US1678863A - Method for the preburning preparation of fuels - Google Patents

Description

Patented July 31, 1928.

UNITED STATES PATENT OFFICE.

JOSEPH MOSES WARD KITCHEN, OF EAST ORANGE, NEW JERSEY.

METHOD FOR THE PREBUBNING PREPARATION OF FUELS.

one-half of the coal that is mined becomes lost to the use of man, and that the causes of such losses are various, and need removal. Among the losses, is the fact that much the largest part of the crude coal deposits produce smoke in their burning, are usually incompletely burned so far as the gases evolved in their use is concerned, that some of them including so-called steaming coals, in their fracturing into graded sized particles, roduce a large amount of small sized particles including dust, that in high-volatile bituminous coals their volatile oily content is in such excess amounts that they swell, crumble and more or less melt in their burning and compact the fuel-mass, and form slag, clinkers and funnels and hence pass excess air for combustion thru such fuels when in fuel-masses. Above all other causes, is the fact of the widespread ignorance of coal users as to the nature of combustion processes, and the need of economy in the use of fuels both for present day and future uses of the world. As the result of such conditions, the present day does and the future day world will suifer'not only great waste of fuel and damage to health; but also, mining interests produce and accumulate large amounts of fuel-culm particles that are little used, and when used, only sell for very low prices as compared with high cost graded anthracite, smokelessly burning coal.

What I propose as a remedy for this situation is practically possible because of the fact that while anthracite coals only have from 3% to 7% of volatile content and do have a large ash-content, the soft coals con tain from 20% to 40% ormore volatile content but lesser ash content, are more easily mined and are hence produced at a lower cost per volume of weight. Also, anthracite fines and'dust, and lignite coals can be purchased at very low figures. But such. low cost materials in crude form when burned in masses, become compacted and are so lacking in porosity that air for combustion does not easily find access into or thru such compacted materialsointo contact with the surfaces of the fuel articles.

My inventive remedy for t' e latter situation is in part to so harden soft coal by 5, 1926. SerialNo. 139,760.

its more or less coking that it will not swell, crumble and melt so as to effect compactive clogging of the fuel mass to gas passage as occurs in the use of these crude soft coals; and then use the coked fuel to give porosity to fuel-masses that otherwise would be lackmg in porous texture, the process being either thru admixture, or thru special production of new forms of fuel.

I use for my purpose, cokes of various degrees of hardening-carbonization as basic constituents in mixed fuel-masses, and in new solid fuels. lVith coke basic frameworks in fuel-masses, which may be replaced with hard particles of anthracite or graphitic coals, I admix enriching particles of uncoked coals richer in volatile content, such as bituminous slack or anthracite or semi-bitumlnous fines, in varying proportions that are in accord with the method I use in burning such fuels. In using induced natural draft in ordinary methods of burning, only a smaller proportion of the enriching constituent is used than if a mechanically forced draft is used. In the latter case, a larger bulk proportion of soft coal or anthracite fines may be used.

As a special rule, I adniix relatively large sized graded particles of coke with smaller sized particles of enriching ingredients. I may have the large sized coke or hard coal basic particles in juxtaposed contact, and only occupy a part of the intertices between the larger sized particles, with the smaller sized cnriching particles. This prevents the smaller sized particles from becoming compactly compressed. In other. cases I completely fill, and more than fill the interstices with enriching small particles. I may enrich the coke by impregnation with low cost heavy fuel-oils, and use such impregnated coke as a gas-forming and. enriching fuel. I may make thoroughly admixed mixtures of coke, high-volatile bituminous and anthracite dust, as a gas-forming fuel, and subject such mixture, with or without fuel oil impregnation, to heat in a gas retort or on a traveling grate, and heat and drive ofi some volatile matters from the admixture and melt the high-volatile bituminous constituent, which then incorporates with the anthracite dust and agglutinates with the coke, the agglutinated material being partly absorbed into the coke thru the capillary attractionof the coke. Ihis makes a. byproduct fuel, the heat of which. when IOU cooled by steam, forms water-gas, that may be admixed with other gases driven off from the mixed fuel in its heating, in a gas retort or on a traveling grate.

I make some mixtures that are of a character specially suitable for banking fuels. For example: I admix moderate or small sized graded hard (anthracite or graphitic) coal particles, and crushed coke or coked breeze and anthracite dust in sufficient amounts and in correct proportions, to substantially fill all of the interstices between the hard coal particles, and thoroughly moisten the entire mixture. This makes an excellent banking fuel for various purposes, including the repression of the rates of combustion, in greenhouse boilers during daylight hours, and also for banking domestic furnace fires during night sleeping hours.

I admix coke with fuel dust that ismoistened so as to prevent the flying of dust and cinders in the burning of such mixtures,

either in the use of induced natural draft, or with mechanically forced draft. In this case the moistened dust adheres to the rough coke pores and surfaces, and leaves the intercoals.

spaces more or less open. IVith forced draft, such mixtures in enormous quantities can be burned with advantage.

I admix large sized particlesof coke or hard coal with small sized anthracite or medium or low-"olatile semi-bituminous soft By frequent or continuous feeding of such mixtures, large amounts of such fuels can be utilized thru the use of strong forced draft projected upwardly into the mixtures, and thus securing great economy in the cost of fuels thru such practice. In such mixtures the smaller sized particles of coal burn more quickly than the larger sized particles, which larger sized particles gravitate to the grate line before bccoming'entirely burned, and there form a bed-shelf or platformresting on the grate, which intercepts and holds any unburned smaller sized particles until they are entirely burned. This prevents grate sifting of the smaller sized particles. Large amounts of such low-cost fuel materials can thus be used.

Mixtures of coke or hard coal in large sized particles and in moderate bulk amounts and high-volatile connninuted or slacked bituminous coals in larger bulk amounts, I

burn in heaps with or without forced draft; in which case, the heaps burn from their under surfaces, the gases and vapors escaping by a horizontal travel thru the interstices between the large sized coke particles to the peripherv of the heaps, where more air rises thru the grate and becomes admixed with and burns with the unburned volatilized matters, and at which peripheral oint, other air can be forced into quick and intimate contact with the vapors and gases in the combustion space. The heat of complete combustion produced at such pomts, is usually in close contact with the heating surfaces, and is there absorbed progressively in the gravitational rise of the burned gases against the heating surfaces.

In my copending applications Ser. Nos. 703,006; 706,201; 710,426; 717,197; new Ser. Nos. 67 ,182 and 239,964, I describe and illustrate how I admix air with burnable gases in connection with various forms of stationary and moving'grate's, and secure substantially eonipletecombustion of my preburning prepared low cost or other fuels.

In the mixtures I use, I secure thru uniformity of texture a greater uniformit of rates of combustion in all parts of the fuelbed, and thus avoid the losses due to the passage of excess air of combustion thru the fuel-bed,and due to unequal combustion in various parts of the fuel-bed.

'Thoroughncss of admixture of the constituents of my fuel mixtures is of great importance, and on that account I preferably use mechanically rotating mixers to secure such uniformity of texture in fuel-masses. This uniformity of texture prevents the formation of air-passing funnels, and also. formation of masses of slag in the fuel-bed. 1 In my copending application Ser. No. 697,769, I describe and illustrate how I convert admixed fuels, including coke impregnated with heavy fuel-oils, into low cost fuelgases of various thermic values. and incidentally produceas a byproduct, the low costsmokelcss solid fuel claimed in the present application. In that process heat developed in the process is converted into water gas. The same solid fuel can be produced on traveling grates as a byproduct in generating steam for process or power uses. the b vproduct fuel being used in cycle with repeated enriching admixtures with high-rob atile bituminous fuels. 7

In my copending applications Ser. Nos. 703,000; 706,201; 710,496; 717,197 and 67. 182, I disclose and claim special methods of burningmy fuel mixtures under mechanically controlled draft by introducing air for combustion into and over fuel-masses in specially desired amounts at specially selected points of air introduction. Such methods are a part of the present invention.

In the copending application Ser. No.

697,769, I describe preferred methods of producing various fuel products in one special apparatus, in which gases of various chara ters as wellas solid fuelsare economicallv produced, and in which the heat of the prodess is utilized regeneratively in producing water gas, as well as in cleaning gases. In the present case, "my claims are restricted to producing the special fuel roducts herein described as s ecific fuels, al of which have special value or special purposes.

The degrees of heat I apply to soft coals in their hardening will vary according to the nature of the coke product wanted. High temperature coke is of special value for impregnation with fuel oils. Lowtemperature carbonized coke is good to use in mixtures for generating producer or other gases if impregnated with fuel oil; or, after crushing, for admixture with other solid fuel materials. So long as the porosity of a fuel-mass is attained and maintained to secure a sufficient heating effect, the more volatile enriching matter added to the hardened fuel, the better.

What I claim as new, is:

1. The method which consists in mixing coke of relatively large sized particles, highvolatile bituminous coal particles of relatively smaller size, and anthracite dust, subjecting the mixture to a bituminous-coalmelting temperature, and cooling the product of the process.

2. A new fuel which consists of coke particles having agglutinatively adherent to the coke particles, agglutinated high-volatile soft coal and hard coal dust.

3. The method which consists in producing a liquefied form of high-volatile soft coal. securing the agglutinated absorption by and adherence of the liquefied coal with coked particles of coal, the process including a preliminary melting-heating of the soft coal and its subse uent cooling and hardening.

4. A new fuel composed of particles of hard coke, coated with adherent soft coal that has been liquefied by heating and subsequently cooled.

5. The method which consists in heating and coking a mixture of large sized particles of coked coal and small sized particles of high-volatile soft coal and producing a volatilized burnable gas from a part of the volatile content of the mixture and a liquefied adherence of a part of the high-volatile constituent of the mixture to the coked coal.

6. A new fuel byproduct secured by admixing particles of coke and soft coal, subjectin the admixture to a meltin and volati e-volatilizing heat and gasifymg a agglutinated coke and unutilized aggluti-.

nated soft'coal.

7. The method which consists in liquefying a soft coal and securing the absorptive adhesion of the liquefied soft coal with particles of coke.

8. The method which consists in coking soft coal sufficiently to harden the coal, admixing the coked coal with comminuted particles of soft coal and other enriching coal product material, bringing the admixture to a liquefying temperature and agglutinating the liquefied material and the sufiiciently hardened coal, and hardening the agglutinating material by cooling.

9. A fuel composed of coke agglutinated with hardened melted coal materials containing highvolatile soft coal.

10. A fuel com osed of coke impregnated with cooled lique ed soft coal.

11. A particle of coke having agglutinated with the coke, dry adherent soft coal.

12. A fuel-mass composed of admixed particles of coke and comminuted small particles of semi-bituminous lowvolatile coal.

13. The method which consists in mixin coke particles of relatively large size, so coal particles of comminuted or slacked sizes smaller than the coke particles and fuel oil, subjecting the mixture to a soft-coalmelting heat until the soft coal melts and becomes agglutinatively adherent with the coke particles.

14. The method which, consists in mixing particles of high-temperature coke of relatively large size and particles of soft coal moistened with a petroleum oil fractionate, subjecting the mixture to a soft coal melting and volatile-volatilizing heat and volatilizing and gasifying part of the mixture and agglutinatin the balance of the coal into adherence with the coke particles, and cool ingl'l with steam the agglutinated coke and soft co JOSEPH MOSES WARD KITCHEN. I