IMPROVEMENTS IN PURIFYING PARAFFIN, AND IN APPARATUS THEREFOR
Year: 1879

page_text: LETTERS PATENT to John Calderwood, Manager of the Addiewell Chemical
Works, West Calder, in the County of Mid Lothian, North Britain, for the
Invention of "IMPROVEMENTS IN PURIFYING PARAFFIN, AND IN APPARATUS
THEREFOR."
PROVISIONAL SPECIFICATION left by the said John Calderwood at the
Office of the Commissioners of Patents on the 22nd May 1879.
JOHN CALDERWOOD, Manager of the Addiewell Chemical Works, West Calder, in.
the County of Mid Lothian, North Britain. "IMPROVEMENTS IN PURIFYING
PARAFFIN, AND IN APPARATUS THEREFOR."
This Invention has for its object the purifying of paraffin in a more effective and
economical manner than heretofore. The Invention consists in subjecting the
paraffin to the joint action of pressure and heat, and also comprises apparatus
specially designed for carrying out the process.
The apparatus consists of an hydraulic press enclosed in a chamber constructed
or fitted so that a suitable heat can be maintained in it in a sufficiently equal and
uniform manner.
The press may be arranged to have a horizontal or vertical or
other movement, but the horizontal movement is preferred, the press being furnished
with a number of vertical plates which are perforated. The perforated plates are ·
in pairs, the two plates of each pair being kept apart by distance pieces or ribs
placed vertically so as to form vertical passages for the descent of the liquid passing
through the perforations and for the circulation of the heated air so as to equalise
the temperature throughout the plates. The cakes of paraffin to be operated on are
placed in the alternate spaces between the perforated plates where there are no ribs
or distance pieces.
The chamber may be heated by means of steam or hot water or other heated
fluid passed through pipes in the chamber or through spaces in the walls or through
both pipes and wall spaces, or a current of heated air may be led through the
chamber or through the tubes.
The paraffin to be purified is prepared in the usual way by being poured in a
melted state into shallow moulds. When cold the cakes are wrapped in canvas or

page_text: other suitable cloth and placed in the press, the temperature in the press chamber
being raised to a suitable degree corresponding to the melting point of the paraffin
operated on and also dependent on the degree of purification desired in each
case.
When the paraffin to be pressed has naphtha or volatile oil mixed with it, the
press chamber should be connected with a condenser or scrubbing column in order
to recover any volatilised naphtha or oil.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Calderwood in the Great Seal Patent Office on the 20th
November 1879.
JOHN CALDERWOOD, Manager of the Addiewell Chemical Works, West Calder,
in the County of Mid Lothian, North Britain. "IMPROVEMENTS IN PURIFYING
PARAFFIN, AND IN APPARATUS THEREFOR."
My said Invention has for its object the purifying of paraffin in a more effective
and economical manner than heretofore, and it consists in subjecting the paraffin to
the joint action of pressure and heat, and also comprises apparatus specially designed
for carrying out the process.
The apparatus consists of an hydraulic press acting in a chamber constructed or
fitted so that a suitable heat can be maintained in it in a sufficiently equal and
uniform manner. The press may be arranged to have a horizontal or vertical or
other movement, but I prefer the horizontal movement, the press being furnished
with a number of vertical plates which are perforated. The perforated plates are
arranged in pairs and the cakes of paraffin are arranged alternately with the pairs
of plates, the expressed liquid escaping through the perforations into spaces between
the two plates of each pair and thence into a bottom receptacle or gutter.
The chamber may be heated by means of steam or hot water or other heated fluid
passed through pipes in the chamber or through both pipes and wall spaces, or a
current of heated air may be led through the chamber or through the pipes.
The paraffin to be purified is prepared in the usual way by being poured in a
melted state into shallow moulds. When cold the cakes are wrapped in canvas or
other suitable cloth and placed in the press, the temperature in the press chamber
being raised to a suitable degree corresponding to the melting point of the paraffin
operated on, and also dependent on the degree of purification desired in each case.
In practice I find that satisfactory results are obtainable when a temperature of
from 15 to 25 degrees Fahrenheit below the melting point of the paraffin is main-
tained in the press chamber.
When the paraffin to be pressed has naptha or volatile oil mixed with it the press
chamber may be connected with a condenser or scrubbing column in order to recover
any volatilised naphtha or oil.
And in order that my said Invention and the manner of performing the same

page_text: may be properly understood I hereunto append two Sheets of explanatory Drawings,
to be hereinafter referred to and representing a practically successful modification
of apparatus for carrying out my process for purifying paraffin. In these Drawings
the same reference numerals are used to mark the same or like parts wherever they
are repeated.
Figures 1 and 2 on Sheet 1 of the accompanying Drawings are a sectional plan
and a sectional side elevation of the apparatus with parts supposed to be broken away
in order to reduce the length of the Figures; Figures 3 and 4 on Sheet 2 are an end
elevation and a transverse vertical section; Figures 5 and 6 are a face view and
horizontal section of a perforated plate; Figure 7 is a vertical section as across
three pairs of plates and shows the mode of holding the cakes of paraffin between
the plates; and Figures 8 and 9 are a face view and horizontal section of another
perforated plate, each pair of plates being composed of plates of each of the kinds
shown in Figures 5 and 8.
In the modification shown in the Drawings the hydraulic press is horizontal, the
cylinder 9 being at one end and connected in the ordinary way by four rods or
tension bars 10 to the stationary head 11 at the other end. The follower or platen
12 fitted on the end of the ram 13 moves between the bars 10, being partly
supported and guided by lugs 14 formed at its upper corners and moving along
upon the two upper bars 10. The space between the cylinder 9 and press head 11
is enclosed by a casing 15, 16, 17, of wood (or it might be any other suitable
material), such casing forming a chamber which is somewhat wider and higher than
the space occupied by the press details. Along the bottoms of the sides of the
chamber a number of connected pipes 18 are fitted and have steam supplied to
them by small pipes 19, whilst larger outlet pipes 20 are provided, the steam being
employed to heat the interior of the chamber and act on the paraffin whilst it is
being pressed as hereinbefore explained. The middle part of the top 17 of the
chamber, that is the part directly over the press space, is composed of a number of
doors 21 fitted to slide in different grooves and giving complete access to every part
for introducing or removing the cakes of paraffin or for other purposes.
A few perforated plates are shown in position at 22 in Figure 1, close to the
press follower 12, but their form and arrangement will be best understood from
Figures 5 to 9, which are drawn to a larger scale. The plates are in pairs and one
of each pair is a plain perforated plate such as is shown in Figures 8 and 9, whilst
the other is made with vertical ribs as shown in Figures 5 and 6, the parts between
the ribs being perforated. In Figure 7 three pairs of the plates are shown together
with two cakes 23 of paraffin. The cakes 23 formed as hereinbefore described and
wrapped in cloth are suspended in position between the pairs of plates each by
a double fold of cloth which has metal hooks 24 attached to its upper edges
to hang on the top edges of the plates on each side. The plates are kept in
position and guided as they are moved along by the press action by means of
notches 25 formed in their lateral edges at the level of the two upper press
bars 10, and guide rails 26 (Figure 4) are fitted to those bars for the notched
parts of the plates to slide upon. At the bottom of the chamber an iron dish
or broad gutter 27 is placed to receive the oil or liquid which being made to
exude from the paraffin cakes by the joint action of the heat and pressure passes
through the canvas wrappings and hanging sheets and through the perforations in
the plates into the vertical channels formed between the plates of each pair by the
interposition of the narrow vertical ribs or distance pieces. The liquid thus collected
by the dish or gutter 27 passes off by a pipe 28.
After each operation and when the exhaust valve of the hydraulic cylinder 9 is
opened the follower or platen 12 is drawn back by a pair of chains 29 passing
over pulleys 30 to a weight or weights 31. The press bars 10 are at about the
middle of their length braced and supported by side castings 32 connected by
upper and lower horizontal tie bolts, and these castings 32 also afford an interine-
diate support to longitudinal bearers which carry the top 17 of the chamber
casing.

page_text: Having thus particularly described my said Invention and the manner of per-
forming the same, I have to state that I do not restrict myself to the precise
details herein described or delineated, but that what I believe to be novel and
original and claim as the Invention secured to me by and in terms of the herein-
before in part recited Letters Patent is,--
1. The purifying of solid paraffin by subjecting the same to the joint action of
pressure and heat, substantially as hereinbefore described.
2. The arranging or combining together of hydraulic pressing apparatus with a
casing or chamber and means for heating such chamber, substantially as and for
the purposes herein before described.
3. The arrangement consisting of the pairs of perforated and ribbed plates,
substantially as and for the purposes herein before described.
In witness whereof, I, the said John Calderwood, have hereunto set my
hand and seal, this Eighteenth day of November, in the year of our
Lord One thousand eight hundred and seventy-nine.
Witness,
EDMUND HUNT,
Patent Agent,
Glasgow.
JOHN CALDERWOOD. (L.S.)