Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F26—DRYING
  • F26B—DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM
  • F26B21/00—Arrangements for supplying or controlling air or other gases for drying solid materials or objects
  • F26B21/30—Controlling, e.g. regulating, parameters of gas supply

Definitions

• This invention relates to method and means for drying, and more precisely a method and means of the class which operates with combustion of gas and which are adapted for removal of moisture from the surface of objects.
• Previously known drying apparatuses which operate with com ⁇ bustion of gas may, simply stated, be said to constitute gas burners for heating of the surface, which should be dried, to such a temperature that water or moisture on the surface is removed essentially by vaporization .and evaporation due to the rise of the surface temperature.
• gas burners for heating of the surface, which should be dried, to such a temperature that water or moisture on the surface is removed essentially by vaporization .and evaporation due to the rise of the surface temperature.
• a comparatively large amount of heat.energy is required to heat the surface to such an extent that evaporation takes place.
• gas such as bottled gas
• there are also generated large quatities of water vapor viz. of the order of about 2 cubic meters of water vapor per kilogram of gas. In one way or another also that water vapor must be removed to reach an effective drying. Therefore, the efficiency of the known drying apparatuses is normally very low.
• a method of drying a surface of an object according to the present invention comprises controlling the relative humidity of a gaseous pressurized drying medium to be essentially lower than that of the natural air layer immediately adjacent to the surface to be dried, blowing said pressurized drying medium onto the surface to be dried at a velocity of between 5 and 80 m/sec, preferably
• SUBSTITUTE SHEET a velocity of between 25 and 60 m/sec, as said drying medium exits from a blowing means, and controlling the temperature of said pressurized drying medium, as it exits from said blowing means, to be in the range of 5 to 150°C, preferably about 70 to 95°C.
• the controlling of the relative humidity of the pressurized drying medium according to the invention is effected by com ⁇ pressing ordinary ambient air and removing liquified water therefrom down to a relative humidity of the compressed air of about 1 to 10 percent, preferably down to a range of about
• the compressed air or the air to be compressed, from a space different from and physically separated from the space where drying is to take place.
• a drying apparatus which comprises, in combination, means for controlling the relative humidity of a gaseous pressurized drying medium to be essentially lower than that of the natural air layer immediately adjacent to the surface to be dried, means for flowing said pressurized drying medium onto the surface to be dried, means for controlling the velocity of the drying medium as it exits from the blowing means to be in the range of between 5 and 80 m/sec, preferably a velocity between 25 and 60 m/sec, and means for controlling the temperature of said pressurized drying medium, as it exits from said blowing means, to be in the range of 5 to 150°C, preferably about 70 to 95°C.
• means for controlling the temperature of said pressurized drying medium comprises a gas burner head, disposed to permit the flame thereof surround the end portion of the drying medium tube to heat said end portion and the pressurized drying medium therein immediately before its exit from said end portion.
• the gas burner head is of the cyclone type or whirler type.
• FIG. 1 shows a side view of one embodiment of a drying apparatus according to the invention
• FIG. 2 shows an axial longitudinal cross section through the foremost end of the drying apparatus in FIG. 1;
• FIG. 3 shows a cross sectional view as seen in the plane III-III in FIG. 2;
• FIG. 4 illustrates a detail of the drying apparatus as shown in FIG. 1.
• the drying apparatus in FIG. 1 comprises a gas tube, generally denoted 10, and a drying medium tube, generally denoted 11.
• the two tubes 10 and 11 are held clamped together in a parallel relationship by means of two clamps 12, 12, and a further, middle clamp 13, to which middle clamp 13 there is secured a transverse handle 14.
• This middle clamp 13 is longi ⁇ tudinally movable along the two tubes 11, 11.
• valve means for control of the gas flow
• burner head 16 which in the instant case is of the cyclone- or whirlertype.
• a valve means for control of the flow of drying medium, usually compressed air.
• the rear end of the drying medium tube 17 is bent downwardly from the gas tube 10 to ensure accessability to the gas valve means 15 and the hand grip H provided for holding the apparatus. Further, this bending downwardly of the rear end of the drying
• SUBSTITUTE SHEET medium tube 11 ensures that a hose (not shown) for admission of compressed air to be used as drying medium, will be held in a suitable angle with respect to the apparatus.
• the drying medium tube 11 has its foremost end (the left hand end as shown in FIGS. 1 and 2) bent in such a manner that the tube in question has a considerable portion 18 disposed within the flame (not shown) that emerges from the gas burner head 16, as will be discussed in more details below.
• a gas nozzle 19 Between the handle H with its valve means 15 there is disposed a gas nozzle 19, FIGS. 1 and 4, having an orifice of a suitable size, such as a diameter of about 1.0 mm.
• the mouth of the gas orifice is disposed centrally of the nozzle 19, and the nozzle is adapted to eject the gas into the rear end of the gas tube 10.
• the valve means 15. comprises one controllable valve 15A for control of the magnitude of a pilot flame which is always present within the burner head 16 when the apparatus is in use. Further, the valve means 15 comprises a controllable main valve 15B for control of the magnitude of a main flame within the burner head when the apparatus is effectively in operation.
• the "on/off" status of the apparatus is controlled by means of a spring biased lever L which controls an "on/off” gas valve which may form a portion of the valve 15B.
• the lever L may be locked in the "on”-position by means of a spring biased latch 21 which engages with the lever L in its “on”-position and locks the lever in that position until the lever L is actuated once again, at which moment the latch 21 automatically returns to its unlocking position.
• the cyclone-burner 16 com ⁇ prises an open ended cylindrical outer jacket 22 which is affixed to the foremost end of the gas tube 11. Near its inlet end, e.g. the right hand end in FIGS. 1 and 2, the
• SUBSTITUTE SHEET 23 has a plurality of throughgoing bores 24, in the instant case five such bores 24, which are disposed with a slight inclination with respect to the longtidinal central axis of the jacket 22.
• this bores 24 bring about a very intensive rotary or whirling motion of the gas/air mixture as it passes through the cyclone burner 16 and as it exits there ⁇ from in the shape of a whirling flame.
• this whirling flame surrounds the foremost end of the drying medium tube 18 completely, and strikes the surface of such foremost tube end in such a manner that it will be heated very effectively.
• the drying medium tube has, at the foremost end thereof, a nozzle 29 having an orifice of a diameter of about 3.0 mm, in the instant case.
• the foremost end of the complete apparatus i.e. the left hand end as shown in FIGS. 1 and 2, is provided with a protective outer shell 25, preferably made from stainless steel sheet.
• the shell 25 has a plurality of holes 26 to reduce the weight thereof, and also to permit dissipation of heat.
• the shell 25 is provided with two laterally projecting brackets 27,28 to support the apparatus when placed on a base, such as a floor.
• a compressor 30 to feed the drying medium tube 11 with compressed air, to be used as a drying medium in the instant case, viz. through a line 31.
• a gas bottle 32 from which bottled gas is fed to the apparatus through a line 33.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Drying Of Solid Materials (AREA)
• Application Of Or Painting With Fluid Materials (AREA)
• Cleaning Or Drying Semiconductors (AREA)
• Processing And Handling Of Plastics And Other Materials For Molding In General (AREA)

Applications Claiming Priority (3)

Publications (2)

Family

ID=22995141

Family Applications (1)

Country Status (5)

Family Cites Families (5)

• 1989
  • 1989-10-23 DE DE68925479T patent/DE68925479D1/de not_active Expired - Lifetime
  • 1989-10-23 EP EP89912016A patent/EP0401317B1/de not_active Expired - Lifetime
  • 1989-10-23 AU AU44898/89A patent/AU4489889A/en not_active Abandoned
  • 1989-10-23 AT AT89912016T patent/ATE133247T1/de not_active IP Right Cessation
  • 1989-10-23 WO PCT/SE1989/000581 patent/WO1990004747A1/en not_active Ceased

Non-Patent Citations (1)

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