RU2071458C1 - Method and apparatus for preparing fertilizer from organic wastes - Google Patents

Abstract

FIELD: utilization of wastes. SUBSTANCE: mixture of chicken droppings with moisture-absorbing material is irradiated with superhigh-frequency emission and charged at 70-80 C into a reactor where the mixture is subjected to blowing through with oxygen- containing gas in upward and transverse directions with continuous removal of worked out gas. The mixture is further kept at 70-80 C for 60-70 h and discharged as final product, which is dried to 20- 25% of moisture. Method is carried out in apparatus 1 consisting of accumulator 2, rotor conveyer 6, superhigh-frequency emitter 7, reactor 8 with windows for charging raw material 4 and discharging final product 5. Reactor 8 is provided with system 13 for blowing through oxygen-containing gas, system for removing worked out gas from reactor, and dryer 20 for afterdrying of final product. EFFECT: enhanced efficiency of process. 3 cl, 2 tbl

Description

 The invention relates to agriculture, more specifically to the production of fertilizers, and can be used for the preparation of environmentally friendly fertilizers from organic waste, in particular chicken manure.

 A known method of producing natural fertilizer (compost) from biomass, including the natural mixing of farm animals waste with their litter, or many other agricultural waste with moisture-absorbing material (sawdust, straw), the formation of collars from the above mixtures, the fermentation of this mixture in collars by electrolysis carried out using electropositive and electronegative electrodes of various shapes and sizes introduced into the processed raw materials (application Fra tion N 2516503, cl. IPC C 05 F 11/08, publ. 05.20.83).

 The disadvantage of this method is its considerable duration, since the temperature of only the thermophilic phase the mixture is reached in a few days under any processing conditions, and to obtain a fully finished product, it is necessary to maintain the mixture at this temperature. Another disadvantage of this method is its energy intensity due to the operation of electrolysis.

 A known fermenter for fermentation of organic raw materials containing a chamber for fermentation, an inlet for supplying raw materials, tubular baffles along the vertical chamber for supporting raw materials, vertical feeders of the chamber for supplying oxygen-containing gas in the direction from bottom to top and top to bottom and an outlet for unloading the finished product. Oxygen-containing gas feeders have spray holes in the tubular partitions, while the air pressure tubes are connected to these partitions and two compressors for supplying compressed air. At the bottom of the chamber for the convenience of unloading the finished product, a blade unloader is installed (A. Japanese application N 64-9275, class MKI S 05 F 3/06, C 12 M 1/16, publ. 02.16.89).

 The disadvantages of this device include its significant energy consumption, due to the presence of two powerful compressors for supplying oxygen-containing gas to the processed mass, one of which operates under high pressure, and an additional paddle unloader, powered by a stand-alone engine.

 The disadvantages of this device also include its low productivity, due to the length of the processing process of processed raw materials. This is explained by the fact that despite the presence of several tiers of feeders supplying oxygen-containing gas to the treated mass, not all of its mass is evenly aerated due to the volume of raw materials loaded for processing, which increases the exposure time of the raw materials in the reactor to obtain the finished product.

A known method of composting organic waste, selected as a prototype and comprising mixing organic waste with a moisture-absorbing material, in particular with straw, rice husk or sawdust to a moisture content of 40-60%, loading it into the first drive, unloading this mixture from the drive onto a conveyor, sealing and leveling the unloaded mixture with a special roller, irradiating the mixture located on the conveyor with electron beams, unloading the irradiated mixture into an intermediate storage, then loading it into the reaction op, adding to the charged mixture fermenting microorganisms, mixing this mixture with a paddle stirrer, purge it with filtered oxygen-containing gas in the upward direction, the shutter speed of processing raw material in the reactor for 1-3 days at 40-60 ^o C, and unloading the resulting product ( A. Japanese application N 58-30274, class MKI C 05 F 9/00, 3/00, 7/00, publ. 28.06.83).

 The disadvantages of this method are its significant duration, complexity and increased cost. This is due to the presence of many additional operations in this method: pressing and leveling the mixture in height on a conveyor, introducing fermenting microorganisms into the mixture, mixing the mixture, and filtering the oxygen-containing gas supplied.

 Pressing and leveling the mixture on the conveyor before irradiation is caused by the fact that the electron irradiation forces are enough only for a certain thickness of the raw material.

 The introduction of fermenting microorganisms is caused by the fact that after electron irradiation the treated mass cannot be fermented.

 The mixing of the mixture of processed raw materials with microorganisms introduced into it is caused by the fact that these microorganisms must be evenly distributed throughout the mass so that the processing process proceeds uniformly throughout the volume.

 The filtration of oxygen-containing gas is caused by the fact that after irradiation, the raw material is sterilized, and in order not to pollute it with pathogenic microorganisms in the air, it is filtered before it is fed to the reactor.

 A device for composting organic waste, selected as a prototype, is known, consisting of a store of mixed raw materials, electronic irradiation, a line for supplying irradiated raw materials from a store to a reactor, consisting of a conveyor with a compacting roller, an intermediate store for irradiated raw materials and a device for supplying irradiated materials to the reactor, reactor with holes for loading the processed raw materials and unloading the finished product, devices for feeding microorganisms to the fermentation reactor, paddle mixer, system supplying oxygen-containing gas to the processed raw materials to the lower part of the reactor and connected to the discharge unit, a filter for purifying the oxygen-containing gas supplied and controlling the temperature and air composition of devices (a. Japanese application No. 58-30274, class MKI C 05 F 9/00, 3 / 00, 7/00, publ. 06/28/83).

 The disadvantages of this device include the complexity of the hardware design and its significant energy consumption, which is associated with the presence of a known device with additional devices that complicate it and require the consumption of additional electricity. This is a crushing roller on the conveyor, a device for feeding fermenting microorganisms to the reactor, a paddle mixer and a filter for cleaning the oxygen-containing gas entering the reactor.

 Another disadvantage of this device is its lack of productivity, caused by the small capacity of the reactor, which is associated with the cyclical nature of its operation. Each time after the end of the digestion cycle, the reactor is stopped, the resulting product is extracted and a new batch of processed raw materials is loaded into it, a new portion of fermenting microorganisms is added and this mixture is mixed and purged with purified oxygen-containing gas. All this increases the total time of the full cycle and naturally decreases the performance of the device.

 The objective of the invention is to provide a simple cheap and less durable method, providing environmentally friendly fertilizer suitable for transportation and long-term storage.

 In addition, the object of the invention is to provide a simple device with low energy consumption and sufficient performance.

The proposed method for producing fertilizers from organic waste, including mixing them with a moisture-absorbing material, irradiating a wet mixture, loading the irradiated raw materials into the reactor, blowing them with oxygen-containing gas in the direction from the bottom up, followed by holding the processed raw materials in a temperature-time mode and unloading the finished product, according to the invention the reactor is charged with irradiated feed temperature of 70-80 ^o C, irradiation of the wet mixture is carried out using microwave rays purge feedstock gas containing oxygen d additionally carried out in the transverse direction with a constant removal of the reactor exhaust gas containing oxygen, raw extract in a reaction zone is carried out for 60-70 hours at the same temperature, and the finished product is discharged finally dried to a moisture content of 20-25%
The proposed method is simpler, cheaper and less time consuming, firstly, by reducing the number of operations that take place in the known method, such as
pressing and leveling on the conveyor mixture before irradiation, since the microwave rays in the proposed method are able to penetrate into any thickness of the raw material;
the introduction of a mixture of fermenting microorganisms, since the feed entering the reactor in the proposed method already has a fermentation temperature, and irradiation with microwave radiation activates the growth of thermophilic bacteria;
mixing the treated mixture with fermenting microorganisms, since, as mentioned above, microwave irradiation activates the growth of thermophilic bacteria, which in turn activates the fermentation process;
filtration of oxygen-containing gas, since microwave irradiation and fermentation at 70-80 ^o C for 60-70 hours reliably guarantees the destruction of helminths, weed seeds and pathogenic microorganisms.

Secondly, tests carried out at an industrial poultry farm with unprotected poultry keeping for processing poultry manure by the proposed method showed that increasing the temperature of the mixture before loading it into the reactor to 70-80 ^o C, irradiation of this mixture with microwave radiation dramatically activates the growth of thermophilic bacteria that allows you to create optimal conditions for reducing the period of fermentation. A preliminary increase in the temperature of the raw material makes it possible to create a temperature uniform throughout the volume in the reactor and thereby significantly reduce the reaction time of aerobic decomposition. The implementation of aerobic decomposition at 70-80 ^o C for 60-70 hours is enough to quickly turn the mixture into a high-quality product, without significant loss of nutrients, especially nitrogen. In addition, irradiation of raw materials with microwave rays can significantly reduce the degree of contamination of the mixture entering the reactor with helminth eggs, weed seeds and pathogenic microorganisms. The same tests showed that additional blowing of the feedstock with oxygen-containing gas in the transverse direction with constant removal of the spent oxygen-containing gas from the reactor ensures the creation of optimal conditions for aerobic decomposition, also allows the fermentation process to be uniform throughout the volume and to obtain a finished product in 60-70 hours, which after additional drying to a moisture content of 20-25%, it is a high-quality fertilizer suitable for transportation and long-term storage.

 The proposed device for producing fertilizer is simple, has a small energy consumption and sufficient performance.

 This is achieved, firstly, due to the fact that the proposed device eliminates such nodes that make the known device complex and energy-intensive, such as a crushing roller on a conveyor, a device for supplying fermenting microorganisms to the reactor, a paddle mixer, and an oxygen-containing gas purification filter.

 Secondly, due to the significantly greater throughput of the proposed device, due to its continuous operation.

 The set of features of the proposed method differs from the prototype and does not follow explicitly from the studied prior art, therefore, the method is new and has an inventive step.

 The method can be widely used in industries engaged in the production of fertilizers, i.e. is industrially applicable.

 The set of features of the proposed device has differences from the prototype and does not follow explicitly from the studied prior art, therefore, the device is new and has an inventive step.

 This device can be widely used in agriculture, i.e. is industrially applicable.

 The essence of the method of producing fertilizer from organic waste is illustrated by the flowchart and tables with test results.

 Figure 1 shows a diagram of the technological process of obtaining fertilizer from organic waste; figure 2 and 3, the connection of the process pipes in the oxygen-containing gas supply system and the location of the holes for supplying it in the direction from the bottom up and in the transverse direction.

 Table 1 presents the test results, reflecting the influence of various parameters of the regime on the conditions and quality of the resulting product; Table 2 shows the test results, reflecting the merging of the moisture content of the obtained product during storage and the quality of the fertilizer.

 Chicken manure from an industrial poultry farm with unprotected poultry is collected in a warehouse from which raw materials are loaded in portions into a thickener centrifuge to remove excess moisture. Partially dehydrated manure is loaded from a centrifuge into an OS-40 mixer, where moisture-absorbing material (sawdust, straw, peat) is fed and mixed thoroughly. To remove foreign matter, the mixture is passed through a screen, after which the crushed and mixed raw materials enter the drive. The mixture thus treated has a uniform composition with a particle size of up to 12 mm, a moisture content of 50-55% and a C ratio of 1:25.

In the lower layers of the wet mixture in the drive under the action of fermophilic bacteria present in the feed, fermentation begins, which causes an increase in the temperature of the mixture. By the time of loading into the reactor, the temperature of the mixture in the lower layers of the accumulator reaches 70-80 ^o C. From the accumulator using the rotary conveyor, the heated lower layers of the wet mixture begin to rise into the reactor. When lifting this mixture, it is irradiated with the help of microwave rays emitted by the device. The irradiation intensity is 2.7–9 MHz, length is 19–30 cm. The mixture thus treated is loaded into the reactor.

 The mixture is loaded into the reactor to its full height, after which the mixture is purged with oxygen-containing gas, for example air, in two directions: from the bottom up and in the transverse direction with the constant removal of the spent oxygen-containing gas from the reactor.

 The supply of oxygen-containing gas to the reactor in the direction from the bottom up is carried out through holes with a diameter of 8-15 mm, made in technological pipes with a diameter of 76 mm, located at a distance of 467 mm from each other over the entire width of the reactor. These process pipes are located, for example, in two tiers, the distance between which is 980 mm.

 The supply of oxygen-containing gas in the transverse direction is carried out through similar openings made in similar process pipes, but located along the perimeter of the reactor, for example, in two rows with a distance between them also of 980 mm.

 The process pipes of the system for supplying oxygen-containing gas to the reactor in the direction from the bottom up and in the transverse direction are made in one piece: the process pipes of each of the tiers are jumpers for process pipes located around the perimeter. Oxygen-containing gas through a collector into which all process pipes are brought together comes from an injection system such as VD or OKS.

 The supply of oxygen-containing gas to the reactor is controlled by means of dampers installed on this system, and NPM-type gravimetric meters installed on process pipes.

With the flow of oxygen-containing gas into the reactor, it begins an intensive process of biological decomposition at a temperature of incoming raw materials of 70-80 ^o C for 60-70 hours

Maintaining the temperature in the reactor at a level of 70-80 ^o With the regulation of the amount of air supplied at the time of its supply. With an increase or decrease in temperature in the reactor, which is controlled by temperature sensors with Sh-69000 lagometers, the air supply time, and therefore its quantity, either increases or decreases.

 The oxygen-containing gas passed through the mixture is removed from the reactor and discharged from the reactor through the drainage system. The drainage system is made in the form of technological pipes with a diameter of 89 mm with holes in their lower part, the number and diameter of which are much larger than in the discharge system. It is located, for example, in two tiers along the entire width of the reactor and along its perimeter beneath the oxygen-containing gas supply system.

 The percentage of oxygen in the processed mass is controlled using a gas analyzer of the type AG-0011, which communicates with the internal volume of the reactor using an intake pipe.

The signal of product readiness is a drop in temperature to 30 ^o C in the mass, which is also controlled by 6-8 temperature sensors with lagometers Ш-69000.

 Unloading of the finished product is as follows. Every 30 minutes, a discharge conveyor is installed, installed under the discharge opening, and part of the finished product falls on it and then goes to the drying drum for drying and then to the packing station. At the time of unloading a portion of the finished product, the mass of raw materials in the reactor settles. At the same moment, the loading rotor conveyor is simultaneously switched on, a new portion of the feed, equal in weight to the unloaded, falls into the reactor. The mass volume in the reactor is restored.

 Dosage of the finished product is carried out in a drying drum installed after the discharge conveyor.

 Ready-made fertilizer is a loose mass, convenient for transportation, packaging and application to the soil. In different doses, it is applicable to all soils and under all plants.

 The results of experiments on the preparation of fertilizer from bird droppings at various temperatures of the feed entering the reactor are given in examples 1-% (see table. 1).

As can be seen from the data in table 1, the least time spent, subject to the requirements for fertilizer quality, the process is achieved by increasing the temperature of the irradiated mixture before loading it into the reactor to 70-80 ^o C (example 1, 5, 4). At values of this temperature of 70 ^o With increases the total residence time of the mixture in the reactor, which significantly impairs the quality indicators of the finished fertilizer (example 2). The increase in this temperature of 80 ^o With, although it reduces the total residence time of the treated mixture in the reactor, but in the end significantly affects the quality of the finished fertilizer (example 3).

 In the experiments described in examples 6-10 (see table 1), the optimal temperature required for the microbiological decomposition process was studied.

 In the experiments described in examples 6-10 (see table 1), the optimal temperature necessary for the implementation of the microbiological decomposition process was studied.

It was experimentally determined that the optimal temperatures necessary for the full cycle of microbiological decomposition are temperatures from 70 to 80 ^o C. When carrying out the process at these temperatures, all other things being equal, received high-quality fertilizer. When the temperature in the reactor is artificially lowered to 70 ^° C, the residence time of the raw material in the reaction zone increases sharply, as a result of which the quality of the finished product deteriorates, in particular, nutrients are significantly lost. When the temperature in the reactor is increased to 80 ^o C, the residence time of the raw material in the reactor decreases, but the quality of the finished product significantly deteriorates.

 In the experiments described in examples 11-15, the residence time of the raw material in the reactor, necessary for the implementation of the full cycle of microbiological decomposition, was determined. The results of the experiments presented in table 1.

 It was experimentally established that the most effective microbiological process was carried out in 60-70 hours (examples 11, 14, 15). If the residence time of the raw material in the reactor is reduced to 60 hours, then a complete microbiological decomposition cycle will not occur and as a result, defective fertilizer with pathogenic bacteria will result. The product will not be suitable for long-term storage and transportation.

 Lengthening the process up to 70 hours will also not bring positive results, since the finished fertilizer will be in the reactor, and a long stay in the elevated temperature zone significantly worsens the quality indicators of the finished product (example 13).

 Example 16 reflects the picture of the process in the reactor in the absence of preliminary irradiation of raw materials before loading it into the reactor. Experience has shown that even when raw materials enter the reactor at the optimum temperature, the residence time of unirradiated raw materials in the reactor increases to full readiness. In addition, the finished product does not meet the requirements for the quality of the finished product.

 In the absence of the operation of purging the raw materials in the reactor in the transverse direction, the residence time of the irradiated raw materials in the reaction zone also increases, which significantly impairs the quality of the finished product (example 17).

 Examples 18-22 show studies that reflect the pattern of the process in the reactor in the absence of an operation to remove spent oxygen-containing gas. Studies have shown that, ceteris paribus, the absence of an operation to remove the spent oxygen-containing gas significantly reduces the fermentation rate and thereby increases the residence time of the raw materials in the reactor (examples 19, 20), which significantly degrades the quality of the finished product.

 Table 2 summarizes the tests carried out with the finished product discharged from the reactor after the completion of the fermentation process. The experiments established that the optimum humidity at which the quality of the finished fertilizer is maintained after long-term storage is 20-25% humidity (examples 1, 4, 5). Tests were conducted for 12 months). With an increase in the humidity of the finished product to 25%, the fertilizer became moldy for a short period of time and lost its quality indicators (Example 2), and when the fertilizer was dried up to 20%, it lost valuable nutrients and was poorly applied to the soil.

Thus, the results of the experiments showed that the optimum temperature at which it is necessary to load the feed into the reactor is 70-80 ^o C.

The device in which the above method is carried out consists of a drive 1 of raw materials 2 installed below the floor level. The accumulator 1 has an opening 3 for loading and an opening 4 for unloading the mixture 2. In the accumulator 1, a rotary conveyor 5 is installed, over which a microwave irradiator is placed 6. The reactor 7 is a vessel with axial dimensions of 4.0 • 6.0 • 6.0 m . In the lower part, the side walls of the reactor 7 go into inclined planes with an angle to the horizon of 45 ^o . The gap between the inclined planes is 1.0 m. The reactor 7, the basis of which is a frame of channel N 12-14, is made entirely of metal, the inner surface of the frame is lined with stainless steel, the outer black sheet.

The space between the inner and outer claddings is filled with insulation based on the calculation of the minimum heat transfer at a temperature difference of 70–80 ^o C.

 In the upper part of the reactor 7 there is a loading hole 8 for loading the irradiated raw materials 9, in the lower part a discharge opening 10 for unloading the finished product 11.

 The reactor 7 is equipped with a system 12 for supplying oxygen-containing gas to the reactor in the direction from the bottom up and in the transverse direction. This system is connected to discharge and exhaust manifolds (not shown). The system 12 for supplying oxygen-containing gas in the direction from the bottom up is made in the form of two or more tiers I and II of the technological tubes 13, 13 ', 13 ". With holes 14, 14', 14". in the upper part and for supplying oxygen-containing gas in the transverse direction, it is additionally equipped with 2 or more rows of process tubes 15, 15 ', 15 "installed along the perimeter of the reactor 7 and made with it in one piece with openings 16, 16', 16". on the inner side surface.

 The distance between the I and II tiers and between the rows of technological tubes 13, 15 is 980 mm, the distance between the technological tubes inside the I and II tiers is 467 mm.

 The reactor 7 is also equipped with a drainage system 17 for exhausting oxygen-containing gas, which is made in the form of process pipes 17, 17 ', 17 ". With holes 18, 18', 18". in their lower part and located for example in two tiers along the entire width of the reactor and along its perimeter under an oxygen-containing gas supply system 12.

 A discharge conveyor 19 is installed under the discharge opening 10 of the reactor 7, from which the finished product enters the drying drum 20 installed behind it.

 The device is equipped with devices that control the temperature and composition of the air (not shown).

 The device operates as follows.

 Wet raw materials 2 from drive 1 are conveyed by rotary conveyor 6 to feed port 8 of reactor 7. Raw materials 2, located on the blades of conveyor 5, are irradiated with a microwave irradiator similar to that used in domestic microwave ovens installed above it.

 Microwave irradiation of the feedstock 2 enters the reactor 7 and fills it to its full height.

 Then, the system 12 for supplying oxygen-containing gas to the processed raw materials and the simultaneous drainage system for exhausting oxygen-containing gas from the reactor are turned on. The finished product is discharged from the reactor through the discharge opening 9, enters the discharge conveyor, from which it enters the drying drum 20, from which it is discharged for subsequent packaging.

 The device is equipped with an automatic control system that monitors the processing process and, when the processing product is ready, gives a signal to synchronously turn on the discharge and loading conveyor. For example, after 30 minutes, both the discharge conveyor 16 and the loading rotor conveyor 5 are turned on, and part of the finished product 11 falls on the discharge conveyor 19. The mass of raw material 2 in the reactor 7 settles, but with a new portion of the raw material from the accumulator 1, the volume of the processed raw material in the reactor 7 is being restored.

 This device is easily mounted and dismantled and in disassembled form takes up little space, which makes it mobile. This allows you to move it at any distance and use it on almost any poultry farm. In this case, the device can be configured both for continuous operation and for periodic operation, depending on the amount of processed raw materials. The energy intensity of production of 1 ton of products is 0.63 kW of electricity.

 The device is made of non-deficient material.

 The presence of an automatic control system allows the use of 1 operator for its service.

 Using the proposed method of processing organic fertilizer into fertilizer and a device for its implementation allows for a short period of time to process a significant amount of organic waste accumulating in industrial sites of poultry farms, which allows one of the most important environmental problems in these industries to be solved.

Claims (1)

1. A method of producing fertilizers from organic waste, including mixing them with moisture-absorbing material, irradiating a wet mixture, loading the irradiated raw materials into the reactor, blowing them with oxygen-containing gas in the direction from the bottom up, followed by holding the treated feed in the reactor and unloading the finished product, characterized in that irradiation of the wet mixture is carried out by microwave rays, the loading of the irradiated raw materials in the reactor is carried out at a temperature of 70 80 ^o C, the raw materials are purged additionally in the transverse direction when standing removal of the exhaust gas, and the exposure of the raw materials is carried out for 60 70 h at 70 80 ^o C and after unloading the finished product is dried to a moisture content of 20 25%
2. A device for producing fertilizer from organic waste, including a raw material storage device, an irradiator, a device for supplying irradiated raw materials from the storage device to the reactor, a reactor with openings for loading the processed raw material and unloading the finished product, an oxygen-containing gas supply system to the raw material connected to injection units, a device for unloading the finished product, characterized in that as an irradiator in the interval between the drive and the reactor above the device for supplying raw materials installed microwave Bottom, oxygen-containing gas supply system from the bottom up is made in the form of two or more tiers of tubes with holes in the upper part, located at an equal distance from each other, and equipped with two or more rows of process tubes installed along the perimeter of the reactor and made with it in one piece holes on the inner side surface, in the lower part of the reactor, there is a drainage system in the form of technological pipes with holes in their lower part and located in two or more tiers along the entire width of the reactor and along first perimeter and at the reactor outlet is mounted drying assembly.

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