CN116918511A - Straw carbonization returning device and method based on low-temperature squeezing - Google Patents

Abstract

A straw carbonization returning device and method based on low-temperature pressing comprises the following steps: squeezing the collected straws to obtain squeezed straws and nutrient solution separated from the straws; carbonizing the pressed straw to obtain a first mixture, and separating biochar from the first mixture; preparing the nutrient solution into a first solution; and mixing the biochar with the first solution to obtain a second mixture, and dropping the second mixture into soil. The straw is squeezed before carbonization, so that the energy consumption required by carbonizing the straw is reduced, the carbonization efficiency is improved, the straw treatment capacity of in-situ carbonization returning of the straw is effectively improved, and the straw carbonization returning machine is suitable for larger-scale carbonization returning operation; meanwhile, the straw nutrient solution pressed at low temperature is not affected by carbonization high temperature, and the straw nutrient solution and the biochar are buried in the soil together by collecting and utilizing the nutrient solution, so that the soil structure is further enriched, and the soil nutrient is improved.

Description

Straw carbonization returning device and method based on low-temperature squeezing

Technical Field

The application relates to the technical field of agricultural equipment, in particular to a straw carbonization returning device and method based on low-temperature pressing.

Background

Straw carbonization and returning can convert straw into biochar and add the biochar into soil, and is one of the most concise straw utilization modes. The biochar formed after straw carbonization can positively influence the physicochemical properties and nutrients of soil and the yield and quality of crops, so that the content of carbon elements in the soil is increased, the soil structure is improved, and the occurrence of plant diseases and insect pests can be reduced.

Two main modes of straw carbonization and returning to the field are adopted, one is that straw is bundled in the field and then transferred to a straw carbonization device for straw carbonization treatment to obtain biochar, and then the biochar is added into soil; the other is to collect the straws in the field by a movable integrated device, then directly carbonize the straws to obtain biochar, and add the biochar into the soil. The movable straw carbonization returning device can realize in-situ straw carbonization returning, so that the straw returning efficiency is effectively improved.

Patent CN213603107U discloses a self-propelled straw carbonization field returning machine, it carries the straw after smashing to the carbomorphism ware, the spiral of carbomorphism ware and the friction between the machine bore make the material intensive mixing, extrusion, heating, veneer, coking produce the tissue change, the structure of straw is destroyed, the material becomes the coking state that has flowing property, when the material is extruded the export, pressure changes the ordinary pressure from high pressure in the twinkling of an eye, change the normal atmospheric temperature in the twinkling of an eye from high temperature, cause moisture to evaporate out fast from the tissue structure, rethread ejection of compact cutter, cutting cooling is carbonization shaping, finally scatter on the ground, realize normal position carbonization field returning. Patent CN112063401A discloses a movable straw baking and carbonizing treatment in-situ returning method, wherein a carbonizing system divides the combustion of straw into two stages of primary combustion and volatile combustion so as to improve the combustion efficiency and further improve the carbonizing returning treatment efficiency.

It can be seen that the existing movable straw carbonization device and technology are used for directly carbonizing the collected straws. However, because the moisture content in the straw is 40-80%, a large amount of energy is required to be consumed for direct carbonization or baking and carbonization, and the treatment efficiency is low; meanwhile, partial nutrient substances which are contained in the straw and are favorable for soil structure transformation can be reacted in the high-temperature heating process and cannot be effectively utilized, and the carbonization and returning effect is reduced.

Disclosure of Invention

The application aims to provide a straw carbonization returning method based on low-temperature squeezing, which is characterized in that straws are squeezed before straw carbonization, so that nutrient solution in the straws is separated from the straws, and after the straws are carbonized, biochar obtained by carbonization is mixed with the nutrient solution obtained by separation and returned to soil, so that the carbonization energy consumption of the straws can be reduced, the carbonization efficiency can be improved, most of nutrient solution in the straws and the biochar can be mixed and then buried in the soil for co-fermentation, the soil structure is further enriched, and the soil nutrients are improved.

The above object of the present application is achieved by the following technical scheme:

a straw carbonization returning method based on low-temperature squeezing comprises the following steps:

squeezing the collected straws to obtain squeezed straws and nutrient solution separated from the straws;

carbonizing the pressed straw to obtain a first mixture, and separating biochar from the first mixture;

preparing the nutrient solution into a first solution;

and mixing the biochar with the first solution to obtain a second mixture, and dropping the second mixture into soil.

In the technical scheme, the straw carbonization returning method is characterized in that straws before carbonization are extruded and pressed in parallel, so that nutrient substances such as nitrogen salt, phosphor salt, magnesium salt, potassium salt, calcium salt and the like in the straws can be pressed out along with moisture to obtain nutrient solution. The straw losing most of the moisture can be carbonized more quickly in the subsequent carbonization process, and the nutrient solution and the nutrient substances contained in the nutrient solution avoid reaction, decomposition and volatilization in the carbonization high temperature. The separated nutrient solution is mixed with the biochar obtained after straw carbonization and then is buried in soil, and the biochar and the nutrient solution are fermented in the soil, so that the soil structure is enriched, the nutrients of the soil are improved, and the subsequent crop yield and quality are positively influenced.

In the technical scheme, the water content of the pressed straw is greatly reduced, the existing carbonization device can be adopted for directly carbonizing, and the drying device can be adopted for further drying and then carbonizing, so that the energy consumed by carbonizing and the carbonization efficiency are effectively improved due to the fact that the water content of the straw is pressed out in any mode.

In the technical scheme, solute and/or solvent can be added into nutrient solution obtained by squeezing straw according to requirements to obtain a first solution. In some embodiments, when less nutrient solution is expressed, a certain amount of water may be added for dilution to have a sufficient amount of the first solution mixed with the biochar. In one or more embodiments, the liquid byproduct of straw carbonization may be mixed with the nutrient solution to obtain the first solution, so as to further increase the content of the nutrient in the first solution, or a certain amount of water may be added to dilute the solution after the liquid byproduct and the nutrient solution are mixed.

In the technical scheme, the biochar and the first solution are mixed to obtain a second mixture for embedding into soil. In one or more preferred embodiments, the biochar is cooled during its exit from the carbonization device and delivery, and when cooled to a predetermined temperature, the biochar is mixed with the first solution to obtain a second mixture, avoiding the high temperature of the biochar affecting the nutrients in the first solution.

In the technical scheme, the straw is squeezed before carbonization, so that the energy consumption required by carbonizing the straw is reduced, the carbonization efficiency is improved, the straw treatment capacity of in-situ carbonization and returning of the straw is effectively improved, and the straw carbonization and returning device is suitable for larger-scale carbonization and returning operation; meanwhile, the straw nutrient solution pressed at low temperature is not affected by carbonization high temperature, and the straw nutrient solution and the biochar are buried in the soil together by collecting and utilizing the nutrient solution, so that the soil structure is further enriched, and the soil nutrient is improved.

Further, the straw carbonization returning method further comprises the following steps: and separating a liquid byproduct from the first mixture, mixing the liquid byproduct with the nutrient solution, and preparing a first solution.

In this embodiment, the liquid by-product separated from the first mixture is further utilized. The liquid byproducts of straw carbonization mainly comprise wood vinegar liquid, wood tar and the like. The research shows that the wood vinegar can not only effectively kill plant diseases and insect pests in soil, but also improve soil environment and promote microorganism propagation. Therefore, in order to effectively utilize the liquid by-product such as pyroligneous liquor, the liquid by-product is separated from the first mixture, and then added to the nutrient solution to be mixed to obtain a first solution, and then the first solution is mixed with the biochar. In addition, the liquid byproduct is added into the nutrient solution, so that the total volume of the first solution can be increased, and the mixing efficiency and the mixing uniformity of the first solution and the biochar are further improved by utilizing the premixing of the liquid byproduct and the nutrient solution.

As a preferred implementation mode of the straw carbonization returning method, the first solution is sprayed onto the biochar to form a second mixture in the process of dropping the biochar.

In the technical scheme, the first solution and the biochar are not fully mixed in a designated container to obtain a second mixture, but the first solution is sprayed onto the biochar to obtain the second mixture in the process that the biochar falls in the falling unit after the biochar is transmitted to the falling unit.

According to the technical scheme, after the straws are collected and carbonized in the straw carbonization returning process, the obtained biochar is directly discharged into soil, and in the biochar falling process, the first solution is sprayed on the surface of the biochar, so that the steps of fully mixing and separating the two are removed, and the mixing efficiency is remarkably improved.

In addition, the biochar can produce the hole on the surface in the cooling process, if soak biochar in first solution intensive mixing, the time of mixing will obviously increase, and first solution can enter into the inside of biochar along the hole, cause the volume of required first solution to increase by a wide margin, and because the total amount of squeezing the nutrient solution is unanimous, consequently the nutrient composition quantity that single biochar or biochar section correspond is showing and is reducing, and, stay in the nutrient substance in biochar hole be difficult to with soil contact in the short time, soil improvement efficiency, effect will appear certain degree and reduce.

According to the technical scheme, the first solution is sprayed on the biochar, so that the time of the steps of mixing and separating the first solution and the biochar can be saved, and the sprayed first solution is concentrated on the surface of the biochar and cannot enter the pores of the biochar, so that the first solution on the surface of the biochar can fully contact with the soil after falling into the soil along with the biochar, and the soil improvement effect and efficiency are improved.

Further, during the falling of the second mixture, an external force is applied to the second mixture, the external force serving to lengthen the falling time of the second mixture.

In the technical scheme, the second mixture falls onto soil under the action of gravity. During the falling of the second mixture, an external force is applied to the second mixture to extend the falling time thereof. In one or more embodiments, the second mixture may be sprayed from bottom to top by a gas flow such that the second mixture is subjected to upward buoyancy to slow down the fall time of the second mixture. In one or more embodiments, tangential wind may be formed in the blanking unit by applying lateral wind, so that the second mixture descends in a spiral shape, which also plays a role in delaying the falling time thereof.

In this technical scheme, the time of falling of extension second mixture is the contact time of extension biochar and first solution to make more first solution can cover to the surface of biochar, not only improve the nutrient solution loading capacity of single biochar, further improve soil improvement effect, moreover the biochar can be further cooled down at the whereabouts in-process, and then can reduce the time of leading biochar cooling process, for example reduce the total length of delivery segment, perhaps reduce the use amount of cooling air current in leading process, make straw carbomorphism still field's efficiency higher, the volume of corresponding straw carbomorphism still field device can set up compacter.

Further, the method also comprises the following steps: and collecting crushed stone, wherein the crushed stone moves together with the straw and is heated in the straw carbonization process, the crushed stone falls into the soil after being cooled to a preset temperature, and the temperature of the crushed stone falling into the soil is higher than that of the second mixture falling into the soil.

In the technical scheme, some broken stones can be collected while the straws are collected. Preferably, the crushed stone may be pebbles having a size of less than 1 cm. The collected broken stone moves together with the straw. For example, crushed stone enters the pressing unit together with the straw, is not affected while the straw is screw-pressed, and enters the carbonization unit along with the pressed straw. In the carbonization unit, the crushed stone is heated at a high temperature, and further chipping of a part of the crushed stone may occur.

The heated crushed stone passes through a blanking unit and falls into the soil together with the biochar. Under the action of external force with the same magnitude, such as air flow buoyancy, the broken stone is lower in influence of buoyancy due to higher density and fewer surface pores than the biochar, and tends to fall into the soil in a shorter time.

Because the falling time is shorter, the first solution sprayed on the crushed stone is less, and the cooling time is shorter, when the crushed stone falls into the soil, the first solution attached to the surface of the crushed stone is less, and the temperature of the crushed stone is obviously higher than that of the biochar.

The rubble with higher temperature can kill plant diseases and insect pests in the soil to a certain extent, and meanwhile, the rubble with higher temperature can release trace mineral substances, so that the mineral substance content in biochar and the soil is effectively improved, and the soil structure is further improved.

Further, in the process of the falling of the biochar, cooling water is sprayed on the biochar. Spraying cooling water onto the biochar can lower the temperature of the biochar faster, and avoid affecting the nutritional components of the nutrient solution. Meanwhile, sprayed cooling water can also play a role in dust fall, so that some carbonized biochar and sand with smaller volumes can fall into soil more quickly, the accumulation of sand in a blanking unit is reduced, and the mixing effect of the first solution and the biochar is further improved.

The application further aims to provide a movable straw in-situ carbonization returning device, which is used for squeezing straws to squeeze nutrient substances in the straws together with moisture to obtain nutrient solution, carbonizing the squeezed straws by using a carbonization unit to obtain biochar, mixing the biochar with the nutrient solution and adding the biochar into soil, so that the purposes of improving carbonization efficiency, reducing carbonization energy consumption and retaining the nutrient solution to improve physical and chemical properties and nutrients of the soil are achieved.

The above object of the present application is achieved by the following technical scheme:

the straw carbonization returning device based on low-temperature squeezing comprises a frame, a stubble cleaning unit, a collecting unit, an operating unit and a traveling unit, wherein the stubble cleaning unit, the collecting unit, the operating unit and the traveling unit are arranged on the frame, and the straw carbonization returning device further comprises:

the squeezing unit is used for squeezing the straws collected by the collecting unit to obtain squeezed straws and nutrient solution separated from the straws;

a carbonization unit for carbonizing the pressed straw to obtain a first mixture;

a first separation unit for separating biochar and liquid byproducts from the first mixture;

a mixing unit for mixing the liquid by-product and the nutrient solution to obtain a first solution;

and the discharging unit is used for mixing the biochar with the first solution in the falling process to obtain a second mixture, and the second mixture falls into soil through an opening at the bottom of the discharging unit.

In the technical scheme, the straw carbonization returning device comprises a frame, a stubble cleaning unit for rotary tillage stubble cleaning and weed removal, a collecting unit for collecting straws, broken stones, sand stones and residual membranes, a traveling unit for moving the straw carbonization returning device, an operating unit for controlling the straw carbonization returning device and a carbonization unit for carbonizing the straws, wherein the stubble cleaning unit is the same with the prior art. The units can all adopt the existing equipment.

Unlike available technology, the straw carbonizing and returning apparatus includes also squeezing unit, mixing unit and discharging unit.

Specifically, the squeezing unit is positioned before the carbonization unit and after the collection unit and is used for squeezing and squeezing the collected straws so as to squeeze the straws to obtain the nutrient solution containing nutrient substances such as inorganic salts, organic matters and the like. The pressed straw is conveyed to a carbonization unit for further carbonization to obtain a first mixture containing combustible gas, liquid byproducts and biochar; and the pressed nutrient solution is collected and delivered to the mixing unit.

The first separation unit may employ a single stage or multi-stage separation device, for example, a gas separation device may be used to separate the combustible gas from the first mixture and to recycle the combustible gas to the carbonization unit; the biochar and liquid byproducts can be separated using a solid-liquid separation device. After separation, the biochar is sent to a blanking unit and the liquid by-product is sent to a mixing unit.

In the mixing unit, the liquid by-product is thoroughly mixed with the collected nutrient solution. Of course, the liquid by-products may be cooled prior to mixing in order to avoid the high temperature of the liquid by-products adversely affecting the nutrient solution. Other auxiliary agents may or may not be added to the first solution obtained by mixing the liquid by-product with the nutrient solution. The homogeneously mixed first solution is preferably transported to the blanking unit by means of a carrier gas, such as air.

Biochar falls into the unloading unit through the discharge gate of conveyor screw to drop under the effect of gravity. In the falling process, the first solution is sprayed on the biochar in a gas spray mode, the biochar is mixed with the first solution to obtain a second mixture, and finally the second mixture falls into soil through an opening at the bottom of the blanking unit.

By the device, the straw carbonization returning device can squeeze and carbonize the straw while collecting the straw in the moving process, and the straw is fully squeezed before carbonization to lose a large amount of moisture, so that the straw can be carbonized with lower energy consumption, the treatment time is shorter, and the device is suitable for larger-scale straw carbonization; in addition, nutrient solution and liquid byproducts in the straw are well collected and finally are buried in soil together with biochar for co-fermentation, so that the soil improvement effect is effectively improved.

Further, the press unit comprises a shell, a filter plate is arranged in the shell, the filter plate divides the interior of the shell into a press cavity and a collection cavity positioned below the press cavity, a conical screw is arranged in the press cavity, the diameter of the conical screw gradually increases from a feed inlet to the direction of a straw discharge outlet, the feed inlet is communicated with the collection unit, the straw discharge outlet is communicated with the carbonization unit, and the collection cavity is communicated with the mixing unit.

In this technical scheme, be provided with the filter in the unit of squeezing, the top of filter is the pressure chamber of cylinder structure, presses the intracavity and is provided with the conical screw, and the diameter of conical screw increases gradually from the feed inlet to discharge gate direction to make the space between two adjacent blades reduce gradually from the feed inlet to discharge gate direction. When the straws enter the pressing cavity from the feed inlet, the interval between adjacent straws is larger, and the extrusion force between the straws and the extrusion force of the conical screw and the inner wall of the pressing cavity on the straws are minimum; in the process of moving the straws to the straw discharge port, the extrusion force between the straws and the extrusion force of the straws on the inner walls of the conical screw rods, the blades and the squeezing cavity are gradually increased due to the gradual reduction of the space, and the maximum extrusion force is reached at the straw discharge port.

In the process of rotating and advancing along with the conical screw, the extrusion force applied to the straw is continuously increased, so that the nutrient substances contained in the straw are extruded along with the movement of water. The collecting cavity is arranged below the filter plate, and nutrient solution extruded from the straw flows into the collecting cavity through the filter plate to be collected, and finally flows into the mixing unit to be mixed with the liquid byproducts.

In the technical scheme, the squeezing unit adopts the structure of the conical screw, gradually increased extrusion force can be applied to the straws in the process of conveying the straws, so that the conveying and squeezing efficiency is improved, and meanwhile, the way of squeezing the straws at low temperature can not cause the reaction and loss of nutrient components in the nutrient solution, so that the improvement effect of soil is improved.

Further, the blanking unit comprises a cylinder body, a spray hole and a spray head are arranged on the cylinder body and located below the spray hole, the spray hole is used for spraying gas into the cylinder body, the gas is used for applying external force to the falling second mixture to prolong the falling time of the second mixture, and the spray head is used for spraying the first solution onto the second mixture in the cylinder body.

In the technical scheme, the blanking unit comprises a cylinder with a downward opening, the gas sprayed out of the spray hole arranged on the cylinder impacts the falling second mixture, and the external force applied to the cylinder can be vertical upward, transverse tangential wind or oblique upward airflow. In either form, the fall time of the second mixture is prolonged under the influence of external force.

In the technical scheme, the spray head arranged below the spray hole is communicated with the mixing unit, the carrier gas presses the first solution formed in the mixing unit into the spray head, the first solution is sprayed into the cylinder body through the spray head, the first solution is contacted with the second mixture with the prolonged falling time, and the content of the first solution on the surface of the second mixture is improved. Preferably, the outlet end of the spray head is provided with a porous structure so that the first solution is sprayed in the form of a spray into the blanking structure.

Further, a fan is communicated with the cylinder body, the fan is communicated with the spray hole and the mixing unit, and the mixing unit is communicated with the spray head. Specifically, the fan is communicated with the top of the cylinder, the spray hole and the mixing unit. The air flow quantity delivered to the spray holes and the mixing unit can be controlled by adjusting the valve of each pipeline, so that the air flow quantity sprayed out of the spray holes and the spray heads can be adjusted. The gas in the cylinder body is discharged from the top of the cylinder body and then reenters the cylinder body through the spray hole and the spray head, so that circulating air is formed.

Compared with the prior art, the application has the following advantages and beneficial effects:

1. the straw is squeezed before carbonization, so that the energy consumption required by carbonizing the straw is reduced, the carbonization efficiency is improved, the straw treatment capacity of in-situ carbonization returning of the straw is effectively improved, and the straw carbonization returning machine is suitable for larger-scale carbonization returning operation; meanwhile, the straw nutrient solution pressed at low temperature is not affected by carbonization high temperature, and the straw nutrient solution and the biochar are buried in the soil together by collecting and utilizing the nutrient solution, so that the soil structure is further enriched, and the soil nutrient is improved;

2. according to the application, the first solution is sprayed on the biochar, so that the time of the steps of mixing and separating the first solution and the biochar can be saved, and the sprayed first solution is mostly concentrated on the surface of the biochar and cannot enter the pores of the biochar, so that the first solution on the surface of the biochar can fully contact with the soil after falling into the soil along with the biochar, and the soil improvement effect and efficiency are improved;

3. according to the application, the contact time of the biochar and the first solution is prolonged, so that more first solution can be covered on the surface of the biochar, the nutrient solution loading capacity of single biochar is improved, the soil improvement effect is further improved, the biochar can be further cooled in the falling process, the time of a pre-arranged biochar cooling process can be further reduced, and the straw carbonization returning efficiency is higher;

4. according to the application, liquid byproducts such as wood vinegar and the like are effectively utilized, after the wood vinegar is separated from the first mixture, the liquid byproducts are added into the nutrient solution to be mixed to obtain the first solution, and then the first solution is mixed with the biochar, so that the soil environment is further improved, and the microorganism reproduction is promoted;

5. according to the application, the crushed stones with higher temperature are utilized to kill plant diseases and insect pests in the soil, and meanwhile, the crushed stones with higher temperature can release trace mineral substances, so that the mineral substance content in biochar and the soil is effectively improved, and the soil structure is improved;

6. the squeezing unit of the straw carbonization and returning device adopts a conical screw structure, can apply gradually increased squeezing force to the straw in the straw conveying process, improves the conveying and squeezing efficiency, and meanwhile, the way of squeezing the straw at low temperature can not cause the reaction and loss of nutrient components in nutrient solution, thereby being beneficial to improving the soil improvement effect.

Drawings

The accompanying drawings, which are included to provide a further understanding of embodiments of the application and are incorporated in and constitute a part of this specification, illustrate embodiments of the application and together with the description serve to explain the principles of the application. In the drawings:

FIG. 1 is a block flow diagram of a method for returning straw to field during carbonization in an embodiment of the application;

fig. 2 is a schematic structural diagram of a straw carbonization and returning device in an embodiment of the present application;

FIG. 3 is a schematic top view of a first conveying unit according to an embodiment of the present application;

FIG. 4 is a schematic diagram showing a structure of a pressing unit according to an embodiment of the present application;

FIG. 5 is a schematic diagram of a blanking unit according to an embodiment of the present application;

fig. 6 is a schematic diagram of a cross section of a blanking unit cylinder with a tangential wind layer formed therein according to an embodiment of the present application.

In the drawings, the reference numerals and corresponding part names:

1-rack, 2-stubble cleaning unit, 3-collecting unit, 4-first conveying unit, 41-screening plate, 5-second separating unit, 6-second conveying unit, 7-squeezing unit, 71-shell, 72-conical screw, 73-filter plate, 74-collecting cavity, 75-guide plate, 76-blade, 77-feed inlet, 78-straw discharge outlet, 79-nutrient solution discharge outlet, 710-first squeezing area, 711-second squeezing area, 712-first pipe, 8-carbonization unit, 9-blanking unit, 91-cylinder, 92-conveying screw, 93-spray orifice, 931-first air inlet pipe, 94-second air inlet pipe, 95-spray head, 96-water tank, 97-spray pipe, 98-spray head, 99-filter screen, 910-third pipe, 911-fan, 10-first separating unit, 101-second pipe, 11-mixing unit, 12-earthing unit, 13-walking unit, 14-handling unit, 15-tangential circular wind layer.

Detailed Description

For the purpose of making apparent the objects, technical solutions and advantages of the present application, the present application will be further described in detail with reference to the following examples and the accompanying drawings, wherein the exemplary embodiments of the present application and the descriptions thereof are for illustrating the present application only and are not to be construed as limiting the present application.

In the description of the present application, it should be understood that the terms "front", "rear", "left", "right", "upper", "lower", "vertical", "horizontal", "high", "low", "inner", "outer", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are merely for convenience in describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the scope of the present application.

Example 1:

the straw carbonization returning method based on low-temperature pressing shown in fig. 1 comprises the following steps:

squeezing the collected straws to obtain squeezed straws and nutrient solution separated from the straws;

carbonizing the pressed straw to obtain a first mixture, and separating biochar from the first mixture;

preparing the nutrient solution into a first solution;

and mixing the biochar with the first solution to obtain a second mixture, and dropping the second mixture into soil.

In this embodiment, the combustible gas, the liquid byproduct and the biochar contained in the first mixture generated by carbonizing the straw can be classified by a single-stage or multi-stage separation device. For combustible gas, the combustible gas can be reintroduced into the carbonization unit through a gas pipeline for recycling; the liquid byproducts can be collected independently, and in one or more preferred embodiments, the obtained liquid byproducts can be mixed with nutrient solution and biochar and then added into soil; for biochar, a cutting device may be arranged at the outlet end of the conveying screw between the charring unit and the first separating unit, between the first separating unit and the conveying screw, for cutting the biochar into segments of the biochar with substantially uniform or non-uniform size, and finally falling into soil, preferably cutting the biochar into segments with substantially uniform size.

In some embodiments, when less nutrient solution is expressed, a certain amount of water may be added for dilution to have a sufficient amount of the first solution mixed with the biochar. In one or more embodiments, the liquid byproduct of straw carbonization may be mixed with the nutrient solution to obtain the first solution, so as to further increase the content of the nutrient in the first solution, or a certain amount of water may be added to dilute the solution after the liquid byproduct and the nutrient solution are mixed.

In one or more preferred embodiments, the biochar is cooled during its exit from the carbonization device, during transport, and when cooled to a predetermined temperature, for example below 80 ℃, the biochar is mixed with the first solution to obtain a second mixture, avoiding the high temperature of the biochar affecting the nutrients in the first solution. In some embodiments, the biochar and the first solution are fully mixed to obtain a second mixture, and then the second mixture is dropped into the soil, or the biochar is continuously contacted with the first solution in the dropping process and mixed to obtain a second mixture with continuously increased weight, and finally the second mixture is dropped into the soil.

Example 2:

on the basis of the embodiment 1, the method further comprises the following steps: and separating a liquid byproduct from the first mixture, mixing the liquid byproduct with the nutrient solution, and preparing a first solution.

In some embodiments, the liquid by-product is cooled and then contacted with the nutrient solution, so that the influence of the high temperature of the liquid by-product on the nutrient components in the nutrient solution is avoided. In one or more embodiments, the nutrient solution and liquid by-products may also not be mixed and sprayed separately onto the surface of the biochar, but the uniformity and efficiency of mixing may be somewhat poor.

In a partially preferred embodiment, the first solution is sprayed onto the biochar during its fall to form a second mixture. By spraying the first solution on the biochar, the time of the steps of mixing and separating the first solution and the biochar can be saved, and the sprayed first solution is mostly concentrated on the surface of the biochar and cannot enter the pores of the biochar, so that the first solution on the surface of the biochar can fully contact with the soil after falling into the soil along with the biochar, and the soil improvement effect and efficiency are improved

In a partially preferred embodiment, an external force is applied to the second mixture during its fall, said external force serving to extend the fall time of the second mixture. In one or more embodiments, the second mixture may be sprayed from bottom to top by a gas flow such that the second mixture is subjected to upward buoyancy to slow down the fall time of the second mixture. In one or more embodiments, tangential wind may be formed in the blanking unit by applying lateral wind, so that the second mixture descends in a spiral shape, which also plays a role in delaying the falling time thereof.

In a partially preferred embodiment, the method further comprises the steps of: and collecting crushed stone, wherein the crushed stone moves together with the straw and is heated in the straw carbonization process, the crushed stone falls into the soil after being cooled to a preset temperature, and the temperature of the crushed stone falling into the soil is higher than that of the second mixture falling into the soil. The rubble with higher temperature can kill plant diseases and insect pests in the soil to a certain extent, and meanwhile, the rubble with higher temperature can release trace mineral substances, so that the mineral substance content in biochar and the soil is effectively improved, and the soil structure is further improved. In one or more embodiments, the predetermined temperature of the crushed stone may be 60 to 120 ℃. In some embodiments, the crushed stone is pebbles of a size less than 1 cm.

In one or more embodiments, cooling water is sprayed onto the biochar during the biochar fall. The spray cooling water can reduce the temperature of the biochar more quickly, and the influence on the nutrient components of the nutrient solution is avoided. Meanwhile, sprayed cooling water can also play a role in dust fall, so that the accumulation of sand and dust in the blanking unit is reduced, and the mixing effect of the first solution and the biochar is further improved.

Example 3:

the straw carbonization returning device based on low-temperature squeezing as shown in fig. 2 to 6 comprises a frame 1, a stubble cleaning unit 2, a collecting unit 3, a manipulating unit 14 and a walking unit 13 which are arranged on the frame 1, and further comprises:

a squeezing unit 7 for squeezing the straw collected by the collecting unit 3 to obtain the squeezed straw and the nutrient solution separated from the straw;

a carbonization unit 8 for carbonizing the pressed straw to obtain a first mixture;

a first separation unit 10 for separating biochar and liquid byproducts from the first mixture;

a mixing unit 11 for mixing the liquid by-product and the nutrient solution to obtain a first solution;

and the blanking unit 9 is used for mixing the biochar with the first solution in the falling process to obtain a second mixture, and the second mixture falls into soil through an opening at the bottom of the blanking unit 9.

The straw carbonization returning device can squeeze and carbonize the straw while collecting the straw in the moving process, and the straw is fully squeezed before carbonization to lose a large amount of moisture, so that the straw can be carbonized with lower energy consumption, the treatment time is shorter, and the straw carbonization returning device is suitable for larger-scale straw carbonization; in addition, nutrient solution and liquid byproducts in the straw are well collected and finally are buried in soil together with biochar for co-fermentation, so that the soil improvement effect is effectively improved.

In a part of preferred embodiments, a second separation unit 5 is further arranged between the collecting unit and the squeezing unit, and the second separation unit is used for separating the collected soil, residual film and straw, so as to perform the function of pretreatment on the straw. In one or more embodiments, a first conveying unit 4, such as a conveyor belt, is further disposed between the second separating unit and the collecting unit, so as to convey the collected straw, residual film, soil, crushed stone, etc. into the second separating unit for separation. In one or more embodiments, as shown in fig. 3, the conveyor belt is further provided with screening plates 41 for discharging larger-sized crushed stone from both sides of the conveyor belt, while smaller-sized crushed stone is caught on the screening plates and brought into the second separation unit. In a preferred embodiment, crushed stone obtained by screening through the screening plate moves to the carbonization unit together with the straw, and finally falls into soil after being cooled.

In some embodiments, the straw carbonization-returning device is further provided with a soil covering unit 12, which may be disposed after the discharging unit, and after the second mixture falls into a trench previously opened in the soil, the soil covering unit pushes the surrounding soil to bury the second mixture.

Example 4:

on the basis of the above embodiment, as shown in fig. 4, the pressing unit 7 includes a housing 71, a filter plate 73 is disposed in the housing 71, the filter plate 73 divides the interior of the housing 71 into a pressing cavity and a collecting cavity 74 located below the pressing cavity, a conical screw 72 is disposed in the pressing cavity, the diameter of the conical screw 72 gradually increases from a feed port 77 to a straw discharge port 78, the feed port 77 is communicated to the collecting unit 3, the straw discharge port 78 is communicated to the carbonization unit 8, and the collecting cavity 74 is communicated to the mixing unit 11.

In this embodiment, the diameter of the conical screw gradually increases from the feed inlet to the discharge outlet, so that the space between two adjacent blades gradually decreases from the feed inlet to the discharge outlet. For example, as shown in fig. 4, the space of the first press area 710 is larger than the space of the second press area 711.

In one or more embodiments, the pitch between the blades of the conical screw may also be set to decrease gradually in the direction from the inlet to the outlet.

In one or more embodiments, a guide plate 75 is provided within the collection chamber to guide the nutrient solution within the collection chamber to the nutrient solution discharge outlet.

In this embodiment, squeeze the unit and adopt the structure of conical screw, can exert the extrusion force of crescent to straw at the in-process of transmission straw, improve transmission, squeeze efficiency, simultaneously, the mode of squeezing the straw at a low temperature can not cause nutrient composition reaction, the loss in the nutrient solution, is favorable to improving soil improvement effect.

Example 5:

on the basis of the above embodiment, as shown in fig. 5, the blanking unit 9 includes a cylinder 91, on which a spray hole 93 is provided, and a spray head 95 located below the spray hole 93, the spray hole 93 is used for spraying gas into the cylinder 91, the gas is used for applying external force to the falling second mixture to prolong the falling time of the second mixture, and the spray head 95 is used for spraying the first solution onto the second mixture in the cylinder 91.

In one or more embodiments, the cylinder is further provided with a conveying screw, the feeding end of the conveying screw is communicated with the biochar discharging end of the first separation unit, the discharging end of the conveying screw is located in the cylinder, and the discharging end of the conveying screw can be set according to the air flow type formed in the cylinder by the spray holes, for example, for forming transverse circle-cutting air as shown in fig. 6 by the spray holes, the discharging end of the conveying screw can be close to the inner wall of the cylinder, for forming vertical upward air flow by the spray holes, and the discharging end of the conveying screw can be close to the center of the cylinder.

In one or more embodiments, the top of the cylinder is provided with a water tank, the water tank is connected with a plurality of spray heads positioned in the cylinder through spray pipes, and the spray heads are used for spraying cooling water in the water tank into the cylinder so as to cool substances such as biochar, second mixture, crushed stone and the like in the cylinder.

In one or more embodiments, the nozzles may be disposed on different sections of the barrel, with the nozzle being located below the lowest nozzle.

In a part of the preferred embodiment, a fan 911 is connected to the cylinder 91, the fan 911 is connected to the spraying hole 93 and the mixing unit 11, and the mixing unit 11 is connected to the spraying head 95. The gas in the cylinder body is discharged from the top of the cylinder body and then reenters the cylinder body through the spray hole and the spray head, so that circulating air is formed. In some embodiments, the jet hole and the mixing unit may be separately connected to an additional induced draft fan to regulate the airflow in the cylinder.

The use of "first", "second", etc. (e.g., first conveying unit, second conveying unit, first press zone, second press zone, etc.) in the present application is merely for clarity of description to distinguish the corresponding components, and is not intended to limit any order or emphasize importance, etc. The term "connected" used in the present application may be directly connected or indirectly connected via other members unless otherwise specified.

The foregoing description of the embodiments has been provided for the purpose of illustrating the general principles of the application, and is not meant to limit the scope of the application, but to limit the application to the particular embodiments, and any modifications, equivalents, improvements, etc. that fall within the spirit and principles of the application are intended to be included within the scope of the application.

Claims (10)

1. The straw carbonization returning method based on low-temperature squeezing is characterized by comprising the following steps of:

squeezing the collected straws to obtain squeezed straws and nutrient solution separated from the straws;

carbonizing the pressed straw to obtain a first mixture, and separating biochar from the first mixture;

preparing the nutrient solution into a first solution;

and mixing the biochar with the first solution to obtain a second mixture, and dropping the second mixture into soil.

2. The straw carbonization returning method based on low-temperature pressing according to claim 1, wherein a liquid byproduct is separated from the first mixture, and the liquid byproduct is mixed with the nutrient solution to prepare a first solution.

3. The method for returning straw carbonized to the field based on low-temperature pressing according to claim 1 or 2, wherein the first solution is sprayed onto the biochar to form a second mixture in the process of dropping the biochar.

4. A method for charring straw and returning to field based on low temperature pressing as recited in claim 3, wherein an external force is applied to the second mixture during the falling process of the second mixture, and the external force is used for prolonging the falling time of the second mixture.

5. The straw carbonization returning method based on low-temperature pressing as claimed in claim 3, further comprising the following steps: and collecting crushed stone, wherein the crushed stone moves together with the straw and is heated in the straw carbonization process, the crushed stone falls into the soil after being cooled to a preset temperature, and the temperature of the crushed stone falling into the soil is higher than that of the second mixture falling into the soil.

6. The straw carbonization returning method based on low-temperature pressing as claimed in claim 3, wherein cooling water is sprayed onto the biochar in the process of falling the biochar.

7. The utility model provides a straw carbomorphism still field device based on low temperature presses, includes frame (1), and install in stubble-cleaning unit (2), collection unit (3), control unit (14) and walking unit (13) on frame (1), its characterized in that still includes:

the squeezing unit (7) is used for squeezing the straws collected by the collecting unit (3) to obtain squeezed straws and nutrient solution separated from the straws;

a carbonization unit (8) for carbonizing the pressed straw to obtain a first mixture;

a first separation unit (10) for separating biochar and liquid byproducts from the first mixture;

a mixing unit (11) for mixing the liquid by-product and the nutrient solution to obtain a first solution;

the blanking unit (9) is used for mixing the biochar with the first solution in the falling process to obtain a second mixture, and the second mixture falls into soil through an opening at the bottom of the blanking unit (9).

8. The straw carbonization field returning device based on low-temperature squeezing according to claim 7, wherein the squeezing unit (7) comprises a shell (71), a filter plate (73) is arranged in the shell (71), the filter plate (73) divides the interior of the shell (71) into a squeezing cavity and a collecting cavity (74) arranged below the squeezing cavity, a conical screw (72) is arranged in the squeezing cavity, the diameter of the conical screw (72) gradually increases from a feeding hole (77) to a straw discharging hole (78), the feeding hole (77) is communicated to the collecting unit (3), the straw discharging hole (78) is communicated to the carbonization unit (8), and the collecting cavity (74) is communicated to the mixing unit (11).

9. The straw carbonization and returning device based on low-temperature squeezing according to claim 7, wherein the blanking unit (9) comprises a barrel (91), a spray hole (93) and a spray head (95) positioned below the spray hole (93) are arranged on the barrel (91), the spray hole (93) is used for spraying gas into the barrel (91), the gas is used for applying external force to the falling second mixture to prolong the falling time of the second mixture, and the spray head (95) is used for spraying the first solution onto the second mixture in the barrel (91).

10. The straw carbonization and returning device based on low-temperature squeezing according to claim 9, wherein a fan (911) is communicated with the cylinder (91), the fan (911) is communicated with the spray hole (93) and the mixing unit (11), and the mixing unit (11) is communicated with the spray head (95).