Anaerobic digestion sludge pretreatment device for digestion tank of urban sewage plant

Abstract

According to the anaerobic digestion sludge pretreatment device for the digestion tank of the urban sewage plant, slurry is introduced into a slurry distribution tank, one path of an outlet of the slurry distribution tank is communicated with a static concentration tank, the other path of the outlet of the slurry distribution tank is communicated with a condensation device, the static concentration tank is communicated with a flora culture tank, and the flora culture tank is communicated with a mixing tank; the alkali liquor preparation device supplies hot water to the flora culture pond, cold water subjected to circulating cooling returns to the alkali liquor preparation device, the mixing tank is communicated with the second grinding machine, the second grinding machine is communicated with the slurry hot water exchanger, the condensation device is communicated with the first grinding machine, the first grinding machine is communicated with the centrifugal machine, and the centrifugal machine is communicated with the aerobic device. The aerobic device is communicated with the alkali liquor adjusting device, alkali liquor is supplied to the alkali liquor adjusting device through the alkali liquor preparing device, the problems that in the prior art, sludge is low in organic matter content, uneven in pH value, large in temperature fluctuation, capable of blocking pipelines and the like can be effectively solved, and the device can be popularized to the field of sludge pretreatment of digestion tanks of urban sewage plants.

Description

Technical Field

[0001] The utility model belongs to the technical field of sludge treatment devices or equipment, and specifically relates to an anaerobic digestion sludge pretreatment device for a digester in a municipal sewage plant. Background Art

[0002] At present, the treatment technology of residual sludge from urban sewage treatment plants has become the key development direction of urban environmental pollution prevention and control and green low-carbon resource recycling. Anaerobic digestion of sludge refers to the process in which facultative bacteria and anaerobic bacteria decompose the biodegradable organic matter in the sludge into carbon dioxide, methane and water under anaerobic conditions to stabilize the sludge. It is one of the effective means of sludge reduction, stabilization, harmlessness and resource treatment. Through investigation, it was found that the main factors affecting the gas production rate of anaerobic digestion of digester sludge are low organic matter content in digested sludge, uneven sludge pH, large sludge temperature fluctuations, mud blocking pipelines and other problems. At present, the sludge before digestion is mostly treated by one-time dehydration and alkali treatment. This process does not recycle the heat generated by the alkali treatment, resulting in energy waste. Although the sludge contains microorganisms, the number is small. Although simple alkali treatment can destroy the cell wall of microorganisms and dissolve organic matter, the increase in the organic matter content in the sludge is still not ideal due to the small number of microorganisms. In addition, anaerobic microorganisms are not pre-cultured, so the sludge digestion takes a long time and has a low yield. In order to solve the above technical problems, the utility model provides an anaerobic digestion sludge pretreatment device for a digester of a municipal sewage plant. Summary of the invention

[0003] The technical problem to be solved by the utility model is to overcome the deficiencies of the above-mentioned prior art and provide an anaerobic digestion sludge pretreatment device for a digester of a municipal sewage plant, which has a simple structure, saves resources, reduces the sludge digestion and gas production time of the digester, and has a high unit sludge gas production rate.

[0004] The technical solution adopted to solve the above technical problems is: an anaerobic digestion sludge pretreatment device for a digester of a municipal sewage plant, wherein the sludge is introduced into a sludge distribution tank, the outlet of the sludge distribution tank is connected to the inlet of a static concentration tank through a pump installed on a pipeline, and is connected to the inlet of a condensation device in another way, the outlet of the static concentration tank is connected to the inlet of a bacterial culture tank, the outlet of the bacterial culture tank is connected to the inlet of a mixing tank, an alkali solution preparation device supplies hot water to the bacterial culture tank, and the cold water after circulating cooling returns to the alkali solution preparation device, the mixing tank is connected to the inlet of a second grinder through a pump installed on a pipeline, the outlet of the second grinder is connected to the inlet of a sludge hot water exchanger, the outlet of the condensation device is connected to the inlet of a first grinder, the outlet of the first grinder is connected to the inlet of a centrifuge, the outlet of the centrifuge is connected to the inlet of an aerobic device, the outlet of the aerobic device is connected to the inlet of an alkali solution regulating device, and the alkali solution regulating device is supplied with alkali solution by the alkali solution preparation device.

[0005] The utility model discloses an alkali solution preparation device as follows: an alkali preparation agitator is arranged inside a lime reaction tank, a second water tank is connected with an inlet of the lime reaction tank through a second clean water pump installed on a pipeline, an outlet of the lime reaction tank is connected with an alkali solution regulating device through an alkali solution pump installed on a pipeline, a cold water heating tank is concentrically arranged outside the lime reaction tank, a second temperature detector is arranged at the bottom of the cold water heating tank, water in the cold water tank enters an upper part of an interlayer formed by the cold water heating tank and the lime reaction tank through the cold water pump, a lower part of the interlayer formed by the cold water heating tank and the lime reaction tank is connected with an inlet of a hot water tank through a first water outlet valve installed on a pipeline, an outlet of the hot water tank is connected with an inlet of a bacterial colony culture device through a hot water pump installed on a pipeline, and an inlet of the cold water tank is connected with an outlet of the bacterial colony culture device.

[0006] The bacterial colony culture device of the utility model is as follows: the culture tank is a sealed structure, a heating coil is arranged at the bottom of the culture tank, the inlet of the heating coil is connected with the hot water pump, and the outlet is connected with the cold water tank through a first temperature detector and a first water outlet valve installed on the pipeline, a mud circulation pump is arranged outside the culture tank, a culture tank agitator is arranged on the upper part of the culture tank, and the outlet of the culture tank is connected with the inlet of the mixing tank through the first mud pump installed on the pipeline.

[0007] The aerobic device of the utility model comprises: an air duct is arranged on the top of the aerobic pool, the air duct is connected with the ventilator, branch pipes extending into the aerobic pool are vertically arranged at intervals of 50cm on the air duct, and air outlet holes are evenly distributed on the branch pipes.

[0008] The lower part of the aerobic pool of the utility model is a V-shaped chamber, the upper part is a rectangular chamber, and the top of the aerobic pool is open.

[0009] The coagulation device of the utility model is as follows: the flocculant is sent into the flocculant preparation tank through a screw conveyor, a plurality of flocculant agitators are arranged in the flocculant preparation tank, a first water tank is connected with the flocculant preparation tank through a first clean water pump installed on a pipeline, an outlet of the flocculant preparation tank is connected with a coagulation tank through a flocculant supply pump installed on a pipeline, mud is introduced into the coagulation tank for precipitation and agglomeration, and the outlet of the coagulation tank is connected with the inlet of a first grinder through a second mud pump installed on a pipeline.

[0010] The lower part of the static concentration tank of the utility model is provided with a mud scraper.

[0011] Compared with the prior art, the utility model has the following advantages:

[0012] (1) The utility model divides the slurry produced by the sewage treatment plant into two parts. One part is used to cultivate anaerobic bacteria in the sludge through a bacteria colony cultivation device. The cultivation of anaerobic bacteria can reduce the gas production time of sludge digestion in the digestion tank. The other part is dehydrated twice, and the slurry dehydrated by the centrifuge undergoes aerobic reaction to enable the rapid growth of aerobic microorganisms, so that more organic matter can be dissolved by the subsequent lye treatment.

[0013] (2) When preparing lye, the utility model uses the heat released during the preparation of lye by adding water to lime to provide heat for cultivating the bacteria colony. No additional heat is required for cultivating the bacteria colony. The prepared lye is introduced into the lye adjustment device for alkali treatment of the slurry. This process realizes the recycling of heat and water and saves resources.

[0014] (3) The mixing tank of the utility model can evenly stir the cooked slurry, the slurry after anaerobic cultivation, and the slurry after alkali treatment, and grind the sludge into fine particles without clogging the tubular heat exchanger and pipelines. Description of the Drawings

[0015] Figure 1 is a schematic structural diagram of an embodiment of the utility model.

[0016] Figure 2 is Figure 1 the schematic structural diagram of the bacteria colony cultivation device 3 in

[0017] Figure 3 is Figure 1 the schematic structural diagram of the condensation device 4 in

[0018] Figure 4 is Figure 1 the schematic structural diagram of the lye preparation device 9 in

[0019] In the figure: 1, mud distribution tank; 2, static thickening tank; 3, flora cultivation device; 4, coagulation device; 5, first grinder; 6, centrifuge; 7, aerobic device; 8, lye regulating device; 9, lye preparation device; 10, mixing tank; 11, second grinder; 12, mud hot water exchanger; 3-1, main body of cultivation tank; 3-2, first mud pump; 3-3, first temperature detector; 3-4, first water outlet valve; 3-5, mud circulation pump; 3-6, stirrer of cultivation tank; 3-7, heating coil; 4-1, screw conveyor; 4-2, flocculant preparation tank; 4-3, flocculant stirrer; 4-4, first clean water pump; 4-5, first water tank; 4-6, flocculant supply pump; 4-7, main body of coagulation tank; 4-8, second mud pump; 7-1, ventilator; 7-2, air duct; 7-3, branch pipe; 7-4, aerobic tank; 9-1, cold water heating tank; 9-2, lime reaction tank; 9-3, stirrer for lye preparation; 9-4, second clean water pump; 9-5, second water tank; 9-6, lye pump; 9-7, second temperature detector; 9-8, second water outlet valve; 9-9, hot water tank; 9-10, hot water pump; 9-11, cold water tank; 9-12, cold water pump. Detailed implementation manners

[0020] The following further describes the present utility model in detail with reference to the accompanying drawings and embodiments, but the present utility model is not limited to these embodiments.

[0021] Embodiment 1

[0022] In Figures 1 to 4 this, a pretreatment device for anaerobic digestion sludge in a digestion tank of an urban sewage treatment plant according to the present utility model, the mud is introduced into the mud distribution tank 1. The outlet of the mud distribution tank 1 is connected to the inlet of the static thickening tank 2 through a pump installed on the pipeline and to the inlet of the coagulation device 4 through another path. In this embodiment, the mud in the mud distribution tank 1 is divided into mud one and mud two in a ratio of 1:5. The mud one is pumped into the static thickening tank 2, and the mud two is pumped into the coagulation device 4. The mud one is thickened by its own weight in the static thickening tank 2 to obtain product one. The product one is scraped towards the bottom of the cone of the static thickening tank 2 by a sludge scraper. The outlet of the static thickening tank 2 is connected to the inlet of the flora cultivation tank 3.

[0023] In this embodiment, after the product one is introduced into the microbial community culture device 3, by heating, stirring the slurry in the microbial community culture device 3, and performing external circulation of the slurry, the temperature of the slurry in the microbial community culture device 3 is maintained at 30°C to 36°C to obtain the product two. At this time, the biogas generated by the digestion tank needs to be led to the culture tank 3-1 to ensure an anaerobic environment. Specifically, the microbial community culture device 3 is composed of a culture tank body 3-1, a first slurry pump 3-2, a first temperature detector 3-3, a first water outlet valve 3-4, a slurry circulation pump 3-5, and a culture tank stirrer 3-6. The culture tank 3-1 is a sealed structure, and the sealing gas is the biogas generated by the digestion tank. Inside the culture tank 3-1, several groups of temperature measuring devices are evenly arranged along the pool wall for measuring the temperature of the slurry in the culture tank 3-1. A heating coil 3-7 is installed at the bottom of the culture tank 3-1. The inlet of the heating coil 3-7 is connected to the hot water pump 9-10, and the outlet is connected to the cold water tank 9-11 through the first temperature detector 3-3 and the first water outlet valve 3-4 installed on the pipeline. The hot water generated by the alkali solution preparation device 9 enters the heating coil 3-7 to heat the slurry in the culture tank 3-1. After heat exchange, the cold water discharged from the heating coil 3-7 is circulated into the alkali solution preparation device 9 for continuous heating, realizing the recycling of heat and water. A slurry circulation pump 3-5 is arranged outside the culture tank 3-1, and a culture tank stirrer 3-6 is arranged on the upper part of the culture tank 3-1. The slurry circulation pump 3-5 is used to transport the slurry at the bottom of the culture tank 3-1 to the top of the culture tank 3-1. The culture tank stirrer 3-6 makes the temperature of the slurry in the tank uniform by stirring. The outlet of the culture tank 3-1 is connected to the inlet of the mixing tank 10 through the first slurry pump 3-2 installed on the pipeline, and the fermented slurry is transported to the mixing tank 10. The mixing tank 10 is connected to the inlet of the second grinder 11 through a pump installed on the pipeline, and the outlet of the second grinder 11 is connected to the inlet of the slurry hot water exchanger 12.

[0024] The outlet of the coagulation device 4 is connected to the inlet of the first grinder 5. Specifically, the coagulation device 4 is composed of a screw conveyor 4-1, a flocculant preparation tank 4-2, a flocculant stirrer 4-3, a first water pump 4-4, a first water tank 4-5, a flocculant supply pump 4-6, a coagulation tank body 4-7, and a second slurry pump 4-8. The flocculant is fed into the flocculant preparation tank 4-2 through the screw conveyor 4-1. Several groups of flocculant stirrers 4-3 are arranged in the flocculant preparation tank 4-2. The first water tank 4-5 is connected to the flocculant preparation tank 4-2 through the first water pump 4-4 installed on the pipeline. The outlet of the flocculant preparation tank 4-2 is connected to the coagulation tank 4-7 through the flocculant supply pump 4-6 installed on the pipeline. The slurry two is introduced into the coagulation tank 4-7 and precipitates and cakes under the action of the flocculant to complete primary dehydration. The outlet of the coagulation tank 4-7 is connected to the inlet of the first grinder 5 through the second slurry pump 4-8 installed on the pipeline.

[0025] The outlet of the first grinder 5 is connected to the inlet of the centrifuge 6, and the outlet of the centrifuge 6 is connected to the inlet of the aerobic device 7. The product is subjected to an aerobic reaction in the aerobic device 7, and oxygen is supplied to the aerobic device 7 to increase the growth rate of aerobic organisms. Specifically, the aerobic device 7 is composed of a ventilator 7-1, an air duct 7-2, a branch pipe 7-3, and an aerobic pond 7-4. The lower part of the aerobic pond 7-4 is a V-shaped chamber, and the upper part is a rectangular chamber, and the top of the aerobic pond 7-4 is open. An air duct 7-2 is provided at the top of the aerobic pond 7-4, and the air duct 7-2 is connected to the ventilator 7-1. The ventilator 7-1 supplies oxygen into the aerobic pond 7-2. The branch pipes 7-3 extending into the aerobic pond 7-4 are vertically arranged at intervals of 50 cm on the air duct 7-2, and air outlet holes are uniformly processed on the branch pipes 7-3, and oxygen is supplied into the aerobic pond 7-4 through the air outlet holes.

[0026] The outlet of the aerobic device 7 is connected to the inlet of the lye regulating device 8, and the lye regulating device 8 is supplied with lye by the lye preparation device 9. Specifically, the lye preparation device 9 is composed of a cold water heating tank 9-1, a lime reaction tank 9-2, a lye preparation stirrer 9-3, a second water pump 9-4, a second water tank 9-5, a lye pump 9-6, a second temperature detector 9-7, a second water outlet valve 9-8, a hot water tank 9-9, a hot water pump 9-10, a cold water tank 9-11, and a cold water pump 9-12. The material of the lime reaction tank 9-2 is aluminum plastic steel with good heat dissipation effect. A lye preparation stirrer 9-3 is arranged inside the lime reaction tank 9-2. The second water tank 9-5 is connected to the inlet of the lime reaction tank 9-2 through the second water pump 9-4 installed on the pipeline. The outlet of the lime reaction tank 9-2 is connected to the lye regulating device 8 through the lye pump 9-6 installed on the pipeline. A cold water heating tank 9-1 is concentrically arranged outside the lime reaction tank 9-2. Heat insulation materials are wound around the cold water heating tank 9-1 to prevent heat loss. A second temperature detector 9-7 is arranged at the bottom of the cold water heating tank 9-1. The water in the cold water tank 9-11 enters the upper part of the interlayer formed by the cold water heating tank 9-1 and the lime reaction tank 9-2 through the cold water pump 9-12. The lower part of the interlayer formed by the cold water heating tank 9-1 and the lime reaction tank 9-2 is connected to the inlet of the hot water tank 9-9 through the first water outlet valve 9-8 installed on the pipeline. The outlet of the hot water tank 9-9 is connected to the inlet of the flora cultivation device 3 through the hot water pump 9-10 installed on the pipeline. The inlet of the cold water tank 9-11 is connected to the outlet of the flora cultivation device 3. Quicklime and water are added into the lime reaction tank 9-2, a large amount of heat released by the addition of quicklime and water is recovered, lye and hot water are obtained. The lye flows into the lye regulating device 8, and the hot water flows into the heating coil 3-7 to provide heat for the cultivation pond 3-1. After the hot water exchanges heat and cools down, it continues to flow to the cold water tank 9-11 for heating and is recycled.

Claims

1. A sludge pretreatment device for anaerobic digestion in a digester of a municipal sewage plant, characterized by: The slurry is introduced into the slurry distribution tank (1). The outlet of the slurry distribution tank (1) is connected to the inlet of the static concentration tank (2) through a pump installed on the pipeline, and is connected to the inlet of the condensation device (4) through another pump installed on the pipeline. The outlet of the static concentration tank (2) is connected to the inlet of the bacterial colony culture device (3). The outlet of the bacterial colony culture device (3) is connected to the inlet of the mixing tank (10). The alkali solution preparation device (9) supplies hot water to the bacterial colony culture device (3). The cold water after circulating and cooling returns to the alkali solution preparation device (9). The mixing tank (10) is installed The pump on the pipeline is connected to the inlet of the second grinder (11), the outlet of the second grinder (11) is connected to the inlet of the mud hot water exchanger (12), the outlet of the coagulation device (4) is connected to the inlet of the first grinder (5), the outlet of the first grinder (5) is connected to the inlet of the centrifuge (6), the outlet of the centrifuge (6) is connected to the inlet of the aerobic device (7), the outlet of the aerobic device (7) is connected to the inlet of the alkali liquid regulating device (8), and the alkali liquid regulating device (8) is supplied with alkali liquid by the alkali liquid preparation device (9).

2. The anaerobic digestion sludge pretreatment device for the digester of the municipal sewage plant according to claim 1 is characterized in that The alkali solution preparation device (9) comprises: an alkali preparation stirrer (9-3) is arranged inside a lime reaction tank (9-2); a second water tank (9-5) is connected to the inlet of the lime reaction tank (9-2) via a second clean water pump (9-4) installed on a pipeline; the outlet of the lime reaction tank (9-2) is connected to the alkali solution regulating device (8) via an alkali solution pump (9-6) installed on a pipeline; a cold water heating tank (9-1) is concentrically arranged outside the lime reaction tank (9-2); a second temperature detector (9-7) is arranged at the bottom of the cold water heating tank (9-1); The water in the water tank (9-11) enters the upper part of the interlayer formed by the cold water heating tank (9-1) and the lime reaction tank (9-2) through the cold water pump (9-12); the lower part of the interlayer formed by the cold water heating tank (9-1) and the lime reaction tank (9-2) is connected to the inlet of the hot water tank (9-9) through a second water outlet valve (9-8) installed on the pipeline; the outlet of the hot water tank (9-9) is connected to the inlet of the bacterial colony culture device (3) through the hot water pump (9-10) installed on the pipeline; and the inlet of the cold water tank (9-11) is connected to the outlet of the bacterial colony culture device (3).

3. The anaerobic digestion sludge pretreatment device for the digester of the municipal sewage plant according to claim 1 is characterized in that The bacterial colony culture device (3) comprises: a culture tank (3-1) of a sealed structure; a heating coil (3-7) is arranged at the bottom of the culture tank (3-1); the inlet of the heating coil (3-7) is connected to a hot water pump (9-10); the outlet of the heating coil (3-7) is connected to a cold water tank (9-11) via a first temperature detector (3-3) and a first water outlet valve (3-4) installed on a pipeline; a mud circulation pump (3-5) is arranged outside the culture tank (3-1); a culture tank agitator (3-6) is arranged on the top of the culture tank (3-1); and the outlet of the culture tank (3-1) is connected to the inlet of a mixing tank (10) via a first mud pump (3-2) installed on a pipeline.

4. The anaerobic digestion sludge pretreatment device for the digester of the municipal sewage plant according to claim 1 is characterized in that The aerobic device (7) comprises: an air duct (7-2) is arranged on the top of the aerobic pool (7-4), the air duct (7-2) is connected to the ventilator (7-1), branch pipes (7-3) extending into the aerobic pool (7-4) are vertically arranged on the air duct (7-2) at intervals of 50 cm, and the branch pipes (7-3) are evenly distributed with air outlet holes.

5. The anaerobic digestion sludge pretreatment device for the digester of the municipal sewage plant according to claim 4, characterized in that: The lower part of the aerobic pool (7-4) is a V-shaped chamber, the upper part is a rectangular chamber, and the top of the aerobic pool (7-4) is open.

6. The anaerobic digestion sludge pretreatment device for the digester of the municipal sewage plant according to claim 1, characterized in that The coagulation device (4) is as follows: the flocculant is fed into the flocculant preparation tank (4-2) through a screw conveyor (4-1); a plurality of flocculant agitators (4-3) are arranged in the flocculant preparation tank (4-2); the first water tank (4-5) is connected to the flocculant preparation tank (4-2) through a first clean water pump (4-4) installed on a pipeline; the outlet of the flocculant preparation tank (4-2) is connected to the coagulation tank (4-7) through a flocculant supply pump (4-6) installed on a pipeline; the mud is introduced into the coagulation tank (4-7) to precipitate and agglomerate; the outlet of the coagulation tank (4-7) is connected to the inlet of the first grinder (5) through a second mud pump (4-8) installed on a pipeline.

7. The anaerobic digestion sludge pretreatment device for the digester of the municipal sewage plant according to claim 1 is characterized by: A sludge scraper is provided at the lower part of the static concentration tank (2).

Images