JPS5838292Y2 - Fin clogging detection device - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a fin clogging detection device for gas water heaters and the like.

When the fins of a heat exchanger in a gas water heater or the like become clogged with soot, etc., the combustibility of the main burner deteriorates, and combustion often continues while generating a large amount of carbon monoxide, which is extremely dangerous.

This invention aims to improve safety by immediately detecting when a fin becomes clogged and, for example, closing a well-known magnetic safety valve to prevent the generation of carbon monoxide.

This will be explained below with reference to the drawings.

Fig. 1 shows an embodiment of the fin clogging detection device according to this invention, in which 1 is an inner shell provided at the lower part of the heat exchanger A;
Reference numeral 2 denotes a pilot combustion chamber which is partitioned and provided on the inner side of the inner shell 1 along its wall surface to guide exhaust gas from a pilot burner 5 (described later). The upper end is opened at a position slightly above the vertically intermediate position within the inner shell 1 to serve as a discharge port 3, and the lower end is opened at a position slightly above the lower end within the inner shell 1 to serve as an air supply port 4.

Reference numeral 5 designates a pilot burner having a flame opening 6 at the upper end and a primary air hole 7 near the lower end. It is positioned so as to protrude from the lower end opening position of the inner shell 1.

Reference numeral e indicates a pilot flame formed at the flame port 6 of the pilot burner 5, and 8 indicates a main burner.

In FIG. 2, a bulge protruding to the outside is formed and the bulge is partitioned into one side of the inner shell 1 to form a combustion chamber 2, and the exhaust port 3 is located approximately in the vertical direction of the inner shell 1. It is located at an intermediate position, and its air supply port 4 is located at almost the same position as the lower end opening position of the inner shell 1.

In the above configuration, when the fins of the heat exchanger A are normal and not clogged, the draft force of the pilot flame e acts, and air is taken in from the air supply port 4 of the combustion chamber 2, and the pilot flame is discharged from the exhaust port 3 of the combustion chamber 2. The exhaust gas e is released and the pilot flame e continues normal combustion.

The fins may become clogged, and the internal pressure in the inner shell 1 (inner shell pressure generated by burning the main burner 8) rises, causing the discharge port 3 to become clogged.
The pressure in the vicinity increases and the exhaust gas from the pilot flame e flows to the exhaust port 3.
The exhaust gas of the pilot flame e formed in the combustion chamber 2 is not discharged and remains in the combustion chamber 2, and the vicinity of the pilot flame e becomes oxygen-deficient, and the pilot flame e becomes unclear. temperature decreases.

If the fins become clogged further, the exhaust gas of the pilot flame e will flow backwards from the exhaust port 3 and overflow from the air supply port 4, and the pilot flame e will no longer be able to maintain its normal shape along this flow.

That is, the pilot flame e is crushed by the pressure (see FIG. 3).

However, if a thermocouple is inserted into this pilot flame e, the thermocouple will be separated from the pilot flame e, so it will sense this and the generated electromotive force will be greatly reduced, allowing fin clogging to be accurately detected and safety to be ensured. It is to maintain it.

For example, when the pilot burner 5 and the main burner 8 are both burning when the fin blockage rate is 0%, the thermocouple inserted during the pilot flame has a generated electromotive force of 19 mV, but the blockage rate is 40%. As a result of experiments, it was found that the voltage decreases to 4 mV when the voltage is 50%.

As is clear from the above, in this invention, the exhaust port 3 of the combustion chamber 2 should be opened at an appropriate position inside the inner shell 1, and the air supply port 4 should be made to protrude outside the inner shell 1. It may be arranged.

Further, the vertical positional changes of the inner shell of the air supply port 4 and the discharge port 3 can be tolerated within a considerable range.

As explained above, this idea is based on the fact that when the fins become clogged, the pilot flame becomes unclear and is further crushed by the backflow of the exhaust gas, so the thermocouple can be separated from the pilot flame and a magnetic safety valve etc. can be activated immediately. This has the effect of preventing poor combustion in the main burner due to fin clogging.

[Brief explanation of the drawing]

1 and 2 are longitudinal sectional front views showing an embodiment of this invention, and FIG. 3 is a partially enlarged sectional view of the main parts thereof. 1... Inner shell, 2... Pilot combustion chamber, 3... Its exhaust port, 4... Its air supply port, 5......・Pilot burner, 6...
The flame hole, e...Pilot flame, A...
·Heat exchanger.

Claims (1)

[Scope of utility model registration request] Pilot combustion chambers 2 are divided and arranged in parallel along the inner shell 1,
The exhaust port 3 of the pilot combustion chamber is opened at an appropriate position within the inner shell 1, and the flame hole 6 of the pilot burner 5 faces the vicinity of the air supply port 4 of the pilot combustion chamber 2. Features a fin clogging detection device.