27
•
In a separate container prepare a solution of 10% water and caustic soda (9 parts water and 1 part caustic
soda). Wash the inside of the generator with the solution and rinse.
•
Lubricate the thread of the cover tie rods with graphitised grease.
•
Close the cover and reassemble the union section of the chimney.
•
Assemble the burner and make the connections correctly.
•
Start the generator with the due precautions to eliminate the humidity absorbed by the refractors.
•
The operation should be performed as follows:
•
Light the burner and leave it lit for about 1 minute; then switch it off and wait 3-4 minutes.
•
Repeat the operation 3 or 4 times.
Generator in vertical version
To extract the coil from the generator proceed as follows:
•
Remove the fuel piping and the electrical connections to the burner and disassemble the front cover.
•
Disassemble the water and steam connection piping and discharge.
•
Unscrew the ring nuts and extract the smoke sealing gaskets.
•
Unscrew the connecting stub pipes using a pipe wrench.
The coil thus freed can be hooked to the eye bolts and taken out of the generator.
The operation can be performed by putting a suitably sized and possibly movable lifting device in position
above the boiler.
In the case of horizontal generators the coil can be hooked to the eye bolts and taken out of the generator on
a suitably strong fork lift truck.
Assembly:
•
Hook the coil, lower it into the generator making sure that the connections coincide with the sleeves and
check the centring of the coil with respect to the plating inside.
•
Replace the front cover sealing gaskets.
•
Assemble the stub pipes packing the conical threads with a little teflon tape and tighten completely.
•
Put new smoke sealing gaskets in the housings leaving them protruding by the sleeves about 5–10 mm.
for later adjustments.
•
Lubricate the threading with graphitised grease and tighten the ring nuts.
•
Lubricate the stud bolts and reassemble the upper cover.
•
Connect the water, steam and discharge piping and make the connections to the burner again.
•
Start the generator and check the seals, adjust if necessary.
INSTRUCTIONS FOR CHEMICAL DESCALING
1. With coil empty: wash the inside with just water by means of the supply pump. (If this operation is made
possible by the general state of the coil, it should last for a few minutes).
2. Immediately afterwards stop the pump and drain.
3. Remove the meshes of the filters before the condensation discharge (in the version with steam separator)
and the water suction pump.
4. Prepare the descaling acid solution in a suitable container (water + commercial hydrochloric acid (HCI
33%) + inhibitor “Lithsolvent”),according to the table specified.
5. Descale the coil putting the acid solution in from the top (steam intake pipe) and recovering it in the col-
lection container draining the solution itself from the supply connection.
The operation of putting in and recovering the descaling solution should be performed with a small pump
which allows the continuous circulation from coil to the tank in closed cycle.
The pump delivery is proportional to the boiler capacity:
E.g.: for a UM 30- about 300 It/h; for UM50- about 500 lt/h etc.
For the unions the PVC hoses available on the market can be used.
