Improvements in Steam Heating Apparatus.
Year: 1895

page_text: Date of Application, 13th Dec., 1891-Accepted, 25th Jan., 1896
COMPLETE SPECIFICATION.
Improvements in Steam Heating Apparatus.
I OTTOCAR LINDEMANN, Engineer, of 53 Victoria Street, Westminster, in the
County of London, 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 :-
My invention has for its object to control and regulate the heat given off by the
coils or radiators of steam heating apparatus with certainty and in accordance with
the requirements.
A steam heating apparatus according to this invention comprises a steam
generator or boiler from which steam is carried by pipes to the heating surfaces
distributed over the building in the form of coils or radiators; the heat transmitted
being controlled by varying the quantity of steam passing into such coils or
radiators. The condensed water is usually carried directly or indirectly back to
the boiler. To cusure exact regulation of the heat transmitted from each heating
surface a permanent steady pressure must be maintained in the steam supply
piping, a constant counter-pressure in the heating coils, and the area of the steam
admission to each coil must be adjusted so that the volume of steam passing into
the coil exactly replaces the volume condensed.
A constant steain pressure and counter-pressure ensure that with any particular
area of opening for steam admission to each coil a fixed quantity of steam will
pass into the heating coils, and in consequence the amount of heat transmitted
through such coils will be constant.
To obtain a steady pressure in the heating coils, independently of the boiler
pressure, a pressure regulating apparatus is arranged in the steam supply piping
between the boiler and heating coils and is so constructed that a constant pressure
is maintained equal to that of a column of water of a definite height.
This is effected by means of an open ended water manometer, one end being
exposed to the constant pressure and carrying a float connected to the steam inlet
valve so that as the float rises the inlet valve is opened, and the other end having
an outlet at such height above the normal float level that a column of water of the
same height would give the desired pressure.
To maintain as nearly as possible a fixed counter pressure in the heating coils
whilst preventing access of air, the air contained in the lower part of the heating
coil is subjected to the pressure of a column of water whose height varies only
very slightly with any displacement of said air to give an increased or diminished
condensing surface in the coil for the steam. This is effected by connecting the
lower end of the coil to the lower end of an open ended water manometer having
enlargements at its ends. If the pressure in the coil should increase, the air in its
lower part is forced towards the lower enlargement of the manometer and gives an
increased condensing surface to the heating coil; the enlargements of the
manometer ensure that for any likely displacement of air the variation in height
of the water column will be very small. The condensed water from the coil may
pass back to the water space of the boiler through a pipe having such a height
that the pressure in the boiler will not force the water from the boiler over it.
In order to adjust the supply of steam to the heating coil a removable disc on
the valve is arranged to fill up the steam passage to the valve and the area of a
groove or grooves in the valve determines the area of the steam passage to the
valve.

page_text: In the accompanying sheet of drawings;
Figs. 1 and 2 are diagramatic views showing slightly modified arrangements for
maintaining a constant pressure in the steam supply pipe:
Figs. 3 and 4 are diagramatic views showing slightly modified arrangements for
maintaining a constant counter pressure in the heating coils, and
Fig. 5 is a section of a valve whose inlet area can readily be adjusted to the
required consumption of steam.
A lower or float vessel E connected through the valve B3 with the steam supply
pipe A from the boiler, is connected at the bottom by a syphon pipe G to a second
or upper vessel H placed at a determined height above it. This upper vessel is
provided at the top with an overflow pipe J. In the lower vessel is a float D
connected by levers C with the steam inlet valve B so that the rising of the float
opens and the falling of the float closes this valve. The float sinks when the water
is forced out of the lower vessel E into the upper vessel H by any increase of
steam pressure due to excess of steam, and the float rises when water runs back
from the upper to the lower vessel owing to fall of pressure due to under supply
of steam. A wider opening of the steam valve is therefore brought about by
under supply of steam, and a closing of the valve by over-supply. The height of
the upper vessel H relatively to the lower E determines the length of the water
column against which the water from the lower vessel must discharge, and so fixes the
pressure at which the steam is maintained in this lower steam vessel. Any excess
of water above the normal collecting in the lower steam vessel is carried away by
the overflow J from the upper vessel H. A pipe F leads from the upper part of
the vessel E to the heating coils.
The action of the apparatus is as follows:-Steam being shut off from the float
vessel E there is no pressure in this vessel, and it stands full of water; the
upper vessel H is empty; the float D is at its top position and the valve B is full
open. If steam be now turned on, a pressure is formed in the vessel E corresponding
to the amount of steam entering relatively to that passing away through the
pipe F to the heating coils. As soon as this pressure is greater than that
represented by the height of the pipe G the water is forced into the vessel H,
the water level in the vessel E is lowered and the steam inlet valve B is in
consequence partly closed. This movement can continue until the water level is
so low that the valve is quite closed, and the vessel H filled with water, any excess
flowing away through J. It follows from this action that the pressure in the
steam vessel E cannot rise higher than that represented by the height of the water
column and also that the pressure cannot fall lower than this when there is a
sufficiency of high-pressure steam supplied from the boiler.
In the modification shown in Fig. 2, there are two steam inlets A and A¹ so.
that under given circumstances separate steam supplies at different pressures may
be used and be arranged so that the low pressure valve opens before the high
pressure. The float D is not directly connected to the levers C and C₁ but
acts on these by the lugs V and V. The levers open the valves, whilst the closing
is effected automatically. When the float rises, valve B is first lifted, and this
being full open a further rising of the float opens B. The valves close in the
reverse order when the float sinks. The application of this modified apparatus is
advantageous where exhaust steam from an engine, supplemented by live steam
is used for heating.
To maintain as far as possible a fixed counter pressure in the heating coils, and
at the same time to entirely or nearly entirely prevent air from the outside passing
into the heating apparatus, all the heating coils O are connected by one or more
pipes R to a closed vessel S which is joined by a syphon pipe T to a second
vessel U placed at higher level and provided with an outlet to the atmosphere.
The lower vessel S is at first filled with water and the upper contains air. When
the heating apparatus is in use, and steam is admitted to the heating coils, the air
contained in these coils is displaced by the steam. This air passes into the lower
vessel S and displaces and forces out of this an equivalent volume of water

page_text: into the upper vessel. The permanent difference of level between these two
vessels fixes the height of the water column which determines the counter pressure.
in the coils when these are in use.
The steam inlet P to the heating coils may be either at the top or in other
position. If at the top the steam displaces the air without mixing with it, the
upper part of the coil which contains steam will have the full temperature due to
this, whilst the lower part which contains only air, will have only the same
temperature as the room in which the coil is placed. If the steam be admitted at
the bottom or side of the heating coils, the steam mixes with the air and the whole.
of the coil will be more or less warmed to the same temperature.
The action of the complete arrangement is as follows:-
The valve P being closed, the heating coil O is filled with air the vessel S is.
nearly filled with water, and the bottom of the vessel U is just covered with water.
The air in the heating coil is thus under a pressure equivalent to the height of the
water column Z, and this is approximately the difference between the levels of
the two vessels S and U. When valve P is opened steam passes into the coil and
forces part of the air contained therein into the vessel S from which an equivalent
volume of water is displaced and pressed into the upper vessel U. The condensing
surface of the coil is thus increased until it is sufficient to condense all the steam
passing into the coil. According to the quantity of steam admitted the volume of
displaced air and water is greater or smaller, but as the difference of level of the
water in the two vessels S and U remains approximately constant, the variation of
the pressure in the coil O is very small. Any number of coils may be connected
to the vessels S and U by one or more air pipes.
In the modification shown in Fig. 4 an air pipe M is connected to the vessel S.
with opening at the bottom of this vessel, so that after the air from the coils has
entirely displaced the water in the vessel S the end of the pipe is unsealed, and
any further air may escape direct to the atmosphere. The pipe M also serves to-
allow air from the outside to pass into the coils when these are shut off, so soon as
the condensation of the steam has produced a partial vacuum.
For adjusting the supply of steam to meet the various requirements of the
different heating coils, the underside of the steam inlet valves to the coils is.
provided with a disc R which closes the steam passage through these valves. The
discs have on their outer surface one or more grooves S through which the steam
can pass when the valve is opened, and in each case, a disc is chosen with a groove
or grooves of such size, that with the valve full open, and under the arranged
difference of pressure between the steam in the supply pipe and in the coils, just
enough steam is admitted to displace all the air from the coils, and to replace the
volume of steam condensed.
With this arrangement, any particular opening of the steam supply valves on
any of the coils will ensure a proportionate transmission of heat and the regulation
is thus rendered as easy as possible for the attendant.
Having now particularly described and ascertained the nature of my said inven--
tion and in what manner the same is to be performed, I declare that what I
claim is:-
1. In connection with steam heating apparatus in which a steam boiler supplies
steam to heating coils or radiators a steam pressure regulating apparatus consisting
of an open ended water manometer, one end being exposed to a constant pressure
and carrying a float connected to the steam inlet so that as the float rises the inlet
valve is opened, and the other end having an outlet at such height above the normal
float level that a column of water of the same height would give the desired
pressure.
2. In connection with steam beating apparatus in which a steam boiler supplies
steam to heating coils or radiators a steam pressure regulating apparatus consisting
of a lower vessel provided with a steam inlet valve operated by a float in such
vessel, and of an upper vessel connected at its bottom to the bottom of the lower

page_text: vessel so that by the partial filling of this upper vessel with water from the lower
vessel, by the pressure of the steam in same, the float will change position, and by
acting upon the opening of the steam valve maintain an approximately constant
pressure of steam in the lower vessel.
3. In connection with steam heating apparatus in which a steam boiler supplies
steam to heating coils or radiators a steam pressure regulating apparatus consisting
of an open ended water manometer connected at its lower end to the lower end of
the coil and having enlargements at its ends.
4. In connection with a steam heating apparatus in which a steam boiler supplies
steam to heating coils or radiators the counter pressure regulating apparatus for the
coils or regulators consisting of an upper vessel and a lower vessel both partly filled
with water and air, the lower vessel being connected by pipes to the heating coils
and the bottoms of the two vessels being joined together by a syphon pipe.
5. In connection with steam heating apparatus in which a steam boiler supplies
steam to heating coils or radiators, the valve with adjustable opening for steam
admission consisting of a stop valve and a removable disc on the valve filling up
the steam passage of same, and having a groove or grooves in its periphery of the
required area for the passage of the steam.
Dated this 12th day of December 1895.
WHEATLEY & MACKENZIE,
40 Chancery Lane, London, W.C., Agents.