CERTAIN IMPROVEMENTS IN PREVENTING AND REMOVING INCRUSTATION IN STEAM BOILERS AND STEAM GENERATORS
Year: 1844

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, LOUIS
ANTOINE RITTERBANDT, of Gerard Street, Soho, in the County of Middlesex,
Doctor of Medicine, 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 Second day of December, in the eighth year of Her reign, did,
for Herself, Her heirs and successors, give and grant unto me, the said
Louis Antoine Ritterbandt, my exors, adñiors, and assigns, Her especial
licence, full power, sole privilege and authority, that I, the said Louis Antoine
Ritterbandt, my exors, adiñors, and assigns, or such others as I, the said
Louis Antoine Ritterbandt, my exors, adññiors, or assigns, should at any
time agree with, and no others, from time to time and at all times thereafter
during the term of years therein expressed, should and lawfully might
make, use, exercise, and vend, within that part of Her said Majesty's United
Kingdom of Great Britain and Ireland called England, Her Dominion of
Wales, the Town of Berwick-upon-Tweed, the Islands of Guernsey, Jersey,
Alderney, Sark, and Man, and also in all Her Majesty's Colonies and Planta-
tions abroad, my Invention of "CERTAIN IMPROVEMENTS IN PREVENTING AND
REMOVING INCRUSTATION IN STEAM BOILERS AND STEAM GENERATORS;" in which
said Letters Patent there is contained a proviso that I, the said Louis Antoine
Ritterbandt, shall cause a particular description of the nature of my said
Invention, and in what manner the same is to be performed, under my hand

page_text: and seal, to be inrolled in Her 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 the nature of the said Invention, and in what manner
the same is to be performed, are particularly described and ascertained in
and by the following statement, that is to say :-
The incrustation of steam boilers and steam generators when fresh water is
used arises chiefly from the heat employed to generate steam, causing the lime
which exists in the water in the form of a soluble bicarbonate of lime to be
converted into an insoluble carbonate of lime, the particles of which as they
fall towards the bottom carry 'down with them masses of other insoluble
matters which may be floating in the water. And when salt or sea water is
employed, as in marine boilers, incrustation is generally promoted by the
carbonate of lime set free by the heat, which as it floats in the water previous
to subsidence forms nuclei, for the accrescence of other matter, and disposes
the saline compounds, such as the sulphate of magnesia, chloride of sodium, &c.,
to crystalize and precipitate much sooner than they otherwise would. Now,
the nature of my Invention consists, in the former case, either in preventing
the formation of carbonate of lime, or in converting it when' formed into a
soluble salt, and in the latter in retarding the formation of the saline crystals,
and thereby also retarding the precipitation of other floating matters which
would produce incrustation. Thus in both cases the waste of heat and
destruction of the metal ordinarily arising from incrustation, and from the
frequent blowing off which is had recourse to, is, in great measure, obviated.
The manner in which I effect these objects I will now proceed to explain.
Although when lime exists in the state of a bicarbonate it is perfectly soluble,
but easily converted by heat into an insoluble carbonate, and so precipitated,
yet there are other salts or forms of lime which remain in solution as long as
the water is not over saturated with them and remains in a heated state.
Among these soluble salts are the hydrochlorate or muriate of lime, or as it is
sometimes also called the chloride of calcium, also the acetate of lime, and the
nitrate of lime. By converting, therefore, the insoluble carbonate of lime
either into a muriate or acetate or nitrate or other soluble salt of lime, it
assumes a condition in which it is not precipitated by the heat, and neither
incrusts the boiler itself nor contributes to its incrustation by promoting the
crystalization or precipitation of other matters. To effect this conversion, I
introduce into the water in the steam boiler or steam generator, or into the
supply tank connected with it, some ammoniacal salt, the acid of which, uniting

page_text: with lime as a base, will form a perfectly soluble salt of lime, not decomposed
or separated by heat. The ammoniacal salt thus to be employed may be either
the muriate of ammonia (called sometimes the hydrochlorate of ammonia, also
chloride of ammonium, and commonly known by the name of sal ammoniac), or
the acetate of ammonia, or the nitrate of ammonia, or any other ammoniacal
salt whose acid forms with lime a soluble compound. I prefer the muriate of
ammonia because of its cheapness, it being easily obtained from various animal
and mineral substances existing in great abundance. It is not necessary to
employ this salt in a state of purity, the inferior crystals before purification and
sublimation serving sufficiently well the purpose of my Invention. The
quantity of the ammoniacal salt to be employed will depend on the quantity of
lime contained in the water in the form of bicarbonate. This can be readily
ascertained by chemical analysis, and I would recommend the following plan
for the purpose, as from its simplicity it can be practised by any working
engineer: Take a gallon or any other measure of the water to be examined,
and evaporate it slowly in an open vessel; collect the solid matter left at the
bottom of the vessel and weigh it carefully; then add to it, in a glass vessel, a
mixture of equal parts of muriatic acid and distilled or rain water, and let it
remain during fifteen minutes; next, filter through white filtering or blotting
paper, or strain through clean linen or calico; collect the solid matter left in
the filter and dry it.; the difference between its weight now and before will
give the amount of carbonate of lime dissolved in the muriatic acid. Thus, if
a gallon of water gives ten grains of solid matter, and after digesting with
muriatic acid there are only six grains left, the gallon contains four grains of
carbonate, of lime. Having thus determined the quantity of lime in a gallon
of water, I would recommend the muriate of ammonia to be used in the same
quantity, or rather a little in excess, as at the rate of fifty-four of this ammo-
niacal salt to fifty of the carbonate of. lime... If the acetate of ammonia be
employed for the purpose of my Invention, the proportions must be about forty
parts of the saturated solution to about fifteen parts of carbonate of lime.
What I mean by saturated solution.is, one prepared by adding carbonate of
ammonia to acetic or pyroligneous acid.or. to distilled vinegar until no more is
dissolved. If nitrate of ammonia.be employed, the proportions must be eighty
parts of the crystals to fifty parts of carbonate of lime. Of course, in every
case the amount of water evaporated in a given time must be taken into
account,, as in proportion to the water evaporated will be the carbonate of lime
set free, and the quantity of the ammoniacal salt required. The action of the
muriate of ammonia (which, for the reason before given, I prefer) is partly

page_text: chemical and partly mechanical; first, it is chemical inasmuch as, after the
introduction of the salt into the water, a double decomposition takes place;
the muriatic acid combines by elective affinity with the lime to form muriate
of lime, while the carbonic acid passes to the ammonia, and forms carbonate of
ammonia; the former, or the muriate of lime, remaining in a state of solution,
and the latter, or the carbonate of ammonia, volatilizing under the influence of
the heat, and passing off along with the steam. This decomposition, however,
goes on slowly and gradually. When the salt is added in considerable quan-
tities at a time, it remains in part in the state of muriate of ammonia until
fresh supplies of water, containing additional quantities of carbonate of lime to
be decomposed, are introduced. In practice, therefore, it will be found of
great advantage so to use the muriate of ammonia, that is, to add it to the
water in considerable quantities at a time, since in this way one application
may suffice for several days or even weeks; this, however, will depend on the
quantity of carbonate of lime in the water and the rate of evaporation. The
mechanical action of this salt (as also of the acetate or nitrate or other salts of
ammonia, as before stated), consists in its increasing the density of the water
(without, however, affecting its clearness), and thus assisting to retain in a
state of suspension any foreign matter which would otherwise sink to the
bottom, and there form a solid incrustation. In case of fixed boilers the salt
is conveniently supplied through the man-hole, or injected in a state of solution.
In locomotive boilers the material may be placed in the tank, and must be
renewed according to the amount of water evaporated per diem and the lime
present in the water. When it is required to free steam boilers or steam
generators from old incrustation, I use the muriate of ammonia, or any of the
ammoniacal salts (whose acids will, with lime as a base, form soluble com-
pounds), in much larger quantities, say, double, or even treble the proportion
described, when the salt is employed for preventing only; and when the old
incrustation is difficult to remove by these means, and does not readily yield to
them, besides the ordinary proportion of ammoniacal salt before described,
I pour once a week into the boiler or supply tank, which has previously been
filled with water, a quantity of muriatic or nitric acid (but I prefer the former)
in the proportion of about one quart to one hundred gallons of water; or if the
acetic acid be used, in the proportion of about one gallon to one hundred gallons
of water; or if common vinegar be employed, in the proportion of about two
gallons to one hundred gallons of water, renewing the operation once a week
until the incrustation is removed. When these ingredients are introduced into
the boiler it is advisable that the engine should be off work.

page_text: And having now described the nature of my said Invention, and in what
manner the same is to be performed, I declare that what I claim is,-
First, the application of ammoniacal salts, in the manner before described,
to prevent and remove incrustation in steam boilers and steam generators; and
Secondly, the use of ammoniacal salts in conjunction with muriatic, acetic, or
nitric acid for the purpose of removing old incrustation, in the manner above
described.
In witness whereof, I have hereunto set my hand and seal, this Tenth