Unigas PBY510, Руководство по установке, использованию и обслуживанию

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C.I.B. UNIGAS - M03993CH
14
Pipe heating system
Pipe heating system must be provided, that is a system to heat pipes and plant components to mantain the viscosity in the pumping lim-
its. Higher the oil viscosity and lower the ambient temperature, more necessary the pipe heating system.
Inlet minimum pressure of the pump (both for supplying system and burner)
A very low pressure leads to cavitation (signalled by its peculiar noise): the pump manifacturer declares the minimum value. Therefore,
check the pump technical sheets.
By increasing the oil temperature, also the minimum inlet pressure at the pump must increase, to avoid the gassification of the oil low-
boiling products and the cavitation. The cavitation compromises the burner operation, it causes the pump to break too. The diagram on
Fig. 12 roughly shows the inlet pump pressure according to the oil temperature.
Pump operating maximum pressure (both for the supplying system and burner)
Remember that pumps and all the system components through which the oil circulates, feature an upper limit. Always read the techni-
cal documentation for each component. Schemes on Fig. 13 and Fig. 14 are taken from UNI 9248 "liquid fuel feeding lines from tank to
burner" standard and show how a feeding line should be designed. For other countries, see related laws in force. The pipe dimensio-
ning, the execution and the winding dimensioning and other construcitve details must be provided by the installer.
Adjusting the supplying oil ring
According to the heavy oil viscosity used, in the table below indicative temperature and pressure values to be set are shown.
Note: the temperature and pressure range allowed by the supplying ring components must be checked in the specifications table of the
components themselves.
Tab. 1 - Supply pipeline hydraulic scheme 3ID0024, pump n.4
Burner adjustments
The table below shows indicative values of temperature and pressure to be set on the burner devices, according to the viscosity of the
heavy oil used. The oil temperature should be set on TR resistor thermostat in order to get about 10 - 40 cSt (2 - 5 °E) viscosity at the
nozzle. The oil temperature must no exceed 160°C.
Tab. 2 - Burner - hydraulic scheme 3I2D01, pump n.2
HEAVY OIL VISCOSITY AT 50 °C
PIPELINE
PRESSURE
PIPELINE
TEMPERATURE
cSt (°E) bar °C
< 50 (7) 1- 2 20
> 50 (7) < 110 (15) 1- 2 50
> 110 (15) < 400 (50) 1- 2 65
> 400 (50) < 4000 (530) 1- 2 100
VISCOSITY
AT 50 °C
OIL PRESSURE
AFTER
BURNER PUMP
(N. 2 in 3I2D01)
OIL PRESSURE
AFTER OIL
METERING VALVE
(N. 14 IN 3I2D01)
TEMPERATURE OF
THE PRE-HEATING
RESISTORS
THERMOSTAT TR
TEMPERATURE OF
THE RESISTORS
SAFETY
THERMOSTAT TRS
TEMPERATURE OF
THE PLANT
ENABLING
THERMOSTAT TCI
min max min max min max
°E bar bar °C °C °C
< 50 (7) 5 8 0.5 2 70 95 190 50
> 50 (7) < 110 (15) 5 8 0.5 2 75 105 190 60
> 110 (15) < 400 (50) 5 8 0.5 2 100 140 190 70
> 400 (50) <4000 (530) 5 8 0.5 2 140 160 190 70
ATTENTION: Atomizing air pressure is tipically set at 0.1 ÷ 0.3 bar lower than oil pressure.