baltur SPARKGAS 3,6 P Betriebsanleitung Seite 33

We think it would be useful to inform you on a few points regarding use of liquid propane gas (L.P.G.).
1) Approximate evaluation of running costs
3
a) 1 m of liquid gas in gaseous state has heating power inferior by about 22.000 Kcal.
3
b) to obtain 1 m of gas about 2 Kg of liquid gas are required. This is equal to about 4 litres of liquid gas.
According to the above, it can be deduced that by using liquid gas (L.P.G.) the following approximate equivalence
is obtained:
22.000 Kcal = 1 m
can be calculated.
2) Safety measures
Liquid gas (L.P.G.) has, in it gaseous state, a specific gravity superior to that of air (specific gravity of propane gas in
relation to air = 1,56) and therefore does not disperse in air like natural gas, which has a lower specific gravity
(specific gravity of natural gas in relation to air = 0,60), but precipitates and spreads at ground level as if it were a
liquid. In view of the above principle, the Ministero dell'Interno ( Home Office) has set limitations for use of Liquid Gas
in circular n° 412/4183 of 6 February 1975. We will look into the points we think most important:
a) Liquid Gas (L.P.G.) for burners and/or boilers can only be used in rooms above ground and overlooking open
spaces. Installations using liquid gas in basements or cellars are not permitted.
b) Rooms where liquid gas is used must have ventilation inlets without closing devices, located on external walls
with a surface of at least 1/15 of the room's area and a minimum of 0,5 m
At least one third of the entire surface of these inlets must be located in the lower part of the external wall, flush
with the floor.
3) Requirements for liquid gas plant to ensure correct operation and safety
Natural gasification, from cylinder unit or tank, can only be used for low power plant. Supply capacity at gaseous
stage, depending on tank dimensions and minimum external temperature, is shown in the following table but only as
a rough guide.
Minimum
temperature
Tank 990 l.
Tank 3000 l.
Tank 5000 l.
With the exception of low power plant, for correct operation and safety, it is always essential to install a suitable liquid
gas heater (vaporiser) immediately in front of the pressure reducer. The vaporiser is a container built in accordance
with Regulations. It has a control thermostat which heats liquid gas by means of an electric resistor or circulation of
hot fluid. Reduction of pressure and change of state (from liquid to gas) considerably lowers temperature. In the cold
season, the latter easily reaches values of much less than zero degrees.
Any humidity (water) by change present in the liquid gas would change into ice and thus impede correct operation of
the reducer (blocked in open position)with consequences that can easily be imagined.
The vaporiser must be installed very near to the reducer to avoid already cooled gas, picked up in liquid form from the
tank, reaching the reducer.
Without the vaporiser, it is practically impossible to ensure correct supply of gas in gaseous state in the cold season.
Pressure reduction can be carried out by means of a suitable pressure reducer.
Widespread use is also made of plant with two-stage pressure reduction because:
a) it reduces risks of freezing and condensation
b) Pipe diameter between the first and second reducers can be less than that required for single stage reduction.
Considerable cost saving can be achieved for large scale networks.
c) Final pressure value is more constant.
NOTES ON USE OF PROPANE (L.P.G.)
3 (in gaseous state) = 2 Kg of L.P.G. (liquid) = 4 litres L.P.G. (liquid). From this, running costs
- 15 °C - 10 °C
1,6 Kg/h 2,5 Kg/h
2,5 Kg/h 4,5 Kg/h
4 Kg/h 6,5 Kg/h
2
- 5 °C - 0 °C
3,5 Kg/h 8 Kg/h
6,5 Kg/h 9 Kg/h
11,5 Kg/h 16 Kg/h
33
.
+ 5 °C
10 Kg/h
12 Kg/h
21 Kg/h