Combustion chamber for combustion disposal of waste mineral bearing streams

In the combustion of waste mineral-bearing liquid streams, an improved type of construction for the combustion chamber, for the combustion of waste mineral-bearing liquid streams which permits continuous removal of solid particulate waste. An annular water channel is fitted inside of the outer shell of the combustion chamber at the bottom. The bottom of the chamber is closed off with a funnel-shaped, inverted conical floor, having a drain outlet at its center. An opening is provided in the side of the combustion chamber just above the bottom, for the exit of downflowing products of combustion. Water is supplied to the annular channel and flows through a longitudinal gap in the inner wall, to fall onto the funnel-shaped floor plate, to wash down all of the particulate matter that collects on the bottom plate, into the drain. Thus, the waste is removed as it is formed. The refractory lining of the chamber is shaped with an inwardly-directed flange to permit the flow of molten material down the refractory surface onto the funnel-shaped floor plate and to protect the water channel from direct heating by the flame in the cumbustion chamber.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention lies in the field of waste disposal. More particularly, it 
concerns the disposal of liquid streams that have metal salts in solution, 
as well as particulate waste. 
2. Description of the Prior Art 
Combustion gas flow stoppage, or incremental obstruction of the flow paths 
for the gas, has, in the past, very seriously interfered with disposal of 
liquids which are mineral-bearing and also are industrial wastes. The best 
and most accepted method of disposal has been by introducing the liquids 
to a combustion zone in the form of a fine (micron size) spray where the 
heat-induced reactions typical of a combustion zone cause the radical of 
the mineral salt to first oxidize and then, due to the presence of 
CO.sub.2, to form the carbonate of the mineral (metal) radical, at or near 
to exit from the combustion zone. The carbonate (or bicarbonate) persists 
in the gases resulting from combustion as either molten solid, or as a 
particulate solid, according to the retrograde temperature level. If the 
solid is molten and strikes the side of the combustion chamber, it clings, 
to run down the sides of the combustion chamber to accumulate on the floor 
of the combustion chamber. The unmolten solid matter (carbonate or 
bicarbonate) also adds to the solid accumulation via `drop-out` or other 
effect, in such a manner that in varying times, which can be as little as 
36 hours, the gas passage becomes essentially closed and disposal must 
cease. 
This condition is intolerable because the blockage thus described occurs at 
or on the bottom of the combustion chamber, as the pile rises, in added 
deposit, to block the gas exit from the combustion chamber. The gas exit 
is, perforce, at the end or bottom of the combustion chamber and for at 
least horizontal exit, or exit above the horizontal which is at least at 
90 degrees to the vertical axis of the combustion chamber. The salt 
obstruction problem has, through long experience, been a serious deterrent 
to combustion-disposal of mineral-laden liquids. 
The liquid streams vary widely and may not possess sufficient calorific 
value for self-burning. Burners for admission of the micronized (atomized) 
liquids to the combustion chamber are equipped with means for admission of 
standard fuels along with the liquid streams, to assure burning 
(combustion) as a standard condition. All systems provide for 
uninterrupted burning for calculated periods, which are followed by 
calculated entry of cooling fluids for combustion temperature decrease, in 
a calculated manner and to a calculated degree. However, due to inherent 
difficulty in providing adequate rapid cooling, most of the mineral matter 
remains in the molten state, and as it `wets` any hot surface it strikes 
to run down the combustion chamber walls to the floor (or bottom) of the 
combustion chamber and accumulate as recited. Also, gas-borne molten 
particles are driven by the gases into direct contact with the floor or 
bottom of the combustion chamber. 
SUMMARY OF THE INVENTION 
It is a primary object of this invention to provide an improved 
construction for the combustion chamber of apparatus designed to dispose 
of liquid waste streams, which carry particulate waste and/or chemical 
products of minerals or metals. 
These and other objects are realized and the limitations of the prior art 
are overcome in this invention by providing a specially-designed 
construction for the lower portion of the lower chamber of a conventional 
apparatus for the disposing of liquid waste. 
Such devices are generally constructed with two cylindrical chambers 
positioned coaxially one above the other, with a burner at the top, with 
the fuel and air streams directed downwardly. At some intermediate point 
the waste liquid is micronized (atomized) into extremely small droplets, 
so as to be converted rapidly, in the high temperature atmosphere of the 
combustion chamber into vapor and chemical salts of the minerals. 
Since the streams of flame and products of combustion are directed 
downwardly, most of this mineral material is directed to the bottom of the 
lower chamber. However, if turbulent combustion is provided, there is 
contact with the refractory wall of the chamber and the molten salts can 
flow down the inner wall of the refractory onto the bottom of the chamber. 
The floor of the chamber is positioned just below the outlet through the 
wall of the chamber, for the exit of the products of combustion. Thus, the 
particulate matter collects on the floor and must be removed, in a 
continuous fashion, to avoid building up a deposit of such size as to 
close, or partially close, the passage for the hot products of combustion, 
which would necessitate the stoppage of the combustion process, and 
removal of the solid material. 
The improvements of this invention lie in the construction of the bottom of 
the combustion chamber, which is in the shape of a flat funnel, of 
inverted conical shape, with a drain pipe at the center at the lowest part 
of the floor. A circular annular water channel is provided along the 
inside surface of the wall of the chamber, just above the floor. The 
circular channel can be of round or rectangular cross-section, but has a 
slot or opening at the top of the inner wall. Water is supplied to and 
flows circumferentially in the channel, out through a circumferential gap 
or opening, near the top of the inner wall. The water flows down to the 
floor, and diagonally downwardly toward a center drain at the bottom of 
the funnel. The water flows in a continuous film covering the floor and 
can chemically dissolve or mechanically wash away the particles which have 
been deposited on the top of the conical floor. 
Because of the necessary cross-sectional size of this water channel, the 
bottom end of the refractory lining of the chamber is extended inwardly in 
the form of a flange, so that the inner diameter of the refractory is 
smaller than the diameter of the inner wall of the channel. Thus, molten 
material flowing down the refractory wall will flow over the inner edge of 
the refractory, directly onto the metal floor, and will be washed down by 
the water flowing over the inner wall of the channel.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Referring now to the drawings and, in particular, to FIG. 7, there is 
illustrated schematically, the general construction of a conventional 
combustion system, for combustion disposal of liquid waste streams. Such 
overall construction forms no part of this invention and will not be 
described, other than the lower portion 10, below the plane 2--2 of the 
lower chamber, which is the part which involves this invention. 
Referring now to FIGS. 1 and 2, there is shown to a large scale the lower 
half of the lower chamber indicated generally by the numeral 10. 
The lower combustion chamber comprises a cylindrical steel chamber 20 
having an outlet pipe 26 and flange 28 for attachment of conduit for exit 
of products of combustion, indicated by arrow 23. Numeral 22 indicates a 
refractory lining on the inner wall 20 of the chamber, for the protection 
of the steel from the hot flame, indicated by the arrows 30 moving 
downwardly from the upper chamber into the lower chamber to exit as 
indicated by arrow 23. 
In the upper chamber (not shown, but well-known in the art) the waste 
liquid stream is atomized, or micronized, into very minute droplets, which 
as they enter the hot flame of the burner are evaporated to leave solid 
particles, or molten material, which are carried down with the flame and 
product of combustion indicated by arrows 30, to collect on the bottom 
plate 37 of the chamber. The inner volume of the chamber is indicated 
generally by the numeral 12. 
The bottom, or floor plate 37 of the chamber 20, is formed in an inverted 
conical shape, or flat funnel shape, to provide a sloping wall leading 
down to a center outlet 39. A drain pipe 39 is attached to the floor drain 
to carry away the water stream 38, carrying the solid particulate waste. 
Numeral 16 indicates generally a circular annular channel closed by outer 
plate 16A, bottom plate 16B, inner plate 16C and top plate 16D. The 
channel is closed except for a circumferential slot or gap 14, which is of 
selected width, or vertical extent. While we have illustrated the annular 
channel as having a rectangular cross-section, it will be clear that the 
channel can also be of circular or other cross-section. 
Further details of FIG. 1, and particularly the area circled by the line 
1A--1A are illustrated to greater scale by FIG. 1A. Here the arrangement 
of the cylindrical wall 20 and the support extension 20A, are shown, and 
the relationship of the funnel shaped floor plate 37 welded to the wall 
plate 20, and the positioning of the water channel 16 on top of the floor, 
with the refractory 22 positioned above the water channel 16, having an 
inwardly projecting flange or foot 24, which extends inwardly of the inner 
wall 16C of the water channel by a selected dimension 48. Thus, any molten 
chemical salt deposited on the wall of the refractory 22 will flow down 
that wall onto the sloping portion of the flange 24 and will drop directly 
down onto the floor plate 37 of the chamber, to be washed away. 
Referring now to FIG. 3, there is shown in cross-section a view of FIG. 1 
taken across the horizontal plane 3--3. Here are shown in cross-section 
the outer wall 20 of the chamber, the outer wall 16A of the water channel, 
the inner wall 16C of the inner channel and the bottom plate 16B of the 
water channel, and the tangent entry pipes 42, through which water flows 
inwardly in accordance with the arrows 44. The space inside of the channel 
is indicated by the numeral 35. There is a circularly flowing water stream 
to supply the water level to the inner wall, or weir, which flows down 
over the inside wall 16C onto the floor 37, and flows downwardly along the 
floor, toward the outlet pipe 39, which exits radially from the chamber 
structure. The water flow through exit pipe 39 is shown by arrow 38. 
Referring now to FIGS. 4, 5, and 6, FIG. 4 illustrates a plan view of the 
ring channel 16, which, in addition to having the rectangular 
cross-section of FIG. 5, has at least one pipe, or preferably two pipes, 
42 welded tangentially into the ring, for the entry of water from a 
conventional source, (not shown) flowing inwardly in accordance with arrow 
44. As previously mentioned, the inner wall 16C is vertically shorter than 
the outer wall 16A, so as to provide circumferential opening or gap 14, 
which is supported by welded spacers 46 at selected spacing around the 
inner wall of the ring. The use of the spacers 46 to provide a selected 
dimension of the overflow gap is important, since, in the hot regions of a 
structure, such as this combustion chamber, heat warpage can cause sizable 
changes in the dimension of gaps such as 14. Since a uniformly thick layer 
or film of water is desired, the uniform width of the gap is very 
important. 
It is important that there be sufficient and uniform outflow of liquid from 
the internal space 35, over the inner wall 16C and through the gap 14 as 
shown in FIG. 1. When this water flows onto the bottom plate 37 it covers 
the floor with a uniform film, and will chemically dissolve or 
mechanically remove any particulate matter collecting on the floor 37. 
Since the inner wall is completely circular there will be a uniform 
evenly-divided flow of water onto the plate from the outer portion of the 
floor under the ring 16, down to the center drain with the outlet pipe 39. 
The effluent of water and particulate matter is illustrated by the arrows 
38 which flow to a further treatment or separation point. The chamber wall 
20 extends downwardly 20A and rests on the grade 18 by means of foot 
plates 20B, etc., as is conventional. 
FIG. 5 is a cross-section taken across the radial plane 5--5 of FIG. 4. 
FIG. 6 is an internal view of the ring taken across the plane 6--6 of FIG. 
4. 
What has been described is an improved construction of the lower portion of 
a combustion chamber of a waste disposal unit, of otherwise conventional 
design. The improved construction of the lower end of the lower chamber 
facilitates the continuous removal of the particulate matter which remains 
after the waste stream has been burned and/or evaporated, and disposes of 
it continuously, to avoid any possible accumulation that would affect the 
flow of the products of combustion that flow downwardly through the 
structure, and out of the lower exit portal. 
While the invention has been described with a certain degree of 
particularity, it is manifest that many changes may be made in the details 
of construction and in the arrangement of components. It is understood 
that the invention is not to be limited to the specific embodiments set 
forth herein by way of exemplifying the invention, but the invention is to 
be limited only by the scope of the attached claims, including the full 
range of equivalency to which each element or step thereof is entitled.