A Process for Preventing the Formation of Boiler Incrustations.
Year: 1899

page_text: Date of Application, 26th Jan., 1899-Accepted, 16th Dec.,
1899
COMPLETE SPECIFICATION.
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A Process for Preventing the Formation of Boiler Incrustations.
I, LOUIS EDUARD OTTO DE VISSER, of 60, Singel, Schiedam, in the Kingdom of
Holland, Doctor of Chemistry, 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:-
Whilst the method of treating the feed water for boilers by means of alkaline
depositing re-agents such as hydrate of lime (Clark, 1841) soda and hydrate of lime
(Schulze) caustic soda with or without lime, or lime and chloride of barium
(de Haen) fixed salt and lime (Krohnke) and so forth (Dehne, Duclaux) has long
been known the process forming the subject of this invention is based upon the
special employment of solvents or neutralizing agents such as hydrochloric acid
with or without the addition of sal ammoniac or chloride of barium.
Apart from the varying quantity of free carbonic acid which is contained
in hard water its most marked feature is its alkaline character and for this reason
its use for directly feeding boilers is particularly liable to lead to the formation of
boiler incrustations. None of the known processes, which have been referred
to above in part, has effectually obviated this defect. The best that could be
effected by means of suitable treatment has been to reduce the degree of hardness
to about 4° and even then fur and the like is formed.
Now the present inventor has discovered that hydrochloric acid (or chloride of
ammonium) forms a suitable medium for preventing the formation of incrustation
the respective carbonates being converted into chlorides, and although a deposit
of slime is formed no formation of scale or fur takes place.
The practical carrying into effect of the process consists in determining the
necessary quantity of acid and in the continuous and automatic supply of the
hydrochloric acid or sal ammoniac or a mixture of the two to a suitable quantity
of the water to be treated.
In accordance with the known titration methods the quantity of acid requisite
for the neutralization of a certain description of water may be ascertained by
means of 1/10 test hydrochloric acid or the like and phenolphthalene or the like
as indicator, whilst if sal ammoniac is used the quantity of the salt equivalent
to the acid may likewise be readily ascertained.
The starting points for the use of chloride of barium in the case of water con-
taining much gypsum are generally and specifically known by means of de Haen's
process and it is therefore unnecessary to refer to them.
When the proportion of the addition (which may amount to 1:10000 to 1:100000)
has been determined the apparatus illustrated in the accompanying drawing and
which is automatic in its action may be employed.
Fig. 1 is a front elevation and Fig. 2 an end elevation of the apparatus.
a and b are two water containers, each of which holds say 500 litres. The water
flows through c into b until it overflows through into e. The balance beam f
being thereby depressed the plug v is raised by means of a two-armed lever. The
reservoir 6 is consequently emptied through g into a reservoir arranged beneath the
water meter the steam generator being supplied from such reservoir. In its

page_text: descent the valve z in the bottom of the vessel e is opened by coming into contact
with the fixed bracket t and the contents of the vessel e are thereby discharged,
(into the funnel for example). As soon as the vessel e is raised from the
bracket t, the valve is automatically closed, and the tank receives a fresh charge
through the overflow spout d. As soon as the balance beam has been depressed
the water flows through e into a and so on in succession. This rise and fall of
the balance beam actuates counting mechanism by means of which the apparatus
constitutes a water meter.
The devices for the supply of the acid solution are arranged in front of the
apparatus. The acid solution flows from a wooden vessel through the lead pipe h
and the three-way cock into the small reservoir until the level in the capillary
tube s¹ is equal to that in the wooden vessel.
When the balance beam, descends the three-way cock is turned through
90 degrees and the contents of pl flow through q¹ and the acid solution from p
mixes with the water from a and the acid solution from 2 with the water from b.
a and b are of equal capacity as are likewise P and 21.
The receptacles and p₁ are advantageously formed of tombac (100 parts
copper and 12 parts of tin). The dimensions of the acid receptacle are of course
dependent upon the size of the water meter and also upon the strength of the acid
solution which it is desired to employ and so forth.
The cost of the chemicals employed is very small.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is:
First. A process for the prevention of the formation of boiler incrustations
which consists in the addition of hydrochloric acid or sal ammoniac with or without
the addition of chloride of barium to the water (so as to neutralise its alkaline
properties) by means of an automatic mechanical device for the purpose of pre-
venting the formation of boiler incrustations.
Second. Apparatus for the automatic admixture of a definite quantity of
chemicals to liquids or fluids which consists of two three-way cocks and
reservoirs 21 so connected with a balance beam f that the said reservoirs are
alternately filled from a common source of supply and emptied into separate
vessels, substantially as described with reference to the drawings.
VUO
L. E. O. DE VISSER.
Per W. H. Beck,
115, Cannon Street, London, E.C., Agent.