Tabletop ventilation booth

Abstract

To provide a tabletop ventilation booth which has a simple structure and is configured so that the wind speed at the suction port on the upper surface inside the booth is significantly higher than the wind speed at the suction port on the lower surface side, and which sufficiently sucks in gaseous or particulate matter to be sucked in that is diffused upward inside the booth from the suction port on the upper surface side while sufficiently reducing the blowback phenomenon during painting work, etc. [Solution] A tabletop ventilation booth configured such that, for an suction port 4 on the upper surface inside the booth, which is formed by the gap between the rearward protruding plate portion 19 of the shielding plate portion 18 provided on the front of the booth body 1 and the forward protruding plate portion 21 of the straightening plate 2 provided inside the booth, the lower edge 210a of the front edge portion 21a of the forward protruding plate portion 21 of the straightening plate 2 is positioned higher in the vertical direction of the booth body 1 than the upper edge 190a of the rearward protruding plate portion 19 of the shielding plate portion 18 of the booth body 1.

Description

[Technical Field]

[0001] The present invention relates to a tabletop ventilation booth, and more specifically, to a tabletop ventilation booth that has a simple configuration but has suction ports on both the upper and lower sides of the booth, and that sufficiently reduces the blowback phenomenon during painting work, etc., while sufficiently sucking in gaseous or particulate matter that is diffused upward within the booth through the suction port on the upper side. [Background technology]

[0002] In order to exhaust odors and dust generated from organic solvents and chemicals to the outside during painting and polishing work in model making, molding of resin pieces, chemical experiments, etc., a tabletop ventilation booth has been proposed in which an exhaust unit is installed in a box-shaped booth and the air in the work space inside the booth is sucked in by the exhaust unit.

[0003] For example, Utility Model Registration No. 3219665 (Patent Document 1) is a tabletop painting booth that can be easily installed, can exhaust mist from tabletop painting work, and does not require a filter to protect the fan. A paint booth having an exhaust fan and a booth including a work space, The booth is a roughly rectangular box-like structure with only one side open. An intake port for the exhaust fan is provided on the top surface of the booth, A substantially rectangular inclined plate is disposed inside the booth to form an exhaust intake port, The inclined plate is disposed such that a pair of two opposing sides of the substantially rectangular shape are in close contact with two side surfaces connected to the open side surface of the booth, A first side of the other pair of two sides is positioned at a position where there is a predetermined gap between the top surface of the front side of the booth and the open side when viewed from the open side, The present invention discloses a reduced pressure local forced exhaust type painting booth in which the second side is installed at an angle so that it is positioned at a predetermined gap from the underside of the rear side of the booth and the side opposite the open side when viewed from the open side.

[0004] In the painting booth of Patent Document 1, by arranging the inclined plate, upper and lower intake ports that communicate with the intake port of the exhaust fan are provided at the upper front and lower back sides of the booth, respectively, and mist and other particles generated during painting are sucked in by the exhaust fan through these upper and lower intake ports.

[0005] In the paint booth of Patent Document 1, the static pressure and air speed can be set according to the painting conditions by adjusting the gaps between the intake ports, the gap between the upper intake port and the top surface of the booth, and the gap between the lower intake port and the back surface of the booth, but depending on the settings, during painting work, etc., in the work space in front of the inclined plates acting as air straighteners within the booth, a "blowback phenomenon" occurs in which some air is not exhausted and returns to the work space from the upper or lower intake port. In the paint booth of Patent Document 1, adjusting the gaps requires re-fixing the inclined plates to change their positions or replacing them with inclined plates of different dimensions, making it difficult to reduce the blowback phenomenon.

[0006] Therefore, Utility Model Registration No. 3234017 (Patent Document 2) describes a ventilation booth that can prevent backflow even when the fan is powerful, as follows: A ventilation booth comprising a box-shaped main body having an open front, a rectifying plate provided inside the main body, and an exhaust fan mounting portion provided on the main body rearward of the rectifying plate for mounting an exhaust fan, The main body is made of a single metal main member with the bottom, back, and top surfaces made of a single plate, and a pair of metal side members that make up the sides are joined together with seams. The rectifying plate is provided between the pair of side members with a surface inclined so as to approach the bottom surface from the front side toward the rear side, The ventilation booth is disclosed to have a position adjusting means for adjusting the position of the rectifying plate so that the gap between the rectifying plate and the bottom surface can be adjusted.

[0007] However, the ventilation booth described in Patent Document 2 requires long support members on both sides of the booth as the position adjustment means, and a raised platform on the top of the booth to allow the baffle plate to be positioned upward, which increases the weight of the booth and complicates its shape. Furthermore, the ventilation booth described in Patent Document 2 is designed to suppress the blowback phenomenon by increasing the gap between the baffle plate and the bottom of the booth. This results in the air velocity in the gap between the baffle plate and the top of the booth being significantly lower than the air velocity in the gap between the baffle plate and the bottom of the booth. This creates a problem in that solvent mist, etc., that rises from an airbrush or other device and diffuses upward during painting work cannot be adequately sucked through the gap on the top. This can result in the solvent mist adhering to the top surface turning into droplets and remaining on the top surface or falling into the work space. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Utility Model Registration No. 3219665 [Patent Document 2] Utility model registration No. 3234017 Summary of the Invention [Problem to be solved by the invention]

[0009] Therefore, the object of the present invention is to provide a tabletop ventilation booth that has a simple configuration but is configured so that the wind speed at the suction port on the upper surface inside the booth is significantly faster than the wind speed at the suction port on the lower surface, and that can sufficiently suck in gaseous or particulate matter that is diffusing upward inside the booth through the suction port on the upper surface while sufficiently reducing the blow-back phenomenon during painting work, etc. [Means for solving the problem]

[0010] As a result of intensive research in light of the above-mentioned object, the inventors have discovered that, for the suction port on the upper surface inside the booth, which is formed by the gap between the rearward protruding plate portion of the shielding plate provided on the front of the booth body and the forward protruding plate portion of the straightening plate provided inside the booth, if the lower edge of the front edge of the forward protruding plate portion of the straightening plate is positioned higher in the vertical direction of the booth body than the upper edge of the rearward protruding plate portion of the shielding plate of the booth body, the wind speed at the suction port on the upper surface inside the booth will be dominant over the wind speed at the suction port on the lower surface, and a tabletop ventilation booth can be obtained which can sufficiently suck in gaseous or particulate matter that is diffused upward inside the booth from the suction port on the upper surface while sufficiently reducing the blow-back phenomenon during painting work, etc., and thereby arrive at the present invention.

[0011] That is, the tabletop ventilation booth of the present invention comprises a cubic or rectangular box-shaped booth body having a front opening that opens at least a part of the front surface and a work space provided therein; A straightening plate having a square or rectangular inclined plate portion inclined downward from the front side to the rear side inside the booth body, the left and right side surfaces of which are joined to the left and right side plate portions of the booth body, respectively; The booth includes an exhaust unit having an exhaust fan and connected to the booth body in a manner that allows communication therewith, The booth body is partitioned by the rectifying vane into the work space formed in front of the rectifying vane and a decompression space formed behind the rectifying vane, an upper end of the straightening plate is spaced apart from each of the front and upper plate portions of the booth body, thereby forming an upper suction port that connects the working space and the decompression space; and a lower end of the straightening plate is spaced apart from each of the rear and lower plate portions of the booth body, thereby forming a lower suction port that connects the working space and the decompression space; The exhaust unit is connected to at least one of the top panel, rear panel, right panel, and left panel of the booth body, which constitute the decompression space, rearward of the straightening plate so as to be able to communicate with each other, thereby drawing air into the work space through the decompression space. In this tabletop ventilation booth, A shielding plate portion is provided on the front surface of the booth body, the shielding plate portion being formed so as to be continuous with or connected to the upper surface plate portion and extending in the left-right direction of the booth body to cover an upper portion of the front surface, a rearward protruding plate portion is provided at a lower end of the shielding plate portion so as to be continuous or connected thereto, protrude toward the rear side of the booth body, and extend in the left-right direction of the booth body; a forward protruding plate portion is provided at an upper end of the straightening plate, the forward protruding plate portion being formed so as to be continuous with or connected to an upper end of the inclined plate portion, protruding toward the front side of the booth body, and extending in the left-right direction of the booth body; the forward protruding plate portion of the straightening plate is spaced apart from the upper plate portion of the booth body, and its front edge portion is formed so as to be spaced apart in the front-to-rear direction of the booth body from the rear edge portion of the rear protruding plate portion of the shielding plate portion, thereby forming the upper suction port extending in the left-to-right direction of the booth body between the rear edge portion of the rear protruding plate portion of the shielding plate portion and the front edge portion of the forward protruding plate portion of the straightening plate; The forward protruding plate portion of the straightening plate is characterized in that the lower edge of its front edge is positioned higher in the vertical direction of the booth body than the upper edge of the rear edge of the rear protruding plate portion of the shielding plate portion.

[0012] In a preferred example of the present invention, the rearward protruding plate portion of the shielding plate portion and the forward protruding plate portion of the straightening plate each protrude substantially parallel to the front-rear direction of the booth body, The distance (D1) between the rear protruding plate portion of the shielding plate portion and the upper plate portion of the booth body is within a range of 5 to 20% of the vertical length (L3) of the booth body, The distance (D3) between the upper suction ports in the front-rear direction is within a range of 5 to 15% of the length (L2) of the booth body in the front-rear direction, The vertical distance (G1) between the upper edge of the rear edge of the rear protruding plate portion of the shielding plate and the lower edge of the front edge of the forward protruding plate portion of the straightening plate is within the range of 5 to 20% of the distance (D1) between the rear protruding plate portion of the shielding plate and the upper plate portion of the booth body.

[0013] In a more preferred example of the present invention, the ratio of the front-to-rear length (D2) of the rear protruding plate portion of the shielding plate portion, the front-to-rear spacing (D3) of the upper suction port, and the front-to-rear length (D4) of the front protruding plate portion of the straightening plate is within the range of (50-80):100:(10-50), where the front-to-rear spacing (D3) of the upper suction port is 100.

[0014] In another preferred example of the present invention, a downward extending plate portion is provided at the lower end of the straightening plate, the downward extending plate portion being formed so as to be continuous with or connected to the lower end of the inclined plate portion, extending substantially parallel to the vertical direction of the booth body and extending in the left-right direction of the booth body, a lower end of the downward extending plate portion is spaced apart from a lower plate portion of the booth body, so that the lower suction port extending in the left-right direction of the booth body is formed between the lower end of the downward extending plate portion and the lower plate portion of the booth body, the vertical distance (D5) between the lower suction ports is within a range of 85 to 96% of the front-rear distance (D3) between the upper suction ports; The vertical length (D6) of the downward extending plate portion is within a range of 10 to 20% of the vertical length (L3) of the booth body, The distance (D7) between the downward extending plate portion and the rear plate portion of the booth body is within the range of 80 to 96% of the distance (D1) between the rear protruding plate portion of the shielding plate portion and the upper plate portion of the booth body.

[0015] By setting the distance D5, the length D6, and the distance D7 within the above-mentioned preferred ranges, a relatively narrow airflow path having a predetermined length is formed in a side view from the lower suction port to the area between the downward extension plate and the rear plate of the booth body. Because a relatively high static pressure is applied to this airflow path, the airflow rate through the lower suction port is suppressed. Meanwhile, the upper suction port is configured to increase the airflow rate through it, making the air velocity at the upper suction port significantly higher than that at the lower suction port. This allows for sufficient suction of gaseous or particulate matter diffusing upward within the booth through the upper suction port while sufficiently reducing the blowback phenomenon during painting work, etc.

[0016] In yet another preferred example of the present invention, the exhaust unit has, as the exhaust fan, a sirocco fan having a large number of plate-like blades arranged in a cylindrical shape, and the sirocco fan, a motor for rotating the sirocco fan, and a scroll plate for rectifying a swirling flow generated by the sirocco fan by covering an outer periphery of the sirocco fan are housed in a housing, an intake port is provided in a bottom plate of the housing opposite the circular opening of the sirocco fan, and an exhaust port to which the swirling flow is guided by the scroll plate is provided in a part of a side surface of the housing, a ring-shaped bell mouth that guides the air drawn in from the booth body to the circular opening of the sirocco fan is disposed between the bottom plate of the housing and the sirocco fan; the bell mouth has a flange portion joined to a bottom plate of the housing, and a convergent duct portion protruding from an inner edge of the flange portion toward a circular opening of the sirocco fan, In a bottom view, the circular opening of the convergent duct portion is concentrically disposed inside the circular opening of the sirocco fan.

[0017] By arranging the circular opening of the convergent duct section of the bell mouth concentrically inside the circular opening of the sirocco fan, it is possible to reduce turbulent noise and rotational noise that accompany the rotation of the sirocco fan.

[0018] In a more preferred example of the present invention, the air intake has a configuration in which a plurality of annular fan-shaped holes are arranged concentrically in the circumferential direction, and when viewed from the bottom, the circular opening of the convergent duct section is arranged concentrically inside the outer edge of an imaginary ring that connects the plurality of concentrically arranged annular fan-shaped holes in the circumferential direction.

[0019] In another more preferred example of the present invention, the scroll plate has a tongue portion located at the start of its winding, which protrudes toward the outer periphery of the sirocco fan, and the tip of the tongue portion is positioned close to the outer periphery of the sirocco fan, thereby further reducing turbulent noise and rotational noise associated with the rotation of the sirocco fan.

[0020] In yet another more preferred embodiment of the present invention, the motor is housed inside the sirocco fan. With this configuration, when the sirocco fan rotates, the motor can be cooled by the air flowing in through the circular opening of the sirocco fan. Furthermore, the exhaust unit can be made smaller.

[0021] In yet another more preferred embodiment of the present invention, the exhaust volume (m ) of the exhaust unit per hour is 3 / h) is the internal volume of the booth body (m 3 ) is within the range of 2,500 to 4,000 times.

[0022] In yet another more preferred example of the present invention, the average wind speed at the front opening of the booth body is within a range of 0.3 to 0.6 m / s, the average wind speed at the upper suction port is within a range of 1.0 to 1.4 m / s, and the average wind speed at the lower suction port is within a range of 0.05 to 0.4 m / s. [Effects of the Invention]

[0023] The tabletop ventilation booth of the present invention has suction ports on both the upper and lower sides of the booth. The suction port on the upper side is defined by the gap between the rearward-projecting plate of a shielding plate provided on the front side of the booth body and the forward-projecting plate of a straightening plate provided inside the booth. The lower edge of the front edge of the forward-projecting plate of the straightening plate is positioned vertically above the upper edge of the rearward-projecting plate of the shielding plate on the booth body. This simple configuration allows the air velocity at the upper suction port to be significantly higher than the air velocity at the lower suction port. This effectively reduces the backflow phenomenon during painting and other operations, while efficiently suctioning gaseous or particulate matter diffusing upward within the booth through the upper suction port. The tabletop ventilation booth of the present invention is useful for a variety of applications, such as painting and polishing in model making, molding resin works, and chemical experiments. [Brief explanation of the drawings]

[0024] [Figure 1] 1 is a perspective view showing a tabletop ventilation booth according to one embodiment of the present invention. FIG. [Figure 2] FIG. 2 is a front view showing the tabletop ventilation booth shown in FIG. [Figure 3] FIG. 3 is a cross-sectional view taken along line AA in FIG. 2. [Figure 4] FIG. 4 is a partially enlarged cross-sectional view showing part B of FIG. 3. [Figure 5] FIG. 4 is a partially enlarged cross-sectional view showing part C in FIG. 3. [Figure 6] FIG. 2 is an exploded perspective view showing an exhaust unit of the tabletop ventilation booth shown in FIG. 1. [Figure 7] FIG. 2 is a bottom view showing the exhaust unit of the tabletop ventilation booth shown in FIG. 1. [Figure 8] FIG. 2 is a perspective view showing the state in which the bottom panel and the second side panel of the exhaust unit of the tabletop ventilation booth shown in FIG. 1 have been removed. [Figure 9] 2 is a bottom view showing the state in which the bottom panel of the exhaust unit of the tabletop ventilation booth shown in FIG. 1 has been removed. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0025] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the accompanying drawings. However, the following description is not intended to be limiting and various modifications may be made within the scope of the technical concept of the present invention.

[0026] As shown in Figures 1 to 3, the tabletop ventilation booth of the present invention includes a box-shaped booth body 1 having an opening 10 on the front and a work space 11 provided inside, a straightening plate 2 having a square or rectangular inclined plate portion 20 that slopes downward from the front side to the rear side inside the booth body 1, and an exhaust unit 3 connected to the booth body 1 so as to be able to communicate with it.

[0027] As shown in Figure 3, the booth body 1 is divided by a rectifying vane 2 into a decompression space 12 formed behind the rectifying vane 2 and connected to an exhaust unit 3, and a work space 11 formed in front of the rectifying vane 2. The upper end of the rectifying vane 2 is spaced apart from the front face and upper panel portion 13 of the booth body 1, thereby forming an upper suction port 4 that connects the work space 11 and the decompression space 12. The lower end of the rectifying vane 2 is spaced apart from the lower panel portion 14 and rear panel portion 15 of the booth body 1, thereby forming a lower suction port 5 that connects the work space 11 and the decompression space 12.

[0028] By operating the exhaust unit 3, the pressure in the decompression space 12 becomes negative, and air is sucked in through the upper suction port 4 and the lower suction port 5, allowing gaseous or particulate matter to be sucked in, i.e., solvents volatilized by painting work, etc., and dust generated by polishing work, etc., to be discharged. The static pressure in the decompression space 12 can be adjusted by adjusting the exhaust volume of the exhaust unit 3, the size of the booth body 1, the size and configuration of the upper suction port 4 and its vicinity, and the size and configuration of the lower suction port 5 and its vicinity, etc., and therefore the air speeds at the upper suction port 4 and the lower suction port 5 can be set.

[0029] [1] Booth body 1 to 3, the booth body 1 is formed in a cubic or rectangular box shape. The booth body 1 has an opening (hereinafter referred to as the "front opening") 10 at the front that opens at least a portion of the booth body 1, and has an internal space covered by an upper panel 13, a lower panel 14, a rear panel 15, a left panel 16, and a right panel 17. The upper panel 13 and the lower panel 14 extend horizontally, while the rear panel 15, left panel 16, and right panel 17 stand vertically.

[0030] (1) Booth size The width (left-right length) L1 (see FIG. 2), depth (front-rear length) L2 (see FIG. 3), and height (vertical length) L3 (see FIG. 3) of the booth main body 1 can be set appropriately depending on the application. While not limiting, for example, the left-right length L1 is set within a range of 450 to 3,000 mm, the front-rear length L2 is set within a range of 400 to 1,500 mm, and the vertical length L3 is set within a range of 450 to 2,500 mm. Although not limiting, the ratio of the maximum length to the minimum length of the left-right length L1, the front-rear length L2, and the vertical length L3 is preferably 2.5 or less, more preferably 2.0 or less, and even more preferably 1.5 or less.

[0031] (2) Materials for the booth body There are no limitations on the material of the plates that make up the booth body 1. For example, depending on the application, desired cost, etc., the material can be selected from galvanized steel plates, aluminum plates, synthetic resin plates, wood plates, cardboard plates, etc.

[0032] (3) Front opening In the illustrated example, the front opening 10 is formed so as to open the entire area except for the portion covered by the upper shielding plate 18, so that approximately 90% of the front surface is open, but this is not limiting, and the opening ratio of the front surface may be changed depending on the type of work, the desired ventilation efficiency, the amount of solvent evaporation, the amount of dust generated, etc. For example, by installing a transparent acrylic window that slides up and down or left and right on the front surface, the opening ratio of the front surface can be changed while ensuring visibility inside.

[0033] (4) Discharge outlet placement The booth body 1 is divided by a rectifying vane 2 into a decompression space 12 formed behind the rectifying vane 2 and connected to an exhaust unit 3, and a work space 11 formed in front of the rectifying vane 2. In the illustrated example, the exhaust unit 3 is disposed above the decompression space 12, and therefore an exhaust port communicating with the exhaust unit 3 is provided in the top plate 13 of the booth body 1. However, since the exhaust unit 3 can be connected to at least one of the top plate 13, rear plate 15, left side plate 16, and right side plate 17 of the booth body 1, which constitute the decompression space 12, behind the rectifying vane 2, so that the exhaust port of the booth body 1 may be disposed appropriately depending on the location where the exhaust unit 3 is disposed.

[0034] (5) Shielding plate part 1 to 3, a shielding plate 18 is provided on the front surface of the booth body 1. The shielding plate 18 is formed so as to be continuous or connected downward from the front end of the upper surface plate 13, and extends in the left-right direction of the booth body 1 to cover the upper part of the front surface. As shown in Fig. 3, a rearward protruding plate 19 is provided on the lower end of the shielding plate 18 so as to be continuous or connected thereto, and protrudes toward the rear of the booth body 1 and extends in the left-right direction of the booth body 1. It is preferable that the rearward protruding plate 19 of the shielding plate 18 protrudes substantially parallel to the front-rear direction of the booth body 1.

[0035] When painting work is carried out using an airbrush or the like in a ventilation booth, solvent mist may fly up and adhere to the inner surface of the upper panel portion 13, turning into droplets. However, by providing a shielding plate portion 18 having a rearward protruding plate portion 19 that protrudes toward the rear of the booth body 1, droplets that adhere to the front side of the upper panel portion 13 can be guided along the inner surfaces of the shielding plate portion 18 and the rearward protruding plate portion 19 and sucked toward the decompression space 12 at the rear, thereby preventing the droplets from falling into the work space 11 or remaining on the upper panel portion 13.

[0036] In order to fully achieve the above-mentioned effects of preventing solvent droplets from falling and remaining, and to improve the wind speed of the airflow sucked from the upper suction port 4, the distance D1 (see FIG. 4) between the rearward protruding plate portion 19 of the shielding plate portion 18 and the upper plate portion 13 of the booth body 1 is preferably within a range of 5 to 20% of the vertical length L3 of the booth body 1, and more preferably within a range of 8 to 15%. Although not limited thereto, in one embodiment, when the vertical length L3 of the booth body 1 is 500 mm, the distance D1 is set to 50 mm.

[0037] (6) Other aspects A lighting unit may be provided to illuminate the work space 11. The lighting unit is installed, for example, on the underside of the rearward protruding plate portion 19 of the shielding plate portion 18. It is preferable that the lighting unit be capable of switching the illuminance, color temperature, and color rendering index in multiple stages.

[0038] [2] Current plate 1 to 3, the current plate 2 is provided inside the booth body 1 and includes a square or rectangular inclined plate portion 20 that slopes downward from the front side to the rear side, a forward protruding plate portion 21 provided at its upper end, and a downward extending plate portion 22 provided at its lower end. The left and right side surfaces of the current plate 2 are joined to the left and right side plate portions 16, 17 of the booth body 1, respectively. The upper end of the current plate 2 is spaced apart from the front and upper plate portions 13 of the booth body 1, thereby forming upper suction ports 4 that communicate between the work space 11 and the decompression space 12. The lower end of the current plate 2 is spaced apart from the lower plate portion 14 and rear plate portion 15 of the booth body 1, thereby forming lower suction ports 5 that communicate between the work space 11 and the decompression space 12.

[0039] (1) Straightening plate material There are no limitations on the material of the plate constituting the rectifying plate 2. For example, it can be selected from galvanized steel plate, aluminum plate, synthetic resin plate, wood plate, cardboard plate, etc. depending on the application, desired cost, etc.

[0040] (2) Inclined plate part 3, part of the airflow introduced into the work space 11 from the front opening 10 is guided along the inclined plate portion 20 to the upper and lower suction ports 4 and 5. In order to smoothly guide the airflow to the upper and lower suction ports 4 and 5 and ensure a sufficient work space 11, the angle of the inclined plate portion 20 with respect to the front-to-rear direction is preferably 120 to 150 degrees, and more preferably 125 to 145 degrees, although this is not a limitation.

[0041] (3) Front protruding plate part 3 and 4, the straightening plate 2 is provided with a forward protruding plate portion 21 that is formed so as to be continuous or connected to the upper end of its inclined plate portion 20, protrudes toward the front side of the booth main body 1, and extends in the left-right direction of the booth main body 1. It is preferable that the forward protruding plate portion 21 of the straightening plate 2 protrudes substantially parallel to the front-rear direction of the booth main body 1.

[0042] As shown in Figure 4, the forward protruding plate portion 21 of the straightening plate 2 is spaced apart from the upper plate portion 13 of the booth body 1, and its front edge portion 21a is formed so as to be spaced apart in the front-to-rear direction of the booth body 1 from the rear edge portion 19a of the rear protruding plate portion 19 of the shielding plate portion 18. Therefore, a rectangular upper suction port 4 extending in the left-to-right direction of the booth body 1 is formed between the rear edge portion 19a of the rear protruding plate portion 19 and the front edge portion 21a of the forward protruding plate portion 21.

[0043] As shown in FIG. 4, the forward-projecting plate portion 21 of the straightening plate 2 is formed so that the lower edge 210a of its front edge 21a is positioned higher in the vertical direction of the booth body 1 than the upper edge 190a of the rear edge 19a of the rear-projecting plate portion 19 of the shielding plate portion 18. With this configuration, as shown in FIG. 3, the airflow sucked through the upper suction port 4 is drawn toward the shielding plate portion 18 and directed toward the rear decompression space 12. This increases the wind speed of the airflow entering the upper suction port 4 from the work space 11, particularly the airflow that rises obliquely forward and upward along the inclined plate portion 20 of the straightening plate 2 and then enters the upper suction port 4. This reduces the blowback phenomenon (a phenomenon in which some air is not exhausted and returns to the work space from the suction port) that occurs during painting work using an airbrush or the like, and improves the effectiveness of sucking gaseous or particulate matter diffusing upward within the booth 1 through the upper suction port 4. Furthermore, the effectiveness of preventing solvent droplets from falling and remaining in the booth 1 is further improved.

[0044] A vertical distance G1 (FIG. 4) between the lower edge 210a of the front edge 21a of the forward protruding plate portion 21 and the upper edge 190a of the rear edge 19a of the rear protruding plate portion 19 is preferably within a range of 5 to 20%, and more preferably within a range of 5 to 15%, of the distance D1 (FIG. 4) between the rear protruding plate portion 19 of the shielding plate portion 18 and the upper surface plate portion 13 of the booth body 1. Although not limitative, in one embodiment, when the distance D1 is 50 mm, the distance G1 is 5 mm.

[0045] In order to improve the wind speed of the air sucked through the upper suction port 4, the front-to-rear distance D3 (the horizontal distance between the rear edge 19a of the rearward protruding plate portion 19 of the shielding plate portion 18 and the front edge 21a of the forward protruding plate portion 21 of the straightening plate 2) of the upper suction port 4 (see FIG. 4; hereinafter sometimes simply referred to as "distance D3") is preferably within the range of 5 to 15% of the front-to-rear length L2 of the booth main body 1, and more preferably within the range of 8 to 12%. Although not limitative, in one embodiment, when the front-to-rear length L2 of the booth main body 1 is 500 mm, the distance D3 is 50 mm.

[0046] Furthermore, to improve the wind speed of air sucked through the upper suction port 4, the ratio D2:D3:D4 of the front-to-rear direction length D2 (see FIG. 4) of the rearward protruding plate portion 19 of the shielding plate portion 18, the front-to-rear direction spacing D3 (see FIG. 4) of the upper suction port 4, and the front-to-rear direction length D4 (see FIG. 4) of the forward protruding plate portion 21 of the straightening plate 2 is preferably within the range of (50-80):100:(10-50), and more preferably within the range of (50-70):100:(15-45), where spacing D3 is 100. Although not limited thereto, in one embodiment, when spacing D3 is 50 mm, the front-to-rear direction length D2 of the rearward protruding plate portion 19 is 30 mm, and the front-to-rear direction length D4 of the forward protruding plate portion 21 is 20 mm.

[0047] (4)Downward extending plate part 1 to 3 and 5, the straightening plate 2 is provided with a downward extending plate portion 22 that is formed so as to be continuous or connected to the lower end of the inclined plate portion 20, extends downward from the inclined plate portion 20, and extends in the left-right direction of the booth body 1. The lower end of the downward extending plate portion 22 is spaced apart from each of the lower face plate portion 14 and the rear face plate portion 15 of the booth body 1, thereby forming a rectangular lower suction port 5 that communicates between the decompression space 12 and the working space 11. It is preferable that the downward extending plate portion 22 extends substantially parallel to the vertical direction of the booth body 1.

[0048] The vertical distance D5 (distance between the lower end of the downward extending plate portion 22 and the lower plate portion 14 of the booth body 1) of the lower suction port 5 (see FIG. 5; hereinafter, sometimes simply referred to as "distance D5") is preferably within the range of 85 to 96% of the front-to-rear distance D3 (see FIG. 4) of the upper suction port 4, and more preferably within the range of 85 to 94%. The vertical length D6 (FIG. 5) of the downward extending plate portion 22 is preferably within the range of 10 to 20% of the vertical length L3 of the booth body 1, and more preferably within the range of 15 to 20%. The distance D7 (see FIG. 5) between the vertically extending downward extending plate portion 22 and the rear plate portion 15 of the booth body 1 is preferably within the range of 80 to 96% of the distance D1 (see FIG. 4) between the rear protruding plate portion 19 of the shielding plate portion 18 and the upper plate portion 13 of the booth body 1, and more preferably within the range of 85 to 94%.

[0049] By setting the distance D5, the length D6, and the distance D7 within the above-mentioned preferred ranges, a relatively narrow flow path having a predetermined length is formed in a side view in the range from the lower suction port 5 to between the downward extension plate 22 and the rear plate 15 of the booth body 1, as shown in Fig. 3. A relatively high static pressure is applied to this flow path, thereby suppressing the air flow rate passing through the lower suction port 5. On the other hand, as described above, the upper suction port 4 is configured to increase the air flow rate passing therethrough, so that the air velocity at the upper suction port 4 can be made significantly higher than the air velocity at the lower suction port 5. This allows gaseous or particulate matter to be sucked in upward within the booth 1 to be sufficiently sucked in through the upper suction port 4 while sufficiently reducing the blowback phenomenon during painting work, etc.

[0050] Although not limitative, in one embodiment, if the front-to-rear spacing D3 of the upper suction port 4 is 50 mm, the vertical length L3 of the booth body 1 is 500 mm, and the spacing D1 between the rearward protruding plate portion 19 of the shielding plate portion 18 and the upper plate portion 13 of the booth body 1 is 50 mm, then the spacing D5 is 45 mm, the length D6 is 85 mm, and the spacing D7 is 45 mm.

[0051] [3] Exhaust unit By operating the exhaust unit 3, the decompression space 12 becomes a static pressure space due to negative pressure, and the air flowing in from the front opening 10 of the booth body 1 is continuously sucked in from the upper suction port 4 and the lower suction port 5, so that the gaseous or particulate matter to be sucked in can be discharged outside the room through the exhaust duct that leads the exhaust air flow outside the room.

[0052] In the illustrated example, the exhaust unit 3 is disposed above the decompression space 12, but this is not limiting, and the exhaust unit 3 can be connected to at least one of the upper panel 13, rear panel 15, left panel 16, and right panel 17 of the booth body 1, which constitute the decompression space 12, behind the straightening plate 2 so as to be able to communicate with each other. Usually, one exhaust unit 3 is required to be installed, but multiple units may be installed as necessary.

[0053] 6, the exhaust unit 3 has a configuration in which at least an exhaust fan 31 and a motor 32 that rotates the exhaust fan 31 are housed in a housing 30. In the example shown, the housing 30 has a bottom panel 30a, a top panel 30b, a first side panel 30c having an L-shaped cross section and including a front panel portion and a left side panel portion, and a second side panel 30d having an L-shaped cross section and including a back panel portion and a right side panel portion. In the illustrated example, the exhaust unit 3 has an exhaust fan 31 which is a sirocco fan 31 having a large number of plate-like blades 31a arranged in a cylindrical shape between an opposing circular upper panel 31b and a circular lower frame 31c. An air intake port 301a is provided in the bottom panel 30a which faces a circular opening 31d (see FIG. 8) of the sirocco fan 31. An exhaust port 300d is provided in the back panel portion of the second side panel 30d. A ring-shaped bell mouth 34 which guides air sucked from the booth body 1 to the circular opening 31d of the sirocco fan 31 is arranged between the bottom panel 30a and the sirocco fan 31. A scroll plate 33 which covers the outer periphery of the sirocco fan 31 and thereby rectifies the swirling flow generated by the sirocco fan 31 toward the exhaust port 300d is housed within the housing 30. A duct connector 35 which connects an exhaust duct which guides the exhaust flow to the outside of the room is provided outside the exhaust port 300d.

[0054] (1) Exhaust fan The exhaust fan 31 is not limited to a sirocco fan and may be a propeller fan, but a sirocco fan is preferable because it can easily obtain a relatively high static pressure and can reduce the size of the exhaust unit 3. In the illustrated example, a single-suction sirocco fan is used, but a double-suction sirocco fan may also be used if necessary.

[0055] (2) Bell mouth 6 to 8, bell mouth 34 has flange portion 34a joined to bottom plate 30a of housing 30, and convergent duct portion 34b protruding from the inner edge of flange portion 34a toward circular opening 31d of sirocco fan 31. As shown in FIGS. 7 to 9, diameter d1 (see FIG. 7) of the circular opening of convergent duct portion 34b is smaller than diameter d2 (see FIG. 9) of circular opening 31d of sirocco fan 31. Thus, in bottom view, the circular opening of convergent duct portion 34b is disposed concentrically inside circular opening 31d of sirocco fan 31. As a result, lower frame 31c of sirocco fan 31 is covered by bell mouth 34, and its outer periphery is further covered by housing 30. This makes it possible to reduce noise generated by turbulence in the airflow caused by the rotation of sirocco fan 31 (turbulent noise), noise generated by the rotation of sirocco fan 31, and other noises. This not only reduces stress on workers due to noise and improves work efficiency, but also contributes to consideration for neighboring houses. The diameter d1 of the circular opening of the convergent duct portion 34b may be such that the bell mouth 34 can cover the lower frame 31c of the sirocco fan 31 in a bottom view.

[0056] In the illustrated example, the air intake 301a has a configuration in which multiple circular fan-shaped holes are concentrically arranged around the motor mounting portion 300a of the bottom panel 30a. As shown in Fig. 7, the diameter d1 of the circular opening of the convergent duct portion 34b of the bellmouth 34 is smaller than the outer diameter d3 of an imaginary ring formed by connecting the multiple concentrically arranged circular fan-shaped holes 301a in the circumferential direction. In bottom view, the circular opening of the convergent duct portion 34b is concentrically arranged inside the outer periphery of the imaginary ring. Therefore, the bellmouth 34 can efficiently guide the air drawn in from the booth body 1 to the circular opening 31d of the sirocco fan 31, and can further reduce the turbulent noise and rotational noise associated with the rotation of the sirocco fan 31, as described above.

[0057] (3) Scroll plate As shown in Figures 8 and 9, scroll plate 33 has a covering portion 33a that covers most of the outer periphery of sirocco fan 31 and an exhaust portion 33b that connects covering portion 33a to exhaust port 300d. This rectifies the swirling airflow generated by sirocco fan 31 toward exhaust port 300d. As shown in Figure 9, scroll plate 33 has a tongue portion 33c located at the start of its spiral. This tongue portion 33c protrudes toward the outer periphery of sirocco fan 31 and extends vertically to cover a portion of the outer periphery of sirocco fan 31 in the axial direction of the fan. Tip 330c of tongue portion 33c is located close to the outer periphery of sirocco fan 31. This further reduces the turbulent noise and rotational noise associated with the rotation of sirocco fan 31. A distance G2 between tip 330c of tongue portion 33c and the outer edge of the rotational path of blades 31a of sirocco fan 31 is preferably 10 mm or less, and more preferably 5 mm or less.

[0058] (4) Motor placement 6 to 9, motor 32 is fixed to motor mounting section 300a on bottom plate 30a of housing 30, is housed inside sirocco fan 31, and is supported by a motor shaft at the center of top plate 31b of sirocco fan 31. By housing motor 32 inside sirocco fan 31, motor 32 can be cooled by air flowing in from circular opening 31d of sirocco fan 31 when sirocco fan 31 rotates. Furthermore, exhaust unit 3 can be made more compact.

[0059] An AC motor, a DC brushless motor, or the like that is normally used in a general sirocco fan can be used as the motor 32. If a DC brushless motor is used, it is possible to achieve even quieter operation.

[0060] (5) Exhaust unit displacement The average wind speed at the front opening 10 is preferably within the range of 0.3 to 0.6 m / s, and more preferably within the range of 0.4 to 0.6 m / s, the average wind speed at the upper suction port 4 is preferably within the range of 1.0 to 1.4 m / s, and more preferably within the range of 1.1 to 1.4 m / s, and the average wind speed at the lower suction port 5 is preferably within the range of 0.05 to 0.4 m / s, and more preferably within the range of 0.1 to 0.4 m / s. The average wind speed was determined by measuring 10 times using a thermal anemometer (model name: Anemomaster (registered trademark) Lite Model 6006-D0 (manufactured by Nippon Kanomax Co., Ltd.)) and calculating the average value.

[0061] By setting the air speeds at the front opening 10, upper suction port 4, and lower suction port 5 within the above-mentioned preferred ranges, i.e., by making the air speed at the upper suction port 4 significantly faster than the air speed at the lower suction port 5, the blowback phenomenon during painting work, etc., can be sufficiently reduced while gaseous or particulate matter that is to be sucked upward inside the booth can be sufficiently sucked in through the upper suction port 4, thereby efficiently ventilating the work space. Furthermore, the effects of preventing solvent droplets from falling and remaining behind as described above are further improved.

[0062] In order to keep the average wind speeds at the front opening 10, the upper suction port 4, and the lower suction port 5 within the above-mentioned preferred ranges, the above-mentioned interval D1, length D2, interval D3, length D4, interval D5, length D6, interval D7, and interval G1 are each set within the above-mentioned preferred ranges, and the exhaust volume (m ) per hour of the exhaust unit 3 is set to 3 / h) is calculated by dividing the internal volume of the booth body 1 (m 3 ) is preferably in the range of 2,500 to 4,000 times, and more preferably in the range of 3,000 to 4,000 times.

[0063] Although not limitative, in one embodiment, the internal volume of the booth body 1 is 0.124 m 3 (Using 0.8t galvanized steel plate, left-right length L1: 500mm, front-back length L2: 500mm, and vertical length L3: 500mm), the exhaust volume of exhaust unit 3 is 400m 3 / h(0.11m 3 / s).

[0064] (6) Other aspects If necessary, the rotation speed of the motor 32 may be made switchable in multiple stages so as to be switchable according to the desired ventilation efficiency. [Industrial Applicability]

[0065] The tabletop ventilation booth of the present invention has suction ports on both the upper and lower sides of the booth. The suction port on the upper side is defined by the gap between the rearward-projecting plate of a shielding plate provided on the front side of the booth body and the forward-projecting plate of a straightening plate provided inside the booth. The lower edge of the front edge of the forward-projecting plate of the straightening plate is positioned vertically above the upper edge of the rearward-projecting plate of the shielding plate on the booth body. This simple configuration allows the air velocity at the upper suction port to be significantly higher than the air velocity at the lower suction port. This effectively reduces the backflow phenomenon during painting and other operations, while efficiently suctioning gaseous or particulate matter diffusing upward within the booth through the upper suction port. The tabletop ventilation booth of the present invention is useful for a variety of applications, such as painting and polishing in model making, molding resin works, and chemical experiments. [Explanation of symbols]

[0066] 1. Booth body 10...Front opening 11. Work space 12. Decompression space 13...Top plate section 14...Bottom plate part 15...Rear plate part 16...Left side plate section 17...Right side plate part 18...Shielding plate part 19... Rear protruding plate part 19a... Trailing edge 190a···Upper edge 2... Rectifier plate 20... Inclined plate part 21...Front protruding plate part 21a... Leading edge 210a...lower edge 22...Downward extension plate part 3. Exhaust unit 30... Enclosure 30a...Bottom plate 300a···Motor placement section 301a···Air intake 30b...Top plate 30c First side panel 30d...Second side panel 300d···Exhaust port 31 Exhaust fan (sirocco fan) 31a···Feather 31b...Top plate 31c...Bottom frame 31d Circular opening 32 Motor 33 Scroll plate 33a... Covering part 33b Exhaust section 33c...tongue 330c...Tip 34. Bellmouth 34a Flange part 34b Converging duct section 35 Duct connection 4...Top suction port 5...Lower suction port D1: Distance between rear protruding plate and upper plate D2: Length of rearward protruding plate D3: Front-to-back distance between upper suction ports D4: Length of forward protruding plate D5: Vertical spacing of bottom suction ports D6: Length of downward extension plate D7: Distance between the downward extension plate and the rear plate d1: Diameter of the circular opening of the convergent duct d2: Diameter of the circular opening of the centrifugal fan d3: Outer diameter of the virtual ring of the intake port G1: The distance between the lower edge of the front edge of the forward protruding plate and the upper edge of the rear edge of the rear protruding plate G2: The distance between the tip of the tongue and the outer edge of the rotational path of the sirocco fan blades L1: Width of the booth body (horizontal length) L2: Depth of the booth body (front-to-back length) L3: Height of the booth body (vertical length)

Claims

1. a cubic or rectangular box-shaped booth body having a front opening that opens at least a part of the front surface and a work space provided therein; A straightening plate having a square or rectangular inclined plate portion inclined downward from the front side to the rear side inside the booth body, the left and right side surfaces of which are joined to the left and right side plate portions of the booth body, respectively; A tabletop ventilation booth including an exhaust unit having an exhaust fan and connected to the booth body in a communicable manner, The booth body is partitioned by the rectifying vane into the work space formed in front of the rectifying vane and a decompression space formed behind the rectifying vane, an upper end of the straightening plate is spaced apart from each of the front and upper plate portions of the booth body, thereby forming an upper suction port that connects the working space and the decompression space; and a lower end of the straightening plate is spaced apart from each of the rear and lower plate portions of the booth body, thereby forming a lower suction port that connects the working space and the decompression space; The exhaust unit is connected to at least one of the top panel, rear panel, right panel, and left panel of the booth body, which constitute the decompression space, rearward of the straightening plate so as to be able to communicate with each other, thereby drawing air into the work space through the decompression space. In this tabletop ventilation booth, A shielding plate portion is provided on the front surface of the booth body, the shielding plate portion being formed so as to be continuous or connected to the upper surface plate portion and extending in the left-right direction of the booth body to cover an upper portion of the front surface, a rearward protruding plate portion is provided at a lower end of the shielding plate portion so as to be continuous or connected thereto, protrude toward the rear side of the booth body, and extend in the left-right direction of the booth body; a forward protruding plate portion is provided at an upper end of the straightening plate, the forward protruding plate portion being formed so as to be continuous with or connected to an upper end of the inclined plate portion, protruding toward the front side of the booth body, and extending in the left-right direction of the booth body; the forward protruding plate portion of the straightening plate is spaced apart from the upper plate portion of the booth body, and its front edge portion is formed so as to be spaced apart in the front-to-rear direction of the booth body from the rear edge portion of the rear protruding plate portion of the shielding plate portion, thereby forming the upper suction port extending in the left-to-right direction of the booth body between the rear edge portion of the rear protruding plate portion of the shielding plate portion and the front edge portion of the forward protruding plate portion of the straightening plate; A tabletop ventilation booth characterized in that the forward protruding plate portion of the straightening plate is formed so that the lower edge of its front edge is positioned higher in the vertical direction of the booth body than the upper edge of the rear edge of the rear protruding plate portion of the shielding plate portion.

2. In the tabletop ventilation booth according to claim 1, the rearward protruding plate portion of the shielding plate and the forward protruding plate portion of the rectifying plate each protrude substantially parallel to the front-rear direction of the booth body, a distance (D1) between the rear protruding plate portion of the shielding plate portion and the upper plate portion of the booth body is within a range of 5 to 20% of a vertical length (L3) of the booth body; a longitudinal distance (D3) between the upper suction ports is within a range of 5 to 15% of a longitudinal length (L2) of the booth body; A tabletop ventilation booth characterized in that the vertical distance (G1) between the upper edge of the rear edge of the rear protruding plate portion of the shielding plate and the lower edge of the front edge of the forward protruding plate portion of the straightening plate is within the range of 5 to 20% of the distance (D1) between the rear protruding plate portion of the shielding plate and the upper plate portion of the booth body.

3. In the tabletop ventilation booth described in claim 2, the ratio of the front-to-back length (D2) of the rear protruding plate portion of the shielding plate portion, the front-to-back spacing (D3) of the upper suction port, and the front-to-back length (D4) of the front protruding plate portion of the straightening plate is within the range of (50-80):100:(10-50), where the front-to-back spacing (D3) of the upper suction port is 100.

4. In the tabletop ventilation booth according to any one of claims 1 to 3, a downward extending plate portion is provided at the lower end of the straightening plate, which is formed so as to be continuous or connected to the lower end of the inclined plate portion, extends substantially parallel to the vertical direction of the booth body, and extends in the left-right direction of the booth body, a lower end of the downward extending plate portion is spaced apart from a lower plate portion of the booth body, so that the lower suction port extending in the left-right direction of the booth body is formed between the lower end of the downward extending plate portion and the lower plate portion of the booth body, the vertical distance (D5) between the lower suction ports is within a range of 85 to 96% of the front-rear distance (D3) between the upper suction ports; The vertical length (D6) of the downward extending plate portion is within a range of 10 to 20% of the vertical length (L3) of the booth body, A tabletop ventilation booth characterized in that the distance (D7) between the downward extending plate portion and the rear plate portion of the booth body is within the range of 80 to 96% of the distance (D1) between the rear protruding plate portion of the shielding plate portion and the upper plate portion of the booth body.

5. In the tabletop ventilation booth according to claim 1, the exhaust unit has a sirocco fan as the exhaust fan, which is a cylindrically arranged sirocco fan with a large number of plate-like blades, and the sirocco fan, a motor for rotating the sirocco fan, and a scroll plate for rectifying the swirling flow generated by the sirocco fan by covering the outer periphery of the sirocco fan are housed in a housing, an intake port is provided in a bottom plate of the housing opposite the circular opening of the sirocco fan, and an exhaust port to which the swirling flow is guided by the scroll plate is provided in a part of a side surface of the housing, a ring-shaped bell mouth that guides the air drawn in from the booth body to the circular opening of the sirocco fan is disposed between the bottom plate of the housing and the sirocco fan; the bell mouth has a flange portion joined to a bottom plate of the housing, and a convergent duct portion protruding from an inner edge of the flange portion toward a circular opening of the sirocco fan, A tabletop ventilation booth characterized in that, when viewed from the bottom, the circular opening of the convergent duct section is concentrically arranged inside the circular opening of the sirocco fan.

6. 6. The tabletop ventilation booth according to claim 5, wherein the air intake has a configuration in which a plurality of circular fan-shaped holes are arranged concentrically in the circumferential direction, and when viewed from the bottom, the circular opening of the convergent duct section is arranged concentrically inside the outer edge of an imaginary ring formed by connecting the plurality of concentrically arranged circular fan-shaped holes in the circumferential direction.

7. 7. A tabletop ventilation booth according to claim 5 or 6, wherein the scroll plate has a tongue portion located at the start of its winding, the tongue portion protruding toward the outer periphery of the centrifugal fan, and the tip of the tongue portion is positioned close to the outer periphery of the centrifugal fan.

8. 6. The tabletop ventilation booth according to claim 5, wherein the motor is housed inside the sirocco fan.

9. In the tabletop ventilation booth according to claim 4, the exhaust volume (m ) per hour of the exhaust unit is ３ / h) is the internal volume of the booth body (m ３ ) in the range of 2,500 to 4,000 times.

10. 10. The tabletop ventilation booth according to claim 9, wherein the average wind speed at the front opening of the booth body is within a range of 0.3 to 0.6 m / s, the average wind speed at the upper suction port is within a range of 1.0 to 1.4 m / s, and the average wind speed at the lower suction port is within a range of 0.05 to 0.4 m / s.

Images