Regarding pump preheating
Thread Content
Let’s discuss everyone’s methods for preheating pumps
1. Slightly open the hot oil preheating valve to fill the oil pump, then partially open the pump’s outlet vent valve to remove air from the pump; once the air has been removed, close the vent valve. At this point, the gate valve on the outlet pipeline should also be closed； 2. Gradually open the pump inlet valve to preheat the pump, with a preheating rate of no more than 50°C per hour ； The opening degree of the preheating valve should not be too large to prevent the pump from reversing ； 3. Preheating standard: The temperature of the hot oil pump casing must be at least 50 degrees higher than the inlet oil temperature℃ ；
The hot oil pump must be in hot standby to be able to start at any time. Let the pump of the preheating valve be used, with the preheating valve open. For pumps without a preheating valve, slightly open the pump outlet valve. Attention should be paid to both situations: the preheating rate must not be too fast, 50 degrees per hour ； The valve opening should not be too large to prevent the pump from reversing.
Reply to 3# lcwt: Could you explain in detail how you handle exhaust ventilation?
1. The pump should be filled first, by opening the inlet valve to fill it； 2. Then slightly open the drain valve to release air; an excessive opening of the drain valve is sufficient ； 3. Finally, the heat pump is activated; the line connected to the heat pump leads from the pump’s outlet. The valve on this line should be opened slowly, and the rate of temperature increase should be controlled so that it does not exceed 50 degrees per hour. Preheating is complete when the temperature difference between the pump casing and the medium is less than 40 degrees.
So, in the event that hot oil at such high temperatures leaks out through the air release valve, will it not catch fire when exposed to air?
The oil slurry has a low auto-ignition point, so venting it can result in smoking and spontaneous ignition; using water or steam for protection during venting is sufficient, especially since there are people present on site. Re-refined oil, intermediate oil, and residue generally pose no issues; diesel usually causes smoking, while it’s less clear regarding other types of oil