Method for processing residual food in canteen into fertilizer

Abstract

The invention discloses a method for processing residual food in a canteen into a fertilizer, which comprises the following steps: carrying out impurity removal treatment and desalting treatment on collected canteen garbage containing leftovers, leftovers and sundries to remove the sundries and salt in the canteen garbage so as to obtain residual food in the canteen containing the leftovers; performing high-temperature sterilization treatment and stirring treatment on the residual food in the canteen; during the high-temperature sterilization treatment and stirring treatment of the residual food in the canteen, detecting the heating temperature of the residual food; according to the detected heating temperature and the high-temperature sterilization treatment time, the heating temperature is adjusted, and the remaining food in the canteen is processed into a sterile basic fertilizer which can be stored for a long time.

Description

Technical Field

[0001] The invention relates to a technology for processing leftovers, in particular to a method for processing leftover food in a canteen into fertilizer. Background Art

[0002] The leftover food in the canteen usually includes leftovers and leftover rice. The leftovers in the canteen are mainly meat and vegetables, supplemented by vegetables. Therefore, the leftovers in the canteen are high-protein substances and are very easy to rot. After the leftovers are rotten, they will cause very serious environmental pollution.

[0003] Existing canteen leftovers are usually collected in sour water buckets and supplied to pig farms as feed for pigs. However, canteen leftovers usually contain a large number of bacteria, which can infect pigs with certain diseases. If humans eat infected pork, it will bring harm to humans. In addition, the leftovers collected in sour water buckets will emit a very unpleasant odor, polluting the environment.

[0004] In addition, people use food waste disposers to deal with leftovers. The principle is to crush the leftovers and discharge the crushed leftovers into the sewer. The disadvantage is that it increases the load on the sewage treatment plant and causes blockage of the sewage pipe network. Summary of the invention

[0005] The first object of the present invention is to provide a method for processing cafeteria leftovers into fertilizers, which is used for processing cafeteria leftovers including leftovers into sterilized and dry fertilizers.

[0006] A second object of the present invention is to prevent overheating of cafeteria waste food during processing of cafeteria waste food including leftovers into sterilized and dry compost.

[0007] The large-scale method of processing canteen leftover food into fertilizer of the present invention for achieving the above-mentioned object comprises:

[0008] The canteen waste containing leftovers, rice and sundries is subjected to a de-impurity treatment and a de-salting treatment to remove the sundries and salt therein, thereby obtaining the canteen leftover food containing leftovers;

[0009] The remaining food in the cafeteria is subjected to high temperature sterilization and mixing treatment;

[0010] During the high-temperature sterilization and stirring process of the remaining food in the cafeteria, detecting the heating temperature of the remaining food;

[0011] According to the detected heating temperature and high-temperature sterilization treatment time, the heating temperature is adjusted to process the canteen's leftover food into sterile and long-term basal fertilizer;

[0012] The heating temperature is adjusted by changing the heating energy of the electric heating device.

[0013] Preferably, desalting the canteen leftover food comprises: placing the canteen garbage that has been decontaminated into a warm water pool for soaking, and using the warm water to absorb the salt components of the canteen garbage.

[0014] The method for processing canteen garbage into fertilizer of the present invention also includes: fermenting the basic fertilizer to form organic fertilizer; adding one or a combination of borax, vermiculite or perlite to the fermented organic fertilizer to form fertilizer for planting flowers.

[0015] Preferably, detecting the heating temperature of the leftover food includes: detecting the heating temperature at fixed time intervals during the high-temperature sterilization and stirring treatment of the leftover food in the cafeteria; comparing the currently detected heating temperature with the previously detected heating temperature to obtain a heating temperature increment.

[0016] Preferably, the high temperature sterilization treatment time includes an initial heating period and a high temperature sterilization period; in the initial heating period, the heating temperature is quickly increased to the high temperature sterilization temperature; in the high temperature sterilization period, the heating temperature is adjusted according to the obtained heating temperature increment.

[0017] According to one embodiment of the present invention, adjusting the heating temperature according to the detected heating temperature and high temperature sterilization treatment time includes:

[0018] During the initial heating period of the high-temperature sterilization treatment time, the heating temperature of the remaining food is quickly increased from a low temperature to a first heating temperature;

[0019] During the high-temperature sterilization period of the high-temperature sterilization treatment time, the obtained heating temperature increment is compared with a preset threshold value, and the first heating temperature is maintained or the heating temperature is reduced according to the comparison result;

[0020] The first heating temperature refers to a high temperature sterilization temperature that can achieve a sterilization effect.

[0021] Preferably, maintaining the first heating temperature or reducing the heating temperature according to the comparison result comprises:

[0022] If the heating temperature increment is lower than a preset threshold, maintaining the first heating temperature;

[0023] If the heating temperature increment is greater than or equal to a preset threshold, reducing the heating temperature from the first heating temperature to a second heating temperature;

[0024] Wherein, the second heating temperature is a drying temperature for drying the remaining food.

[0025] Preferably, the electric heating device comprises: a first electric heater group, a second electric heater group and a processor:

[0026] Wherein, the processor controls the power-on operation of the first electric heater group and the second electric heater group according to the comparison result of the detected heating temperature increment and the preset threshold value stored therein, so that the heating temperature reaches the first heating temperature or the second heating temperature.

[0027] According to another embodiment of the present invention, adjusting the heating temperature according to the detected heating temperature and high temperature sterilization treatment time includes:

[0028] During the initial heating period of the high-temperature sterilization treatment time, the heating temperature of the remaining food is quickly increased from room temperature to a first heating temperature;

[0029] During the high-temperature sterilization period of the high-temperature sterilization treatment time, the temperature increment of the remaining food is compared with a first preset threshold value, and if the temperature increment is higher than the first threshold value, the heating temperature is reduced from the first heating temperature to the second heating temperature, otherwise the first heating temperature is maintained;

[0030] Among them, the first heating temperature refers to a high-temperature sterilization temperature that can achieve a sterilization effect; the second heating temperature is a first drying temperature for drying leftover food.

[0031] Preferably, during the period when the heating temperature is reduced from the first heating temperature to the second heating temperature, the currently obtained temperature increment of the remaining food is compared with the second preset threshold value, and if it is higher than the second threshold value, the heating temperature is reduced from the second heating temperature to the third heating temperature, otherwise the second heating temperature is maintained;

[0032] The third heating temperature is the second drying temperature for drying the remaining food.

[0033] Preferably, the electric heating device comprises: a first electric heater group, a second electric heater group, a third electric heater group and a processor:

[0034] Among them, the processor controls the first electric heater, the second electric heater and the third electric heater to perform power-on operation based on the comparison result of the detected heating temperature increment with the first preset threshold value or the second preset threshold value saved therein, so that the heating temperature reaches the first heating temperature or the second heating temperature or the third heating temperature.

[0035] Preferably, a temperature sensor for detecting the heating temperature is provided in the processing container for heating the cafeteria leftover food.

[0036] Compared with the prior art, the beneficial technical effects of the present invention are:

[0037] 1) It can process the canteen leftover food that pollutes the environment and contains multiple pathogens into sterile and dry basic fertilizer;

[0038] 2) It is possible to avoid overheating of the canteen leftovers during the process of processing the canteen leftovers including leftovers into sterile and long-term basal fertilizers, because the present invention uses an electric heating device to sterilize the leftovers for a long time at high temperature, and the long-term high-temperature sterilization will make the leftovers easy to overheat, which may cause overheating accidents if not handled with care. The present invention detects the heating temperature of the high-temperature sterilization treatment to obtain the heating temperature increment, and adjusts the heating temperature according to the heating temperature increment and the high-temperature sterilization treatment time. The inventors have found through practice that the heating temperature increment is an important indicator for judging whether the canteen leftovers have reached the dryness level, and the heating temperature can be lowered according to the heating temperature increment, thereby avoiding overheating accidents in the process of processing the leftovers.

[0039] The present invention will be described in detail below with reference to specific embodiments in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 is a schematic diagram of a method for processing cafeteria leftover food into fertilizer according to the present invention;

[0041] Figure 2 It is a basic structural diagram of the canteen leftover food processing equipment for executing the canteen leftover food processing of the present invention;

[0042] Figure 3 Yes Figure 2 The schematic diagram of heating control of the electric heating device of the canteen leftover food processing equipment shown;

[0043] Figure 4 is a flow chart of a first embodiment of a processor-controlled electric heating device of the present invention;

[0044] Figure 5 is a schematic diagram of a first embodiment of an electric heating device for achieving high temperature heating according to the present invention;

[0045] Figure 6 is a flow chart of a second embodiment of a processor-controlled electric heating device of the present invention;

[0046] Figure 7 is a schematic diagram of a second embodiment of an electric heating device for achieving high temperature heating according to the present invention;

[0047] Figure 8 It is a schematic diagram of a warm water pool for desalination treatment according to the present invention. DETAILED DESCRIPTION

[0048] Figure 1 A method of processing canteen leftover food into fertilizer according to the present invention is shown, which comprises:

[0049] The canteen waste containing leftovers, rice and sundries is subjected to a de-impurity treatment and a de-salting treatment to remove the sundries and salt therein, that is, sundries such as toothpicks, plastics, glass, paper towels and salt in the canteen waste are removed to obtain canteen leftovers containing leftovers;

[0050] The canteen leftovers including leftovers and leftovers collected from the canteen are sterilized at high temperature. The heating temperature can be a standard sterilization temperature, such as 120°C-155°C. Usually, the heating temperature is inversely proportional to the heating time. The longer the heating time, the lower the heating temperature. Since the heating time of the present invention can last for several hours, the heating temperature can be equal to or greater than 100°C. The heating temperature of the present invention is provided by the electric heating device 104 described below. For the electric heating device 104 with multiple heating components, by controlling these heating components and changing the heating energy of the electric heating device 104, the heating temperature of the leftover food can be adjusted; or, by changing the heating power of the electric heating device 104, the heating energy of the electric heating device 104 can be changed to adjust the heating temperature of the leftover food. It should be pointed out that when the heating components of the electric heating device 104 remain unchanged or the heating power remains unchanged, the heating temperature can change with the change of the moisture content of the leftover food being heated. Generally speaking, the heating temperature of leftover food in a moist state is relatively stable, while the heating temperature of leftover food in a dry state will rise sharply. At this time, the power of the electric heating device 104 needs to be reduced in order to convert the high-temperature sterilization treatment to the drying treatment to prevent the leftover food from overheating accidents.

[0051] While the canteen leftover food is being sterilized at high temperature, the canteen leftover food is stirred. On the one hand, the canteen leftover food is evenly heated and sterilized without dead corners. On the other hand, the canteen leftover food is crushed into tiny particles. It should be noted that the leftover food is stirred during the high-temperature sterilization and drying processes.

[0052] During the high-temperature sterilization and stirring treatment of the cafeteria leftover food, the heating temperature of the heated leftover food is detected at fixed time intervals (the heating temperature of the present invention can be obtained by detecting the temperature of the leftover food), so as to judge whether the moisture in the cafeteria leftover food currently being processed has been fully evaporated and whether it can be dried (because the leftover food collected from the cafeteria is moist, when the moist leftover food is heated, the heating temperature is usually maintained at, for example, about 100°C. If the heating temperature changes, it means that the moisture content of the leftover food has been greatly reduced, or the leftover food has changed from a moist state to a dry state).

[0053] According to the detected heating temperature and high-temperature sterilization treatment time, the heating energy of the electric heating device is changed to adjust the heating temperature of the leftover food until the canteen leftover food is processed into a sterile basic fertilizer that can be stored for a long time; that is, if it is judged that the water in the canteen leftover food currently being processed has been fully evaporated and the canteen leftover food should be dried, the high-temperature sterilization temperature is adjusted to the drying treatment temperature, and the canteen leftover food is dried to make it a dry basic fertilizer that can be stored for a long time. Generally speaking, the heating temperature in the drying treatment stage is greater than or equal to 60°C.

[0054] As for the leftover food in the canteen kitchen, since the leftover food in the canteen kitchen usually does not contain salt, the present invention can process the canteen garbage into fertilizer through the following method, which includes: removing the debris from the collected canteen garbage containing leftovers, leftover rice and sundries, and obtaining the canteen leftover food containing leftovers; performing high-temperature sterilization on the canteen leftover food, and stirring the canteen leftover food at the same time; during the high-temperature sterilization and stirring of the canteen leftover food, detecting the heating temperature of the high-temperature sterilization treatment; adjusting the heating temperature according to the detected heating temperature and the high-temperature sterilization treatment time, and processing the canteen leftover food into sterile fertilizer that can be preserved for a long time.

[0055] The present invention can eliminate the pollution of the environment caused by canteen leftovers including leftovers and rice through the above method, because the processed canteen leftovers have become sterilized dry basic fertilizer, have no odor and can be stored for a long time without polluting water sources, soil and air.

[0056] In addition, the method of processing cafeteria garbage into fertilizer of the present invention also includes: fermenting the basic fertilizer to form organic fertilizer; adding an appropriate amount of borax, vermiculite or perlite or a combination thereof to the fermented organic fertilizer to form fertilizer for planting flowers or potted plants.

[0057] The present invention can also form a matrix for planting flowers or potted plants by adding an appropriate amount of borax, vermiculite or perlite or a combination thereof to the fermented organic fertilizer and then granulating the organic fertilizer.

[0058] On the other hand, the above method of the present invention can solve the technical problem of overheating, denaturation or charring of leftover canteen food during high-temperature sterilization, because the leftover canteen food after removing moisture is easy to overheat. In this case, the heating temperature will rise quickly, leading to overheating, denaturation or charring accidents.

[0059] The method of detecting the heating temperature of the leftover food (or the temperature of the leftover food in the cafeteria) of the present invention comprises: during the high-temperature sterilization and stirring treatment of the leftover food in the cafeteria, detecting the heating temperature of the leftover food at fixed time intervals, and saving the most recently detected or previously detected heating temperature;

[0060] The currently detected heating temperature is compared with the most recently detected or previously detected heating temperature to obtain a heating temperature increment.

[0061] For example, if the currently detected heating temperature is W t , the heating temperature W detected most recently or previously t-1 , then the heating temperature increment is: △W=W t -W t-1 .

[0062] The inventors conducted a large number of experiments and found that during the high-temperature sterilization of wet leftover food, a temperature inflection point will appear in the heating temperature or the temperature of the leftover food. The present invention finds the temperature inflection point through △W, determines whether the moisture in the wet leftover food has been removed, and then converts the high-temperature sterilization into a drying process.

[0063] Figure 2 The basic structure of the canteen leftover food processing device 100 for processing canteen leftover food of the present invention is shown, and the canteen leftover food processing device 100 includes:

[0064] a processing container 102, in which canteen leftover food including leftovers and rice collected from the canteen is placed;

[0065] An electric heating device 104 for heating the leftover food installed on the outer wall of the processing container 102, the electric heating device may be composed of a plurality of heaters arranged crosswise (described in detail below), and is used for high-temperature sterilization and drying of the canteen leftover food loaded into the processing container 102;

[0066] A stirring device installed in the processing container 102, used to turn over and crush the canteen leftover food loaded in the processing container 102;

[0067] A rotary drive device including a motor 111 and a transmission mechanism 103 installed at the bottom of the processing container 102 and connected to the stirring device is used to provide rotational power for the stirring device; the transmission mechanism 103 can transmit energy through mechanical parts such as gears, belts, chains, shafts, bearings, etc., such as a reducer.

[0068] A water vapor outlet 107 connected to the processing container 102 and used to discharge the water vapor in the processing container 102;

[0069] An air inlet 110 connected to the processing container 102 for introducing gas or air;

[0070] A plurality of temperature sensors 400 installed in the processing container 102 for detecting the heating temperature or the temperature of the remaining food in the processing container 102;

[0071] The processor 500 is used to adjust the heating temperature provided by the electric heating device 102 according to the heating temperature detected by the temperature sensor 400 and the high-temperature sterilization treatment time, until the remaining food in the cafeteria is processed into a sterile basic fertilizer that can be stored for a long time.

[0072] The canteen leftover food processing equipment 100 also includes: an air inlet 110 connected to the processing container 102; an air recovery device 300 connected to the water vapor outlet 107, which is used to purify the water vapor generated by the high-temperature sterilization of the canteen leftover food; a pot cover (not shown in the figure) added to the top of the processing container 102 to create a closed heating environment; a shell 101, in which the processing container 102, the electric heating device 104 and the rotating drive device are installed; and a discharge device (not shown in the figure) installed at the bottom of the processing container 102, which is used to discharge sterile and long-term basal fertilizer, and the discharge device may include a discharge hole and a discharge valve.

[0073] The processing container 102 is provided with a plurality of gas outlets 108 connected to the water vapor outlet passage 107, and the gas outlets 108 are arranged at intervals along the processing container 102. The water vapor outlet passage 107 includes an annular gas passage (not shown) continuously formed along the gas outlets 108 of the processing container 102 and an outlet gas passage extending from one point of the annular gas passage for connecting to the gas recovery device 300.

[0074] The processing container 102 is also provided with a plurality of air inlets 109 connected to the air inlet passage 110, which are arranged at intervals along the processing container 102. The air inlet passage 110 includes an annular air passage (not shown) continuously formed along the air inlets 109 of the processing container 102 and an air induction passage extending from one point of the annular air passage.

[0075] Figure 2 The stirring device shown includes a rotating shaft 105 and a stirring and crushing tool 106 fixed on the rotating shaft 105. Figure 2 The spiral cutter shown in is used to flip the leftovers and leftovers up and down, so that they are evenly heated, and while stirring, the leftovers and leftovers are crushed. The crushing cutter 106 can also adopt stirring cutters of other shapes.

[0076] The present invention performs desalination treatment on the canteen leftover food, comprising: placing the canteen leftover food into Figure 8The leftover food is soaked in the warm water pool 200 shown, and the warm water is used to absorb the salt content in the leftover food in the cafeteria, and then the leftover food in the cafeteria after desalination is placed in the processing container 102 for high-temperature sterilization and stirring. The warm water pool 200 includes a water inlet 201 and a drain outlet 201, and the drain outlet 201 is used to discharge the warm water that absorbs the salt content. If the salt content in the leftover food in the cafeteria is high, the present invention can also perform multiple desalination treatments on the leftover food in the cafeteria, that is, the desalination treatment is performed by soaking the leftover food in warm water multiple times.

[0077] The high temperature sterilization treatment time of the present invention includes an initial heating period and a high temperature sterilization period. In the initial heating period, the heating temperature is independent of the heating temperature of the remaining food. The initial heating period refers to the time period from when the electric heating device starts heating to when the temperature reaches 100°C. This period is mainly used to generate sufficient water vapor. In the high temperature sterilization period, according to the detected temperature increment of the remaining food or the heating temperature increment △W=W t -W t-1 Adjust the heating temperature.

[0078] According to the detected heating temperature increment △W = W t -W t-1 and high temperature sterilization treatment time, and adjusting the heating temperature of the remaining food comprises:

[0079] In the initial heating period of the high-temperature sterilization treatment time, the heating temperature of the remaining food is quickly increased from a low temperature to a first heating temperature, i.e., a high-temperature sterilization temperature; in the high-temperature sterilization period of the high-temperature sterilization treatment time, the currently detected heating temperature is compared with the most recently detected or previously detected heating temperature to obtain a heating temperature increment △W=W t -W t-1 , and according to the heating temperature increment △W=W t -W t-1 The first heating temperature is maintained or the heating temperature is reduced; wherein the first heating temperature is usually equal to or greater than 100°C.

[0080] Maintaining the first heating temperature or reducing the heating temperature according to the comparison result includes: the heating temperature increment ΔW=W t -W t-1 If the detected heating temperature of the remaining food is higher than or equal to the preset threshold (that is, the moisture content of the remaining food in the cafeteria is already very low), the heating temperature is reduced from the first heating temperature to the second heating temperature; wherein the second heating temperature may be, for example, 60±2°C.

[0081] Generally speaking, during the high-temperature sterilization stage, since the remaining food is relatively moist, the heating temperature is maintained at 100°C, and the heating temperature increment △W = W t -W t-1 is approximately zero, and at the time when the wet leftover food is heated to dry leftover food, the temperature of the leftover food will rise rapidly, for example, to 110°C, at which time the heating temperature increment △W=W t -W t-1 =110-100=10, so it is necessary to lower the heating temperature of the remaining food and enter the drying stage.

[0082] In another preferred embodiment of the present invention, the processor 500 pre-stores a threshold or presets a threshold value, and during the high-temperature sterilization and stirring of the canteen leftover food, receives the heating temperature detected by the temperature sensor 400, and subtracts the previous heating temperature from the current heating temperature, thereby obtaining the heating temperature increment △W=W t -W t-1 .

[0083] Figure 3 The present invention is shown to be useful for Figure 2 The schematic diagram of heating control of the electric heating device of the canteen leftover food processing equipment 100 is shown. The canteen leftover food processing equipment 100 sterilizes, dries and stirs the canteen leftover food at high temperature; the temperature sensor 400 detects the heating temperature of the canteen leftover food; the processor 500 obtains the heating temperature increment according to the heating temperature detected by the temperature sensor 400, and determines whether to maintain the high-temperature sterilization stage or enter the leftover food drying stage according to the heating temperature increment; in the leftover food high-temperature sterilization stage, the processor 500 maintains the heating heat energy of the electric heating device 104; in the leftover food drying stage, the processor 500 controls the electric heating device 104 to reduce its heating heat energy according to the predetermined time, thereby reducing the heating temperature of the leftover food, and cuts off the power supply of the electric heating device 104 after the predetermined time expires.

[0084] Since there can be multiple temperature sensors 400, the detected heating temperature is the root mean square value of the heating temperatures detected by these temperature sensors. That is, if there are n temperature sensors 400, the heating temperature detected by the first temperature sensor is W1, the heating temperature detected by the second temperature sensor is W2, and the heating temperature detected by the nth temperature sensor is W n , then the detected heating temperature W is:

[0085] .

[0086] Figure 4The process of the processor 500 of the present invention controlling the first embodiment of the electric heating device 302 is shown, and the process starts at step S101. In step S102, the processor 500 raises the heating temperature of the electric heating device 104 to the high-temperature sterilization temperature, and then receives the heating temperature detected by the temperature sensor 400 at a fixed time interval, and then the process enters step or processing S103. In step S103, the processor 500 compares the heating temperature currently detected by the temperature sensor 400 with the heating temperature previously measured by the temperature sensor to obtain the heating temperature increment △W, and then the process enters step S104. In step S104, it is judged whether the heating temperature increment is greater than or equal to a preset threshold (if the preset threshold is 5 and △W is 9, it is judged that △W is greater than the preset threshold). If so, it means that the moisture in the canteen leftover food treated with high-temperature sterilization has been fully evaporated, and the process enters step S105; if not, it means that the moisture in the canteen leftover food has not been fully evaporated, and the process enters step S106. In step S105, the processor 500 issues an instruction to reduce the power of the electric heating device, so that the heating temperature of the electric heating device 104 is reduced from the high-temperature sterilization temperature to the drying temperature, and then the process ends in step S107. In step S106, the electric heating device 104 is kept at the high-temperature sterilization temperature, and then the process returns to step S103.

[0087] Figure 5 The first embodiment of the electric heating device 104 for achieving high temperature heating of the present invention is shown, and the electric heating device 104 comprises: a plurality of first electric heaters 1041, a plurality of second electric heaters 1042 and a processor 500. Figure 5 As shown, the plurality of first electric heaters 1041 and the plurality of second electric heaters 1042 are cross-arranged, and are respectively powered on and off by the processor 500. Specifically, the processor 500 controls the first electric heater group composed of the plurality of first electric heaters 1041 and the plurality of second electric heaters 1042 to perform power-on operations based on the comparison result of the detected heating temperature of the remaining food with the preset threshold value stored therein, so that the heating temperature reaches the first heating temperature or the second heating temperature; for example, when the first electric heater group and the second electric heater are powered on at the same time, the heating temperature can reach the first heating temperature; when the first electric heater group is heated and the second electric heater is powered off, the heating temperature reaches the second heating temperature.

[0088] As an example, the processor 500 controls the Figure 7 The two first electric heaters 1041 and the two second electric heaters 1042 are powered on at the same time, so that the heating temperature reaches the first heating temperature; by controlling the two first electric heaters 1041 to perform a power-off operation and controlling the second electric heaters 1042 to perform a power-on operation, the heating temperature is reduced from the first heating temperature to the second heating temperature.

[0089] Figure 6 The flowchart of the second embodiment of the processor 500 of the present invention controlling the electric heating device 104 is shown, and the process starts at step S201. In step S202, the processor 500 raises the heating temperature of the electric heating device 104 to the first heating temperature (i.e., the high-temperature sterilization temperature), receives the heating temperature detected by the temperature sensor 400 at a fixed time interval, and then the process enters step or processing S203. In step S203, the processor 500 compares the heating temperature currently detected by the temperature sensor with the heating temperature detected most recently, and obtains the heating temperature increment △W. Then the process enters step S204 to determine whether the heating temperature increment of the temperature sensor 400 at the first heating temperature is greater than the first preset threshold. If so, it indicates that the moisture content of the canteen leftover food treated by high-temperature sterilization begins to decrease, and the process enters step S206; if not, it indicates that the moisture content of the canteen leftover food treated by high-temperature sterilization is high, and the process enters step S205. In step S205, the processor 500 keeps the electric heating device 104 at the first heating temperature. In step S206, the processor 500 issues a control instruction to reduce the heating temperature of the electric heating device 104 from the first heating temperature to the second heating temperature (i.e., the first drying temperature), and then the process enters step S207. In step S207, the processor 500 obtains the heating temperature increment at the second heating temperature (i.e., the difference between the currently detected heating temperature at the second heating temperature and the most recently detected heating temperature) from the temperature sensor 400, and then the process advances to step S208. In step S208, the processor 500 determines whether the heating temperature increment at the second heating temperature is greater than or equal to a second preset threshold value (for example, the second preset threshold value is 4). If so, the process enters step S210, and if not, the process enters step S209. In step S209, the processor 500 keeps the electric heating device 104 at the second heating temperature. In step S210, the processor 500 issues a control instruction to reduce the heating temperature of the electric heating device 104 from the second heating temperature to the third heating temperature (i.e., the second drying temperature), and then the process ends in step S211. In this embodiment, the second drying temperature is lower than the first drying temperature, for example, the first drying temperature is 80±5°C, and the second drying temperature is 60±2°C.

[0090] Figure 7 Shows suitable for Figure 6 The electric heating device 104 of the embodiment of the process shown in FIG. 1 includes: a plurality of first electric heaters 1041, a plurality of second electric heaters 1042, a plurality of third heaters 1043, and a processor 500. Figure 7As shown, a plurality of first electric heaters 1041, a plurality of second electric heaters 1042 and a plurality of third heaters 1043 are cross-arranged, and are powered on by the processor 500. The processor 500 controls the first electric heater group composed of the plurality of first electric heaters 1041, the second electric heater group composed of the plurality of second electric heaters 1042 and the third heater group composed of the plurality of third electric heaters to perform a power-off operation according to the comparison result of the detected heating temperature with the first preset threshold value or the second preset threshold value stored therein, so that the heating temperature reaches the first heating temperature or the second heating temperature or the third heating temperature; for example, when the first electric heater group, the second electric heater group and the third heater group are powered on at the same time, the heating temperature can reach the first heating temperature; when the first electric heater group and the second electric heater group are powered on and the third heater group is powered off, the heating temperature drops to the second heating temperature; when the first electric heater group is powered on and the second electric heater group and the third heater group are powered off, the heating temperature drops to the third heating temperature.

[0091] Specifically, during the initial heating period of the high-temperature sterilization treatment time, the heating temperature of the remaining food is quickly increased from room temperature to a first heating temperature; during the high-temperature sterilization period of the high-temperature sterilization treatment time, the detected heating temperature is compared with a first preset threshold value, and the first heating temperature is maintained or the heating temperature is reduced based on the comparison result; wherein the first heating temperature is 100°C or approximately 100.

[0092] More specifically, if the detected heating temperature increment is greater than or equal to the first preset threshold, the first heating temperature is reduced to the second heating temperature; if the detected heating temperature increment is lower than the first preset threshold, the heating temperature is maintained at the first heating temperature. At the second heating temperature, the processor 500 compares the heating temperature increment with the second preset threshold, and if the heating temperature increment at the second heating temperature is greater than or equal to the second preset threshold, the heating temperature is reduced from the second heating temperature to the third heating temperature; if the heating temperature increment at the second heating temperature is less than the second preset threshold, the second heating temperature is maintained; wherein the third heating temperature is a heating temperature lower than the second heating temperature, for example, the second heating temperature is 80±5°C and the second heating temperature is 60±2°C.

[0093] In addition, the electric heater 104 of the present invention may also be an electromagnetic heater, and the heating temperature can be controlled by controlling its heating power.

[0094] It should be noted that the term "canteen" in the present invention is synonymous with restaurant, hotel and restaurant.

[0095] In summary, the present invention can process cafeteria leftover food that pollutes the environment and contains multiple pathogens into sterile organic fertilizer that is beneficial to environmental protection; and the present invention can also prevent cafeteria leftover food from overheating during the process of processing cafeteria leftover food including leftovers into sterilized dry fertilizer.

[0096] Although the present invention is described in detail above, the present invention is not limited thereto, and those skilled in the art can make various modifications based on the principles of the present invention. Therefore, all modifications made based on the principles of the present invention should be understood to fall within the protection scope of the present invention.

Claims

1. A method for processing canteen leftover food into fertilizer, comprising: The canteen waste containing leftovers, rice and sundries is subjected to a de-impurity treatment and a de-salting treatment to remove the sundries and salt therein, thereby obtaining the canteen leftover food containing leftovers; The remaining food in the cafeteria is subjected to high temperature sterilization and mixing treatment; During the high-temperature sterilization and stirring process of the remaining food in the cafeteria, detecting the heating temperature of the remaining food; According to the detected heating temperature and high-temperature sterilization treatment time, the heating temperature is adjusted to process the canteen leftover food into a sterile basic fertilizer that can be stored for a long time; The heating temperature is adjusted by changing the heating energy of the electric heating device.

2. The method for treating canteen garbage into fertilizer according to claim 1, wherein: The method of desalting the canteen leftover food comprises: placing the canteen garbage after impurity treatment into a warm water pool for soaking, and utilizing the warm water to absorb the salt components of the canteen garbage.

3. The method for treating dining hall garbage into fertilizer according to claim 2 further comprises: Fermenting the basic fertilizer to form organic fertilizer; Add borax, vermiculite or perlite or a combination of them to the fermented organic fertilizer to form a fertilizer for growing flowers.

4. The method for treating canteen garbage into fertilizer according to claim 1, wherein: Detecting the heating temperature of the remaining food includes: During the high-temperature sterilization and stirring of the canteen leftover food, detecting the heating temperature at fixed time intervals; The currently detected heating temperature is compared with the previously detected heating temperature to obtain a heating temperature increment.

5. The method for treating canteen garbage into fertilizer according to claim 4, wherein: The high temperature sterilization treatment time includes an initial heating period and a high temperature sterilization period; During the initial heating period, the heating temperature is quickly raised to the high temperature sterilization temperature; During the high temperature sterilization period, the heating temperature is adjusted according to the obtained heating temperature increment.

6. The method for treating cafeteria garbage into fertilizer according to claim 5, wherein: The step of adjusting the heating temperature according to the detected heating temperature and high temperature sterilization treatment time includes: During the initial heating period of the high-temperature sterilization treatment time, the heating temperature of the remaining food is quickly increased from a low temperature to a first heating temperature; During the high-temperature sterilization period of the high-temperature sterilization treatment time, the obtained heating temperature increment is compared with a preset threshold value, and the first heating temperature is maintained or the heating temperature is reduced according to the comparison result; The first heating temperature refers to a high temperature sterilization temperature that can achieve a sterilization effect.

7. The method for treating cafeteria garbage into fertilizer according to claim 6, wherein: Maintaining the first heating temperature or reducing the heating temperature according to the comparison result includes: If the heating temperature increment is lower than a preset threshold, maintaining the first heating temperature; If the heating temperature increment is greater than or equal to a preset threshold, reducing the heating temperature from the first heating temperature to a second heating temperature; Wherein, the second heating temperature is a drying temperature for drying the remaining food.

8. The method for treating canteen garbage into fertilizer according to claim 7, wherein: The electric heating device comprises: a first electric heater group, a second electric heater group and a processor: Wherein, the processor controls the power-on operation of the first electric heater group and the second electric heater group according to the comparison result of the detected heating temperature increment and the preset threshold value stored therein, so that the heating temperature reaches the first heating temperature or the second heating temperature.

9. The method for treating cafeteria garbage into fertilizer according to claim 5, wherein: The step of adjusting the heating temperature according to the detected heating temperature and high temperature sterilization treatment time includes: During the initial heating period of the high-temperature sterilization treatment time, the heating temperature of the remaining food is quickly increased from room temperature to a first heating temperature; During the high-temperature sterilization period of the high-temperature sterilization treatment time, the temperature increment of the remaining food is compared with a first preset threshold value, and if the temperature increment is higher than the first threshold value, the heating temperature is reduced from the first heating temperature to the second heating temperature, otherwise the first heating temperature is maintained; Among them, the first heating temperature refers to a high-temperature sterilization temperature that can achieve a sterilization effect; the second heating temperature is a first drying temperature for drying leftover food.

10. The method for treating cafeteria garbage into fertilizer according to claim 9, wherein: During the period when the heating temperature is reduced from the first heating temperature to the second heating temperature, the currently obtained temperature increment of the remaining food is compared with the second preset threshold value, if it is higher than the second threshold value, the heating temperature is reduced from the second heating temperature to the third heating temperature, otherwise the second heating temperature is maintained; The third heating temperature is the second drying temperature for drying the remaining food.

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