US2125897A - Apparatus for the thermal treatment of carbonaceous materials - Google Patents

Description

B- 1938. a. F. N llCHOT-DUPONT 2,125,897 APPARATUS FOR THE THERMAL TREATMENT OF CAHBONACEOUS MATERIALS filed Oct. 151935 2 Sheets-Sheet 1 kW 2 AN;

v v a Aug. 9, 1938. G. F. MlCHOT-DUPONT I APPARATUS FOR THE THERMAL TREATMENT OF CARBONACEOUS MATERIALS 2 Sheets-Sheet 2 Filed Oct. 15, 1935 o furnace.

' Patented Aug. 9,1933

, APPARATUS FOR THE THERMAL TREAT- MEN']! OF CARBQNACEOUS MATERIALS Georges Francis Michot-Dupont, haalis, France Fontainc- Application October 15, 1935, Serial No. 45,071

- In France February 21, 1935 3 Claims. .(Cl. 202-111) The pre'sentinvention relates to furnaces for bonaceous materials such as various oils, schists,

lignites, peats, bitumens, or the like as well 5 as'artificial mixtures of more or less fluid liquide with an active or inert support; and it is particularly but not exclusively concerned with low temperature distillation.

The principal object is to provide apparatus which, by means of an installation having a reduced space relative to the mass of the materials to be treated in a given time, permits products of which the quality is improved and the output increased relatively 'to the apparatus utilized heretofore, to be obtained with a high calorific efliciency.

The method according to the present invention consists in submitting the materials to be treated, in separate portions and traversed in a continuous manner and at the desired speed, to a progressively increasing heating, in producing the circulation in counter current of the products emanating from these materials by reason of the heating, in contact with said products and in evacuating the said products at at least one point of the path followed by the said materials.

The apparatus used for carrying out this method includes means for traversing, in a continuous manner and in the form of separate portions,the materials to be treated through a conduit heated on the one hand exteriorly and on the other hand by the hot products resulting from the thermal treatment of the said materials and traversing the latter in counter current while being maintained preferably out of contact with the walls of the said conduit and, at at least one point of this conduit, an outlet .for the said products with a view to their recuperation.

In order that the invention may be fully understood it will now be described with reference to the accompanying drawings, wherein:-

Figs. 1, 2, 3 and 4 show respectively in longitudinal section along -I-I Fig. 2, in transverse 4 section along II-II Fig. l, in plan and in rear view, a furnace constructed according to a first embodiment of the invention.

Fig. 5 shows in perspective a part of the driving or traversing mechanism utilized for the said Fig. 6 shbws in elevation (parts in section) a furnace constructed according toa second embed-- im'ent of the invention.

The invention will be further described in its 5 application to a furnace for the low temperature distillation of solid or pasty carbonaceous substances.

The furnace is constituted by a long conduit 11 having for example an internal diameter of about (3.15 to 0.20 meter and a'length of about 5 to 6 meters and the said conduit is provided at one extremity with a charging orifice 2 having a funnel 3, and an emptying orifice 4 with a discharge conduit 5 at the other extremity. The conduit itself may be rectilinear, curved in the form of a 10 U -(-Figs...l to, 5), or it could have any suitable elongated form whil'e'be'in'g arranged horizontally or obliquely. One could also form theconduit as shown in Fig. 6, in such a way that the greater part of its length has the form of a helix or coil with large spirals, the axis of the helix being disposed vertically, horizontally or obliquely.

The materials are driven in a continuous manner and at the required speed, for example between 0.8 and 0.2 meter per second by suitable 20 propelling or traversing means. Advantageously these means are such that the materials during their passage through the conduit i are maintained separated into small distinct portions offering a great surface; and facilitate the propelling through the tube I. Y

These means may be constituted by discs having a form corresponding to that of the section of the tube l and dimensions a little smaller than these of the said section to prevent any wedging. These 30 discs 6 function as driving members and are connected together by one of more links I (Fig. 5) which engage freely inthe connecting members 8 fixed to the corresponding face of each of the discs 6. The distance separating two adjacent discs may be for example, about 20 cm.

An endless chain is thus formed by means of the articulated discs 5, which chain is driven in a continuous manner in the conduit l constituting the furnace, by a suitable power mechanism, such 40 as a wheel f which the shaft I0 is operated by a motor and which carries radial blades ll. Two adjacent blades are separated from one another 'by an angle corresponding substantially to the space between two adjacent discs 6.- The wheel 5 9 is arrangedjin such a way that the part of the chain located between the outlet and the inlet of 4 the tube is engaged on the periphery of the said wheel and is driven by the radial blades II. It should be understood that one could adopt any other method of operation for these propelling members, particularly by taking account of th iorm which is adopted for the conduit l.

As thechambers l2, formed between the pairs of neighboring discs 6 pass below the funnel 3,

The driving by these discs of small distinct masses also presents the advantage that the materials under treatment progress uniformly in the furnace without being re-mlxed and without being subjected to agitation, thus avoiding the formation of dust. Further, these materials have a very largesurface forthe gas evolution and a good permeability to heat.

Fluid-tightness of the apparatus is ensured by a mass of water or other suitable liquid contained in suitable receivers such as I! and 20 and in which dip the inlet and outlet orifices of the propulsion system as well as the evacuation orifice of the residual materials.

The heating of the tubular furnace thus obtained is effected in part by afluid at a high temperature, such as the'gases resulting from the combustion .of gaseous liquid or solid (pulverized) fuel, which is caused to circulate in chamber it which surrounds the tubular furnace,

the said chamber l3 having the form of a tubular envelope arranged at' the exterior and along the tube in the case of Figs. 1 to 5, while for theexamplejccording to Fig. 6, use is madeof' a true chamber I! in which is located at least a part of the tubular furnace in the form of a helix or coil.

The circulation of the hot fluid in the chamber I I is effected in the opposite direction relative to that adopted for the materials driven in the furnace. To this end and for the example according to Figs. 1 to 5, the burner or burners II or the like are arranged in such a way that they open into the chamber it near the emptying orifice 4, while the evacuation of the hot fluid in the discharge conduit or flue I5 is effected near the entry orifice 2. In this way a progressive (that is to say without sudden variation) heating of the materials while they advance in the furnace is obtained, since the materials which are ready to leave the latter are heated by the fluid at high temperature, the temperature of this fluid falling little by little towards the point It, where its evacuation is eifected.

Hotthe example according to Fig. 6, the burners or the like I are arranged at the base, and at the central part of the chamber in such a way that the hot gases can rise freely in the interiorof the assembly formed by the spirals of the coil or the like I and descend at the exterior thereof so as to be evacuated'by the chimney II. In this way the hottest gases come into contact with the lower spiral or the outlet of the tubular furnaceand they are cooled as they approach the upper spiral or entry of the furnace.

One could utilize for the external heating such as described above, electric resistances arranged at the exterior of the furnace and, in order to obtain the same progressive heating efl'ect, these resistances could be graded in such a way as to heat the furnace more strongly at the outlet than at the inlet.

Besides the exterior heating there is provided according to the invention an interior heating by the gases and vapors emanating from the treated materials and resulting from the distillation. To this end there is provided in eachv of the discs 6, one or more central orifices 6, by which the said permanent or condensable.

conduit. Further, one could circulate these distillation gases by the effect of the depression existing in the condensing apparatus referred to below, by a current of water vapor or any other fluid introduced by an orifice at a suitable point of the furnace. The circulation is effected in such a way that the gases are directed towards a less hot zone than that which has produced them, and they thus give up their heat to the material in course of treatment. These gases thus serve in some ways to balance the temperature of the mass advancing in the furnace, the equilibrium of the calorific exchanges in the interior of the furnace being obtained by giving up the heat by the gases produced in the hottest zones to the materials to be treated which are thus heated more economically.

At suitable parts of the tubular furnace and preferably towards the part forming the entry of the furnace, there may open in the upper part of the conduit I one or more tubes It by which the volatile products resulting from the treatment may escape by the common or separate conduits I'I opening for example into one or more condensers l8 of any suitable type.

As a result of this arrangement a furnace is obtained permitting the treatment of all carto a minimum in order to avoid encumbrance,

losses of heat, costly maintenance and so on. Further, the mass of the materials under treatment is great relatively to the mass of the apparatus, a. machine, weighing for example 500 kilograms, being adaptedto treat about 3,000 kilograms of lignite per day.

The furnace as constructed is, suitable, not only for the thermal treatment of carbonaceous materials subjected to a distillation, but these materials can also be treated in a furnace with solid, liquid or gaseous bodies adapted toreact thereon (for example byhydrogenation or methylation) according to the purposes proposed. Thus, the furnace permits an auto-cracking of the heavy gases which condense in the coolest'zones of the treated materials and return with them towards the hottest zones. Further, one could obtain a hydrogenation without the effect of pressure by introducing water vapor in the hottest part of the furnace in which there is for example a. temperature of about 900 C.

What I claim is;

1. A retort for the thermal treatment of carbonaceous materials comprising an externallyheated conduit having a relatively hot end and a relatively cool end, material feeding means near the cool end; a conveyer moving through said conduit from the cool 'end towards the hot end thereof, said conveyer comprising a series of centrally-apertured plates, profiled to conform closely-to the inner contour of the conduit, and connections between said plates positioning them in spaced relation and crosswise of the conduit; and an offtake for gases evolved from the material as it travels through the conduit positioned well in advance of the hot endthereof, whereby gases evolved in a hot zone are forced to flow in counter-current to the material in order to reach said oiitake, passing axially through the retort and the material being treated, by way 01' the apertures in said plates, so that said gases are protected from contact with the hot retort walls, and their temperature is lowered while increasing the temperature of the oncoming material.

2. A retort for the thermal treatmentv of carbonaceous materials comprising a conduit havinga relatively hot end and a relatively cool end; a feeder for the material to be treated, near the cool end; an ofitake for gases evolved from the material upon heatin locatedwell in advance of the hot end of the conduit; and conveyer means in said conduit profiledto conform closely to the inner contour thereof, but constructed and arranged so as to provide a passage spaced from the conduit walls, through which the evolved gases must pass in order .to escape from the hot endto the ofitake.

,3. A retort for the thermal treatment of carbonaceous materials including a conduit, means for externally applying heat to the conduit, conveyer' means in the conduit including a plurality of conveyer plates, positioned generally crosssectionally of the condult,.and means for moving the plates through the conduit in spaced relation to provide a plurality of conveyer pockets therebetween, the conveyer plates being profiled to conform approximately to the inner contour of the conduit and having apertures there'- through spaced from the periphery thereof, feeding means toward one end of the conduit for substantially filling the conveyer pockets with material to be treated, and a gas ofitake from the conduit positioned well in advance of the delivery end thereof, whereby vapors evolved from the material under treatment toward the delivery end of the conduit are caused to pass to said ofitake in counter-flow through the material in said pocketsand substantially out 01' contact with the conduit walls.

GEORGES FRANCIS MICHOT-DU'PONT.

Images