t e powdered fuel of powdered fuel to be formed into thebriquette. l h h. usually, good r u s r tained When The commercial quebracho liquid extract may be the bentonite varies from about 2.5% to about 6% i used as such, ifdesired, or the dry extract may by weight of the fuel. Briquettes formed by the be employed, as hereinafter indicated. If a carid Of a bin e co p is quebraoho extract and 5 rier is employed, the quebracho extract-may be b n ohi e in accordance With 0. nt onlare first dissolved therein'to form a solution and the substantially free from any t nde y t w rd solution mixed with the powdered fuel, or the ormat n o y ash a dusting; v carrier and quebracho extract may be separately h f llowin e illust ativ examples Of el 40 added to powdered fuel. The former practice mixes which can be compounded into briquettes 40 is preferred. The quebracho extract or aqueous in c or n wi h Our invention. It is to be solution thereof normally .has a pH varying in the understood, however, that our invention is not order of from about' to about 5. While this I to be construed as l mi d y h e ific de ails extract or solution of pH 4 to 5 may be used in of these examples. l accordance with our invention, we prefer to use Example 1 r 4 an extract or solution having a higher pH in the parts by weight of powdered charcoal are Order of from about 6 to about Thus the mixed in a suitable vessel with a binder consi tdrogen ion concentration of the extract or solum r s g of 3 parts by weight of bentomte in 7 partsmay be adjusted to the desired pH by means by weight of a 307 aqueous solution of quebracho of any suitable alkali such as, for example, sodium extract'having 5 of 12 to form a m e1 hydroxide, sodium carbonate, ammonia or the like, care being exercised to avoid the use of such v qz. V

an excess of alkali as tofiocculate the quebracho 90 parts by weightof a mixture of 70 partsby extractives and/or bentonite. We have found weight of powdered charcoal and 20' parts by that the best results are obtained when the exweight'of powdered coal are mixed in a suitable ll Example 3 parts by weight of powdered coal are mixed with 10 parts by weight of a,40% aqueous solution of quebracho extract, in a suitable vessel, to form a. fuel mix.

In preparing fuel briquettes, the fuel mix prepared in accordance with our invention as above set forth, is introduced into a briquetting machine in any desirable manner and thebriquettes are formed by pressing the fuel mix at a suitably high pressure, in the order of about 2,000 lbs. per square inch and preferably higher. The briquettes, as they are removed from the machine, are self-sustaining and strong enough to handle. They are .then permitted to air-dry at normal room temperatures for several hours during which time the binder sets, forming very hard briquettes.

The briquettes produced our invention burn very readily and hold together during burning thereof. .Due to the binder employed by us, fly ash, soot and dusting are almost entirely eliminated. Moreover, the briquettes are extremely hard and the individual particles of fuel are so strongly held together that the briquettes, when dry, will withstand rather high pressures, in the order of about to about 200 lbs. per square inch. Even the wet strength of the briquettes produced in accordbonded together with a binder in accordance with ance with our lnventionis higher than that of any of the heretofore known briquettes. In addlticn, due to the quick drying tendencies of our briquettes at normal room temperatures, we have materially lessened the usual cost of manufacture thereof since the need for costly drying ovens is eliminated.

By the expression powdered fuel" as used in the specification and claims. we mean any solid powderedburnable material useful as a fuel such as charcoal, coal, coke, sawdust and the like.

We claim:

1. A fuel briquette comprising powdered fuel comprising quebracho extract and bentonite.

2. A fuel briquette comprising powdered fuel bonded together with a binder comprising deflocculated quebracho extractives and deflocculated bentoriite.

3. A binder for powdered fuel comprising quebracho extractives and bentonite.

4. A binder for powdered fuel comprising an aqueous solution of quebracho extract and bentonite suspended therein, said solution having a pH of about 6 to about 12.

5. The method of forming fuel briquettes which comprises mixing powdered fuel with a binder comprising an'aqueous solution of quebracho extract and bentonite, said solution having a pH of about 6 to about 12, pressing said mixture to form briquettes and drying the briquettes so formed at normal room temperatures.

GREGORY G. RICK. CHARLES E. LOETEL.