MXPA99007754A - Drying and processing of raw food material - Google Patents

Abstract

A combined spray and rotary drying apparatus (10) includes a spray dryer (12) having a housing defining a spray drying chamber (28), an annular inlet and an outlet (50). A burner (30) and atomizer sprayer (32) are provided in the spray drying chamber (28). The outlet (50) of the spray drying chamber (28) feeds into a rotary drying drum (54). A raw material feed chute (56) is also provided for feeding raw material of relatively low moisture content directly to the rotary dryer. Methods of drying a raw material and of processing raw animal parts are also disclosed.

Description

DRYING AND PROCESSING OF RAW MATERIALS TECHNICAL FIELD The present invention finally relates to the field of processing of nutritional supplements and, more particularly to a method for processing parts of raw animals, a method for drying food raw material while retains its nutritional content and an apparatus to dry this food raw material by spraying. BACKGROUND OF THE INVENTION Food additives are substances that can be added to food during processing in order to improve desirable chemical or physical characteristics and the quality of food. One of the most important forms of food additives are nutritional supplements. These typically comprise minerals and vitamins that are added to food in order to restore the nutritional values lost during the processing of food or to supplement the natural content of food nutrients. The importance of the use of nutritional supplements to improve the health and growth of animals has been recognized for a long time in the field of animal husbandry. It has been recognized for a long time that the production of nutritional supplements from various by-products of food production operations is highly desirable. Specifically through the establishment of a commercial use for these by-products, the economic viability of the food transformation process is raised and the difficult handling of the residual material is reduced or completely avoided. It is a particularly important aspect in the case of poultry farming where significant quantities of waste materials are produced. Accordingly, several methods have been developed for the use and processing of feathers and viscera as a nutritional supplement for food products. Such processes are generally presented, for example, in U.S. Patent Nos. 3,272,632 to Speer and 4,269,865 to Retrum. One of the primary disadvantages in the prior art of processing residual products such as, for example, feathers and viscera in nutritional supplements has been the thermal degradation of several amino acids and proteins which effectively eliminates these materials as a source of nutrition. Accordingly, the need for an improved method for the processing of waste products such as feathers and viscera has been identified in order to avoid thermal degradation of important amino acids and proteins and therefore to provide a supplement with increased nutritional values. SUMMARY OF THE INVENTION Accordingly, it is a primary object of the present invention to provide an economical and efficient method for processing parts of raw animals into a supplement providing significantly improved nutritional values. Said complement can be used profitably to promote the production of blood plasma in young animals and more particularly, animals from farms such as, for example, piglets. Another object of the present invention is to provide a method for drying food raw materials such as hydrolyzed pens and viscera wherein the heat sensitive nutritional elements in these raw materials including amino acids and proteins are kept in a non-degraded and digestible state during and after the dried to a desired moisture content. Another object of the present invention is to provide an apparatus for a more efficient drying of food raw materials. Additional objects as well as advantages and other novel features of the present invention will be presented in part in the following description and in part will be apparent to those skilled in the art upon reviewing the following or may be derived from the practice of the invention. The objects and advantages of the invention will be realized and obtained through instrumentalities and combinations particularly mentioned in the appended claims. To achieve the above and other objects, and in accordance with the purposes of the present invention as described herein, an apparatus is provided for drying a raw material such as, for example, waste products including feathers and viscera processed as a food supplement. The apparatus includes a spray dryer having a frame defining a spray drying chamber and an outlet. A burner is housed in the spray dryer. In addition, means for atomizing and spraying the raw material in the apparatus are provided. In addition, a rotating drying drum is provided downstream of the spray dryer which includes an inlet in fluid communication with the outlet of the spray dryer. Accordingly, the raw material that is in the process of drying is sequentially subjected to both spray drying and rotary drying in order to bring the material to a desired moisture content. More specifically describing the invention, the frame includes an end plug opposite the outlet and spaced inner and outer walls defining an air feed passage therebetween. The air feed passage extends along the inner wall from a location adjacent to the outlet to a ring-shaped supply port adjacent to the end cap.

This provides for the preheating of the air and cooling of the inner casing before being supplied to the spray drying chamber. Preferably, the burner housed in the spray dryer is a ring burner, and the spray spray means includes a charging tube and a spray nozzle arranged concentrically in order to extend through the ring burner in the chamber of dew drying. In addition, a conical diverter is provided in the spray drying chamber. The diverter projects concentrically around the charging tube and spray nozzle. This conical diverter deflects air from the ring-shaped supply port to the outside towards the ring burner in order to provide a regular heating temperature and more consistent spray drying by removing hot parts and cold parts. In addition, the apparatus includes a source of air under pressure and a source of feedstock for supplying, respectively, air under pressure and raw material to the charging tube and spray nozzle. The loading tube includes a raw material feeding tube housed inside an air jacket for air passage under pressure. The air jacket effectively insulates the charging tube from direct heating by the ring burner and therefore ensures that the raw material does not dry inside to avoid plugging the feed tube. In accordance with another aspect of the present invention there is provided a raw material feed channel downstream of the loading tube and the spray nozzle. The feed channel is used to supply a raw material with a relatively low moisture content to the apparatus. Together, the spray dryer structure that includes the loading tube for raw material with a relatively high moisture content and the feed channel for a raw material with a relatively low moisture content work to ensure that the raw material is dried from Regularly up to a desired moisture content while simultaneously preserving the heat-sensitive nutritional elements of the raw material (amino acids and proteins) against thermal degradation that could otherwise reduce its nutritional value. Describing the invention, a means is provided for driving the rotary drying drum. In addition, the rotary drying drum includes a discharge outlet. In addition, the apparatus also includes a manifold in fluid communication with the discharge outlet of the rotary drying drum. This collector works to collect the dried raw material with a desired moisture content for further processing purposes. In accordance with another aspect of the present invention, there is provided a method for drying the raw material, and particularly, waste material such as, for example, hydrolyzed feathers and bird viscera which is being processed as particles for food supplement. The method includes both spray drying and rotary drying of the raw material having a relatively high first moisture content. In addition, the method includes the subjecting of the raw material having a relatively low second moisture content directly to the rotary drying with the raw material having the relatively high first moisture content. Thus, the material with a lower moisture content is not subject to spray drying. Accordingly, this material with a lower moisture content is not subjected to higher thermal levels that could otherwise cause the degradation of important amino acids and heat-sensitive proteins. In order to ensure that the raw material is processed and dried efficiently, the raw material is sprayed with air under pressure supplied at 60-65 and, more preferably, 75-80 psi. In addition, an air stream velocity in the rotary drying drum of substantially 450-550 feet per minute is maintained. Finally, in accordance with another aspect of the present invention, a method for processing raw animal parts is provided. This method includes spraying the raw animal parts to a size smaller than 0.25 inches. After that the heating of the raw animal parts is carried out to provide a partial rupture and the centrifugation of the raw animal parts in order to separate the partially processed animal parts in a particle phase, a phase of water and an oil phase. The water phase is then subjected to spray drying and the particles and the spray dried water phase are subjected to a rotary drying in order to recover any additional portion of food in the water phase and to remove the water by evaporation . This effectively eliminates the need to provide separate wastewater processing and, of course, is an approach that respects the environment. Finally, the method includes the collection of the particles with a desired moisture content for further processing. Other objects of the present invention will be apparent to those skilled in the art from the following description where a preferred embodiment of this invention is shown and described, simply as an illustration of a preferred embodiment for carrying out the invention. As will be appreciated, the invention can be applied in other embodiments and its various details may have modifications in several obvious aspects without departing from the invention. Accordingly, the drawings and descriptions will be considered as illustrative and not restrictive in nature. BRIEF DESCRIPTION OF THE DRAWING The annexed drawing incorporated and forming part of the specification illustrates several aspects of the present invention and together with the description serves to explain the principles of the invention. In the drawing: Figure 1 is a partially sectioned, partially schematic view of the apparatus of the present invention for the combined dew and rotary drying of the raw material; Figure 2 is a detailed cross-sectional view of the spray dryer section of the drying apparatus illustrated in Figure 1; Figure 2 / (a) is a detailed cross-sectional view along line 2 (a) 2 (a) of Figure 2 showing the spray dryer section; Figure 3 is a cross-sectional view of the rotating drying drum section of the apparatus illustrated in Figure 1; Figure 4 is a cross-sectional view of the primary solids or particle collector section of the drying apparatus of Figure 1; Figure 5 is a detailed view showing the sealing detail of the spray dryer section and the rotary drying drum section; Fig. 6 is a detailed cross-sectional view showing the detailed seal between the rotary drying drum section and the particle collector section; and Figure 7 is a schematic block diagram showing the method of the present invention for processing raw animal parts. Reference will now be made in detail to the currently preferred embodiment of the invention, an example of which is illustrated in the accompanying drawing. DETAILED DESCRIPTION OF THE INVENTION Reference is now made to Figures 1-6 which show apparatus 10 of the present invention for drying raw material such as for example a nutrient supplement formed from hydrolysed feathers, whole blood and bird viscera. As generally shown in Figure 1, the apparatus 10 includes a spray dryer section 12, a rotary dryer section 14 and a solid collector / primary particle collector section 16. More specifically, the spray dryer section 12 includes a frame that includes an outer cylindrical wall 18 and an internal cylindrical wall 20. As shown, the internal cylindrical wall 20 is concentrically positioned and extends into the outer cylindrical wall. 18 in such a way that between them a ring-shaped air supply passage 22 is defined. This air feed passage 22 extends along the inner wall 20 to a ring-shaped supply port 24 adjacent an end cap 26 that closes one end of the outer wall 18. Together, the outer wall 18 , the inner wall 20 and the end plug 26 define a spray drying chamber 28 where the air is fed through the ring-shaped supply port 24. As shown further in Figure 1 and with reference to In a more detailed manner in Fig. 2 and 2 (a), a ring burner 30 is housed in the spray drying chamber 28 so that it is concentrically positioned in relation to the inner wall 20. In addition, a raw material atomization sprayer , generally designated with the reference numeral 32 is mounted for a relative sliding movement in the end pad 26. The atomizing sprayer 32 includes a charging tube 24 having air under pressure and mains power inlets. eria 36.38 at its proximal end and a spray nozzle 40 at its distal end. As shown, the loading tube 34 is concentrically positioned in such a manner that it extends into the ring burner 3-0 in the spray drying chamber 28. As further shown with reference also to Figure 7, the pressurized air inlet 36 is connected to a source of pressurized air 42 that provides or supplies air at a pressure of substantially 60-85 and more preferably 75-80 psig. Similarly, raw material input 38 is connected to a raw material feed source such as a storage tank 44 containing the raw material to be processed. Specifically, the raw material from the storage tank 44 is received at the inlet 38 and passes through a feed tube 467 to the nozzle 40. The air under pressure from the source of air under pressure 42 is received at the inlet of air under pressure 36 and travels through the charging tube 34 which functions as an air jacket around the feeding tube 46 (see also figure 2 (a)) thus protecting the raw material in the feed tube against temperatures raised in the dryer produced by the ring burner 30. Therefore,, no drying of the raw material occurs in the feeding tube 46 and the free flow of the raw material in this tube is ensured. In addition, the air in the charging tube / jacket 34 is preheated in such a way that no moisture is added to the raw material that is in the drying process. Since the atomization sprayer 32 can be displaced by sliding in and out of the end cap 26, it will be seen that the distance over which nozzle 40 is projected in the spray drying chamber 28 can be adjusted. Thus, a faster drying can be offered by positioning the nozzle, for example, at point A (see figure 2). In this position, the raw material is sprayed from the nozzle adjacent the ring burner 30 where it is subjected to higher drying temperatures. Alternatively, the nozzle 40 can be positioned, for example, at point B (see again figure 2). In this position the raw material is sprayed from the nozzle 40 further downstream in relation to the ring burner 30. Thus, there is less direct application of heat and the raw material is subjected to lower drying temperatures. The position of the nozzle 40 in relation to the burner ring 30 can be adjusted to meet the needs of the particular application. As shown also in Figures 1 and 2, a conical diverter 48 is carried which projects concentrically around the loading tube 34. This conical diverter 48 serves to deflect the air coming from the ring-shaped supply port 24 outwards. towards the ring burner 30. This advantageously ensures a regular heating of the air thus increasing the performance of the dryer by substantially eliminating hot spots or cold spots that may otherwise cause inconsistent drying of the product. As further shown in Figures 1 and 2, the inner wall 20 of the spray dryer section 12 defines an outlet 50. This outlet 50 communicates directly with the drying chamber 52 defined by the rotating drum 54 of the drying section. rotary 14. Further, a raw material feed channel 56 is provided in the inner wall 20 of the spray dryer section 12 downstream of the loading tube 34 and spray nozzle 40. It will be noted that the raw material containing moisture Relatively smaller is supplied through this feed channel 56 in such a way that it is not directly subjected to the heat coming from the ring burner 30. This works to protect the temperature sensitive elements including amino acids and raw material proteins in this material with a lower moisture content against degradation that would negatively affect the nutritional value of the food product in a negative way. Count The seal between the spray dryer section 12 and the rotary dryer section 14 is best illustrated in FIG. 5. Specifically, the stationary internal wall 20 of the spray dryer section frame 12 includes a seal flange 58 substantially in place. U-shape that projects towards the outside. The rotary drum 52 of the rotary drying section 14 includes a flange 60 substantially in an inwardly extending n shape that engages freely with the flange 58 substantially in the form of a corresponding u in the inner wall 20. Seals the flange 58 substantially U-shaped and substantially n-shaped flange 60 provide a baffle type seal that minimizes air flow losses as air travels from the dew section 12 to the rotary drying section 14. The rotating drying section 14 has a design generally well known in the art. Specifically, the rotating drum 54 includes a thermally insulating shield 55 incorporating at least two tire assemblies 62. Each rim assembly 62 includes a rim 64 mounted by means of wedges 68 on a band 66 fixed on the drum 54. Each tire assembly is moved in a die assembly generally designated by the reference numeral 70. Each die assembly 70 extends along an arc of substantially 60-90 ° and includes a set of two trunnion rollers 72 that receive a rim 64 and serve to support the weight of the rotating drum 54. Thrust rollers 73 maintain the rims 64 in alignment with the trunnion rollers 72. It is provided an engine 74 for driving the rotary drum 54 through a chain 75 that engages a sectioned gear 76 mounted on the drum. In figure 3, the rotary drying drum 54 includes a series of optional plates 78 supported by mounting brackets 79 such that they are positioned concentrically within the center of the drum 54. These operate to deflect the air flowing through the rotating drum 54 and, consequently, the raw material dried and transported by this air to the side wall of the dryer drum. This works to increase the drying action in a manner known in the art. The outlet 82 of the drying drum is connected in a fluid communication with the inlet 83 to the frame 84 defining the primary solids / particle collector 16. The seal formed between the rotating drum 54 and the collector frame 84 is best shown with details in Figure 6. As shown the rotating drum 54 includes a flange 86 projecting outwardly and the collection frame 84 includes a substantially T-shaped flange 88 projecting outwards. A boiler rope packing 90 is provided in segment 92 of the T-shaped flange 88 as shown in Figure 6. This arrangement protects against contamination with colder air and ensures the best possible dryer efficiency. The solid / primary particle collector 16 also includes a pair of discharge screws 94, 96. The first discharge screw is longitudinally aligned with the rotary drum 54 of the rotary drying section 14. This discharge screw 94 is driven by a motor 98 and feeds dry raw material to the second partially underlying discharge screw 96. The second discharge screw 96 is driven by a motor (not shown) and supplies the dried raw material to a discharge channel (not shown) for further processing. An upper discharge duct 99 directs the air stream from the solids / particle collector 16 to a cyclone 114 in accordance with a further description of the processing method presented below (see also figure 7). The use of the drying apparatus 10 of the present invention will now be described in detail in relation to a raw material drying method and a method of processing raw animal parts. In accordance with the methods and as illustrated in Figure 7, a poultry viscera raw material is fed from a container 100 and supplied to a sprayer device 102 where it is sprayed to the desired size and consistency (e.g. , no piece larger than inches in diameter). After spraying, the raw material is fed from the sprayer 102 to a heating unit 104. There the product is heated to a temperature comprised between 195 and 205 ° F in order to partially break up the particulate raw material, a phase of water and an oil phase. These three phases are then supplied to a three step centrifuge 106 where the oil is separated and supplied to an oil storage vessel 108. Simultaneously, the water phase is supplied to a spray water storage tank 44. From there, the water phase is supplied by means of a pump 110 to the raw material inlet 38 of the charging tube 34. Compressed air is supplied from the source 42 to the air inlet under pressure 36 of the same charging tube 34 and air and raw material are sprayed together through the nozzle 40 in a whole cone spray pattern in the spray drying chamber 28 of the spray dryer section 12. The burner ring 30 incorporates inwardly directed jets of gas directing the flames toward the nozzle 40. As a result of the spray pattern and inwardly directed jets, the raw material is quickly dried in order to prevent it from Adheres on the walls of the appliance during the drying process. Simultaneously, particles from the three-step centrifuge 106 are supplied to the feed channel 56 for delivery in the rotary dryer 14 of the drying apparatus 10 in accordance with what is described in more detail above. As a result of this arrangement, it will be noted that the water phase is subjected to spray drying in the spray dryer section 12 and then rotary drying in the rotary drying section 14 while the particles are subjected only to rotary drying in the rotary drying section. Thus, the water phase of higher moisture content is subjected to higher temperatures and greater drying to remove the water through evaporation and recovery of additional raw material from the particles. Simultaneously, particles with a relatively low moisture content are subjected to lower temperatures and less drying. Therefore, the amino acids, proteins and other nutrition sources contained therein and sensitive to temperature are protected against thermal degradation. The processed particles are then recovered in the collection section of solids / primary particles 16. In order to ensure proper operation of the drying apparatus, the air under pressure from the source of air under pressure 42 is supplied to substantially 60- 85 psig, and more preferably 75-80 psig. Simultaneously, an induced current fan 112 is provided downstream to ensure that an air stream velocity of substantially 450-550 feet per minute is maintained in the rotary drying drum 54. It is this air stream that carries the dried raw material or particles through the rotary drying drum 54 to the primary solids collector 16. A cyclone 114 and a scrubber 116 clean the air before it leaves the environment. The particles recovered in the primary solids collector 16 and cyclone 114 are then supplied to a mill 118.

From the mill 118, the particles are subjected to calibration through a screen 120 and then supplied to a storage container 122 to await further processing or shipping. After processing, the particles have a moisture content of preferably between 5 and 8%. The above description of a preferred embodiment of the invention has been presented for purposes of illustration and description. It has no purpose to be complete or to limit the invention to the precise form shown. Modifications or obvious variations are possible taking into account the previous teachings. This embodiment was chosen and described to provide the best illustration of the principles of the invention and its practical application to enable a person with certain knowledge in the art to use the invention in various modalities and with various modifications suitable for the particular use contemplated. All these modifications and variations are within the scope of the present invention as determined by the appended claims when they are interpreted in accordance with the scope that corresponds to them, fairly, legally and equitably.

Claims (15)

1. CLAIMS 1. An apparatus (10) for drying a raw material, said apparatus comprising: a spray dryer (12) including a frame defining a spray drying chamber (28) and an outlet (50); a burner (30) housed in said spray dryer (12); and means (32) for atomizing and spraying said raw material in said apparatus; said apparatus is characterized in that it has: a rotating drying drum (54) downstream of said spray dryer (12) and includes an inlet in fluid communication with said outlet (50) of said spray dryer. The apparatus (10) according to claim 1, wherein said frame includes an end cap (26) opposite said outlet (50) and internal and external spaced walls (18, 20) defining a feed passage of air (22) between them. The apparatus (10) according to claim 2, wherein said air feed passage (22) extends along said inner wall (20) from a location adjacent to said outlet (50) towards a ring-shaped supply port (24) adjacent said end cap (26) that provides cooling of said spray dryer frame and preheating said air prior to delivery to said spray drying chamber (28) . The apparatus (10) according to claim 1, or 3, wherein said burner (30) is a ring burner and said atomizing and spraying device (32) includes a loading tube (34) and a spray nozzle (40) arranged concentrically to extend through said ring burner in said spray drying chamber (28). The apparatus (10) according to claim 4, further including a conical reflector (48) projecting concentrically around said loading tube (34) and contains spray (40) to divert air from said ring supply port (24) outwardly towards said ring burner (30) to provide regular heating. The apparatus (10) according to claim 5, further including a source of air under pressure (42) and a source of feedstock (44) to supply, respectively, air under pressure and raw material to said tube. charge (34) and spray nozzle (40). The apparatus (10) according to claim 6, wherein said loading tube (34) includes a raw material feeding tube (46) housed inside an air jacket for the passage of said air under pressure to said air nozzle. dew (40). The apparatus (10) according to claim 1, further including a raw material feed channel (56) downstream of said loading tube (34) and spray nozzle (40) to supply a raw material with a content of relatively lower humidity to said apparatus. The apparatus (10) according to claim 8, wherein said feed channel (56) is carried by said internal wall (20) of said frame and extends in said rotating drying drum (54). The apparatus (10) according to claim 1, further including a device (74) for driving said rotating drying drum (54). The apparatus (10) according to claim 10, wherein said rotating drying drum (54) includes a discharge outlet (82) and said apparatus further comprises a collector (16) in fluid communication with said discharge outlet of said drum. rotary drying. A method for drying a raw material, comprising: a spray drying of said raw material having a relatively high first moisture content; said method is characterized in that it has: a rotary drying of said raw material having a first relatively high moisture content immediately after the spray drying and the subjecting of the raw material having a relatively low second moisture content directly to a rotary drying with said raw material having a relatively high first moisture content. The method according to claim 12, which includes spraying with air under pressure supplied at 60-80 psig. The method according to claim 13, which includes maintaining an air stream velocity in said rotary dryer drum of 450 to 550 feet / minute. 15. A method of processing raw animal parts, comprising: spraying said parts of raw animal; heating said raw animal parts; centrifuging said raw animal parts to separate said particulate animal parts, a water phase and an oil phase; and subjecting said water phase to spray drying; said method is characterized in that it has the following: to subject said particles and said water phase subjected to spray drying to a rotary drying; and collecting said particles with a desired moisture content for further processing.