AN IMPROVED METHOD OP. METHODS 07 GENERATING STEAM; AND APPLYING THE SAME TO THE EVAPORATION AND BOILING OF FLUIDS, WHICH METHOD OR METHODS IS OR ARE APPLICABLE TO STEAM ENGINES AND OTHER PURPOSES WECRE STEAM IS OR MAY BE APPLIED
Year: 1838

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
MCCURDY, of Tonbridge Place, New Road, in the County of Middlesex,
Esquire, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Letters Patent under the Great Seal of Great Britain, bearing date at West-
minster, the First day of December, in the second year of Her reign, did,
for Herself, Her heirs and successors, give and grant unto the said John
McCurdy, Her especial licence, full power, sole privilege and authority, that I,
the said John McCurdy, my exors, adññiors, and assigns, or such others as I,
the said John McCurdy, my exors, adñiors, or assigns, shall at any time agree
with, and no others, from time to time and at all times during the term of
years therein expressed, should and lawfully might make, use, exercise, and
vend, within England, Wales, and the Town of Berwick upon Tweed, the
Invention of "AN IMPROVED METHOD OP. METHODS 07 GENERATING STEAM; AND
APPLYING THE SAME TO THE EVAPORATION AND BOILING OF FLUIDS, WHICH METHOD OR
METHODS IS OR ARE APPLICABLE TO STEAM ENGINES AND OTHER PURPOSES WECRE
STEAM IS OR MAY BE APPLIED," partly communicated to me from abroad, and
partly of my own invention; in which said Letters Patent is contained a proviso
that I, the said John McCurdy, shall cause a particular description of the
nature of the said Invention, and in what manner the same is to be performed,

page_text: to be inrolled in Her said Majesty's High Court of Chancery within six
calendar months next and immediately after the date of the said in part recited
Letters Patent, as in and by the same, reference being thereunto had, will
more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
John McCurdy, do hereby declare the nature of the said Invention, and the
manner in which the same is to be performed, are particularly described and
ascertained in and by the Drawings hereunto annexed, and the following
description thereof, and which consists in a new combination of materials, or
the adaptation and application of old and well-known substances to produce or
effect particular purposes, and may be divided into two parts,-first, the
apparatus for the generation of steam, which I term the "circulating steam
generator ;" and, secondly, the form and construction of the pan for the pur-
pose of boiling and evaporation. For the steam generator I construct one or
more flat vessels or chambers, of any given number, length, height, and width,
(proportionate to the size of the engines to be driven or the quantity of steam
wanted,) made of wrought iron or other suitable material. These vessels or
chambers are connected together by pipes or tubes leading from the upper part
or end of one chamber to the upper part or end of the next vessel in succession,
in the whole set through which the steam and water passes. I place these
vessels or chambers, thus arranged, horizontally or vertically in a common
heated furnace in the same manner as a boiler. At the induction end of a set
of apparatus or chambers I attach and connect a small steam engine boiler and
furnace, of sufficient power merely to work a forcing pump or pumps to furnish
a regular supply of water to the whole of the chambers or apparatus. At the
eduction end of the same set of chambers or apparatus I affix an iron box.
(either square or round) having a safety valve upon the top, and two pipes with
cocks or slide valves upon them, one pipe upon the top of the box intended to
convey the steam to the engines or evaporating pans, and the other pipe at the
bottom of the box to let off the waste steam; this lower pipe also serves to
let out any condensed water, or blow out any dirt that may accumulate from
the apparatus.
The outlet or waste pipe is at first kept open and the force
pump set in action; as the water is supplied by the pump it enters into chamber
No 1, and from thence is forced in succession through the remaining chambers
or vessels until it reaches the box, passing over an immense heated surface; a
constant circulation is maintained through the whole of the chambers, and the
steam is generated with amazing rapidity, the quantity bearing an exact pro-
portion to the water injected and the quantity of surface in the chambers
exposed to the action of the fire and water. When it is desirable to heat the

page_text: pans or drive the engines, the valve or cock of the pipe leading to them is
opened, and the cock or valve of the outlet or waste is shut. The pan for
evaporation is constructed of vessels or chambers of a similar construction,
except that the vessels be flat instead of vertical, every two being connected at
the edges by rivets, thus forming a double bottom to the pan, the separate
chambers being united by pipes or connections at the alternate ends, so that a
circulation of steam is kept up from one end of the pan to the other, every
part of the bottom of the pan into which the steam is admitted being thus
exposed to its action.
pan
The has sides around it in the usual form, about two feet high. Under
the very bottom of the pan outside is laid a body of loose sand covered over
with two or three inches of pulverized charcoal, upon which the pan rests; this
acts as a non-conductor of heat downwards, and as it is the nature of coloric to
ascend, every part of the water or other substance in the pans over the steam
in the bottom boils at the same time. A safety valve is also attached to the
last chamber of the last pan (in case several are used) to permit the escape of
the condensed water and steam.
B is the
In the Drawing A, A, represents a set of fourteen steam chambers set hori-
zontally in two furnaces of seven each, numbered from 1 to 14. They are each
intended to be fifteen feet long and two feet high, the water and steam passage
two inches wide in every chamber, and the fire spaces between each two about
four inches. These vessels contain a superficies of nine hundred feet, which,
allowing ten feet per horse power, is about equal to the surface of a boiler of
one hundred horse power, and over the whole of which surface every particie
of water passes in its progress from the forcing pump to the box.
small engine and boiler (of about a one horse power) to work the forcing
pumps for supplying the apparatus with water. C is the box. D is the pipe
and cock leading from the steam apparatus to the engines or pans. E is the
waste pipe and cock. F is the safety valve. a, a, a, are the communications
between each of the two chambers through which the water and steam passes
from one to the other. Braces of iron are also affixed to the ends of the
chambers to preserve them at proper distances from each other; additional
rivets and washers are also put in through the sides of the chambers to
strengthen them and unite the sides to each other. G represents a boiling or
evaporating pan with five chambers, numbered from 1 to 5, each twenty feet
long and two feet, wide, forming a boiling pan of two hundred superficial feet,
with a double or false bottom for containing the steam about two inches deep;
the different chambers are also joined at the alternate ends by pipes or
tubes, thus keeping up a current or circulation of steam under the whole

page_text: surface of the pan. A safety valve is placed upon or at the end of the last
chamber.
I claim as original in the generators and pans the arrangement or combina-
tion of a set of flat vessels or chambers in such a manner, and so connected, as
to produce at all times a perfect circulation of water and steam through them
from one end to the other, with a small engine and boiler at one end to work
the forcing pump to supply them with water, and at the other end a box with
two pipes and valves, fitted in the manner described, to open and shut alter-
nately, by which means the circulation is always maintained. He also claims
as original the combination of similar vessels (but differently disposed) so as to
form the bottom of an evaporating pan, which, although composed of different
chambers at the bottom, offers to the eye.at the top the appearance of a common
pan. The ends of the chambers being united by tubes, also keeps up a circu-
lation of steam under the whole bottom. The safety valve upon the pan
regulates the pressure of the steam, and consequently its temperature.
REMARKS. The advantages of this plan for generating steam over the
common boiler arc,--a great economy of fuel, since the generators, being sur-
rounded by the fire, receive all the benefit of its action; saving in first cost;
the generators, in comparison with boilers, will not occupy more than a tenth
part of the space; the great weights of water in the ordinary boiler is avoided,
the quantity in a set of the chambers at one time being very small, and keep
up by cach successive stroke of the forcing pumps; besides which the generators
will raise steam in about twenty minutes, which upon the old plan required an
hour and a half; and, finally, there is no danger from any collapse of the
vessels, or from explosion. The apparatus is applicable to both high and low
pressure engines, and the pan to boiling salt, sugar, soap, &c. The pipes and
cocks leading from the forcing pumps to the generators and to the water tanks
are omitted in the description, being so well understood by every scientific
person. A separate steam engine and boiler, with its own furnace, is preferred
for the purpose of working the pumps, as being more manageable in regulating
the supply of water to the chambers, and also saves the necessity of a hand
pump in supplying them with water before or as soon as they are heated, pre-
venting any injury from the fire to the chambers. An engine of about one
horse power, or even less, will be found amply sufficient for the purpose.
In witness whereof, I, the said John McCurdy, have hereunto set my
hand and seal, this First day of June, in the year of our Lord One
thousand eight hundred and thirty-nine.
JN° MCCURDY. (L.S.)

page_text: AND BE IT REMEMBERED, that on the First day of June, in the
year of our Lord 1839, the aforesaid John McCurdy came before our said
Lady the Queen in Her Chancery, and acknowledged the Specification afore-
said, and all and every thing therein contained and specified, in form above
written. And also the Specification aforesaid was stamped according to the
tenor of the Statute made for that purpose.