CN110156298B

CN110156298B - Poultry manure treatment method

Info

Publication number: CN110156298B
Application number: CN201910502676.3A
Authority: CN
Inventors: 李华; 张伟; 杨军; 龚伟; 唐龙; 张文军; 雷云聪; 黄旗; 罗松
Original assignee: Mianyang Lianrui Intelligent Technology Co ltd; Southwest University of Science and Technology
Current assignee: Mianyang Lianrui Intelligent Technology Co ltd; Southwest University of Science and Technology
Priority date: 2019-06-11
Filing date: 2019-06-11
Publication date: 2021-12-17
Anticipated expiration: 2039-06-11
Also published as: CN110156298A

Abstract

The invention discloses a method for treating poultry manure, in particular to a method for dehydrating the poultry manure, aiming at solving the problems that the conventional dehydration treatment of the poultry manure usually needs a biological fermentation mode and has a long treatment period. The method comprises the following steps: adding a flocculating agent into the poultry manure to be treated, and uniformly stirring; then, squeezing and dehydrating the poultry manure treated by adding the flocculating agent, and putting the dehydrated poultry manure into an intermediate container; and applying an electric field to the intermediate container to change water molecules in the intermediate container into ion directional movement, so that the water in the poultry manure is separated from the solid matters. By adopting the invention, the high-efficiency dehydration of the poultry manure can be realized, the water content of the dehydrated manure can be reduced to below 45 percent, and the requirement of subsequent resource direct treatment of the manure is met. Meanwhile, the method has a short treatment period, can meet the continuous treatment requirement of the poultry manure, can be suitable for newly-built and existing poultry farms, and has strong adaptability and high application value.

Description

Poultry manure treatment method

Technical Field

The invention relates to the field of livestock and poultry waste treatment, in particular to the field of poultry manure treatment, and specifically relates to a poultry manure treatment method. More particularly, the invention relates to a method for dehydrating poultry manure, which can reduce the water content of the poultry manure to below 45 percent, thereby being beneficial to the subsequent manure treatment process and obtaining products such as organic feed, fertilizer and the like, having higher application value and having important improvement significance for the treatment of the poultry manure.

Background

The improvement is open, along with the increasing and increasing life of people, the livestock and poultry breeding industry in China is developed rapidly, and the market supply is greatly enriched. However, when intensive livestock farms are planned in the former site, most intensive livestock farms do not comprehensively consider the combination of agriculture and animal husbandry and the balance of breeding in the area, so that a large amount of livestock manure cannot be effectively processed in time. Because the excrement contains a large amount of water, various odors generated by the excrement can cause serious pollution to the air quality under the action of various microorganisms and enzymes; a large amount of nitrogen, phosphorus and additive residues in the excrement can permeate into the soil under the drive of moisture, damage is caused to the permeability and the structure of the soil, and the production value of the soil is reduced; meanwhile, after the excrement and urine are infiltrated by soil, the excrement and urine enter underground water for circulation, so that the water body is eutrophicated, thereby bringing about excessive propagation of algae and plankton and causing various ecological and environmental problems; in addition, various microbial germs and eggs bred in the accumulated excrement can cause the spread of various diseases. Therefore, the handling of feces is not very slow.

Therefore, the chinese patent CN200610096500.5 discloses a method for in-situ degradation of livestock and poultry excreta, which comprises culturing fully-decomposed livestock and poultry manure compost products to obtain inoculation liquid, and spraying and inoculating the inoculation liquid on a livestock and poultry house bedding layer to degrade the livestock and poultry excreta in situ. However, this method requires a specific treatment site and a certain treatment period, and when it is necessary to continuously treat the excrements of livestock and poultry, it is difficult to satisfy the corresponding treatment requirements.

Chinese patent CN201210498516.4 discloses a pollution abatement method for livestock and poultry farms. In the method, firstly, excrement and sewage are separated from fence flushing water and rainwater at the source; carrying out solid-liquid separation on the feces and the sludge generated in each treatment process; the separated liquid part is sent to a plug flow type anaerobic fermentation reactor or a liquid high-temperature aerobic fermentation reactor for liquid biological treatment, and then is subjected to aerobic fermentation and filtration to form a liquid organic fertilizer; and (3) sending the separated solid part to high-temperature aerobic fermentation equipment, and aging and deeply processing the solid part after fermentation to obtain the solid organic fertilizer. And (3) treating the odor by using a biological deodorization filter tower, then discharging, and sending the aged biological filter material replaced by the biological deodorization filter tower as a carbon source to a solid aerobic fermentation device for treatment. The water for flushing the fence is firstly treated by a grid impurity removal facility, is treated by an SBR sequencing batch bioreactor and is added with drugs for flocculation and precipitation, or is purified and discharged by a wetland, or is discharged after aerobic fermentation reaction and filtration, and the precipitated sludge and solid matters blocked by the grid are treated by a solid-liquid separation process. In the method, corresponding matched treatment facilities need to be established, the early investment is extremely large, and the method is not suitable for the existing livestock and poultry farms and has certain limitations.

Based on the characteristics of the livestock and poultry manure, the first process of treating the manure is to remove a large amount of water in the manure.

At present, a large number of poultry excrement dehydration devices are available on the market, and the most common poultry excrement dehydration device usually adopts a mechanical extrusion mode to realize dehydration. However, the simple mechanical pressing is not ideal for the compressing effect of the feces, and it can be known from the experimental data and the field operation that the existing equipment can remove at most 30% of water in the feces after compressing the feces (in this case, the water content in the feces is 65-70%). If the water content of the small-particle excrement is particularly high, the squeezing effect is worse, and only about 15% of water can be removed. Thus, mechanical compression, while removing some of the water from the poultry manure, is not effective enough to allow the manure to be reused (i.e., not subsequently disposed of).

Thus, chinese patent CN201010104194.1 discloses a composting method for biologically dehydrating livestock and poultry manure. In the method, under the condition of adding a biological fermentation bacterial agent, livestock manure is spread evenly and then added with fly maggots for fermentation, then the livestock manure and the biological fermentation bacterial agent are added in batches, the initial water content of the livestock manure compost is reduced by utilizing the synergistic action of microorganisms, and the effect of a compost fermentation strain is fully exerted. The method adopts biological fermentation, reduces water content, requires large treatment field, and has long production period.

Chinese patent CN201410141932.8 discloses a method and a system for rapidly reducing the moisture content in the feces and urine of livestock and poultry in the pretreatment process of organic fertilizer production, which comprises (1) establishing a treatment platform; (2) laying fermentation padding in the treatment platform; (3) adding livestock and poultry manure into the fermentation padding, adding a proper amount of fermentation strains, and uniformly mixing to form a material pile; (4) after the temperature of the material pile is increased to more than 50 ℃, adding the livestock and poultry manure, uniformly mixing, heating through fermentation to evaporate water, and repeating. The microbial fermentation technology is introduced into the pretreatment process of organic fertilizer production, and water is evaporated at high temperature generated by fermentation, so that the water content of the livestock and poultry manure is reduced. In the method, a biological fermentation mode is also adopted for dehydration, and the problems of large treatment site requirement and long production period exist.

Chinese patent CN201410318401.1 discloses a method and equipment for completing the fermentation and drying of excrement in one step, which utilizes chopped dry straws or fermented organic fertilizers or other dry organic materials as water absorbing raw materials, adds or does not add organic material decomposing agents, mixes the organic materials with the excrement, or directly sprays the organic materials and the excrement into livestock pens or toilet pits to absorb water in the excrement, adjusts the water content of the mixture to 30-50%, and puts the mixture into fermentation equipment for fermentation; when the fermentation temperature in the materials rises to above 55 ℃ and falls below 45 ℃, the fermentation is stopped, and after-ripening, the water content of the organic fertilizer reaches less than or equal to 15 percent; the fermentation equipment selects a heat-preservation and moisture-preservation net frame box group, a heat-preservation and moisture-preservation net frame box motorcade and a sunlight temperature-increasing fermentation chamber thereof; the fermentation environment is controlled to be above 16 ℃ and the humidity is below 60%, so that ventilation is facilitated; when the granular organic fertilizer is prepared, granulation is carried out firstly and then fermentation is carried out, and the fermentation and drying are completed in one step, so that the procedures of drying and smoke dust discharging are omitted. The method needs specific fermentation drying equipment, adopts a biological fermentation mode for dehydration, and has a long treatment period.

Therefore, a new method is urgently needed to solve the above problems.

Disclosure of Invention

The invention aims to: aiming at the problems that the conventional poultry manure is generally dehydrated by adopting a biological fermentation mode and the treatment period is long, the poultry manure treatment method is provided, in particular to the poultry manure dehydration method, so as to meet the requirement of rapid dehydration of the poultry manure. By adopting the invention, the high-efficiency dehydration of the poultry manure can be realized, the water content of the dehydrated manure can be reduced to below 45 percent, and the requirement of subsequent resource direct treatment of the manure is met. Meanwhile, the method has a short treatment period, can meet the continuous treatment requirement of the poultry manure, can be suitable for newly-built and existing poultry farms, and has strong adaptability and high application value.

In order to achieve the purpose, the invention adopts the following technical scheme:

a poultry manure treatment method comprises the following steps:

(1) adding a flocculating agent into the poultry manure to be treated, and uniformly stirring;

(2) squeezing and dehydrating the poultry manure treated by adding the flocculant in the step 1, and putting the dehydrated poultry manure into an intermediate container for later use;

(3) and (3) applying an electric field to the intermediate container containing the poultry manure in the step (2) to change water molecules in the poultry manure into ions to move directionally, so that water and solid in the poultry manure are separated, then performing solid-liquid separation, and collecting the poultry manure after the solid-liquid separation.

In the step 1, the initial water content of the poultry manure to be treated is 85-90%;

and if the water content of the poultry manure to be treated is higher than 90%, performing pretreatment by gravity filtration to obtain the poultry manure to be treated with the initial water content of 85-90%.

In the step 1, the addition amount of the flocculating agent is 2-5% of the mass of the poultry manure to be treated;

in the step 2, the pressure range of the extrusion dehydration is 0.8-1.2 MPa.

In the step 3, the electric field intensity range is 400-500V/m.

The flocculating agent is Al³⁺Of (3) or of Fe³⁺Of (3) or Al³⁺With Fe³⁺The polymer of (1).

In the step 1, the livestock and poultry manure to be treated is stirred, a flocculating agent is added in the stirring process, and the flocculating agent can be used for standby after the addition of the flocculating agent is finished.

And in the step 2, the livestock and poultry manure obtained in the step 1 is subjected to mechanical pressure dehydration, and the livestock and poultry manure is collected when the water content of the livestock and poultry manure after pressure dehydration is 50-55%.

In the step 3, the adopted solid-liquid separation comprises a spiral extrusion cavity, a first fixed end, a discharge hopper, a spiral auger, a second fixed end, a filter screen, an extrusion unit and an adjusting unit;

the spiral extrusion cavity is tubular with openings at two ends, the first fixed end is connected with the opening at one end of the spiral extrusion cavity, and the discharge hopper is arranged on the opening at the other end of the spiral extrusion cavity;

the spiral auger comprises a variable-pitch spiral section and a smooth section which is connected with the variable-pitch spiral section into a whole, and the variable-pitch spiral section is positioned between the first fixed end and the discharge hopper;

the second fixed end is connected with the spiral extrusion cavity through a connecting rod, and the spiral extrusion cavity can provide support for the second fixed end through the connecting rod; one end of the spiral auger, which is close to the variable-pitch spiral section, is movably connected with the first fixed end, the other end of the spiral auger is movably connected with the second fixed end, and the first fixed end and the second fixed end can respectively provide support for the spiral auger;

the spiral extrusion cavity is provided with a feed inlet and a water outlet respectively, the feed inlet is arranged at the upper end of the spiral extrusion cavity, a solid-liquid mixture can enter the spiral extrusion cavity through the feed inlet and is extruded by the spiral auger, the water outlet is arranged at the lower end of the spiral extrusion cavity, the filter screen is arranged between the spiral extrusion cavity and the variable-pitch spiral section, and water in the solid-liquid mixture can be discharged through the filter screen and the water outlet in sequence under the extrusion of the variable-pitch spiral section;

the extrusion unit comprises a stop block, a spring and a spring seat which are matched with the discharge hopper, the stop block, the spring and the spring seat are sequentially arranged on the smooth section, the stop block and the spring seat can respectively move relative to the smooth section, two ends of the spring are respectively connected with the stop block and the spring seat, the stop block is annular, and the stop block can be tightly attached to the discharge port under the pressure of the spring so as to close the spiral extrusion cavity;

the adjusting unit is connected with the second fixed end and the second fixed end can support the adjusting unit, the adjusting unit is connected with the spring seat and the adjusting unit can adjust the discharge pressure of the position of the spring seat to control the stop block.

The adjusting unit comprises an adjusting rod, a push rod and a push rod nut, the adjusting rod is movably connected with the second fixed end and can rotate relative to the second fixed end, the push rod nut is arranged on the adjusting rod, and the push rod nut is in threaded connection with the adjusting rod;

the push rod is at least two, the two ends of the push rod are respectively fixedly connected with the push rod nut and the spring seat, and the push rod nut can drive the spring seat to extrude the spring through the push rod so as to adjust the discharging pressure of the stop block.

The variable-pitch spiral section is designed in an equal diameter mode.

The push rod passes second stiff end and second stiff end can provide the support for the push rod.

Also comprises an adjusting hand wheel arranged on the adjusting rod.

The filter screen is annular.

The variable-pitch spiral section is designed by adopting a method comprising the following steps:

(1) the end of the variable-pitch spiral section close to the first fixed end is taken as an initial section, the end of the variable-pitch spiral section close to the discharge hopper is taken as a termination end, and the lead of the initial end is taken as p₀Let the lead of the terminating end be p_tThe total length of the spiral from the starting end to the terminating end is N spiral periodsDegree L₀Establishing a reference system, and assuming that the lead changes linearly along the axial direction, the parameter equation of the variable lead spiral is shown as the following formula (1):

in the formula (1), R is the radius of the spiral line, and ω t is the rotation angle of the spiral line;

wherein, in the specified length L₀Lead p of starting end when simple helical line of lead is generated internally₀End lead p_tSatisfies the following formula (2):

(2) if the outer radius of the spiral auger is R, the inner radius of the spiral auger is R, and the effective pressure P in the extrusion cavity is assumed to be in a linear distribution rule along the axis z, as shown in formula (3):

P＝k·z (3)；

axial force F borne by the spiral auger_aAnd the circumferential torque T are calculated by the following equation (4), respectively:

in the formula (4), S is a projection area of the helical curved surface along the axial direction z, and S is calculated by the following formula (5):

S＝π(R²-r²) (5)；

(3) and (3) determining whether the material of the variable-pitch spiral section and the design of the variable-pitch spiral section meet the requirements or not according to the design requirement of the extrusion force, the axial force Fa and the circumferential torque T obtained in the step (2).

And in the step 3, when the water content of the livestock and poultry manure after electroosmosis is 35-45%, collecting the livestock and poultry manure.

Crushing or granulating the excrement subjected to solid-liquid separation in the step 3, and using the crushed excrement as a feed additive, or breeding feed, or returning the crushed excrement to the field for application; or the excrement after solid-liquid separation is directly fermented after being crushed or particle-shaped to produce the organic fertilizer.

In view of the above problems, the present invention provides a method for treating poultry feces, and more particularly, to a method for dehydrating poultry feces to achieve rapid dehydration of poultry feces. In order to better remove water in excrement and improve the efficiency of mechanical extrusion, the applicant considers that a flocculating agent is added before excrement treatment, the excrement is flocculated before extrusion by adding the flocculating agent, and then the excrement is extruded, so that the dewatering amount of the excrement is effectively increased by the method. Through actual measurement, compared with the condition of direct extrusion without adding a flocculating agent, the water content of the excrement after the flocculating agent is added and the extrusion treatment is lower, the dehydration amount is increased by 8-10%, the water content of the treated excrement can be reduced to about 55%, but the secondary processing of the excrement (for example, the organic fertilizer preparation fermentation treatment usually requires the water content to be 35-45%) is still not ideal.

Therefore, the applicant further researches and discovers that the water content of the excrement can be further reduced by matching with the electric field dehydration in the step 3 of the invention after the flocculation treatment and the extrusion dehydration are carried out. The applicant finds that after the livestock manure is subjected to electroosmotic dehydration through a large number of experiments, the water content of the livestock manure which is not added with flocculation conditioning is reduced by 3-5 percent generally, while the water content of the livestock manure which is added with the flocculating agent conditioning can be reduced by 7-10 percent, and the water content of the manure which is subjected to electroosmotic dehydration is lower than 45 percent and can be directly reused. For example, the dehydrated feces are pulverized or granulated and used as feed additives, or as breeding feeds, or returned to the field for application; in addition, the dehydrated excrement can be directly fermented after being crushed or granulated to be used as a raw material for producing organic fertilizers.

Further, the applicant used existing screw extrusion solid-liquid separation equipment for separation. Then, in practice, the applicant found that in the existing screw extrusion equipment, the auger screw line is a conventional (equal pitch) screw line, and the extrusion force borne by the screw at different positions is different under the influence of the extrusion process, so that the extrusion efficiency of the extrusion equipment is lower, the energy consumption is higher, and the service life of the screw is shortened along with the extrusion efficiency. In addition, in the existing screw extrusion apparatus, the pressure adjustment of the blocking mechanism is realized by a gravity block, which also results in an increase in energy consumption to some extent.

For this reason, the applicant found, after careful study, that: when the existing screw extrusion equipment is adopted for separation, as the solid-liquid separation material contains more water, in the screw extrusion cavity for conveying and extruding the screw auger, along with the filtration of liquid, the distribution amount of solid substances is gradually concentrated from one end to the other end along the axial direction, and the pressure applied is correspondingly and gradually increased. Therefore, the spiral auger adopts the spiral surface with gradually changed lead, is more consistent with the actual extrusion working state, and is beneficial to improving the extrusion efficiency of the spiral auger for compressing materials; further, in order to simplify the structure, this application has carried out brand-new design to pressure regulation structure to improve extrusion efficiency, reduce the energy consumption.

In summary, unlike the conventional method of dehydrating poultry feces by biological fermentation, the present invention provides a novel method of dehydrating poultry feces, which organically combines flocculation treatment, extrusion dehydration, electric field separation and solid-liquid separation, so that the water content of the dehydrated feces can be reduced to below 45%, thereby facilitating the subsequent feces treatment. Meanwhile, the extrusion equipment is greatly improved, so that the extrusion equipment has higher extrusion efficiency and lower energy consumption. Based on the improvement of the treatment process, the treatment period of the invention is greatly reduced and can be less than one tenth of the treatment period of the existing biological fermentation, the extrusion energy consumption can be reduced by 15-30%, and the invention has considerable economic benefit. In addition, the product obtained by dehydration can be directly reused, and can be used as a feed additive and a breeding feed, or applied in a field returning way, or directly fermented to be used as a production raw material of an organic fertilizer.

Drawings

The invention will now be described by way of example and with reference to the accompanying drawings.

FIG. 1 shows an experimental apparatus for press dewatering.

Fig. 2 is a partially enlarged schematic view of fig. 1.

FIG. 3 is a graph of pressure dehydration of pig manure without and with the addition of a flocculant.

FIG. 4 is a graph showing the measurement of the addition of a flocculant.

FIG. 5 is a schematic structural diagram of the apparatus of the present invention.

FIG. 6 is a process flow diagram of the present invention.

Fig. 7 is a schematic structural diagram of the electric field unit in fig. 5.

FIG. 8 is a graph showing electroosmotic dehydration of livestock and poultry manure.

Fig. 9 is a reference frame diagram of a variable lead spiral line in embodiment 1.

Figure 10 is a graph of the variation of the helix along the lead z-axis.

FIG. 11 is a schematic view of the screw auger of example 1.

Fig. 12 is a schematic projection view of fig. 11.

FIG. 13 is a schematic structural diagram of a screw extrusion solid-liquid separation device.

The labels in the figure are: 1. tray, 2, guide post, 3, middle partition board, 4, guide sleeve, 5, support pillar, 6, bottom board, 7, beaker, 8, leakage cup, 9, pin shaft, 10, connecting rod, 11, piston, 12, filter cloth, 13, excrement, 14, insulating piston, 15, insulating cup body, 16, anode plate, 17, cathode plate, 18, funnel, 19, water absorption filler, 20, cathode joint, 21, anode joint, 50, the device comprises a pretreatment unit 51, a flocculating agent adding device 52, a filter pressing unit 53, an electric field unit 54, a molding unit 55, a water outlet device 61, a spiral extrusion cavity 62, a first fixed end 63, a discharge hopper 64, a spiral auger 65, a second fixed end 66, a filter screen 67, a feed inlet 68, a water outlet 69, a stop block 70, a spring 71, a spring seat 80, an adjusting rod 81, a push rod 82, a push rod nut 83 and an adjusting hand wheel.

Detailed Description

All of the features disclosed in this specification, or all of the steps in any method or process so disclosed, may be combined in any combination, except combinations of features and/or steps that are mutually exclusive.

Example 1

As shown in the figure, the process flow of the embodiment of the invention is as follows.

1) The mixture of the liquid dung and the water is naturally filtered (gravity or sedimentation separation), so that the water content of the liquid dung is about 85-90%.

2) Adding a flocculating agent into the liquid dung, fully stirring and mixing, destroying the binding force of water and organic matters in a non-biodegradation mode, and improving the dewatering and separating capacity of the liquid dung to be treated.

3) The excrement conditioned by the flocculating agent is subjected to pressing dehydration (namely, the pressing dehydration is carried out through a pressing filtration unit) through a mechanical force and a filter screen, and the water content of the obtained excrement is about 50-55%.

4) And applying an electric field to the excrement after extrusion dehydration, and leading water molecules to rapidly migrate under the charge adsorption of the electric field so as to further dehydrate. After treatment, the water content of the excrement is as low as 35-45%.

5) The solid phase substance separated by the step 4) becomes a product after modeling, and can be directly utilized or used as a raw material for deep processing, and the liquid product is subjected to harmless treatment such as deodorization to realize pollution-free discharge or used as fertilizer water for further processing and utilization.

(II) determination of experiment

(1) Experimental device

As shown in fig. 1 and 2, the device comprises a tray, a guide post, a middle partition plate, a guide sleeve, a support pillar, a bottom plate, a beaker, a leakage cup, a pin, a connecting rod, a piston, a tray and a guide post. Wherein, the bottom plate passes through the support column and constitutes main part support with the median septum, and the beaker setting is on the bottom plate. The guide sleeve is arranged on the middle clapboard and is matched with the guide pillar; the upper end of the guide post is connected with the tray, and the lower end of the guide post penetrates through the guide sleeve and can move relative to the guide sleeve. The leakage cup is arranged on the middle partition plate, the lower end of the leakage cup is matched with the beaker, and the upper end of the leakage cup is provided with a piston. The tray is connected with the piston through a connecting rod and a pin shaft in sequence; the tray can be linked with the piston through the connecting rod and the pin shaft in the downward moving process, so that the piston moves in the funnel. Meanwhile, the filter cloth is arranged at the upper end and the lower end of the leakage cup, and the excrement is positioned between the filter cloth.

When the device works, a heavy object is placed on the tray 1, and a guide post 2 and a connecting rod 10 are connected below the tray 1; the middle plate 3 and the bottom plate 6 are connected into a whole through a support column 5, the middle partition plate 3 and the guide column 2 form a moving pair through a guide sleeve 4, a connecting rod 10 is connected with a piston 11 through a pin shaft 9, the piston 11 can move in a leakage cup 8 placed on the middle partition plate 3, and a small through hole is formed in the middle of the bottom of the leakage cup 8 so that liquid in the leakage cup can flow out through the small hole. In the experiment, the upper and lower contact surfaces of the excrement 13 to be extruded are isolated by the filter cloth 12 and are placed in the leakage cup 8, after a proper amount of weight is placed on the tray 1, the piston 11 downwards extrudes the excrement 13, so that the moisture in the excrement 13 is forced to be separated, and the separated moisture is collected in the beaker 7 through the small hole at the bottom of the leakage cup.

(2) Measurement method

Weighing the experimental fecal sample, recording the weight as M, placing the sample in a leakage cup 8, adjusting the extrusion force applied to the sample by the weight placed on a tray, converting the extrusion force into pressure P (unit kPa), standing for a period of time (about 10min), fully dehydrating the sample, weighing the sample again, and recording the weight as M₂(ii) a Will weigh M₂The sample is put into an oven and dried at the temperature of 60 ℃, and the weight is measured for the third time after drying, and the weight is recorded as M₃。

If the meaning of water content is defined as the amount of water contained in a substance, the initial water content of a sample can be expressed as

The water content after press dewatering is expressed as

Subscript P indicates the current pressure level; in addition, for the sake of comparing the dewatering effect, the percentage of the total moisture in the material is expressed by the dewatering amount, and the dewatering amount under the pressure P is expressed as

(3) Determination of the experiment

Carrying out pressure dehydration experimental determination on a certain pig manure sample under the condition of not adding a flocculating agent, and showing a determination curve without adding the flocculating agent in a figure 3; fig. 4 shows a measurement curve of the flocculant addition, in which 200 mesh, 300 mesh, and 400 mesh show the number of holes in the filter cloth 12.

Comparing the two figures, it can be seen that the water content ρ of feces is not increased by the addition of the flocculant_1MPa61-63% and dewatering amount is eta_1MPa32-37%; and p after addition of the flocculant_1MPa48-53% of water and the dehydration amount is eta_1MPa55-63%, which shows that the use of the flocculating agent effectively improves the dehydration performance of the excrement.

(4) Processing apparatus

As shown in fig. 5, the device of the present invention comprises a pretreatment unit, a flocculant adding device connected with the pretreatment unit, a filter pressing unit, an electric field unit, a modeling unit and a water outlet device, wherein the filter pressing unit, the electric field unit and the modeling unit are connected in sequence; after fresh excrement and liquid dung in the excrement pool enter a pretreatment unit, adding a flocculating agent into the pretreatment unit through a flocculating agent adding device, and uniformly stirring under the driving of a stirring motor in the pretreatment unit; the poultry manure treated by adding the flocculating agent is sent into a filter pressing unit for squeezing and dewatering, the generated liquid is discharged through a water outlet device, and the dewatered poultry manure is sent into an electric field unit; the electric field unit applies an electric field to change water molecules in the water molecules into ions to move directionally, so that water in the poultry manure is separated from solid matters, the separated liquid flows out through the water outlet device, and the separated solid matters enter the modeling unit to support manure cakes for recycling treatment.

The electric field unit comprises a middle partition plate, an insulating piston, an insulating cup body, an anode plate, a cathode plate, a funnel, water absorption filler, a cathode joint, an anode joint, a stabilized voltage power supply and filter cloth, wherein the middle partition plate provides corresponding support; the anode plate is arranged below the insulating piston, the cathode plate is arranged below the insulating cup body, a funnel is arranged below the cathode plate, water absorbing materials are filled in the funnel, and the anode plate is respectively connected with a regulated power supply through an anode joint and the cathode plate through a cathode joint to form a current loop; an accommodating cavity for accommodating excrement is formed between the anode plate and the cathode plate, and filter cloth is respectively arranged at the upper end and the lower end of the accommodating cavity.

In the electric field unit, an insulating piston can move downwards in an insulating cup under the action of pressure so as to extrude a fecal sample, an anode plate is fixedly connected below the piston, a cathode plate is arranged below the insulating cup, a funnel is arranged below the cathode plate, and a water absorption filler is filled in a cavity of the funnel; the anode plate and the cathode plate are respectively connected with a voltage-stabilized power supply through an anode joint and a cathode joint. In the embodiment, the anode plate and the cathode plate are both formed by overlapping double-layer (or multi-layer) metal sheets, and water-absorbing filler is clamped between the layers; filter cloth is still arranged above and below the sample excrement.

(5) Determination of the experiment

When the weight is measured by experiments, the weight is M₂Placing the sample (dehydrated by pressure) in the electric field unit, switching on a voltage-stabilized power supply under the condition of keeping the pressure P, stabilizing the voltage at V volts, performing electroosmotic dehydration on the sample excrement, standing for a period of time (about 10min), weighing the sample excrement, and recording the weight as M₄(ii) a The dried mass is still marked as M₃The water content of the sample after electroosmosis is

The amount of dehydration is

FIG. 8 is a set of curves determined by electroosmotic dehydration of pig manure using the present invention. Dividing the sample feces into A, B groups, wherein the group A is not added with flocculant, the group B is added with flocculant, and after extrusion dehydration is carried out under the pressure of 1MPa, the water content of the group A, B respectively reaches rho_1MPa61.3% and ρ_1MPa51.6 percent; then, A, B groups were divided into six portions and subjected to electro-osmotic dehydration at 5/10/15/20/25 and 30V, respectively, to obtain A, B curve.

As can be seen from FIG. 8, the water content of group A was reduced from 61.3% to 57.8% by electroosmosis, the percentage point was reduced by 3.5%, and the water content of group B was reduced from 51.6% to 44.2% by 7.4%; therefore, the electroosmosis can dehydrate the livestock and poultry manure, and the livestock and poultry manure conditioned by the flocculating agent has better electroosmosis dehydration performance; and after the experimental voltage exceeds 10V, the effect of electroosmosis on the dehydration effect of the excrement is not greatly influenced. Further, solid-liquid separation equipment of the subsequent part (IV) is adopted to treat the excrement under the action of the electric field, and the water content of the group B is further reduced to 40.3 percent.

Further, this example uses a completely new apparatus to perform solid-liquid separation.

The spiral extrusion solid-liquid separation equipment comprises a spiral extrusion cavity, a first fixed end, a discharge hopper, a spiral auger, a second fixed end, a filter screen, an extrusion unit and an adjusting unit. Wherein, the spiral extrusion cavity is the tubulose of both ends open-ended, and first stiff end links to each other with the one end opening of spiral extrusion cavity, goes out the hopper setting on the other end opening of spiral extrusion cavity. The spiral auger comprises a variable-pitch spiral section and a smooth section which is connected with the variable-pitch spiral section into a whole, and the variable-pitch spiral section is positioned between the first fixed end and the discharge hopper. In this embodiment, the variable pitch helical section is designed by using a constant diameter variable pitch design, and the design of the variable pitch helical section is as shown below. Simultaneously, the second stiff end passes through the connecting rod and links to each other with spiral extrusion cavity, and spiral extrusion cavity passes through the connecting rod and provides the support for the second stiff end.

One end of the spiral auger close to the variable-pitch spiral section is movably connected with the first fixed end, the other end of the spiral auger is movably connected with the second fixed end, in the structure, the first fixed end and the second fixed end are used for supporting the spiral auger respectively, and the spiral auger can rotate relative to the spiral extrusion cavity under the driving of the driving mechanism, so that the extrusion of materials is realized.

In addition, a feed inlet and a water outlet are respectively arranged on the spiral extrusion cavity, the feed inlet is arranged at the upper end of the spiral extrusion cavity, the water outlet is arranged at the lower end of the spiral extrusion cavity, and the filter screen is arranged between the spiral extrusion cavity and the variable-pitch spiral section. In this embodiment, there are two water outlets.

Simultaneously, the extrusion unit includes and goes out hopper matched with dog, spring holder, and dog, spring holder set gradually on smooth section and dog, spring holder can move smooth section relatively respectively, and the both ends of spring link to each other with dog, spring holder respectively, and the dog is the annular and the dog can closely laminate in order to realize closing to spiral extrusion cavity with the discharge gate under the pressure of spring.

The adjusting unit comprises an adjusting rod, an adjusting hand wheel connected with the adjusting rod, a push rod and a push rod nut, the adjusting rod is movably connected with the second fixed end, the adjusting rod can rotate relative to the second fixed end, the push rod nut is arranged on the adjusting rod, and the push rod nut is in threaded connection with the adjusting rod. The push rods are at least two, and the two ends of each push rod are fixedly connected with the push rod nuts and the spring seats respectively. In this structure, the push rod nut passes through the push rod and drives spring holder extrusion spring to adjust the ejection of compact pressure of dog. Simultaneously, the push rod passes the second stiff end, and the second stiff end can provide the support for the push rod.

And (II) as the solid-liquid separation material contains more water, in a spiral extrusion cavity for conveying and extruding the spiral packing auger, along with the filtration of liquid, the distribution quantity of solid substances is gradually concentrated from left to right along the axial direction of the figure, and the pressure borne by the spiral packing auger is gradually increased from right, so that the spiral packing auger adopts a spiral surface with gradually changed lead, is more consistent with the working state of actual extrusion, and is favorable for improving the extrusion efficiency of the spiral packing auger for compressing the material.

(V) mathematical description of variable-lead spiral line of spiral auger

Let the lead of the left start of the helix be p₀Right side termination lead of p_tFrom the start end to the end, N helical periods pass, and the total length is L₀If a reference system is established as shown in fig. 9 and the lead is assumed to vary linearly in the axial direction, the parametric equation of the variable-lead spiral is shown in the following formula (1):

in formula (1), R is the radius of the helix, and ω t is the angle of rotation of the helix.

At the same time, at a predetermined length L₀The lead from the start end to the stop end is as followsFormula (2):

if the outer and inner radii of the screw auger are R and R, respectively, one embodiment of the screw auger is shown in fig. 11 and 12.

Since the material is gradually extruded from the inlet to the outlet, the pressure gradually increases along the z-axis, so it is assumed that the pressure in the extrusion chamber varies linearly along the axis.

The working surface and the non-working surface of the helical blade should have a pressure difference; considering that the material is a liquid-solid mixture, the mixture is sparse at an inlet and has small pressure difference, and at an outlet end, the material is in a semi-dry state due to the separation of moisture, and the action of the extrusion contact force between a non-working surface and the material is tiny relative to a working surface in the rotary extrusion process, so that the distribution of pressure is approximately considered, and the influence of negative pressure is ignored.

In the spiral extrusion cavity, the radial dimension is smaller relative to the axial dimension, and the pressure change along the radial direction is ignored;

the solid-liquid material only needs to be pushed at the inlet, and the contact pressure acting on the helical blade is very small relative to the extrusion contact force of the outlet end, so that the pressure at the inlet is assumed to be 0.

The four points assume the pressure distribution characteristics in the extrusion cavity, the error influence caused by approximation and neglect is considered, and the corresponding safety coefficient is set for correction; the safety factor is selected by considering the influence caused by different water contents of the inlet materials, and can be selected from 1.1-1.3 according to empirical estimation.

If the effective pressure P in the extrusion chamber is assumed to be linearly distributed along the axis z, as shown in equation (3):

P＝k·z (3)。

then deducing, the axial force Fa and the circumferential torque T borne by the spiral auger are respectively as follows:

in the formula (4), S ═ pi (R)²-r²) And is the projected area of the helical curved surface along the axial direction z.

In the formula, the physical quantity units are respectively: k-MPa/mm; p is a radical of₀、p_t、L₀—mm；F_a—N；T—N.mm。

(2) Mathematical description of a pressure regulating device

Setting the working pressure at the discharge port end as P ═ kL and the rigidity of the spring as K, the initial installation compression amount of the spring is

If the lead of the thread pair of the push rod nut and the adjusting hand wheel is S, the pressure of the spring is increased or reduced when the adjusting hand wheel rotates for one circle:

ΔF＝SK (6)；

therefore, the extrusion working pressure is adjusted by rotating the adjusting hand wheel.

(VI) practical application

(1) The working process of the extrusion device is as follows: the solid-liquid mixed material enters the spiral extrusion cavity from the feeding hole and is conveyed along the movement direction of the spiral auger, the water in the material is filtered by the filter screen and then is filtered out from the water outlet, and the solid substance is conveyed to the discharging hopper; because the stop block is pressed by the spring, the solid materials are accumulated in the area close to the discharge hopper and are extruded by the spiral auger, and the extrusion force acts on the left side of the stop block; the extrusion force is gradually increased along with the increase of the solid material, until the extrusion pressure is increased enough to overcome the acting force applied to the stop block by the spring, the spring is further compressed, the discharge hopper and the stop block are changed from a contact state to a separation state, a gap is generated, and the solid material is extruded out of the gap.

The extrusion force is adjusted as follows: the spring is supported on the spring seat by the end, the spring seat is fixedly connected on a push rod nut by a push rod with connecting threads at two ends, and the push rod nut is connected with an adjusting rod provided with an adjusting hand wheel through a thread pair; when the adjusting hand wheel is rotated forwards or backwards, the push rod nut moves leftwards or rightwards under the action of the thread pair, so that the spring seat moves leftwards or rightwards by pushing the push rod, and the adjustment of the compression amount of the spring is realized. In the structure, the pressure of the extrusion side of the stop block can be adjusted by adjusting the magnitude of the spring force borne by the stop block.

In the previous experiment, the extrusion device of the embodiment is independently used for dehydration experiment, and the experimental result is as follows: the power of the motor is 3kW, the lead is 160mm, the rising value is 80mm, 5 periods of the helical blades are provided, and when the pressure of the outlet of the helical compression is set to be 0.8MPa, the excrement 7.6160 multiplied by 10 with the water content of 80 percent can be treated within one hour³kg is reduced to 3.0464X 10³kg, the water content of the dehydrate is reduced to 50%.

(2) Performance variation after using a variable lead screw auger

In order to compare the performances of the variable-lead spiral line and the non-variable-lead spiral line, under the condition that other parameter conditions are not changed, when the fixed-lead spiral auger A and the variable-lead spiral auger B with N periods are respectively adopted to realize the extrusion with the same pressure P, the stress condition can be discussed, the lead of the auger A is set to be constant P, and the lead of the auger B is gradually changed from P to qp; q is a lead change parameter, the theoretical value range is (0,1), and the value of practical application is suggested to be 0.4-0.6.

For the packing auger A, when P is constant, the packing auger A can bear axial force F when reaching the extrusion effect of pressure P by the (4) type packing auger A_aAnd the load torque T is respectively

As the lead of auger B gradually changes, the length of auger B changes from L ═ Np to L' as shown in formula (2) compared with auger A, and

the packing augers B and A realize the same extrusion pressure P, so that the distribution parameter k of the pressure in the spiral extrusion cavity is changed into

The formula (8) and the formula (9) are substituted into the formula (4), so that the axial force Fa 'and the load torque T' borne by the packing auger B are obtained

A number table in which q takes different reference values is established according to the equations (8) and (10), as shown in Table 1 below.

TABLE 1

Lead variation parameter q	q＝0.4	q＝0.5	q＝0.6	q＝0.7
					Auger spiral length L'	0.7L	0.75L	0.8L	0.85L
Axial force Fa'	1.14Fa	1.11Fa	1.08Fa	1.06Fa
					Load torque T'	0.7T	0.75T	0.8T	0.85T

From the above, when the same extrusion effect is obtained, the variable-lead screw auger has the following advantages compared with the non-variable-lead screw auger:

(1) the axial size of the variable-lead spiral auger is shortened by 15-30%, namely the structure is more compact, and the material cost and the occupied space are saved;

(2) the load torque of the variable-lead spiral auger is reduced by 15-30%, namely under the condition of achieving the same extrusion effect, the energy consumption can be reduced by 15-30% by adopting the variable-lead spiral auger structure.

The invention is not limited to the foregoing embodiments. The invention extends to any novel feature or any novel combination of features disclosed in this specification and any novel method or process steps or any novel combination of features disclosed.

Claims

1. A poultry manure treatment method is characterized by comprising the following steps:

if the water content of the poultry manure to be treated is higher than 90%, performing pretreatment by gravity filtration to obtain the poultry manure to be treated with the initial water content of 85-90%;

in the step 2, the pressure range of the extrusion dehydration is 0.8-1.2 Mpa;

in the step 2, the livestock manure in the step 1 is subjected to mechanical pressure dehydration, and the livestock manure is collected when the water content of the livestock manure after pressure dehydration is 50-55%;

(3) applying an electric field to the intermediate container containing the poultry manure in the step 2 to change water molecules in the intermediate container into ions to move directionally, so that water and solid in the poultry manure are separated, then performing solid-liquid separation, and collecting the poultry manure after the solid-liquid separation;

the adjusting unit is connected with the second fixed end and can provide support for the adjusting unit, the adjusting unit is connected with the spring seat and can adjust the position of the spring seat to control the discharging pressure of the stop block;

the variable-pitch spiral section is designed in an equal diameter mode;

(1) the end of the variable-pitch spiral section close to the first fixed end is taken as an initial section, the end of the variable-pitch spiral section close to the discharge hopper is taken as a termination end, and the lead of the initial end is taken as p₀Let the lead of the terminating end be p_tFrom the start end to the end, N helical periods pass, and the total length is L₀Establishing a reference system, and assuming that the lead changes linearly along the axial direction, the parameter equation of the variable lead spiral is shown as the following formula (1):

P＝k·z (3)；

S＝π(R²-r²) (5)；

(3) determining whether the material of the variable-pitch spiral section and the design of the variable-pitch spiral section meet the requirements or not according to the design requirement of the extrusion force, the axial force Fa and the circumferential torque T obtained in the step 2;

2. The method for treating poultry manure according to claim 1, wherein in step 1, the amount of the flocculant added is 2 to 5% by mass of the poultry manure to be treated, based on the poultry manure to be treated.

3. The poultry manure treatment process of claim 1, wherein the flocculant is Al³⁺Of (3) or of Fe³⁺Of (3) or Al³⁺With Fe³⁺The polymer of (1).

4. The method for treating poultry manure according to claim 1, wherein in step 3, the electric field intensity is in the range of 400 to 500V/m.

5. The poultry manure treatment method according to claim 1, wherein the adjusting unit comprises an adjusting rod, a push rod and a push rod nut, the adjusting rod is movably connected with the second fixed end and can rotate relative to the second fixed end, the push rod nut is arranged on the adjusting rod, and the push rod nut is in threaded connection with the adjusting rod;

6. The method of claim 5, further comprising an adjustment handwheel disposed on the adjustment lever.

7. The method for treating poultry excrements according to any one of claims 1 to 6, wherein in step 3, the excrements after solid-liquid separation are pulverized or granulated and used as feed additives, or as breeding feeds, or returned to fields for application; or the excrement after solid-liquid separation is directly fermented after being crushed or particle-shaped to produce the organic fertilizer.