CA1133693A - Spray dryer - Google Patents
Spray dryerInfo
- Publication number
- CA1133693A CA1133693A CA310,158A CA310158A CA1133693A CA 1133693 A CA1133693 A CA 1133693A CA 310158 A CA310158 A CA 310158A CA 1133693 A CA1133693 A CA 1133693A
- Authority
- CA
- Canada
- Prior art keywords
- air
- nozzles
- drying
- plate
- larger
- 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
- B01D—SEPARATION
- B01D1/00—Evaporating
- B01D1/16—Evaporating by spraying
- B01D1/18—Evaporating by spraying to obtain dry solids
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F26—DRYING
- F26B—DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM
- F26B3/00—Drying solid materials or objects by processes involving the application of heat
- F26B3/02—Drying solid materials or objects by processes involving the application of heat by convection, i.e. heat being conveyed from a heat source to the materials or objects to be dried by a gas or vapour, e.g. air
- F26B3/10—Drying solid materials or objects by processes involving the application of heat by convection, i.e. heat being conveyed from a heat source to the materials or objects to be dried by a gas or vapour, e.g. air the gas or vapour carrying the materials or objects to be dried with it
- F26B3/12—Drying solid materials or objects by processes involving the application of heat by convection, i.e. heat being conveyed from a heat source to the materials or objects to be dried by a gas or vapour, e.g. air the gas or vapour carrying the materials or objects to be dried with it in the form of a spray, i.e. sprayed or dispersed emulsions or suspensions
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Life Sciences & Earth Sciences (AREA)
- Microbiology (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Drying Of Solid Materials (AREA)
- Vaporization, Distillation, Condensation, Sublimation, And Cold Traps (AREA)
- Freezing, Cooling And Drying Of Foods (AREA)
- Nozzles (AREA)
Abstract
Abstract of the Disclosure An improved spray dryer is disclosed for drying heat sensitive food products under sanitary conditions with a maximum product recovery for a minimal dryer size. The dryer has an air flow system for moving air through a drying chamber at generally atmospheric pressure with a controlled laminar air flow. The product being dried is sprayed into the drying chamber by an air distributor plate with a relatively rapid air flow through and immediately surrounding the product spray and with a surrounding air flow of lower velocity. The dried droplets or powder are removed by a powder collector including a drag system.
Description
~133693 The present invention relates to improved method and means for spray drying and, more particularly, to an improved method and means for drying products such as heat sensitive food prodwcts under sanitary conditions.
The improved spray drying system and in particular the improved and cooperating atomizing means and air flow control means permit effective and rapid drying at minimum temperature to eliminate undesirable product over-heating.
The spray dryer and method of the present invention are an improvement upon prior drying method and means, for example, upon the spray drying method and means as described in applicant's United States patent No. 3,648,753 dated March 14, 1972. A drying system is disclosed in that patent which includes means for con-trolling drying air flow and product atomizing. The present in-vention is concerned with improvements in such a drying method and apparatus.
According to one aspect of the present invention, there is provided an improved air distribution plate for positioning in a hot air dryer between an air supply manifold and a drying chamber for distributing air into said drying chamber into an initial flow pattern of generally parallel streams of differing velocity and thereafter of a single blended stream of uniform velocity across the stream the combination of: a flat plate member; a plurality of elongated first tubular nozzles mounted in spaced positions in said plate; a plurality of relatively shorter and smaller diameter second elongated tubular nozzles mounted throughout said plate with generally uniform spacing and surround-ing said first nozzles; said first and second nozzles having ~L336~3 their axes positioned perpendicularly to said flat plate; fluid atom:izers mounted beyond the air outlets of said first nozzles, and means at the air exit ends of said first and second nozzles for causing the air flowing from said second nozzles to flare.
This aspect of the invention also provides an improved hot air dryer comprising the combination of: a manifold; a dry-ing chamber; and the air distribution plate positioned between the manifold and the drying chamber for distributing air into the drying chamber.
According to another aspect of the present invention, there is provided an improved method of spray drying liquid pro-duct comprising the steps of: passing heated drying air from a manifold to a drying chamber; initially distributing the air during the said passage into a plurality of larger flowing streams of heated air surrounded by a greater number of smaller flowing streams of heated air of relatively smaller cross-section and lower velocity; spraying the liquid product into said larger flow-ing streams, and causing said larger and smaller flowing streams to flare slightly initially and to thereby blend together further down-stream to form a final stream of uniform velocity in cross-section.
Brief Description of the Drawing A preferred embodiment of the invention has been chosen for purposes of illustration and description and is shown in the accompanying drawings, forming a part of the specification, wherein:
Figure 1 is a flow diagram of the operation of the improved spray drying method and means.
The improved spray drying system and in particular the improved and cooperating atomizing means and air flow control means permit effective and rapid drying at minimum temperature to eliminate undesirable product over-heating.
The spray dryer and method of the present invention are an improvement upon prior drying method and means, for example, upon the spray drying method and means as described in applicant's United States patent No. 3,648,753 dated March 14, 1972. A drying system is disclosed in that patent which includes means for con-trolling drying air flow and product atomizing. The present in-vention is concerned with improvements in such a drying method and apparatus.
According to one aspect of the present invention, there is provided an improved air distribution plate for positioning in a hot air dryer between an air supply manifold and a drying chamber for distributing air into said drying chamber into an initial flow pattern of generally parallel streams of differing velocity and thereafter of a single blended stream of uniform velocity across the stream the combination of: a flat plate member; a plurality of elongated first tubular nozzles mounted in spaced positions in said plate; a plurality of relatively shorter and smaller diameter second elongated tubular nozzles mounted throughout said plate with generally uniform spacing and surround-ing said first nozzles; said first and second nozzles having ~L336~3 their axes positioned perpendicularly to said flat plate; fluid atom:izers mounted beyond the air outlets of said first nozzles, and means at the air exit ends of said first and second nozzles for causing the air flowing from said second nozzles to flare.
This aspect of the invention also provides an improved hot air dryer comprising the combination of: a manifold; a dry-ing chamber; and the air distribution plate positioned between the manifold and the drying chamber for distributing air into the drying chamber.
According to another aspect of the present invention, there is provided an improved method of spray drying liquid pro-duct comprising the steps of: passing heated drying air from a manifold to a drying chamber; initially distributing the air during the said passage into a plurality of larger flowing streams of heated air surrounded by a greater number of smaller flowing streams of heated air of relatively smaller cross-section and lower velocity; spraying the liquid product into said larger flow-ing streams, and causing said larger and smaller flowing streams to flare slightly initially and to thereby blend together further down-stream to form a final stream of uniform velocity in cross-section.
Brief Description of the Drawing A preferred embodiment of the invention has been chosen for purposes of illustration and description and is shown in the accompanying drawings, forming a part of the specification, wherein:
Figure 1 is a flow diagram of the operation of the improved spray drying method and means.
- 2~
' :.
1:~33693 Figure 2 is a front elevational view of a preferred embodiment of the spray drying means in accordance with the pre-sent invention.
Figure 3 is a top plan view of the spray dryer of Figure 2.
Figure 4 is a vertical sectional view of the air distri-bution plate taken along line 4-4 on Figure 2.
Figure 5 is a vertical sectional view of Figure 4 taken along line 5-5 on figure 4.
~ - 2a -~, .
:
~3~3 Figure 6 is an enlarged fragmentary perspective view of the air distribution plate.
Figure 7 is a vertical sectional view of an air distribution plate taken along line 7-7 on Figure 6.
Figure 8 is a perspective view illustrating the product removing drag means.
Figure 9 is a horizontal sectional view taken along line 9-9 on Figure 8.
The improved air dryer and its method of operation will first be described generally with particular reference to Figures 1~ 2 and 3.
While the spray dryer 1, as described below, is conventionally installed in a suitable plant, it is pre~erred that the air being used in the drying operation be supplied from and returned to the outdoor~. For this purpose, the spray dryer 1 has an elongated air inlet ~ for the drying air supply which extends outside of the dryer building 3. Similarly, an elongated air outlet 4 is connected by suitable exhaust piping to the exit end of the spray dryer 1. The dryer 1 includes a heater 5 to raise the ~emperature of the air from inlet 2, under suitable thermostatic control~ to the desired drying temperature~ Air is fed to and through the heater 5 by means of an inlet air blower 6 coupled by suitable ducting 7 to the air heater 5.
The air ;nlet 2 includes a filter housing 8 conta;n;ng a roughing filter and a high efficiency absolute filter of the type commercially used in air flow filtering operations which will remove as much as 99.97% of all contaminants from the incoming air.
The air heater 5 may use heated coils 9 (Figure 3~ or it may employ direct or indirect heating furnace 5 employing suitable fuels such . ~ .
~3;~6~3 as oil or gas.
The heated air is fed downwardly to an air flow manifold 13 which communicates through an air distribution plate 10 to the drying chamber 11 of the dr~er 1. A n~mber of atomizing nozzles 12 are mounted on the air distribution plate 10 which are coupled through an adjustable fluid feed system 14 to a suitable source 23 of the liquid being dried. The construction and operation of the air distribution plate 10 and the related atomizing nozzles 12 will be described in greater detail below.
The drying chamber 11 t~rminates in a discharge end 15 which completes the removal of the dried or powdered product from the air flow permitting the separated air to pass upwardly to the air outlet 4. The dried product drops to the floor of the drying chamber 11 and is moved in the direction of air flow by a drag system 16 to the bottom of the discharge chamber ~5. A horizontal auger 17 carries the dried product to a removal auger 18 which feeds the dried powder to a vibrating sifter 19.
A final removal of any remaining dried product in the air stream is done at an autlet filter 200 h preferred filter is a pulse-type bag filter. These commercial available filters position a number of filter bags 21 at the air outlet. The air passes through the bags 21 and upwardly through the air outlet 4. Any dried Fowder which has not already dropped to the drying chamber 11 floor 22 accumulates on the outer surfaces of the bags 21. This powder is removed from the bags 21 periodically as air is injected from a separate air source into the inside or filtered side of the bags 21 causing the bags 21 to expand. This counter air flow and the bag 21 expansion knocks any accumulated powder from the air bags 21 onto the floor 22 of the di~eharge end lS of the drying charbor 11 where it `' .
, 1~3;~6~3 is removed by the above described drag system 16 and the auger 17.
The drag system 16 has a pair of stainless steel sanitary chains 24 mounted on end sprockets 25 at the corners of the drying chamber bottom 22. The chains 24 are driven by a suitable electric drive system 26 to move elongated powder dragging flights 27 along the chamber bottom 22 to carry the dried powder to the exit auger 17. The flights 27 are metal such as aluminum or plastic. Support rods 28 are positioned to engage low friction plastic flight support pads 29 as the flights 27 are returned to the start of their powder moving run.
The Air Distribution Plate and Method The air distribution plate 10 provides an efficient mixing of the atomized product spray with the heated drying air. An 'air flow is required which provides a maximum and uniform exposure of the atomized product partiales to the heated drying air. The desired exposure results in a high efficiency drying action whereby relatively lower drying tempera-tures are utilized to protect heat sensitive food products or other products from heat damage.
The air distribution plate 10, in accordance with the present invention, covers substantially the entire air e~try end of the drying chamber 9 and directs a forward flow of air through the drying chamber 11 and generally parallel to the chamber 11 side walls 30, ceiling 31, and floor 22. A number of product atomizing nozzles 12 are mounted on the air distribution plate 10. They are coupled through the supply system 14 to the source of liquid products 23. Each of the atomizing nozzles i2 is mounted downstrea~ from the air distribution plate 10 beyond a relatively large orifice or air nozzle 32. The air nozzles 32 pass air to and past '` ,: ~ ' ' ' ' " ,' ' .
:~13;~6~3 the atomizing nozzles 12 at a relatively high velocity which picks up the ato~ized particles from the atomizing nozzles 12 and begins and completes a major portion of the particle drying.
The air distribution plate 10 also includea a large number of p,enerally uniformly spaced relatively smaller air nozzles 34 which pass a lower velocity of air in air streams surrounding the above described higher velocity air streams from the larger nozzles 32. These lower velocity air streams suppress a back flow or back lash of higher velocity air in zones adjacent to the air distribution plate 10 and eventually blend further downstream with higher velocity air for drying particles in the final stages of the particle drying action. The overalland~ combined action of the high and low velocity streams provides for a uniform drying of the atomized product particles with the relatively long drying period permitting ~inimal air temperatures to be used for the air used in the drying process. For example, a space starting with a plane parallel to and about one foot downstream from the air distribution plate lO to a plane fu~ther downstream from where the spray break~ into atomized droplets, air flow through and immediately surrounding the spray is at relatively high velocity because of the larger nozzle 32 flow in which the spray is positioned. Surrounding the high velocity air from the nozzles 32 is the lower velocity air from nozzles 34 which eventually blends with the high velocity air as both air flows move downsteam. The higher velocity air picks up the spray and does the major portion of the drying. The lower velocity air suppresses back lash of the higher velocity air and of the spray and eventually blends in with the higher velocity air and spray for the final stages of drying the atomized particles.
~3~6~;~
This results in the uniform drying of the particles and allows sufficient drying time for the relatively low drying temperatures.
The controlled heated air drying as described above also has been found to provide for a relatively high product density so that the dried product occupies a minimum space. Improvements in density, for example, to provide a specific gravity of about .50 as contrasted with dried products from other spray dryers of from .30 to .45 have been realized.
The increased density of the product reduces the package size for the processed product. This higher density is beleived to result from the reduced tendency of the atomized particles to agglomerates before drying.
This, in turn~ results from the improved air flow control and the elimination of a back flow or back lash of the partially dried particles which permits particles to come together and to form into lumps of lower overall density.
The illustrated embodiment of an air distribution plate 10 utilizes four spray nozzles 12 where the smaller air nozzles 34 are about 2" in diameter and the large nozzles 32 are about 12" in diameter. The small nozzles are approximately 6" in length and the larger nozzles 32 are approximately two feet long. This array of large and small nozzles not only controls air flow near and beyond the atomizing nozzles, but it also provides for a heated air flow parallel to the drying chamber 11 walls 30, roof 31, and floor 22. An air flow is present a foot or two downstream from the larger nozzles 32 which may be as much as ten times the velocity of the air flow downstream from the smaller air nozzles 34O
~; At a distance from the air distribution plate 1~ as for ~ example, twelve feet downstream, the air flow through the chamb0r 11 cross-; section becomes relatively uniform throughout the cross-section as a result . .
.., ~1336~3 of a blending process of the drying air.
The above described air control is improved by a preferred shaE~ing of the individual air nozzles. As illustrated in Figures 6 and 7, the individual air nozzles 32 and 34 have rounded or flared air outlets 37 and 38 which act both to prevent any build-up of dried product at the outlets and which also provide for a desirable flaring of the air flow from the individual air nozzles 32 and 34.
In the above described nozzles 32 and 34, a satisfactory flare is provided by rounded outlets 37 and 38 having a radius of approximately lo 1/4". The individual nozzles 32 and 34 are mounted in spaced front and rear plates 35 and 36 to which the nozzles 32 and 34 are welded or otherwise fastened.
A typical air distribution plate, such as the above described plate 10 having four nozzles 12 and four large air nozzles 32, will have about 300 of the smaIl air nozzles 34 uniformly spacea o~er the plate 10.
The upstream or air entry portions of the individual nozzles 32 and 34 are conveniently welded or otherwise fastened to outwardly rounded aperture edges 39 on the rear plate 36.
The relative amounts of air flow through the larger and smaller 20 nozzles 32 and 34 may be further adju~ted by using added apertured plates 40 on the smaller nozzles 34. The number and size of apertures in the optional plates 40 is set to provide a desired air flow reduction through the nozzles 34.
It will be seen that an improved air dryer is provided which is particularly useful for drying powdered products including food products where a m nimal drying temperature is desirable. The improved dryer _ _ ~3~ 3 operation including the improved control of the drying air flow also provides for a finished powder product of increased density to provide a f'inished product of reduced volume for more efficient handling and packaging. The dryer has a minimal si~e for the amount of product produced.
As various changes may be made in the form, construction and arrangement of the parts herein without departing from the spirit and scope of the invention and without sacrificing any of its advantages it is to be understood that all matter herein is to be interpreted as illustrative and not in a limiting sense.
' :.
1:~33693 Figure 2 is a front elevational view of a preferred embodiment of the spray drying means in accordance with the pre-sent invention.
Figure 3 is a top plan view of the spray dryer of Figure 2.
Figure 4 is a vertical sectional view of the air distri-bution plate taken along line 4-4 on Figure 2.
Figure 5 is a vertical sectional view of Figure 4 taken along line 5-5 on figure 4.
~ - 2a -~, .
:
~3~3 Figure 6 is an enlarged fragmentary perspective view of the air distribution plate.
Figure 7 is a vertical sectional view of an air distribution plate taken along line 7-7 on Figure 6.
Figure 8 is a perspective view illustrating the product removing drag means.
Figure 9 is a horizontal sectional view taken along line 9-9 on Figure 8.
The improved air dryer and its method of operation will first be described generally with particular reference to Figures 1~ 2 and 3.
While the spray dryer 1, as described below, is conventionally installed in a suitable plant, it is pre~erred that the air being used in the drying operation be supplied from and returned to the outdoor~. For this purpose, the spray dryer 1 has an elongated air inlet ~ for the drying air supply which extends outside of the dryer building 3. Similarly, an elongated air outlet 4 is connected by suitable exhaust piping to the exit end of the spray dryer 1. The dryer 1 includes a heater 5 to raise the ~emperature of the air from inlet 2, under suitable thermostatic control~ to the desired drying temperature~ Air is fed to and through the heater 5 by means of an inlet air blower 6 coupled by suitable ducting 7 to the air heater 5.
The air ;nlet 2 includes a filter housing 8 conta;n;ng a roughing filter and a high efficiency absolute filter of the type commercially used in air flow filtering operations which will remove as much as 99.97% of all contaminants from the incoming air.
The air heater 5 may use heated coils 9 (Figure 3~ or it may employ direct or indirect heating furnace 5 employing suitable fuels such . ~ .
~3;~6~3 as oil or gas.
The heated air is fed downwardly to an air flow manifold 13 which communicates through an air distribution plate 10 to the drying chamber 11 of the dr~er 1. A n~mber of atomizing nozzles 12 are mounted on the air distribution plate 10 which are coupled through an adjustable fluid feed system 14 to a suitable source 23 of the liquid being dried. The construction and operation of the air distribution plate 10 and the related atomizing nozzles 12 will be described in greater detail below.
The drying chamber 11 t~rminates in a discharge end 15 which completes the removal of the dried or powdered product from the air flow permitting the separated air to pass upwardly to the air outlet 4. The dried product drops to the floor of the drying chamber 11 and is moved in the direction of air flow by a drag system 16 to the bottom of the discharge chamber ~5. A horizontal auger 17 carries the dried product to a removal auger 18 which feeds the dried powder to a vibrating sifter 19.
A final removal of any remaining dried product in the air stream is done at an autlet filter 200 h preferred filter is a pulse-type bag filter. These commercial available filters position a number of filter bags 21 at the air outlet. The air passes through the bags 21 and upwardly through the air outlet 4. Any dried Fowder which has not already dropped to the drying chamber 11 floor 22 accumulates on the outer surfaces of the bags 21. This powder is removed from the bags 21 periodically as air is injected from a separate air source into the inside or filtered side of the bags 21 causing the bags 21 to expand. This counter air flow and the bag 21 expansion knocks any accumulated powder from the air bags 21 onto the floor 22 of the di~eharge end lS of the drying charbor 11 where it `' .
, 1~3;~6~3 is removed by the above described drag system 16 and the auger 17.
The drag system 16 has a pair of stainless steel sanitary chains 24 mounted on end sprockets 25 at the corners of the drying chamber bottom 22. The chains 24 are driven by a suitable electric drive system 26 to move elongated powder dragging flights 27 along the chamber bottom 22 to carry the dried powder to the exit auger 17. The flights 27 are metal such as aluminum or plastic. Support rods 28 are positioned to engage low friction plastic flight support pads 29 as the flights 27 are returned to the start of their powder moving run.
The Air Distribution Plate and Method The air distribution plate 10 provides an efficient mixing of the atomized product spray with the heated drying air. An 'air flow is required which provides a maximum and uniform exposure of the atomized product partiales to the heated drying air. The desired exposure results in a high efficiency drying action whereby relatively lower drying tempera-tures are utilized to protect heat sensitive food products or other products from heat damage.
The air distribution plate 10, in accordance with the present invention, covers substantially the entire air e~try end of the drying chamber 9 and directs a forward flow of air through the drying chamber 11 and generally parallel to the chamber 11 side walls 30, ceiling 31, and floor 22. A number of product atomizing nozzles 12 are mounted on the air distribution plate 10. They are coupled through the supply system 14 to the source of liquid products 23. Each of the atomizing nozzles i2 is mounted downstrea~ from the air distribution plate 10 beyond a relatively large orifice or air nozzle 32. The air nozzles 32 pass air to and past '` ,: ~ ' ' ' ' " ,' ' .
:~13;~6~3 the atomizing nozzles 12 at a relatively high velocity which picks up the ato~ized particles from the atomizing nozzles 12 and begins and completes a major portion of the particle drying.
The air distribution plate 10 also includea a large number of p,enerally uniformly spaced relatively smaller air nozzles 34 which pass a lower velocity of air in air streams surrounding the above described higher velocity air streams from the larger nozzles 32. These lower velocity air streams suppress a back flow or back lash of higher velocity air in zones adjacent to the air distribution plate 10 and eventually blend further downstream with higher velocity air for drying particles in the final stages of the particle drying action. The overalland~ combined action of the high and low velocity streams provides for a uniform drying of the atomized product particles with the relatively long drying period permitting ~inimal air temperatures to be used for the air used in the drying process. For example, a space starting with a plane parallel to and about one foot downstream from the air distribution plate lO to a plane fu~ther downstream from where the spray break~ into atomized droplets, air flow through and immediately surrounding the spray is at relatively high velocity because of the larger nozzle 32 flow in which the spray is positioned. Surrounding the high velocity air from the nozzles 32 is the lower velocity air from nozzles 34 which eventually blends with the high velocity air as both air flows move downsteam. The higher velocity air picks up the spray and does the major portion of the drying. The lower velocity air suppresses back lash of the higher velocity air and of the spray and eventually blends in with the higher velocity air and spray for the final stages of drying the atomized particles.
~3~6~;~
This results in the uniform drying of the particles and allows sufficient drying time for the relatively low drying temperatures.
The controlled heated air drying as described above also has been found to provide for a relatively high product density so that the dried product occupies a minimum space. Improvements in density, for example, to provide a specific gravity of about .50 as contrasted with dried products from other spray dryers of from .30 to .45 have been realized.
The increased density of the product reduces the package size for the processed product. This higher density is beleived to result from the reduced tendency of the atomized particles to agglomerates before drying.
This, in turn~ results from the improved air flow control and the elimination of a back flow or back lash of the partially dried particles which permits particles to come together and to form into lumps of lower overall density.
The illustrated embodiment of an air distribution plate 10 utilizes four spray nozzles 12 where the smaller air nozzles 34 are about 2" in diameter and the large nozzles 32 are about 12" in diameter. The small nozzles are approximately 6" in length and the larger nozzles 32 are approximately two feet long. This array of large and small nozzles not only controls air flow near and beyond the atomizing nozzles, but it also provides for a heated air flow parallel to the drying chamber 11 walls 30, roof 31, and floor 22. An air flow is present a foot or two downstream from the larger nozzles 32 which may be as much as ten times the velocity of the air flow downstream from the smaller air nozzles 34O
~; At a distance from the air distribution plate 1~ as for ~ example, twelve feet downstream, the air flow through the chamb0r 11 cross-; section becomes relatively uniform throughout the cross-section as a result . .
.., ~1336~3 of a blending process of the drying air.
The above described air control is improved by a preferred shaE~ing of the individual air nozzles. As illustrated in Figures 6 and 7, the individual air nozzles 32 and 34 have rounded or flared air outlets 37 and 38 which act both to prevent any build-up of dried product at the outlets and which also provide for a desirable flaring of the air flow from the individual air nozzles 32 and 34.
In the above described nozzles 32 and 34, a satisfactory flare is provided by rounded outlets 37 and 38 having a radius of approximately lo 1/4". The individual nozzles 32 and 34 are mounted in spaced front and rear plates 35 and 36 to which the nozzles 32 and 34 are welded or otherwise fastened.
A typical air distribution plate, such as the above described plate 10 having four nozzles 12 and four large air nozzles 32, will have about 300 of the smaIl air nozzles 34 uniformly spacea o~er the plate 10.
The upstream or air entry portions of the individual nozzles 32 and 34 are conveniently welded or otherwise fastened to outwardly rounded aperture edges 39 on the rear plate 36.
The relative amounts of air flow through the larger and smaller 20 nozzles 32 and 34 may be further adju~ted by using added apertured plates 40 on the smaller nozzles 34. The number and size of apertures in the optional plates 40 is set to provide a desired air flow reduction through the nozzles 34.
It will be seen that an improved air dryer is provided which is particularly useful for drying powdered products including food products where a m nimal drying temperature is desirable. The improved dryer _ _ ~3~ 3 operation including the improved control of the drying air flow also provides for a finished powder product of increased density to provide a f'inished product of reduced volume for more efficient handling and packaging. The dryer has a minimal si~e for the amount of product produced.
As various changes may be made in the form, construction and arrangement of the parts herein without departing from the spirit and scope of the invention and without sacrificing any of its advantages it is to be understood that all matter herein is to be interpreted as illustrative and not in a limiting sense.
Claims (5)
1. An improved air distribution plate for positioning in a hot air dryer between an air supply manifold and a drying chamber for distributing air into said drying chamber into an initial flow pattern of generally parallel streams of differing velocity and thereafter of a single blended stream of uniform velocity across the stream the combination of:
a flat plate member;
a plurality of elongated first tubular nozzles mounted in spaced positions in said plate;
a plurality of relatively shorter and smaller diameter second elongated tubular nozzles mounted throughout said plate with generally uniform spacing and surrounding said first nozzles;
said first and second nozzles having their axes positioned perpendicularly to said flat plate;
fluid atomizers mounted beyond the air outlets of said first nozzles, and means at the air exit ends of said first and second nozzles for causing the air flowing from said second nozzles to flare.
a flat plate member;
a plurality of elongated first tubular nozzles mounted in spaced positions in said plate;
a plurality of relatively shorter and smaller diameter second elongated tubular nozzles mounted throughout said plate with generally uniform spacing and surrounding said first nozzles;
said first and second nozzles having their axes positioned perpendicularly to said flat plate;
fluid atomizers mounted beyond the air outlets of said first nozzles, and means at the air exit ends of said first and second nozzles for causing the air flowing from said second nozzles to flare.
2. The plate as claimed in claim 1 in which the cross-section of said first nozzle is at least several times as great as the cross-section of said second nozzle.
3. The plate as claimed in claim 1 in which said first nozzles are three or more times longer than said second nozzles.
4. An improved method of spray drying liquid product comprising the steps of:
passing heated drying air from a manifold to a drying chamber;
initially distributing the air during the said passage into a plurality of larger flowing streams of heated air surrounded by a greater number of smaller flowing streams of heated air of relatively smaller cross-section and lower velocity;
spraying the liquid product into said larger flowing streams, and causing said larger and smaller flowing streams to flare slightly initially and to thereby blend together further down-stream to form a final stream of uniform velocity in cross-section,
passing heated drying air from a manifold to a drying chamber;
initially distributing the air during the said passage into a plurality of larger flowing streams of heated air surrounded by a greater number of smaller flowing streams of heated air of relatively smaller cross-section and lower velocity;
spraying the liquid product into said larger flowing streams, and causing said larger and smaller flowing streams to flare slightly initially and to thereby blend together further down-stream to form a final stream of uniform velocity in cross-section,
5. The method as claimed in claim 4 which further comprises the step of spraying the liquid product into said larger flowing stream beyond the air distribution into the larger and smaller flowing streams.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US82863477A | 1977-08-29 | 1977-08-29 | |
| US828,634 | 1977-08-29 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1133693A true CA1133693A (en) | 1982-10-19 |
Family
ID=25252337
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA310,158A Expired CA1133693A (en) | 1977-08-29 | 1978-08-28 | Spray dryer |
Country Status (14)
| Country | Link |
|---|---|
| JP (1) | JPS5445678A (en) |
| AT (1) | AT365048B (en) |
| BE (1) | BE870001A (en) |
| CA (1) | CA1133693A (en) |
| DE (1) | DE2836712A1 (en) |
| ES (1) | ES472901A1 (en) |
| FR (1) | FR2401682B1 (en) |
| GB (1) | GB2003042B (en) |
| IE (1) | IE47259B1 (en) |
| LU (1) | LU80164A1 (en) |
| NL (1) | NL191109C (en) |
| NZ (1) | NZ188155A (en) |
| SE (1) | SE449397B (en) |
| ZA (1) | ZA784795B (en) |
Families Citing this family (18)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2534008B1 (en) * | 1982-09-30 | 1987-03-06 | Henningsen Foods | AIR DISTRIBUTION DEVICE FOR HOT AIR DRYER AND DRYER |
| DE3301872A1 (en) * | 1983-01-21 | 1984-07-26 | Henkel KGaA, 4000 Düsseldorf | SPRAY DRYER AND METHOD FOR OPERATING THE DRYER |
| DE19508657A1 (en) * | 1995-03-14 | 1996-09-19 | Ohlmann Anlagen Und Maschinenb | Spray nozzle in a spray-dry installation |
| US5851575A (en) * | 1997-04-29 | 1998-12-22 | Griffin Industries, Inc. | Method for drying and processing raw food material |
| EP2056037A1 (en) * | 2007-10-30 | 2009-05-06 | Büchi Labortechnik AG | Heating, method for heating and laminating, electrostatic separator, spray drier, separating device and method for separating particles |
| JP5760214B2 (en) * | 2008-06-12 | 2015-08-05 | ナノミストテクノロジーズ株式会社 | Solution concentrator |
| US9867782B2 (en) | 2009-04-09 | 2018-01-16 | Entegrion, Inc. | Spray-dried blood products and methods of making same |
| US8407912B2 (en) | 2010-09-16 | 2013-04-02 | Velico Medical, Inc. | Spray dried human plasma |
| US20110142885A1 (en) | 2009-09-16 | 2011-06-16 | Velico Medical, Inc. | Spray-dried human plasma |
| JP2013544181A (en) | 2010-10-29 | 2013-12-12 | ベリコ メディカル インコーポレイティッド | System and method for spray drying liquids |
| US20140083628A1 (en) | 2012-09-27 | 2014-03-27 | Velico Medical, Inc. | Spray drier assembly for automated spray drying |
| US20160256794A1 (en) * | 2013-10-24 | 2016-09-08 | Spx Flow Technology Danmark A/S | Gas distributer for a convective dryer having improved radial gas velocity control |
| WO2015177324A1 (en) * | 2014-05-21 | 2015-11-26 | Spx Flow Technology Danmark A/S | Gas distributer for a convective dryer having improved radial gas velocity control |
| US9561184B2 (en) | 2014-09-19 | 2017-02-07 | Velico Medical, Inc. | Methods and systems for multi-stage drying of plasma |
| US11998861B2 (en) | 2022-09-15 | 2024-06-04 | Velico Medical, Inc. | Usability of a disposable for a spray drying plasma system |
| US11975274B2 (en) | 2022-09-15 | 2024-05-07 | Velico Medical, Inc. | Blood plasma product |
| US11841189B1 (en) | 2022-09-15 | 2023-12-12 | Velico Medical, Inc. | Disposable for a spray drying system |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1624739A (en) * | 1926-06-18 | 1927-04-12 | Ind Associates Inc | Spray drying |
| GB438249A (en) * | 1935-04-08 | 1935-11-13 | Rubber Latex Poeder Cie N V | Apparatus for converting milky liquids, latices, solutions, dispersions and emulsions into a finely divided solid condition by centrifugal spraying and drying |
| US2835597A (en) * | 1954-12-10 | 1958-05-20 | Barzelay Martin E | Spray drying process |
| US2957519A (en) * | 1957-11-12 | 1960-10-25 | John G Hoad | Spray drying apparatus and method |
| DE1198742B (en) * | 1961-11-20 | 1965-08-12 | Dr Max E Schulz | Operating method for atomization dryers with housings in lightweight construction |
| DE1199191B (en) * | 1963-02-02 | 1965-08-19 | Krauss Maffei Ag | Atomization dryer with a vertical axis |
| GB1204746A (en) * | 1968-03-22 | 1970-09-09 | Inst Luft Und Kaltetechnik | A drier for spray drying and crystallation |
| FR1576569A (en) * | 1968-06-04 | 1969-08-01 | ||
| US3648753A (en) * | 1969-08-13 | 1972-03-14 | Henningsen Foods | Spray dryer air flow control |
| US3803723A (en) * | 1971-07-15 | 1974-04-16 | B Shteinfeld | Device for introducing a gaseous agent |
-
1978
- 1978-08-15 NZ NZ188155A patent/NZ188155A/en unknown
- 1978-08-18 GB GB7833828A patent/GB2003042B/en not_active Expired
- 1978-08-21 NL NL7808615A patent/NL191109C/en not_active IP Right Cessation
- 1978-08-22 DE DE19782836712 patent/DE2836712A1/en not_active Ceased
- 1978-08-23 ZA ZA00784795A patent/ZA784795B/en unknown
- 1978-08-28 BE BE190091A patent/BE870001A/en not_active IP Right Cessation
- 1978-08-28 LU LU80164A patent/LU80164A1/xx unknown
- 1978-08-28 CA CA310,158A patent/CA1133693A/en not_active Expired
- 1978-08-28 FR FR7824770A patent/FR2401682B1/en not_active Expired
- 1978-08-28 AT AT0623778A patent/AT365048B/en not_active IP Right Cessation
- 1978-08-28 SE SE7809034A patent/SE449397B/en not_active IP Right Cessation
- 1978-08-29 JP JP10449378A patent/JPS5445678A/en active Granted
- 1978-08-29 ES ES472901A patent/ES472901A1/en not_active Expired
- 1978-08-29 IE IE1745/78A patent/IE47259B1/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| FR2401682A1 (en) | 1979-03-30 |
| BE870001A (en) | 1978-12-18 |
| SE7809034L (en) | 1979-03-01 |
| SE449397B (en) | 1987-04-27 |
| NL191109B (en) | 1994-09-01 |
| LU80164A1 (en) | 1979-01-19 |
| ATA623778A (en) | 1981-05-15 |
| ES472901A1 (en) | 1979-10-16 |
| NZ188155A (en) | 1981-12-15 |
| GB2003042A (en) | 1979-03-07 |
| AT365048B (en) | 1981-12-10 |
| ZA784795B (en) | 1979-08-29 |
| GB2003042B (en) | 1982-09-02 |
| NL191109C (en) | 1995-02-01 |
| JPS5445678A (en) | 1979-04-11 |
| DE2836712A1 (en) | 1979-03-08 |
| IE47259B1 (en) | 1984-02-08 |
| IE781745L (en) | 1979-02-28 |
| FR2401682B1 (en) | 1985-12-27 |
| JPS62721B2 (en) | 1987-01-09 |
| NL7808615A (en) | 1979-03-02 |
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| MKEX | Expiry |