Oil mist removal system for factories, etc.

Abstract

To provide an oil mist removal system that can reliably remove oil mist generated in a working area while air-conditioning the working area in a factory for machining metal parts, or the like, and can contribute to energy consumption to reduce air-conditioning energy by returning return air to an air conditioner and using it as supply air again.SOLUTION: An oil mist removal system comprises: a loop duct arranged so as to form a closed loop as a whole at a setting height level in a perimeter zone of a factory, etc.; an air-conditioned air blowout part provided on a lower surface of the loop duct at a set pitch in its longitudinal direction; an air conditioner for sending conditioned air to the loop duct; and an electric precipitator provided in the air conditioner.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an oil mist removal system that removes oil mist generated in a work area of ​​a relatively large factory such as a metal parts processing factory while providing air conditioning within the work area. [Background technology]

[0002] In factories that process metal parts, large amounts of cutting oil (coolant) are used to maintain and improve processing accuracy, cool tooling, and clean and collect cutting powder. Cutting oil is used as a lubricant in industrial machinery that cuts and polishes metals, and is dispersed during the machining process of the machine tools, or vaporizes due to frictional heat, resulting in mist-like particles that become airborne. In addition to the metal cutting process, factories often also have processes for polishing smooth surfaces, and oil mist of different particle sizes is generated from all of these processes. This can have adverse effects, such as contaminating the floors, ceilings, and walls of the factory, causing worker safety issues due to slipping on the floor, odor problems, and contaminating the automatic control panels and power panels of machine tools, resulting in malfunctions.

[0003] As a reference technology before the present technology is completed, the air conditioning system and oil mist removal system will be explained based on a cross-sectional view of a metal processing factory and an explanatory diagram of the oil mist removal system shown in Figures 8 to 10. In the figure, 1 is the factory, 2 is the factory roof, 3 is the floor, 4 is a pillar, 5, 6, and 7 are various work areas set up within the factory, 8 is the exhaust space, 9 is an air conditioner set up in the exhaust space, 10 is a damper, 10a is a damper set up in the outside air intake duct, 10b is a damper set up on the outside air intake side of the air conditioner, 11 is the supply air duct, 12a and 13a are the air-conditioned air outlets, 14 is the return air duct, 15 is the return air vent, 16 is an opening, 17 is the exhaust fan, 18 is the outside air intake duct, 19 is a partition, 20 is a floor-standing air conditioner, 20a is the air-conditioned air outlet, and 21 is industrial machinery (processing machinery, manufacturing machinery, etc.).

[0004] In the example shown in the figure, conditioned air outlet section 12a, installed in the interior zone of work areas 5, 6, and 7 of factory 1, is attached so as to surround all four sides of pillar 4, and conditioned air supplied from air supply duct 11 connected to conditioned air outlet section 12a is blown out at an angle downward toward the floor using a pancar louver nozzle. This pancar louver nozzle is an outlet that is suitable for localized air conditioning, as it has easy-to-adjust direction, a strong airflow, and a long reach. On the other hand, the conditioned air blow-out section 13a attached to the pillar 4 in the perimeter zone on the periphery of the building, which faces the windows and outer walls of the building and is susceptible to changes in external conditions, blows out the conditioned air supplied from the air supply duct 11 connected to the conditioned air blow-out section 13a in a downward direction at an angle toward the floor surface. The conditioned air blowing section 12a and the conditioned air blowing section 13a are provided for each work area as required. In the example shown in Figure 10, a floor-standing air conditioner 20 is installed, and conditioned air is blown out downward at an angle toward the floor surface from a pancaruvre-type nozzle 20a provided in the floor-standing air conditioner 20. Here, the factory roof 2 is raised further to create an exhaust space 8, and an air conditioner 9 is suspended from the ceiling there to enlarge the work area 5. Using this space as exhaust space 8 and installing an exhaust fan 17 like a roof fan is a new approach that allows for the exhaust of heat buildup near the factory roof 2 and makes effective use of that space.

[0005] In a factory configured as described above, outside air supplied to air conditioner 9 from outside air intake duct 18 is temperature-adjusted by air conditioner 9, passes through air supply duct 11 as conditioned air, and is blown out at an angle downward from conditioned air outlets 12a, 13a connected to air supply duct 11, spreading the airflow over a fairly wide space with the intention of conditioning the air to a certain extent. However, the strong airflow from conditioned air outlets 12a, 13a, 20a cuts in on an area above work area 8 that is filled with oil mist that is continuously generated from industrial machinery 21 during the process, so the air is supplied into the factory while diffusing the oil mist. At the same time that the conditioned air is supplied, the oil mist-laden air that had filled the factory is collected by a hood or other device, the oil mist is removed, and the air is sent from the return air port 15 through the return air duct 14 to the air conditioner 9. To remove oil mist, 100% outside air is supplied to the factory, and the air inside the factory is sent through opening 16 to exhaust space 8 and exhausted outside the factory by exhaust fan 17, diluting the oil mist before exhaust. However, this not only leads to environmental pollution in the outside space, but also increases the amount of air conditioning energy required for temperature control, as it uses the energy from the temperature-controlled indoor air in summer and winter, compared to air conditioners that limit the amount of outside air taken in and use the return air from within the factory.

[0006] Incidentally, a prior art technique for removing oil mist has been disclosed in which, in order to improve the working environment in a kitchen, make it more comfortable, and also to save energy by adjusting the volume of air intake and exhaust, a hanging wall is installed to surround the heat-generating cooking equipment in the kitchen, forming an exhaust space, and an exhaust port is installed in the center of this exhaust space facing the ceiling or slab.The exhaust port is equipped with an exhaust duct, as well as a filter for collecting oil mist and the like, piping for cleaning the filter, a drain pipe, and other equipment, and the exhaust duct is connected to an exhaust fan to release the exhaust into the atmosphere (Patent Document 1). [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 9-243128 Summary of the Invention [Problem to be solved by the invention]

[0008] In the processing factories and the like shown as reference technologies before the completion of this invention, conditioned air was blown out at an angle from above the oil mist, dispersing the oil mist, which diluted the oil mist and made it difficult to suck it in even when collecting it with a hood or the like. Furthermore, even when sucked, the oil mist was diluted and of low concentration, so it could not be sufficiently removed using filters, etc. As a result, when air containing oil mist is returned to the air conditioner, the filters and coils installed inside the air conditioner become dirty, and the air conditioner is forced to operate with 100% outside air, with 0% returning air for cooling the factory in the summer and 0% returning air for heating in the winter, resulting in an increase in air conditioning energy consumption. Furthermore, because oil mist was not removed sufficiently, contamination by oil mist became a common occurrence, and it was necessary to take measures to prevent industrial accidents such as trips and falls due to slipping caused by oil adhering to the floor, poor visibility due to the mist, and malfunctions, electrical leakage accidents, and fires due to dirt on power panels and automatic control panels. Furthermore, the conventional cooling air supply shown in Figures 8 to 10, which is inclined toward the floor and blows out downward, is intended to be spread out, but does not reach workers who move around a little while working rather than staying in a fixed position, and the heating air supply also tends to flow above processing machines, etc., creating a poor thermal environment and making workers uncomfortable.

[0009] Furthermore, with regard to the removal of oil mist as described in Patent Document 1, an exhaust port is provided in the center of the exhaust space facing the ceiling or slab, and in addition to a filter for collecting oil mist, the exhaust port requires equipment such as piping for cleaning the filter and a drainage pipe, which creates the risk of water leakage.

[0010] The object of the present invention is to provide an oil mist removal system that can contribute to energy conservation by reducing air conditioning energy consumption by air-conditioning the work area of ​​a metal parts processing factory, returning return air containing oil mist generated in the work area to the air conditioner to reliably remove the oil mist, and then using it again as supply air. The aim is to provide a comfortable temperature environment in the factory by using temperature stratification air conditioning, and although heating in winter is done by using air conditioning for the entire factory, by blowing warm air to the feet and blocking out cold air from the surrounding area. [Means for solving the problem]

[0011] The present inventors have solved the above problems by the following means. (1) A mist collector (30) disposed near the industrial machine (21) centrally removes oil mist, The height from the floor (3) to the roof (2) Factories with heights of 2.5m or more An oil mist removal system that removes oil mist generated in the work area (5-7) while air-conditioning the work area, an air conditioner (9) provided in an exhaust space (8) in which a part of the roof (2) above the work area is raised higher than the other parts of the roof; an air supply duct (11) having one end connected to the air conditioner (9) and the other end connected to conditioned air blowout portions (12, 13); a return air duct (14) provided by connecting at least a return air port (15) or a high-induction hood (23) with a short pipe or a branch duct for taking in exhaust air from a work area, one end of which is connected to the air conditioner (9); an electrostatic precipitator (32) provided in a return air section connected to the return air duct (14) of the air conditioner (9); Equipped with The oil mist that remains after being removed by the mist collector (30) is removed by an electric dust collector (32). factory Oil mist removal system. <2> The height from the floor (3) to the roof (2) Factories with heights of 2.5m or more An oil mist removal system that removes oil mist generated in the work area (5-7) while air-conditioning the work area, A loop duct (33) is arranged in the perimeter zone of the factory to form a closed loop as a whole at a set height level, forming a level near the bottom of the duct where there is no temperature gradient from the floor surface as cold air for stratified air conditioning; conditioned air blowout portions (13b) whose upper ends are horizontal and whose cylindrical portions are inserted into holes formed at set intervals in the longitudinal direction of the loop duct (33) on the underside of the loop duct (33) so as to protrude into the loop duct (33); an air conditioner (9) provided in an exhaust space (8) in which a part of the roof (2) above the work area is raised higher than the other parts of the roof; an air supply duct (11) having one end connected to the air conditioner (9) and the other end connected to the loop duct (33); a return air duct (14) having at least a return air port (15) or a high-induction hood (23) for taking in exhaust air from a work area, one end of which is connected to the air conditioner (9); an electrostatic precipitator (32) provided in a return air section connected to the return air duct (14) of the air conditioner (9); characterized by comprising factory Oil mist removal system.

[0012] <3> The height from the floor (3) to the roof (2) Factories with heights of 2.5m or more An oil mist removal system that removes oil mist generated in the work area (5-7) while air-conditioning the work area, A loop duct (33) is arranged in the perimeter zone of the factory to form a closed loop as a whole at a set height level, forming a level near the bottom of the duct where there is no temperature gradient from the floor surface as cold air for stratified air conditioning; a loop duct (33) arranged around a pillar in the interior zone of the factory at the set height level to form a closed loop around the pillar; conditioned air blowout portions (13b) whose upper ends are horizontal and whose cylindrical portions are inserted into holes formed at set intervals in the longitudinal direction of the loop duct (33) on the underside of the loop duct (33) so as to protrude into the loop duct (33); an air conditioner (9) provided in an exhaust space (8) in which a part of the roof (2) above the work area is raised higher than the other parts of the roof; an air supply duct (11) having one end connected to the air conditioner (9) and the other end connected to the loop duct (33); a return air duct (14) having at least a return air port (15) or a high-induction hood (23) for taking in exhaust air from a work area, one end of which is connected to the air conditioner (9); an electrostatic precipitator (32) provided in a return air section connected to the return air duct (14) of the air conditioner (9); characterized by comprising factory Oil mist removal system.

[0013] <4> A loop duct (33) is arranged in the perimeter zone of the factory to form a closed loop as a whole at a set height level, forming a level near the bottom of the duct where there is no temperature gradient from the floor surface as cold air for stratified air conditioning; and conditioned air blowout portions (13b) each having a horizontal cylindrical upper end that projects into the loop duct (33) and are inserted into holes that are formed at a set pitch in the longitudinal direction of the loop duct (33) on the underside of the loop duct (33), the conditioned air blowing section (13b) comprises a cylindrical member (13c) having a male thread on its circumferential surface and an air outlet (13d) provided at the lower end of the cylindrical member (13c); The fixing member (34) has an inner circumferential surface provided with a female thread that is threadedly engaged with a male thread formed on the circumferential surface of the cylindrical member (13c), and the fixing member (34) is fixed to a hole (33a) formed in a lower surface of the loop duct (33), and the cylindrical member (13c) is screwed into the fixing member (34), as described in any one of <1> to <3>. factory Oil mist removal system. [Effects of the Invention]

[0014] The oil mist removal system for factories etc. of the present invention provides the following effects. According to the present invention, oil mist generated in metal parts processing factories and the like can be collected without being agitated, removed efficiently and reliably, and the return air can be returned to the air conditioner and used again as supply air, thereby reducing air conditioning energy and achieving energy savings.Furthermore, by providing a loop duct between the work area of ​​the factory and the roof of the factory, temperature-stratified air conditioning can be achieved with this duct as a boundary, thereby providing an air conditioning system that uses little air conditioning energy and is energy-efficient, while providing workers with a comfortable environment with fewer uncomfortable high-temperature areas in the work area. In addition, it can prevent workplace accidents such as trips and falls caused by slipping on oil that adheres to the floor due to the normalization of oil mist contamination, poor visibility due to mist, and malfunctions, electrical leakage accidents, and fires caused by contamination of power panels and automatic control panels. Furthermore, the factory is cooled comfortably using temperature stratification air conditioning, and although heating is provided to the entire factory in winter, a good temperature environment can be provided for workers by blowing warm air to the feet and blocking out cold air from the surrounding area. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a cross-sectional view of a factory or the like showing an embodiment of an oil mist removal system according to the present invention. [Figure 2] FIG. 1 is a cross-sectional view of a factory or the like showing another embodiment of the oil mist removal system according to the present invention. [Figure 3] 1 is a plan view of a factory or the like showing an embodiment of an oil mist removal system according to the present invention. [Figure 4] 1 is a cross-sectional view illustrating an embodiment of an oil mist removal system according to the present invention, showing an air conditioning air outlet in a factory or the like. [Figure 5] FIG. 1 is a diagram showing experimental data showing airflow and wind speed distribution during summer cooling in an embodiment of the oil mist removal system according to the present invention. [Figure 6] 1 is a diagram showing the gradient of indoor temperature during cooling in summer in an embodiment of the oil mist removal system according to the present invention. [Figure 7] FIG. 1 shows the results of a nanoparticle collection test using an electric dust collector (built into an air conditioner) in an embodiment of the oil mist removal system according to the present invention. [Figure 8] Cross-section of a conventional factory [Figure 9] Illustration of a conventional oil mist removal system used in factories, etc. [Figure 10] Another explanatory diagram of a conventional oil mist removal system for factories, etc.

[0016] An example of an embodiment of the oil mist removal system for factories etc. according to the present invention will be described below in comparison with a conventional oil mist removal system for factories etc. 1 to 4 show an embodiment of the oil mist removal system of the present invention for use in a metal processing factory, etc. In the figures, the same components as those in Fig. 8 are designated by the same reference numerals, and detailed description thereof will be omitted. In Figures 1 to 4, 1 is a factory, 2 is the roof of the factory, 3 is a floor, 4 is a pillar, 5, 6, and 7 are various work areas provided in the factory, 8 is an exhaust space, 9 is an air conditioner provided in the exhaust space, 10 is a damper, 10a is a damper provided in the outside air introduction duct, 10b is a damper provided on the outside air intake side of the air conditioner, 11 is an intake air duct, 12b and 13b are conditioned air blowing parts, 14 is a return air duct, and 15 is a return air duct. 1 is an air vent, 16 is an opening, 17 is an exhaust fan, 18 is an outside air intake duct, 19 is a partition, 21 is industrial machinery (processing machinery, manufacturing machinery, etc.), 23 is a high-induction hood, 24 is a partition, 25 is a hood, 26 is an exhaust duct connected to the hood, 27 is a hanging film, 30 is a mist collector, 31 is a temperature sensor, 32 is an electric dust collector (air conditioner built-in type), 33 is a loop duct, and 34 is a curtain.

[0017] Conditioned air blowout section 12b is an air-conditioned air blowout section provided in the interior zone of work areas 5, 6, and 7 in factory 1, and is attached so as to surround all four sides of pillar 4. It includes loop duct 33 arranged to form a closed loop around pillar 4 at a set height level that forms a level near the bottom of the duct that does not create a temperature gradient from the floor surface for stratified air conditioning, and is provided with conditioned air blowout section 12b whose cylindrical portion with a horizontal upper end protrudes and is inserted into loop duct 33 on its underside, through holes 33a that are opened at a set pitch in the longitudinal direction of loop duct 33. As a result, conditioned air supplied from air supply duct 11 connected to conditioned air blowout section 12b is blown out directly downward toward the floor surface.

[0018] On the other hand, the conditioned air blowing section 13b is an conditioned air blowing section provided in a loop duct 33 in a loop shape throughout the factory 1 along the wall that corresponds to the perimeter zone of the factory 1. As shown in FIG. 4, the conditioned air blowing section 13b is composed of a cylindrical member 13c having a male thread on the circumferential surface, and an outlet 13d provided at the lower end of the cylindrical member 13c. A fixing member 34, whose inner surface is provided with a female thread that screws into the male thread, is fixed to a hole 33a drilled in the underside of the loop duct 33, and the cylindrical member 13c is screwed into the fixing member 34 to join the loop duct 33 and the conditioned air blowing section 13b. In this way, by configuring the insertion length S of the upper end opening of the cylindrical member 13c that constitutes the conditioned air blowing section 13b, which is parallel to the central axis of the loop duct 33 in the ventilation direction, into the loop duct 33 to be freely adjustable, the conditioned air sent into the loop duct 33 by the air conditioner 9 is blown out as a downward flow from the blowing outlet 13d provided at the lower end of the cylindrical member 13c.

[0019] The positions (height) at which conditioned air blowing section 12b and conditioned air blowing section 13b are installed can be determined appropriately depending on the size of the factory or the like, the size of the work area provided within the factory, and the desired work environment.

[0020] An embodiment in which the oil mist removal system for use in a factory or the like according to the present invention is combined with an air conditioning system for the factory configured as described above will be described in detail below. The outside air supplied to the air conditioner 9 from the outside air intake duct 18 is temperature-adjusted by the air conditioner 9 and sent as conditioned air to the air supply duct 11. The conditioned air sent from the air supply duct 11 is then blown directly downward toward the floor from the air-conditioned air blowout section 12b connected to the air supply duct 11 and the air outlet 13d of the air-conditioned air blowout section 13b provided in the loop duct 33, and is supplied into the factory.

[0021] At this time, the conditioned air blown out directly downwards towards the floor from conditioned air outlet 12b and outlet 13d of conditioned air outlet 13b reaches the floor and does not flow in the direction of pillar 4 because the pressure increases. Instead, part of the airflow flows along the floor due to the Coanda effect, while other parts of the airflow hit the floor and are pushed slightly upward near the floor, forming temperature stratification throughout the work area, and the air slowly rises to the different temperature layers that form the stratification, carrying small particles of oil mist with it. Within the factory, a large number of industrial machines 21 are placed, each generating oil mist. As a measure to address the source of oil mist near the industrial machines 21, large particle diameter oil mist is removed by a mist collector 30, such as a centrifugal separator (cyclone type), inertial collision type (disk rotation type), or particle condensation type. Small particle diameter oil mist that is not removed by the mist collector 30 rises upward due to the formed thermal stratification. The rising air is finally sucked into the return air vent 15 and the high-induction hood 23, passes through the return air duct 14, and is sent to the air conditioner 9 through a passage opened by the damper 10 installed in the return air duct 14. The air is then passed through an electric dust collector 32 built into the air conditioner 9 to remove oil mist from the return air, and is then sent from the air conditioner 9 to the supply air duct 11, where it is supplied again into the work area of ​​the factory 1.

[0022] In this way, the conditioned air blown out from conditioned air outlets 12b and 13b is configured to be blown straight down towards the floor, so the conditioned air blown out above the work area filled with oil mist does not flow and does not diffuse the oil mist, and since the oil mist contained in the return air is removed by electrostatic precipitator 32, the oil mist does not condense.

[0023] In this embodiment, 70% of the return air was sent to the air conditioner by opening and closing the damper 10, and the required amount of conditioned air was supplied to the factory after removing oil mist from the factory at a ratio of 70% return air and 30% outside air.

[0024] Based on FIG. 1, the removal of oil mist will be explained for each of the work areas 5, 6, and 7 provided in the factory 1. In the work area 5, large oil mist particles are removed from the return air by a mist collector 30, and the return air passes through a high-induction hood 23 and a return air duct 14, then passes through a passage opened by a damper 10 installed in the return air duct 14, and the small oil mist particles contained in the return air are removed by an electric dust collector 32 built into the air conditioner 9, and the return air is then supplied from the air conditioner 9 through an intake air duct 11 into the factory room.

[0025] In the work area 6, the industrial machine 21 is enclosed by a partition 24, and a hood 25 with a hanging film 27 around it is provided above the industrial machine 21, thereby sealing the area around the industrial machine 21. The return air containing oil mist then passes through exhaust duct 26 connected to hood 25 and return air duct 14. After that, it passes through a passage opened by damper 10 provided in return air duct 14, and the oil mist contained in the return air is removed by electrostatic precipitator 32 built into air conditioner 9. The return air is then supplied from air conditioner 9 through intake air duct 11 into the work area of ​​factory 1.

[0026] In the work area 7, industrial machinery 21 is also enclosed by a partition 24. Large particle oil mist is removed from the return air by a mist collector 30, and the return air passes through a high-induction hood 23 and a return air duct 14, passing through a passage opened by a damper 10 provided in the return air duct 14, where small particle oil mist is removed by an electric dust collector 32 built into the air conditioner 9. The return air is then supplied from the air conditioner 9 through an intake air duct 11 into the work area of ​​the factory 1. In FIG. 2, the conditioned air blowout section 12b attached to the pillar 4 so as to surround the four sides thereof is surrounded by a curtain 34 to provide a clean zone 40.

[0027] FIG. 3 shows an example of a processing factory using the oil mist removal system according to the embodiment of the present invention. In FIG. 3, (A) is a plan view of the factory, (B) is a cross-sectional view of (A) in the X direction, and (c) is a cross-sectional view of (A) in the Y direction. As shown in Figure 3, various work areas (a, b, n) are set up within Factory 1 for different purposes, and air conditioning and oil mist removal are controlled. In an embodiment of the present invention, the loop duct (33) is disposed so as to form a closed loop as a whole at a set height (H) level from the bottom surface of the loop duct (33) to the floor surface in the perimeter zone, which is an area where heat load is transmitted from outside the factory, and conditioned air blowing sections 13b are inserted into the bottom surface of the loop duct (33) at a set pitch in the longitudinal direction by inserting cylindrical members 13c (see Figure 4) of the conditioned air blowing sections 13b. The set pitch P is set appropriately depending on the overall length of the loop duct 33, the area in the factory where it is installed, and other conditions. Although not shown in FIG. 3, in the interior zone of the factory 1, conditioned air blowing sections 12b are attached to surround the four sides of the pillar 4 as needed (see FIG. 1).

[0028] Next, the operation of the above embodiment will be explained in the case of use in summer. When conditioned air (air for heating and cooling) is sent from the air conditioner 9 through the air supply duct 11 into the loop duct 33, the air is inserted into holes formed at a set pitch in the longitudinal direction of the underside of the loop duct 33 with a cylindrical portion with a horizontal upper end protruding into the loop duct 33, causing the high-speed airflow with dynamic pressure in the center of the loop duct 33 to regain static pressure, and the air is blown out uniformly downward at high speed (2 m / s to 7 m / s) from each of the conditioned air outlets 13b arranged at a set pitch. The air is then blown out as a downward flow from outlets 13d provided at the lower end of cylindrical members 13c of the conditioned air outlet section 13b. If the insertion length S of the cylindrical member 13c of the conditioned air blowing section 13b is set to 0 cm, only the air near its lower surface in the loop duct 33 will flow to the conditioned air blowing section 13b. The air flow above the lower surface of the loop duct 33 passes through the air conditioned air blowing section 13b with almost no effect from the air conditioned air blowing section 13b. This reduces the static pressure within the loop duct 33, weakens the air blown out from the air conditioned air blowing section 13b, and reduces the blown air volume. On the other hand, if the insertion length S of the cylindrical member 13c of the conditioned air blowing section 13b is set to greater than 0 cm, the air flowing in the loop duct 33 will be affected by the insertion portion of the cylindrical member 13c. As a result, the air flowing upstream is lifted and flows into the cylindrical member 13c, generating a vortex downstream, which creates significant flow resistance.

[0029] As a result, at the position of each conditioned air blowing section 13b along the entire length of loop duct 33, the conversion from dynamic pressure, which is the kinetic energy of the air flowing within loop duct 33, to static pressure progresses, and static pressure that pushes a predetermined amount of air from each conditioned air blowing section 13b in a direction perpendicular to the longitudinal direction of loop duct 33 is obtained at the upper end opening position of the cylindrical member 13c of each conditioned air blowing section 13b, which is parallel to the central axis in the air flow direction of loop duct 33, resulting in a uniform amount of air being blown out from each conditioned air blowing section 13b.

[0030] Incidentally, the wind speed distribution within the loop duct 33, in a cross section perpendicular to the direction in which the air travels, tends to be slower near the top and bottom surfaces and left and right side surfaces that make up the loop duct 33 due to frictional resistance of the inner surface, and the wind speed tends to be almost zero just near the inner surface of the loop duct 33 and increase up to the center of the interior of the loop duct 33.Therefore, the insertion length S should be longer than 0 cm and less than 1 / 2 of the internal height of the loop duct 33 (the distance to the center line).

[0031] An experiment was conducted on a loop duct 33 fabricated as an experimental device, with a rectangular cross section measuring 70 cm wide and 40 cm high, and a total length of approximately 70 m. The loop duct 33 had an inner diameter of φ60 mm, the set pitch P was 2000 mm, and the insertion length S of the cylindrical member 13c of the air-conditioned air blowing section 13b was set to 10 cm and 0 cm to measure the blowing volume of each air-conditioned air blowing section 13b. It was confirmed that when the insertion length S was 0 cm, there was variation in the blowing volume from each outlet 13d, whereas when the insertion length S was 10 cm, there was almost no variation in the blowing volume, and it was a substantially constant value. The air flow rate from the air conditioner 9 of the experimental equipment was 9800 m 3 / h], the amount of air blown out from each conditioned air blowing section 13b is approximately 200 [m 3 / h], and the air flow rate from the air conditioner 9 is 4900 [m 3 / h], the amount of air blown out from each conditioned air blowing section 13b is approximately 100 [m 3 / h]. Furthermore, the inner diameter of cylindrical member 13c of conditioned air blowing section 13b is set to φ60 to 150 mm, and the air speed passing through cylindrical member 13c is set to 2 to 7 m / s. Therefore, if the height of the lower end of conditioned air blowing section 13b is set to 2.3 m or more from the floor, the air speed can be set to less than 0.5 m / s at a height of 1.1 to 1.2 m, where a worker is seated. Therefore, during summer cooling, even directly below the air blowing nozzle, there is almost no discomfort caused by the airflow touching the skin, or the so-called draft feeling. Moreover, the slow airflow formed along the floor creates temperature stratification.

[0032] FIG. 5 is a diagram showing experimental data showing airflow and wind speed distribution during cooling in summer in an embodiment of the oil mist removal system according to the present invention. The set height H to the bottom surface of the loop duct 33 is H=5 [m], and the blowout amount from the conditioned air blowout portion 13b is approximately 200 [m 3 / h], the wind speed at a position about 1000 [mm] below the lower surface of the loop duct 33 (a height position of 4 [m] from the floor surface) is approximately 2.73 [m / s]. On the other hand, even directly below the conditioned air blow-out section 13b, the wind speed at a height of 1.5 m above the floor is approximately 0.29 m / s. At a height of 0.5 m above the floor, the wind speed is approximately 0.26 m / s, meaning there is almost no discomfort caused by the airflow touching the skin, a so-called draft feeling. Furthermore, a slow airflow with a wind speed of approximately 0.08 m / s is formed along the floor surface (the horizontal axis in the figure), resulting in temperature stratification.

[0033] As a result, although this is an example of a different ceiling height, the indoor temperature distribution during summer cooling is as shown in Figure 6, where only the work area on the lower floor is cooled and the unoccupied area on the upper floor is not cooled, resulting in a significant energy saving effect. Note that the data in Figure 5 is for H=5m, but if H is in the range of 2.5 to 6m, the airflow and wind speed distribution during summer cooling will show similar trends as described above.

[0034] Furthermore, in the case of a system in which cool air is supplied as a downward flow from outlets 13d of conditioned air outlet section 13b on the underside of loop duct 33 installed at a height of 2.5 to 6 m during summer cooling, the cool air supplied from outlets 13d of conditioned air outlet section 13b actively tries to mix and diffuse throughout the room after descending about 2 m, making it possible to cool the room from directly below loop duct 33. Furthermore, the air flow that has flowed to the vicinity of the floor is attracted to the floor by the Coanda effect, and then extends horizontally, transporting the cool air horizontally, and the cool air accumulates up to the height of loop duct 33. That is, because the cooling zone depends on the height of loop duct 33, even if the return air vent that mechanically draws air into the air conditioner 9 is lowered to the height of loop duct 33, the indoor temperature remains approximately constant up to the height of 3 m where loop duct 33 is installed, as shown in Figure 6, and a good vertical temperature gradient is obtained. As a result, the upper hot air layer is not drawn in through the return air vent, making it possible to significantly reduce the energy consumption of the air conditioner 9.

[0035] FIG. 7 is a diagram showing the results of a nanoparticle collection test using an electric dust collector (air conditioner built-in type) used in an embodiment of the present invention. In the figure, the vertical axis represents collection efficiency (%) and the horizontal axis represents particle size Dp (nm). For the measurements, a light scattering particle counter (Palas Aerosol Spectrometer Welas2000) and an electrostatic mobility particle counter (TSI Real-time Self-Exhaust Particle Analyzer EEPS Model 3090) were used to measure the mass concentration of each particle size at the inlet and outlet of the electrostatic precipitator (built-in to air conditioner), and the collection efficiency was calculated from the ratio to determine the collection performance for nanoparticles. It is known that the haze generated in factories is caused by particles with a diameter of 60 to 70 nm. As shown in Figure 7, it is clear that the electrostatic precipitator (built-in air conditioner) 32 can effectively remove particles of 60 to 70 nm size as well as particles larger than that.

[0036] According to an embodiment of the present invention, near the walls of factory 1, conditioned air sent through air supply duct 11 from air conditioner 9 is blown straight down towards the floor from air outlet 13d of conditioned air blowing section 13b provided in loop duct 33 which is arranged to form a closed loop as a whole at a set height H along the factory's windows, and in a work area etc. provided in the interior zone inside the factory, from air conditioned air blowing section 12b attached so as to surround the four sides of pillar 4. The blown-out conditioned air then reaches the floor, where part of the airflow moves along the floor due to the Coanda effect, while other parts hit the floor and form a push-out flow slightly above the floor, creating thermal stratification, allowing the conditioned air to reach workers sufficiently, ensuring a stable thermal environment for workers and creating a comfortable factory environment. Of the oil mist generated near industrial machinery 21, large particles are removed by mist collector 30 installed beside industrial machinery 21, while the remaining small oil mist rides on the thermally stratified airflow and rises upward, passing through return air duct 14 from return air port 15 and being sucked up by the air conditioner installed in exhaust space 8, where it can be efficiently removed by electrostatic precipitator (built-in to air conditioner) 32.

[0037] In addition to eliminating the poor visibility caused by oil mist haze, it can also improve the working environment within factories, which is prone to industrial accidents such as trips and falls caused by slipping on oil on the floor, and reduce malfunctions, electrical leakage accidents, and fires caused by dirty power panels and automatic control panels. The oil mist that is generated near factory machinery and has a large particle size is generated in large quantities by mass, so a large number of relatively inexpensive mist collectors can be placed according to the source of the generation, such as factory machinery, while the oil mist that is generated in small quantities by mass and moves upward due to the remaining thermal stratification is removed intensively using a relatively expensive electrostatic precipitator built into the air conditioner, making it possible to create a cost-effective oil mist removal system.

[0038] Furthermore, according to the embodiment of the present invention, in contrast to an air conditioning method that takes in a large amount of outside air and discharges oil mist outside the factory due to a dilution effect, which poses the risk of environmental pollution while mitigating the impact of oil mist inside the factory, the oil mist is removed using mist collectors near industrial machines and an electric dust collector built into the air conditioner that returns the air from the factory, and the energy used to control the temperature of the indoor air in summer and winter is used to reduce the amount of outside air taken in and to use the return air from the factory, thereby suppressing the increase in air conditioning energy required for temperature control.

[0039] Furthermore, according to the embodiment of the present invention, oil mist can be removed by an electric dust collector built into the air conditioner, so even if air containing oil mist is returned to the air conditioner, dirt on the filters and coils installed inside the air conditioner is significantly reduced. [Industrial Applicability]

[0040] The present invention can be effectively used in factories that process metal parts, as well as in food processing factories that process food using fryers. [Explanation of symbols]

[0041] 1. Factory 2. Roof 3 beds 4 pillars 5, 6, 7 Working Areas 8 Exhaust space 9 Air conditioner 10 Damper 11 Air supply duct 12a, 12b Air conditioning air outlet section 13a, 13b Air conditioning air outlet section 14 Return air duct 15 Return air port 16 Opening 17 Exhaust fan 18 Outside air intake duct 19 Partitions 20 Floor-standing air conditioner 21 Industrial Machinery 23 Highly attractive food 24 partitions 25 Food 26 Exhaust duct 27 Dripping membrane 30 Mist Collector 31 Temperature Sensor 32 Electrostatic precipitator (air conditioner built-in type) 33 Loop Duct 34 Curtains

Claims

1. A mist collector (30) disposed near the industrial machine (21) centrally removes oil mist, An oil mist removal system for removing oil mist generated in a work area (5-7) of a factory, the work area having a height of 2.5 m or more from a floor (3) to a roof (2), while air conditioning the work area, an air conditioner (9) provided in an exhaust space (8) in which a part of the roof (2) above the work area is raised higher than the other parts of the roof; an air supply duct (11) connected at one end to the air conditioner (9) and at the other end to conditioned air blow-out sections (12, 13); a return air duct (14) provided by connecting at least a return air port (15) or a high-induction hood (23) with a short pipe or a branch duct for taking in exhaust air from a work area, one end of which is connected to the air conditioner (9); an electrostatic precipitator (32) provided in a return air section connected to the return air duct (14) of the air conditioner (9); Equipped with An oil mist removal system for use in a factory, characterized in that any remaining oil mist that cannot be removed by the mist collector (30) is removed by an electric dust collector (32).

2. An oil mist removal system for removing oil mist generated in a work area (5-7) of a factory, the work area having a height of 2.5 m or more from a floor (3) to a roof (2), while air conditioning the work area, A loop duct (33) is arranged in a perimeter zone of a factory so as to form a closed loop as a whole at a set height level, forming a level near the bottom of the duct where there is no temperature gradient from the floor surface as cool air for stratified air conditioning; a conditioned air blowing section (13b) whose upper end is horizontal and whose cylindrical section is inserted into the loop duct (33) so as to protrude into holes formed at a set pitch in the longitudinal direction of the loop duct (33) on the underside of the loop duct (33); an air conditioner (9) provided in an exhaust space (8) in which a part of the roof (2) above the work area is raised higher than the other parts of the roof; an air supply duct (11) connected at one end to the air conditioner (9) and at the other end to the loop duct (33); a return air duct (14) having at least a return air port (15) or a high-induction hood (23) for taking in exhaust air from a work area, one end of which is connected to the air conditioner (9); an electrostatic precipitator (32) provided in a return air section connected to the return air duct (14) of the air conditioner (9); An oil mist removal system for a factory, comprising:

3. An oil mist removal system for removing oil mist generated in a work area (5-7) of a factory, the work area having a height of 2.5 m or more from a floor (3) to a roof (2), while air conditioning the work area, A loop duct (33) is arranged in a perimeter zone of a factory so as to form a closed loop as a whole at a set height level, forming a level near the bottom of the duct where there is no temperature gradient from the floor surface as cool air for stratified air conditioning; a loop duct (33) arranged around a pillar in the interior zone of the factory at the set height level to form a closed loop around the pillar; a conditioned air blowing section (13b) whose upper end is horizontal and whose cylindrical section is inserted into the loop duct (33) so as to protrude into holes formed at a set pitch in the longitudinal direction of the loop duct (33) on the underside of the loop duct (33); an air conditioner (9) provided in an exhaust space (8) in which a part of the roof (2) above the work area is raised higher than the other parts of the roof; an air supply duct (11) connected at one end to the air conditioner (9) and at the other end to the loop duct (33); a return air duct (14) having at least a return air port (15) or a high-induction hood (23) for taking in exhaust air from a work area, one end of which is connected to the air conditioner (9); an electrostatic precipitator (32) provided in a return air section connected to the return air duct (14) of the air conditioner (9); An oil mist removal system for a factory, comprising:

4. A loop duct (33) arranged in a perimeter zone of a factory to form a closed loop as a whole at a set height level, forming a level near the bottom of the duct where there is no temperature gradient from the floor as cold air for stratified air conditioning; and an air-conditioning air blowing section (13b) having a cylindrical portion with a horizontal upper end that is inserted into holes that are opened at a set pitch in the longitudinal direction of the loop duct (33) on the lower surface of the loop duct (33), with the cylindrical portion protruding into the loop duct (33), the conditioned air blowing section (13b) comprises a cylindrical member (13c) having a male thread on its circumferential surface and an air outlet (13d) provided at the lower end of the cylindrical member (13c); 4. An oil mist removal system for use in a factory according to claim 1, wherein a fixing member (34) having an internal thread on its inner circumferential surface that screws together with an external thread on the circumferential surface of the cylindrical member (13c) is fixed to a hole (33a) drilled in the underside of the loop duct (33), and the cylindrical member (13c) is screwed into the fixing member (34).

Images