JPH11141860A - Dust trap device of combustion device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely trap and remove the dust in the air flow to be introduced into an air volume detection sensor. SOLUTION: A part of the combustion air is introduced from an inlet side 43 to a dust trap passage 37. First U-turn walls 41a and second U-turn walls 41b are provided in an array on one side of a passage side wall of the dust trap passage 37 and on a passage side wall opposite thereto, respectively. The flow of the air passing through the dust trap passage 37 is converted into the U-turn flow in the opposite direction by the first U-turn walls 41a, and again converted into the U-turn flow by the second U-turn walls 41b, and the air flow is thus passed in a meandering manner. When the air flow is U-turned, the dust contained in the air is removed from the route of the air flow by its inertia force, and collided with the first U-turn walls 41a and the second U-turn walls 41b to be trapped and removed. The air free from any dust is introduced to an air volume detection sensor 16 to prevent the dust from being adhered to the air volume sensor 16.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to dust that is provided in a combustion device such as a water heater or a bath kettle, and captures and removes dust (dust) in the air guided to a flow rate detection sensor that detects a flow rate of combustion air. The present invention relates to a trap device.

[0002]

2. Description of the Related Art FIG. 3 shows a system configuration of a water heater under development by the applicant. In FIG.
The apparatus main body 2 is accommodated therein, and a combustion chamber 3 is provided inside the apparatus main body 2, and a burner 4 is installed below the combustion chamber 3. A gas nozzle 7 attached to a nozzle header 6 is opposed to the gas introduction section 5 of the burner 4, and a gas supply passage 8 is connected to the nozzle header 6. The gas supply passage 8 has a nozzle header 6
Valve 10 for supplying and shutting off gas to the burner 4 and proportional valve 11 for controlling the supply amount of gas to the burner 4 by the opening amount
And an original solenoid valve 12 for opening and closing the gas supply passage 8. A combustion fan 13 for supplying and discharging burner combustion is provided below the burner 4, and an air chamber 14 is formed between the combustion fan 13 and the burner 4.

[0003] Between the air chamber 14 and the combustion chamber 3, there is provided an air distribution passage 15 for taking in and flowing a part of the combustion air supplied from the combustion fan 13 to the burner 4. An airflow detection sensor 16 that detects the airflow of the combustion air supplied from the combustion fan 13 to the burner 4 is provided in the branch passage 15. The air volume detection sensor 16 is constituted by an appropriate sensor having a function of directly or indirectly detecting the air volume, such as a hot-wire heater type wind speed sensor or a differential pressure sensor.

[0004] Above the combustion chamber 3 is a hot water supply heat exchanger 1
A water supply passage 18 is connected to the inlet side of the hot water supply heat exchanger 17. The water supply passage 18 has a water amount sensor 20 for detecting a water supply flow rate and a water supply temperature sensor 21 for detecting a water supply temperature. Is provided. A hot water supply passage 22 is connected to the outlet side of the hot water supply heat exchanger 17, and the hot water supply passage 22 is provided with a hot water supply temperature sensor 23 for detecting a hot water supply temperature and a water amount control valve 24 for controlling a hot water supply flow rate.

The operation of the water heater is controlled by a controller 25, to which a remote controller 26 for setting operating conditions such as hot water temperature is connected by signal.

[0006] The control device 25 controls the gas supply amount by the opening amount of the proportional valve 11 so that the hot water supply temperature becomes the hot water supply set temperature set by the remote controller 26, and also controls a predetermined appropriate air-fuel ratio. The rotation of the combustion fan 13 is controlled so as to be as follows. The control of the air volume of the combustion air will be described in more detail. The control device 25 is provided with data on the relationship between the amount of combustion heat and the amount of air supplied (air volume), and the target air volume corresponding to the required combustion heat amount obtained by calculation. And controls the rotation of the combustion fan 13 so that the air volume detected by the air volume detection sensor 16 becomes the target air volume. In FIG. 3, reference numeral 27 denotes a fan rotation detection sensor that detects the rotation of the combustion fan 13 per unit time.

[0007]

As described above, a part of the combustion air supplied from the combustion fan 13 to the burner 4 is diverted through the air distribution passage 15 to detect the fan airflow.
By performing the rotation control of the combustion fan 13 based on the air volume detection information, a suitable air-fuel ratio control in which the amount of combustion heat and the air volume match can be performed. However, combustion fan 1
The air taken in from the outside by 3 contains dust such as dust and trash, and the air volume detection sensor 16 directly contacts the air passing through the air branch passage 15 to detect the air volume. Adheres to the air volume detection section, and as the amount of dust attached increases, the air volume detection performance of the air volume detection sensor 16 deteriorates, and the reliability of long-term air volume detection is impaired. There is a problem that the accuracy of the fuel ratio control is also reduced.

In order to solve such a problem, the applicant has proposed a dust trap device incorporating an air flow detecting sensor 16 as shown in FIG.

In this proposed dust trap device, a trap passage 31 is formed on the front surface side of a body 30 through a partition 30 and a sensor installation space 32 is formed on the back surface side as shown in FIG. . The trap passage 31 has trap walls 33 projecting from right and left side walls of the passage at right angles. And the trap passage 3 on the left and right in the center
1 is provided, and the left and right trap passages 3 are provided.
1 is communicated via the sensor installation space 32.

That is, a communication hole 35a communicating with one end of the sensor installation space 32 is formed in the left trap passage connected to the partition wall 34, and a communication hole 35a is formed in the right trap passage 31 at the other end of the sensor installation space 32. A communication hole 35b for communication is provided, and the flow of wind introduced from the entrance 36 of the trap passage 31 on the left side is guided to the sensor installation space 32 on the back side from the communication hole 35a through the trap passage 31 on the left side. The wind passing through the installation space 32 is guided from the communication hole 35b to the right trap passage 31 formed on the front surface side, and is sent out from the outlet 37 of the trap passage 31 through the right trap passage 31. Has become.

The sensor installation space 32 is a space of a straight path connecting the communication holes 35a, 35b arranged side by side via the partition wall 34 at the shortest distance. A detection sensor 16 is provided. In this dust trap device, the inlet side 36 is set to the air chamber 14 side, and the outlet side 37 is set to the combustion chamber 3 side, and is provided in the air distribution passage 15.

In this dust trap device, the wind of the flowing combustion air is meandered by the trap wall 33 as shown by the arrow in FIG. However, since the dust contained in the air receives the inertial force in the straight traveling direction, it cannot be bent sharply, but hits the trap wall 33 and is prevented from advancing, the dust is captured and removed, and the wind from which the dust is removed is removed. By entering into the sensor installation space 32, dust is prevented from adhering to the air volume detection unit of the air volume detection sensor 16, the air volume detection accuracy of the air volume detection sensor 16 is guaranteed for a long time, and the accuracy and reliability of the air volume detection are improved. It is to try to raise it.

However, since the proposed dust trap device shown in FIG. 4 has a configuration in which the trap wall 33 protrudes substantially perpendicularly from the trap passage 31, the direction of the wind passing through the trap passage 31 is 90 ° at the maximum. In the case of dust having a small mass contained in the air, the inertia force in the straight traveling direction is small, so that the dust flows along the meandering path of the wind without colliding with the trap wall 33. There is a problem that the dust enters the sensor installation space 32, and the dust having a large mass can be trapped and removed in the trap passage 31, but the small dust having a small mass cannot enter the sensor installation space 32 without being completely captured. However, there is a problem that the dust adheres to the air volume detecting portion of the air volume detecting sensor 16, and the performance of capturing and removing dust is not yet sufficient. It was necessary.

The apparatus shown in FIG.
Since the communication holes 35a and 35b are arranged adjacent to each other through the through hole, and the sensor installation space 32 is provided in a form in which the communication holes 35a and 35b are connected at the shortest distance in a straight line,
The wind that enters the sensor installation space 32 from the communication hole 35a side is bent at a right angle, the flow path fluctuates due to the course of the path, and the straight path of the sensor installation space 32 is short, so that the wind is bent at a right angle from the communication hole 35a. Since the entered wind contacts the air flow detection sensor 16 in a state where the flow velocity fluctuation is not eliminated and the air flow is detected, the detected value of the air flow fluctuates due to the flow velocity fluctuation, and there is a problem that an accurate air flow cannot be accurately detected. Occurs.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and a first object of the present invention is to reliably capture and remove dust in air taken into an air distribution passage so as to eliminate dust. A second object of the present invention is to provide a dust trap device capable of introducing natural air into the airflow detection sensor.
Another object of the present invention is to provide a dust trap device capable of guiding a clean air from which dust has been trapped and removed into a rectified state without fluctuation in flow velocity to a flow rate detection sensor in addition to a function of reliably trapping and removing the dust. It is in.

[0016]

The present invention employs the following means to achieve the above object. That is, in the first invention, an air distribution passage is provided for taking in and flowing the combustion air supplied to the combustion section, and an air flow detection sensor is provided in the air distribution passage, and at least the air flow detection sensor is provided. In a dust trap device of a combustion device provided on an upstream air distribution passage side to capture and remove dust in ventilation air guided to the air flow detection sensor, the dust trap device is at least upstream of the air flow detection sensor. The communication passage portion is formed as a dust trap passage, and a plurality of trap walls alternately protruding into the passage from the opposing passage inner wall side of the dust trap passage are arranged in the passage length direction. The trap wall protruding from the side is formed by a folded wall-shaped first U-turn wall protruding in a direction in which the flow of wind is U-turned, and the inner wall of the opposite passage is formed. The trap wall protruding from the side obliquely projects in the forward direction of the flow of the wind, and the second U-turn wall changes the direction of the wind in the forward direction by re-turning the wind generated by the first U-turn wall. The formed configuration is a means for solving the problem.

According to a second aspect of the present invention, in the apparatus having the configuration of the first aspect, the first U-turn wall and the second U-turn wall are overlapped with each other at a protruding tip side through a gap in a passage length direction. The tip of the first U-turn wall and the second U-turn wall of the overlapping portion have an acute angle to allow the wind to flow from the tip of the first U-turn wall to the second.
This is a means for solving the problem with a configuration in which the distance between the first U-turn wall and the second U-turn wall is reduced toward the front end side of the U-turn wall.

Further, the third invention is the first or second embodiment.
A sensor installation passage that is turned 180 degrees from the dust trap passage so as to communicate with the dust trap passage on the exit side of the dust trap passage; A straight-flow rectifying passage section having a narrow passage cross-sectional area is formed in the central region of the passage length of the passage, and the rectifying passage is provided with an airflow detection sensor as a means for solving the problem.

According to a fourth aspect of the present invention, in the apparatus having the configuration of the third aspect of the present invention, a dust trap passage for reverse wind, which is turned 180 ° with respect to the sensor installation passage, is provided on the exit side of the sensor installation passage. A first U-turn wall and a first U-turn wall, which are disposed adjacent to the sensor installation passage and communicate with the dust trap passage for reverse wind and project in a direction opposite to the trap wall of the dust trap passage communicating with the upstream side of the sensor installation passage. 2
It is a means to solve the problem with a configuration in which a U-turn wall is provided.

According to a fifth aspect of the present invention, there is provided the apparatus according to the fifth aspect, wherein the dust trap passage, the sensor installation passage, and the headwind dust trap passage are integrally formed as a unit. Means to do that.

Further, the sixth invention is characterized in that the first to fifth embodiments
Wherein the inlet side of the dust trap passage is on the lower side and the outlet side of the dust trap passage is on the upper side in the air distribution passage in a vertical position. It is a means to solve the problem.

In the present invention, the wind of the combustion air introduced into the air distribution passage enters the dust trap passage of the dust trap device. A trap wall of a first U-turn wall that protrudes a U-turn (U-turn) is protruded from one side wall surface of the dust trap passage, and a flow of the wind U-turned by the first U-turn wall is formed on an opposite passage wall side. A trap wall of the second U-turn wall that protrudes U-turn and leads to a forward flow is protruded, and the first U-turn wall and the second U-turn wall are alternately arranged in a direction in which a plurality of winds flow. The flow of the wind is repeated in the reverse direction and the forward direction to change the direction of the flow in a U-turn shape, and when the flow of the wind makes a U-turn, the direction of the flow of the wind is substantially at a large angle exceeding 90 ° (almost 18
(The angle is close to 0 °), so that not only large-mass dust, but also small-mass dust can be bent by the inertial force without hitting the trap wall and colliding with the trap wall. (The first and second U-turn walls) are trapped and removed, whereby clean air from which dust has been removed is guided to the air volume detection sensor.

Further, by providing a sensor installation passage adjacent to the trap passage so as to communicate with the outlet side of the trap passage, a long rectifying passage section can be formed in the sensor installation passage. By arranging the airflow detection sensor in this rectification passage section, it becomes possible to rectify the wind entering from the dust trap passage and guide the flow of the wind to the airflow detection sensor without turbulence. Therefore, it is possible to accurately detect an accurate air volume without being affected by the flow velocity fluctuation by the air volume detection sensor.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings. The dust trap device of the present embodiment is provided in the air distribution passage 15 of the water heater shown in FIG. 3, and the system configuration of these water heaters is the same as that described in FIG. The same portions are denoted by the same reference numerals, and the description thereof will not be repeated.

The dust trap device of this embodiment has a built-in air volume detection sensor 16, and its configuration is shown in FIG.

In FIG. 1, a main dust trap passage 37, a sensor installation passage 38, and a head wind dust trap passage 40 are arranged and formed side by side in the body main body 28 in order. That is, the entrance side of the sensor installation passage 38 communicates with the exit side of the dust trap passage 37, and the sensor installation passage 38 is connected to the dust trap passage 37.
The dust trap passage 37 is disposed adjacent to the dust trap passage 37 in a state where the direction is changed by 180 °, and the output side of the sensor installation passage 38 communicates with the entrance side of the dust trap passage 40 for backwind. The headwind dust trap passage 40 is disposed adjacent to the sensor installation passage 38 in a state where the direction is changed by 180 ° with respect to the sensor installation passage 38, and the dust trap passage 37, the sensor installation passage 38, and the headwind dust The trap passage 40 is integrally formed in the body 28 and is unitized.

The dust trap passage 37 is formed as a rectilinear straight passage, and the trap walls 1 which alternately protrude into the passage from the opposing inner wall surfaces of the dust trap passage 37 are arranged in the passage length direction. It is provided.

A trap wall projecting from one of the right and left side walls of the dust trap passage 37, that is, the trap wall projecting from the inner wall surface of the right passage in FIG. 41a. Further, the first U-turn wall 41a is formed from the inner wall surface side of the passage opposite to the dust trap passage 37.
The direction of the flow of the wind, which has been changed by approximately 180 ° in the U-turn direction, is again U-turned (approximately 180 °).
A second U-turn wall 41b is formed to change the direction of the flow of the wind to the forward direction (by changing the direction), and the second U-turn wall 41b is formed in the direction of the forward flow of the wind (the straight-line flow of the dust trap passage 37). (Direction).

The first U-turn wall 41a and the second U-turn wall 41b overlap each other at their protruding front ends via a gap 42 in the passage length direction. In FIG. 1, this overlap section is indicated by A.
The first U-turn wall 41a of the overlapping portion
And the second U-turn wall 41b have an acute angle α, and the flow of wind from the entrance side 43 of the dust trap passage 37 to the exit side 44 of the dust trap passage 37 is increased by the front end of the first U-turn wall 41a. The second U-turn wall 4 from the side
1b, the first U-turn wall 41a
The first U-turn wall 41a is formed by narrowing the space 42 between the first U-turn wall 41a and the second U-turn wall 41b.
When the air exits from the outlet throttle opening 45 at the interval 42 of the overlap portion of the second U-turn wall 41b, the flow rate of the air flow is increased and is sent to the next U-turn path.

FIG. 2 shows the action of catching and removing dust 46 contained in the wind passing through the dust trap passage 37 in this embodiment. The wind passing through the dust trap passage 37 follows the route indicated by the arrow and travels meandering in a U-turn shape. That is, the wind traveling in the dust trap passage 37 makes a U-turn in the opposite direction by the first U-turn wall 41a and enters a space surrounded by the second U-turn wall 41b and the left side wall of the passage. And this wind flow is the second
As the U-turn is again performed by the U-turn wall 41b and the direction is changed by approximately 180 °, the direction is meandering while sequentially changing the direction in a U-turn shape.

As described above, since the wind flow largely changes the direction of 180 ° by the U-turn, the dust contained in the wind flow tends to advance in the tangential direction of the wind bending path due to its inertia force. When the wind turns largely in a U-turn, even small dust cannot follow the turn of the large flow, deviates from the path of the wind and collides with the first U-turn wall 41a, and the dust 46 Is captured and removed by the first U-turn wall 41a.

After the U-turn in the opposite direction, the wind that has entered the space surrounded by the second U-turn wall 41b and the left side wall of the passage through the opening 47 on the tip side of the first U-turn wall 41a is again applied by the second U-turn wall 41b. The direction is changed in a U-turn shape by changing the direction by almost 180 ° .During this U-turn in the forward direction, the wind flow changes greatly again. Left side wall and second U-turn wall 4
1b to be captured and removed.

As described above, when the wind flow repeatedly changes in the U-turn shape in the reverse direction and the forward direction, the dust 46 contained in the air flow is efficiently captured and removed.
By repeatedly capturing and removing dust by repeating the U-turn change of the flow, it is possible to obtain clean air in which dust components are completely captured and removed in the final U-turn portion.

In particular, in this embodiment, the overlapping gap 42 between the first U-turn wall 41a and the second U-turn wall 41b increases the flow velocity by reducing the passage area when exiting the outlet throttle opening 45. Since the next U-turn is performed in a state where the flow velocity is increased, the inertia force of the dust 46 is increased by an amount corresponding to the increase in the flow velocity, and the dust 46 deviates from the bending path of the wind flow by the increase in the inertia force. Since the efficiency of trapping and removal is increased, the effect of trapping and removing dust 46 can be further enhanced, and the dust trap passage 37 is shortened to reduce the first U-turn wall 41a.
Even if the number of the second U-turn walls 41b is reduced, dust can be reliably removed, so that the dust trap device can be downsized.

In addition, in this embodiment, even when the flow of the wind moves from the opening 47 on the tip side along the first U-turn wall 41a to the next U-turn operation in the forward direction, the passage is cut off by the opening 47. Because the area is narrowed,
Regardless of whether the operation shifts to the reverse direction or the forward direction of the U-turn, the U-turn operation is performed with the flow velocity accelerated once, and the dust removal effect by the U-turn operation of the wind flow is further enhanced. Becomes

Further, when the wind passes through the outlet-side aperture openings 45 and 47, the cross-sectional area of the wind passage is gradually narrowed, so that the change of the wind is continuously and smoothly performed. The effect that the pressure loss of the wind flow can be reduced as compared with the case where the pressure is rapidly reduced is obtained.

The sensor installation passage 38 has a large passage cross-sectional area at the entrance and the exit side, and the cross-sectional area of the passage is narrowed in a central region (a central region on the passage) of the sensor installation passage 38. A straight flow straightening passage section L is formed. In the present embodiment, the passage section from the entrance of the sensor installation passage 38 to the rectifying passage section serves as a wind introduction portion for continuously and gently narrowing the cross-sectional area of the passage. It is a passage portion in which the passage sectional area is gradually and continuously enlarged. An air flow detection sensor 16 is provided at an intermediate portion of the straightening passage section L.

Since the length of the sensor installation passage 38 is the same as the length of the dust trap passage 37, the rectification passage section L can be formed as a long section. Since the cross-sectional area of the passage on the entry side that enters the air passage is narrowed gently, it is possible to guide the turbulence of the wind coming out of the dust trap passage 37 to the rectifying passage section L while calming the turbulence. Even if the air enters the rectification passage section L, the rectification passage section L is secured in a long section, so that the wind flows through the rectification passage section L so that the flow of the wind is rectified and the flow rate fluctuation is removed in a state where the flow velocity fluctuation is removed. It is possible to guide the air to the sensor 16, whereby the air volume detection sensor 16 accurately detects the air volume of the combustion air supplied from the combustion fan 13 to the burner 4. It is what is possible.

The backwind dust trap passage 40 has a first U-turn wall 41a and a second U-turn wall 41b from both right and left sides of the passage, similarly to the dust trap passage 37.
Are alternately protruded. The difference between the dust trap passage 40 for reverse wind and the dust trap passage 37 is that the first U-turn wall 41a and the second
The projecting direction of the U-turn wall 41b is opposite to that of the dust trap passage 37, and the other configuration is the same as that of the dust trap passage 37. For example, when the water heater is installed outdoors, when the headwind blows on the water heater side when the water heater is installed outdoors, the headwind dust trap passage 40 generates the headwind dust. When the wind enters from the outlet side 48 of the trap passage 40 as headwind, dust contained in the headwind is removed by the same operation as the dust trapping and removing operation of the dust trap passage 37, and the wind in the opposite direction is generated by the headwind dust. When the air flows from the trap passage 40 to the sensor installation passage 38, the dust contained in the headwind is removed so that clean dust-free air comes into contact with the airflow detection sensor 16. This is to prevent the dust component of the headwind from adhering to the head.

In the dust trap device of this embodiment, the inlet side of the dust trap passage 37 is set to the air chamber 14 side, and the outlet side 48 of the dust trap passage 40 for backward wind is set to the combustion chamber 3 side, and the air distribution passage 15 is used. It is interposed (attached).

According to the dust trap device of this embodiment, a part of the supply air of the burner combustion is taken into the air diverting passage 15 and the dust can be surely captured and removed before reaching the air flow detecting sensor 16. In addition, it is possible to completely prevent dust from adhering to the air volume detection sensor 16 by guiding the clean air containing no dust to the air volume detection sensor 16 side.

In particular, as shown in FIG. 1, the dust trap passage 37 is installed in the air distribution passage 15 in a vertical position with the entrance side 43 of the dust trap passage 37 on the lower side and the exit side 48 of the dust trap passage for reverse wind 40 on the upper side. By doing so, the first U-turn wall 41
a and the dust caught and removed by the second U-turn wall 41b fall into the dust receiving portion 50 formed by the base side of the second U-turn wall 41b and the passage side wall due to gravity, and are received. It is possible to more reliably prevent entry into the passage 38 side.

The present invention is not limited to the above-described embodiment, but can adopt various embodiments. For example,
In the above-described embodiment, an example in which the dust trap device is provided in the water heater is shown. However, the combustion equipment equipped with the dust trap device is not limited to the water heater, for example, an air volume detection sensor 16 such as a bath pot or a combined bath / hot water supply machine. Any device may be provided as long as it is provided in the air distribution passage 15, and is applicable to various various combustion devices.

In the above embodiment, one end of the air distribution passage 15 is communicated with the air chamber 14 and the other end is connected to the combustion chamber 3.
However, the configuration of the air distribution passage 15 is not necessarily limited to the configuration shown in FIG. 3, and the air distribution passage 15 can detect the combustion air supplied to the burner 4. It should just be installed in.

Further, in the above embodiment, the first U-turn wall 41a and the second U-turn wall 41b have an acute angle of α, but they may be arranged, for example, in parallel. However, as in the present embodiment, by giving an acute angle of α, the effect of capturing and removing dust can be enhanced by accelerating the wind speed of the wind exiting the outlet throttle opening 45, and the pressure of the air flow can be increased. The effect that the loss can be reduced can be obtained, and it is preferable that an acute angle of α is provided between the first U-turn wall 41a and the second U-turn wall 41b as in the present embodiment.

Further, in the present embodiment, the dust trap passage 37, the sensor installation passage 38, and the head wind dust trap passage 40 are formed integrally with the body 28 to form a unit device. , 38,
The unit 40 may have a separate structure instead of a unit structure. In this case, for example, in FIG. 3, an independent air flow detection sensor 16 is provided in the air flow passage 15, and a dust trap passage 37 is provided in the air flow passage 15 on the upstream side of the air flow detection sensor 16, A dust trap passage 40 for backward wind may be provided in the air distribution passage 15 downstream of the detection sensor 16. However, as in the present embodiment, each passage 3
By making the units 7, 38, and 40 into a unit configuration, the effect of facilitating handling such as attachment and detachment of the dust trap device can be obtained. In this embodiment, a dust trap passage 40 for the reverse wind is provided in the dust trap device.
However, the dust trap passage 40 for backward wind can be omitted.

[0047]

According to the dust trap apparatus of the present invention, a plurality of first U-turn walls and a plurality of second U-turn walls are formed in the dust trap passage through which the wind of the combustion air passes in the length direction of the passage. The flow is U-turned in the reverse direction using the first U-turn wall, and U-turned again in the forward direction using the second U-turn wall.
The wind flow can be made to turn in the reverse direction and the forward direction, respectively, to allow the flow of the wind. Therefore, when the flow of the wind makes a U-turn, the direction of the flow of the wind changes greatly, so that the dust component contained in the wind flow cannot follow the large bending change of the wind due to its inertia force. The first U-turn wall, the second U-turn wall, and the side wall of the passage collide with each other, so that the dust is captured and removed. This dust-removing action is repeatedly performed each time the wind flow changes in a U-turn shape. Therefore, the dust components in the air are completely captured and removed while exiting the dust trap passage, thereby enabling the clean air containing no dust to be guided to the air volume detection sensor, and the dust components are detected by the air volume detection. It is possible to reliably prevent the problem that the air volume detection performance is reduced by adhering to the detection unit of the sensor.

In particular, the protruding distal ends of the first U-turn wall and the second U-turn wall are configured to overlap each other via a gap in the length direction of the passage, and the first portion of the overlapping portion is formed.
By providing a sharp angle between the tip side of the U-turn wall and the second U-turn wall, it is possible to shift to the next U-turn operation in a state where the flow of the wind is gradually reduced and the flow velocity is accelerated, The acceleration of the flow velocity makes it possible to increase the inertial force of the dust contained in the wind. By increasing the inertial force, the dust deviates from the path in the U-turn direction of the wind and the first U-turn wall and the second U-turn wall. Thus, the effect of being trapped and removed by colliding with the trap wall or the like is enhanced, and thereby the dust component can be trapped and removed efficiently. Moreover, since the cross-sectional area of the wind flow is gradually narrowed by the acute angle, the pressure loss of the wind flow can be reduced.

Further, a sensor installation passage is formed adjacent to the dust trap passage so as to communicate with the outlet side of the dust trap passage, and a rectification passage section is formed in a central region of the sensor installation passage, so that rectification is performed. Since the passage section can be formed as a long section, the flow of air entering from the dust trap passage side is preferably rectified, and the rectified air flow without fluctuation in flow velocity is detected in the rectification passage section. Since the airflow can be guided to the sensor, an effect of accurately detecting the air volume without being affected by the fluctuation of the flow velocity can be obtained.

Furthermore, by providing a dust trap passage for headwind on the exit side of the sensor installation passage, for example, when the operation of the combustion equipment is stopped, the headwind blows into the combustion equipment, and the headwind is generated. When passing through the headwind dust trap passage, dust components contained in the headwind can be captured and removed, preventing the dust components contained in the headwind from adhering to the detection unit of the airflow detection sensor. It is possible to do.

Further, since the dust trap passage, the sensor installation passage, and the backwind dust trap passage are integrally formed as a unit, handling such as attaching the dust trap device of the present invention to the air distribution passage is very easy. This has the effect of being easier.

Further, by installing the dust trap device of the present invention in the air distribution passage in a vertical position with the entrance side of the dust trap passage being on the lower side and the exit side of the dust trap passage being on the upper side, The dust in the air captured and removed by the above is received by the dust receiving portion formed by the root side of the trap wall of the first U-turn wall and the passage side wall by the gravitational action of the dust, and the state is stably maintained. it can. This makes it possible to more effectively prevent dust from entering the passage on the airflow detection sensor side from the dust trap passage side,
This makes it possible to further enhance the effect of capturing and removing dust.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a cross section of an embodiment of a dust trap device for a combustion apparatus according to the present invention.

FIG. 2 is an explanatory diagram of an action of trapping and removing dust in air in the embodiment.

FIG. 3 is a system configuration diagram of a water heater representing a combustion device.

FIG. 4 is an explanatory diagram of a configuration of a dust trap device previously proposed by the applicant.

FIG. 5 is a cross-sectional configuration diagram of an installation portion of an air volume detection sensor 16 of the device shown in FIG.

[Explanation of symbols]

 15 Air distribution passage 37 Dust trap passage 38 Sensor installation passage 40 Backwind dust trap passage 41 Trap wall 41a First U-turn wall 41b Second U-turn wall

Claims (6)

[Claims] An air distribution passage for taking in and flowing combustion air supplied to a combustion section is provided, and an air flow detection sensor is disposed in the air distribution passage, and at least an upstream air flow detection sensor is provided on the upstream side of the air flow detection sensor. In a dust trap device of a combustion device provided on an air distribution passage side for capturing and removing dust in ventilation air guided to the air flow detection sensor, the dust trap device is a communication passage portion at least upstream of the air flow detection sensor. A plurality of trap walls alternately protruding into the passage from the opposing passage inner wall side of the dust trap passage are provided in the passage length direction, and project from the one passage inner wall surface side. Trap wall is formed by a first U-turn wall having a folded wall shape protruding in a direction in which the flow of wind is U-turn, and protruding from the inner wall surface side of the opposite passage. The trap wall is formed by a second U-turn wall which obliquely projects in the forward direction of the wind flow, re-turns the wind generated by the first U-turn wall and turns the wind into the forward flow direction. There is a dust trap device for combustion equipment. 2. The first U-turn wall and the second U-turn wall are overlapped at their protruding front ends via a gap in the length direction of the passage, and the front end side of the first U-turn wall and the second U-turn wall of the overlapping portion. 2. The device according to claim 1, wherein the distance between the first U-turn wall and the second U-turn wall decreases as the wind moves from the front end side of the first U-turn wall to the front end side of the second U-turn wall with an acute angle.
A dust trap device for the combustion equipment according to the above. 3. A sensor installation passage which is turned 180 ° with respect to the dust trap passage is provided adjacent to the dust trap passage on the outlet side of the dust trap passage.
2. A straight-flow rectification passage section having a narrow passage cross-sectional area is formed in a central region of a passage length of the sensor installation passage, and an airflow detection sensor is disposed in the rectification passage. Item 3. A dust trap device for a combustion device according to Item 2. 4. A dust trap passage for reverse wind, which is turned 180 ° with respect to the sensor install passage, is provided adjacent to the sensor install passage on the exit side of the sensor install passage, and the reverse wind dust trap passage is provided. 4. A dust trap according to claim 3, wherein a first U-turn wall and a second U-turn wall protrude in opposite directions to a trap wall of a dust trap passage communicating with an upstream side of the sensor installation passage. apparatus. 5. The dust trap device for a combustion apparatus according to claim 4, wherein the dust trap passage, the sensor installation passage, and the headwind dust trap passage are integrally formed as a unit. 6. An air distribution passage having a vertical position with an inlet side of a dust trap passage on a lower side and an outlet side of the dust trap passage on an upper side.
A dust trap device for a combustion apparatus according to claim 1.