JP3840655B2 - Method and apparatus for converting food waste into food material or feed - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method and an apparatus for converting food waste such as food processing residue into a food material or feed.
[0002]
[Prior art]
Conventionally, food processing residue, cooking residue, mixed residue etc. from food distribution processes such as school / hospital school facilities, hotel accommodations, large-scale retail stores, restaurants / caterers, food manufacturing factories, sales stores, etc. Some of these food wastes are directly used as feed for pig farming and compost production, but most of them are incinerated or landfilled as waste.
Also, in recent years, in the field of livestock, it has been changed to a planned breeding method for producing high-quality meat, and its use as feed is limited to high-temperature dry high protein powder added to imported grains and the like.
[0003]
Food waste generally has a high moisture content of about 65 to 90%, so it easily perishes, contains a lot of foreign matters, is generated in many items, is dispersed in a small amount, and is difficult to handle. In cities and the like, collection is requested from specialists for a fee, and most of the collected items are mainly incinerated as raw garbage without being recycled as described above. In addition, it has been pointed out that the temperature in the incinerator does not rise due to the high water content even during incineration, and salt content in the waste causes dioxins.
[0004]
Under these circumstances, food waste is slightly dried at a high temperature of 150 ° C. or more and is being sought to be used for feeds. However, in high temperature drying, the temperature difference between the drum temperature and the product temperature remains large. As the drying progresses, uniform drying is difficult, and there are many cases where a portion of the burned, burnt, overdried or undried state is mixed, and it is difficult to obtain a high quality feed. In addition, the high-temperature drying increases the equipment cost, the drying energy cost, and the equipment cost for removing odor due to scorching and the energy cost for odor combustion.
[0005]
[Problems to be solved by the invention]
The present invention is dried while maintaining the characteristics of food processing residues and other materials constituting food waste, and is used for food materials or high value-added feed materials such as livestock, fish and pets. It intends to contribute to an advanced recycling society and environmental conservation.
[0006]
[Means for Solving the Problems]
The present invention allows food waste to be dried at a relatively low temperature of 100 ° C. or lower, preferably 90 ° C. or lower, more preferably 80 ° C. or lower to obtain a dried product, and retains the characteristics of the material without scorching the food. And recycle effectively.
In this drying, food waste is put into a rotary drum body, hot air of 100 ° C. or less is supplied, and the waste is dried while being cut off by a blade provided in the drum body, and then granulated or granulated. To obtain a dried product.
Since such drying is performed with hot air of 100 ° C. or less, exhaust heat generated from a boiler, a refrigerator, a private power generation device, or the like can be effectively used.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
The drum body 1 of the rotary drum dryer 11 used for drying is placed horizontally, and can be rotated in both forward and reverse directions by using a rail 49 provided on the drum body 1 by a roller-3 on the frame 2 as a guide. And is rotated by the motor 4 so that the speed can be changed. The illustrated drum body 1 has an octagonal cylindrical shape by attaching a side plate 6 to a frame bar 5, but may be a hexagonal shape or other polygonal shapes. (FIGS. 2, 3, 4, and 5)
At the center of one end plate 7 of the drum body 1, there is provided an inlet 8 for feeding food waste to be dried into the drum body 1, and in the illustrated case, a hopper 9 to a screw conveyor. 10 can be put into the drum body 1.
[0008]
Around the screw conveyor 10 of the end plate of the drum main body 1, an air blowing port 12 for drying air is provided, and hot air for drying supplied through a flexible duct 13 is supplied into the drum main body 1. Like to do.
Inside the end plate 7 of the drum body 1, a space 14 is placed from the inner surface of the end plate 7, and an umbrella-shaped baffle plate 15 is erected. A donut-shaped baffle plate 17 is erected at an interval 16 from the end plate 7. (Fig. 2, Fig. 3, Fig. 6)
[0009]
The end plate 20 on the side opposite to the air blowing port 12 protrudes outward, and an exhaust port 21 is provided at the center thereof, and is connected to a cyclone 23 from a flexible exhaust duct 22 as necessary. The working air is exhausted. Inside the end plate 20, an umbrella-shaped baffle plate 24 having the same shape as the umbrella-shaped baffle plate 15 provided on the end plate 6 on the air supply port 12 side is provided. A trumpet baffle 25 is provided. (Fig. 2, Fig. 3, Fig. 7)
Drying progresses and the dried product that rises with the warm air hits the baffle plate 24 and is prevented from coming out of the drum body 1 from the exhaust port 21. The donut-shaped baffle plate 17 and the trumpet-shaped baffle plate 25 act so that the contents being dried in the drum body do not come out of the drum.
[0010]
The drying air sent from the air blowing port 12 strikes the umbrella-shaped baffle plate 15 on the input side and is sent toward the side plate 6 of the drum body 1, and a part of the air is blown out like a donut. The air hits the plate 17 and is also supplied to the middle part of the drum body.
[0011]
In the drum main body 1, a blade for stirring the charged food waste is provided. In the illustrated example, the cutting blade 26 is attached to every other one of the eight frame bars 5 toward the center of the drum. Ten cutting blades 26 are provided on a single blade bar 27 at equal intervals in the longitudinal direction. Four of the nine long straight blades 28 of the cutting blade 26 have a narrow plate shape, and a flat surface 29 thereof extends along the rotation direction of the drum body 1. Further, one blade 26 on the air outlet 12 side is a short straight blade 48.
The other five blades among the nine long blades 26 are twist blades 30 twisted at an angle of about 30 ° to the right at substantially the middle portion thereof. The blade bar 27 having the twist blade 30 twisted on the right side is attached to a pair of opposed frame bars 5. (FIGS. 2, 3, 8, and 10)
[0012]
The cutting blades 26 provided on the blade bar 27 attached to the other pair of opposed frame bars 5 are the five blades that are arranged in the same manner as the above among the nine long blades 26. However, the twist blade 31 is twisted at an angle of about 30 ° on the left side at the substantially middle portion thereof, contrary to the above. (FIGS. 8 and 12)
[0013]
In the frame bar 5 between the frame bars 5 and 5 provided with the cutting blade 26, a rectangular lifter blade 32 having a thin triangular shape as viewed from the longitudinal direction of the drum is provided on the blade bar 33. And four blade bars 33 are attached to the frame bar 5 at equal intervals. A frame bar provided with four same lifter blades 32 is also attached to the frame bar opposed to the frame bar. (FIGS. 2, 3, 8, and 11)
[0014]
The other opposed frame bar 5 is provided with four lifter blades 32 on the above-described blade bar 33, corresponding to the portion 34 without the lifter blades. A blade bar 35 provided with three lifter blades out of phase is attached to the frame bar 5 so that the lifter blade is positioned. As a result, the contents in the drum main body are uniformly scraped. (Fig. 12)
[0015]
Thus, the cutting blades 26 and the lifter blades 32 are alternately arranged for the eight frame bars 5. (FIGS. 8 and 12)
The blades 27, 33 and 35 are detachably provided on the frame bar 5, and can be conveniently replaced with other types of blades depending on the contents to be washed or dried.
[0016]
FIG. 13 shows another type of cutting blade 26, which is connected by two cylinders 47 arranged at intervals between two parallel straight blades 46. The two cylinders 47 disposed between the two straight blades 46 adjacent to each other are provided with different phases from those described above, thereby enabling uniform cutting. Is.
[0017]
The end plate 20 on the exhaust port 21 side is provided with an openable / closable discharge port 36, and dried matter can be taken out from the discharge port 36 by a discharge chute 37. (FIGS. 2, 4, 7, and 9)
If the side plate 6 attached to the frame bar forming the drum body 1 is made removable, it is convenient for cleaning or the like.
In addition, since the dryer such as the drum body can be easily assembled and disassembled, it can be easily transported to the necessary food processing factories, feeding centers, and other processing plants, and food waste is generated. In the place, an effective dispersion process according to the waste can be performed, and it can be widely used.
[0018]
The gantry 2 that supports the drum body 1 is configured such that the exhaust side is supported by a shaft 38 and the air supply side can be moved up and down by a hydraulic lift 39 or the like, and the drum body 1 is slightly moved so that the exhaust side is lowered. If the drum body is tilted and rotated, it becomes easier to take out the dried material from the discharge port 36. (Figure 2)
[0019]
The side plate 6 of the drum main body 1 is provided with a slide-type hatch 42, and the drum main body 1 can be stopped and the material can be directly fed into the drum main body 1 without using the screw conveyor 10. it can. If the outside of the drum body 1 is covered with a box 43 formed of a heat retaining material, the drum body 1 can be prevented from being cooled during drying, and the thermal efficiency of drying can be increased. (Fig. 1, Fig. 2, Fig. 4)
[0020]
When food waste is put into the drum body 1 and the drum body 1 is rotated, the food waste is lifted by the lifter blade 32 and then falls downward, and the straight blade 28 and the twist of the cutting blade 26 are twisted. The blades 30 and 31 act to cut food waste straightly or diagonally, and the food waste is shredded while the air for drying hits it without causing the contents to knead. Can be dried.
[0021]
When the drum body 1 is rotated at a high speed especially in the early stage where the food waste has a lot of moisture, and the food waste is finely cut and loosened, the drying can be efficiently advanced. Since it becomes granular, it is recommended to slow down the rotation. In the initial stage of drying, the temperature of the warm air is set to a high value of about 100 ° C., for example. If the drying proceeds to some extent and then the temperature of the warm air is lowered to about 90 ° C. or about 80 ° C., the drying time is shortened. And be efficient.
The warm air sent from the blower port 12 to the drum body 1 is exhausted by the exhaust duct 22 from the exhaust port 21 at the center of the end plate 20 on the opposite side, and traps particles through the cyclone 23 as necessary. It is good to collect. Moreover, even if there is an odor, it can be easily removed with a water scrubber. (Figure 2)
[0022]
【Example】
(Example 1)
Non-standard cooking processing residue discharged from the croquette manufacturing process of a frozen food factory is processed.
In this processing residue, cracks occurred during the molding process, clothes were unevenly attached, burned when fried in oil, cracks occurred after fried in oil Etc. are included at room temperature.
70 kg of the croquette residue was put into a drum main body 1 having a length of about 130 cm and an inner space of about 0.7 m ^{3 in} an octagonal shape with a distance of 86 cm between the opposing frame bars 5. The drum body 1 may be charged into a batch system from the hatch 42 provided on the side plate 6 at once, or may be gradually charged by the screw conveyor 10 while rotating the drum body 1.
[0023]
Dry air is supplied from the dry air generator through the duct 13 into the drum body from the air outlet 12 at a speed of 0.5 to 1 m / sec. The temperature of the dry air at the air blowing port is 80 ° C. Since this temperature is relatively low, using unused energy such as waste heat from boilers in food processing plants, waste heat from refrigerators, and waste heat from private power generation equipment, equipment costs and running costs Can be dried economically.
[0024]
The warm air that has entered the drum body from the air blowing port 12 strikes the umbrella-shaped baffle plate 15, and a part of the warm air flows to the donut-shaped baffle plate 17 and flows so as to spread widely along the side plate 6 of the drum. Since the exhaust air is exhausted from the exhaust port 21 by hitting the umbrella-shaped baffle plate 24 provided on the end plate 20 on the exhaust side, the warm air flows uniformly in the drum.
[0025]
The dry matter carried by the hot air discharged from the exhaust port 21 of the drum end plate 20 is collected by the cyclone 23, and the exhausted hot air may be circulated and reused as necessary. The recirculation utilization rate of the exhaust hot air is efficient when determined by the drying progress state of the object to be dried, the absolute humidity and the relative humidity of the exhaust hot air.
[0026]
Due to the rotation of the drum body 1, the contents do not slide on the side plate 6, and the contents are lifted up and dropped by the lifter blade 32, so that contact with hot air is increased and drying efficiency is improved. Can be raised. Further, the cutting blade 26 makes the contents straight, diagonally to the right, and diagonally to the left while being dried in close contact with the warm air, and the increase in viscosity is suppressed. There is nothing.
[0027]
When the above hot air was supplied into the drum body and the drying proceeded to keep the temperature inside the drum at 80 ° C, the product temperature (the temperature of the contents) and the internal temperature (the temperature inside the drum body) changed. Was as shown in FIG.
At this time, the temperature inside the drum body is 5 minutes by a thermo-hygrometer (Neuro-Higrometer HN-CGA, manufactured by Chino Co., Ltd.) equipped with a platinum resistance thermometer thermometer and a polymer capacitive hygrometer. Each time, it was measured continuously. In addition, the product temperature in the drum body uses a non-contact thermometer (THERMO-HUNTER BUILT-IN2, manufactured by Optec Co., Ltd.) to absorb far infrared rays emitted from the contents to be dried. The amount of energy was converted into a temperature value and measured in real time in a non-contact manner. Also, as a means of reconfirmation, a temperature logger (TEMPERATURE LOGGER 3650, manufactured by Hiki Co., Ltd.) with a button size is put into the contents for the product temperature in the drum body. The temperature change over time was confirmed.
[0028]
As shown in FIG. 14, the temperature in the drum has been maintained at 80 ° C. after about 1 hour, and the product temperature has been maintained at about 40 ° C. for a long time from 2 hours to 6 hours. The product temperature gradually approached the drum internal temperature, and after about 9 hours, the drum internal temperature and the product temperature reached 80 ° C. And the water | moisture content of the dried material at that time is about 8%, and drying is completed.
Accordingly, it is understood that if the temperature inside the drum and the product temperature are monitored in real time and the drying is finished when the two coincide, the optimum drying can be performed without insufficient drying or excessive drying.
[0029]
At the end of the drying, the dried product was in the form of granules having a diameter of about 1 to 2 mm, and no irregular lumps were observed. Therefore, pulverization and sieving after drying were not particularly required. And the burnt odor was not felt in the dried product.
Moreover, the situation of the rate of decrease in moisture during drying decreases linearly as shown in FIG. 15, and it can be seen that good drying is performed. This is because the contents are sheared apart by the straight blade 28 and the twist blades 30 and 31 of the cutting blade 26 especially in the initial stage of drying, and the contact area with the dry air is kept large, and the contents are prevented from agglomerating. This is thought to be because uniform and effective drying is performed throughout.
[0030]
Furthermore, when looking at the transition of dry matter weight (content weight), 70kg input was dried and decreased to about 21kg (Fig. 16), moisture decrease (Fig. 17), moisture content transition (FIG. 18), the relationship between the drying speed and the moisture content (FIG. 19) shows that constant rate drying continues from the initial stage of drying to the middle stage, and that the drying method and apparatus can maintain a good dry state. I understand.
[0031]
Since cooking residues can be dried at such a low temperature, high equipment costs and high running costs are not required as in conventional high-temperature drying. Also, since it is difficult to confirm the end of drying in high-temperature drying, the operation management of drying is complicated, but without this, if drying is finished when the internal temperature and the product temperature match as described above, A high quality dry product can be obtained easily and at low cost.
[0032]
The dried croquette residue thus obtained can be reused as a food material. It can also be widely used as feed for various livestock.
Usually, the mixing rate in the feed should be about 30% or less, preferably about 10%.
[0033]
In a growth test using chicken chicks, 30% of the dried product was mixed in the feed, and the influence of the drying temperature on the feeding efficiency (feeding efficiency) was examined. The result shown in FIG. 20 was obtained. In other words, at a drying temperature of 100 ° C. or higher, the feed efficiency is gradually lower than that of a control (grown using a general mixed corn-based feed). It can be seen that the efficiency is high and good results are obtained.
[0034]
Further, when the influence of the drying temperature on the amino acid content was examined, the results as shown in FIG. 21 were obtained. When the drying temperature is higher than 100 ° C., the lysine content is drastically reduced. However, even when drying at 80 ° C., the lysine content similar to that at 60 ° C. is maintained. It can be seen that an effective feed can be obtained without increasing useful ingredients while reducing the weight.
[0035]
(Example 2)
The cabbage cooking residue discharged from the Shizuoka City Lunch Center was processed.
The cabbage cooking residue is a peeled portion of the surface of the cabbage ball, cut debris, or the like. The drum having the structure described in Example 1 above is roughly cut into about 10 cm square, cut, blanched with hot water if necessary, and rotated little by little through the screw conveyor 10 from the hopper 9. 100 kg was put into the main body 1. At the same time, warm air at 90 ° C. was sent and dried for 6 hours in the same manner as in Example 1 to obtain about 7 kg of dried product.
This dried product has a water content of 6%, is dark green, and has a curled shape of about 1 to 3 cm in length. The dried product was a high protein product having a protein content of about 20% and could be used as a food material. It was also useful as livestock feed.
[0036]
(Example 3)
The food waste mixed with the remaining rice, bread, stir-fried beef and vegetables, french fries, vegetable salad, etc. discharged from the Shizuoka City Lunch Center was processed.
This food waste was put into the drum body 1 at a time and dried by sending hot air of 100 ° C. This food waste contains sticky leftover food, but the contents do not slide on the side plate of the drum body during drying, and do not adhere to the drum body. However, it does not become a large lump, but is well stirred by a lifter blade, cut by a cutting blade, and loosened in a dispersed state. As a result, the frequency and area of contact with warm air increased, and drying was performed efficiently. In this drying, the rotation direction of the drum body was changed at intervals of 10 minutes. One hour after the start of drying, the temperature of the hot air was lowered to 90 ° C., and drying was further continued for 5 hours. The dried product thus obtained had a water content of about 5% and was granular, and could be used as a livestock feed.
In addition, starch and meat were mixed in this food waste, but the whole was dried at the same time, and the Maillard reaction did not occur as when dried at high temperature.
[0037]
【The invention's effect】
As described above, since the present invention does not loosen food waste such as food processing residues put into the drum body, the dry air is uniformly sent to the whole, and a relatively mild temperature of 100 ° C. or less. Since the drying is performed in a state, a dry product with good quality can be obtained at low cost. Moreover, since the amount of blowing air, the rotation speed of the drum body, the conversion of the rotation direction, and the like can be easily set and drying can be performed in various patterns depending on the contents to be dried, drying can be performed efficiently. . Furthermore, mixed leftovers and the like can be similarly dried to reduce the weight for easy handling and to be used as a material for compost feed.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an embodiment of an apparatus of the present invention.
FIG. 2 is an explanatory diagram of an embodiment of the apparatus of the present invention.
FIG. 3 is an enlarged cross-sectional view of the drum body of FIG.
4 is a perspective view of the drum body of FIG. 2. FIG.
FIG. 5 is a perspective view of a support portion of the drum body.
FIG. 6 is an inner surface view of an end plate on the air outlet side of the drum body.
FIG. 7 is an inner surface view of an end plate on the exhaust port side of the drum body.
FIG. 8 is an explanatory diagram showing an arrangement state of blades in the drum main body.
FIG. 9 is an external view of an end plate on the exhaust port side of the drum body.
FIGS. 10A and 10B show a cutting blade disposed in the drum body, where FIG. 10A is a plan view and FIG. 10B is a front view.
FIG. 11 is a perspective view of a lifter blade disposed in the drum body.
FIG. 12 is an explanatory view showing an arrangement state of blades attached to eight frame bars of the drum main body.
FIGS. 13A and 13B show a modification of the cutting blade disposed in the drum body, where FIG. 13A is a plan view, FIG. 13B is a front view, and FIG. 13C is a side sectional view.
FIG. 14 is a graph showing changes in contents and temperature in the drum body during drying.
FIG. 15 is a graph showing a transition of a decrease in water content during drying.
FIG. 16 is a graph showing changes in content weight during drying.
FIG. 17 is a graph showing the transition of the amount of water decrease in the contents during drying.
FIG. 18 is a graph showing the transition of the moisture content of the contents during drying.
FIG. 19 is a graph showing the relationship between the moisture content and the drying rate during drying.
FIG. 20 is a graph showing the effect of drying temperature on feed efficiency.
FIG. 21 is a graph showing the effect of drying temperature on lysine content.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Drum main body 2 Base 3 Roller 5 Frame bar 6 Side plate 7, 20 End plate 8 Input port 10 Screw conveyor 11 Drum type dryer 12 Blower port 15, 24 Umbrella-shaped baffle plate 17 Donut-shaped baffle plate 21 Exhaust port 26 Cutting Blade 28 Straight blade 30, 31 Twist blade 32 Lifter blade 36 Discharge port 42 Side plate hatch 43 Box

Claims (7)

Horizontally mounted rotary drum body, warm air blower opening provided on the end plate of the drum body, and an umbrella shape attached to the end plate of the drum body so that the warm air is distributed along the drum body A food material or feed conversion apparatus for food waste comprising a baffle plate and a blade projecting inward of the drum body, wherein the blade is a lifter blade that scrapes the food waste as the drum body rotates, It has a narrow blade shape and has a cutting blade provided so that its flat surface follows the direction of rotation of the drum body. Food processing residues discharged from food factories, lunch centers, large-scale retail stores, etc. the residue, a mixture leftovers other food waste accommodated in said drum body, while rotating the drum body to supply 100 ° C. or less of the hot air, the food waste raised scraped by the lifter blades It said the cutting blade particulate or granulated while disentangling cut the food waste, dry food materials or feed methods of food waste and food materials or feed without scorching when falling. 2. The food material or feed method for food waste according to claim 1, wherein a part of the cutting blade of the apparatus is a twist blade twisted to the right or left at substantially the middle part thereof.   The above-mentioned hot air for drying at 100 ° C. or less is supplied from the end plate of the drum body, and the food waste is distributed along the side plate of the drum body by the baffle plate provided in the drum body and throughout the drum body. 3. The food material or feed method for food waste according to claim 1, wherein the food waste is dried by increasing contact with the food material.   The temperature in the rotary drum dryer containing the food waste is kept at a constant temperature of 90 ° C. or less, the temperature of the food waste rises with the drying, and the temperature of the food waste matches the temperature in the drum dryer. The food material or feed method for food waste according to any one of claims 1 to 3, characterized in that the time is when drying is completed. The food waste according to any one of claims 1 to 4, wherein the hot air for drying at 100 ° C or less is obtained using waste heat from facilities such as a boiler, a refrigerator, and a private power generator. Food material or feed method. Horizontal rotating drum body for receiving food waste, hot air blower opening provided in the end plate of the drum body, and end plate of the drum body so that the hot air is distributed along the drum body An umbrella-shaped baffle plate attached to the drum body and a blade projecting inward of the drum body, the blade having a lifter blade that scrapes the food waste as the drum body rotates, and a narrow plate shape. Therefore , the food material of the food waste provided with a cutting blade provided so that the plane is along the rotation direction of the drum body, and the food waste scraped up by the lifter blade falls when it falls Feeding equipment. 7. The food material or feed production apparatus for food waste according to claim 6, wherein a part of the cutting blade is a twist blade twisted to the right or left at a substantially middle portion thereof.

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