When lighting the furnace, a slight positive pressure is required. How can one determine whether there is a slight positive pressure?
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When lighting the furnace, a slight positive pressure is required. How can one determine whether there is a slight positive pressure?
What kind of heating furnace is the device the poster is talking about? ? ?
There are two ways: the first is to have the operator monitor the furnace pressure to ensure it remains slightly positive； Secondly, paper or similar materials can be used to test the draft in the furnace through the fire viewing window; if there is no significant draft, it indicates a slight positive pressure.
It can be determined using the DCS control system by placing a hand at the viewing windows, at the secondary air dampers, and at the natural ventilation openings; if wind is felt flowing inward, it indicates a slight positive pressure. Of course, paper can also be placed at those dampers to see if air is drawn upward. During testing, the flue dampers can be adjusted simultaneously to determine the level of negative pressure and to check whether the system functions properly
It is displayed on the negative pressure gauge of the furnace on the DCS. If making judgments on-site, be sure to stay away from the fire viewing ports or windows to prevent hot air from causing injury when the furnace is under positive pressure.
With an auxiliary combustion chamber, it’s not possible to create a negative pressure. Personally, I think it’s better to have negative pressure when lighting a furnace at atmospheric pressure.
Negative pressure, is there such a thing as a burner with slight positive pressure?
The ignition of the heating furnace should be carried out under negative pressure, with the value of this negative pressure determined based on the size of the furnace. If a positive-pressure flame easily sprays out of the furnace, it can be dangerous.
You can feel it by using your hand or placing a piece of paper over the fire viewing hole. Generally, tubular heating furnaces can be started without a slight positive pressure; it seems that CO and waste heat boilers require a slight positive pressure.
I think micro-positive pressure refers to the pressure beneath the flue dampers, while the pressure in the furnace must be negative; otherwise, backflow wouldn’t occur； The testing method is the same as before. When a normal furnace operates with a slight positive pressure at the top and negative pressure at the bottom, isn’t its efficiency also the highest?
DCS can see it! And also, it’s about testing your feel!
1) Turn to the side to look at the fire viewing window; feel the direction of air flow at that area with your hand to determine it； 2) There should be a diaphragm gauge for negative pressure at the site, which can be used to make judgments based on it ； 3) There is a pressure display on the DCS; contact the operator on site for confirmation ； It is recommended to use the latter two methods; feeling it with your hands is the approach used by experienced craftsmen.
When the furnace is ignited, it is necessary to maintain a slight negative pressure in the furnace chamber to prevent the flame from being extinguished