JP2011214728A - Hood device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hood device capable of reducing the number of particles flowing into a silencer.SOLUTION: This hood device 40 covers an exhaust gas mixing device and mounted on an intake 32 of the silencer 30 provided with the intake 32. The hood device 40 includes a net member 42 which is mounted on a front face of the intake 32 and to which voltage can be applied, hood sections 47, 48 covering a front face of the intake 32 and having an opening section 49 opened downward, and a charging device 60 for charging dust 80 floating in its internal space.

Description

  The present invention relates to a hood device mounted on a housing such as a silencer of a high voltage electric motor.

  In a thermal power plant, various high-voltage electric motors such as an exhaust gas mixing fan (Gas Mixing Fan: GMF) are operating (for example, see Patent Document 1). When a problem occurs in these electric motors, it takes time for recovery, and stable power supply becomes difficult. For this reason, it is important to prevent failure of these electric motors.

  In addition, high voltage electric motors in thermal power plants often have a large amount of gas flow, such as the exhaust gas mixing fan, and noise is a problem. For this reason, a silencer is attached to the electric motor to reduce noise. On the other hand, high voltage motors tend to be hot because they use high voltages. For this reason, an intake port is provided in the side wall portion of the silencer, and cooling air is taken in from the outside.

Japanese Patent Laid-Open No. 7-133796

  However, the dust floating in the air also flows into the silencer together with the cooling air flowing in from the air inlet. When dust reaches the electric motor inside the silencer, it may adhere to the stator of the electric motor and cause a short circuit. In particular, since the environment around the installation location of the exhaust gas mixing fan and the silencer surrounding it in a thermal power plant is an environment with a lot of floating dust, it is particularly important to take measures against dust.

  An object of the present invention is to provide a hood device capable of reducing the number of particles (dust) flowing into a housing such as a silencer.

(1) The hood device of the present invention is a hood device attached to the intake port in a housing that covers the electric motor and is provided with the intake port, and is attached to the front surface of the intake port and can apply a voltage. A mesh member, a hood portion extending from the outer peripheral side of the mesh member so as to cover the front surface of the intake port, and an opening portion opening in a direction non-parallel to the intake port, and an inner surface of the hood portion And a charging device that charges particles floating in the internal space of the hood portion.

  According to the hood device, the opening of the hood portion is provided in a direction non-parallel to the intake port. For this reason, the airflow from the opening flows from the opening that opens in a direction non-parallel to the intake port, changes direction, and flows into the intake port. That is, air does not flow linearly, and among the dust that has entered the hood device while riding in the airflow, dust having a large mass is displaced from the airflow by the inertial force and moves toward the wall surface of the hood device. It becomes difficult to reach the mouth. Therefore, particles that enter the inside of the electric motor from the intake port are reduced.

  The hood device includes a charging device, and a mesh member capable of applying a voltage is disposed at the intake port. Therefore, when particles that enter the inside of the hood device by riding in an air current from the outside are charged negatively by the charging device, for example, and a positive voltage is applied to the net member, the negatively charged particles are applied to the net member by electrostatic force. It is attracted and adheres to the net member. Therefore, the particles are less likely to flow into the housing that covers the electric motor. Thereby, the number of particles reaching the electric motor inside the housing is reduced, and adverse effects of dust generated in the electric motor, such as a short circuit, can be prevented.

(2) The hood device may be detachable from the housing. By making the hood device detachable, the hood device can be removed, inspected, repaired, etc., when the hood device fails. Therefore, maintenance becomes easy. Also, even if it cannot be repaired, it is sufficient to replace only the hood device, which is less expensive than the case where the entire housing including the housing is replaced. Furthermore, when the hood device breaks down, it is possible to operate only the electric motor with the hood device removed, and there is no need to stop the operation of the electric motor.

(3) In the hood device, the polarity of the particles charged by the charging device is different from the polarity of the voltage applied to the mesh member. For example, when the particles are negatively charged and the net member is positively charged, the particles floating in the air are displaced from the air current by electrostatic force and adhere to the net member. Therefore, particles suspended in the air do not reach the intake port, and particles that enter the interior of the electric motor from the intake port are reduced.

(4) In the hood apparatus, a protective cover that prevents an object having a predetermined size or more from entering the hood portion may be attached to the opening portion. By attaching the protective cover in this way, an operator does not accidentally enter a finger or hand into the hood device, and safety is improved.

(5) The casing to which the hood device is attached may be a silencer that reduces transmission of sound generated by the electric motor to the outside, and the electric motor surrounded by the casing is installed in a thermal power plant. It may be a gas mixing device arranged.
Gas mixing devices in thermal power plants are large and expensive. Therefore, when the particles enter and adhere to the stator or the like, the gas mixing device breaks down and needs to be replaced, the cost becomes high. Moreover, when repairing a gas mixing apparatus, a thermal power plant will be stopped, an electric power supply will be stopped, and damage will become large. However, according to the present invention, the hood device reduces the entry of particles into the gas mixing device, and the failure of the gas mixing device is reduced.

  According to the present invention, it is possible to provide a hood device capable of reducing the number of particles flowing into the interior.

It is a block diagram of the combustion facility of the thermal power plant in which the gas mixing device to which the silencer equipped with the hood device of the present embodiment is attached is installed. It is a perspective view which shows the outline of a silencer and a hood apparatus. It is sectional drawing which shows the concept of a hood apparatus.

  Hereinafter, the hood device 40 according to an embodiment of the present invention and the silencer 30 to which the hood device 40 is attached will be described. FIG. 1 is a schematic configuration diagram of a combustion facility 1 of a thermal power plant in which an exhaust gas mixing device 10 to which a hood device 40 and a silencer 30 are attached is installed. The combustion facility 1 includes a bunker 11 that stores coal transported from a silo (not shown), a pulverized coal device 12 (mill) that converts the coal stored in the bunker 11 into combustible pulverized coal, And a furnace 13 for burning coal pulverized into charcoal.

  The combustion facility 1 further includes an exhaust gas mixing device 10 and an air supply device 14. The air supply device 14 is a device that blows combustion air used for combustion of pulverized coal in the furnace 13 to the exhaust gas mixing device 10. As will be described later, the exhaust gas mixing device 10 includes a fan that mixes combustion air blown from the air supply device 14 and part of the exhaust gas generated from the furnace 13.

  Moreover, the combustion facility 1 removes nitrogen oxides in the exhaust gas discharged from the furnace 13, a denitration device 15 that collects dust in the exhaust gas, and a sulfur oxide in the exhaust gas. The desulfurization apparatus 17 and the chimney 18 which discharges | emits the waste gas processed with this desulfurization apparatus 17 to air | atmosphere are provided. Furthermore, the combustion facility 1 includes a turbine 19 that converts thermal energy generated by combustion in the furnace 13 into mechanical energy, and a power generation device 20 that converts mechanical energy into electrical energy.

  In the combustion facility 1 configured as described above, the coal sent from the bunker 11 is pulverized by the pulverized coal device 12 and sent to the furnace 13. The combustion air and exhaust gas sent from the air supply device 14 are mixed by the exhaust gas mixing device 10 and sent to the furnace 13 as a mixed gas. The pulverized coal is ignited together with fuel (for example, crude oil) (not shown) and burned in a mixed gas atmosphere. The thermal energy generated by the combustion is converted into mechanical energy by the turbine 19, and the mechanical energy is converted into electric energy by the power generation device 20. On the other hand, the exhaust gas generated in the furnace 13 is removed from the chimney 18 after nitrogen oxides are removed by the denitration device 15, soot is removed by the dust collector 16, sulfur oxides are removed by the desulfurizer 17.

  The exhaust gas mixing device 10 includes a gas mixing fan (GMF: gas mixing fan, not shown) for mixing gas and a drive motor (not shown) for driving the gas mixing fan, It is a device that mixes two gases and sends them to the furnace 13. Since a large amount of air flows and is mixed inside the exhaust gas mixing device 10, noise is generated. For this reason, the exhaust gas mixing device 10 is covered with the silencer 30. FIG. 2 is a perspective view schematically showing the silencer 30 and the hood device 40, and FIG. 3 is a cross-sectional view showing the concept of the hood device 40. The silencer 30 is a housing that surrounds the exhaust gas mixing device 10 (not shown in FIGS. 2 and 3). The silencer 30 is manufactured, for example, with a sound-reducing member attached to the inner surface, or the housing itself having a sound-reducing effect.

  A high voltage is supplied to the drive motor of the gas mixing fan disposed inside the silencer 30. The temperature rises when the voltage is continuously supplied for a long time. Therefore, the side wall 31 of the silencer 30 is provided with an intake port 32 for intake of cooling air (see FIG. 3). As a means for sucking air into the silencer 30 from the air inlet 32 of the silencer 30, an air intake fan may be provided, or air may flow into the silencer 30 due to negative pressure generated by the gas mixing fan. In the present embodiment, the air inlet 32 is provided in the side wall 31 along the vertical direction.

  A hood device 40 is attached to the intake port 32. The hood device 40 includes a dust collecting portion 41 that covers the front surface of the air inlet 32. The dust collection portion 41 includes a net member 42 made of a conductive member and an insulating frame portion 43 that covers the outer periphery of the net member 42.

  The net member 42 has a shape similar to that of the air inlet 32 and is smaller than the air inlet 32, and is disposed so as not to contact the side wall portion 31 of the silencer 30. The insulating frame 43 is a frame having a predetermined width that covers the outer periphery of the net member 42. The outer shape of the insulating frame 43 is similar to the intake port 32 and larger than the intake port 32. Holes 44 are provided at four corners of the insulating frame portion 43. On the other hand, screw holes 45 are provided at four corners of the air inlet 32 in the side wall 31 of the silencer 30 at positions corresponding to the holes of the insulating frame 43.

  The hood device 40 further includes a front hood 47 having a curved rectangular plate material extending downward from the upper portion of the insulating frame portion 43 and two sheets extending forward in parallel from both sides of the insulating frame portion 43. And a fan-shaped side hood 48. An opening 49 is formed by the lower side of the front hood 47, the lower side of the side hood 48, and the lower part of the insulating frame 43. The opening 49 is inclined by about 90 degrees (vertically downward) with respect to the direction (lateral direction) in which the dust collection portion 41 (net member 42) is disposed. A net-like or fence-like cover 50 is attached to the opening 49 so that an operator cannot accidentally put a hand or finger into the hood.

  The hood device 40 includes a charging device 60 fixed to the inner surface of the front hood 47. The charging device 60 is, for example, a corona discharge device, and includes a plurality of electrodes 61 arranged in a line with each other. The hood device 40 further includes a power supply unit 70 that applies a voltage to the electrodes 61 and the mesh member 42 outside the side hood 48. The power supply unit 70 can apply a positive or negative voltage to the electrode 61 and the net member 42.

  The hood device 40 is configured such that the hole 44 and the screw hole 45 are aligned with the hole 44 provided in the insulating frame 43 and the screw hole 45 provided in the side wall 31 of the intake port 32 of the silencer 30. Is fixed to the side wall 31 of the silencer 30 by screwing the screw 46. With this screw 46, the hood device 40 can be attached to and detached from the silencer 30.

  With the hood device 40 attached to the silencer 30, air flows into the silencer 30 from the intake port 32. At this time, for example, a positive voltage is applied to the mesh member 42. Then, a negative corona discharge is generated from the charging device 60.

  Then, as shown in FIG. 3, the dust 80 a that enters the hood device 40 by riding in the airflow from the outside is negatively charged by the corona discharge of the charging device 60. The negatively charged dust 80b rides on the air current and travels toward the net member 42. At this time, since the mesh member 42 is applied positively, the dust 80b is attracted by the electrostatic force and adheres to the mesh member 42 (dust 80c). Accordingly, the dust 80 hardly flows into the silencer 30 and only cooling air flows. Thereby, the dust 80 does not easily reach the exhaust gas mixing device arranged inside the silencer 30, and it is possible to suppress the adverse effect of the dust conventionally generated in the exhaust gas mixing device, such as a short circuit.

  As described above, according to the hood device 40 of the present embodiment, the opening 49 of the hood portion (front hood 47, side hood 48) is provided in a horizontal direction that is not parallel to the intake port 32 provided vertically. For this reason, the airflow flowing in from the opening 49 changes direction linearly to the flow chart and flows into the intake port 32. At this time, of the dust 80 that has entered the hood device 40 by riding in the air current, the path of the dust 80 having a large mass is displaced from the air current by the inertial force, moves toward the inner surface of the front hood 47, and reaches the intake port 32. It becomes difficult to do. Accordingly, the dust 80 entering the exhaust gas mixing device 10 from the intake port 32 is reduced.

  Further, the hood device 40 includes a charging device 60, and a mesh member 42 to which a voltage can be applied is disposed at the intake port 32. Accordingly, when the dust 80a entering the hood device 40 by riding in the airflow from the outside is charged negatively by the charging device 60 and a positive voltage is applied to the net member 42, the negatively charged dust 80b is As a result, it is attracted to the net member 42 and adheres to the net member 42. Therefore, the dust 80 is less likely to flow into the silencer 30 that covers the exhaust gas mixing device 10. Thereby, the number of the dust 80 which reaches | attains the exhaust gas mixing apparatus 10 inside the silencer 30 reduces, and the bad influence of the dust 80 which generate | occur | produces in the exhaust gas mixing apparatus 10, for example, a short circuit etc., can be prevented.

  The hood device 40 can be attached to and detached from the silencer 30. By making the hood device 40 detachable in this way, when the hood device 40 breaks down, the hood device 40 can be removed for inspection, repair, and the like. Therefore, maintenance becomes easy. In addition, even if the repair is not possible, it is sufficient to replace only the hood device 40, which is less expensive than the case where the entire silencer 30 is replaced. Further, when the hood device 40 breaks down, it is possible to operate only the exhaust gas mixing device 10 with the hood device 40 removed, and it is not necessary to stop the operation of the exhaust gas mixing device 10, that is, the thermal power plant as a whole.

  In the hood device 40, by attaching a cover 40 that prevents an object having a predetermined size or more to enter the hood portions 47 and 48 in the opening portion 49, a finger or a hand is mistakenly placed in the hood device 40. It is no longer allowed to enter and safety is increased.

  The gas mixing device 10 in a thermal power plant is large in size and expensive. Therefore, when the dust 80 enters and adheres to the stator or the like, the gas mixing device 10 breaks down and is replaced, the cost becomes high. Also, when repairing, the entire thermal power plant is stopped, power supply is stopped, and damage is increased. However, according to the present invention, the number of dust entering the gas mixing device 10 by the hood device 40 is reduced, and the failure of the gas mixing device 10 is reduced.

  As described above, various modifications and changes are possible without being limited to the embodiments described above, and these are also within the scope of the present invention. For example, the charging device 60 is not limited to the corona discharge device, and may be another charging device. Moreover, the opening part 49 of the hood apparatus 40 is not restricted to the thing opened to the perpendicular | vertical downward direction, but should just be non-parallel to the inlet port 32. FIG.

  1: Combustion facility, 2: Exhaust gas mixing device, 30: Silencer, 32: Intake port, 40: Hood device, 47: Front hood, 48: Side hood, 49: Opening, 50 cover, 60: Charging device

Claims (6)

A hood device attached to the intake port in a housing that covers the electric motor and is provided with an intake port,
A net member attached to the front surface of the intake port and capable of applying a voltage;
A hood portion that extends from the outer peripheral side of the mesh member so as to cover the front surface of the intake port, and is provided with an opening that opens in a direction non-parallel to the intake port;
A charging device that is attached to the inner surface of the hood portion and charges particles floating in the internal space of the hood portion;
A hood device comprising: Being detachable from the housing;
The hood apparatus according to claim 1. The polarity of the particles charged by the charging device;
The polarity of the voltage applied to the mesh member is different,
The hood apparatus of Claim 1 or 2 characterized by these. A protective cover for preventing the entry of an object having a predetermined size or more into the hood is attached to the opening.
The hood apparatus of any one of Claim 1 to 3 characterized by these.   The hood device according to any one of claims 1 to 4, wherein the casing is a silencer that reduces transmission of sound generated by the electric motor to the outside.   The hood device according to any one of claims 1 to 5, wherein the electric motor is a gas mixing device arranged in a thermal power plant.

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