Bell mouth, air supply assembly including the bell mouth, and air supply control system using the bell mouth

An air supply control system of a water-heating device, comprising:

• a blower configured to forcibly feed air into a burner of the water-heating device;
• a bell mouth configured to deliver, to the blower, the air introduced from outside the water-heating device;
• a differential-pressure acquisition device connected to the bell mouth to obtain a differential pressure of the air passing through the bell mouth;
• and
• a processor configured to receive the obtained differential pressure and control the blower, based on the obtained differential pressure,
• wherein the bell mouth includes:
• an upstream-side opening formed to allow the introduced air to pass through and defined by a upstream body;
• a differential-pressure generation part located downstream of the upstream-side opening with respect to a flow direction of the air, the differential-pressure generation part having a structure configured to reduce pressure of the air passing through the differential-pressure generation part;
• and
• a downstream-side opening formed to allow the air passing through the differential-pressure generation part to pass through and defined by a downstream body,
• wherein the differential pressure obtained by the differential-pressure acquisition device corresponds to a difference between pressure in the upstream-side opening and pressure in the downstream-side opening,
• wherein the upstream body includes an upstream ring portion having an inner circumferential surface configured to define the upstream-side opening and an upstream surrounding portion protruding from a periphery of the upstream ring portion along the flow direction to form, together with the upstream ring portion, an insertion space into which the downstream body is inserted,
• wherein the downstream body includes a downstream measurement portion connected with the differential-pressure acquisition device, and
• wherein the upstream surrounding portion is open in the radial direction such that a measurement portion insertion hole through which the downstream measurement portion passes is formed.

An air supply assembly comprising:

• an air supply duct including a duct body configured to guide introduced air downward, a redirection portion configured to guide the air from the duct body in one direction parallel to a horizontal direction, and a stabilizing portion extending from the redirection portion along a flow direction of the air changed in the redirection portion;
• a guide part disposed in the redirection portion and forming a slope slighter than a slope of a lower end of an inner surface of the redirection portion relative to a vertical direction;
• and
• a bell mouth including a differential-pressure generation part and a measurement portion, the differential-pressure generation part being formed to allow the air delivered from the stabilizing portion to pass through and having a structure configured to reduce pressure of the air passing through the differential-pressure generation part, and the measurement portion being connected to a differential-pressure acquisition device configured to obtain a difference between pressure upstream of the differential-pressure generation part and pressure downstream of the differential-pressure generation part with respect to the flow direction of the air,
• wherein the stabilizing portion is longer than the redirection portion with respect to the flow direction.