CN105368710B - Anaerobic digestion device for kitchen waste - Google Patents

Abstract

The invention discloses an anaerobic digestion device for kitchen waste. A solid-phase reaction zone and a liquid-phase reaction zone are arranged in a reactor main body of the anaerobic digestion device, and an air outlet, a return water inlet, and a temperature measuring device are arranged on the top of the reactor. A sprinkler head is set at the lower part of the return water inlet, a water outlet is set under the liquid phase reaction zone, and a water inlet and a sludge discharge pipe are set at the bottom of the reactor. When anaerobic digestion of food waste is carried out, through the alternate operation of submerged anaerobic digestion and leaching reaction, the solid phase residue and liquid phase waste liquid of food waste can be fully anaerobic digestion reaction, with the maximum The degree enables the kitchen waste to be treated and realizes the maximum resource treatment.

Description

Anaerobic digestion device for food waste

This application is a divisional application of the invention patent application with the application number 201410178288.1 and the application date of April 29, 2014, and the invention name is "anaerobic digestion device and digestion method for kitchen waste".

technical field

The invention relates to an anaerobic digestion system, in particular to an anaerobic digestion device for kitchen waste.

Background technique

Food waste refers to food waste, catering leftovers, food processing waste and non-edible animal and vegetable oils and various oil-water mixtures from families, schools, institutions, public canteens and catering industries. It is part of urban domestic waste. At present, domestic kitchen waste treatment methods are mainly landfill and incineration together with domestic waste. The landfill treatment method will reduce the service life of the landfill. As for the incineration treatment method, only a few developed cities such as Shenzhen have adopted it. Waste incineration technology has been adopted, and the harmful gases, dust, waste water, etc. produced by incineration such as dioxin, nitrogen oxides, and sulfur dioxide have not been effectively controlled. In order to realize the sustainable development of resources, it is necessary to find a more effective treatment method to realize the effective recycling of kitchen waste, which is of great significance to the economic and environmental development of our country.

Anaerobic digestion is a series of processes in which microorganisms break down biodegradable materials in the absence of oxygen. Biodegradable materials include waste paper, kitchen waste, high-concentration organic wastewater, animal excrement and liquid waste, etc. Anaerobic digestion is suitable for the treatment of wet organic materials and is widely used in the treatment of organic waste.

For example, Chinese patent document CN 102939369 A (application number 201080063847.4) discloses an anaerobic reactor in the form of a tank, which is divided into separate chambers by solid components. Each chamber includes feed distribution systems, packed beds, and devices for biogas and liquid discharge. In use, the feed distribution system distributes feed substantially evenly across the base of each chamber. Each stacked reaction chamber preferably includes a mixing space containing or adapted to contain feed lines or a feed distribution system. The feed distribution system is operable to deliver and distribute feed to the base of the chamber and mix it with the anaerobic bacteria. Above the mixing space, a packed bed with an upper packing grid and a lower packing grid is usually arranged. Packed beds include packing media and anaerobic bacteria. The feed in the mixing space is primarily converted to volatile fatty acids, hydrogen and carbon dioxide by anaerobic bacteria included in the chamber. Any suitable packing media can be used in the packed bed. In order to provide a suitable environment for methanogenic bacteria, the packing medium has a high surface area to volume ratio. However, the structure of the anaerobic reactor is relatively complicated, and the inflow and outflow control of materials during operation is cumbersome.

Contents of the invention

The technical problem to be solved by the invention is to provide an anaerobic digestion device for kitchen waste with simple structure and high degree of digestion.

The technical solution for realizing the purpose of the present invention is an anaerobic digestion device for kitchen waste, comprising a reactor main body, an upper cover, a circulation pump, a water delivery pipeline, a return water pipeline, a control valve and a raw water pool; the circulation pump is a two-way circulation pump The upper cover is arranged on the top of the reactor main body to seal the cavity inside the reactor main body; the circulation pump transports the waste liquid in the raw water tank to the water inlet at the bottom of the reactor main body through the water delivery pipeline, and the circulation pump transports the waste liquid in the raw water tank to the water inlet at the bottom of the reactor main body through the water return pipeline The reaction liquid in the main body of the reactor is fed back into the reactor from above.

The interior of the reactor body is provided with a solid phase reaction zone and a liquid phase reaction zone, and the bottom of the reactor body is provided with a bottom sludge outlet; the liquid phase reaction zone includes upper and lower screens and packing between the two screens; The phase reaction zone is located above the upper screen, and the bottom of the solid phase reaction zone is provided with a sludge discharge port.

The upper cover is provided with a gas outlet, a return water inlet and a temperature measuring port; the gas outlet is connected to the gas outlet pipe, and the gas outlet pipe is connected to the gas storage tank; the return water inlet is connected to the water outlet of the return water pipeline; the temperature measuring port is set Temperature probe for detecting the temperature inside the reactor body.

The water delivery pipeline includes a first pipeline, a second pipeline, a third pipeline, a fourth pipeline and a water inlet pipe in sequence according to the flow direction of the liquid; the water inlet of the first pipeline is located below the liquid level in the raw water pool, and the water outlet of the first pipeline It is connected with the right port of the first tee, the left port of the first tee is connected with the water inlet of the second pipe, the water outlet of the second pipe is connected with the right port of the circulation pump, and the left port of the circulation pump is connected with the water inlet of the second pipe. The water inlet of the third pipe is connected, the water outlet of the third pipe is connected with the right port of the second tee, the upper port of the second tee is connected with the water inlet of the fourth pipe, and the water outlet of the fourth pipe is connected with the water inlet. The water inlet ends of the water pipes are connected, the water outlet ends of the water inlet pipes extend into the reactor body from the bottom of the reactor body, and the water outlet ends of the water inlet pipes are connected to the water distributor.

The return pipeline includes an outlet pipe, a fifth pipe, a sixth pipe, a seventh pipe, and an eighth pipe in sequence according to the flow direction of the liquid; The water inlet of the fifth pipe is connected, the water outlet of the fifth pipe is connected with the left port of the third tee, the right port of the third tee is connected with the sixth pipe, and the water outlet of the sixth pipe is connected with the liquid storage tank; The lower interface of the tee is connected to the water inlet of the seventh pipe, the water outlet of the seventh pipe is connected to the left interface of the second tee, and the seventh pipe passes through the second tee, the third pipe of the water delivery pipeline and the circulation pump The left port of the circulating pump is connected with the water inlet of the eighth pipe through the second pipe and the first tee of the water delivery pipeline, and the water outlet of the eighth pipe is connected with the water inlet end of the return water inlet pipe. The water outlet end of the return water inlet pipe extends into the reactor main body from the upper cover.

A method for anaerobic digestion of kitchen waste by an anaerobic digestion device for food waste as described above, comprising the following steps:

① Domestication of the strains, the domesticated strains are attached to the filler.

② Solid-liquid separation of kitchen waste, solid-liquid separation of kitchen waste, the solid content of the separated solid phase waste is 70% to 80%, and stored in the original mud pool; liquid phase waste, that is, waste liquid, is stored in the original In the pool to be treated.

③Material loading, open the upper cover on the top of the reactor main body, fill the space between the upper and lower screens in the liquid phase reaction zone with the filler of step ①, and anaerobic bacteria adhere to the inside of the filler; The solid phase waste is transferred to the top of the upper screen, and the height of the solid phase waste is 1/5 to 2/5 of the height of the main body of the reactor. After the solid phase waste is filled, the upper cover is closed.

④ Anaerobic digestion of food waste. The anaerobic digestion process of kitchen waste takes 24 to 42 days in total and consists of 3 to 5 digestion cycles. Each digestion cycle includes submerged anaerobic digestion process and leaching reaction in turn. process; in the submerged anaerobic digestion process, the waste liquid is submerged in the solid phase garbage; in the leaching reaction process, the reaction liquid in the liquid phase reaction zone is transported to the top of the reactor main body through the return pipe, and the reaction liquid is sprayed in the solid phase reaction area Above the solid waste; after 3 to 5 digestion cycles, the anaerobic digestion process of kitchen waste is completed.

The above steps 1. When domesticating the strains, take the raw mud in the anaerobic tank of the urban sewage treatment plant with a solid content rate of 5% to 7% and put it into the culture tank, put fillers in the culture tank, and put the raw mud in the culture tank When submerging the filler and acclimating the strains, add nutrient solution into the culture tank, and acclimatize the strains at 33°C to 37°C for 10 to 15 days.

In the above step 4, during the anaerobic digestion of food waste, when performing the submerged anaerobic digestion process of the first digestion cycle, open the control valve on the water delivery pipeline and close the control valve on the return water pipeline; turn on the circulation pump, and the circulation pump will convert the original The waste liquid in the pool is sent into the main body of the reactor from the water inlet pipe at the bottom of the main body of the reactor, and when the liquid surface is immersed in the top of the solid waste in the solid phase reaction area, the circulating pump is turned off, and the submerged anaerobic treatment starts. last for 4 to 7 days;

After the submerged anaerobic digestion process is over, close the control valve on the water delivery pipeline, open the control valve on the return water pipeline; turn on the circulation pump, and the circulation pump will transport the reaction liquid in the liquid phase reaction zone to the main body of the reactor through the return water pipeline The reaction solution is sprayed on top of the solid waste in the solid-phase reaction zone, and the solid waste in the solid-phase reaction zone undergoes a leaching reaction for 4 to 7 days to complete the first cycle of anaerobic digestion;

When carrying out the submerged anaerobic digestion process of the second digestion cycle, close the third control valve and the fifth control valve on the circulation pump and the return water pipeline; the sludge in the reactor main body is subjected to submerged anaerobic treatment for 4~ 7 days;

After the submerged anaerobic digestion process of the second digestion cycle is over, open the third control valve and the fifth control valve on the return water pipeline; turn on the circulation pump, and the circulation pump will pass the reaction liquid in the liquid phase reaction zone through the return water pipeline Transported to the top of the main body of the reactor, the reaction liquid is sprayed over the solid waste in the solid phase reaction area, and the solid waste in the solid phase reaction area undergoes a leaching reaction for 4 to 7 days, thus completing the second cycle of depletion of kitchen waste. Oxygen digestion process;

The steps from the third digestion cycle to the fifth digestion cycle are the same as the second digestion cycle.

The present invention has positive effects: (1) The digestion device of the present invention sends the liquid in the food waste to be treated into the reactor from the bottom water inlet of the reactor main body in the initial stage of anaerobic digestion by setting a bidirectional circulation pump Inside the main body, after anaerobic digestion for a period of time, the liquid inside the reactor main body is drawn out from the outlet pipe at the lower part of the reactor main body, and then transported to the top of the reactor, from the top of the reactor to the solid phase reaction inside the main body of the reactor Area spraying. A two-way circulation pump completes the liquid delivery of the reaction system, and the whole reaction device has a simple structure, convenient construction and easy operation.

(2) In the anaerobic digestion method of kitchen waste of the present invention, when the kitchen waste is anaerobically digested, the kitchen waste is firstly separated from the solid-liquid phase, and the solid-phase waste is stored in the raw mud pond, and the liquid-phase waste is The waste liquid is stored in the raw water pool; the solid waste to be treated is transferred to the solid reaction area of the reactor body of the digestion unit in advance, and the waste liquid in the raw water pool is transported by the circulating pump to the solid phase of the submerged solid reaction area inside the reactor body Garbage, after anaerobic digestion for a period of time, the reaction liquid in the reactor main body is pumped out from the lower part of the reactor main body and sprayed on the solid phase reaction area from the upper part. Through the alternate operation of submerged anaerobic digestion and leaching reaction, it can The solid-phase residue and liquid-phase waste liquid of the kitchen waste can be fully anaerobically digested, so that the kitchen waste can be treated to the greatest extent, and the resource treatment can be realized to the greatest extent. At the same time, in addition to processing kitchen waste, the device and method can also process organic solid waste such as chicken manure and urban sludge.

Description of drawings

Fig. 1 is the structural representation of anaerobic digestion device of the present invention;

The marks in the above drawings are as follows: reactor main body 1, solid phase reaction zone 11, sludge discharge port 11-1, liquid phase reaction zone 12, screen mesh 12-1, filler 12-2, bottom sludge discharge port 13;

Upper cover 2, air outlet pipe 21, return water inlet pipe 22, spray head 23, temperature measuring probe 24;

circulation pump 3;

Water pipeline 4, first pipeline 41, second pipeline 42, third pipeline 43, fourth pipeline 44; water inlet pipe 45, water distributor 45-1,

Return water pipeline 5, outlet pipe 51, fifth pipeline 52, sixth pipeline 53, seventh pipeline 54, eighth pipeline 55;

The first control valve 61, the second control valve 62, the third control valve 63, the fourth control valve 64, and the fifth control valve 65;

Raw water pool 7.

Detailed ways

(Example 1, anaerobic digestion device for kitchen waste)

Referring to FIG. 1 , the anaerobic digestion device for kitchen waste in this embodiment includes a reactor main body 1 , an upper cover 2 , a circulating pump 3 , a water delivery pipeline 4 , a return water pipeline 5 , a control valve and a raw water pool 7 . The upper cover 2 is arranged on the top of the reactor main body 1 to seal the cavity inside the reactor main body 1 . The circulation pump 3 transports the waste liquid in the raw water tank 7 to the water inlet of the reactor main body 1 through the water delivery pipeline 4, and the circulation pump 3 sends the reaction liquid inside the reactor main body 1 back from the top of the reactor through the return water pipeline 5. Inside Reactor 1.

The interior of the reactor main body 1 is provided with a solid phase reaction zone 11 and a liquid phase reaction zone 12 , and a bottom sludge outlet 13 is provided at the bottom of the reactor main body 1 . The liquid phase reaction zone 12 is arranged at the lower part of the inner cavity of the reactor main body 1 , and the solid phase reaction zone 11 is located above the liquid phase reaction zone 12 .

The liquid phase reaction zone 12 includes upper and lower screens 12-1 and packing 12-2 between the two screens. The distance between the lower screen 12 - 1 and the bottom of the reactor body 1 is 1/10-1/5 of the height of the reactor body 1 . The distance between the upper screen and the lower screen is 2/5-3/5 of the height of the reactor main body 1 . Both the upper screen and the lower screen are made of 304 stainless steel, and the mesh numbers of the upper screen and the lower screen are both 500 mesh.

Filler 12-2 fills up the space between upper and lower screen cloth 12-1. Biofilm is attached to the filler 12-2, and the filler contains anaerobic bacteria. In order to provide a suitable growth environment for the anaerobic bacteria, the material selected for the filler 12-2 has a high surface area/volume ratio. The filler 12-2 used in this example was purchased from Yixing Gaocheng Hengguang Environmental Protection Equipment Factory. The silk is pressed onto a semi-soft polymer inner ring. The biofilm is a microbial film attached to the filler after being cultivated and acclimated. When the filler starts to form a film, it starts to form a film from the soft filler at the edge of the vinylon, and after a week, the biofilm will extend to the inner circle. On the soft filler, both softness and semi-softness can produce effects, and finally achieve a better treatment effect.

The upper screen 12-1 is fixed inside the reactor main body 1 through 4 or more hooks arranged at equal intervals on the inner wall of the reactor main body 1, and the fixing method of the lower screen 12-1 is the same as that of the upper screen 12-1. 1 is the same.

The solid phase reaction zone 11 is located above the upper screen 12-1. The height of the solid phase reaction zone 11 is 1/5-2/5 of the height of the reactor main body 1 . A sludge discharge port 11-1 is provided at the bottom of the solid phase reaction zone 11, and the sludge discharge port 11-1 is located above the upper screen 12-1.

The upper cover 2 is provided with an air outlet, a return water inlet and a temperature measuring port. The gas outlet is connected with the gas outlet pipe 21, and the gas outlet pipe 21 is connected with the gas storage tank. The backflow water inlet is connected with the backflow water inlet pipe 22 , and the water outlet of the backflow water inlet pipe 22 is provided with a spray head 23 . A temperature measuring probe 24 is arranged in the temperature measuring port for detecting the temperature inside the reactor main body 1 .

The circulation pump 3 is a bidirectional circulation pump, and the bidirectional circulation pump used in this embodiment is a model JL350-2J bidirectional circulation pump of Baoding Lange Constant Flow Pump Co., Ltd.

The water delivery pipeline 4 sequentially includes a first pipeline 41 , a second pipeline 42 , a third pipeline 43 , a fourth pipeline 44 and a water inlet pipe 45 according to the flow direction of the liquid. The water inlet of the first pipeline 41 is located below the liquid level in the raw water pool 7, the water outlet of the first pipeline 41 is connected with the right interface of the first tee, and the left interface of the first tee is connected with the water inlet of the second pipeline 42 The outlet end of the second pipeline 42 is connected with the right port of the circulation pump 3, the left port of the circulation pump 3 is connected with the water inlet end of the third pipeline 43, and the water outlet end of the third pipeline 43 is connected with the second three-way port. The right interface is connected, the upper interface of the second tee is connected with the water inlet end of the fourth pipeline 44, the water outlet end of the fourth pipeline 44 is connected with the water inlet end of the water inlet pipe 45, and the water outlet end of the water inlet pipe 45 is connected from the reactor main body The bottom of 1 extends into the reactor main body 1, and the water outlet end of the water inlet pipe 45 is connected to the water distributor 45-1.

The return water pipeline 5 includes an outlet pipe 51 , a fifth pipeline 52 , a sixth pipeline 53 , a seventh pipeline 54 and an eighth pipeline 55 in sequence according to the flow direction of the liquid. The water inlet port of the water outlet pipe 51 is located at the lower end of the liquid phase reaction zone 12, and the water outlet of the water outlet pipe 51 is connected with the water inlet of the fifth pipe 52, and the water outlet of the fifth pipe 52 is connected with the left interface of the third tee. The right interface of three three links links to each other with the sixth pipeline 53, and the water outlet of the sixth pipeline 53 connects liquid storage tank; The lower interface of the third three links links to each other with the water inlet of the seventh pipeline 54, and the water outlet of the seventh pipeline 54 is connected with The left interface of the second tee is connected, the seventh pipeline 54 is connected with the left port of the circulation pump 3 through the second tee, the third pipeline 43 of the water delivery pipeline 4, and the right side port of the circulation pump 3 is passed through the water delivery pipeline The second pipe 42 of 4 and the first tee are connected with the water inlet of the eighth pipe 55, and the water outlet of the eighth pipe 55 is connected with the water inlet end of the return water inlet pipe 22, and the water outlet end of the backflow water inlet pipe 22 is connected from the upper cover 2 into the reactor main body 1.

The return water pipeline 5 and the water delivery pipeline 4 share a section of pipeline, which can simplify pipeline design and save infrastructure investment.

The control valves include a first control valve 61 , a second control valve 62 , a third control valve 63 , a fourth control valve 64 and a fifth control valve 65 , which are respectively arranged on corresponding pipelines. Wherein the first control valve 61 is arranged on the first pipe 41 of the water delivery pipeline 4, the second control valve 62 is arranged on the water inlet pipe 45 of the water delivery pipeline 4, and the third control valve 63 is arranged on the water outlet pipe of the return water pipeline 5 51 , the fourth control valve 64 is set on the sixth pipe 53 of the return water line 5 , and the fifth control valve 65 is set on the eighth line 55 of the return water line 5 .

The digestion device of the present invention is provided with a two-way circulation pump, and in the initial stage of anaerobic digestion, the liquid in the food waste to be treated can be sent from the bottom water inlet of the reactor body into the interior of the reactor body, and wait for anaerobic digestion for a period of time Finally, the liquid inside the reactor body is drawn out from the outlet pipe at the lower part of the reactor body, and then transported to the top of the reactor, and sprayed from the top of the reactor to the solid phase reaction area inside the reactor body. A two-way circulating pump completes the liquid delivery of the reaction system. The entire reaction device has a simple pipeline design, a simple structure, and is convenient for construction and operation.

The digestion device of the present invention separates the solid-phase reaction zone 11 and the liquid-phase reaction zone 12 in the interior of the reactor main body 1, instead of directly anaerobic digestion inside the reactor main body 1 after mixing the food waste and bacteria, so that the liquid Phase waste has higher digestion efficiency, and solid phase waste can also be fully digested to improve the overall gas production rate of waste digestion. At the same time, it has the advantages of easy separation of solid phase and liquid phase and thorough reaction.

(Example 2, the anaerobic digestion method of kitchen waste)

The device used in the anaerobic digestion method of kitchen waste in this example is the anaerobic digestion device described in Example 1.

The anaerobic digestion method of the kitchen waste of the present embodiment comprises the following steps:

① Domestication of strains. Take the raw mud in the anaerobic tank of the urban sewage treatment plant with a solid content of 5% to 7% and put it into the cultivation tank, put the filler 12-2 in the cultivation tank, and submerge the raw mud in the cultivation tank with the filler 12-2 , when acclimating the strains, in order to meet the needs of microbial growth in the culture tank, add nutrients glucose, N, P and trace elements Fe, Co, Ni to the culture tank, add 10L of culture solution; the strains were acclimatized for 10-15 days at medium temperature (35±2°C). After the acclimatization is completed, the anaerobic strain obtained after acclimatization is attached to the filler 12-2.

In the culture solution, every 1L culture solution contains 1.03g glucose, 1g sodium bicarbonate nitrogen, 0.26g ammonium chloride, 45mg magnesium sulfate, 30mg dipotassium hydrogen phosphate, 25mg sodium citrate, 15mg calcium chloride, 1mg nickel sulfate , 4mg ferric chloride, etc.

② Solid-liquid separation of kitchen waste. Send food waste, catering leftovers, food processing waste, non-edible animal and vegetable oils and various oil-water mixtures from families, schools, institutions, public canteens and catering industries into the three-phase screw extrusion dehydrator for solid-liquid separation , the solid-phase garbage obtained by separation has a solid content rate of 70% to 80%, and is stored in the raw mud pool; liquid-phase garbage, that is, waste liquid, is stored in the raw water pool 7 to be treated.

Step ① and step ② are in no particular order in time.

③ Loading of materials. Open the upper cover 2 on the top of the reactor main body 1, and fill the upper and lower screens of the liquid phase reaction zone 12 with the filler 12-2 taken out from the culture tank in step ①, and the anaerobic bacteria adhere to the filler 12-2. 2 inside; then transfer the solid-phase garbage in the raw mud tank to the top of the upper screen, and the height of the solid-phase garbage is 1/5 to 2/5 of the height of the reactor main body 1. Cover the upper cover 2 after the solid-phase garbage has been loaded.

④ Anaerobic digestion of food waste. The anaerobic digestion process of food waste takes 24 to 42 days in total and consists of 3 to 5 digestion cycles, and each cycle includes an immersion anaerobic digestion process and a leaching reaction process in sequence. That is, in the anaerobic digestion process, the submerged anaerobic digestion process and the leaching reaction process are carried out alternately.

When carrying out the submerged anaerobic digestion process of the first digestion cycle, open the first control valve 61 and the second control valve 62 on the water delivery pipeline 4, close the third control valve 63 and the fourth control valve on the return water pipeline 5 Valve 64 and fifth control valve 65; turn on the circulating pump 3, and the circulating pump 3 sends the waste liquid in the raw water pool 7 from the water inlet pipe 45 at the bottom of the reactor main body 1 into the reactor main body 1, and wait for the liquid surface to be immersed in the solid phase reaction On the top of the solid waste in zone 11, the submerged anaerobic digestion process of kitchen waste starts, and the submerged anaerobic treatment lasts for 4-7 days (5 days in this embodiment). In the submerged anaerobic digestion process, the oxidation reduction potential ORP is -200~-350mv, and the anaerobic digestion temperature is 35~40°C. After the submerged anaerobic digestion process ends, close the first control valve 61 and the second control valve 62 on the water delivery pipeline 4, open the third control valve 63 and the fifth control valve 65 on the return water pipeline 5; open the cycle The pump 3 and the circulating pump 3 transport the reaction liquid in the liquid phase reaction zone 12 to the top of the reactor main body 1 through the return pipe 5, and the reaction liquid is sprayed on the solid waste in the solid phase reaction zone 11, and the solid phase reaction zone 11 The solid waste is subjected to leaching reaction for 4-7 days (5 days in this embodiment), so as to complete the anaerobic digestion process of the first cycle of the kitchen waste. During the leaching process, the oxidation-reduction potential ORP is -200~-350mv, and the temperature of solid waste is 35~40°C.

When carrying out the submerged anaerobic digestion process of the second digestion cycle, close the third control valve 63 and the fifth control valve 65 on the circulation pump 3 and the return water pipeline 5; The oxygen treatment was continued for 4-7 days (5 days in this example).

After the submerged anaerobic digestion process of the second digestion cycle ends, open the third control valve 63 and the fifth control valve 65 on the return water pipeline 5; The reaction liquid is transported to the top of the reactor main body 1 through the return water pipeline 5, and the reaction liquid is sprayed on the solid waste in the solid phase reaction area 11, and the solid waste in the solid phase reaction area 11 undergoes a leaching reaction for 4 to 7 days (this In the embodiment, it is 5 days), so as to complete the anaerobic digestion process of the second cycle of the kitchen waste.

The steps from the third digestion cycle to the fifth digestion cycle are the same as the second digestion cycle. Three digestion cycles were included in this example.

After the anaerobic digestion of the kitchen waste is completed, the circulating pump 3 is turned off, and the mud outlet 11-1 below the solid phase reaction zone 11 is opened to discharge the digested solid waste, which can be used for landscape after killing pathogenic bacteria , forest land and agricultural fertilizers. Open the third control valve 63 and the fourth control valve 64 on the return line 5 to discharge the reaction liquid out of the main body of the reactor. The concentration of organic matter in the digested reaction liquid is greatly reduced, and after entering the sewage treatment facility in the factory area for further treatment, it can be discharged into sewage Pipeline, into the sewage treatment plant for unified treatment.

The methane produced in the anaerobic digestion process is discharged from the outlet pipe 21 and collected in the gas storage tank.

In this example, through submerged anaerobic digestion and leaching reaction, under the anaerobic condition of the kitchen waste, the kitchen waste sludge can be converted into clean energy through anaerobic fermentation—methane through the action of microorganisms, which can not only solve the problem of kitchen waste Disposal of garbage can also reduce dependence on fossil fuels to a certain extent, thereby reducing environmental pollution caused by the use of fossil fuels. It can bring significant economic and environmental ecological benefits to the society, and has an extremely attractive application prospect in the 21st century when green chemistry and clean chemistry are advocated.

(Application example 1)

Take the kitchen waste from the school canteen, before the anaerobic digestion treatment, the COD value of the liquid phase waste liquid is 120000mg/L; after the anaerobic digestion treatment according to the method of Example 2, the COD value of the waste liquid drops to 6000~ 8000mg/L, the digested solid waste loses more than 88% of its weight. Collect 562.21L of methane.

As a comparison, 1 kg of kitchen waste from the school canteen was also taken. Before anaerobic digestion treatment, the COD value of the liquid phase waste liquid was 120,000 mg/L. When carrying out anaerobic digestion, the kitchen waste is directly mixed with 0.3 kg of domesticated sludge, and the sludge domestication method is the same as step ① in Example 2. After 30 days of anaerobic digestion, the COD value of the waste liquid dropped to 10000-13000mg/L. Collect 489.12L of methane.

Therefore, the digestion device and method of the present invention make the liquid-phase waste obtained by the solid-liquid separation of kitchen waste have higher digestion efficiency, and at the same time, the solid-phase waste can also be fully digested, and the overall gas production of the waste is improved.

Claims (1)

1. A kind of 1. anaerobic digestion device of kitchen garbage, it is characterised in that：Including reactor body（1）, upper cover（2）, circulating pump （3）, hydraulic pipeline（4）, water return pipeline（5）, control valve and former pond（7）；Circulating pump（3）For bidirectional circulating pump；

   Upper cover（2）It is arranged on reactor body（1）Top, seal reactor body（1）Internal cavity；Upper cover（2）On set There are gas outlet, reflux water inlet and temperature-measuring port；Gas outlet and air outlet pipe（21）It is connected, air outlet pipe（21）With gas reservoir phase Even；Flow back water inlet and water return pipeline（5）Water outlet be connected；Set in temperature-measuring port and be used to detect reactor body（1）It is interior The temperature probe of the temperature in portion（24）；

   Circulating pump（3）Pass through hydraulic pipeline（4）By former pond（7）In waste liquid be delivered to reactor body（1）The water inlet of bottom Mouthful, circulating pump（3）Pass through water return pipeline（5）By reactor body（1）Internal reaction solution flows back from top and is sent into reactor（1） It is internal；

   Reactor body（1）Be internally provided with solid phase reaction area（11）With liquid phase reactor area（12）, reactor body（1）Bottom Equipped with bottom mud discharging mouth（13）；Liquid phase reactor area（12）Including upper and lower sieve（12-1）Filler between two sieves（12- 2）；Solid phase reaction area（11）The top for the upper screen cloth being located at, solid phase reaction area（11）Bottom be equipped with mud discharging mouth（11-1）；

   The hydraulic pipeline（4）Include the first pipeline successively according to the flow direction of liquid（41）, second pipe（42）, the 3rd pipeline （43）, the 4th pipeline（44）And water inlet pipe（45）；First pipeline（41）Water inlet be located at former pond（7）Below interior liquid level, First pipeline（41）Water outlet be connected with the right interface of the first threeway, the left interface and second pipe of the first threeway（42）Into Water end (W.E.) is connected, second pipe（42）Water outlet and circulating pump（3）Right side port be connected, circulating pump（3）Left side port with 3rd pipeline（43）Water inlet end be connected, the 3rd pipeline（43）Water outlet and the right interface of the second threeway be connected, the two or three Logical upper interface and the 4th pipeline（44）Water inlet end be connected, the 4th pipeline（44）Water outlet and water inlet pipe（45）Water inlet end It is connected, water inlet pipe（45）Water outlet from reactor body（1）Bottom stretch into reactor body（1）It is interior, water inlet pipe（45）'s Water outlet connects water distributor（45-1）；

   The water return pipeline（5）Include outlet pipe successively according to the flow direction of liquid（51）, the 5th pipeline（52）, the 6th pipeline （53）, the 7th pipeline（54）With the 8th pipeline（55）；Outlet pipe（51）Water inlet port be located at liquid phase reactor area（12）Lower end, Outlet pipe（51）Water outlet and the 5th pipeline（52）Water inlet be connected, the 5th pipeline（52）Water outlet and the 3rd threeway Left interface is connected, the right interface and the 6th pipeline of the 3rd threeway（53）It is connected, the 6th pipeline（53）Water outlet connect fluid reservoir；The The lower interface of three threeways and the 7th pipeline（54）Water inlet be connected, the 7th pipeline（54）Water outlet and a left side for the second threeway connect Mouth is connected, the 7th pipeline（54）Pass through the second threeway, hydraulic pipeline（4）The 3rd pipeline（43）With circulating pump（3）Left side Port is connected, circulating pump（3）Right side port pass through hydraulic pipeline（4）Second pipe（42）With the first threeway and the 8th pipeline （55）Water inlet be connected, the 8th pipeline（55）Water outlet with reflux water inlet pipe（22）Water inlet end be connected, flow back water inlet pipe （22）Water outlet from upper cover（2）Stretch into reactor body（1）It is interior.