CA1068857A - Process and apparatus for producing granules by solidification of drops of a liquid phase product - Google Patents
Process and apparatus for producing granules by solidification of drops of a liquid phase productInfo
- Publication number
- CA1068857A CA1068857A CA259,222A CA259222A CA1068857A CA 1068857 A CA1068857 A CA 1068857A CA 259222 A CA259222 A CA 259222A CA 1068857 A CA1068857 A CA 1068857A
- Authority
- CA
- Canada
- Prior art keywords
- bed
- fluidised
- drops
- zone
- process according
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J2/00—Processes or devices for granulating materials, e.g. fertilisers in general; Rendering particulate materials free flowing in general, e.g. making them hydrophobic
- B01J2/16—Processes or devices for granulating materials, e.g. fertilisers in general; Rendering particulate materials free flowing in general, e.g. making them hydrophobic by suspending the powder material in a gas, e.g. in fluidised beds or as a falling curtain
Abstract
ABSTRACT OF THE DISCLOSURE
A process and an apparatus for granulating a product in form of drops wherein the drops of the product to be granu-lated are introduced into a fluidised bed of pulverulent solid material kept at a suitable temperature in a container, wherein circulation flow is imparted to the bed and the circulation currents are used to separate the obtained granules from the pulverulent solid material. The invention can be used to granulate various molten products, for example pitch, bitumen, thermoplastic resins and glass, and can also be used to granulate products in concentrated solutions.
A process and an apparatus for granulating a product in form of drops wherein the drops of the product to be granu-lated are introduced into a fluidised bed of pulverulent solid material kept at a suitable temperature in a container, wherein circulation flow is imparted to the bed and the circulation currents are used to separate the obtained granules from the pulverulent solid material. The invention can be used to granulate various molten products, for example pitch, bitumen, thermoplastic resins and glass, and can also be used to granulate products in concentrated solutions.
Description
~O~t~8S7 The present invention relates to a process for producing granules by solidification of drops of a liquid phase material and an apparatus therefor.
It is already known to granulate substances such as pitch, for example, by introducing them in drops into a current of water. The granules of product obtained by this process nevertheless entrain a little water, which is inconvenient for certain applications, so that a dry ng treatment is required.
It is also known to granulate substances in the liquid state by forming them into drops which are introduced into a container containing a fluidised bed. British Patent No.
1,356,443 describes a process of this kind. Nevertheless, in processes of this type difficulties sometimes arise with certain materials due to the sticking together of the granules when they , come into contact before being completely solidified; the discharge of the products from the granulator also gives rise to problems.
It is a main object of the invention to overcome these difficulties and obtain granules which are generally uniform in ; shape and size.
According to the present invention there is provided a ; process for producing granules by solidification of drops of a liquid-phase product, such as a molten product or a concentrated . ~
solution capable of solidifying by crystallization, comprising ~-introducing drops of the liquid to be granulated lnto a bed flui-dized with a fluidizing agent, the bed being formed of a powdered solid material maintained at an appropriate temperature and moved , by a circulatory flow, the circulatory flow in the powdered solid j material being obtained by placing said material in a chamber comprising a fluidized bed zone formed as a vertical column and a 30 non-fluidized zone formed as a vertical column, the chamber being subjected to vibrations.
.~ ' `
B ~ - 2 -10~ 7 The bed permits the solidification of the drops and, because of the circulation flow in the bed, enables the drops to be entrained immediately upon their arrival in the bed.
The circulation flow of the particulate material is preferably perpendicular to the direction of introduction of the drops. It may however have any other direction.
The circulation of the particulate material of the fluidised bed may be achieved by any means known per se. A
circulation flow can, for example, be achieved by feeding one end of the fluidised bed with particulate material and withdrawing from the bed an equivalent amount of particulate material at the other end. The speed of circulation must be sufficient to enable the drops to be separated from one another as soon as they arrive in the bed. However, experience ` shows that it is preferable for the rate of flow of the particulate material to be very great in comparison with that of the granulated product to obtain a sufficiently rapid ; entraining movement.
For this reason in a preferred embodiment of the ~invention the circulation flow of the solid particulate material is obtained by placing this material inside a container comprising a vertical columnar fluidised bed zone and a vertical columnar non-fluidised zone, the container " being subjected to vibrations. Inside the container, circulation currents are thus created in the non-fluidised zone, and these in turn give rise to circulation in the fluidised zone. `
The utilisation of vibrations makes it possible for the speed of circulation of the products in the fluidised zone to be regulated in a very flexible manner. In particular, it is possible to achieve rapid circulation permitting a high -; rate of flow of drops.
.. . . . . . . . . . . . . . .
10~;t3857 The circulation currents thus achie~ed in the non-fluidised zone can be used to separate from the particulate material of the bed the granules obtained by the process as described in United Kingdom Patent 1,474,422 in the name of the Applicants.
The temperature of the particulate material in the fluidised zone is kept sufficiently low to effect sufficiently rapid solidification of the drops to prevent the particulate material from sticking to the surface of the drops.
The heat released on the solidification of the molten products and their subsequent cooling has to be dissipated.
This can be achieved by regulating the temperature of the gas used to effect the fluidisation of the particulate material, but sufficient cooling of this gas to dissipate all the calories given up by the molten product, although technically - possible, cannot be achieved economically. It is to be noted that a limit is set to the air flow since it cannot exceed a certain value, for example 0.1 to 1 meter per second for solid particulate material.
The dissipation of the heat given up by the molten product can be considerably accelerated by providing heat exchange means in the bed. The heat exchange means may be ,~ a cooler in which a cooling fluid circulates. For example a water circulation type cooler may be located in the fluidised ~-~
layer above the grid through which the fluidising agent flows.
It is also possible to utilise the heat absorption capacity of certain changes of state, for example vaporisation. -A vaporisable liquid may be injected into the fluidising agent.
~: , ., :
' ~- 4 -' ~0~857 In the case of the vaporisation of water, the water is atomised into the fluidisation air and the evaporation of the microdrops in the fluidised layer will cool the latter.
Further, a vaporisable liquid may be injected into the fluidised bed. For example water may be injected directly into the fluidised layer itself. Another way to supply heat to or extract heat from the fluidised bed, is to discharge part (for example 10~) of the solid particulate material from the bed, then to heat or cool the part discharged and to reintroduce it after heating or cooling into the fluidised bed.
It has been found, surprisingly, that when the cooling achieved in this manner was sufficiently vigorous, spherical granules were obtained which contained practically no particulate material sticking to their surfaces. Conversely, the speed of ; cooling can be regulated so that a certain amount of the partic-ulate material adheres to the surface of the granules if this material has particular properties, such as an anti-caking action, or a filler action. It should be noted that the particulate material may be the same product as the actual product which is to be granulated, providing such material is ground to the desired ` fineness to permit fluidisation. In this case the entrainment of the particular material adhering to the surface of the granules is not troublesome.
The product to be granulated may be introduced into the ~-bed in the molten state. The process of the invention can thus be applied to the granulation of various molten products, for example pitch, bitumen, thermoplastic resins, or glass. The ~ :
process can also be used to granulate concentrated solutions : .
,`~
-` 10~ 57 introduced into the bed, by solidifying by crystallisation, for example solutions of urea or ammonium nitrate.
The invention also comprehends an apparatus for granul-ating a material in the form of drops, comprising a fluidisation container having closed side walls and a bottom and containing a bed of pulverulent solid material used as a processing phase, the bottom of said container comprising a grid and means for feeding a fluidisation agent upwards through the grid, the surface of said bottom being constituted party of the grid and partly of at least one continuous masking element so that only a vertical columnar zone above the grid is fluidised by the fluidisation agent while above the remaining portion of the grid are one or more non-fluidised vertical zones, i.e., one or more zones not subjected to the action of the fluidisation agent, said apparatus further comprising vibrating means for vibrating said container by means of vibrations applied in a direction which is inclined from the horizonta~ heat exchange means provided ` in the bed, and means for introducing drops into the vertical ~
zone subjected to the action of the fluidisation agent. ~-In a preferred embodiment the apparatus may comprise - -separating and discharging means consisting of at least an inclined discharging screen located at least partly in one of the said non-fluidised zones to discharge at an external over-flow point. -It is an important advantage of the invention that large quantities of granules can be processed by allowing recycling ~-of very small amounts of solid particulate material forming the - 6 ~
B
385~
fluidised bed while the speed of travel of the particulate material is sufficiently high to move the granules away from the place where the liquid phase product is dropped into the bed. Thus the formation of clusters is avoided, because the granules being formed has insufficient time to gather at their dropping place and they are rapidly entrained towards the separating means.
As is known, vibrations are not transmitted through a fluidised bed; thus the granules are subjected to normal conditions of fluidisation. The vibrations however are transmitted to the non-fluidised portion of the bed of pulverulent product and tend to move it in the direction of application of the vibrations.
High efficiency is obtained when the direction of the vibration is substantially coincident with a direction corresponding to the non-fluidised portions of the bed of pulverulent product. Under the effect of the vibrations in such a direction, it is observed ; that the particulate material, with the granules it contains, moves towards one end of the non-fluidised zone when there is a `` straight non-fluidised zone.
At this end the particulate material gathers and by reason of the difference of level spills into the fluidised portion that flows like a liquid towards the other end of the device where it returns to the non-fluidised zone. In this way a rapid natural current of particulate material is established in the apparatus. Because of the vibrations, the particulate -material is directed towards the means for screening and dis-charging by vibrations.
~ ' 385'7 It is easy to control the rate of circulation of the products by adjusting the width of the non-fluidised zones, or the frequency and amplitude of the vibra~ions, or by inserting flow regulating flaps in the non-fluidised zone above the masking element.
The invention also comprehends products in granular form produced by the process of the invention.
In order that the invention may be more clearly understood some embodiments thereof will now be described, by way of example, with reference to the accompanying drawings, in which:-Figure 1 is a top view of an apparatus for carryingout the process of the invention, shown diagrammatically, Figure 2 is a diagrammatical section on the line AA' of the apparatus shown in Figure 1, and ~ -Figures 3 and 4 supplement Figures 1 and 2 and in particular show how a water circulation cooler can be fitted to the apparatus.
Referring to Figures 1 and 2, the apparatus comprises a rectangular vessel 1, in which a grid 2 supports a fluidised bed of a solid particulate material and distributes the fluid-ising agent, such as a fluidising gas. At the base of the vessel there is a pipe 3 for supply of the fluidising gas.
Around the periphery of the grid 2 an unperforated metal plate 4 and 4' enables a peripheral non-fluidised zone 5 to be formed all around the fluidised bed. Partitions 6 partly separate this -zone from the fluidised aone. Flaps 15 are also provided to regulate the flow of the solid particulate material in the non-fluidised zone.
The apparatus also contains a vibration genèrator 7 connected to the vessel by lateral arms 8. The direction of the vibrations is inclined and in vertical plan parallel to the direction of the major dimension of the longitudinal plate 4'.
Screens 9 placed in the non-fluidised zone enable the granules formed to be discharged to the outside. A drop generator 10, shown disgrammatically in Figure 3, enables drops to be intro-10 duced into the fluidised 20ne and at the greatest distance fromthe vibrator. Through the action of the vibrations, circulation currents, represented by arrows 11 in Figure 1, are formed in the vessel, and through the action of these currents the granules formed are discharged onto the screens 9. The particulate material of the fluidised bed passes through the screens and ~ remains in the vessel, while the granules move along the top of - the screens to a suitable discharge point for discharge from the system. -`~
Figures 3 and 4 show a water circulation heat exchanger `
for cooling the fluidised bed. This cooler consists of a nest of tubes 12 placed above the grid 2. At their end the tubes `
are connected in common to a water inlet pipe 13 and to a water outlet pipe 14.
The apparatus shown in the accompanying drawings has been used for granulating an electrode pitch having a Kramer and ; Sarnow melting point KS 70-80C.
I
The molten pitch is kept at 170C in a vessel the bottom of which is pierced with round holes of 2 mm diameter. When it ; 30 flows through these apertures the pitch is divided into .
, _ 9 _ .,~
.
. -drops, which fall into a fluidised bed of silica sand whose granulometry is under 0.2 mm. The layer of sand is fluidised by blowing air at 20C upwardly through the grid 2 and through the water circulation heat exchanger disposed inside the layer.
Under these operating conditions quasi-spherical balls or granules of pitch of a diameter 3 mm to 5 mm are obtained which have very little of the material of the bed adhering to their surface (less than 0.2~). If this small amount of silica could not be tolerated for the purposes for which the pitch is to be used, the silica of the fluidised bed could easily be replaced by a less troublesome material, such as alumina or coke dust.
The vessel containing the molten pitch may be sub-jected to vibrations. This means makes it possible to increase the flow of drops through each aperture or to lower the tem-peràture of the molten pitch, for example to use pitch at 155C
instead of 170C.
The process is carried out as in Example 1 but using, instead of pitch, a bitumen distillation fraction of KS 100 (Escorez resins - Registered Trade Mark).
, Granules similar to those of Example 1 containing practically no material of the fluidised bed are obtained.
ExAMæLE 3 :
Novolaks (phenol-formol resins) melted at 100C to achieve correct fluidity are granulated as in Example 1 in a fluidised bed of silica sand whose particles pass through a ; 0.2 mm screen, the bed being kept at a temperature of 20C.
Very hard granules, with low fragility, of a diameter of from ~ -
It is already known to granulate substances such as pitch, for example, by introducing them in drops into a current of water. The granules of product obtained by this process nevertheless entrain a little water, which is inconvenient for certain applications, so that a dry ng treatment is required.
It is also known to granulate substances in the liquid state by forming them into drops which are introduced into a container containing a fluidised bed. British Patent No.
1,356,443 describes a process of this kind. Nevertheless, in processes of this type difficulties sometimes arise with certain materials due to the sticking together of the granules when they , come into contact before being completely solidified; the discharge of the products from the granulator also gives rise to problems.
It is a main object of the invention to overcome these difficulties and obtain granules which are generally uniform in ; shape and size.
According to the present invention there is provided a ; process for producing granules by solidification of drops of a liquid-phase product, such as a molten product or a concentrated . ~
solution capable of solidifying by crystallization, comprising ~-introducing drops of the liquid to be granulated lnto a bed flui-dized with a fluidizing agent, the bed being formed of a powdered solid material maintained at an appropriate temperature and moved , by a circulatory flow, the circulatory flow in the powdered solid j material being obtained by placing said material in a chamber comprising a fluidized bed zone formed as a vertical column and a 30 non-fluidized zone formed as a vertical column, the chamber being subjected to vibrations.
.~ ' `
B ~ - 2 -10~ 7 The bed permits the solidification of the drops and, because of the circulation flow in the bed, enables the drops to be entrained immediately upon their arrival in the bed.
The circulation flow of the particulate material is preferably perpendicular to the direction of introduction of the drops. It may however have any other direction.
The circulation of the particulate material of the fluidised bed may be achieved by any means known per se. A
circulation flow can, for example, be achieved by feeding one end of the fluidised bed with particulate material and withdrawing from the bed an equivalent amount of particulate material at the other end. The speed of circulation must be sufficient to enable the drops to be separated from one another as soon as they arrive in the bed. However, experience ` shows that it is preferable for the rate of flow of the particulate material to be very great in comparison with that of the granulated product to obtain a sufficiently rapid ; entraining movement.
For this reason in a preferred embodiment of the ~invention the circulation flow of the solid particulate material is obtained by placing this material inside a container comprising a vertical columnar fluidised bed zone and a vertical columnar non-fluidised zone, the container " being subjected to vibrations. Inside the container, circulation currents are thus created in the non-fluidised zone, and these in turn give rise to circulation in the fluidised zone. `
The utilisation of vibrations makes it possible for the speed of circulation of the products in the fluidised zone to be regulated in a very flexible manner. In particular, it is possible to achieve rapid circulation permitting a high -; rate of flow of drops.
.. . . . . . . . . . . . . . .
10~;t3857 The circulation currents thus achie~ed in the non-fluidised zone can be used to separate from the particulate material of the bed the granules obtained by the process as described in United Kingdom Patent 1,474,422 in the name of the Applicants.
The temperature of the particulate material in the fluidised zone is kept sufficiently low to effect sufficiently rapid solidification of the drops to prevent the particulate material from sticking to the surface of the drops.
The heat released on the solidification of the molten products and their subsequent cooling has to be dissipated.
This can be achieved by regulating the temperature of the gas used to effect the fluidisation of the particulate material, but sufficient cooling of this gas to dissipate all the calories given up by the molten product, although technically - possible, cannot be achieved economically. It is to be noted that a limit is set to the air flow since it cannot exceed a certain value, for example 0.1 to 1 meter per second for solid particulate material.
The dissipation of the heat given up by the molten product can be considerably accelerated by providing heat exchange means in the bed. The heat exchange means may be ,~ a cooler in which a cooling fluid circulates. For example a water circulation type cooler may be located in the fluidised ~-~
layer above the grid through which the fluidising agent flows.
It is also possible to utilise the heat absorption capacity of certain changes of state, for example vaporisation. -A vaporisable liquid may be injected into the fluidising agent.
~: , ., :
' ~- 4 -' ~0~857 In the case of the vaporisation of water, the water is atomised into the fluidisation air and the evaporation of the microdrops in the fluidised layer will cool the latter.
Further, a vaporisable liquid may be injected into the fluidised bed. For example water may be injected directly into the fluidised layer itself. Another way to supply heat to or extract heat from the fluidised bed, is to discharge part (for example 10~) of the solid particulate material from the bed, then to heat or cool the part discharged and to reintroduce it after heating or cooling into the fluidised bed.
It has been found, surprisingly, that when the cooling achieved in this manner was sufficiently vigorous, spherical granules were obtained which contained practically no particulate material sticking to their surfaces. Conversely, the speed of ; cooling can be regulated so that a certain amount of the partic-ulate material adheres to the surface of the granules if this material has particular properties, such as an anti-caking action, or a filler action. It should be noted that the particulate material may be the same product as the actual product which is to be granulated, providing such material is ground to the desired ` fineness to permit fluidisation. In this case the entrainment of the particular material adhering to the surface of the granules is not troublesome.
The product to be granulated may be introduced into the ~-bed in the molten state. The process of the invention can thus be applied to the granulation of various molten products, for example pitch, bitumen, thermoplastic resins, or glass. The ~ :
process can also be used to granulate concentrated solutions : .
,`~
-` 10~ 57 introduced into the bed, by solidifying by crystallisation, for example solutions of urea or ammonium nitrate.
The invention also comprehends an apparatus for granul-ating a material in the form of drops, comprising a fluidisation container having closed side walls and a bottom and containing a bed of pulverulent solid material used as a processing phase, the bottom of said container comprising a grid and means for feeding a fluidisation agent upwards through the grid, the surface of said bottom being constituted party of the grid and partly of at least one continuous masking element so that only a vertical columnar zone above the grid is fluidised by the fluidisation agent while above the remaining portion of the grid are one or more non-fluidised vertical zones, i.e., one or more zones not subjected to the action of the fluidisation agent, said apparatus further comprising vibrating means for vibrating said container by means of vibrations applied in a direction which is inclined from the horizonta~ heat exchange means provided ` in the bed, and means for introducing drops into the vertical ~
zone subjected to the action of the fluidisation agent. ~-In a preferred embodiment the apparatus may comprise - -separating and discharging means consisting of at least an inclined discharging screen located at least partly in one of the said non-fluidised zones to discharge at an external over-flow point. -It is an important advantage of the invention that large quantities of granules can be processed by allowing recycling ~-of very small amounts of solid particulate material forming the - 6 ~
B
385~
fluidised bed while the speed of travel of the particulate material is sufficiently high to move the granules away from the place where the liquid phase product is dropped into the bed. Thus the formation of clusters is avoided, because the granules being formed has insufficient time to gather at their dropping place and they are rapidly entrained towards the separating means.
As is known, vibrations are not transmitted through a fluidised bed; thus the granules are subjected to normal conditions of fluidisation. The vibrations however are transmitted to the non-fluidised portion of the bed of pulverulent product and tend to move it in the direction of application of the vibrations.
High efficiency is obtained when the direction of the vibration is substantially coincident with a direction corresponding to the non-fluidised portions of the bed of pulverulent product. Under the effect of the vibrations in such a direction, it is observed ; that the particulate material, with the granules it contains, moves towards one end of the non-fluidised zone when there is a `` straight non-fluidised zone.
At this end the particulate material gathers and by reason of the difference of level spills into the fluidised portion that flows like a liquid towards the other end of the device where it returns to the non-fluidised zone. In this way a rapid natural current of particulate material is established in the apparatus. Because of the vibrations, the particulate -material is directed towards the means for screening and dis-charging by vibrations.
~ ' 385'7 It is easy to control the rate of circulation of the products by adjusting the width of the non-fluidised zones, or the frequency and amplitude of the vibra~ions, or by inserting flow regulating flaps in the non-fluidised zone above the masking element.
The invention also comprehends products in granular form produced by the process of the invention.
In order that the invention may be more clearly understood some embodiments thereof will now be described, by way of example, with reference to the accompanying drawings, in which:-Figure 1 is a top view of an apparatus for carryingout the process of the invention, shown diagrammatically, Figure 2 is a diagrammatical section on the line AA' of the apparatus shown in Figure 1, and ~ -Figures 3 and 4 supplement Figures 1 and 2 and in particular show how a water circulation cooler can be fitted to the apparatus.
Referring to Figures 1 and 2, the apparatus comprises a rectangular vessel 1, in which a grid 2 supports a fluidised bed of a solid particulate material and distributes the fluid-ising agent, such as a fluidising gas. At the base of the vessel there is a pipe 3 for supply of the fluidising gas.
Around the periphery of the grid 2 an unperforated metal plate 4 and 4' enables a peripheral non-fluidised zone 5 to be formed all around the fluidised bed. Partitions 6 partly separate this -zone from the fluidised aone. Flaps 15 are also provided to regulate the flow of the solid particulate material in the non-fluidised zone.
The apparatus also contains a vibration genèrator 7 connected to the vessel by lateral arms 8. The direction of the vibrations is inclined and in vertical plan parallel to the direction of the major dimension of the longitudinal plate 4'.
Screens 9 placed in the non-fluidised zone enable the granules formed to be discharged to the outside. A drop generator 10, shown disgrammatically in Figure 3, enables drops to be intro-10 duced into the fluidised 20ne and at the greatest distance fromthe vibrator. Through the action of the vibrations, circulation currents, represented by arrows 11 in Figure 1, are formed in the vessel, and through the action of these currents the granules formed are discharged onto the screens 9. The particulate material of the fluidised bed passes through the screens and ~ remains in the vessel, while the granules move along the top of - the screens to a suitable discharge point for discharge from the system. -`~
Figures 3 and 4 show a water circulation heat exchanger `
for cooling the fluidised bed. This cooler consists of a nest of tubes 12 placed above the grid 2. At their end the tubes `
are connected in common to a water inlet pipe 13 and to a water outlet pipe 14.
The apparatus shown in the accompanying drawings has been used for granulating an electrode pitch having a Kramer and ; Sarnow melting point KS 70-80C.
I
The molten pitch is kept at 170C in a vessel the bottom of which is pierced with round holes of 2 mm diameter. When it ; 30 flows through these apertures the pitch is divided into .
, _ 9 _ .,~
.
. -drops, which fall into a fluidised bed of silica sand whose granulometry is under 0.2 mm. The layer of sand is fluidised by blowing air at 20C upwardly through the grid 2 and through the water circulation heat exchanger disposed inside the layer.
Under these operating conditions quasi-spherical balls or granules of pitch of a diameter 3 mm to 5 mm are obtained which have very little of the material of the bed adhering to their surface (less than 0.2~). If this small amount of silica could not be tolerated for the purposes for which the pitch is to be used, the silica of the fluidised bed could easily be replaced by a less troublesome material, such as alumina or coke dust.
The vessel containing the molten pitch may be sub-jected to vibrations. This means makes it possible to increase the flow of drops through each aperture or to lower the tem-peràture of the molten pitch, for example to use pitch at 155C
instead of 170C.
The process is carried out as in Example 1 but using, instead of pitch, a bitumen distillation fraction of KS 100 (Escorez resins - Registered Trade Mark).
, Granules similar to those of Example 1 containing practically no material of the fluidised bed are obtained.
ExAMæLE 3 :
Novolaks (phenol-formol resins) melted at 100C to achieve correct fluidity are granulated as in Example 1 in a fluidised bed of silica sand whose particles pass through a ; 0.2 mm screen, the bed being kept at a temperature of 20C.
Very hard granules, with low fragility, of a diameter of from ~ -
2 mm to 5 mm and entraining only very little sand, are obtained.
-- 10 -- .:-.
,,
-- 10 -- .:-.
,,
Claims (12)
1. A process for producing granules by solidification of drops of a liquid-phase product, such as a molten product or a concen-trated solution capable of solidifying by crystallization, com-prising introducing drops of the liquid to be granulated into a bed fluidized with a fluidizing agent, the bed being formed of a powdered solid material maintained at an appropriate temperature and moved by a circulatory flow, the circulatory flow in the powdered solid material being obtained by placing said material in a chamber comprising a fluidized bed zone formed as a verti-cal column and a non-fluidized zone formed as a vertical column, the chamber being subjected to vibrations.
2. A process according to claim 1, in which circulatory flows in the non-fluidized zone are used to separate, in that zone, the formed granules from the said powdered solid material.
3. A process according to either of claims 1 or 2, in which a heat exchange means is disposed in the bed.
4. A process according to either of claims 1 or 2, in which a vaporizable liquid is injected into the fluidizing agent before it is introduced into the bed.
5. A process according to either of claims 1 or 2, in which a vaporizable liquid is injected into the fluidized bed.
6. A process according to either of claims 1 or 2, in which water is injected into the fluidizing agent before it is intro-duced into the bed, and such water vaporizes within the bed, thereby cooling the bed.
7. A process according to either of claims 1 or 2, in which water is injected into the fluidized bed and such water vaporizes within the bed, thereby cooling the bed.
8. A process according to any one of Claims 1 or 2, wherein the product to be granulated is introduced into the bed in the molten state.
9. A process according to any one of Claims 1 or 2, wherein the product to be granulated is introduced into the bed in the state of a concentrated solution capable of solidifying by crys-tallisation.
10. An apparatus for granulating a material in the form of drops, comprising a fluidisation container having closed side walls and a bottom containing a bed of pulverulent solid material used as a processing phase, the bottom of said container comprising a grid and means for feeding a fluidisation agent upwards through the grid, the surface of said bottom being constituted partly of the grid and partly of at least one continuous masking element so that only a vertical columnar zone above the grid is fluidised by the fluidisation agent while above the remaining portion of the grid are one or more non-fluidised vertical zones which form one or more zones not subjected to the action of the fluidisation agent, said apparatus further comprising vibrating means for vi-brating said container by means of vibrations applied in a direction which is inclined to the horizontal, heat exchange means provided in the bed, and means for introducing drops into the vertical zone subjected to the action of the fluidisation agent.
11. An apparatus according to Claim 10, including separating and discharging means consisting of at least an inclined vibrating discharging screen located at least partly in one of the said non-fluidised zones to discharge at an external overflow point.
12. An apparatus according to Claim 10, comprising flow regulating flaps in the non-fluidised zone above the masking element.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB34285/75A GB1536849A (en) | 1975-08-18 | 1975-08-18 | Process for producing granules by solidification of a product in the liquid phase |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1068857A true CA1068857A (en) | 1980-01-01 |
Family
ID=10363724
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA259,222A Expired CA1068857A (en) | 1975-08-18 | 1976-08-17 | Process and apparatus for producing granules by solidification of drops of a liquid phase product |
Country Status (18)
| Country | Link |
|---|---|
| AU (1) | AU503925B2 (en) |
| BE (1) | BE845124A (en) |
| BR (1) | BR7605352A (en) |
| CA (1) | CA1068857A (en) |
| CH (1) | CH602177A5 (en) |
| DE (1) | DE2636806A1 (en) |
| DK (1) | DK142862B (en) |
| FI (1) | FI762315A (en) |
| FR (1) | FR2321321A1 (en) |
| GB (1) | GB1536849A (en) |
| IE (1) | IE44229B1 (en) |
| IN (1) | IN144982B (en) |
| IT (1) | IT1065786B (en) |
| LU (1) | LU75595A1 (en) |
| NL (1) | NL7609124A (en) |
| NO (1) | NO762797L (en) |
| SE (1) | SE7609118L (en) |
| ZA (1) | ZA764904B (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2947196A1 (en) * | 1979-11-23 | 1981-05-27 | Escher Wyss Gmbh, 7980 Ravensburg | Fluidised bed cooler for hot solid particles - has by=pass to compensate air or product temperature variations |
| JPS6012895B2 (en) * | 1979-11-28 | 1985-04-04 | 三井東圧化学株式会社 | Granulation equipment |
| AU567587B2 (en) * | 1983-10-17 | 1987-11-26 | Austgen-Biojet Holdings Pty Ltd | Fluidised bed waste water treatment reactor |
| DE3518512A1 (en) * | 1985-05-23 | 1986-11-27 | Inter Power Technologie GmbH, 6600 Saarbrücken | METHOD FOR GENERATING ELECTRICITY AND HEAT BY MEANS OF A PRINTED FLUID BED BURNER |
| DE10230533A1 (en) * | 2002-07-05 | 2004-01-22 | Inprotec Ag | Crystallization of a wide range of difficult-to-crystallizable materials involves converting a melt to a finely-divided form and contacting it with a crystalline powder |
-
1975
- 1975-08-18 GB GB34285/75A patent/GB1536849A/en not_active Expired
-
1976
- 1976-08-12 NO NO762797A patent/NO762797L/no unknown
- 1976-08-12 BE BE169757A patent/BE845124A/en not_active IP Right Cessation
- 1976-08-12 FI FI762315A patent/FI762315A/fi not_active Application Discontinuation
- 1976-08-12 FR FR7624602A patent/FR2321321A1/en active Granted
- 1976-08-13 AU AU16837/76A patent/AU503925B2/en not_active Expired
- 1976-08-13 IN IN1476/CAL/76A patent/IN144982B/en unknown
- 1976-08-13 LU LU75595A patent/LU75595A1/xx unknown
- 1976-08-13 IT IT26284/76A patent/IT1065786B/en active
- 1976-08-16 IE IE1812/76A patent/IE44229B1/en unknown
- 1976-08-16 BR BR7605352A patent/BR7605352A/en unknown
- 1976-08-16 ZA ZA764904A patent/ZA764904B/en unknown
- 1976-08-16 DK DK369576AA patent/DK142862B/en unknown
- 1976-08-16 SE SE7609118A patent/SE7609118L/en unknown
- 1976-08-16 DE DE19762636806 patent/DE2636806A1/en not_active Withdrawn
- 1976-08-17 CH CH1045576A patent/CH602177A5/xx not_active IP Right Cessation
- 1976-08-17 CA CA259,222A patent/CA1068857A/en not_active Expired
- 1976-08-17 NL NL7609124A patent/NL7609124A/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| AU503925B2 (en) | 1979-09-27 |
| IT1065786B (en) | 1985-03-04 |
| FR2321321B1 (en) | 1981-02-20 |
| DK142862C (en) | 1981-09-28 |
| BE845124A (en) | 1977-02-14 |
| IE44229B1 (en) | 1981-09-23 |
| LU75595A1 (en) | 1977-09-13 |
| DE2636806A1 (en) | 1977-03-03 |
| DK142862B (en) | 1981-02-16 |
| GB1536849A (en) | 1978-12-20 |
| BR7605352A (en) | 1977-08-16 |
| AU1683776A (en) | 1978-02-16 |
| NL7609124A (en) | 1977-02-22 |
| SE7609118L (en) | 1977-02-19 |
| NO762797L (en) | 1977-02-21 |
| IE44229L (en) | 1977-02-18 |
| FI762315A (en) | 1977-02-19 |
| ZA764904B (en) | 1977-07-27 |
| CH602177A5 (en) | 1978-07-31 |
| DK369576A (en) | 1977-02-19 |
| FR2321321A1 (en) | 1977-03-18 |
| IN144982B (en) | 1978-08-05 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |