Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
  • B05B1/00—Nozzles, spray heads or other outlets, with or without auxiliary devices such as valves, heating means
  • B05B1/005—Nozzles or other outlets specially adapted for discharging one or more gases
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
  • B05B1/00—Nozzles, spray heads or other outlets, with or without auxiliary devices such as valves, heating means
  • B05B1/14—Nozzles, spray heads or other outlets, with or without auxiliary devices such as valves, heating means with multiple outlet openings; with strainers in or outside the outlet opening

Definitions

• the present invention concerns a blowing nozzle for a highly pressurized gaseous fluid comprising at least two narrow exhaust passages having a width insignificantly larger than the size of particles, occurring in said fluid.
• Blowing nozzles are used for various industrial pur ⁇ poses, e.g. to blow away cuttings from a boring and other debris from a workpiece, to cool during welding or other kind of heat generating work, as exhausts from pneumatic machines or for drying of paint.
• Noise reducing blowing nozzles are known, e.g. from SE 7806883-0, which has several small circular passages. These small passages must be drilled with a very high degree of precision, in order to achieve the desired noise reducing effect. Because of the necessity for a high degree of pre ⁇ cision these nozzles are comperatively expensive to manu ⁇ facture. At the same time the blowing force possible with one of these nozzles is limited, which means that several nozzles must be mounted in parallel in order to reach a de ⁇ sired large blowing force. This means that these noise- reducing blowing nozzles in many cases are a very expensive solution to the noise problem.
• the object of the present invention is therefore to produce a cheap and efficient nozzle with noise reducing properties, and by which it is possible to reach a conside ⁇ rably larger blowing force for a given frontal area, com ⁇ pared with corresponding known blowing nozzles.
• the invention is characterized in that the exhaust passages are slit-formed, each having a length, no more than ten times the average width of each slit, and that they ex ⁇ tend in parallel or radially over the end surface of the nozzle . , in a projection perpendicular to its longitudinal axis.
• the depth of each slit-formed exhaust passage is at last five to ten times the length of said slit.
• Preferably several exhaust passages are formed in parallel with the longitudinal axis of the nozzle in a cen ⁇ tral body, which is surrounded by a casing.
• the nozzle has a circular front with exhaust passages radially arranged concentrically around a common longitudinal axis, wherein the slit-formed exhaust passages are arranged with a minimum individual distance (distance between centres) of three times the slit width.
• the passages are diverging radially outwards to the surrounding casing.
• the central body protrudes from the casing in order to increase coejection of atmospheric air surrounding the nozzle.
• a nozzle having a rectangular front and parallel exhaust passages preferably has a distance between passages that is at least three times the square root from the product of slit length multiplied by the slit width.
• Fig. 1 is an end view of a circular nozzle according to a first embodiment of the invention.
• Fig. 2 is a section along line II-II in Fig. 1 with left and right half of the figure showing two different examples of the invention
• Fig. 3 is an end view of a second embodiment of a circular nozzle
• Fig. 4 is an end view of a rectangular nozzle according to the invention
• Fig. 5 is a section along line VI-VI in Fig. 7, which is a side view of another embodiment of the invention, shown in 5:1 scale
• Fig. 8 is a section along line VIII-VIII in Fig. 7.
• the nozzles comprise a central body 10 with longitudinal parallel slits and is surrounded by a thin wall casing 11.
• the slits form narrow exhaust passages 12 together with the casing 11, wherein the passages have a length L no more than ten times the width d of the slits and a depth t at least five to ten times the length of the slits.
• the f max has proven to be proportional to the square root from the product of slit length L multiplied by the slit width, up to very high factors L/d. It will, however, not be practical to use larger values for L/d than 10. (Note that f will only be proportional to d for values of L/d ?*- 100 and higher. But this is of no concern in the field of blowing nozzles.)
• the maximum frequence should be close to or even above 15 000 Hz, i.e. above normal upper limit for human hearing. For this reason the exhaust passages 12 are. as narrow as possible, without risk for clogging by debris in the exhaust air. At the same time sufficient outlet area is achieved by the number of exhaust passages, which number can be varied depending on the needs.
• Fig. 3 shows a variant of the nozzle according to the invention, wherein the slits have two different lengths L, and 2 respectively.
• This embodiment enables a larger blow ⁇ ing capacity for a given frontal area. This arrangement, however, results in a slightly higher sound level.
• Figs. 4 and 5 show a rectangular nozzle according to the invention having four exhaust passages 12 extending through a central body 10, which is surrounded by a four-sided casing 11.
• the exhaust passages are narrow and slit-formed. The distance between these are at least three times the square root from the product of slit length L multiplied by the slit width d.
• the exhaust passages 12 can be cut into the central body from both the long sides, so that the body is maintained in one piece, which can be pushed axially into the casing 11.
• the slit length L is no more than ten times the slit width d and the slit depth t is at least five to ten times the slit length L.
• the passages can also be made converging in the direction of the gas stream towards the nozzle front.
• Figs. 6, 7 and 8 show a variant of the invention wherein the exhaust openings 12, as seen in their longitudinal di ⁇ rection, diverge radially towards the surrounding casing 11.
• This embodiment is especially preferable when producing very narrow blowing nozzles having a frontal diameter of about 5 mm.
• the exhaust passages can reach further in towards the centre of the nozzle since they di ⁇ verge as mentioned above, without getting into conflict with the condition that the smallest distance between adjacent passages must be three times the width of the slit-formed passages, which contributes to a further increased blowing force for any given nozzle frontal area. If the nozzle is pointed like in Figs. 7 and 8 its accessibility is enhanced and it can be used to clean very small drill holes.
• the proportionally large depth of the slit-formed passages at the nozzles according to the invention prevents this back flow and therefore contributes to the lowered noise level.
• the central body can be moulded, cut or extruded at a comparatively low cost.

Landscapes

• Nozzles (AREA)
• Physical Or Chemical Processes And Apparatus (AREA)
• Exhaust Silencers (AREA)
• Filtering Of Dispersed Particles In Gases (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (1)

Family

ID=20360489

Family Applications (1)

Country Status (6)

Cited By (1)

Families Citing this family (7)

Citations (4)

Family Cites Families (7)

• 1985
  • 1985-06-07 SE SE8502825A patent/SE448828B/sv not_active IP Right Cessation
• 1986
  • 1986-06-05 EP EP86903683A patent/EP0224555B1/en not_active Expired
  • 1986-06-05 JP JP61503168A patent/JPH0622707B2/ja not_active Expired - Fee Related
  • 1986-06-05 DE DE8686903683T patent/DE3666148D1/de not_active Expired
  • 1986-06-05 US US07/016,383 patent/US4767061A/en not_active Expired - Lifetime
  • 1986-06-05 WO PCT/SE1986/000263 patent/WO1986007289A1/en active IP Right Grant

Patent Citations (4)

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