DE8304514U1 - Device for generating biogas from liquid manure - Google Patents

Description

Device for generating

of biogas from liquid manure

When raw materials are becoming increasingly scarce, renewable ones are being used Sources of energy and raw materials are of increasing importance. Processes that can use such sources. v: ichtige Contributions to environmental protection. They have a special meaning for developing countries, since with them foreign exchange for Raw material and energy imports are saved and these processes have a positive influence on regional development.

These processes include generation and use. Biogas is of particular importance and it is fclger.-de Advantages a:

Energy generation from locally available, organic waste and supply especially to rural households;

Production of high quality organic fertilizer;

Improvement of the sanitary conditions, since biogas plants represent decentralized waste treatment systems .;

Protection of the forest and bush through the use of the thermal energy of the biogas;

Promotion of manual and technical skills through construction and operation of the biogas plants.

Pi; The central unit for generating bi 'gas is the digester, in which organic material is broken down under anaerobic conditions - preferably organic waste such as human or animal excrement and plant residues. This creates biogas, a mixture of approx. HO % CH ^ and 40 % CO ₉ .

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The invention relates to a device for generating biogas from liquid manure, in particular one that has a flexible, includes cylindrical and gas-tight container.

For the optimal digestion process, a fermentation temperature of 32-35 C must be set and for the duration de? Maintain fermentation process, with rapid temperature fluctuations of the Sustrates are to be avoided.

In temperate climates, heat energy must therefore partly be obtained from the gas to maintain the temperature in ien fermentation tanks are returned, which reduces the effective yield of the process, if not waste heat from others Sources are available.

In tropical and subtropical areas there is a heating problem of minor importance and can sometimes even go unnoticed. Goes in the short season of lower ambient temperatures If the gas production is reduced in unheated systems, then this loss is economically justifiable expensive heating systems.

Agriculture and livestock farming are the main activities in these geographical areas, and there are diverse biogas plants different design of the digester known. These work more or less satisfactorily. The rotten one Mass is a high-quality fertilizer and is urgently needed there to increase agricultural yields.

A horizontally arranged flexible cylinder made of a plastic similar to PVC is used to a certain extent as a digester Experienced. This flexible container, commonly known as a "bag", lies in a flat concrete bowl on the ground and isl exposed to the weather. At most, this 3ag is covered with a plastic tarpaulin. This execution is simple and ir. Countries with a lower level of technology practiced this. fair and inexpensive to build yourself.

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A major disadvantage is the sensitivity of this bag

proven against mechanical stresses from the outside,

which can come from rodents, birds and termites. Furthermore, with these simplest arrangements

insufficient influence on the benevolent leadership of the

Temperature can be taken.

The invention has for its object to provide such a device that the fermentation tank made of plastic before mechanical Protects external loads and enables the temperature in the interior of the container to be influenced.

This object is achieved according to the invention by the device
solved according to the main claim in conjunction with claim 2.

The invention described below t-draws on the application of the fermentation tank ^ .us flexible plastic materials in
a transport container of internationally agreed dimensions.,
whereby in addition to the mechanical protection of the bag given in this way, temperature control through the use of solar energy, for example, is provided? will beat.

Containers such as those in;.,

^ 3 ο ■> * »QoVn fTd Vii ^ f m'nffocaf" ^ CTTIr ^ ll * - *. - ^ C 1 1 Γ »V" i Q 11 "P fS OT · ^ TT ¹ U Ro IJ V, H T- ".

Be transported by rail. With these units is the core, ·; piece of a biogas plant, the empty digester, a certain
Mobility is given, and larger systems can be made up of several
the same units can be put together, ie one which '=! Standardization that reduces costs is hereby given. y

According to the task, through a biological process from the i. latent energy potential in the biomass combustible gas to i.? generate, one can speak of an energy conversion unit here.

The device to be described is also more suitable
Place between farms that are common for the size of the
entire biogas plant have required livestock,
to be built and can also serve as a community facility.
In addition, decentralized waste treatment is also available here at | Think about settlements. 1

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For the purpose proposed here, a transport container is sufficient, the is no longer used in luxury traffic and ΐ can be acquired cheaply in the so-called second-hand trade

ι is.

The containers under consideration here have internal dimensions of length χ width χ height of 6 58 χ 2 438 x 2 591 mm a content of 32 rc and can have a mass of maximum 24 load 400 kg. The largest container of this design has the Dimensions 12,000 χ 2,333 x 2,591 mm and a volume of 66 m. The maximum load is 35,000 kg.

The invention is explained in more detail below using an exemplary embodiment with reference to the drawings:

Show it

1 shows the view of the entire device with cutouts to show details;

Fig. 2 is a cross-section along section line A-B

through this device
and

Fig. 3 shows the detail of the Warmwasseraufgäbe shown

through the section C-D in Fig. I.

In the container (2), which is prepared to hold the plastic bag (1) and is to be described in more detail, the material to be fermented j e.g. manure from pigs and / or cattle as well as suitably shredded vegetable residues enter the digester on the "V" side ( 3) _s runs through this according to the plug-flow process with a dwell time of approx. 15 days and leaves it rotten on the "W" side.

The liquid manure (3 a) fills the digestion chamber to about 65 to 75 % ₃ and above this is the collecting space (3 b) for the biogas, which is discharged at the top through the line (4) to the consumer directly or into an intermediate storage .

The bag (1) can easily be attached to the smooth inner walls and rest against the bottom of the container. With a dark paint on the outside, the container surface absorbs

the radiation of the sun and gives off the heat to the interior by conduction in the adjacent surfaces, the bag and by convection in the air space around it.

To protect the plastic skin against local overheating on the Contact points of the wall parts heated by the sun and for keeping the temperature in the interior are according to the invention suggested v; ie shown in particular in Fig. 2:

The bag (1) rests on a support frame, consisting of longitudinal spars (h a) over approximately the length of the container and at intervals of transverse spars (4 b) with fittings (^ c) so that on the floor between the longitudinal spars channels along the container, limited ö TCh the spars (4 a), container floor and bag are formed. Hardwood, for example oak or teak, is intended as the material here. To prevent the bar from falling to the side, heat-insulating panels (5), also made of hardwood, are arranged along the wall, which act as rubbing strips. The interior of the container is closed off on both sides of the door behind the doors through the walls (6) so that a waterproof tub is formed. This tub is filled with water up to line "z", which is heated to heat the bag and thus represents a heat store. To limit the water tightness and to prevent overfilling, the overflow (7) is inserted into a bulkhead. The interior of the container is provided with a suitable protective coating against corrosion in the area of the water filling.

To limit the heat losses in this container space there is a "z" on the outside of the longitudinal walls up to above the water line Thermal insulation layer (8) attached. For VJ poor insulation of the floor is one of the cavities between the strip fur.damenten (9) earthfill (10) closing at the edge is sufficient in such a way that that there is no air flow under the floor.

To heat the water, a solar collector of the simplest design is attached to the wall of the container facing the sun suggested. It consists of a coil (11) that forms the heat exchanger and is attached to the black

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Wall rests on and is connected to this. For the production a forced circulation of the water is a circulation pump (12) (only external energy supply) provided, which draws the water from the digester outlet side "W" through the pipe (11 a), through the heat exchanger (11) promotes and warms up on the inlet side "V" to heat the fresh manure through the Brings tube (11 b) back into the water space. The switching of the pump can depend on the output temperature of the Water in the collector with comparison of the temperature of the water in the container. There are tried and tested devices for this with circuits that are not part of the invention.

Instead of solar energy to heat the WasGer, the Waste heat from an internal combustion engine operated with biogas from the system can be used as it is done in principle, e.g. in block-type heating power stations. This possibility. is given without further effort if the biogas is emitted by means of a combustion engine-generator combination and the The resulting waste heat is fed into the biogas production. Or is a thermal bath used in the Bioga? to the Hot water preparation is burned, e.g. controlled in such a way that the heater is activated when the fermentation temperature falls below the most favorable value (Instantaneous water heater) is switched on.

In Fig. 3 the end of the tube (11 b) of the solar collector (11) with its bores (11 c) to the water outlet is vcr the Channels between the longitudinal spars (4 a) are shown.

In addition to the solar collector shown on the vertical wall of the container, one or more of them can be placed on the Roof side be arranged, inclined according to the geographical latitude of the installation site as shown in Fig., 2 in dashed lines Lines is shown.

Of the. The process sequence can be seen in Fig. 1:

The manure, a daily amount for example, is put into the container (13.) promoted, be it by manual operation or pump and runs through the pipe (ΐΌ, which is through a not shown

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Slide: it can be locked into the digester, displaces the crowd that longitutional strives through the septic tank. The same amount of digested digestion leaves the container through the outlet (15) and overflows its weir (16). The weir height determines the level "y" of the liquid manure in the digester. The hydrostatic pressure, measured by the height difference between the upper edge of the outlet pipe (15) and the weir (16), determines the gas pressure in the gas collecting container. This collecting container is not shown and should simply be the same plastic container as the digester in a container of the same type, but the surface of which should have a color that reflects light heat radiation.

The containers are stackable so that with the gas storage coni-jiner placed on the digester container, the smallest possible space requirement for the installation of the system is available.

With this arrangement of the weir height and thus level control e ir. Digester, a simple self-regulation of the manure quantity ir. Given the putrefaction. Further modifications of the method, which are not described here in more detail, certainly bring about improvements the gas yield, but additional mechanical devices such as stirring mechanisms complicate the digester and strongly influence the investment costs for the use of the described system in developing countries of of decisive importance are and limit the possibility of self-assembly, self-installation and maintenance the operator.

The areas of application of the systems described according to the invention with containers 6,058 and 12,000 mm in length as follows:

Container with a length of 6 O58 mm:

Filling amount of manure he 15 m corresponds to 70 % filling of the rig. At a Verv; The time of 15 days for the biological material is 1,000 kg of fresh manure. For pigs ν -η 75 kg weight per ¹ . ^ dose amount · ί at <'ne ::>

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Average value of 3 kg manure per pig and day from around 300 animals, i.e. a small pig farm. The gas yield of about 0.2 Nm ³ biogas per animal and day is therefore 60 m- ⁵ . These 300 pigs with a weight of 75 kg per animal correspond to around 45 cows, i.e. 45 LU (cattle unit with a weight of 500 kg).

The container with a length of 12 m is suitable for a farm with 500 pigs, i.e. for a quantity of liquid manure of 1.5 m ⁵ / day. The filling of the digester for 15 days of residence time of the biological mass is 22,500 kg ^ liquid manure and the gas yield is around 100 standard cubic meters of biogas per day.

Assuming a daily gas requirement of 0.2 standard cubic meters per person for cooking purposes, then this is the specified amount of gas sufficient for the supply of 500 people.

Claims (2)

-1- claims: 1. A device for generating biogas from liquid manure, which comprises a flexible, cylindrical and gas-tight container for receiving the biological mass, characterized in that the flexible cylindrical container ( ¹ ) is adapted to a conventional transport container (2) and stored in this. 2. Apparatus according to claim 1, characterized in that in the lower region of the container interior in the free space between the wall of the container (1) and the container side walls. and a water bath is built up to the water line ("z") to heat the biological mass in the fermentation tank. 3 · Device according to claims 1 and 2, characterized • Fishing through one on the outside wall of the container assigned solar collector, heat exchanger • Heating up of the water beard. • M. device according to claim 1 to 3, characterized! through a thermal insulation layer on the outer wall of the Containers.