CN216639147U - Process system for efficiently and stably removing suspended substances in biogas slurry - Google Patents

Abstract

A process system for efficiently and stably removing suspended matters in biogas slurry comprises a biogas slurry pool, an efficient snail stacking dehydration device connected with the biogas slurry pool, a sewage pool connected with the snail stacking dehydration device, a PAC dosing device and a PAM dosing device; the spiral shell stacking dehydration device comprises a stirring and mixing box and a spiral shell stacking dehydration machine which are connected with each other; the stirring and mixing box is respectively connected with a PAC dosing device, a PAM dosing device and a biogas slurry pool; the spiral shell overlapping dehydrator is provided with a water outlet and a sludge outlet, and the water outlet is connected with the sewage tank. The low-energy and high-efficiency solid-liquid separation is realized through the gradual change thread pitch of the spiral-stacked dehydrator; the two flocculating agents are adopted for flocculation separation of the biogas slurry, so that the deslagging rate of biogas slurry treatment is improved; the automatic flushing pipeline is added to the screw stacking dehydrator, so that the running stability of the system is obviously improved. The utility model has the beneficial technical effects of low energy consumption, high deslagging rate and good system operation stability.

Description

Process system for efficiently and stably removing suspended substances in biogas slurry

Technical Field

The utility model belongs to the field of environment-friendly equipment, and particularly relates to a process system for efficiently and stably removing suspended substances in biogas slurry.

Background

The prior art adopts the processes of sedimentation tank gravity sedimentation, horizontal screw centrifuge separation, screw extrusion type solid-liquid separator and the like.

The gravity sedimentation process of the sedimentation tank has poor effect of removing suspended matters, large floor area, high construction cost, high water content of the settled sludge, secondary treatment, high secondary treatment cost of the settled sludge and difficulty in efficiently removing the suspended matters in the biogas slurry.

The horizontal screw centrifuge separation process has a good effect of removing suspended matters, but the equipment has high requirements on the stability of the biogas slurry, is unstable in operation, has high equipment investment cost, high power load, high operation and maintenance cost and low automation degree, and is difficult to stably remove the suspended matters in the biogas slurry.

The spiral extrusion type solid-liquid separator has the advantages of poor effect of removing suspended matters, unstable equipment slag discharge, high precision requirements of spiral and screen meshes, direct influence on water outlet effect due to slight abrasion, high failure rate, low automation degree and difficulty in stable production in actual production.

In conclusion, the existing process system for removing the suspended substances in the biogas slurry has the problems of low deslagging rate, high energy consumption and poor stability.

SUMMERY OF THE UTILITY MODEL

The utility model aims to solve the problems of low deslagging rate, high energy consumption and poor stability of the conventional process system for removing suspended substances in biogas slurry.

In order to solve the problems, the utility model provides a process system for efficiently and stably removing suspended matters in biogas slurry, which comprises a biogas slurry pool, an efficient spiral shell stacking dehydration device connected with the biogas slurry pool, a sewage pool connected with the spiral shell stacking dehydration device, a PAC dosing device and a PAM dosing device; the spiral shell stacking dehydration device comprises a stirring and mixing box and a spiral shell stacking dehydration machine which are connected with each other; the stirring and mixing box is respectively connected with a PAC dosing device, a PAM dosing device and a biogas slurry pool; the spiral shell overlapping dehydrator is provided with a water outlet and a sludge outlet, and the water outlet is connected with the sewage tank.

The PAC dosing device comprises a PAC dissolving box, a PAC liquid level sensor, a PAC dissolving stirrer, a PAC dosing pump and a dosing pipeline which is connected with the PAC dissolving box and is provided with a PAC dosing valve; the PAC water adding valve and the PAC liquid level sensor are automatically controlled in a linkage mode so as to realize automatic water supplement of the PAC medicine dissolving box; PAC adds the automatic antithetical couplet of medicine pump and PAC level sensor and controls, realizes carrying the PAC medicament automatically to the pipeline mixer that sets up on the natural pond liquid pipeline according to the liquid level of PAC dissolves the medical kit, makes it and natural pond liquid intensive mixing reaction.

The PAM dosing device comprises a PAM dissolving medicine box, a PAM liquid level sensor, a medicine feeding machine connected with the PAM dissolving medicine box, a dosing pipeline connected with the PAM dissolving medicine box and provided with a PAM dosing valve, and a PAM dosing pump connected with the PAM dissolving medicine box; the PAM dosing pump is automatically and jointly controlled by a liquid level meter in the PAM dissolving medicine box, and automatically conveys PAM medicines into the stirring and mixing box to react with sludge according to the liquid level condition of the PAM dissolving medicine box; PAM adds water valve and PAM level sensor automatic joint control in order to realize PAM dissolves the automatic water supply of medicine case.

The spiral shell stacking dehydrator comprises a built-in variable-pitch spiral shaft, the variable-pitch spiral shaft comprises a concentration section and a dehydration section, the biogas slurry enters the spiral shell stacking dehydrator and then enters the concentration section to be concentrated, and filtrate is filtered out from the periphery; the spiral pitch from the concentration section to the dehydration section gradually becomes smaller, and suspended matters in the concentration section are conveyed forward along with the spiral and are extruded until sludge which is pressed dry is formed at a spiral outlet; the spiral shell overlapping dehydrator is further connected with an automatic flushing pipeline, and an electric valve connected with a controller is arranged on the automatic flushing pipeline to realize timed automatic flushing.

Collecting the fermented biogas slurry into a biogas slurry pool, and arranging a submersible stirrer in the pool to fully mix the biogas slurry to ensure that the concentration gradient of the biogas slurry in the pool is within 0.5%; conveying the mixed biogas slurry to a stirring and mixing box through a biogas slurry pump, fully mixing and reacting the biogas slurry with two flocculants, namely PAM and PAC, and overflowing the mixture into a stack screw dehydrator for dehydration; the extruded sludge is automatically discharged through a sludge outlet, and the filtered filtrate is cached in a filtrate box at the bottom of the dehydrator and automatically flows into a sewage tank through a water outlet and a pipeline for temporary storage; a sewage pump is arranged in the sewage pool and is automatically discharged and utilized according to the liquid level condition in the pool.

The spiral-stacked dehydrator is used for compressing flocculated biogas slurry in a variable-pitch segmented component manner, low-speed spiral replaces high-speed centrifugal motion to reduce energy consumption, and two-stage variable-pitch is used for carrying out step-by-step solid-liquid separation and compression to improve separation efficiency, so that low-energy and high-efficiency solid-liquid separation is realized; the two flocculating agents are adopted to carry out flocculation separation on the biogas slurry, so that the deslagging rate of biogas slurry treatment is improved; and an automatic flushing pipeline is added to the screw stacking dehydrator, so that the equipment failure rate is reduced, and the stability of system operation is obviously improved.

In conclusion, the utility model has the beneficial technical effects of low energy consumption, high slag removal rate and good system operation stability.

Drawings

FIG. 1 is a schematic structural view of the present invention;

in the figure: 1. a biogas slurry pool; 2. a sewage tank; 3. a high-efficiency spiral shell stacking dehydration device; 4, PAM dosing device; PAC dosing device; 1-1, a biogas pump; 1-2, a submersible mixer; 2-1, a sewage pump; 3-1, stacking a spiral dehydrator; 3-2, stirring and mixing the mixture in a mixing box; 3-3, a sludge outlet; 3-4, a filtrate tank; 3-5, water outlet; 4-1, PAM dosing pump; 4-2, dissolving a medicine box by using PAM; 4-3, feeding a medicine machine by PAM; 4-4, a water feeding pipeline; PAC dosing pump; 5-2.PAC dissolving box; 5-3, a liquid level sensor; 5-4. a medicine dissolving stirrer; 5-5, a water feeding pipeline.

Detailed Description

The following further description of the embodiments with reference to fig. 1 and the specific embodiments is provided to facilitate the understanding of the present invention.

As shown in fig. 1, a process system for efficiently and stably removing suspended solids in biogas slurry comprises a biogas slurry tank 1, an efficient snail stacking dehydration device 3 connected with the biogas slurry tank 1, a sewage tank 2 connected with the snail stacking dehydration device 3, a PAM dosing device 4 and a PAC dosing device 5; the spiral shell stacking dehydration device 3 comprises a stirring and mixing box 3-2 and a spiral shell stacking dehydration machine 3-1 which are connected with each other; the stirring and mixing box 3-2 is respectively connected with a PAM dosing device 4, a PAC dosing device 5 and a biogas slurry pool 1; the spiral shell overlapping dehydrator 3-1 is provided with a water outlet 3-5 and a sludge outlet 3-3, and the water outlet 3-5 is connected with the sewage tank 2.

Collecting fermented biogas slurry into the biogas slurry pool 1, wherein a submersible stirrer 1-2 is arranged in the biogas slurry pool 1 to fully mix the biogas slurry, so that the concentration gradient of the biogas slurry in the biogas slurry pool 1 is within 0.5%; conveying the uniformly mixed biogas slurry to a stirring and mixing box 3-2 through a biogas slurry pump 1-1, fully mixing and reacting the biogas slurry with a flocculating agent, and overflowing the biogas slurry into a spiral shell overlapping dehydrator 3-1 for dehydration; the extruded sludge is automatically discharged through a sludge outlet 3-3, and the filtered filtrate is cached in a filtrate tank 3-4 at the bottom of the spiral-wound water extractor 3-1 and automatically flows into a sewage tank 2 for temporary storage through a water outlet and a pipeline 3-5; a sewage pump 2-1 is arranged in the sewage pool 2 and is automatically discharged for utilization according to the liquid level condition in the sewage pool 2.

A set of radar liquid level sensor 1-3 is arranged at the top of the biogas liquid pool 1, so that the liquid level in the pool is monitored in real time, and the liquid level in the pool and the biogas liquid pump 1-1 automatically control and operate in a linkage manner, so that the biogas liquid pump 1-1 is ensured to be started and stopped automatically according to the liquid level condition in the pool; the submersible mixer 1-2 is started and stopped along with the start and stop of the biogas pump 1-1, and is realized through a PLC automatic control program: starting the submersible stirrer 1-2 5min before starting the biogas pump 1-1, and stopping the submersible stirrer 1-2 after stopping the biogas pump 1-1 to ensure that biogas slurry in the tank is fully mixed and the concentration of the biogas slurry is relatively stable when starting the biogas pump 1-1.

The top of a stirring and mixing box 3-2 at the front end of the spiral-wound water extractor 3-1 is provided with an overflow port, redundant biogas slurry flows back to a biogas slurry pool through the overflow port to ensure the continuous and stable operation of the whole system, the spiral-wound water extractor 3-1 is provided with an independent PLC automatic control system, the linkage control is realized with a biogas pump 1-1 at the front end through a PIC program, the biogas pump 1-1 is started for 30s before starting, and the spiral-wound water extractor 3-1 is started through signal transmission; stopping the methane pump 1-1 for 1min, and stopping the spiral-overlaying dehydrator 3-1.

A set of radar liquid level sensor 2-2 is arranged on the top of the sewage pool 2, the liquid level in the pool is monitored in real time, and the radar liquid level sensor and the sewage pump 2-1 automatically control and operate in a linkage mode, so that the sewage pump can be guaranteed to stop automatically according to the situation that the liquid level in the pool is high, low and high.

The biogas liquid pool 1 is of a reinforced concrete structure, the shape of the pool is round or octagonal so as to ensure uniform mixing during stirring, no dead angle during stirring, the depth of the pool is 4-6 meters so as to ensure the effective water depth in the pool, and the retention time is longer than 4 hours so as to ensure that the subsequent process equipment is stable and needs to operate at present.

1-2 of the submersible mixer, the model number of QJB2.2/8-320/3-740C/S, the power of 2.2KW, the rotating speed of 740r/min, the diameter of a blade of 320mm and the axial thrust of 582N; the impeller is compact in structure, simple in installation and operation and convenient to maintain, and the sweepback blades of the impeller have a self-cleaning function and can prevent impurities, wind and blockage.

The biogas pump 1-1 adopts a submersible sewage pump with model of WQR25-12-2.2 and flow rate of 25m³H, the lift is 12m, the power is 2.2KW, and the particle diameter is 40 mm; the impeller is blocked by a large-channel single-blade pit, the impeller is anti-blocked and anti-winding, and the blades are attached with hard alloy cutter heads, so that large torn particles and long fiber sundries can be cut.

The marsh liquid after the reaction is through in pipeline overflow to fold spiral shell hydroextractor 3-1, its inside includes: the device comprises a rack, a variable-pitch spiral shaft, a movable ring, a static ring, a spacer ring and a stud bolt; the biogas slurry firstly enters a concentration section, when a variable-pitch spiral shaft rotates, multiple fixed-movable lamination sheets arranged on the periphery of a pushing shaft relatively move, and water is filtered out from the lamination sheet gaps which relatively move under the action of gravity, so that rapid concentration is realized; then the sludge enters a dewatering section formed by gradually reducing gaps among the variable-pitch screw shaft, the fixed ring and the movable ring, and the concentrated sludge continuously moves forwards along with the rotation of the variable-pitch screw shaft; along the outlet direction of the mud cake, the pitch of the variable pitch screw shaft is gradually reduced, the gap between the rings is also gradually reduced, and the volume of the screw cavity is continuously contracted; under the action of the back pressure plate at the outlet, the internal pressure is gradually enhanced, the water in the sludge is extruded and discharged under the sequential continuous operation and pushing of the variable-pitch screw shafts, the solid content of the filter cake is continuously increased, and the continuous dehydration of the sludge is finally realized.

When the screw-stacking dehydrator 3-1 is stopped, cleaning the variable-pitch screw shaft, the fixed ring and the movable ring in the main machine through a self-cleaning device; the self-cleaning principle: the variable-pitch screw shaft rotates to push the movable ring to rotate continuously, and the equipment realizes a continuous self-cleaning process by moving between the fixed ring and the movable ring, so that the problem of blockage is effectively avoided, and the stability of continuous operation of the system is obviously enhanced.

The screw-stacking dehydrator 3-1 is made of a full stainless steel material, and a wear-resistant layer is arranged on the surface layer of the variable-pitch screw shaft to slow down the abrasion of the variable-pitch screw shaft; the screw shaft with variable pitch, the concentration section and the dehydration section are integrated, so that the structure is compact and the occupied area is small; the driving part adopts a speed reducer to be directly connected and a variable frequency motor for the speed reducer; the fixed ring sheet and the movable ring sheet form a cylindrical filter body to improve the filtering efficiency.

The extruded sludge is discharged through a sludge outlet 3-3, and the filtered filtrate is cached in a built-in filtrate box 3-4 of the spiral-wound water extractor 3-1 and automatically flows into a sewage tank for temporary storage through a water outlet 3-5 and a pipeline.

The process is matched with two flocculation dosing devices, one is a polymeric flocculant Polyacrylamide (PAM), and the organic macromolecules can flocculate solid particles into clusters, so that the solid particles sink, and supernatant is colorless and transparent; the other is an inorganic polymeric flocculant poly ferric chloride (PAC) which forms a net structure in water and can bond small solid particles in the wastewater together; the flocculation performance can be obviously improved by the action of the two.

PAM charge device 4 adopts three box integrated charge devices, and it includes: 4-3 parts of a PAM medicine feeding machine, 4-2 parts of a PAM dissolving box, 4-1 parts of a PAM medicine feeding pump and 4-4 parts of a water feeding pipeline with an electric control valve.

PAM medicament is automatically added into a PAM medicament dissolving tank 4-2 at a constant speed through a PAM medicament feeder 4-3, automatic water replenishing is realized through an electric valve on a water charging pipeline 4-4 and an automatic joint control design of a liquid level sensor in the device, and the PAM medicament is stably fed through the PAM medicament feeder 4-3The dosage of the medicine is 2000g/h, and the automatic water replenishing amount is 1m³H; according to the liquid level condition in the liquid level sensor real-time supervision charge device to guarantee charge device steady continuous operation. PAM is rapidly mixed with water and cured under the action of a stirrer arranged in a PAM medicine dissolving box 4-2; through the automatic joint control design of the PAM dosing pump 4-1 and a liquid level sensor in the device, cured medicaments are automatically conveyed into a stirring and mixing box 3-2 at the front end of a laminated spiral dewatering machine 3-1 to be fully mixed and reacted with biogas slurry according to the liquid level condition of the PAM medicament dissolving box 4-2.

The PAM medicine feeder 4-3 is made of 304 stainless steel, the power of the PAM medicine feeder is 0.37kw, and the PAM medicine feeder feeds medicine into a medicine dissolving box at a constant speed and a fixed quantity through a conveying screw.

The PAM medicine dissolving box 4-2 is a three-box medicine dissolving box, is made of 304 stainless steel materials, has the outer dimension of 2400mm multiplied by 1200mm multiplied by 1180mm, is uniformly divided into a front section, a middle section and a rear section by a partition board, is automatically fed into the front box from the top by a PAM medicine feeder, is communicated with an opening at the bottom of the front box, is communicated with an opening at the top of the rear box, and is provided with a medicine outlet at the bottom of the rear box, so that the medicines are baffled up and down in the three boxes, and the medicines are fully mixed with water and cured. The front box, the middle box and the rear box are respectively internally provided with a vertical shaft stirrer, and the power of the vertical shaft stirrer is 0.75 kw; the material in the box is 304 stainless steel; the water replenishing electromagnetic valve is DN50 and is made of 304 stainless steel; the liquid level sensor adopts a diaphragm type pressure sensor, and the power distribution control box adopts an independent PLC control system. The whole system can be intelligently controlled by a PLC (programmable logic controller), and the automation degree is high; the device is highly integrated, small in size, simple to operate and convenient to install; when equipment fails, the system can be automatically closed and simultaneously sends out an alarm signal; the performance is stable, and the adding amount of the dry powder can be automatically adjusted according to the change of water flow; the corrosion resistance is good, and the contact part with the medium is made of stainless steel.

PAM dosing pump adopts a screw pump, the model: g25-01, flow 2m³H, lift of 12m, power of 1.5KW, rotating speed of 960r/min, the rotor made of stainless steel and the stator made of nitrile rubber; the spiral shaft pump belongs to a rotor type positive displacement pump, has good adaptability to conveying high-viscosity medium PAM flocculant and can not damage the medicineThe agent has the advantages of inherent structure, stable flow and stable pressure.

The PAC dosing device 5 adopts a barrel type dosing device and comprises a PAC dosing pump 5-1, a PAC dissolving box 5-2, a liquid level sensor 5-3 and a dissolving stirrer 5-4.

PAC medicament is regularly put into a PAC medicament dissolving box 5-2, automatic water replenishing is realized through the automatic joint control design of an electric valve on a water adding pipeline 5-5 and a liquid level sensor 5-3, the PAC medicament is regularly dosed in batches mechanically, the dosage is 250 kg/batch, and the automatic water replenishing amount is 5m³(ii)/batch; the liquid level condition in the PAC dosing device 5 is monitored in real time according to the liquid level sensor 5-3 so as to ensure the stable and continuous operation of the PAC dosing device 5.PAC is rapidly mixed with water under the action of a medicine dissolving stirrer 5-4 arranged in a PAC medicine dissolving box 5-2, and PAC medicines are conveyed into a pipeline mixer 3-6 arranged on a biogas slurry pipeline according to the liquid level condition of the PAC medicine dissolving box 5-2 through the automatic joint control design of a PAC medicine adding pump 5-1 and a liquid level sensor 5-3, so that the PAC medicines and the biogas slurry are fully mixed and reacted.

The PAC dosing device 5 and the PAM dosing device 4 are respectively provided with an independent PLC automatic control system, the whole automatic control of the whole process system is realized in a signal communication mode with a main line control system, the PAC dosing pump 5-1 and the PAM dosing pump 4-1 are started and stopped simultaneously with the biogas pump 1-1, and when any one of the PAC dosing pump 5-1 and the PAM dosing pump 4-1 cannot be started due to reasons in the device, the biogas pump 1-1 and the dehydrator device 3 are not started or stopped when the biogas pump 1-1 and the dehydrator device 3 are stopped.

The PAC medicine dissolving box is made of PE material, the size is phi 1800mm multiplied by 2000mm, the top is provided with a medicine adding hole, and the bottom is provided with a medicine outlet; a vertical shaft stirrer and a double-layer paddle are arranged in the PAC drug dissolving box, the power is 1.5kw, and the material in the box is 304 stainless steel; the water replenishing electromagnetic valve is DN50 and is made of 304 stainless steel; the liquid level sensor is a diaphragm type pressure sensor; the power distribution control box is an independent PLC control system. The PAC dosing device 5 has high automation degree, and the whole system can be intelligently controlled by a PLC; the device is highly integrated, small in size, simple to operate and convenient to install; when equipment fails, the system can be automatically closed and simultaneously sends out an alarm signal; the corrosion resistance is good, the barrel-type dissolving medicine box is made of PE materials, and the paddle and the shaft at the contact position of the bucket and the medium are made of stainless steel materials.

The PAC dosing pump 5-1 adopts a spiral shaft pump, and has the following model: g25-01, flow 2m³H, lift 12m, power 1.5KW, rotating speed 960r/min, rotor stainless steel and stator nitrile rubber; the spiral shaft pump belongs to a rotor type displacement pump, has good adaptability to conveying media, does not damage the inherent structure of the medicament, and has stable flow and stable pressure.

In the biogas slurry pretreatment and debugging period, the running conventional spiral shell-folding dehydrator is difficult to ensure stable sludge discharge and high water content; because the conventional spiral-wound laminated dehydrator is mainly used for dehydrating biochemical sludge with very small granularity and characters, and the components of suspended matters in the biogas slurry are very complex and mainly comprise sludge particles, short fibers and undigested feed, and the particle size of the suspended matters is larger and more complex than that of the biochemical sludge; according to the characteristics of suspended matters in the biogas slurry, after the biogas slurry is communicated with equipment manufacturers, the problems of unstable sludge discharge and high sludge water content are solved through the improvement of the pitch spacing of the spiral shaft of the 3-1 spiral-shaft overlapping screw dehydrator for many times.

The spiral-stacked dehydrator 3-1 is divided into two parts, namely a concentration part and a dehydration part, biogas slurry enters the separator spiral, enters the concentration part spiral to be concentrated, and filtrate is filtered from the periphery; the spiral pitch from the concentration part to the dewatering part is gradually reduced, and suspended matters in the concentration part are conveyed forward along with the spiral and are extruded until sludge at the spiral outlet is extruded out.

Because the sludge discharge is unstable and the water content is high in the actual operation process, the screw pitch at the spiral feed inlet of the concentration part of the spiral-stacked dehydrator is adjusted to be 20mm smaller, the screw pitch at the spiral discharge outlet of the dehydration part is adjusted to be 20mm larger, and the screw pitch of the whole spiral from the feed inlet to the sludge discharge outlet is adjusted to be uniform and gradually smaller; the average data comparison of one week before and after the improvement is detailed in the following table: the screw pitch of the feed port end of the original screw shaft is 215mm, and the screw pitch of the discharge port end is 90 mm; the screw pitch of the feed port end of the improved variable-pitch screw shaft is 195mm, and the screw pitch of the discharge port end is 110 mm.

Description of the data: before improvement, the concentration TS of suspended matters in the original biogas slurry is 2.43 percent, the concentration TS of suspended matters in the separated filtrate is 1.22 percent, the removal rate of the suspended matters is (2.43-1.22)/2.43 is 49.79 percent, and the solid content TS of the dewatered sludge is 19.20 percent.

After improvement, the concentration TS of suspended matters in the original biogas slurry is 2.48 percent, the concentration TS of suspended matters in the separated filtrate is 1.05 percent, the removal rate of the suspended matters is (2.48-1.05)/2.48 is 57.66 percent, and the solid content TS of the dewatered sludge is 20.30 percent.

Comparison of the data before and after improvement demonstrates that: the removal rate of suspended substances after improvement is 7.87 percent points higher than that before improvement, the solid content of the dewatered sludge after improvement is 1.1 percent points higher than that before improvement, and the separation effect after improvement is obviously better than that before improvement.

In the implementation and operation process of the process, the principle of dehydrating the medicament is also important, whether the medicament is selected properly or not, and the medicament cost and the treatment effect are directly influenced by the adding amount and the proportion of the PAC and the PAM; experiments on a large number of different types of medicaments are carried out in the debugging process, and the experimental data are as follows:

table 1 purpose of the experiment: in order to verify the effect of polyaluminium chloride PAC and 20-ionic-degree polyacrylamide PAM as flocculating agents on biogas slurry dehydration.

From the experimental data it can be seen that: when the polyaluminium chloride PAC dissolution concentration is 5%, the dosage of the medicine to be added into 1 ton of biogas slurry is 30L, the dosage is 1500g, and the medicine cost is 3 yuan/ton of biogas slurry; when the dissolution concentration of 20-ionic Polyacrylamide (PAM) is 0.2%, the dosage of the drug to be added to 1 ton of biogas slurry is 50L, the dosage is 100g, and the drug cost is 2 yuan/ton of biogas slurry; the two kinds of flocculant react with marsh liquid and are dewatered in a screw stacking machine, the content TS of suspended matter in the effluent is 1.02%, and the solid content TS of the sludge is 20.3%.

Table 2 purpose of the experiment: in order to verify the effect of polyferric chloride PAC and 20-ionic-degree polyacrylamide PAM as flocculating agents on biogas slurry dehydration.

From the experimental data it can be seen that: when the polymeric ferric chloride PAC dissolution concentration is 5%, the dosage of the medicine to be added into 1 ton of biogas slurry is 30L, the dosage is 1500g, and the medicine cost is 3 yuan/ton of biogas slurry; when the dissolution concentration of 20-ionic Polyacrylamide (PAM) is 0.2%, the dosage of the drug to be added to 1 ton of biogas slurry is 50L, the dosage is 100g, and the drug cost is 2 yuan/ton of biogas slurry; the two flocculants react with the biogas slurry together and are dehydrated by a screw stacking machine, the content TS of suspended matters in the effluent is 1.44%, and the solid content TS of the sludge is 18.5%.

The comparison of the experimental data in table 1 and table 2 shows that: on the premise of determining that 20-degree-of-ion polyacrylamide is selected as PAM, the PAC selects polyaluminum chloride to be lower than 0.42 percent of the effluent suspended matter content of polyferric chloride, and the solid content of the sludge is higher than 1.8 percent; therefore, the process determines PAC to be polyaluminum chloride.

Table 3 purpose of the experiment: in order to verify the effect of polyaluminium chloride PAC and 30-ionic-degree polyacrylamide PAM (polyacrylamide) as flocculating agents on biogas slurry dehydration.

From the experimental data it can be seen that: when the polyaluminium chloride PAC dissolution concentration is 5%, the dosage of the medicine to be added into 1 ton of biogas slurry is 30L, the dosage is 1500g, and the medicine cost is 3 yuan/ton of biogas slurry; when the dissolution concentration of the 30-ionic-degree polyacrylamide PAM is 0.2%, the dosage of the drug to be added to 1 ton of biogas slurry is 50L, the dosage is 100g, and the drug cost is 2.5 yuan/ton of biogas slurry; the two kinds of flocculating agents react with the biogas slurry together and are dehydrated by a screw stacking machine, the content TS of suspended matters in the effluent is 1.01 percent, and the solid content TS of the sludge is 20.3 percent.

The experimental data in table 1 and table 3 show that: under the premise of determining that polyaluminium chloride is selected by PAC, the content phase of suspended matters in effluent of 20-ionic polyacrylamide and 30-ionic polyacrylamide which are selected by PAM is more than 0.01 percentage point, the solid content of the effluent is the same, and the treatment cost of 1 ton of biogas slurry is 0.5 yuan lower than that of 30-ionic polyacrylamide which is selected by 20-ionic polyacrylamide, so that the process determines that 20-ionic polyacrylamide is selected by PAM.

Table 4 purpose of experiment: in order to verify the influence of different adding amounts on the biogas slurry dehydration effect when polyaluminum chloride PAC and 20-ionic-degree polyacrylamide PAM medicament are used as flocculating agents.

From the experimental data it can be seen that: when the dissolving concentration of polyaluminum chloride PAC is 5%, the adding dosage of 1 ton of biogas slurry is 35L, the dissolving concentration of 20-ionic polyacrylamide PAM is 0.2%, and the adding dosage of 1 ton of biogas slurry is 55L, the two flocculants react with the biogas slurry together and are dehydrated by a spiral shell folding machine, the content TS of suspended matters in effluent is 1.01%, and the solid content TS of sludge is 20.3%.

Table 5 purpose of the experiment: in order to verify the influence of different adding amounts on the biogas slurry dehydration effect when polyaluminum chloride (PAC) and 20-ionic Polyacrylamide (PAM) are used as flocculants.

From the experimental data it can be seen that: the polyaluminum chloride PAC (polyaluminum chloride) has a dissolution concentration of 5%, when the dosage of 1 ton of biogas slurry is 30L, the dissolution concentration of 20-ionomeric Polyacrylamide (PAM) is 0.2%, and when the dosage of 1 ton of biogas slurry is 50L, the two flocculants react with the biogas slurry together and are dehydrated by a screw-stacking machine, the content TS of suspended matters in effluent is 1.01%, and the solid content TS of sludge is 20.3%.

Table 6 purpose of experiment: in order to verify the influence of different adding amounts on the biogas slurry dehydration effect when polyaluminum chloride PAC and 20-ionic-degree polyacrylamide PAM medicament are used as flocculating agents.

From the experimental data it can be seen that: the polyaluminum chloride PAC (polyaluminum chloride) has a dissolution concentration of 5%, when the dosage of a 1-ton biogas slurry is 25L, the dissolution concentration of 20-ionomeric Polyacrylamide (PAM) is 0.2%, and when the dosage of a 1-ton biogas slurry is 45L, the two flocculants react with the biogas slurry together and are dehydrated by a spiral shell stacking machine, the content TS of suspended matters in effluent is 1.18%, and the solid content TS of sludge is 20.0%.

The analysis of different dosage ratios in tables 4, 5 and 6 shows that: when the dosage of the polyaluminium chloride PAC per ton of biogas slurry is 30L and the dosage of the polyacrylamide PAM (20 ionicity) per ton of biogas slurry is 50L, the water and mud discharging effect is the best.

The analysis of the experimental data can be combined to determine that: selection of PAC and PAM agents and dosing ratio per ton of water, selection and dosing according to the data in table 1 are the best dosing regimens for the present invention.

The above description only discloses the preferred embodiments of the present invention, and the scope of the present invention should not be limited thereby, and all the simple equivalent changes and modifications made in the claims and the description of the present invention are within the scope of the present invention.

Claims (10)

1. The utility model provides a high-efficient stable process systems who gets rid of natural pond liquid suspended solid which characterized in that: the device comprises a biogas slurry pool, a high-efficiency spiral shell stacking dehydration device connected with the biogas slurry pool, a sewage pool connected with the spiral shell stacking dehydration device, a PAC dosing device and a PAM dosing device; the spiral shell stacking dehydration device comprises a stirring and mixing box and a spiral shell stacking dehydration machine which are connected with each other; the stirring and mixing box is respectively connected with a PAC dosing device, a PAM dosing device and a biogas slurry pool; the spiral shell overlapping dehydrator is provided with a water outlet and a sludge outlet, and the water outlet is connected with the sewage tank.

2. The process system for efficiently and stably removing the suspended substances in the biogas slurry, as claimed in claim 1, wherein: the PAC dosing device comprises a PAC dissolving box, a PAC liquid level sensor, a PAC dissolving stirrer, a PAC dosing pump and a dosing pipeline which is connected with the PAC dissolving box and is provided with a PAC dosing valve; the PAC water adding valve and the PAC liquid level sensor are automatically controlled in a linkage mode so as to realize automatic water supplement of the PAC medicine dissolving box; PAC adds the automatic antithetical couplet of medicine pump and PAC level sensor and controls, realizes carrying the PAC medicament automatically to the pipeline mixer that sets up on the natural pond liquid pipeline according to the liquid level of PAC dissolves the medical kit, makes it and natural pond liquid intensive mixing reaction.

3. The process system for efficiently and stably removing the suspended substances in the biogas slurry, as claimed in claim 1, wherein: the PAM dosing device comprises a PAM dissolving medicine box, a PAM liquid level sensor, a medicine feeding machine connected with the PAM dissolving medicine box, a dosing pipeline connected with the PAM dissolving medicine box and provided with a PAM dosing valve, and a PAM dosing pump connected with the PAM dissolving medicine box; the PAM dosing pump is automatically and jointly controlled by a liquid level meter in the PAM dissolving medicine box, and automatically conveys PAM medicines into the stirring and mixing box to react with sludge according to the liquid level condition of the PAM dissolving medicine box; PAM adds water valve and PAM level sensor automatic joint control in order to realize PAM dissolves the automatic water supply of medicine case.

4. The process system for efficiently and stably removing the suspended substances in the biogas slurry, as claimed in claim 1, wherein: the spiral-stacked dehydrator comprises a built-in variable-pitch spiral shaft, the variable-pitch spiral shaft comprises a concentration section and a dehydration section, and the spiral pitch from the concentration section to the dehydration section is gradually reduced.

5. The process system for efficiently and stably removing the suspended substances in the biogas slurry, as recited in claim 4, wherein: the screw pitch at the feed inlet end of the variable-pitch screw shaft is 195mm, and the screw pitch at the discharge outlet end is 110 mm.

6. The process system for efficiently and stably removing the suspended substances in the biogas slurry, as claimed in claim 1, wherein: the fermented natural pond liquid is collected to the natural pond liquid pond in, sets up dive mixer in the pond and carries out abundant mixing to natural pond liquid, makes the natural pond liquid concentration gradient in the pond within 0.5%.

7. The process system for efficiently and stably removing the suspended substances in the biogas slurry, according to claim 6, is characterized in that: the biogas slurry pool top is provided with a radar liquid level sensor and a biogas slurry pump which are automatically controlled to operate in a linkage manner, the submersible mixer is started and stopped along with the start and stop of the biogas slurry pump, the submersible mixer is started 5min before the biogas slurry pump is started, and the submersible mixer is stopped after the biogas slurry pump is stopped.

8. The process system for efficiently and stably removing biogas slurry suspension as claimed in claim 2, wherein the process system comprises: PAC medicament is regularly put into a PAC dissolving box, automatic water replenishing is realized through the automatic joint control design of an electric valve and a liquid level sensor on a water feeding pipeline, the PAC medicament is regularly dosed in batches, the dosage is 250 kg/batch, and the automatic water replenishing amount is 5m³Batch/batch.

9. The process system for efficiently and stably removing the biogas slurry suspension as claimed in claim 2, wherein the process system comprises: the rotor of the PAC dosing pump is made of stainless steel, and the stator of the PAC dosing pump is made of butadiene acrylonitrile rubber.

10. The process system for efficiently and stably removing the biogas slurry suspension as claimed in claim 3, wherein the process system comprises: the PAM medicament realizes stable medicament feeding through a PAM medicament feeder, the dosage is 2000g/h, and the automatic water replenishing amount is 1m³/h。

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