baltur BT 75 DSNM-D, Инструкция

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20
VARIANTS FOR BURNERS PROVIDED WITH STEAM PRE-HEATER TO HEAT THE FUEL OIL
The burner can be provided with a pre-heater of the fuel oil which operates with steam; the fuel will be heated by steam
and there will be a consequent saving in electricity.
This device consists of a small tank in which steam circulates and inside the tank is a coil in which the fuel oil to be
heated circulates.
This particular device permits a notable reduction in the dimension of the pre-heater.
When the burner starts up, cold fuel oil would be forced to pass through the coil of the steam pre-heater still cold
because it would not yet have been heated by the steam. The high viscosity of the fuel (cold), the notable development
(length) of the coil its relatively small diameter (necessary in order to obtain a high thermal exchange), would determine
a strong pressure loss and consequently the fuel would reach the nozzle at insufficient pressure.
To avoid this situation, the steam pre-heater has been provided with a manual-controlled by-pass which prevents,
when open, the fuel passing through the coil (see BT 8576).
Installation
The user should provide and install on the pipeline that takes the steam to the fuel heater the following: a gate valve,
a suitable pressure reducer (adjustable from 1 to 8 bar) and a control manometer (end of the scale 10 bar).
Do not recuperate the condensate which is discharged from the heater to avoid, in case there is a leak in the coil, fuel
oil going into the steam system.
Regulation
When the boiler has reached sufficient pressure, open the gate valve which allows the steam inflow to reach the oil pre-
heater, and open slightly the “air discharge” gate valve fitted on the condensate outlet pipeline.
While the steam is discharging from the gate valve slightly opened, regulate the pressure reducer at a sufficient value
in order to heat the fuel oil to a temperature a little above (about 10 ÷ 15 °C) that at which the regulation thermostat of
the electric heater has been set. An orientative regulation can be carried out by operating the pressure reducer in
function with the value indicated by the manometer; if necessary, correct the regulation after having controlled the
temperature of the fuel coming out of the steam heater.
Steam Pressure
at manometer bar
1 1,5 2 2,5 3 3,5 4 4,5 5 6 7 8
Approximate
Corresponding
Temperature °C
120 127 133 138 143 147 151 155 158 164 169 174
When regulation has been carried out, close the air discharge gate valve.
The thermostats (minimum and regulation) of the electric pre-heater should be regulate normally as described in
Chapter “Start up and Regulation”.