JPH0243711B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for processing livestock, especially cow dung, into liquid fertilizer.

Conventionally, a pit is installed underground to process cow manure and the waste is aerated and turned into liquid fertilizer. However, each cow produces 50 kg of cow dung per day. In Hokkaido, it is common to raise large numbers of cows, and if you raise 100 cows today, five tons of manure will be produced each day. The manure treatment tank is selected to be between 200 and 1000 tons. Therefore, the excreta treatment tank is large-scale, and in Hokkaido, where land is relatively easy to use, above-ground excrement treatment systems using above-ground tanks are often used due to the price of the excrement treatment tank.

FIG. 1 is a longitudinal cross-sectional view schematically showing a conventional above-ground excrement treatment tank. 1 is a slurry tank installed on the ground, the bottom of which is made of concrete, and the surrounding wall made of a cylindrical steel plate, in which cow excrement is stored. A sub-pit 2 with a much smaller capacity than the slurry tank 1 is provided underground, and raw water from cow excrement is poured into the sub-pit 2. The sub-pit 2 is equipped with a vertical shaft slurry pump 3, and the manure liquid sucked into the vertical shaft slurry pump 3 passes from the sub-pit 2 through a discharge pipe 6, and is sent to the slurry tank 1 via a liquid supply pipe 8 and a liquid fertilizer via a switching valve 7. Divided into extraction pipe 9. The slurry is then dropped onto the surface of the excreta from the liquid supply port 12 via the switching valve 11 at the top of the slurry tank 1. A liquid feed pipe 14 that directly connects with the switching valve 11 opens laterally at the bottom of the slurry tank 1.

The bottom of the slurry tank 1 and the sub pit 2 are connected by a liquid feed pipe 15, and at the end of the liquid feed pipe 15 that opens into the sub pit 2 there is a gate valve 16 that can be operated from the ground.
is provided.

A floating surface aeration device 17 is arranged above the surface of the liquid to be treated in the slurry tank 1 .

In liquid fertilizer processing using such an above-ground slurry tank, aeration is performed using the surface aeration device 17, while raw water of manure is added to the sub pit 2, and when the liquid fertilizer has progressed and removal is possible, a vertical shaft slurry pump is used. 3 to pump up the liquid in the sub pit 2 and transfer it to the slurry lorry 18 from the liquid fertilizer take-out pipe 9 via the switching valve 7. The liquid near the bottom of the slurry tank 1 moves by gravity to the sub-pit 2 through a liquid feed pipe 15 and an open gate valve 16, and is transferred from the sub-pit 2 to a slurry lorry 18.

The liquid is sent by the vertical shaft slurry pump 3 via the switching valve 7 from the sub pit 2 through the liquid feeding pipe 8, and then to the liquid supply port 12 via the switching valve 11, or through the liquid feeding pipe 14.
to the bottom of slurry tank 1.

In any case, excrement will enter the slurry tank 1. Therefore, the action of the gate valve 16 is that when the gate valve 16 is closed, the liquid level in the slurry tank 1 rises, and when the gate valve 16 is opened, the liquid flows from the slurry tank 1 to the sub pit 2. There, the vertical shaft slurry pump 3 is operated, and the liquid circulates through the slurry tank 1 and the sub-pit 2. The reason for doing this is that the slurry tank 1 is the surface aeration device 17.
This is because only surface aeration is carried out, and unless the liquid is taken out from the tank bottom and returned to the aerated liquid surface, the liquid at the tank bottom will not be treated at all.

This method aerates and stirs the liquid surface using a surface aeration device 17, etc., but the stirring power is weak, the stirring radius is small, and the stirring power does not reach the bottom of the tank. An operation to compensate for this is necessary. However, the force of the liquid spouted from the end of the liquid sending pipe 14 only partially stirs the liquid around the spout, and the stirring and aeration of the liquid other than the surface of the tank are extremely weak. Moreover, during the severe winter, the surface aeration device 17 cannot produce sufficient stirring aeration, and the outside air (minimum -20
(°C to -30°C), the temperature is not suitable for fermentation of aerobic bacteria, and in the end, surface aeration does not play any role in biochemical treatment, and therefore fermentation heat is generated separately. The liquid level inside the slurry tank 1 is then frozen by the outside air. Therefore, when liquid fertilizer should be applied to pastures in the first spring, the manure used as fertilizer is not matured and cannot be applied due to freezing, which hinders the operation of above-ground manure treatment systems.

The present invention is suitable for the above-mentioned above-ground manure treatment system that is often used in cold regions, and can obtain fully matured manure when liquid manure fertilizer is applied to pastures in the first spring, and can also be used as a slurry. The object of the present invention is to obtain an above-ground liquid fertilizer processing device for cow manure that is suitable for an above-ground manure processing system in which the tank does not freeze.

The present invention includes an above-ground slurry tank, a sub-pit that communicates with the above-ground slurry tank through a gate valve via a gravity flow pipe, and a liquid-feeding pump in the sub-pit. In an above-ground manure treatment system, which is equipped with liquid piping and liquid manure extraction piping to the slurry lorry, an underwater aeration device at the bottom of the above-ground slurry tank, and a defoaming device above the above-ground slurry tank, multiple underwater This is an above-ground excrement processing apparatus, which includes an aeration device, and each of the aeration devices has a center of jet flow directed in the same manner in the circumferential direction of the slurry tank.

The underwater aeration system of the present invention is preferably equipped with an aeration system equipped with a non-obstructive submersible pump.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 is a longitudinal sectional view. The above-ground slurry tank 1 and the underground sub-pit 2 have a liquid feed pipe 1 that opens into the sub-pit 2 via a gate valve 16.
5 to allow natural flow, and the cow excrement in the sub-pit 2 is sucked in by the vertical shaft slurry pump 3 and discharged into the discharge pipe 6. The vertical shaft slurry pump 3 can also be a submersible pump. The cow manure discharged from the discharge pipe 6 is sent to the slurry tank 1 through a liquid supply pipe 8, and is branched from the discharge pipe 6 and connected to a liquid manure take-out pipe 9 via a stop valve 19. An aeration device 20 is provided at the bottom of the above-ground slurry tank 1.

FIG. 3 is a longitudinal sectional view of the aeration device 20. The submersible motor pump, which is installed at the bottom of the tank and is generally indicated by 21, has a motor 22 at the top and an intermediate casing 24 fixed to the lower bracket 23 of the motor 22 below.The intermediate casing 24 has a shaft sealing device (not shown). A semi-open impeller 26 is fixed to the end of the main shaft 25 through which the shaft sealing device is inserted, and the impeller 26 is housed in a pump casing 27 fixed to the intermediate casing 24. A suction port 29 is provided in the pump casing 27 at a space from the open front surface of the pump casing 27 . Legs 31 are integrally provided in the pump casing 27 to support the submersible motor pump 21 and to form a flow path in front of the suction port 29. The space 28 and its outer periphery serve as a vortex chamber, and the vortex chamber is connected to the discharge port 32. A pump constructed in this manner is called a vortex pump.

The ejector, generally indicated by 33, is a nozzle 34 that spouts liquid supplied from the submersible motor pump 21.
, the combined pump casing 27 and air chamber 3
A diffuser 36 is secured to the air chamber 5 and extends straight into the air chamber 35 for restoring the pressure of the velocity energy of the liquid jetted from the nozzle 34.

A diff user is clamped and fixed at the tip of the ejector 33 by means of a fixture 37 erected at the bottom of the slurry tank 1. Further, an air introduction pipe 38 through which a gas such as the atmosphere is introduced opens into the air chamber 35, and the pipe extends upward and opens into the atmosphere. A muffler 41 is provided.

When the motor 22 is started, the main shaft 25 and therefore the impeller 26 rotate, and the planar shape projected on the page of FIG. 3 inside the impeller 26 is as follows. A vortex A centered on the extension of the main shaft 25 is generated, and the liquid sucked in from the suction port 29 is directed from the vortex chamber toward the discharge port 32 while swirling in a spiral shape.

The liquid flowing out from the discharge port 32 is injected into the air chamber 35 by the nozzle 34 and comes into contact with the inner wall 36' of the tube in the straight section of the diffuser 36.
As a result, the air is sucked through the air introduction pipe 38 and comes into contact with the surface of the injected liquid, gradually narrowing the air passage 40, tangentially bringing the inner wall and liquid together, and then the velocity energy is restored to pressure, resulting in a diff user. It flows out from 36. At this time, as a result of the action of the vortex pump, the liquid flowing out from the discharge port 32 crosses or intersects the extension of the main shaft 25; The water flow is given a twist as it rotates around the center. Therefore, as a result of twisting the water flow through the nozzle 34, air chamber 35, and diffuser 36 to create a gentle swirling flow, the liquid injected from the nozzle 34 swirls around the inner wall 36' of the straight pipe of the diffuser 36. Since the contact area with the air increases, and since the straight pipe part of the diff user 36 also turns, the same effect as if the straight pipe part was made longer is obtained, and the amount of air inhaled is increased. The amount of air flowing into the pipe increases, and the inhaled air moves toward the center of the pipe, making the path for the bubbles to become finer longer. It is something that can be done.

According to this aeration device 20, the swirling flow of the pump is maintained through the nozzle to the air chamber and the diffuser, so that the amount of air intake is significantly increased. Since it is a vortex pump, the solids can also be circulated in the slurry tank 1, and the solids are ejected from the aeration device along with the liquid, so that the aeration effectively acts on the liquid content and composition to be treated.

A defoaming machine 42 is arranged at the top of the slurry tank 1.

FIG. 4 is a longitudinal sectional view showing details of the defoamer 42. Beam 51 spread between the upper edges of slurry tank 1
A bearing protection case 50 in the form of an airtight container with a base plate 43 fixed to the top by bolts is attached to the bolt nut 4.
It is attached by 5. A bearing bracket 46 is fixed to the base plate 43 so as to be inside a bearing protective case 50, and an electric motor 47 is fixed by bolts and nuts 48.

The bearing 49 mounted on the bearing bracket 46 is fixed so as not to move in the axial direction by a bearing cover 52 fixed to the bearing bracket 46, and the stepped portion 53 prevents the main shaft 53 from moving in the axial direction by the bearing 49.
a and 53b are brought into contact with the inner ring of the bearing 49 and supported. One end of the main shaft 53 is fitted into one shaft coupling piece 55a of a coupling 55 via a key 54, and the other shaft coupling piece 55b of the coupling 55 is fitted with a key 54.
It is inserted into the shaft end of the electric motor 47 via. The coupling 55 connects the shaft coupling pieces 55a and 55b by coupling bolts 57 (details not described) arranged on the circumference and opened in the axial direction so as to transmit rotational force.

For example, a semi-open impeller 58 suitable for removing bubbles is inserted into the lower end of the main shaft 53 via a key 59, and a shaft top bolt 61 is inserted through the bolt hole at the center of the boss of the impeller 58 and screwed into the main shaft 53. The boss of the impeller 58 is pressed against the stage 62 and fixed.

The action of the defoamer 42 is that the foam rises to below the impeller 58, but the impeller 58 liquefies the foam and blows it away. Therefore, bubbles are extinguished in a certain range, and bubbles remain from the liquid level of the slurry tank 1 to the impeller 58, but the bubbles do not rise any further.

In addition, in a defoaming device consisting of a motor and an impeller, the motor is provided with an opening that communicates with the outside air and an opening that communicates with the air chamber of the aeration device. When using a defoaming machine (Utility Application No. 1979-079472), which is characterized by forming an air passage that passes inside or outside and cooling the motor by the suction action of an aeration device, the motor of the defoaming machine can be cooled. Since it has the effect of heating the incoming air using heat generation and cooling the motor, the air introduced by the aeration device is heated, which is convenient for promoting fermentation. When using this defoamer, the air introduction pipe 38 of the aeration device 20 is connected to the defoamer 42.

FIG. 5 is a plan view of the slurry tank, showing the arrangement of the aeration device 20 and defoamer 42.
In this embodiment, two aeration devices 20 and two defoaming machines 42 are provided, but three or more sets may be installed. Generally, as the capacity of the slurry tank 1 increases, the number of aeration devices 20 and defoaming machines 42 increases will increase.

The aeration device 20 is arranged symmetrically close to the peripheral wall of the slurry tank 1 so that jet centers 63 from the ejector 33 face in opposite directions and are parallel to each other.
That is, each aeration device 20, 20 is connected to the slurry tank 1.
The jet center 63 is oriented in the same rotation direction in the circumferential direction. The defoamer 42 is connected to the jet center 63 of the ejector 33 and the jet center 63 of the slurry tank 1.
It is placed between the surrounding walls closer to. And defoaming machine 4
A beam 51 supporting the aeration device 20 is disposed so as to pass above the aeration device 20. By arranging the beams 51 in this way, the aeration device 20, electrical wiring to the defoamer 42, and support for the air introduction pipe 38 can be performed by one beam, and the aeration device 20 can be lowered to the bottom of the tank. It is convenient because it serves as a support member for the cargo handling equipment that is pulled up from the bottom.

In the ground-type excrement processing apparatus of the present invention configured as described above, the vertical shaft pump 3 is operated to supply the liquid containing cow excrement raw water in the sub pit 2 to the discharge pipe 6 and the liquid supply pipe 8.
The slurry is sent to the slurry tank 1 through. The raw water in the sub-pit 2 is transferred to the slurry tank 1 unless the slurry tank 1 becomes full. The vertical shaft pump 3 is operated intermittently when the winter slurry tank 1 is filled with water, and the gate valve 16 is also opened and closed intermittently in accordance with the operation of the vertical shaft pump 3. As a result, the sub-pit 2 is agitated by the liquid exiting the gate valve 16, promoting mixing of aerobic bacteria. Since the raw water ratio of cow manure in the sub-pit 2 is high, organic matter is supplied from the sub-pit 2 to the slurry tank 1.

An aerator 20 is operated in the slurry tank 1. In this operation method, at the beginning of the liquid fertilizer fermentation process, aerobic seed bacteria are first produced, and the operation is close to continuous operation for the purpose of further rapid multiplication. Such continuous operation in the initial stage is also useful for reducing the viscosity of highly viscous raw water (manure) by aeration, and for forming convection currents in the slurry tank through effective stirring.

FIG. 6 is a diagram showing the decrease in the viscosity of the raw manure water in the slurry tank 1, in which the horizontal axis shows the number of operating days of the aeration device and the vertical axis shows the viscosity cp of the manure in the slurry tank 1. As shown in viscosity curve 64, the amount of manure that was about 1200 cp in the first six days becomes about 50 cp.
There is a rapid decline to a certain point, and there are few changes after that. Therefore, in the early stages of liquid fertilizer production, the viscosity is lowered by continuous operation to sufficiently mix the aerated air into the manure and increase the opportunities for aerobic bacteria to come into contact with the air.

If this operation continues, fermentation will progress and the temperature of the liquid will rise. At the same time, the viscosity is significantly reduced, and the stirring flow effectively causes convection within the slurry tank 1, so that the oxygen supplied by the ejector 33 spreads to every corner of the slurry tank 1.
When the liquid temperature rises to a certain extent, aerobic bacteria become significantly activated, and even when switching to intermittent operation, the liquid temperature rises close to that of continuous operation.
(Because the amount of air supplied by the underwater aeration device is large) This is because in the above-mentioned underwater aeration device, the air supplied by the ejector 33 is already in continuous operation and becomes fine bubbles, which flow from the bottom of the tank to every corner of the slurry tank 1. This is because the mixture is stirred until it dissolves into the manure, resulting in a long retention period suitable for the respiration of aerobic bacteria.

When the aerator 20 is operated, the gas-liquid mixture flows as shown by C in FIG. Therefore, the cow manure in the slurry tank 1 is completely supplied with air necessary for aerobic fermentation from the bottom of the tank to the liquid surface. On the other hand, fresh organic matter from cow manure is supplied from the end of the liquid feed pipe 8 onto the liquid surface of the slurry tank 1, gradually moves downward, and is sent from the bottom of the tank to the sub pit 2 via the liquid feed pipe 15 for circulation. When aeration is performed, bubbles are generated on the liquid surface. If left unattended, this foam will overflow over the upper edge of the slurry tank 1. Then, the defoamer 42 is operated. The defoamer 42 may be operated intermittently as long as the foam does not rise.

On the other hand, the air and water ejected from the ejector 33 of the aeration device 20 spreads laterally from the jet center 63 of the ejector 33, as indicated by the symbol D in the plan view of FIG. These flows C and D are rotated by a slow vortex with a high speed centered on the center of the slurry tank 1. Figures 2 and 5 are combined with arrows C and D.
As you can see, the cow manure in slurry tank 1 is thoroughly stirred and is supplied with air.
Therefore, the organic matter decomposition process by aerobic bacteria is carried out over the entire cow excrement in the slurry tank 1, and there is little bias.

As is already well known, bubbles appear above the liquid surface rather than in the manure. Therefore, a lot of bubbles are generated right above the front surface of the ejector of the aeration device, but the bubbles only swell up in that area, and instead spread on the liquid surface to form a foam layer. Therefore, as already mentioned, a defoamer 42 is arranged as shown in FIG. 5 in order to maintain the foam layer optimally through experiments. When the defoamer 42 is operated, the defoaming effect extends within the dashed double-dot line E in the figure. The bubbles that come into contact with the impeller 58 are liquefied, and are blown away by the centrifugal force from the impeller 58, further liquefying other bubbles as they fly. Therefore, the aeration device 20
When the defoaming device 42 is operated while the defoaming device 42 is operated and bubbles are continuously generated, a concave foam surface centered on the defoaming device 42 is created. Therefore, since the defoamer 42 is disposed between the peripheral wall of the slurry tank 1 and the jet center 63 of the ejector 33, the foam does not overflow beyond the peripheral edge of the slurry tank 1. Since the bubbles below are not extinguished by the impeller 58 due to the nature of defoaming by the impeller 58, the surface of the manure liquid in the slurry tank 1 is reliably covered with bubbles and kept warm.

FIG. 7 is a diagram showing experimental data using the above-ground excrement processing apparatus of the present invention. The horizontal axis shows the number of days, and the vertical axis shows the temperature and aeration amount.

Reference numeral 65 is a line indicating the temperature of the manure in the slurry tank 1, and this temperature was the same at any location at the depth of the liquid. That is, it is indirectly shown that the stirring is sufficiently performed. Code 66 is the aeration amount m ³ /
hr, symbol 67 is a line indicating the daily temperature of the outside air.

When the slurry tank 1 is filled with cow manure, the aeration device 20 is continuously operated. As already mentioned, when the viscosity of the internal manure decreases and aeration becomes effective, the aeration device 20 is operated intermittently. When the aeration device 20 is operated intermittently with 30 minutes of operation and 30 minutes of rest, the temperature of the liquid to be treated rises rapidly at first, and as soon as it reaches a turning point about 5 days after starting intermittent aeration, the temperature increase rate decreases. . The temperature reaches 40 degrees Celsius in about 16 days after starting intermittent aeration. Even after 16 days after starting intermittent aeration, the temperature of the liquid to be treated continues to rise. Although the outside air temperature 67 fluctuates during this time, the temperature of the manure in the slurry tank 1 is hardly affected by daily temperature changes.
It is known that the degree of spoilage of manure can be determined by changes in pH, and initially slurry tank 1
Internal manure is PH7.4, PH8.2 on the 11th day, PH on the 22nd day.
It was 8.4. Therefore, the temperature of the manure in the slurry tank mentioned above rises to about 40 degrees Celsius, and after that it rises only slightly, which is lower than the temperature rise of 50 degrees Celsius in similar processing in warm regions, but it is thought to be due to heat radiation due to the outside temperature. It will be done. However, the pH has changed to 8.4, indicating that it is ripe. Note that the amount of aeration was reduced from about the 14th day onwards in accordance with the decline in the bacterial growth rate.

When ripening progresses in this manner, the gate valve 16 is opened to operate the vertical shaft slurry pump 3, and the stop valve 19 is opened to transfer the liquefied cow manure to the slurry lorry 18 from the liquid manure take-out pipe 9 and spread it.

As described above, the above-ground excrement treatment apparatus of the present invention has a plurality of submerged aeration devices at the bottom of the slurry tank, and each of the aeration devices has a jet center directed in the same rotation direction with respect to the circumferential direction of the slurry tank. The above-ground excrement treatment apparatus is characterized by the following: Aeration is applied to all the liquid to be treated in the slurry tank, and all the liquid to be treated is uniformly and well stirred. Fermentation heat is generated uniformly in the liquid to be treated, and foam on the liquid surface can be kept to the maximum extent possible by a defoamer without overflowing to the outside of the tank, resulting in good heat retention. In the embodiment, a defoamer is placed between the peripheral wall of the slurry tank near the aeration device and the center of the aeration jet, which is convenient for preventing foam from overflowing and leaving foam on top of the liquid. In this embodiment, since the aeration device is equipped with a vortex pump, the aeration air often mixes into the liquid to be treated, so as to further emphasize the above-mentioned effects.

In this way, the aeration device and defoamer installed at the bottom of the slurry tank promote ripening regardless of the low temperature of the outside air, making it possible to obtain highly effective manure liquid fertilizer regardless of the season. Uniform aeration can also play a role in preventing pollution, such as preventing bad odors.

Note that the aeration device described above is a vortex pump aeration device equipped with a submersible motor pump, but any device may be used as long as at least the ejector is submerged in water and aeration is performed at the bottom of the slurry tank.

[Brief explanation of the drawing]

Fig. 1 is a vertical cross-sectional view of a conventional above-ground excrement processing device, Fig. 2 and the following are drawings related to embodiments of the present invention, where Fig. 2 is a longitudinal cross-sectional view, and Fig. 3 is a longitudinal cross-sectional view of an aeration device. , FIG. 4 is a longitudinal cross-sectional view of the defoamer, FIG. 5 is a plan view of the slurry tank, FIG. 6 is a diagram showing the viscosity of the material to be treated in the slurry tank, and FIG. 7 is the slurry tank of the present invention. FIG. 3 is a diagram showing daily changes in internal temperature. 1...Slurry tank, 2...Sub pit, 3
...Vertical shaft slurry pump, 6...Discharge pipe, 7...
Switching valve, 8...Liquid feeding pipe, 9...Liquid fertilizer extraction pipe, 11
...Switching valve, 12...Liquid supply port, 14, 15...Liquid feeding pipe, 16...Gate valve, 17...Surface aeration device, 18...Slurry lorry, 19...Stop valve, 20...Aeration Device, 21... Submersible motor pump, 22... Motor, 23... Lower bracket,
24... Intermediate casing, 25... Main shaft, 26...
...Impeller, 27...Pump casing, 28...
Space, 29... Suction port, 31... Leg, 32... Discharge port, 33... Ejector, 34... Nozzle, 3
5... Air chamber, 36... Defuser, 36'...
...pipe wall, 37 ... fitting, 38 ... air introduction pipe,
39... Gate valve, 40... Passage, 41... Silencer, 42... Defoamer, 43... Base plate, 44... Bolt, 45... Bolt nut, 46... Bearing bracket, 47... Electric motor , 48... Bolt nut, 49... Bearing, 50... Bearing protection case, 5
1... Beam, 52... Bearing cover, 53... Main shaft,
53a, 53b...Stepped portion, 54...Key, 55...
...Coupling, 55a, 55b...shaft coupling piece,
56...Key, 57...Couple spring bolt, 5
8... Impeller, 59... Key, 61... Shaft top bolt, 62... Stage, 63... Jet center, 64... Viscosity curve, 65... Temperature line, 66... Aeration amount, 67
……Outside temperature.

Claims (1)

[Claims] 1. An above-ground slurry tank, a sub-pit that communicates with the above-ground slurry tank via a gate valve via a gravity flow pipe, and a liquid sending pump in the sub-pit, and liquid sending piping from the above-ground slurry tank to the above-ground slurry tank. In an above-ground manure treatment system that is equipped with liquid fertilizer extraction piping to the slurry lorry, an underwater aeration system at the bottom of the above-ground slurry tank, and an antifoaming device on the top of the above-ground slurry tank, multiple submersible aeration systems are used. An above-ground excreta processing apparatus, characterized in that each of the aeration devices has a center of jet flow directed in the same rotational direction with respect to the circumferential direction of the slurry tank.