Improvements in or relating to the Smelting of Zinc.
Year: 1892

page_text: Date of Application, 21st Sept., 1892
Complete Specification Left, 21st June, 1893-Accepted, 22nd July, 1893
PROVISIONAL SPECIFICATION.
Improvements in or relating to the Smelting of Zinc.
We, EDWIN Ruck of 9 Lewis Street, St. Thomas, and FREDERICK NEALE
RAGGATT of 157 St. Helen's Avenue, both in Swansea, in the County of
Glamorgan, Accountants, do hereby declare the nature of this invention to be as
follows:-
A considerable percentage of zinc is lost during the smelting process, most of
which issues from the mouths of the pipes or retorts as fumes or oxide of zinc and
not only is lost but the fumes are disagreeable and unhealthy to the workinen.
Our invention is applicable to any kind of smelting furnace, and it consists in
collecting the fumes and subsequently condensing them. For this purpose we
provide the front of the furnace with one or more hoods, the front of which may be
hinged to the upper part of the furnace. The fumes as they issue from the mouths
of the retorts are drawn by the action of a blast, preferably steam, through a
pipe connected with the hood into one or more tanks or other condensing apparatus
where the zinc oxide will be deposited.
If, however, it is found that any zinc oxide passes through the tank or other
condensing apparatus without being precipitated, we may arrange another steam jet
at the outlet so as to force the fumes and gases escaping into another tank containing
water, before being liberated and by this means the greater part of the oxide now
lost will be recovered.
It will be understood that we may modify this arrangement without departing
from the spirit of our invention.
Dated this 21st day of September 1892.
W. P. THOMPSON & BOULT,
Agents for the Applicants.
COMPLETE SPECIFICATION.
Improvements in or relating to the Smelting of Zinc.
We, EDWIN RUCK of Lewis Street, St. Thomas, and FREDERICK NEALE
RAGGATT, of 157 St. Helen's Avenue, both in Swansea, in the County of
Glamorgan, Accountants, do hereby declare the nature of this invention and in
what manner the same is to be performed, to be particularly described and ascertained
in and by the following statement :-
A considerable percentage of zinc is lost during the smelting process, most
of which issues from the pipes or mouths of the retorts as fumes or oxide of zinc
and not only is lost but the fumes are disagreeable and unhealthy to the workmen.
Our invention is applicable to any kind of smelting furnace, and it consists in
collecting the fumes and subsequently condensing them.
For this purpose we
provide the front of the furnace with one or more hoods, the front of which may be
hinged to the upper part of the furnace. The fumes as they issue from the pipes
of the retorts are drawn by the action of a blast, preferably steam, through a pipe
connected with the hood into one or more tanks or other condensing apparatus
where the zinc oxide will be deposited.
If, however, it is found that any zinc oxide passes through the tank or other
condensing apparatus without being precipitated, we may arrange another steam jet
at the outlet so as to force the fumes and gases escaping into another tank containing
water, before being liberated and by, this means the greater part of the oxide now
lost will be recovered.

page_text: It will be understood that we may modify this arrangement without departing
from the spirit of our invention.
In the accompanying drawings
Figure 1 is an elevation of one side of a gas furnace fitted with apparatus constructed
according to our invention, one of the hoods being shown partly in elevation and
partly in vertical section.
Figure 2 is a transverse section on the line 2-2 of Figure 1, the furnace in
this view being shown merely in outline.
Figure 3 is a perspective view of part of Figure 1.
Like letters indicate like parts throughout the drawings.
A is the furnace and A¹ the pipes of the retorts thereof; as these parts constitute
no independent feature of our invention no further description thereof is deemed
necessary.
B are the hoods, the fronts of which though not so represented in the accom-
panying drawings may be hinged so that when desired they may be turned to a
horizontal position or vertically against the pipes C in either of which positions
said fronts could be secured by suitable means. This provision would not generally
be necessary, as the hoods B do not extend down far enough to interfere with the
workmen.
The hoods B are secured to the furnace so that their open ends are immediately
over the retort pipes A'.
D is a pipe with which each of the hoods B is connected by means of a preferably
taper rectangular pipe B¹.
The pipes C are connected each to the upper part of one of the hoods B.
E are hinged valves or dampers provided at the junction of the pipes B¹ with the
hoods B and each of which is provided with a handle or lever E whereby it may
be turned from the position shown in full lines to that shown in dotted lines in
Figure 2, and vice versa; any suitable means, not shown in the drawings, may be
employed for retaining the dampers E or handles E' thereof in the position
corresponding to those shown as regards the dampers in full lines in Figure 2. If
desired the dampers E of two or more of the hoods may be connected so that they
may be operated by the same handle.
The pipes C may each connect directly with the atmosphere or they may all be
connected together before finally discharging into the atmosphere or they may be
connected with a suitable smoke-stack through which the fumes passing through
them will be discharged into the atmosphere.
The pipe D is connected with any suitable condensing chamber or this pipe itself
may be utilized as a condensing chamber by fitting longitudinally within it screens
of canvas, metal or other material, and, at a suitable distance from these screens,
admitting low-pressure steam so as to damp the fumes and thereby cause them to
stick to the screens.
We have found that with a good stack and all the joints of the hoods, pipes &c.
air-tight, the natural draught is sufficient to draw the fumes into the hoods B, and
this is obviously the most economical method of working. The fumes may however
be drawn or forced in by any suitable means, for example they may be drawn in by
a fan or forced in by a steam jet or compressed air.
When the retorts or furnaces are being stirred out considerable dust is produced
and this if allowed to mix with the oxide deposited in the condensing chamber
would greatly deteriorate it. It is for this purpose that we provide the dampers E
and pipes C the former of which during this operation occupy the position shown
in dotted lines in Figure 2 so that these dust-laden fumes are prevented from
entering the pipes BI and instead pass into the pipes C by which they are
discharged into the atmosphere. When however the fumes are considered
sufficiently free from dust the dampers E are turned to the position shown in
full lines in Figure 2 so that said fumes are conducted to the condensing chamber
the course of these fumes on their way to the condensing chamber is indicated
by the arrows in Figure 2.

page_text: The before described apparatus has been found to be of great advantage to
the workmen attending the furnaces for, while the hoods do not allow the fumes to
reach them, they also do not extend out from the furnaces sufficiently to reflect the
heat on to the workmen's heads nor do they allow the fumes to beat back into the
workmen's faces when the metal is being tapped.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
1. Collecting and condensing the fumes escaping from zinc-smelting furnaces
substantially as described.
2. Obtaining oxide of zinc by collecting and condensing the fumes escaping from
zinc-smelting furnaces substantially as described.
3. The combination with a zinc-smelting furnace of a hood and pipe such as B
and B and a condenser directly connected with the hood and pipe substantially as
described and illustrated in the accompanying drawings.
4. The combination with a zinc-smelting furnace and condenser of a hood for
collecting the fumes escaping from the furnace and one or more pipes connected
therewith for conducting the fumes to the condenser substantially as described.
5. The combination with a zinc-smelting furnace and condenser of a hood and
pipe such as B B and C and valve or damper such as E substantially as described
and illustrated in the accompanying drawings.
Dated this 19th day of June 1893.
EDWIN RUCK.
FREDERICK NEALE RAGGATT,
Per E. R.
W. P. Thompson & Boult,
Agents for the Applicants.
EDWIN RUCK.
FREDERICK NEALE RAGGATT,
Per E. R.
W. P. Thompson & Boult,
Agents for the Applicants.