US1990405A - Method of making briquettes - Google Patents

Description

Patented Feb. 5, 1935 I v UNITED STATES PATENT oFF'lcg METHOD OF BRIQUETTES No Drawing; Application August 22, 1930, Serial No. 477,193. Renewed July 10,1934

6 Claims. (01. 44-23 My invention relates to, a novel and improved sense, since it includes the change from a low briquette and to the method of manufacturing melting tarto a high melting tar regardless of it, and more particularly it relates to a briquette the phenomena involved, which may include an in which a novel type of binder is employed. oxidationreaction as well as possibly one of re- One object of my invention is to provide a wa- (motion. The tar and pitches applicablefor'use 5 ter-resistant, odorless, and commercially smokeaccording to the present invention may be'desigless briquette which is strong, hard and resistant nated aslow melting tars capable of polymeriz to abrasion, and which can be manufactured at ing under heat and oxygen to form relatively a relatively low cost. high melting tars. v

10 Another object of ,r'ny invention is to provide a As examples of tars which may be used, steam 10 coherent'mass, or briquette, compounded of finely refined asphalt and Water-gas tar are men'- dividedpulverulent materials and a binder whose tioned'. The former has a melting point (ball'and melting point at the time that it is mixed with ring) of 120-125 degrees F. and a penetration the finely divided materials is relatively low, but of85-100 at 77 F. (100 grams, 5 seconds). It

which during the process is converted into a nonis usually obtained as a product or by-product of coked binderof relatively high melting point. the distillation of as'phaltic base crude oil. The

Stillanother object is to provide a method of .wat'ergas tar has a melting point of 100 to 110 making briquettes in which it is possible to uti degrees F. and a specific gravity of 115-120.

lizethe low melting tars and pitches which have It is a product or by-product of the manufacture not heretoforebeen considered applicable for use of 'carbureted water gas in a carbureted water- 20 as the main binding material. gasplant, and is usuallyextracted from the waterj Other. objects will be apparent from a congas operation .whena heavy oil commonly called sideration of the specification and claims. bunker C oil is used in carburetion. It is ap- Briquetteshave heretofore been manufactured plicable for use without further distillation or by the use of pitches and tars of relatively high treatment. In addition to these two tars men- 26 melting point, the use of which has required a tioned', various lignite; shale and coal tars are considerable amount of heat to render them fluid applicable. I I v and to keep them in this condition during the A wide variety of materials may be formed mixing preparatory to the pressing operations. into briquettes by means of the tars. herein con"- 30 Diiiiculties are encountered for this reason,since templated. For example,'the resulting coherent 30 the binder tends to set or solidify before a mass may be briquettes of ore, flue dust'or conthor'ough mixing is obtained and before the centrates; bricks or cores of" sand or gravel or briquettes are molded to the desired form. The other jfinely divided pulverulent materials; or low melting tars and pitches have not been used fuel briquettes of coal dust or coal fines. The

as the main. binding materiaLlsince they'have term finelydivided particles used throughout 35 been'considered too soft and fluid 'forthe purpose, the specification and claims includes granular, due to the ,diificulty of handling the pressed powdered, pulverized and other finely divided briquette, their susceptibility to temperature material. changes near the melting point, and their tend- In carrying out my invention, a briquette is 40 ency to disintegrate under firingconditions. molded to the desired size and shape, using as .40

Myinvention is characterized byanew andimthe bindingfrnater'ial' a low melting tar of the proved method of adapting low melting tars and characteristics previously described; The mass pitches for use in the manufacture of coherent is then subject'ed'to heat and oxygen which may masses, or briquettes. My invention contembe supplied by. the air passing through the heat plates the utilization as binders in briquette makzone, or from any] other source, for a sufficient 45 ,5 of w melting t a D ches, such for time to polymerize'the low melting tar and'to reexample, as those that melt below 125 degrees F., move the smoke-producing constituents. In the but which materials are capable of change under heat and oxygen treatment, there is an exothe influence Of heat a d Oxygen to a non-coked thermic" reaction involved which automatically binder of relatively high e ting point with the raises the temperature in the heat zone. The 50 smoke-producing Constituents emoved. The binder throughout the brique'tte due to, its gaschange from the low melting. tar to the high pervious nature is converted to one of high meltmelting tar under the influence of heat and oxying point and no appreciable amount of coking gen is termed herein polymerization. The takes place. The cohesive'qualities of the binder term, however, .is not necessarily usedin its strict are, therefore, not destroyed. It is possible by 55 In most cases a temperature of from 450 to 550 degrees F. and a time interval of from 30 to 90 minutes is sufiicient to cause the desired polymerization if the air admitted (and passed through the mass of briquettes isradequate to produce an oxidizing atmosbhereinthe heat zone; The size, weight and shape determine to some extent the time necessary to cause the polymerization. A pressure slightly above thatof the atmosphere is preferably maintained and the use of preheated air is found to be advantageous. The percentage of tar relative to the finely divided materialflvaries wide1y,.depending upon the na-- ture'ofthe materials. In most instances the percentage-of tar is between 3% and 15 by weight of the pulverulent'material.

In a typical case the use of anthracite coal in finely divided form and steam refined asphalt one. melting 'point of '120e-125 degrees F; and a penetration of 85 to 100 at 77 F. (100 grams, 5 seconds) will be described. The tar is employed in a percentage from 5% to 7% by'weight of themcoal particles. {The two ingredients are thoroughly-mixed either hot or cold as best suits conditions.- In most instances it will be found desirable to raise the temperature of the coal and tar to, apoint where full advantage of the capillary attraction and'aifinity of the materials toward eachother is obtained, thus assuring a thorough and uniform mixture and the covering of each particle 'with a thin film of the tar. The briquettes are then formed under pressure by placing the mass in molds of the desired shape and size.. The formed masses'are placed 'on a per forated conveyor or wire screen to allowfree paSSfiof air and heat through the mass of briquettes. Preferably a conveyor is employed which travels in a horizontal plane or in an inclined plane of such inclination that the position of the soft briquettes isnotchangeduntilthey arestr'ongind hard, due to the polymerization. The briquettes are passed through a heat zone maintained at a temperature in the neighborhood of 500 degrees F, for a period of '75 minutes, during which time a volume of preheated air is admitted in suitable quantities and passed through the heating zone to produce an. oxidizing atmosphere of slightly greater pressure than that' of the atmosphere of the surroundings. The bri-' quettes are allowed to cool, and they willbe found to" have the qualities hereinbefore described. Considerable modification is possible in the type of low melting ta'r used, in the ratio of tar topulverulent material, and'inthe temperature, time and oxidizing conditions employed, since these factors depend to a large extent on the type of .tar utilized, as well as on the size, weight and"shape of the briquette, without departing from the essential features of my invention. Iclaim'zfi V 1'.fThe process of making briquettes,. which comprises covering finely dividedparticles tobe agglomerated with a thin film'of a tar whose melting point is below approximately 125 degrees F. and which is capable of polymerization under simultaneously applied heat and oxygen to form a relatively high melting point tar with the smoke-producing constituents removed, forming the particles into gas-pervious masses of desired shape and size, and thereafter subjecting the formed masses at a temperature of at least 450 F. to intimate and direct contact with oxygen by passing a current of an oxygen-bearing gas through and around the masses during the heata ing, the heat and oxygen treatment being sufficient to cause polymerization to convert the low melting point tar'into a tar of relatively high melting point with the smoke-producing constituentsremoved said treatment being insuflicient to destroy the binding properties of the tarand' to bring about coking thereof.

2. The process of making briquettes, which comprises covering finely divided particles to be agglomerated with a thin film of steam-refined asphalt whose melting point is below approximately 125 degrees F. and which is capable'of polymerization under simultaneously applied heat and oxygen; to form a relativelyhigh melting point'product with the smoke-producing constituents removed, forming the particles into gasp ervious masses of desired shape and size, and thereafter subjecting the formed masses at a temperature of at least 450 F. to intimate anddirect contact with oxygen by passing a currentj-ofi'an oxygen-bearing gas through and around ,the masses during the heating, the heat and, oxygen treatment being sufficient to cause polymerization to convert the steam-refined asphalt into a product of relatively high melting Point with the smoke producing constituents 1 removed} said treatment being insufficient to destroy the binding properties of the asphalt and to bring about coking thereof. ,7 l

3; The process of .making briquettes, which comprises covering finely divided particles -to be agglomerated with 'a thin film of a'wateregas' tar whose melting 'point is belowv approximately 125 degrees F. and which is capable of polymerization under simultaneously applied heat and oxygen to form a relatively high melting point tar with the smoke-producing constituents removed, forming the particles into gas-pervious masses of desired shape and size, and thereafter subjecting the formed masses at a temperature of at least 450? F. to intimate and direct contact with oxygen by passing a current of an oxygen-bearing gas through and around the masses during the heating, theheat and. oxygen treatment being sumcient to cause polymerization to convert the water-gas tar into a tar of relatively high melting point with the smoke-producing constituents removed, said treatment being insufiicient to destroy the binding properties of the tar and to bring about coking thereof. V I

4. The process of making briquettes, which comprises covering finely divided particlestobe agglomerated with a thin film of a tar whose melting point is below approximately 125 degrees F. and which is capable of polymerization under simultaneously applied heat and oxygen to form a relatively high melting point tar with thesmokeproducing constituents removed, forming the particles into gas-pervious masses of desired shape and size, and thereafter subjecting the formed masses to a temperature between 450 degrees F. and 550 degrees F. in the presence of an oxygenbearing gas passed through V and around the masses for a period of time between thirty and ninety minutes to cause polymerization to convert the low melting point tar into a tar of relatively high melting point with the smoke-producing constituents removed, said heat and oxygen treatment being insufficient to destroy the binding properties of the tar and to bring about coking thereof.

5. The process of making briquettes, which comprises covering finely divided particles to be agglomerated with a thin film of steam-refined asphalt whose melting point is below approximately 125 degrees F. and which is capable of polymerization under simultaneously applied heat and oxygen to form a relatively high melting point tar with the smoke-producing constituents removed, forming the particles into gas-pervious masses of desired shape and size, and thereafter subjecting the formed masses to a temperature of approximately 500 degrees F. in the presence of an oxygen-bearing gas passed through and around the masses for a period of time of approximately seventy-five minutes to cause polymerization to convert the steam-refined asphalt into a product of relatively high melting point with the smoke-producing constituents removed, said heat and oxygen treatment being insufiicient to destroy the binding properties of the tar andto bring about coking thereof.

6. The process of making briquettes, which comprises covering finely divided particles to be agglomerated with a thin film of water-gas tar whose melting point is below approximately 125 degrees F. and which is capable of polymerization under simultaneously applied heat and oxygen to form a relatively high melting point tar with the smoke-producing constituents removed, forming the particles into gas-pervious masses of desired shape and size, and thereafter subjecting the formed masses to a temperature of approximately 500 degrees F. in the presence of an oxygen-bearing gas passed through and around the masses for a period of time of approximately seventy-five minutes to cause polymerization to convert the low melting point tar into a tar of relatively high melting point with the smoke-producing constituents removed, said heat and oxygen treatment being insuiiicient to destroy the binding properties of the tar and to bring about coking thereof.

WILLIAM L. HOERNLE.