The invention relates to the field of processing agricultural waste arising from farming industry and human activity in agriculture. In particular, the invention relates to methods for recycling and processing manure, straw, sawdust and other waste and/or products potentially polluting the places where population dependent on agriculture live, thereby unfavorably affecting the health of inhabitants of small settlements, farms, shift teams and other groups of people working and/or living in substandard infrastructure areas away from technologically advanced centers. Moreover, the invention may be used for processing solid domestic waste.
It is common knowledge that agricultural waste has a serious environmental impact. A by-product of any agricultural specialization is a specific waste, which, even being per se environmentally compatible, is ecologically destructive when present in excessive amounts and excessively concentrated within a limited area. Such waste inter alia includes manure of livestock animals and litter thereof, straw of grain varieties, winemaking waste, logging debris etc. Often it is unprofitable to process the waste in specialized plants because of unreasonable transportation expenses and/or high processing costs, which would result in significant rise in the cost of the main product. As a rule, it is impossible to process the waste in situ whether because the producers are not motivated or because of lack of proper versatile equipment capable of change-over to process a certain waste during a corresponding season, e.g., to process straw in autumn, manure in winter etc.
In many countries, bioconversion of manure into methane is widely used, but this does not solve the problem of utilization in full, as after methane has been produced, a lot of material still is left in the tanks, which material should be processed into a useful product instead of being buried. At present, the most part of equipment is focused on processing waste of a particular type, and it is assumed that a waste processor is engaged in the business professionally and has sufficient volumes of the waste to process it profitably. Such volumes can be provided, e.g., by a large cattle-ranch or poultry farm, so that the processor can produce organic fertilizers from the manure.
The problem could be solved only by developing a sufficiently versatile technology and creating equipment for performing this technology capable of processing a sufficiently wide range of types of waste, e.g., the most of the agricultural waste.
A method for processing waste and an apparatus to implement the method shall meet a number of requirements, namely:
both the method and apparatus shall be versatile, capable of fulfilling a number of technological operations, such as drying, chopping, homogenizing, stirring, thermal treatment of various types (pyrolysis, gasification, incineration, calcinations, burning), wet treatment (including washing), chemical treatment (including reduction-oxidation, ion-exchange and substitution reactions, sorbent treatment, catalytic treatment etc.), and biological treatment (including composting) without any special redesign;
both the method and apparatus shall guarantee the environmental safety, in order that it would not be necessary to revitalize the environment afterwards by further methods and apparatuses, which often could be more expensive;
both the method and apparatus shall provide the economic efficiency of processing agricultural waste, which often can be provided only when the original waste is processed into marketable materials, e.g., fertilizers or compost feasible to be used in agriculture;
both the method and apparatus shall be easily realizable and shall not need a high-skilled staff for adjustment, readjustment, process tuning, maintenance, and repair.
There is known in the prior art a method for processing inflammable municipal waste by gasification and pyrolysis thereof to produce energy and gasification products described in the RU 2150045. According to this method, the waste to be processed is loaded into a gasification reactor of a shaft-furnace type, optionally with pieces of non-inflammable and non-fusible materials facilitating the gas permeability of the load. On the opposite end of the reactor, where the accumulation of processed solid products occurs, an oxygen-containing gasifying agent is fed, and the loaded waste is subject to gasification in the gasifying agent backflow. This method is sufficiently effective for solid waste processing and heat generation.
One of the major drawbacks of the method described in the RU 2150045 is its single-purpose function that is gasification of solid waste to produce thermal energy and gasification products. It is known that farming units do not need much thermal energy during warm season, and therefore the shaft furnace would either stand idle or burn the waste ineffectively.
Another major shortcoming of the method described in the RU 2150045 is that an expensive equipment and qualified staff are needed to implement this method. Consequently, such a method could be implemented only in cities where an all year-round processing waste would be cost-effective as municipal waste are available in sufficient amounts and a necessary staff (process managers, repairers, furnace operators etc.) could be easily hired.
There is also known in the prior art a method of bulk material thermal treatment implemented in a rotary furnace described in the RU 2027134, comprising the following steps: loading a bulk material into a drum-type furnace through an axial aperture having a smaller diameter on the input end of the furnace; rotating the furnace; feeding hot gases into the furnace on its output end to warm up the material within the furnace; and discharging the material through an axial aperture having a larger diameter on the output end of the furnace. This method is rather simple from the technological point of view and does not require a complex equipment and qualified staff.
One of the major drawbacks of the method described in the RU 2027134 is its single purpose—thermal treatment of bulk materials only.
Another major drawback of the method described in the RU 2027134 is its low capacity because of low spacing factor of the drum and low efficiency of the interaction between the material and a gas flow, as in fact only the surface layer of the material is capable of interacting with the gas flow.
For the method that is the subject of the present invention, a method of drying dough-like materials according to invention described in the RU 2100721, is selected as the closest technical solution in the prior art. The method comprises the following steps: generating a pouring-off filler layer consisting of an inert material not involved in processing the fed material chemically; blowing over the filler layer with a drying agent; feeding a material to be processed onto the pouring-off filler layer; conductive-convective drying of the material; and removal of dried material from a drying zone. This method is rather simple in terms of technology and does not require any complex equipment or qualified staff.
One of the major drawbacks of the method described in the RU 2100721 is its single purpose that is drying only dough-like materials.
Another major drawback of the method described in the RU 2100721 stems from the following. The more is the mass of the filler and the higher is its temperature, the more intensive is the drying process. However, a massive filler can disintegrate the drying material during such a drying process, which is inadmissible in case of drying, e.g., seed grains.
Besides, there is known in the prior art a rotating furnace for thermal treatment of bulk materials described in the RU 2027134 comprising walls on the input and output ends of a drum, the walls being made in the form of rings mounted coaxially with the drum, the height of the ring at the input end of the furnace being greater than the height of the ring at the output end of the furnace, which provides a gravity-flowing discharge of the furnace. Thereat, the ring at the output end of the furnace has additional holes in order to provide a complete discharge of the drum. This furnace is simple from the construction point of view and does not require a qualified staff for its operation.
One of major drawbacks of the apparatus described in the RU 2027134 is its single purpose that is thermal treatment of bulk materials.
Another major drawback of the apparatus described in the RU 2027134 is that it the material is caking during the treatment, which significantly limits the abilities of the apparatus even when used for drying or warming-up the material.
Besides, there is known in the prior art a furnace for thermal treatment of pulverous materials described in the SU Inventor's Certificate No. 857680 comprising ring diaphragms mounted within a heated rotating drums, the diaphragms having segment-like cut-outs in order to provide a uniform movement of the material being processed, a cut-out of each succeeding diaphragm being displaced with regard to the preceding one, which reduces the caking of the material due to its more uniform movement along the axis of the drum.
One of major drawbacks of the apparatus described in the SU 857680 is its single purpose that is warming-up bulk materials.
Moreover, it is impossible to entirely get rid of the caking of material, as the input material fed for the treatment may be non-homogeneous as to its structure, granularity, humidity, foreign inclusions etc.
As to the technical essence, the closest to the present invention is a drying assembly described in the RU 2130959 that is based on a self-discharging inclined rotating thermally insulated drum lengthwise divided into sections by annular partitions having passage openings of different diameters, said diameters increasing from an input charging unit to an output discharging unit.
To heat the ingoing material, the drum is filled with a hot inert filler, which successively overflows into each next section of the drum when its level reaches the level of a corresponding passage opening. Onto the hot filler, a slurry of utilizable material is fed, which, when dried, spills through a grid of the outer sidewall of the drum. This drying assembly is sufficiently simple and does not require a qualified staff for its operation.
One of the major drawbacks of the assembly described in the RU 2130959 is its single purpose that is drying a slurry of utilizable material in order to incinerate it in a special vertical furnace, said vertical furnace being used also to heat the inert filler necessary for the drying process. This drying assembly cannot work without such a vertical furnace.
Another major drawback of the assembly described in the RU 2130959 is that it is intended only for drying a slurry of utilizable material and cannot be used to utilize waste of other types, e.g., solid and gaseous waste.
Another major drawback of the assembly described in the RU 2130959 is that the performance of this assembly is determined by the number of bodies of the inert filler present in the drum at the same time, their capability of accumulating a certain amount of thermal energy, and the rate of circulation of the inert filler through the drum. As the number of bodies of the inert filler increases, the area of each passage opening decreases and simultaneously the average temperature within the drum decreases as well, which reduces the efficiency of drying. But increasing the area of each passage opening leads to the reduction of the number of bodies of the inert filler within the drum.
The method of invention has been developed as a versatile method providing processing various materials including agricultural waste. The method is free from the drawbacks of the prior art due to that the performed processes are consistent from the technical and technological points of view. The processes are performed using a standardized equipment and differ only in process conditions determining a degree of interaction between an original raw material and gaseous, liquid or solid materials present in the drum together with the original raw material.
In a versatile method for processing materials in a sectioned drum-type apparatus, the drum being divided into sections by partitions with passage openings therein, the method comprising the steps of: feeding an original raw material, bodies of an inert filler, and a gaseous agent into the apparatus; putting the apparatus in operation; and creating a gas flow through the apparatus; the above technical result is achieved due to that the method includes the operations of: filling the sections of the apparatus, partially or entirely, with the inert filler bodies up to a level higher than the level of the passage openings; forming an active zone on the way of the gas flow, where the original raw material is dropped and/or spilled with a predetermined rate and/or during a predetermined duration, thus providing its movement in between the surfaces of the inert filler bodies and/or through the bodies themselves; and controlling the duration and/or intensity of the interaction between the original raw material and the gaseous agent.
The above embodiment of the method provides a significant improvement, in particular, intensification, in comparison to the closest prior art, of the process of interaction between substances whether in the same or different states of matter (liquid-solid, liquid-gas, solid-gas) and a significant extension, in comparison to the closest prior art, of the nomenclature of available technological operations: in addition to drying and disintegration, the following operations can be performed:
thermal treatment of various materials, including drying, pyrolysis, gasification, incineration, calcinations, and burning,
wet treatment including washing,
chemical treatment including reduction-oxidation, ion-exchange and substitution reactions, sorbent treatment, and catalytic treatment,
mechanochemical treatment of materials, including granulation, disintegration, skinning etc.; and
biological treatment including composting.
Due to a predetermined rate and/or duration of dropping and/or spilling the original raw material, thereat providing its continuous movement in between the surfaces of the inert filler bodies and/or through the bodies themselves, the method of invention provides, basing on anticipatorily obtained empirical dependences, creating a versatile method for processing various agricultural waste as well as other waste including municipal waste and industrial wood residue. Thereat, when changing from waste of one type to another, it is enough to change parameters of the movement of the original raw material in between the surfaces of the inert filler bodies and/or through the bodies themselves in the active zone and to control duration and/or intensity of the interaction between the original raw material and the gaseous agent in order to change the technological process of the original raw material in a substantial way.
Basing on these processes, a farming enterprise would be able not only to effectively process agricultural waste, but also to provide it with thermal energy in amounts sufficient for warming both farming premises and living spaces, as well as to obtain useful products from the processed waste, such as fertilizers, compost etc., or to provide services (or meet in-house needs) such as disinfection of planting material, conditioned drying of final products, e.g., breadstuff.
For a real-time control of running processes operations, it seems promising to form the shape and/or sizes of the active zone by providing certain motion conditions of the drum and/or inclination of the drum axis, and/or choosing the shape and/or sizes and/or material of the inert filler bodies, and/or choosing the number of the inner sections of the drum, and/or choosing the number and/or area and/or shape and/or sizes and/or location of the passage openings made in the partitions between neighboring sections of the drum.
As for controlling the duration of stay and/or the rate of dropping and/or spilling of the original raw material in the active zone, it seems reasonable to perform it by changing the rotation speed of the continuously rotating drum, or reversing the direction of its rotation, or changing the duration of its rotation, or adjusting pauses between rotation phases in case of pulse rotation of the drum.
It is convenient to control the duration of stay and/or the velocity of movement of the original raw material in the active zone by choosing the shape and/or sizes and/or material of the inert filler bodies.
Advantageously, the duration of stay and/or the velocity of movement of the original raw material in the active zone may be controlled by choosing the number of inner sections of the drum, and/or choosing the number and/or area and/or shape and/or sizes and/or location of the passage openings made in the partitions between neighboring sections of the drum.
It seems promising to control the duration and/or intensity of the interaction between the original raw material and the gaseous agent by introducing an active component (or several active components) in solid, liquid or gaseous state into the drum, e.g., in the form of a catalyst or a sorbent, said active component(s) being applicable onto the inner and/or outer surface of the inert filler bodies, and/or interposeable in between the inert filler bodies and/or within the inert filler bodies.
It seems reasonable to control the duration and or intensity of the interaction between the original raw material and the gaseous agent in the active zone by choosing the number of the inner sections of the drum, and/or the number and/or area and/or shape and/or sizes and/or location of the passage openings made in the partitions between neighboring sections of the drum.
It is convenient to control the duration and/or intensity of the interaction between the original raw material and the gaseous agent in the active zone by choosing the head of the flow of the gaseous agent or the stream velocity of the gaseous agent or the flow rate of the gaseous agent.
Advantageously, the duration or the intensity of the interaction between the original raw material and gaseous agent in the active zone may be controlled by the degree of filling the drum and/or separate sections of the drum with the inert filler bodies, and/or by the permeability of the inert filler bodies themselves, and/or by choosing the sizes of the inert filler bodies, and/or by choosing the shape and/or material of the inert filler bodies.
It seems promising to control the duration and/or intensity of the interaction between the original raw material and gaseous agent by changing the rate of circulation of the inert filler through the drum.
In creating the present invention, the task was assigned to create a versatile apparatus providing processing various materials, particularly agricultural waste of various types in any physical state (solid, liquid or gaseous), and free from the above shortcomings of the prior art.
In a versatile apparatus for processing materials comprising a drum filled with bodies of an inert filler and lengthwise divided into sections by traverse partitions with passage openings therein, the apparatus being furnished with an input and an output devices and a drive mechanism to drive the drum, the above-identified task is completed by that each section of the drum is charged with the inert filler bodies up to a level not lower than that of the edges of the passage openings in the traverse partitions in any working position of the drum, and holes are made in the end surfaces or in the side surface of the drum intended for feeding and emission of the gaseous agent.
Such a structure of the apparatus allows to implement the method of invention due to creating an active zone on the way of passage of the gaseous agent within the drum, and provides an active interaction between the original raw material and gaseous agent in the active zone.
To control the intensity of the interaction between the original raw material and gaseous agent, it is convenient to furnish the apparatus with an adjustable drive mechanism for rotating the drum, which drive mechanism being capable of providing the following operations: changing the rotation velocity of the drum and/or reversing its rotation and/or an angular displacement of the drum at a predetermined angle and/or stopping down the drum for a certain time period in the course of its motion.
To increase the degree of involving the original raw material present in the drum in the interaction with the gaseous agent, it seems promising to furnish the sections of the drum with shake-off plates mounted on the traverse partitions and to install interspersing blades on the inner surface of the drum.
To change the modes of the active zone in an expeditious manner, it seems reasonable that the area of the passage openings in the traverse partitions of the drum sections be changeable, which could be provided, e.g., using a structure of a multi-lobe septum, as used in photographic cameras to change the light flux through the object lens.
To enlarge the technological possibilities of the apparatus, it seems advantageous that the inert filler bodies used for different processes and/or used in different sections of the drum be made of different shapes and/or sizes and/or materials.
To make the variety of materials to be processed greater and the possibilities of the apparatus broader, it seems convenient to make the inert filler bodies in the form of hollow capsules with a perforated surface, within which particles of an inert material (e.g., ceramic or glass beads) and/or an activated substance, e.g., silica gel, catalyst etc. can be retained, and/or the activated substance can be applied on the inner and/or outer surface of the capsules.
The embodiment of the method related to the invention will be described for the apparatus illustrated in
By controlling the velocity of rotation of the drum 1 and changing the direction of the rotation, such conditions of a permanent pouring of the original raw material in the active zone 30 are created that most of the time of the presence of the material to be processed in the drum 1 it is present in the active zone 30 where it is subject to an intensive interaction with the main gas stream flow 31, consequently, the process of drying the material accelerates. Interspersing blades 29 are provided in the apparatus which, when the original raw material is poured into the active zone 30, catch the material at the side surface of the drum 1 (see
Now the method of invention will be described as exemplified in
Now the method of invention will be described as exemplified in
For desiccating biogas, an apparatus shown in
To incinerate manure in order to obtain thermal energy, a two-drum apparatus shown in
Comparatively large enterprises, which produce so much waste that it is unreasonable to incinerate it all (as so much thermal energy is not needed), can use the technology of gasification of organic materials in order to obtain useful energy carrying products (pyrolytic resins) therefrom, which could be used, e.g., as a boiler fuel. To this end, an apparatus shown in
To clean air from ammonia, an apparatus shown in
Thus, the method and apparatus of invention allow creating a new technology of processing waste of different types, and a versatile apparatus configured to implement the method of invention in agricultural, wood-working and other enterprises where solid, liquid, or gaseous waste is produced which could be processed into marketable products.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/RU2009/000060 | 2/11/2009 | WO | 00 | 8/10/2011 |