JP2017150741A - VAV or CAV device for kitchen exhaust - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device capable of keeping stable control while considering workability in periodic inspections of a damper portion, an actuator portion, a differential pressure sensor portion and a controller portion in a VAV or CAV device for kitchen exhaust.SOLUTION: A VAV or CAV device for kitchen exhaust is composed of a frame body 2 including connection frames 21, 22 with an exhaust duct and a duct for kitchen apparatus, a damper portion 3 composed of a damper blade for adjusting a wind volume, rotatably journaled on the frame body, an actuator portion 4 for opening and closing the damper blade of the damper portion 3, a differential pressure sensor portion 5 for measuring a wind speed of the frame body 2, a pitot tube 6 for inputting a differential pressure signal obtained by measurement of multipoint wind speed in the frame body 2, to the differential pressure sensor portion 5, and a controller portion 7 for controlling the wind volume in the frame body 2 to a prescribed wind volume while controlling the opening/closing of the damper blade through the actuator portion 4.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a VAV (variable air flow) or CAV (constant air flow) device for kitchen exhaust, and in particular, considering the workability of periodic inspection of the damper portion, actuator portion, differential pressure sensor portion and controller portion in the device, It is an object of the present invention to provide an apparatus capable of maintaining the above control.

As a conventional kitchen exhaust system, a kitchen exhaust system in which an outside air introduction duct is connected in the middle of an exhaust duct to diffuse and dilute odors by the atmosphere is proposed by the invention described in Japanese Patent Laid-Open No. 11-83106 (Patent Document 1). In addition, in the invention described in Japanese Patent Application Laid-Open No. 2002-195618 (Patent Document 2), a kitchen exhaust device that improves the collection performance of mist covered with a nonflammable filter has been proposed.
As for the above-mentioned Patent Document 2, there is proposed a method for efficiently removing oil mist contained in the kitchen exhaust in the kitchen exhaust device disclosed in Japanese Patent Laid-Open No. 2009-45594 (Patent Document 3).
Further, a kitchen exhaust purification cleaning duct and a kitchen exhaust purification device that have an odor removal function in addition to an oil mist removal function and do not require cleaning of the kitchen exhaust duct are described in JP-A-2005-205311 (Patent Document 4). And a kitchen exhaust system that separates the dust from the exhaust gas and exhausts the exhaust gas without using a ventilating fan or a concentrated duct, is proposed by the invention described in Japanese Patent Laid-Open No. 2012-42062 (Patent Document 5). Yes.

  Furthermore, in the invention described in Japanese Patent Application Laid-Open No. 2014-20690 (Patent Document 6), exhaust gas and the like are collected more efficiently than in the conventional exhaust system, reducing power consumption and reducing the installation cost of the exhaust hood. A kitchen exhaust system that can provide an excellent kitchen exhaust system is proposed, and in the invention described in Japanese Patent Application Laid-Open No. 2014-44010 (Patent Document 7), a kitchen exhaust device that improves the exhaust efficiency of exhaust gas is proposed. Has been.

Japanese Patent Laid-Open No. 11-83106 JP 2002-195618 A JP 2009-45594 A JP 2005-205311 A JP 2012-42062 A JP 2014-20690 A JP 2014-44010 A

  In the conventional Patent Documents 1 to 7 described above, although consideration is given to exhaust of exhaust gas to the outside air in the kitchen exhaust device, the exhaust VAV (variable air flow) or CAV (constant air flow) in the kitchen exhaust device is considered. The device is not considered at all.

  Therefore, the present invention is a device in which the damper unit, the actuator unit, the differential pressure sensor unit, and the controller unit required for the configuration of the kitchen exhaust VAV or CAV device are unitized and maintains stable control in the device. It is an object of the present invention to provide a kitchen exhaust VAV or CAV device that can easily and quickly perform periodic inspection work.

  According to a first aspect of the present invention, there is provided a frame having a connection frame for connecting an exhaust duct and a duct for kitchen equipment, a damper part comprising a damper blade for adjusting the air volume that is rotatably supported in the frame, An actuator for opening and closing the damper blade, a differential pressure sensor for measuring the wind speed in the frame, a pitot tube for inputting a differential pressure signal by multipoint wind speed measurement in the frame to the differential pressure sensor, and the damper The controller unit is configured to control the air volume in the frame to a predetermined air volume while controlling the opening and closing of the blades via the actuator unit.

  According to a second aspect of the present invention, the Pitot tube has a total pressure measurement hole on the windward side at a predetermined pitch and a static pressure measurement hole on the leeward side, and is formed of a stainless steel material. 3 is characterized in that the Pitot tube is detachably mounted in the frame body.

  According to a fourth aspect of the present invention, in the kitchen VAV or CAV device according to the first aspect, the damper blade is formed of a stainless steel material, and the bearing portion for pivotally mounting the damper blade in the frame body is made of stainless steel. It is characterized in that it is formed by a bearing collar formed from a material and a sealed ball bearing.

According to the present invention, in an exhaust device required for kitchen equipment, it is possible to control while maintaining a constant and stable air volume in a duct, and to perform periodic inspection work easily and quickly. It is possible.
In addition, the main part of the apparatus can be cleaned or replaced in a state where it is removed from the frame while considering the durability of the kitchen device in the corresponding environment.

FIG. 1 is a perspective view showing a first embodiment of the apparatus of the present invention. FIG. 2 is a diagram illustrating the configuration of each part in FIG. FIG. 3 is an explanatory view showing an embodiment of the wind speed control method in the frame in FIG. FIG. 4 is a partial sectional side view of a damper blade of the damper portion. FIG. 5 shows the Pitot tube of FIGS. 1 and 2, wherein (a) is a side view, (b) is a front view of the holding bracket, Fig. 6 is an explanatory diagram showing the differential pressure / wind speed characteristics of the Pitot tube. FIG. 7 is an explanatory view showing the arrangement state of the device of the present invention in the kitchen.

FIG. 1 is a perspective view showing a first embodiment of the VAV or CAV device for kitchen exhaust according to the present invention, and FIG.

  1 and 2, reference numeral 1 denotes a kitchen exhaust VAV or CAV apparatus (hereinafter simply referred to as a kitchen exhaust apparatus) according to the present invention, which is connected to a rectangular duct body 20 as shown in FIGS. A frame 2 composed of a connection frame 21 with a kitchen side duct (not shown) and a connection frame 22 with an exhaust fan 9 (shown in FIG. 7) is pivoted into the duct body 20 of the frame 2 so as to be rotatable. The damper part 3 composed of the damper blades 30 mounted, the actuator part 4 that opens and closes the damper blades 30 of the damper part 3, and the two pitot tubes 6 are bridged in the duct body 20 of the frame body 2. A differential pressure sensor unit 5 is provided for taking out the differential pressure signals of the two pitot tubes 6 and is provided with a damper blade of the damper unit 3 while controlling the actuator unit 4 based on the differential pressure signal of the differential pressure sensor unit 5. By opening and closing 30 , And it constitutes by providing the controller unit 7 for controlling the air volume of the frame body 2 to the predetermined airflow.

Note that the controller unit 7 always maintains the specified (VAV) or constant (CAV) air volume even if the static pressure in the frame 2 changes according to the purpose of the device 1, that is, the VAV or CAV device. It is configured so that it can be controlled.
Then, the differential pressure generated in the damper is detected by the differential pressure sensor section 5 in the frame 2 (in the damper) so as to be converted into the wind speed and the air volume so that the air volume in the duct body 20 can be kept constant. It is controlled by the controller unit 7.
As an example, FIG. 3 is a block diagram showing an embodiment of the control method.

  This consists of a configuration in which the wind speed detected by the differential pressure sensor unit 5 is compared with the set wind speed, and the operation amount of the actuator unit 4 is output as a speed command from the deviation, and the actuator unit 4 Only simple comparison control can be performed by changing the energization time for turning ON. In addition, since one integrator is provided in the closed loop, the steady-state deviation of proportional control can be eliminated, and high-precision control is possible.

  Then, the current air volume is compared with the set air volume, and the actuator unit 4 is controlled to open the damper blade 30 when the current air volume is less than the set air volume, and close the damper blade 30 when the current air volume exceeds the set air volume. If the current air volume matches the set air volume, the control of the actuator unit 4 is stopped. The speed command value is the operating speed of the actuator unit 4 and can be arbitrarily changed by a parameter, and the sampling period is shortened to 1 meec so as not to cause a delay in the wind speed fed back to the control period, and a plurality of sampled values are obtained. Attenuating quantization noise and disturbance noise with a filter enables stable control from a low wind speed region.

  The configuration of the damper blade 30 of the damper section 3 can be configured by a shape corresponding to the shape of the frame body 2, for example, a square shape or a round shape configuration, and the frame body is made oil-resistant by corresponding to kitchen equipment. In consideration of the properties, it is made of stainless steel and has a structure corresponding to the surface coating.

  The same applies to the rotary shaft 31 that rotatably supports the damper blade 30 with respect to the duct body 20 of the frame body 2, and the bearing portion (not shown) has a bearing collar (made of SUS) and a sealed type. By using a ball bearing (not shown), it is configured to cope with corrosion due to oil.

Further, the open / close end portion 32 of the damper blade 30 is bonded by adhesion of oil from the kitchen by making the polymerization amount with the blade receiver 23 attached to the duct body 20 of the frame 2 as small as possible as shown in FIG. Configure so that it can be avoided.
The differential pressure sensor unit 5 is a differential pressure type wind speed sensor using a Pitot tube 6 and has a simple structure and high reliability. In addition, the differential pressure sensor unit 5 can measure the multipoint wind speed in the frame 2, so Air volume control is possible.

This has a feature that it can be implemented in all airflow directions such as upward, downward, horizontal, and diagonal.
As for the Pitot tube 6, as shown in FIG. 5 as an example, two measuring tubes 60 and 61 having a length corresponding to the width direction of the frame body 2 are fixed at the distal end portion and in the length direction. Differential pressure measurement holes (φ5mm) 62, 63 are opened at a pitch of 50mm between them, and differential pressure signal outlets 64, 65 are provided at the rear end openings to form a stainless steel material considering oil resistance. To do.

  When the frame 2 is mounted in the duct main body 20, as shown in FIG. 6, a mounting frame 66 with the duct main body 20 is provided, and the mounting frame 66 is mounted on the mounting frame 66 as shown in FIG. The mounting ports 64 and 65 of the two measuring tubes 60 and 61 are fixedly attached to the holding bracket 68 with screws 67, and the holding bracket 68 is detachably attached to the mounting frame 66 with a thumbscrew 69. It consists of.

  Thus, by mounting the mounting frame 66 while being fixedly attached to a predetermined position inside the duct 20 of the frame body 2, the Pitot tube 6 composed of the two measuring tubes 61.62 is attached to the outside of the frame body 2. That is, by removing the thumbscrew 69 that fixes the holding metal fitting 68 to the mounting frame 66 on the outside of the duct main body 20, it can be removed while being pulled out of the duct main body 20 from the duct main body 20 together with the holding metal fitting 68.

In other words, the pitot tube 6 is detachably attached from the frame 2 and can be easily maintained.
For example, it is possible not only to check for dirt such as oil, or to check when troubles occur, but also to facilitate cleaning of the pitot tube 6, and in some cases the pitot tube 6 itself can be replaced. Thus, the maintenance and inspection workability of the differential pressure sensor unit 5 can be improved.

  Further, according to the system using the Pitot tube 6 in the differential pressure sensor unit 5, as described above, the measurement hole 62 for the total pressure is set on the windward side, and the measurement hole 63 for the static pressure is set on the leeward side. The target air speed and air volume can be controlled by controlling the actuator while controlling the differential pressure signal and inputting it to the controller unit 7 (see FIG. 2).

The pressure has the following relationship:
Total pressure = Dynamic pressure + Static pressure From the above relationship, the differential pressure generated in the office or Pitot tube 6 is: Differential pressure (dynamic pressure) = Total pressure-Static pressure. This dynamic pressure is related to the wind speed as shown below. The
Wind speed = C√Differential pressure: C is a flow coefficient The characteristic of FIG. 6 can be recognized as the differential pressure-wind speed characteristic.

  In the case of a square damper or a large duct, it is necessary to measure and average the wind speed at multiple points. However, according to the first embodiment, a configuration in which a large number of differential pressure measuring holes 62 and 63 of the Pitot tube 6 are provided. Thus, the differential pressure can be averaged, and in the case of a large duct, the wind speed in the duct 20 can be easily measured by increasing the number of pitot tubes 6.

  FIG. 7 shows a configuration in which a kitchen exhaust apparatus 1 having the following configuration is applied to a kitchen exhaust system.

  In FIG. 7, reference numeral 8 denotes a kitchen, and the duct 20 of the frame 2 of the kitchen exhaust device 1 of the present invention is connected to each duct 11 of the range hood, fryer, etc. 10 of the kitchen equipment in the kitchen 8 via the connection frame 21. At the same time, by connecting the duct 90 of the exhaust fan 9 via the connection frame 22, the controller unit 7 of the kitchen exhaust device 1 is controlled by the central control panel 70 of FIG. It is possible to carry out.

DESCRIPTION OF SYMBOLS 1 Kitchen exhaust VAV or CAV apparatus 2 Frame 3 Damper part 4 Actuator part,
5 Differential pressure sensor unit 6 Pitot tube 7 Controller unit 8 Kitchen 9 Exhaust fan 10 Range hood, flyer, etc. 20 Duct body 21, 22 Connection unit 23 Blade receiver 30 Damper blade 31 Rotating shaft 32 Opening / closing end 60, 61 Measuring tube 62, 63 Measurement holes 64, 65 Differential pressure signal outlet 66 Mounting frame 67 Screw 68 Maintenance bracket 69 Thumb screw 70 Central control panel 90 Exhaust duct

Claims (4)

  A frame having a connection frame for connecting an exhaust duct and a duct for a kitchen appliance, a damper part composed of a damper blade for air volume adjustment pivotally supported in the frame, and an actuator part for opening and closing the damper blade of the damper part A differential pressure sensor unit for measuring the wind speed of the frame body, a Pitot tube for inputting a differential pressure signal obtained by multipoint wind speed measurement in the frame body to the differential pressure sensor unit, and the damper blade via the actuator unit A kitchen exhaust VAV or CAV device characterized by comprising a controller that controls opening and closing of the air flow in the frame to a predetermined air flow.   2. The kitchen exhaust VAV according to claim 1, wherein the Pitot tube is formed of a stainless steel material with a measurement hole for a total pressure on the leeward side and a measurement hole for a static pressure on the leeward side at a predetermined pitch. Or CAV device.   3. The kitchen exhaust VAV or CAV device according to claim 1, wherein the pitot tube is configured to be detachably mounted in the frame body.   The damper blade is formed of a stainless material, and the bearing portion for pivotally mounting the damper blade in the frame body is formed of a bearing collar formed of a stainless material and a sealed ball bearing. The VAV or CAV device for kitchen exhaust according to claim 1.

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