DE3007396A1 - Farmyard manure gas fermenter - with program controlled recirculation of floats and sinks layers - Google Patents

Abstract

A farmyard manure gas fermenter is a horizontal cylinder, made of steel, plastic, concrete, wood or combinations of them. One side wall has pipes for the gas extraction, for the supply of fresh manure and the pump connections for the sinks and floats layers. The opposite side wall has pipes for the outflow of the digested manure, for a recirculation and for the removal of extreme floats or sinks layers. This creates a plant which can be produced at a capital cost which equals the savings of fuel oil by the gas produced. It requires little maintenance.

Description

BIOGAS PLANT IN LYING CYLINDER DESIGN WITH SEPARATE GASOMETER

The invention relates to a biogas plant with a horizontal cylinder design for the anaerobic digestion of organic waste materials for the purpose of gas extraction and manure value improvement. By special control devices, in particular from the pump and safety and maintenance equipment is a trouble-free Decay guaranteed. In the case of smaller systems, the gas produced is of the invention included gasometer, with an inexpensive and functional construction is shown.

Due to the current energy situation it is necessary to find an alternative To tap energy sources. older and newer biogas plants at home and abroad show that it is possible with the various plant systems to produce biogas from organic To generate waste materials, in particular manure.

What these systems have in common is that they are even cheaper a cost of 1,500 to 2,000 DM per livestock unit (livestock unit with 500 kg). As a rule, this price only applies to inventory sizes of over 40 LU; i.e. with smaller stocks, the systems are even more expensive. With an average Energy requirement of 6,000 1 heating oil per farm per year is allowed For economic reasons, the system is not more expensive at current energy prices than 30,000 DM. With the assumed energy consumption, approx. 900 liters of heating oil are required needed in the coldest month of January.

30 LU can supply this amount of energy in the form of biogas. Consequently is the economic investment price for the system at 1,000 DM per LU Most existing systems also had the disadvantage that the necessary storage in the case of sinking layers (especially in the case of pigs slurry) and floating layers (especially for cattle slurry and solid manure) not, or if they can only be solved with great effort. Sink and floating layers that develop are the main reason for the failure of the systems. This is the case with the Schmidt-Eggersglüß system (Benediktbeuren) installed a telescopic stirring device, the works fully in its own way, but regular care with a high workload requires. In newer flow systems with a constant filling level Partly to find effective pump systems, but their automatic control is not yet resolved. Especially for systems with gas bells integrated in the case and the control excluded this is for a trouble-free and also efficient homogenizing and stirring operation is absolutely necessary.

Above all, foreign system manufacturers are trying this problem with different liquid manure levels, caused on the one hand by gas production and on the other hand to get a grip on different gas consumption.

Whether this is ultimately possible has been shown in practice in the longer term have not yet been proven, on the other hand, those systems require an extremely complicated one and thus expensive fermenter construction.

The invention is therefore based on the object of providing biogas plants in of any size, whereby the entire system price including the gas processing at DM 1,000 per LU for small stocks of 30 LU and larger stocks should move relatively even cheaper. In addition, the system should be easy to maintain his and the resulting sink and floating layers and the homogenization of Fresh and digested manure are carried out fully automatically. Still need to be factored in Malfunctions can be remedied without long-term interruption of the biogas operation. Additionally the gas should be available all year round with constant pressure.

The object is achieved in that the fermenter is a horizontal cylinder made of steel, plastic, concrete or wood or a combination. As a result, the zone of the sinking and floating layers is concentrated to a minimum.

The layers are removed by a central pump (Fig. 1 No. 6).

The pump is controlled in such a way that at certain time intervals (timer) alternately by slide control (Fig. 1 No. 9) the floating and sinking layers is stirred up. The decomposed substrate is transported through the return line (Fig. 1 No. 18) is injected in the period of time set by the timer, or longer if the pressure of the switching manometer (Fig. 1 No. 10) due to stratification shows a higher value than usual. Rises if there are any thick layers (especially with high solids content) the pumping time has to be specified maximum value, this is indicated to the supervisor by a display (bell, light). By means of the slide (Fig. 1 No. 13) these layers can then by opening and be removed while the pump is running. For larger systems is an automatic control is provided for this.

In the pump shaft (Fig. 1 No. 6) there is also an automatic pH sensor installed, which in turn in larger systems with the inoculation container (zig. 1 no. 12) or the fresh manure supply is coupled.

The fermentation is heated by means that are already on the market Systems, such as in Fig. 1 through an integrated wall heater (Fig. 1 No. 4) Plate heat exchangers or e.g. pipe coils.

The insulation is made with extruded polystyrene or with 2-shell Construction (larger containers) through cheaper insulation material.

The gas storage is not integrated in this system. That has the advantage that through the manhole provided at any time without long-term interruption a control can be made in the fermenter.

The resulting biogas itself is collected in a wet gasometer (Fig. 2). The water tank, which is provided with frost protection, consists of concrete rings, made of steel, plastic or wood. The gas dome floating in the water is also there to manufacture with appropriate materials. It is essential that the gas bell with a central tube (Fig. 2 No. 14) in a standpipe (Fig. 2 No. 2) out will. Because of possible snow loads and to avoid contamination of the guide device the gasometer is covered (Fig. 2 No. 6).

A shaft next to it accommodates the condensation separator (Fig. 2 No. 10) and the possibly necessary desulfurization tank (Fig. 2 No. 15). Any excess gas that has not been used is stored in the flaring device (Fig. 2 No. 12) burned.

For larger biogas plants with simultaneously high energy requirements or If you want a high fertilizer value for the decayed substrate, gas storage is recommended above the storage container (Fig. 1 No. 3).

Claims (5)

PATENT CLAIMS Biogas fermenter in horizontal cylinder construction, consisting from a container to be insulated (one-shell or two-shell) in various materials, characterized in that necessary openings for the manhole in the front wall (Fig. 1 No. 16), for gas extraction (Fig. 1 No. 17), for the fresh manure supply (Fig. 1 No. 7) and the pump tube openings for sinking (Fig. 1 No. 8) and floating layers (Fig. 1 No. 7), and necessary openings in the rear wall for the digested manure outlet (Fig. 1 No. 14), the backwash line (Fig. 1 No. 18) and the openings for removal extreme sinking and floating layers (Fig. 1 No. 13) are provided. 2. Automatically controlled hydraulic pumping device (Fig. 1 No. 6) in a compact design for simultaneous or subsequent installation, thereby characterized in that the agitation by time switch setting alternately by slide (Fig. 1 No. 9) with actuator actuation once at the top (for removing the floating layers, Fig. 1 No. 7) and once at the bottom (for removal of the sinking layers, Fig. 1 No. 8) he follows. If there is resistance, the specified duty cycle is determined by the installed Switching manometer (Fig. 1 No. 10) exceeded and can on a maximum period of time limited and indicated either audibly or visually and the need the sink and floating layer removal slide, which can be opened by hand (Fig. 1 No. 13) or have them open and close automatically. 3. Automatically controlled hydraulic pumping device according to claim 2, characterized in that the supply of fresh manure by hand or separate Pump actuation of the upper injection nozzle regardless of the specified switching times By automatic contact triggering, digested manure is mixed into the fresh manure flow. 4. Automatically controlled hydraulic pumping device according to claim 2 and 3 characterized in that an integrated automatic liquid manure pH sensor (Fig. 1 No. 11) a predetermined dose of the inoculated material (Fig. 1 No. 1 in the fore pit (Fig. 1 No. 1) releases or, depending on the circuit setting, the fresh manure slide opens for a limited time. 5. Gasometer with standpipe based on the water cup principle (Fig. 2), characterized in that the bell with a central guide tube (Fig. 2 No. 14) is guided in a stand guide tube (Fig. 2 No. 2) and the gas preparation takes place in an adjacent shaft.