Pelletizing method and apparatus

Claim 1

The method of maintaining within a predetermined range the temperature of a zone where solid particles falling through the air into a rotating bed of such particles are sprayed with a substance which adheres to the surface of the falling particles, comprising the steps of: A. removing some of the particles from said bed; B. wetting the removed particles with a liquid; and C. dropping the wetted particles into said zone, whereby evaporation of the liquid from said wetted particles as they pass through said zone lowers the temperature of said zone.

Claim 2

The method of maintaining within a predetermined range the temperature of a zone where solid particles falling through the air into a rotating bed of such particles are sprayed with a substance which adheres to the surface of the falling particles, comprising the steps of: A. removing some of the particles from said bed; B. wetting the removed particles with a liquid; and C. dropping the wetted particles into said zone, whereby evaporation of the liquid from said wetted particles as they pass through said zone lowers the temperature of said zone.

Claim 3

The method of maintaining within the range of about 160°-200° F. the temperature of a zone where solid sulfur particles falling through the air into a rotating bed of such particles are sprayed with molten sulfur which adheres to the surface of the falling particles, comprising the steps of: A. removing some of the particles from said bed; B. wetting the removed particles with a liquid; and C. dropping the wetted particles into said zone, whereby evaporation of the liquid from said wetted particles as they pass through said zone lowers the temperature of said zone.

Claim 4

The method of maintaining within the range of about 160°-200° F. the temperature of a zone where solid sulfur particles falling through the air into a rotating bed of such particles are sprayed with molten sulfur which adheres to the surface of the falling particles, comprising the steps of: A. removing some of the particles from said bed; B. wetting the removed particles with a liquid; and C. dropping the wetted particles into said zone, whereby evaporation of the liquid from said wetted particles as they pass through said zone lowers the temperature of said zone.

Claim 7

The method of maintaining within the range of about 160°-200° F. the temperature of a zone where solid sulfur particles falling through the air into a rotating bed of such particles are sprayed with molten sulfur which adheres to the surface of the falling particles, comprising the steps of: A. lifting some of the particles above said bed; B. wetting the lifted particles by spraying them with water; C. dropping the wetted particles to said bed; D. mixing the wetted particles with the other particles in said bed; E. elevating the mixed wetted and other particles above said zone; and F. dropping the mixture of wetted and other particles into said zone, whereby evaporation of the water from said wetted particles as they pass through said zone lowers the temperature of said zone.

Claim 8

The method of maintaining within the range of about 160°-200° F. the temperature of a zone where solid sulfur particles falling through the air into a rotating bed of such particles are sprayed with molten sulfur which adheres to the surface of the falling particles, comprising the steps of: A. lifting some of the particles above said bed; B. wetting the lifted particles by spraying them with water; C. dropping the wetted particles to said bed; D. mixing the wetted particles with the other particles in said bed; E. elevating the mixed wetted and other particles above said zone; and F. dropping the mixture of wetted and other particles into said zone, whereby evaporation of the water from said wetted particles as they pass through said zone lowers the temperature of said zone.

Claim 9

The method of producing solid pellets comprising the steps of: A. forming an elongated bed of solid particles; B. continuously elevating particles from said bed to a zone above said bed; C. dropping the elevated particles in two separated, distinct, generally continuous curtains of particles which fall into said bed at spaced locations; D. spraying a substance which adheres to the surface of the falling particles into one of said curtains of particles; E. humidifying the other curtain of particles; and F. removing from said bed pellets larger than a predetermined size.

Claim 10

The method of producing solid pellets comprising the steps of: A. forming an elongated bed of solid particles; B. continuously elevating particles from said bed to a zone above said bed; C. dropping the elevated particles in two separated, distinct, generally continuous curtains of particles which fall into said bed at spaced locations; D. spraying a substance which adheres to the surface of the falling particles into one of said curtains of particles; E. humidifying the other curtain of particles; and F. removing from said bed pellets larger than a predetermined size.

Claim 23

The method of producing solid generally spherical sulfur pellets comprising the steps of: A. forming an elongated bed of solid sulfur particles; B. inclining said elongated bed slightly with respect to the horizon from an entrance end to a discharge end; C. rotating said bed with respect to its axis, whereby solid particles in said bed move from said entrance end to said discharge end; D. lifting one elongated edge of said bed above the other elongated edge; E. continuously elevating particles from said bed to a zone above said bed; F. dropping the elevated particles in two separated, distinct, generally continuous curtains of particles which fall into said bed at spaced locations; G. dropping one of said curtains of particles into said bed between the center of said bed and the higher of said edges; H. dropping the other curtain of particles into said bed between the center of said bed and the lower of said edges; I. spraying molten sulfur into one of said curtains of particles; J. spraying said other curtain of particles with water above said bed; K. maintaining the temperature of said bed in the range of about 120°-180° F.; L. cooling said particles to a temperature in the range of about 120°-160° F.; and M. removing from said bed cooled pellets larger than about 2 to 20 m.m. in diameter.

Claim 24

The method of producing solid generally spherical sulfur pellets comprising the steps of: A. forming an elongated bed of solid sulfur particles; B. inclining said elongated bed slightly with respect to the horizon from an entrance end to a discharge end; C. rotating said bed with respect to its axis, whereby solid particles in said bed move from said entrance end to said discharge end; D. lifting one elongated edge of said bed above the other elongated edge; E. continuously elevating particles from said bed to a zone above said bed; F. dropping the elevated particles in two separated, distinct, generally continuous curtains of particles which fall into said bed at spaced locations; G. dropping one of said curtains of particles into said bed between the center of said bed and the higher of said edges; H. dropping the other curtain of particles into said bed between the center of said bed and the lower of said edges; I. spraying molten sulfur into one of said curtains of particles; J. spraying said other curtain of particles with water above said bed; K. maintaining the temperature of said bed in the range of about 120°-180° F.; L. cooling said particles to a temperature in the range of about 120°-160° F.; and M. removing from said bed cooled pellets larger than about 2 to 20 m.m. in diameter.

Claim 25

The method of producing sulfur seed particles capable of having their size increased until they are sulfur pellets larger than a predetermined size, comprising the steps of: A. forming an elongated bed of solid sulfur particles of various sizes, and maintaining the temperature of said bed in the range of about 120°-180° F.; B. rotating said bed; C. continuously elevating particles from said bed; D. dropping the elevated particles in a generally continuous curtain of particles which fall back into said bed; E. coating the falling particles by spraying molten sulfur into said curtain of falling particles; F. intermittantly raising the temperature of said bed by at least about 40° F. for brief periods, whereby sprayed sulfur coated on to the falling particles will remain at least partially plastic after said particles fall back into said bed; and G. continuing to rotate said bed during the periods when it is at a raised temperature, thereby abrading the partially plastic sulfur coating from the sprayed particles so as to form sulfur seed particles.

Claim 26

The method of producing sulfur seed particles capable of having their size increased until they are sulfur pellets larger than a predetermined size, comprising the steps of: A. forming an elongated bed of solid sulfur particles of various sizes, and maintaining the temperature of said bed in the range of about 120°-180° F.; B. rotating said bed; C. continuously elevating particles from said bed; D. dropping the elevated particles in a generally continuous curtain of particles which fall back into said bed; E. coating the falling particles by spraying molten sulfur into said curtain of falling particles; F. intermittantly raising the temperature of said bed by at least about 40° F. for brief periods, whereby sprayed sulfur coated on to the falling particles will remain at least partially plastic after said particles fall back into said bed; and G. continuing to rotate said bed during the periods when it is at a raised temperature, thereby abrading the partially plastic sulfur coating from the sprayed particles so as to form sulfur seed particles.

Claim 31

The method of producing sulfur seed particles capable of having their size increased until they are sulfur pellets larger than a predetermined size, comprising the steps of: A. forming an elongated bed of solid sulfur particles of various sizes, and maintaining the temperature of said bed in the range of about 120°-180° F.; B. rotating said bed; C. continuously elevating particles from said bed; D. dropping the elevated particles into two separated, distinct curtains of particles; E. coating the falling particles by spraying molten sulfur into one curtain of falling particles; F. spraying water into the other curtain of falling particles to maintain said bed in the temperature range of about 120°-180° F.; G. intermittantly raising the temperature of said bed by at least about 40° F. for about 2% of the time by ceasing to spray water into said other curtain for brief periods, whereby sulfur sprayed on to the falling particles will remain at least partially plastic after said particles fall back into said bed; and H. continuing to rotate said bed during the periods when it is at a raised temperature, thereby abrading the partially plastic sulfur coating from the sprayed particles so as to form sulfur seed particles having a diameter in the size range of about 0.1 to 1.0 m.m.

Claim 32

The method of producing sulfur seed particles capable of having their size increased until they are sulfur pellets larger than a predetermined size, comprising the steps of: A. forming an elongated bed of solid sulfur particles of various sizes, and maintaining the temperature of said bed in the range of about 120°-180° F.; B. rotating said bed; C. continuously elevating particles from said bed; D. dropping the elevated particles into two separated, distinct curtains of particles; E. coating the falling particles by spraying molten sulfur into one curtain of falling particles; F. spraying water into the other curtain of falling particles to maintain said bed in the temperature range of about 120°-180° F.; G. intermittantly raising the temperature of said bed by at least about 40° F. for about 2% of the time by ceasing to spray water into said other curtain for brief periods, whereby sulfur sprayed on to the falling particles will remain at least partially plastic after said particles fall back into said bed; and H. continuing to rotate said bed during the periods when it is at a raised temperature, thereby abrading the partially plastic sulfur coating from the sprayed particles so as to form sulfur seed particles having a diameter in the size range of about 0.1 to 1.0 m.m.

Claim 33

The method of reducing the amount of sulfur dust emitted during the manufacture of solid sulfur pellets, comprising the steps of: A. increasing the size of sulfur particles as they move from an entrance end to the discharge end of a bed of such particles; B. removing a mixture of particles of various sizes including dust from said discharge end of said bed; C. separating sulfur pellets that are larger than a predetermined size from the mixture of particles and dust removed from said bed; D. transporting back to the entrance end of said bed, those remaining particles and dust in said mixture that are smaller than said predetermined size; E. classifying said mixture as to particle size so that at least some dust is located below the larger particles; F. dropping the classified mixture on to the entrance end of said bed so as to define a curtain of falling particles in which the dust located below the larger particles is concentrated on one side of such curtain; and G. spraying molten sulfur on to said one side of said falling curtain before the particles reach said bed, whereby dust is coated with molten sulfur and is prevented from escaping.

Claim 34

The method of reducing the amount of sulfur dust emitted during the manufacture of solid sulfur pellets, comprising the steps of: A. increasing the size of sulfur particles as they move from an entrance end to the discharge end of a bed of such particles; B. removing a mixture of particles of various sizes including dust from said discharge end of said bed; C. separating sulfur pellets that are larger than a predetermined size from the mixture of particles and dust removed from said bed; D. transporting back to the entrance end of said bed, those remaining particles and dust in said mixture that are smaller than said predetermined size; E. classifying said mixture as to particle size so that at least some dust is located below the larger particles; F. dropping the classified mixture on to the entrance end of said bed so as to define a curtain of falling particles in which the dust located below the larger particles is concentrated on one side of such curtain; and G. spraying molten sulfur on to said one side of said falling curtain before the particles reach said bed, whereby dust is coated with molten sulfur and is prevented from escaping.

Claim 38

The method of reducing the amount of sulfur dust emitted during the manufacture of solid sulfur pellets, comprising the steps of: A. increasing the size of sulfur particles as they move from an entrance end to the discharge end of a bed of such particles; B. removing a mixture of particles of various sizes including dust from said discharge end of said bed; C. separating sulfur pellets that are larger than a predetermined size from the mixture of particles and dust removed from said bed; D. transporting back to the entrance end of said bed, those remaining particles and dust in said mixture that are similar than said predetermined size; E. classifying said mixture as to particle size by vibrating said particles and dust while they are being transported from said discharge end to said entrance end so that at least some dust is located below the larger particles. F. dropping the classified mixture on to the entrance end of said bed so as to define a curtain of falling particles about one inch thick in which the dust located below the larger particles is concentrated on one side of such curtain; and G. spraying molten sulfur on said one side of said falling curtain before the particles reach said bed, whereby dust is coated with molten sulfur and is prevented from escaping.

Claim 39

The method of reducing the amount of sulfur dust emitted during the manufacture of solid sulfur pellets, comprising the steps of: A. increasing the size of sulfur particles as they move from an entrance end to the discharge end of a bed of such particles; B. removing a mixture of particles of various sizes including dust from said discharge end of said bed; C. separating sulfur pellets that are larger than a predetermined size from the mixture of particles and dust removed from said bed; D. transporting back to the entrance end of said bed, those remaining particles and dust in said mixture that are similar than said predetermined size; E. classifying said mixture as to particle size by vibrating said particles and dust while they are being transported from said discharge end to said entrance end so that at least some dust is located below the larger particles. F. dropping the classified mixture on to the entrance end of said bed so as to define a curtain of falling particles about one inch thick in which the dust located below the larger particles is concentrated on one side of such curtain; and G. spraying molten sulfur on said one side of said falling curtain before the particles reach said bed, whereby dust is coated with molten sulfur and is prevented from escaping.

Claim 40

The method of producing solid sulfur pellets comprising the steps of: A. forming an elongated bed of solid sulfur particles; B. continuously elevating particles from said bed to a zone above said bed; C. dropping the elevated particles in two separated, distinct, generally continuous curtains of particles which fall into said bed at spaced locations; D. spraying molten sulfur into one of said curtains of particles; E. humidifying the other curtain of particles; F. removing a mixture of particles of various sizes including dust from one end of said bed; G. separating sulfur pellets that are larger than a predetermined size from the mixture of particles and dust removed from said bed; H. transporting back to the other end of said bed, those remaining particles and dust in said mixture that are smaller than said predetermined size; I. classifying said mixture as to particle size so that at least some dust is located below the larger particles; J. dropping the classified mixture on to said other end of said bed so as to define a third curtain of falling particles and dust in which the dust located below the larger particles is concentrated on one side of said third curtain; and K. spraying molten sulfur on said one side of said third curtain before the particles reach said bed, whereby dust is coated with molten sulfur and is prevented from escaping.

Claim 41

The method of producing solid sulfur pellets comprising the steps of: A. forming an elongated bed of solid sulfur particles; B. continuously elevating particles from said bed to a zone above said bed; C. dropping the elevated particles in two separated, distinct, generally continuous curtains of particles which fall into said bed at spaced locations; D. spraying molten sulfur into one of said curtains of particles; E. humidifying the other curtain of particles; F. removing a mixture of particles of various sizes including dust from one end of said bed; G. separating sulfur pellets that are larger than a predetermined size from the mixture of particles and dust removed from said bed; H. transporting back to the other end of said bed, those remaining particles and dust in said mixture that are smaller than said predetermined size; I. classifying said mixture as to particle size so that at least some dust is located below the larger particles; J. dropping the classified mixture on to said other end of said bed so as to define a third curtain of falling particles and dust in which the dust located below the larger particles is concentrated on one side of said third curtain; and K. spraying molten sulfur on said one side of said third curtain before the particles reach said bed, whereby dust is coated with molten sulfur and is prevented from escaping.