A treatment device and preparation method for preparing carbon source from kitchen waste

Abstract

The present invention relates to the technical field of kitchen waste treatment, and particularly relates to a treatment device and a preparation method for preparing carbon source from kitchen waste. The treatment device includes a tank body, a double-circulation stirring device, an acid washing tower, an oil and slag removal device, and a slurry storage tank. The double-circulation stirring device includes a first circulation coil pipe and a second circulation coil pipe arranged in the tank body, and both the first circulation coil pipe and the second circulation coil pipe can aerate and stir the slurry; the air inlet of the acid washing tower is communicated with the tank body, and the air outlet of the acid washing tower is communicated with the first circulation coil pipe and the second circulation coil pipe; the oil and slag removal device is communicated with the tank body, and the oil and slag removal device can pump out the floating oil at the top of the slurry and the sediment at the bottom of the slurry from the tank body; the slurry storage tank is communicated with the tank body. The treatment device integrates functions of ammonia nitrogen absorption, oil and slag removal, and hydrolysis, greatly reducing the number of devices, and the various mechanisms can cooperate with each other, with high operation efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of kitchen waste treatment, and particularly relates to a treatment device and a preparation method for preparing carbon source from kitchen waste. Background Art

[0002] Kitchen waste, also known as food waste, is an important part of municipal solid waste, accounting for about 37% - 62% of the total output of municipal waste. At present, most of the research directions for kitchen waste treatment focus on anaerobic fermentation to produce methane, fertilizer production, and feed production. However, these technologies have problems such as high parameter control requirements and difficulties in selling products, and it is difficult to form a synergy with other environmental protection facilities. For example, when coordinating the treatment of kitchen waste with a sewage treatment plant or a waste treatment plant, how to achieve the harmless and resourceful utilization of kitchen waste is an urgent problem to be solved.

[0003] Research has found that the hydrolysis acidification liquid of kitchen waste contains more small molecule organic acids such as lactic acid and volatile fatty acids, which have excellent denitrification potential. Therefore, using kitchen waste to prepare a new type of carbon source has also become a new research direction. Using kitchen waste to prepare carbon source can not only reduce the amount of kitchen waste and relieve the pressure of incineration treatment of backend equipment, but also become a new way to achieve resource utilization, and the prepared carbon source can be used in sewage treatment plants or waste treatment plants. However, there are two major problems that need to be solved urgently in the preparation of carbon source from kitchen waste at present. One is that kitchen waste contains a large amount of unfavorable factors such as grease and ammonia nitrogen, and the efficiency of hydrolyzing and acidifying to convert organic matter that can be utilized by microorganisms is low, resulting in low quality of the prepared carbon source. The other is that most of the current technologies for preparing carbon source from kitchen waste are combinations of process technologies such as degreasing, hydrolyzing and acidifying, and denitrifying the slurry after pretreatment, but the process flow is relatively complex, the required equipment is more, and the efficiency of preparing carbon source is low. Summary of the Invention

[0004] (1) Technical Problems to be Solved

[0005] In view of the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides a treatment device and a preparation method for preparing carbon source from kitchen waste, which solve the technical problem that the low efficiency of the hydrolysis reaction of kitchen waste leads to low quality of the prepared carbon source.

[0006] (2) Technical Solutions

[0007] In order to achieve the above object, the treatment device for preparing carbon source from kitchen waste of the present invention includes:

[0008] A tank body;

[0009] Double - circulation stirring device, the double - circulation stirring device includes a first circulation coil pipe and a second circulation coil pipe arranged inside the tank body, the first circulation coil pipe is arranged above the second circulation coil pipe; both the first circulation coil pipe and the second circulation coil pipe can aerate and stir the slurry inside the tank body; the second circulation coil pipe is also communicated with the slurry storage tank;

[0010] Pickling tower, the air inlet of the pickling tower is communicated with the tank body, and the air outlet of the pickling tower is communicated with the first circulation coil pipe and the second circulation coil pipe;

[0011] Oil - and - slag removal device, the oil - and - slag removal device is communicated with the tank body, and the oil - and - slag removal device can pump out the floating oil at the top of the slurry and the sediment at the bottom of the slurry from the tank body;

[0012] Slurry storage tank, the slurry storage tank is communicated with the tank body; the slurry storage tank can adjust the liquid level height of the slurry.

[0013] Optionally, a plurality of first circulation nozzles are arranged on the first circulation coil pipe, and the plurality of first circulation nozzles are arranged to incline upwards;

[0014] A plurality of second circulation nozzles are arranged on the second circulation coil pipe, and the nozzles on the second circulation coil pipe are arranged to incline downwards.

[0015] Optionally, the first circulation nozzle includes a housing and a gravity check valve;

[0016] The housing is communicated with the first circulation coil pipe;

[0017] The gravity check valve is built in the housing, and a plurality of exhaust holes are opened on the gravity check valve;

[0018] A diversion groove is opened in the housing, and the diversion groove is arranged between the gravity check valve and the first circulation coil pipe.

[0019] Optionally, the oil - and - slag removal device includes an oil - discharging mechanism and a sand - discharging mechanism;

[0020] The oil - discharging mechanism is communicated with the upper end of the slurry;

[0021] The sand - discharging mechanism is communicated with the lower end of the slurry.

[0022] Optionally, the oil - discharging mechanism includes an overflow groove and a scum box;

[0023] The overflow groove is opened on the inner wall of the tank body, and the overflow groove is communicated with the scum box located outside the tank body.

[0024] Optionally, the sand discharging mechanism includes a sand discharging pipe and a sand discharging pump;

[0025] One end of the sand discharging pipe is arranged at the bottom of the inner wall of the tank body, and the other end is communicated with the sand discharging pump located outside the tank body.

[0026] Optionally, the oil and slag removing device further includes a spraying mechanism, and the spraying mechanism includes an annular main pipeline and a plurality of spray nozzles;

[0027] The annular main pipeline is arranged at the top of the tank body;

[0028] A plurality of the spray nozzles are arranged at the bottom end of the annular main pipeline and can spray water columns in a conical shape towards the inner cavity of the tank body.

[0029] Furthermore, the present invention also provides a preparation method for preparing a carbon source from food waste, and the preparation method for preparing a carbon source from food waste is implemented based on the above-mentioned treatment equipment for preparing a carbon source from food waste. The preparation method includes:

[0030] Pump the slurry into the tank body;

[0031] Start the pickling tower, the gas in the tank body is sucked into the pickling tower for ammonia and nitrogen removal, and then flows back to the tank body through the second circulation coil to stir the slurry in the tank body;

[0032] Close the valve of the second circulation coil, open the valve of the first circulation coil, and adjust the air volume of the first circulation coil to make aeration and stirring alternate; the gas of the pickling tower is discharged into the tank body through the first circulation coil to perform ammonia stripping and air flotation oil removal on the slurry in the tank body;

[0033] Close the valve of the first circulation coil, open the valve of the slurry storage tank, and adjust the liquid level of the slurry in the tank body;

[0034] Start the oil and slag removing device, and the floating oil at the top end of the slurry and the sediment at the bottom end of the slurry are discharged into the oil and slag removing device;

[0035] Pump the slurry in the tank body out of the tank body for storage.

[0036] Optionally, the environment for the hydrolysis reaction in the tank body is micro-aerobic aeration and weak alkaline environment.

[0037] (III) Beneficial effects

[0038] The beneficial effects of the present invention are as follows: The double-circulation stirring device is connected to the pickling tower, and the pickling tower is connected to the tank body, enabling the gas in the tank body to be deammoniated and denitrified through the pickling tower and then refluxed to the tank body to form a reciprocating cycle, continuously reducing the proportion of ammonia and nitrogen in the slurry, thereby improving the quality of the carbon source.

[0039] Both the first circulation coil and the second circulation coil can stir the slurry in the tank body, improve the fluidity of the slurry, facilitate the full progress of the hydrolysis reaction, and effectively prevent sand accumulation at the inner wall dead angle at the bottom of the tank body and adhesion of floating oil on the inner wall of the tank body. Moreover, the first circulation coil is arranged above the second circulation coil, further improving the stirring effect of the second circulation coil.

[0040] Both the first circulation coil and the second circulation coil can aerate the slurry in the tank body for ammonia stripping and air flotation oil removal of the slurry. Ammonia stripping is to convert liquid elements such as ammonia and nitrogen in the slurry into gas phase, which is then adsorbed and removed by the pickling tower, thereby effectively reducing the ammonia and nitrogen content in the slurry. Air flotation oil removal is to create a large number of fine bubbles in the slurry. The fine bubbles can adhere to the suspended particles in the slurry. Due to the relatively small overall density, the fine bubbles can drive the suspended particles to float to the top surface of the slurry to form foam scum, which can ultimately be discharged into the oil and slag removal device together with the oil.

[0041] The slurry storage tank is connected to the tank body. The slurry storage tank can adjust the liquid level height of the slurry, thereby adjusting the liquid level height of the floating oil, effectively discharging the floating oil from the tank body, reducing the oil content in the slurry, and improving the quality of the carbon source.

[0042] The treatment equipment integrates functions of ammonia and nitrogen absorption, oil and slag removal, and hydrolysis, greatly reducing the number of equipment and optimizing the occupied space of the equipment. Moreover, the various mechanisms can cooperate with each other, and the operation efficiency is high. Description of the Drawings

[0043] Figure 1 It is a schematic structural diagram of the treatment equipment for preparing carbon source from kitchen waste of the present invention;

[0044] Figure 2 It is a schematic structural diagram of the tank body of the present invention;

[0045] Figure 3 It is a schematic structural diagram of an embodiment of the first circulation nozzle of the present invention;

[0046] Figure 4 It is a schematic structural diagram of another embodiment of the first circulation nozzle of the present invention.

[0047]

Explanation of the Reference Numerals

[0048] 1: Tank body; 11: Feed pipe; 12: Discharge pipe; 13: Thermometer; 14: pH meter; 15: Liquid level gauge; 16: Exhaust pipe; 17: Pressure gauge;

[0049] 2: First circulation coil; 21: Shell; 211: Flow guide groove; 22: Gravity check valve; 221: Exhaust hole;

[0050] 3: Second circulation coil;

[0051] 4: Pickling tower; 41: Fan;

[0052] 5: Slurry storage tank; 51: Heat exchanger;

[0053] 6: Oil discharge mechanism; 61: Overflow trough; 62: Scum box;

[0054] 7: Sand discharge mechanism; 71: Sand discharge pipe; 72: Sand discharge pump;

[0055] 8: Spraying mechanism; 81: Ring main pipe; 82: Clear water pipe;

[0056] 9: pH adjustment tank. Detailed implementation mode

[0057] In order to better explain the present invention for easy understanding, the present invention will be described in detail below with reference to the accompanying drawings through specific implementation modes.

[0058] It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the drawings). If the specific posture changes, the directional indications will also change accordingly.

[0059] In addition, the descriptions such as "first" and "second" in the present invention are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0060] In the present invention, unless otherwise clearly specified and defined, terms such as "connection" and "fixation" shall be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral one; "connection" can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication of two components or the interaction relationship between two components, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0061] See Figure 1 , the present invention provides a treatment device for preparing carbon source from kitchen waste. The treatment device includes a tank body 1, a double-cycle stirring device, an acid washing tower 4, an oil and slag removal device, and a slurry storage tank 5. The double-cycle stirring device includes a first circulation coil 2 and a second circulation coil 3 arranged in the tank body 1. The first circulation coil 2 is arranged above the second circulation coil 3; both the first circulation coil 2 and the second circulation coil 3 can aerate and stir the slurry in the tank body 1; the second circulation coil 3 is also communicated with the slurry storage tank 5; the air inlet of the acid washing tower 4 is communicated with the tank body 1, and the air outlet of the acid washing tower 4 is communicated with the first circulation coil 2 and the second circulation coil 3; the oil and slag removal device is communicated with the tank body 1, and the oil and slag removal device can pump out the floating oil at the top of the slurry and the sediment at the bottom of the slurry from the tank body 1. The floating oil includes grease and floating slag, etc., and has a certain viscosity. The sediment is large-particle precipitation such as sand and gravel; the slurry storage tank 5 is communicated with the tank body 1; the slurry storage tank 5 can adjust the liquid level height of the slurry. In the present invention, valves and hydraulic pumps are correspondingly arranged on the pipelines of the treatment device. The valves can be manual valves or solenoid valves, which are used to control the on-off of relevant pipelines; the hydraulic pumps play a pressurizing role and are used to enhance the fluidity of the slurry. The specific quantity and position of the valves and hydraulic pumps are set according to the technical solution of the present invention, and the present invention does not make a detailed description.

[0062] The double-cycle stirring device is communicated with the acid washing tower 4, and the acid washing tower 4 is communicated with the tank body 1, so that the gas in the tank body 1 can be deammoniated and denitrified by the acid washing tower 4 and then refluxed to the tank body 1 to form a reciprocating cycle, so as to continuously reduce the ammonia and nitrogen content in the slurry, thereby improving the quality of the carbon source.

[0063] Both the first circulation coil 2 and the second circulation coil 3 can stir the slurry in the tank body 1, improve the fluidity of the slurry, facilitate the full progress of the hydrolysis reaction, and effectively prevent sand accumulation at the inner wall dead angle at the bottom of the tank body 1 and the adhesion of floating oil on the inner wall of the tank body 1. And the second circulation coil 3 is arranged below the first circulation coil 2, that is, the second circulation coil 3 is closer to the bottom of the tank body 1, further improving the stirring effect of the second circulation coil 3.

[0064] Both the first circulation coil 2 and the second circulation coil 3 can aerate the slurry in the tank body 1, carry out ammonia stripping and air flotation for oil removal of the slurry. Ammonia stripping is to convert liquid elements such as ammonia and nitrogen in the slurry into gas phase, and then adsorbed and removed by the acid washing tower 4, so as to effectively reduce the ammonia and nitrogen content in the slurry. Air flotation for oil removal is to create a large number of fine bubbles in the slurry. The fine bubbles can adhere to the suspended particles in the slurry. Due to the relatively small overall density, the fine bubbles can drive the suspended particles to float to the top surface of the slurry, forming foam scum, and finally can be discharged into the oil and slag removal device together with the grease.

[0065] The slurry storage tank 5 is connected to the tank body 1. The slurry storage tank 5 can adjust the liquid level height of the slurry, so as to adjust the liquid level height of the floating oil, effectively discharge the floating oil from the tank body 1, reduce the grease content in the slurry, and improve the carbon source quality.

[0066] The processing equipment integrates functions of ammonia and nitrogen absorption, oil and slag removal, and hydrolysis, greatly reducing the number of equipment and optimizing the occupied space of the equipment. And each mechanism can carry out collaborative operations with high operation efficiency.

[0067] Furthermore, a plurality of first circulation nozzles are arranged on the first circulation coil 2, and the plurality of first circulation nozzles are arranged to incline upwards; a plurality of second circulation nozzles are arranged on the second circulation coil 3, and the nozzles on the second circulation coil 3 are arranged to incline downwards. Specifically, the downward arrangement of the second circulation nozzles enhances the scouring force on the inner wall of the bottom of the tank body 1, and the sediment at the bottom of the tank body 1 is not easy to adhere, which is convenient for subsequent discharge into the oil and slag removal device, and the second circulation nozzles can also carry out aeration synchronously. The traditional centrifugal pump is usually arranged at the bottom of the tank body 1 or communicated with the bottom of the tank body 1 to carry out stirring operations. However, sediment is easy to accumulate at the interface where the centrifugal pump is communicated with the tank body 1, which is not conducive to the subsequent treatment of the sediment; in this application, the second circulation coil 3 is used to replace the centrifugal pump, and the second circulation coil 3 is arranged above the bottom surface of the tank body 1 to blow and stir the sediment from top to bottom, effectively avoiding the interference of the stirring equipment on the subsequent sediment treatment operation and improving the slag discharge operation efficiency.

[0068] Similarly, the first circulation coil 2 is arranged upward, so that the floating oil on the top of the tank body 1 is not easily adhered, and while enhancing the fluidity of the floating oil, aeration is also carried out. On this basis, both the first circulation nozzle and the second circulation nozzle are arranged obliquely at a certain angle, so that the bubbles can move obliquely for a certain distance, and the bubbles are more likely to encounter particulate impurities and break, enhancing the dissolved oxygen efficiency of the slurry, and thus improving the hydrolysis reaction efficiency. On the other hand, the first circulation nozzle is arranged upward and above the second circulation nozzle, shortening the distance between the second circulation nozzle and the top surface of the slurry. Compared with the second circulation nozzle, the bubbles generated during aeration are not easily broken, and the bubbles can rise to the top surface of the slurry more quickly, so that the suspended particles in the slurry can be continuously concentrated to the top surface of the slurry. By the buoyancy of the continuously generated bubbles and the floating oil, the sinking of the suspended particles is prevented, effectively reducing the grease and scum content inside the slurry, which is beneficial to the progress of the hydrolysis reaction.

[0069] Secondly, the second circulation coil 3 is also connected to the slurry storage tank 5. Specifically, the slurry storage tank 5 stores slurry, but this part of the slurry has not been subjected to oil and slag removal treatment. By increasing the aperture of the second circulation nozzle, the slurry in the slurry storage tank 5 can be discharged into the tank body 1 through the second circulation nozzle, that is, the second circulation nozzle can both introduce gas and introduce materials (slag-containing slurry), thereby adjusting the liquid level of the slurry in the tank body 1. In an embodiment, a feed pipe 11 is arranged at the upper end of the tank body 1, so that the slurry can convert gravitational potential energy into kinetic energy, thereby enhancing the fluidity of the slurry and improving the hydrolysis reaction efficiency; at the same time, the pipeline of the slurry storage tank 5 is connected to the lower end of the tank body 1. When the slurry in the slurry storage tank 5 is discharged into the tank body 1, the floating oil accumulated at the top of the slurry in the tank body 1 will not be disrupted, and the bottom sediment can be scoured. In this embodiment, the feed pipe 11 and the pipeline of the slurry storage tank 5 are in parallel, and the slurry from the previous process is correspondingly discharged into the feed pipe 11 or the slurry storage tank 5.

[0070] Optionally, the slurry storage tank 5 is connected to the tank body 1 and the second circulation coil 3 to form a circulation pipeline, further enhancing the fluidity of the slurry; and a heat exchanger 51 is arranged in the circulation pipeline to adjust the temperature of the slurry in the tank body 1 to the value within the high-efficiency reaction temperature range of the hydrolysis reaction.

[0071] In this embodiment, a fan 41 is provided on the connecting pipe between the double-cycle stirring device and the pickling tower 4. Powered by the fan 41, the gas in the tank body 1 can circulate between the pickling tower 4 and the tank body 1. The fan 41 can adsorb the air in the atmosphere, thereby controlling the ratio of the air and nitrogen discharged into the tank body 1 for aeration, so as to form a micro-oxygen environment in the tank body 1. The micro-oxygen environment can promote the growth and reproduction of facultative anaerobes. The facultative anaerobes can effectively accelerate the hydrolysis process of macromolecular substances in the slurry by producing hydrolase and proteolytic enzyme, thereby increasing the SCOD concentration in the system. During the aeration process of the double-cycle stirring device, ammonia and nitrogen removal as well as oil and slag removal can be achieved synchronously, realizing the efficient cooperative operation of the double-cycle stirring device and the pickling tower 4.

[0072] As Figure 2 shown, in this embodiment, an exhaust pipe 16, a gas valve and a pressure gauge 17 are further provided at the top end of the tank body 1. The exhaust pipe 16 connects the inside and outside of the tank body 1. The gas valve controls the on-off of the exhaust pipe 16. The pressure gauge 17 displays the air pressure in the tank body 1 in real time, so as to adjust the air pressure in the tank body 1 and ensure the tank pressure during the slurry feeding and discharging process.

[0073] As Figure 3 shown, the diameter of the diversion groove 211 near the first circulation coil 2 is larger than that far from the first circulation coil 2. The direction indicated by the arrow in the figure is the flow direction of the medium in the first circulation nozzle. That is, the aperture of the air inlet of the diversion groove 211 is larger than that of the air outlet, so as to achieve the effect of outlet pressure increase and improve the gas pressure under the high-pressure stirring state. At the same time, the risk of large solid slag blocking the nozzle can be reduced.

[0074] See Figure 3 , the first circulation nozzle includes a housing 21 and a gravity check valve 22. The housing 21 is connected to the first circulation coil 2. The gravity check valve 22 is placed inside the housing 21. A diversion groove 211 is provided in the housing 21, and the diversion groove 211 is arranged between the gravity check valve 22 and the first circulation coil 2. A plurality of exhaust holes 221 are provided on the gravity check valve 22. Specifically, the gravity check valve 22 is improved on the basis of the existing gravity check valve, that is, a plurality of exhaust holes 221 are provided on the opening and closing member of the gravity check valve. When the air pressure in the housing 21 does not exceed the opening threshold of the gravity check valve 22, the first circulation nozzle performs aeration operation. When the air pressure in the housing 21 exceeds the opening threshold of the gravity check valve 22, the gravity check valve 22 opens, and the first circulation nozzle blows directly, that is, performs stirring operation. Optionally, the diversion groove 211 is an existing spiral groove or cross-shaped plate structure, and can also be set to other structures, as long as the gas or liquid flowing through the diversion groove 211 can flow out in a spiral shape. The medium flow direction is Figure 3In the direction indicated by the arrow, and a plurality of exhaust holes 221 formed in the check valve 22 can shear the gas to form fine bubbles. After the spiral gas or liquid collides with the check valve 22, the generation of bubbles can be intensified, further improving the stirring efficiency or aeration efficiency of the slurry.

[0075] It should be noted that the function of the gravity check valve 22 is not to prevent the backflow of the slurry. Preventing the backflow of the slurry can be achieved by a valve provided on the inlet pipe of the first circulation coil 2. The function of the gravity check valve 22 is to flexibly switch the aeration and stirring operations of the first circulation nozzle, realizing the integration of the two, simplifying the equipment, and reducing the equipment cost. In addition, the fluidity of the floating oil at the inner wall of the tank body 1 is poor because the bubbles rise in a straight line in the liquid and will break after colliding with the inner wall of the tank body 1. Therefore, there is no bubble breakage in the floating oil at the inner wall of the tank body 1, and the fluidity is poor. And the slurry often contains viscous substances and is easy to adhere to the inner wall of the tank body 1. The purpose of setting the first circulation nozzle in the present invention is to be able to stir the slurry regularly, maintain the fluidity of the floating oil, and effectively prevent the floating oil from adhering to the inner wall of the tank body 1.

[0076] In addition, the oil and slag removal device includes an oil drainage mechanism 6 and a sand drainage mechanism 7; the oil drainage mechanism 6 is communicated with the upper end of the slurry; the sand drainage mechanism 7 is communicated with the lower end of the slurry. The oil drainage mechanism 6 can collect the floating oil accumulated at the top of the slurry in the tank body 1, reduce the oil content in the slurry, and facilitate the hydrolysis reaction in the tank body 1. The sand drainage mechanism 7 can be periodically opened to drain sand, and control the liquid level height in the tank body 1 within a preset range. Optionally, a thermometer 13, a pH meter 14 and a liquid level meter 15 are arranged in the tank body 1 to control the temperature, acidity and alkalinity and the liquid level height of the slurry respectively, ensuring the efficient progress of the hydrolysis reaction and the smooth discharge of the floating oil.

[0077] Furthermore, the oil drainage mechanism 6 includes an overflow tank 61 and a scum box 62; the overflow tank 61 is formed on the inner wall of the tank body 1, and the overflow tank 61 is communicated with the scum box 62 located outside the tank body 1. The overflow tank 61 is arranged on the upper inner wall of the tank body 1, and the floating oil accumulated at the top of the slurry can drain into the overflow tank 61 due to its own gravity and finally be stored in the scum box 62. Therefore, there is no need to set a hydraulic pump on the pipeline of the oil drainage mechanism 6, simplifying the equipment.

[0078] In addition, the sand discharging mechanism 7 includes a sand discharging pipe 71 and a sand discharging pump 72; one end of the sand discharging pipe 71 is arranged at the bottom of the inner wall of the tank body 1, and the other end is communicated with the sand discharging pump 72 located outside the tank body 1. Large particles such as sand and gravel precipitate at the bottom of the slurry in the tank body 1, and the sand discharging pump 72 can be periodically started to discharge the large particle precipitate out of the tank body 1 and store it. In an embodiment, the first circulation nozzle and / or the second circulation nozzle are / is inclined at an angle of 60° with the horizontal plane, so that the double circulation stirring device can make the slurry flow in one direction during aeration and / or stirring, and the large particle precipitate is distributed at the inner wall of the tank body 1 under the action of centrifugal force, which can scour the dead corners at the inner wall of the tank body 1 and prevent the large particle precipitate at the dead corners from sticking. And after the double circulation stirring device is closed and left stationary for a period of time, the large particle precipitate can gather in the middle of the bottom of the tank body 1, which is convenient for the sand discharging pipe 71 to suck out.

[0079] Furthermore, the oil and slag removal device further includes a spraying mechanism 8; the spraying mechanism 8 is arranged at the top of the tank body 1 to be able to spray into the inner cavity of the tank body 1. The spraying mechanism 8 is located above the floating oil and can scour the floating oil, enhance the fluidity of the floating oil, and make the floating oil flow into the overflow tank 61, thereby improving the efficiency of the floating slag box 62 in collecting the floating oil.

[0080] Secondly, the spraying mechanism 8 includes an annular main pipe 81 and a plurality of spray nozzles; the annular main pipe 81 is arranged at the top of the tank body 1; the plurality of spray nozzles are arranged at the bottom end of the annular main pipe 81 and can spray conical water columns towards the inner cavity of the tank body 1. In this embodiment, the tank body 1 is provided with a conical top cover, and the water columns sprayed by the plurality of spray nozzles are also conical, which can cover the inner wall of the top cover and scour the top cover without dead corners, reducing the cost of manual cleaning.

[0081] In addition, the spraying mechanism 8 further includes a pH adjustment tank 9; the pH adjustment tank 9 is communicated with the spraying mechanism 8. Specifically, a clear water pipe 82 is externally connected to the spraying mechanism 8, and the clear water pipe 82 is connected in parallel with the pH adjustment tank 9. When it is necessary to adjust the pH value of the slurry, the pH adjustment tank 9 is opened to adjust the acidity and alkalinity of the slurry in the tank body 1 to ensure the efficient progress of the hydrolysis reaction. Through the collaborative operation of the plurality of spray nozzles and the pH adjustment tank 9, the inner wall of the tank body 1 can be cleaned, the floating oil can be drained, and the acidity and alkalinity of the slurry can be adjusted. The hydrolysis acidification process of the present invention is an alkaline system, which can promote the hydrolysis of oil in the slurry to generate organic substances such as carboxylic acids and alcohols, and at the same time can promote the forward progress of the hydrolysis acid production reaction. The micro-aerobic environment can inhibit the activity of methanogens and control the reaction process of converting small molecule organic acids such as VFAs in the system into methane, so as to obtain a carbon source rich in high-concentration VFAs and other small molecule organic substances while removing oil.

[0082] In addition, the present invention also provides a preparation method for preparing a carbon source from food waste. The preparation method for preparing a carbon source from food waste is implemented based on the above-mentioned treatment equipment for preparing a carbon source from food waste. The preparation method includes:

[0083] The kitchen waste is pretreated, including sorting, crushing, sand and impurity removal, to obtain a high-concentration organic slurry;

[0084] The slurry is pumped into the tank body 1 through the feed pipe 11;

[0085] The pickling tower 4 is started, and the gas in the tank body 1 is sucked into the pickling tower 4 for ammonia and nitrogen removal, and then flows back into the tank body 1 through the second circulation coil 3 to stir the slurry in the tank body 1, homogenize the slurry in the tank body 1, and improve the reaction efficiency;

[0086] After a preset time, the valve of the second circulation coil 3 is closed, the valve of the first circulation coil 2 is opened, and the air volume of the blower 41 is adjusted to make aeration and stirring alternate; the gas of the pickling tower 4 is discharged into the tank body 1 through the first circulation coil 2 to perform ammonia stripping and oil flotation on the slurry in the tank body 1;

[0087] The valve of the first circulation coil 2 is closed, the valve of the slurry storage tank 5 is opened, and the liquid level of the slurry in the tank body 1 is adjusted;

[0088] After standing for a set time, the oil and slag removal device is started, and the floating oil at the top of the slurry and the sediment at the bottom of the slurry are discharged into the oil and slag removal device; the sediment at the bottom of the slurry can also be regularly cleaned by starting the sand discharge pump 72;

[0089] The slurry in the tank body 1 is pumped out of the tank body 1 through the discharge pipe 12 for storage, and then subjected to solid-liquid separation through a solid-liquid separation system.

[0090] The present invention hydrolyzes the slurry through a processing device to hydrolyze the slurry into small molecule organic acids such as lactic acid and volatile fatty acids, that is, organic carbon sources. The organic carbon sources include solid carbon sources and liquid carbon sources. The solid carbon sources can be used for aerobic composting or insect breeding; the liquid carbon sources can be used as carbon sources in sewage treatment plants, such as providing carbon sources for anaerobic reactions in AO or AAO processes. The slurry treated by the processing device has a low ammonia nitrogen ratio, a high carbon source ratio, and a low oil ratio, and the hydrolysis reaction is sufficient, and finally the harmless and resource utilization of kitchen waste is realized.

[0091] Further, the hydrolysis reaction environment in the tank body 1 is a micro-aerobic aeration and weak alkaline environment. Specifically, the optimal parameters for directional acid production are: HRT 6 - 8d, pH 7.5 - 8, temperature 37.5 °C, and solid content 8 - 12%; the optimal parameters for gas stirring are: aeration intensity 1 - 2 vvm in the mixing stage, the stirring gas is nitrogen, and the stirring time is 0.5 - 1 h; the aeration intensity in the hydrolysis acidification stirring stage is 0.5 - 1 vvm, the stirring gas is a mixture of air / nitrogen at 0.2 - 0.4, the stirring time is 12 h, and intermittent aeration stirring is adopted; the process parameters for aeration stripping denitrification are: aeration intensity 0.4 - 0.6 vvm, aeration time 0.5 - 2 h, and the gas is a 1:1 mixture of nitrogen and air.

[0092] Among them, the micro-aerobic environment can promote the growth and reproduction of facultative anaerobic bacteria. The facultative anaerobic bacteria can effectively accelerate the hydrolysis process of macromolecular substances by producing hydrolysis enzymes and proteolytic enzymes. At the same time, the micro-aerobic environment can inhibit the activity of methanogens and control the reaction process of converting small molecule organic acids such as VFAs in the system into methane; while the weak alkaline system can promote the hydrolysis of oils and fats in the material to generate organic substances such as carboxylic acids and alcohols, and the forward progress of the hydrolysis acid production reaction, so as to obtain a carbon source rich in high-concentration small molecule organic substances such as VFAs while removing oils and fats.

[0093] The following is an example implemented based on the preparation method of the carbon source prepared from food waste of the present invention:

[0094] Step 1: The food waste is pretreated by sorting, crushing, pulping and impurity removal. After the kitchen waste is pretreated by bag breaking, sorting, crushing and extrusion and impurity removal, the liquid-phase slurries obtained from both are mixed. After simple oil extraction using an oil separation tank, a high-concentration organic slurry with properties of TS 6% - 8% and oil content 0.6% - 1% is obtained.

[0095] Step 2: The high-concentration organic slurry is transported to a hydrolysis acidification denitrification and oil removal device for reaction, and by controlling the hydrolysis conditions, high-concentration small molecule organic substances that are easily utilized by microorganisms are obtained; the process parameters for the hydrolysis acidification directional acid production are: HRT 6 - 8d, pH 7.5 - 8, temperature 37.5 °C, and solid content 6% - 8%; the process parameters for gas stirring are: aeration intensity 0.5 - 1 vvm, the stirring gas is a mixture of air / nitrogen at 0.2 - 0.4, the stirring time is 12 h, and intermittent aeration stirring is adopted; the process parameters for air flotation stripping denitrification are: aeration intensity 0.4 - 0.6 vvm, aeration time 30 min, and the gas is a 1:1 mixture of nitrogen and air.

[0096] Step 3: After the high-concentration carbon source slurry obtained from the hydrolysis acidification denitrification and oil removal device undergoes solid-liquid separation, the high-quality carbon source obtained can be supplied to the nearby sewage treatment plant. Among them, the SCOD concentration of the carbon source is > 40,000 mg / L, the VFAs content is > 25,000 mg / L, the ammonia nitrogen concentration is < 600 mg / L, and the oil and grease content is < 400 mg / L. The high-quality carbon source with a high carbon-nitrogen ratio and rich in small-molecule organic substances can be directly used as the carbon source for the sewage treatment plant.

[0097] It should be understood that the description of the specific embodiments of the present invention above is only for explaining the technical route and features of the present invention, and its purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly. However, the present invention is not limited to the above specific embodiments. Any changes or modifications made within the scope of the claims of the present invention should be covered by the protection scope of the present invention.

Claims

1. A treatment device for preparing carbon source from kitchen waste, characterized in that The processing device includes: a tank body (1); a double - circulation stirring device, which includes a first circulation coil pipe (2) and a second circulation coil pipe (3) arranged in the tank body (1), and the first circulation coil pipe (2) is arranged above the second circulation coil pipe (3); both the first circulation coil pipe (2) and the second circulation coil pipe (3) can aerate and stir the slurry in the tank body (1); a pickling tower (4), the air inlet of the pickling tower (4) is communicated with the tank body (1), and the air outlet of the pickling tower (4) is communicated with the first circulation coil pipe (2) and the second circulation coil pipe (3); an oil - and - slag removal device, which is communicated with the tank body (1), and the oil - and - slag removal device can pump out the floating oil at the top of the slurry and the sediment at the bottom of the slurry from the tank body (1); a slurry temporary storage tank (5), which is communicated with the tank body (1); the second circulation coil pipe (3) is also communicated with the slurry temporary storage tank (5); the slurry temporary storage tank (5) can adjust the liquid level height of the slurry; a plurality of first circulation nozzles are arranged on the first circulation coil pipe (2), and the plurality of first circulation nozzles are arranged to incline upwards; a plurality of second circulation nozzles are arranged on the second circulation coil pipe (3), and the nozzles on the second circulation coil pipe (3) are arranged to incline downwards; The first circulation nozzle includes a housing (21) and a gravity check valve (22); the housing (21) is communicated with the first circulation coil pipe (2); the gravity check valve (22) is built in the housing (21), and a plurality of exhaust holes (221) are opened on the gravity check valve (22); a diversion groove (211) is opened in the housing (21), and the diversion groove (211) is arranged between the gravity check valve (22) and the first circulation coil pipe (2); When the air pressure in the housing (21) does not exceed the valve - opening threshold of the gravity check valve (22), the first circulation nozzle performs aeration operation; when the air pressure in the housing (21) exceeds the valve - opening threshold of the gravity check valve (22), the gravity check valve (22) opens, and the first circulation nozzle directly blows air for stirring operation.

2. The treatment equipment for preparing carbon source from kitchen waste according to claim 1, characterized in that, The plurality of first circulation nozzles incline upwards at an angle of 60° with the coil pipe and the bottom of the tank; The nozzles on the second circulation coil pipe (3) incline downwards at an angle of 60° with the coil pipe and the bottom of the tank.

3. The processing equipment for preparing carbon source from kitchen waste according to claim 1, characterized in that, The caliber of the diversion groove (211) near the first circulation coil pipe (2) is larger than that far from the first circulation coil pipe (2).

4. The treatment equipment for preparing carbon source from kitchen waste according to any one of claims 1-3, characterized in that, The oil - and - slag removal device includes an oil - discharging mechanism (6) and a sand - discharging mechanism (7); The oil - discharging mechanism (6) is communicated with the upper end of the slurry; The sand - discharging mechanism (7) is communicated with the lower end of the slurry.

5. The treatment equipment for preparing carbon source from kitchen waste according to claim 4, characterized in that, The oil - discharging mechanism (6) includes an overflow groove (61) and a scum box (62); The overflow groove (61) is opened on the inner wall of the tank body (1), and the overflow groove (61) is communicated with the scum box (62) located outside the tank body (1).

6. The treatment equipment for preparing carbon source from kitchen waste according to claim 4, characterized in that, The sand discharging mechanism (7) includes a sand discharging pipe (71) and a sand discharging pump (72); One end of the sand discharging pipe (71) is arranged at the bottom of the inner wall of the tank body (1), and the other end is communicated with the sand discharging pump (72) located outside the tank body (1).

7. The treatment equipment for preparing carbon source from kitchen waste according to any one of claims 1-3, characterized in that, The oil and slag removing device further includes a spraying mechanism (8), and the spraying mechanism (8) includes an annular main pipe (81) and a plurality of spray nozzles; The annular main pipe (81) is arranged at the top of the tank body (1); A plurality of the spray nozzles are arranged at the bottom end of the annular main pipe (81) and can spray water columns in a conical shape towards the inner cavity of the tank body (1).

8. A preparation method of carbon source from kitchen waste, wherein the preparation method of carbon source from kitchen waste is implemented based on the treatment equipment for preparing carbon source from kitchen waste described in any one of claims 1-7, and is characterized in that, The preparation method includes: Pumping the slurry into the tank body (1); Starting the pickling tower (4), the gas in the tank body (1) is sucked into the pickling tower (4) for ammonia and nitrogen removal, and then flows back into the tank body (1) through the second circulation coil (3) to stir the slurry in the tank body (1); Closing the valve of the second circulation coil (3), opening the valve of the first circulation coil (2), and adjusting the air volume of the first circulation coil (2) to alternately perform aeration and stirring; the gas of the pickling tower (4) is discharged into the tank body (1) through the first circulation coil (2) to perform ammonia stripping and air flotation oil removal on the slurry in the tank body (1); Closing the valve of the first circulation coil (2), opening the valve of the slurry storage tank (5), and adjusting the liquid level of the slurry in the tank body (1); Starting the oil and slag removing device, and discharging the floating oil at the top end of the slurry and the sediment at the bottom end of the slurry into the oil and slag removing device; Pumping the slurry in the tank body (1) out of the tank body (1) for storage.

9. The preparation method of preparing carbon source from kitchen waste according to claim 8, characterized in that, The hydrolysis reaction environment in the tank body (1) is a micro-oxygen aeration and weak alkali environment.

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