HYDROLYZING APPARATUS
United States Patent 3617313
There is provided a method and apparatus for the continuous process hydrolyzing under pressure of fibrous material such as the byproducts of poultry--feathers, blood, offal, hair, and the like. The hydrolyzing takes place within a pressure vessel and inlet means are provided for continuously introducing the untreated material into the vessel while the vessel is maintained under pressure. This is accomplished by compressing the untreated material into a substantially pressure-impervious plug which moves through the inlet passageway continuously into the pressure vessel. Discharge means are also provided for releasing the treated material continuously from the pressure vessel while the pressure vessel is maintained under pressure.
US Patent References:
Process and apparatus for treating vegetable substances
Mabee - December 1925 - 1565282
Method and apparatus for hydrolyzing cellulosic materials
Wallace - June 1954 - 2681871
Conversion of feathers
Mayer - February 1955 - 2702245
Method and apparatus for hydrolyzing cellulosic materials
Wallace et al. - March 1956 - 2739086
Apparatus for processing fatcontaining solids
Hickey et al. - August 1966 - 3263592
Process and apparatus for treating vegetable substances
Mabee - December 1925 - 1565282
Method and apparatus for hydrolyzing cellulosic materials
Wallace - June 1954 - 2681871
Conversion of feathers
Mayer - February 1955 - 2702245
Method and apparatus for hydrolyzing cellulosic materials
Wallace et al. - March 1956 - 2739086
Apparatus for processing fatcontaining solids
Hickey et al. - August 1966 - 3263592
Inventors:
Harrington Jr., Bert S. (Chamblee, GA)
Vojacek Jr., Joseph (Brookfield, IL)
Vojacek Jr., Joseph (Brookfield, IL)
Application Number:
04/689186
Publication Date:
11/02/1971
Filing Date:
12/08/1967
View Patent Images:
Export Citation:
Assignee:
Chemetron Corporation (Chicago, IL)
Primary Class:
Other Classes:
99/360
International Classes:
A23J1/00; A23J1/06; A23J1/10; A23J3/30; A23K1/10; A23J3/00; A23K1/10
Field of Search:
99/2,7,10,8,211,216,251,1,235 127/1,36
US Patent References:
Primary Examiner:
Yudkoff, Norman
Assistant Examiner:
Ribando, Curtis P.
Claims:
What is claimed as new and desired to be secured by Letters Patent of the United States is
1. An apparatus for the continuous processing of a material under pressure comprising: a pressure vessel having a cylindrical first wall defining an elongated tubular processing chamber and a second wall completely encompassing the first wall and defining a jacket in heat exchange relationship to and not in fluid communication with said processing chamber; inlet passage means for continuously introducing untreated material into said processing chamber; discharge passage means for continuously discharging treated material from said vessel; sealing means for continuously compressing the untreated material into a substantially pressure-impervious plug in said inlet passage means to define a pressure seal; a rotary shaft mounted coaxially within said processing chamber and a plurality of straight relatively long blades radially spaced from said shaft and mounted to said shaft on relatively short radial arms for conjoint rotation to agitate the material in said processing chamber, each of said blades having a substantially L-shaped cross section and having a straight outer edge substantially parallel to said shaft and in close proximity to said cylindrical first wall with any point on said edge equidistant from said cylindrical first wall during a complete rotation of said shaft; means for providing a continuous flow of steam within said processing chamber; means for providing a continuous flow of fluid within said jacket; and pressure release means for continuously releasing the treated material from said discharge passage means while maintaining the pressure within said processing chamber.
2. An apparatus as set forth in claim 1 including mechanical breaking means in said inlet passage means for continuously breaking up said plug as it advances into said processing chamber.
3. An apparatus as set forth in claim 1 including means for introducing reagents into said vessel to mix with the material flowing therethrough.
4. An apparatus as set forth in claim 1 wherein said sealing means includes a worm conveyor effective to compress the material and partially separate liquids therefrom.
5. An apparatus as set forth in claim 4 including means reintroducing said liquids into the pressure system downstream of the plug.
6. An apparatus as set forth in claim 4 wherein said worm conveyor is of decreasing pitch.
7. An apparatus as set forth in claim 4 wherein said worm conveyor discharges the plug into an outwardly tapered portion of the inlet passage means.
8. An apparatus as set forth in claim 1 wherein said pressure release means includes expansion means in said discharge passage means.
9. An apparatus as set forth in claim 1 including a vapor separator connected to said discharge passage means.
10. An apparatus as set forth in claim 9 including a condenser connected to said vapor separator.
11. An apparatus as set forth in claim 2 including means for introducing reagents into said processing chamber to mix with the material flowing therethrough adjacent the location where the plug is being broken up.
12. The apparatus of claim 1 wherein said blades are canted relative to said shaft to advance the material through said processing chamber.
1. An apparatus for the continuous processing of a material under pressure comprising: a pressure vessel having a cylindrical first wall defining an elongated tubular processing chamber and a second wall completely encompassing the first wall and defining a jacket in heat exchange relationship to and not in fluid communication with said processing chamber; inlet passage means for continuously introducing untreated material into said processing chamber; discharge passage means for continuously discharging treated material from said vessel; sealing means for continuously compressing the untreated material into a substantially pressure-impervious plug in said inlet passage means to define a pressure seal; a rotary shaft mounted coaxially within said processing chamber and a plurality of straight relatively long blades radially spaced from said shaft and mounted to said shaft on relatively short radial arms for conjoint rotation to agitate the material in said processing chamber, each of said blades having a substantially L-shaped cross section and having a straight outer edge substantially parallel to said shaft and in close proximity to said cylindrical first wall with any point on said edge equidistant from said cylindrical first wall during a complete rotation of said shaft; means for providing a continuous flow of steam within said processing chamber; means for providing a continuous flow of fluid within said jacket; and pressure release means for continuously releasing the treated material from said discharge passage means while maintaining the pressure within said processing chamber.
2. An apparatus as set forth in claim 1 including mechanical breaking means in said inlet passage means for continuously breaking up said plug as it advances into said processing chamber.
3. An apparatus as set forth in claim 1 including means for introducing reagents into said vessel to mix with the material flowing therethrough.
4. An apparatus as set forth in claim 1 wherein said sealing means includes a worm conveyor effective to compress the material and partially separate liquids therefrom.
5. An apparatus as set forth in claim 4 including means reintroducing said liquids into the pressure system downstream of the plug.
6. An apparatus as set forth in claim 4 wherein said worm conveyor is of decreasing pitch.
7. An apparatus as set forth in claim 4 wherein said worm conveyor discharges the plug into an outwardly tapered portion of the inlet passage means.
8. An apparatus as set forth in claim 1 wherein said pressure release means includes expansion means in said discharge passage means.
9. An apparatus as set forth in claim 1 including a vapor separator connected to said discharge passage means.
10. An apparatus as set forth in claim 9 including a condenser connected to said vapor separator.
11. An apparatus as set forth in claim 2 including means for introducing reagents into said processing chamber to mix with the material flowing therethrough adjacent the location where the plug is being broken up.
12. The apparatus of claim 1 wherein said blades are canted relative to said shaft to advance the material through said processing chamber.
Description:
This invention relates to a new and improved method and apparatus for the hydrolyzation or treatment under pressure of fibrous materials, and particularly of the byproducts of slaughter plants such as the feathers, blood, and offal of poultry.
In order to realize all the income potential it is necessary for slaughterhouses to utilize the byproducts of the slaughter plants to the maximum extent possible. Heretofore the commercial practice in slaughtering poultry, for example, has varied considerably in the amount of utilization of the byproducts from the poultry. Such poultry byproducts and wastes accumulate at every slaughtering plant and must usually be removed daily. Recoverable inedible byproducts such as blood, feathers and offal, comprise up to 30 percent of the liveweight of all poultry killed. Accordingly it has been known commercially to collect such inedible byproducts and to render the products through the process of hydrolysis so as to break down the protein content into a digestible meal for poultry and other animals. However heretofore such hydrolysis of poultry byproducts has been slow and expensive and has not provided the best possible yield. Accordingly many slaughter plants discarded or gave away their poultry byproducts rather than realize any financial return for their use.
The former methods of conversion of the poultry inedibles, such as the conversion of feathers to an edible and otherwise useable substance high in protein and carbohydrates, and low in fiber and cellulose, was generally carried on by the batch method wherein they were maintained in a temperature of about 250° F. and about 30 pounds steam pressure gage for a period of 11/2 hours or longer so as to break down the edible organic materials therein. Such batch operation was slow, time consuming, and expensive so that conversion of these inedible products to feed was conducted only in the areas of the large slaughter plants in the commercial poultry areas. Moreover, it is necessary to exclude air from the hydrolyzing chamber since oxidation of the material readily takes place at the elevated temperatures and pressures which adversely affects the quality of the finished feed. Additionally it is necessary to provide a controlled moisture content in order to provide uniform quality of finished product.
Accordingly it is an object of the present invention to provide a new and improved apparatus for the treatment of fibrous material.
Another object of the present invention is the provision of a new and improved method for the treatment of fibrous material.
Another object of the present invention is the provision of a new and improved apparatus for the hydrolysis of waste fibrous materials.
Yet a further and more specific object of the present invention is the provision of a new and improved feeding apparatus for the hydrolysis of poultry feathers and other wastes in a continuous operation.
Yet a further object of the present invention is the provision of a new and improved feeding apparatus for the conversion of fibrous material which overcomes the difficulties mentioned above.
Still another object is the provision of an improved method of feeding fibrous material into a pressure hydrolyzing vessel.
Further objects and advantages of the present invention will become apparent as the following description proceeds and the features of novelty which characterize the invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.
In accordance with these and many other objects of the present invention there is provided an improved apparatus for the continuous process hydrolyzing under pressure of fibrous material such as that resulting from poultry wastes at a slaughterhouse. The hydrolyzing takes place within a pressure vessel defining a hydrolyzing chamber. Inlet passage means are provided to the vessel for continuously introducing untreated fibrous material into the vessel and discharge passage means are provided for continuously discharging the treated material from the vessel. Suitable means are provided for continuously compressing the untreated material into a substantially pressure impervious plug within the inlet passage to provide a pressure seal, and pressure release means are provided for continuously releasing the treated material from the discharge passage means. To provide for rapid hydrolysis in the hydrolyzing chamber, the plug is broken up and fluffed or shredded as it passes into the hydrolyzing chamber. In this manner it is possible to continuously feed the material to be treated through the hydrolyzing chamber while it is maintained under pressure.
This invention also relates to an improved method of continuously hydrolyzing a fibrous material under pressure including compacting the fibrous material to form a pressure-impervious seal in the inlet passage of the hydrolyzing chamber and breaking and shredding the material to pass into the hydrolyzing chamber.
Advantageously the compression of the material according to the present invention provides an air-free plug excluding air from the hydrolyzing chamber. Additionally the compressing of the untreated bulk material into the substantially pressure-impervious plug extracts an amount of liquid from the material which will result in a determined amount of liquid in the raw fibrous material. A controlled amount of this liquid, which may be in part water, blood, or other materials, may be reintroduced into the pressure system at the combined fluffer and mixer assembly or other desired point. According to the present invention the process may be carried on in the pressure range of 70 pounds per square inch gage and above, and temperature ranges in the area of 300° and above. It has been found that at 70 pounds per square inch gage, and at the corresponding saturation temperature and above, the quality of protein that results from the hydrolysis process is substantially improved. Thus the method and apparatus according to the present invention produces an end product which has greater quantity and higher quality of protein and other food values and more accurately controlled moisture content than has heretofore been commercially produced.
For a better understanding of the present invention, reference may be had to the accompanying drawings wherein:
FIG. 1 is a somewhat schematic representation of a hydrolyzing apparatus according to the present invention;
FIG. 2 is a plan view, in broken away section, of the new and improved hydrolyzing apparatus;
FIG. 3 is a pictorial view of the agitator in the hydrolyzing chamber, taken along line 3--3 of FIG. 2;
FIG. 4 is a cross-sectional view of the feed arrangement for the hydrolyzer apparatus, taken along line 4-4 of FIG. 2;
FIG. 5 is a cross-sectional view of the fluffer or chipper in the material feed portion of the hydrolyzing apparatus, taken substantially along line 5-5 of FIG. 4;
FIG. 6 is a cross-sectional view of the pressure vessel taken substantially along its longitudinal axis; and
FIGS. 7, 8 and 9 are cross-sectional views of the pressure vessel of FIG. 6 taken along lines 7--7, 8--8, and 9--9, respectively of FIG. 6.
Referring now to the drawings, there is illustrated an improved hydrolyzing apparatus 10 for the treatment or hydrolyzing under pressure of fibrous material such as poultry wastes in the form of feathers, blood, offal and the like. Specifically the hydrolyzing apparatus 10 includes a feed portion 12, FIGS. 1, 2, 4 and 5, and a discharge portion 14, each operatively connected with a pressure vessel forming a hydrolyzing chamber 16. The fibrous material to be treated is introduced into a bin or hopper 18 in any suitable manner as by a belt conveyor 19. Such fibrous materials may include the bulk wastes from a slaughter plant such as the feathers and offal of poultry. It is understood that fibrous materials other than poultry wastes may be processed by the apparatus of the present invention. Such solid materials as are introduced within the bin 18 contain a substantial quantity of liquids, particularly water and blood, and additionally will entrap substantial quantities of air. In order to reduce the liquids and air from the fibrous materials, the fibrous materials are compressed in any suitable manner as with a screw conveyor 20 driven by a feed motor 21 through a suitable belt drive 22. In illustrated embodiment the screw conveyor 20 is preferably of the variable pitch type, having progressively closer pitch toward the discharge end thereof, thus aiding in the compression of the fibrous material. The compressed material discharges from the screw conveyor 20 into an inlet passageway 23, preferably tapered outwardly, in the feed portion 12 of the hydrolyzing apparatus. At this time the fibrous material has taken on the form of a pressure-impervious plug 24, substantially free of air, with much of the liquid thereof squeezed out and collected from the bottom of the bin through a liquid discharge 25.
Hydrolysis occurs more quickly on small particles than on large particles, and there is provided a fluffer and mixer or shredder assembly 28 effective to break the plug 24 up into small particles. To this end the fluffer and mixer assembly 28 contains a plurality of rotatable blades 29 driven in close proximity to the inner wall of the fluffer shell by a suitable drive motor 30 and belt drive 32. Since the plug 24 defines a pressure seal in the feed portion 12, the fluffer and mixer assembly may be maintained under suitable pressure and temperature to begin the hydrolysis process. To this end a metered amount of reaction material such as steam may be introduced into the inner cavity of the fluffer and mixer assembly through a suitable steam injection inlet 32. Additionally any liquids to undergo the hydrolyzing process, such as those liquids obtained from the liquid discharge 25 at the bottom of the bin 18, may be metered into the pressurized fluffer chamber through a liquid inlet 34 in the fluffer assembly 28 in the suitable proportions to provide a desired and controllable moisture content.
The blades 29 of the fluffer and mixing assembly 28 may comprise angularly and axially spaced eccentrics each having an outer arcuate surface 29a rotatable in close proximity to the inner surface of the fluffer shell. Each blade 29 additionally has concave sidewalls 29b to provide cutting edges 29c. A pair of shields 29d, FIG. 5, outward of the blades 29 protects the packing section 37 of the fluffer and mixing assembly from solid particles of the fibrous material.
The fluffed or shredded material drops by gravity through a discharge opening 38, FIG. 4, in the bottom of the fluffer and mixer assembly 28 into the inlet end of the hydrolyzer chamber 16 through a material inlet 46. The hydrolyzer chamber 16 is, of course, a pressure device wherein the liquid and fibrous material is subjected to the hydrolyzing action of heat and steam. It has been found that a wet steam at a pressure of about 100 pounds per square inch gage, introduced into the fluffer and mixer assembly, or, if desired through suitable steam inlets 47 in the hydrolyzer chamber 16, will be effective to treat poultry materials in approximately 6 minutes. The hydrolyzer chamber 16 is provided with suitable blades or agitators 49 for agitating the material therein to obtain the most rapid hydrolyzing thereof, and additionally, the blades 49 are canted to provide a forward thrust to impel the materials along through the tube of the chamber. The blades 49 are mounted to a rotary shaft 50 driven by a variable speed motor 51 through a belt drive 52. Regulation of the retention time therefore may readily be accomplished through the combined control of the discharge means, as well as by the variation of the speed of rotation of the blades 49. If desired, a steam jacket 48 may surround the chamber 16 to conserve or add heat as desired.
At the completion of the hydrolyzing process, the treated material is discharged from the hydrolyzing chamber at a metered rate to further control the rate of flow of the material through the hydrolyzing chamber. The material must also be reduced in pressure to atmospheric, vapor must be removed, and the material must be dried for use. To this end a discharge 62 pressure feeds into the inlet of a discharge pump 65 driven by a variable speed motor 66. The pump 65 serves as a metering device to regulate the rate of discharge from the hydrolyzing chamber 16. The pump may be regulated to discharge at a desired pressure lower than the feed pressure thereto from the hydrolyzing chamber. The pump 65 discharges through a suitable conduit 67. Because the critical temperature of the material has been substantially lowered due to the lowering of the pressure acting thereon, some, if not all, of the water mixed with the product will be vaporized. The material may then be passed through a vapor separator 68 if desired which may be of the centrifugal type. The vapor is bled off through a vapor outlet 70 and may be passed into a suitable condenser 71. The condenser 71, of course, may establish a sufficient vacuum so that the vapor separator 68 discharges to below atmospheric pressure thus causing a larger conversion of the wet steam of water into vapor. The condenser 71 illustrated in FIG. 1 is of the barometric condensing type which herein cooling water is supplied to a water inlet 72 and the condensed vapor and water combined discharge through a condensate tube 73. The liquid material, or the solids in liquid suspension, passes from the vapor separator 68 through a discharge conduit 74 and into a dryer 75 where sufficient additional moisture may be driven from the treated material to provide the desired moisture content.
If desired the material discharged from the dryer may be passed through a screen 80 to separate out the fines where they will fall into a bin 81. The material which does not pass through the screen 80 may be passed through a grinder 82.
From the above detailed description of the hydrolyzing apparatus, the improved method is believed clear. However, briefly, it is understood that the improved method relates to the continuous hydrolyzing under pressure of a fibrous material in a pressure vessel defining a hydrolyzing chamber. In accordance with the present invention the fibrous material is first compacted in the inlet passage to provide a pressure-impervious seal which advantageously may be in the form of a plug. Air may be removed from the fibrous material in its formation of the pressure seal, and additionally liquids may be extracted from the material. If desired the liquids may be reintroduced into the pressure system downstream of the seal. After formation of the seal, the plug is removed downstream where it is continuously broken and shredded to pass as shredded material into the hydrolizing chamber. After the hydrolyzing is completed by the addition of water or other catalyst under high pressure and temperature, the treated material is removed from the hydrolyzing chamber through a pressure seal.
Advantageously the method and apparatus according to the present invention provides improved hydrolyzing of fibrous material such as slaughterhouse wastes or byproducts in a continuous pressure process with a minimum loss of pressure in the pressurized hydrolyzing chamber. The hydrolyzing may take place at a temperature in excess of 70 pounds per square inch gage. Since it has been found that the hydrolyzing of fibrous products intended for use as animal meal produces improved quality and quantity of digestible proteins and other ingredients above the pressure and temperature of wet steam at about 70 pounds per square inch gage, the apparatus according to the present invention produces a superior product compared to that generally available commercially. The low cost and rapid processing of the material permits economical operation of the hydrolyzing apparatus so as to dispose of the slaughter house byproducts in the most advantageous and economical manner.
Although the present invention has been described by way of a single embodiment thereof, it will be understood that numerous other embodiments and modifications may be made which come within the spirit and scope of the present invention. For example, the hydrolyzing apparatus may be used for the treatment of materials other than slaughterhouse wastes, although the above description has been made with reference to byproducts of poultry slaughterhouses. Moreover the discharge from the hydrolyzing chamber may be in any manner which will bring the material to atmospheric pressure, vaporizing to the extent possible the water contained in the treated product, and drying the treated product to the desired moisture content. To this end the pump 65 may be eliminated and throttling and metering of the material take place at the expansion valve 68.
In order to realize all the income potential it is necessary for slaughterhouses to utilize the byproducts of the slaughter plants to the maximum extent possible. Heretofore the commercial practice in slaughtering poultry, for example, has varied considerably in the amount of utilization of the byproducts from the poultry. Such poultry byproducts and wastes accumulate at every slaughtering plant and must usually be removed daily. Recoverable inedible byproducts such as blood, feathers and offal, comprise up to 30 percent of the liveweight of all poultry killed. Accordingly it has been known commercially to collect such inedible byproducts and to render the products through the process of hydrolysis so as to break down the protein content into a digestible meal for poultry and other animals. However heretofore such hydrolysis of poultry byproducts has been slow and expensive and has not provided the best possible yield. Accordingly many slaughter plants discarded or gave away their poultry byproducts rather than realize any financial return for their use.
The former methods of conversion of the poultry inedibles, such as the conversion of feathers to an edible and otherwise useable substance high in protein and carbohydrates, and low in fiber and cellulose, was generally carried on by the batch method wherein they were maintained in a temperature of about 250° F. and about 30 pounds steam pressure gage for a period of 11/2 hours or longer so as to break down the edible organic materials therein. Such batch operation was slow, time consuming, and expensive so that conversion of these inedible products to feed was conducted only in the areas of the large slaughter plants in the commercial poultry areas. Moreover, it is necessary to exclude air from the hydrolyzing chamber since oxidation of the material readily takes place at the elevated temperatures and pressures which adversely affects the quality of the finished feed. Additionally it is necessary to provide a controlled moisture content in order to provide uniform quality of finished product.
Accordingly it is an object of the present invention to provide a new and improved apparatus for the treatment of fibrous material.
Another object of the present invention is the provision of a new and improved method for the treatment of fibrous material.
Another object of the present invention is the provision of a new and improved apparatus for the hydrolysis of waste fibrous materials.
Yet a further and more specific object of the present invention is the provision of a new and improved feeding apparatus for the hydrolysis of poultry feathers and other wastes in a continuous operation.
Yet a further object of the present invention is the provision of a new and improved feeding apparatus for the conversion of fibrous material which overcomes the difficulties mentioned above.
Still another object is the provision of an improved method of feeding fibrous material into a pressure hydrolyzing vessel.
Further objects and advantages of the present invention will become apparent as the following description proceeds and the features of novelty which characterize the invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.
In accordance with these and many other objects of the present invention there is provided an improved apparatus for the continuous process hydrolyzing under pressure of fibrous material such as that resulting from poultry wastes at a slaughterhouse. The hydrolyzing takes place within a pressure vessel defining a hydrolyzing chamber. Inlet passage means are provided to the vessel for continuously introducing untreated fibrous material into the vessel and discharge passage means are provided for continuously discharging the treated material from the vessel. Suitable means are provided for continuously compressing the untreated material into a substantially pressure impervious plug within the inlet passage to provide a pressure seal, and pressure release means are provided for continuously releasing the treated material from the discharge passage means. To provide for rapid hydrolysis in the hydrolyzing chamber, the plug is broken up and fluffed or shredded as it passes into the hydrolyzing chamber. In this manner it is possible to continuously feed the material to be treated through the hydrolyzing chamber while it is maintained under pressure.
This invention also relates to an improved method of continuously hydrolyzing a fibrous material under pressure including compacting the fibrous material to form a pressure-impervious seal in the inlet passage of the hydrolyzing chamber and breaking and shredding the material to pass into the hydrolyzing chamber.
Advantageously the compression of the material according to the present invention provides an air-free plug excluding air from the hydrolyzing chamber. Additionally the compressing of the untreated bulk material into the substantially pressure-impervious plug extracts an amount of liquid from the material which will result in a determined amount of liquid in the raw fibrous material. A controlled amount of this liquid, which may be in part water, blood, or other materials, may be reintroduced into the pressure system at the combined fluffer and mixer assembly or other desired point. According to the present invention the process may be carried on in the pressure range of 70 pounds per square inch gage and above, and temperature ranges in the area of 300° and above. It has been found that at 70 pounds per square inch gage, and at the corresponding saturation temperature and above, the quality of protein that results from the hydrolysis process is substantially improved. Thus the method and apparatus according to the present invention produces an end product which has greater quantity and higher quality of protein and other food values and more accurately controlled moisture content than has heretofore been commercially produced.
For a better understanding of the present invention, reference may be had to the accompanying drawings wherein:
FIG. 1 is a somewhat schematic representation of a hydrolyzing apparatus according to the present invention;
FIG. 2 is a plan view, in broken away section, of the new and improved hydrolyzing apparatus;
FIG. 3 is a pictorial view of the agitator in the hydrolyzing chamber, taken along line 3--3 of FIG. 2;
FIG. 4 is a cross-sectional view of the feed arrangement for the hydrolyzer apparatus, taken along line 4-4 of FIG. 2;
FIG. 5 is a cross-sectional view of the fluffer or chipper in the material feed portion of the hydrolyzing apparatus, taken substantially along line 5-5 of FIG. 4;
FIG. 6 is a cross-sectional view of the pressure vessel taken substantially along its longitudinal axis; and
FIGS. 7, 8 and 9 are cross-sectional views of the pressure vessel of FIG. 6 taken along lines 7--7, 8--8, and 9--9, respectively of FIG. 6.
Referring now to the drawings, there is illustrated an improved hydrolyzing apparatus 10 for the treatment or hydrolyzing under pressure of fibrous material such as poultry wastes in the form of feathers, blood, offal and the like. Specifically the hydrolyzing apparatus 10 includes a feed portion 12, FIGS. 1, 2, 4 and 5, and a discharge portion 14, each operatively connected with a pressure vessel forming a hydrolyzing chamber 16. The fibrous material to be treated is introduced into a bin or hopper 18 in any suitable manner as by a belt conveyor 19. Such fibrous materials may include the bulk wastes from a slaughter plant such as the feathers and offal of poultry. It is understood that fibrous materials other than poultry wastes may be processed by the apparatus of the present invention. Such solid materials as are introduced within the bin 18 contain a substantial quantity of liquids, particularly water and blood, and additionally will entrap substantial quantities of air. In order to reduce the liquids and air from the fibrous materials, the fibrous materials are compressed in any suitable manner as with a screw conveyor 20 driven by a feed motor 21 through a suitable belt drive 22. In illustrated embodiment the screw conveyor 20 is preferably of the variable pitch type, having progressively closer pitch toward the discharge end thereof, thus aiding in the compression of the fibrous material. The compressed material discharges from the screw conveyor 20 into an inlet passageway 23, preferably tapered outwardly, in the feed portion 12 of the hydrolyzing apparatus. At this time the fibrous material has taken on the form of a pressure-impervious plug 24, substantially free of air, with much of the liquid thereof squeezed out and collected from the bottom of the bin through a liquid discharge 25.
Hydrolysis occurs more quickly on small particles than on large particles, and there is provided a fluffer and mixer or shredder assembly 28 effective to break the plug 24 up into small particles. To this end the fluffer and mixer assembly 28 contains a plurality of rotatable blades 29 driven in close proximity to the inner wall of the fluffer shell by a suitable drive motor 30 and belt drive 32. Since the plug 24 defines a pressure seal in the feed portion 12, the fluffer and mixer assembly may be maintained under suitable pressure and temperature to begin the hydrolysis process. To this end a metered amount of reaction material such as steam may be introduced into the inner cavity of the fluffer and mixer assembly through a suitable steam injection inlet 32. Additionally any liquids to undergo the hydrolyzing process, such as those liquids obtained from the liquid discharge 25 at the bottom of the bin 18, may be metered into the pressurized fluffer chamber through a liquid inlet 34 in the fluffer assembly 28 in the suitable proportions to provide a desired and controllable moisture content.
The blades 29 of the fluffer and mixing assembly 28 may comprise angularly and axially spaced eccentrics each having an outer arcuate surface 29a rotatable in close proximity to the inner surface of the fluffer shell. Each blade 29 additionally has concave sidewalls 29b to provide cutting edges 29c. A pair of shields 29d, FIG. 5, outward of the blades 29 protects the packing section 37 of the fluffer and mixing assembly from solid particles of the fibrous material.
The fluffed or shredded material drops by gravity through a discharge opening 38, FIG. 4, in the bottom of the fluffer and mixer assembly 28 into the inlet end of the hydrolyzer chamber 16 through a material inlet 46. The hydrolyzer chamber 16 is, of course, a pressure device wherein the liquid and fibrous material is subjected to the hydrolyzing action of heat and steam. It has been found that a wet steam at a pressure of about 100 pounds per square inch gage, introduced into the fluffer and mixer assembly, or, if desired through suitable steam inlets 47 in the hydrolyzer chamber 16, will be effective to treat poultry materials in approximately 6 minutes. The hydrolyzer chamber 16 is provided with suitable blades or agitators 49 for agitating the material therein to obtain the most rapid hydrolyzing thereof, and additionally, the blades 49 are canted to provide a forward thrust to impel the materials along through the tube of the chamber. The blades 49 are mounted to a rotary shaft 50 driven by a variable speed motor 51 through a belt drive 52. Regulation of the retention time therefore may readily be accomplished through the combined control of the discharge means, as well as by the variation of the speed of rotation of the blades 49. If desired, a steam jacket 48 may surround the chamber 16 to conserve or add heat as desired.
At the completion of the hydrolyzing process, the treated material is discharged from the hydrolyzing chamber at a metered rate to further control the rate of flow of the material through the hydrolyzing chamber. The material must also be reduced in pressure to atmospheric, vapor must be removed, and the material must be dried for use. To this end a discharge 62 pressure feeds into the inlet of a discharge pump 65 driven by a variable speed motor 66. The pump 65 serves as a metering device to regulate the rate of discharge from the hydrolyzing chamber 16. The pump may be regulated to discharge at a desired pressure lower than the feed pressure thereto from the hydrolyzing chamber. The pump 65 discharges through a suitable conduit 67. Because the critical temperature of the material has been substantially lowered due to the lowering of the pressure acting thereon, some, if not all, of the water mixed with the product will be vaporized. The material may then be passed through a vapor separator 68 if desired which may be of the centrifugal type. The vapor is bled off through a vapor outlet 70 and may be passed into a suitable condenser 71. The condenser 71, of course, may establish a sufficient vacuum so that the vapor separator 68 discharges to below atmospheric pressure thus causing a larger conversion of the wet steam of water into vapor. The condenser 71 illustrated in FIG. 1 is of the barometric condensing type which herein cooling water is supplied to a water inlet 72 and the condensed vapor and water combined discharge through a condensate tube 73. The liquid material, or the solids in liquid suspension, passes from the vapor separator 68 through a discharge conduit 74 and into a dryer 75 where sufficient additional moisture may be driven from the treated material to provide the desired moisture content.
If desired the material discharged from the dryer may be passed through a screen 80 to separate out the fines where they will fall into a bin 81. The material which does not pass through the screen 80 may be passed through a grinder 82.
From the above detailed description of the hydrolyzing apparatus, the improved method is believed clear. However, briefly, it is understood that the improved method relates to the continuous hydrolyzing under pressure of a fibrous material in a pressure vessel defining a hydrolyzing chamber. In accordance with the present invention the fibrous material is first compacted in the inlet passage to provide a pressure-impervious seal which advantageously may be in the form of a plug. Air may be removed from the fibrous material in its formation of the pressure seal, and additionally liquids may be extracted from the material. If desired the liquids may be reintroduced into the pressure system downstream of the seal. After formation of the seal, the plug is removed downstream where it is continuously broken and shredded to pass as shredded material into the hydrolizing chamber. After the hydrolyzing is completed by the addition of water or other catalyst under high pressure and temperature, the treated material is removed from the hydrolyzing chamber through a pressure seal.
Advantageously the method and apparatus according to the present invention provides improved hydrolyzing of fibrous material such as slaughterhouse wastes or byproducts in a continuous pressure process with a minimum loss of pressure in the pressurized hydrolyzing chamber. The hydrolyzing may take place at a temperature in excess of 70 pounds per square inch gage. Since it has been found that the hydrolyzing of fibrous products intended for use as animal meal produces improved quality and quantity of digestible proteins and other ingredients above the pressure and temperature of wet steam at about 70 pounds per square inch gage, the apparatus according to the present invention produces a superior product compared to that generally available commercially. The low cost and rapid processing of the material permits economical operation of the hydrolyzing apparatus so as to dispose of the slaughter house byproducts in the most advantageous and economical manner.
Although the present invention has been described by way of a single embodiment thereof, it will be understood that numerous other embodiments and modifications may be made which come within the spirit and scope of the present invention. For example, the hydrolyzing apparatus may be used for the treatment of materials other than slaughterhouse wastes, although the above description has been made with reference to byproducts of poultry slaughterhouses. Moreover the discharge from the hydrolyzing chamber may be in any manner which will bring the material to atmospheric pressure, vaporizing to the extent possible the water contained in the treated product, and drying the treated product to the desired moisture content. To this end the pump 65 may be eliminated and throttling and metering of the material take place at the expansion valve 68.