Improved Means for Drying White Lead.
Year: 1898

page_text: Date of Application, 16th Nov., 1898
Complete Specification Left, 15th Aug., 1899-Accepted, 16th Nov., 1899
Improved Means for Drying White Lead.
We, THE EAST FERRY ROAD ENGINEERING WORKS COMPANY, LIMITED, of
Millwall, in the County of London, Engineers, FREDERICK SYDNEY TUCKETT,
Manager of the said Company, of the same address, LOCKE, LANCASTER, and
W. W, & R. JOHNSON & SONS, LIMITED, of 1, Leadenhall Street, in the City of.
London, Lead Manufacturers, and EDWARD MAYOTT JOHNSON, Director of said
Company, of the same address, do hereby declare the nature of this invention to be
as follows:
-
In the manufacture of white lead it has heretofore been usual to drive off the
moisture contained in it by distributing it in a thin layer on a table or tables
heated by means of steam pipes, but this method is open to objection by reason
of the considerable time occupied.
Üne
Now according to this invention the white lead is distributed in thin layers and
is dried by means of dry air caused to pass over and in contact with it. The air
may be heated to a temperature of about 220 degrees Fahrenheit, by being passed
through a suitable stove or regenerator, and is then drawn or forced through a
chamber containing trays or tables on which the white lead is spread.
arrangement of apparatus according to this invention comprises a chamber of
circular form having arranged centrally within it a rotatable shaft on which are
mounted one above another a series of tables on which the white lead to be dried
ia spread. Hot air is led from an air heating apparatus to one side of the chamber
to which it is admitted at or about the level of each table through a series of
apertures. On the opposite side of the chamber is a vertical passage connected
with an uptake for the escape of air. The lower part of the passage may con-
veniently be formed with an outlet through which the dried white lead can be
discharged. The chamber is provided with a series of doors arranged preferably
one above another alongside the vertical passage so as to enable the tables to be
readily charged with layers of moist white lead and to enable it, when dry, to be
readily scraped off and discharged from the chamber through the above mentioned
outlet. The shaft on which the tables are mounted extends through the top and
bottom of the chamber and is mounted in bearings at each end; it is adapted to be
rotated at a suitable speed, through gearing which may be arranged below the
chamber.
Dampers may be provided for regulating the admission and escape of the hot
air to and from the chamber so as to ensure the material on all the tables being
properly dried.

page_text: We, THE EAST FERRY ROAD ENGINEERING WORKS COMPANY, LIMITED, of
Millwall, in the County of London, Engineers, FREDERICK SYDNEY TUCKETT,
Manager of the said Company, LOCKE, LANCASTER, and W. W. & R. JOHNSON &
SONS, LIMITED, of 1, Leadenhall Street, in the City of London, Lead Manufacturers,
and EDWARD MAYOTT JOHNSON, Director of said Company, 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:-
In the manufacture of white lead it has heretofore been usual to drive off the
moisture contained in it by distributing it in a thin layer on a table or tables
heated by means of steam pipes, but this method is open to objection by reason
of the considerable time occupied.
"
In the accompanying drawings there is illustrated an apparatus according to
this invention wherein the white lead is distributed in thin layers upon trays or
tables arranged within a chamber, the drying of the white lead being effected by
means of dry air which is drawn or forced through the said chamber over and in
contact with the white lead.
Fig. 1 is a side view of the apparatus, the left hand portion of the figure being
in elevation and the right hand in section; Fig. 2 is a plan view partly in section ;
and Fig. 3 is a sectional elevation at right angles to Fig. 1. The apparatus
comprises a chamber 1 of circular form having arranged centrally within it a
suitably driven rotary shaft 2 on which are mounted, one above another, a series
of tables 3 on which the white lead to be dried is spread. Hot air is led from
an air heating apparatus 4 such as a stove or regenerator to one side of the chamber
to which it is admitted at or about the level of each table through a series of
apertures 5 each provided with a damper 6 capable of regulation from the
exterior of the apparatus. On the opposite side of the chamber 1 is a vertical
passage 7 connected with an uptake 8 for the escape of air. The air may be heated
to a temperature of about 220 degrees Fahrenheit by being passed through the
heating apparatus 4. The lower part of the passage 7 is formed with an outlet 9
through which the dried white lead can be discharged by means of adjustable
scrapers 10 mounted on rock shafts 11 having exteriorly arranged handles 12
fitted with hooks 12" which can be engaged with suitable pins, links or the like so
as to hold the scrapers clear of the tables until it is required to discharge the
material thereon. The outlet 9 is provided with pivoted doors 9" operated by
external handles and with an air tight closure 9b. The chamber is provided with
a series of doors 13 arranged preferably one above another alongside the vertical
passage 7 so as to enable the tables 3 to be readily charged with layers of moist
white lead; the doors 13 also enable the tables to be readily scraped clear of dry
white lead by means of hand tools, when desired, the white lead being discharged
through the outlet 9.
The shaft 2 on which the tables 3 are mounted extends through glands in the
top and bottom of the chamber and is mounted in bearings 14, and 14ª; the shaft
is adapted to be rotated at a suitable speed through gearing 15, 15 which may be
arranged below the chamber as shown and driven from an electric motor 16.
In addition to the dampers 6 dampers may be provided for regulating the escape
of the hot air from the chamber, so that by regulating the various dampers the
proper drying of the material on all the tables may be ensured.
With apparatus constructed as described, the manufacture of white lead can
be carried out without injury to the workmen employed, as the tables of the

page_text: apparatus having been charged with moist white lead, the apparatus need not be
again opened until the white lead has been dried and discharged into tubs or
other receptacles, thereby avoiding the escape of poisonous dust. Moreover, the
drying can be effected much more rapidly than has heretofore been usual.
In some cases in order to avoid waste of heat by discharging the air at a high
temperature two or more apparatus such as described may be combined and the
hot air may pass from one to the other throughout the series, suitable dampers
or valves being provided in the air conduits for enabling anyone or more of the
apparatus to be cut off from the others for charging, repairing, &c.
In such an
arrangement provision may be made for treating the wettest material with air
which has passed over the moist material.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed we declare that what
we claim is:-
1. Improved apparatus for drying white lead wherein a series of rotary
horizontal tables adapted to receive layers of white lead are mounted one above
another upon a shaft within a chamber supplied with dry air through a series of
apertures fitted with dampers one or more of which is or are arranged at or about
the level of each table, said chamber having an air discharge passage and an
aperture through which the dried white lead will fall as it is scraped from the
rotating tables, substantially as described.
2. The improved apparatus for drying white lead constructed, arranged and
operating as described with reference to and shown in the accompanying drawings.
Dated this 16th day of August, 1899.
Www Both way 01 August, 1899.
For the Applicants,
W. LLOYD WISE,
46, Lincoln's Inn Fields, London, W.C., Chartered Patent Agent.