Large horizontal device for continuous methane fermentation and method thereof

Abstract

A large-type horizontal device and a method for continuous methane fermentation belong to dry biogas fermentation technology. The whole distribution of a fermentation compartment uses a U-shape plane layout which is a snap-back type and uses a material propeller. The material propeller has two axes and two blades and is constantly occluded with counter rotation. The irreversible propulsion of materials can be realized through counter rotation of two occluded blades. The propeller is set at the bottom of the main partition of the fermentation compartment. Since the impeller blades adopt a long side design in rotation axis directions, a large amount materials can be propelled. The propel ability of propeller can be changed through changing of rotation speed. Counter rotation of two occluded blades can realize material propeller without material reverting. The inlet and outlet entrances of the reactor in the disclosure are near to the ground and can be operated conveniently to, therefore, save energy. The homogeneous output of materials and entire plug-flow can be realized at the same time without material mixing in the whole process. This makes fermentation more complete.

Claims

1. (canceled)

2. (canceled)

3. A large horizontal device for continuous methane fermentation, the device comprises: a hydrolysis feed compartment, a hydrolysis heating feeder, a hydrolysis feed heater, a hydrolysis feeder, a hydrolysis feed inoculation and homogenizing compartment, a hydrolysis inoculator, a hydrolysis fermentation compartment, a hydrolysis feed distributor, a hydrolysis materials propeller, a hydrolysis material ejection balancer, a hydrolysis ejector, a hydrolysis gas stirring distributor, a hydrolysis gas circulation draught fan; a methane fermentation feeder, a methane fermentation and inoculation homogenizing compartment, a methane fermentation material inoculator, a methane fermentation compartment, a methane fermentation feed distributor, a methane fermentation material propeller, a methane fermentation ejection balancer, a methane fermentation ejection compartment, a methane fermentation feed heater, a methane fermentation stirring gas distributor, a methane fermentation gas circulation draught fan, a vertical main partition, a parapet, a horizontal main partition, wherein: the hydrolysis feed compartment and the hydrolysis feed heater are connected through hydrolysis heating feeder, the hydrolysis heating feeder is in the hydrolysis feed compartment and runs through hydrolysis feed heater, the hydrolysis feed heater connects the hydrolysis feed inoculation homogenizing compartment through the hydrolysis feeder, the hydrolysis feed inoculation homogenizing compartment connects an inlet of hydrolysis fermentation compartment through the hydrolysis feed distributor, an outlet of hydrolysis fermentation compartment connects hydrolysis ejection compartment through a hydrolysis material ejection balancer, the hydrolysis feed inoculation homogenizing compartment and the hydrolysis ejection compartment are connected through the hydrolysis inoculator, the hydrolysis ejection compartment connects the methane fermentation feed heater through the hydrolysis ejector, the methane fermentation feed heater connects the methane fermentation feed inoculation homogenizing compartment through the methane fermentation feeder, the methane fermentation feed inoculation homogenizing compartment connects an inlet of methane fermentation compartment through the methane fermentation feed distributor, an outlet of methane fermentation compartment connects the methane fermentation ejection compartment through the methane fermentation ejection balancer, the methane fermentation feed inoculation homogenizing compartment and the methane fermentation ejection compartment are connected by the methane fermentation material inoculator; the methane fermentation compartment and the hydrolysis fermentation compartment generally are reinforced concrete, the vertical main partition is set in the middle of the hydrolysis fermentation compartment for propelling materials in order, the vertical partition divides the hydrolysis fermentation compartment into two parts and sets route of materials in hydrolysis fermentation compartment to be U-shape, and each part are divided into several grids by alternate horizontal main partitions and parapets, hydrolysis fermentation material propeller is set under every horizontal main partition in each grid, in order to make the materials move forward up and down, besides, hydrolysis gas distributor for gas stirring is installed at the bottom of the hydrolysis fermentation compartment, the top part of hydrolysis fermentation compartment is an assembly zone of hydrolysis gas, and the gas inside is ejected through the hydrolysis gas distributor for pas stirring after compression the by hydrolysis gas circulation draught fan; the methane fermentation compartment is the same as the hydrolysis fermentation compartment with two parts divided by a vertical main partition and a U-shaped material flowing route, each part are divided into several grids by alternate horizontal main partitions and parapets, a methane fermentation material propeller is set under the horizontal main partition such as to force the materials moving forward up and down in methane fermentation compartment, and a methane fermentation stirring gas distributor is set at the bottom of methane fermentation compartment, the top part of the methane fermentation compartment is an assembly zone of methane, and the gas inside is ejected through a methane fermentation gas distributor after compression by the methane fermentation gas circulation draught fan; and the material propellers are placed under the reverse vertical main partitions at the end of both the methane fermentation compartment and the hydrolysis fermentation compartment to collect materials, and wherein every propeller includes two long axis impellers, two propeller driving axis, and a propeller shell, each long axis impeller is a cylinder overall with impellers in an axis direction such as to apply a long side design in driving axis directions, and a vertical cross-section is like a dumbbell with arcs at both ends and in the middle, each long axis impeller has a propeller driving axis, and the axis of two long impellers is parallel and synchronous rotate in reverse direction, one is clockwise while the other one is anticlockwise and two impeller blades are constantly occluded and seal in the whole rotation process, outside each long axis impeller there is a propeller shell, and an internal surface is half arc, making the impeller be tangent with the corresponding half arc internal wall during the rotation, there are blocks set outside the propeller shells such as to divide each side out of the propeller into two parts, and the viscous half-solid materials are transported from one side to the other side through rotation of the long axis impeller.

4. The device of claim 3, wherein the fermenting materials in the hydrolysis feed compartment is put in proportion and then driven by the hydrolysis heating feeder, the materials move into hydrolysis feed heater and being heated, and then the hydrolysis feed inoculation homogenizing compartment is driven by hydrolysis feeder, with the combined effect of the hydrolysis inoculator, hydrolysis feed distributor, and hydrolysis materials propeller, the materials are inoculated and homogenized and propelled in the hydrolysis fermentation compartment, the materials are stirred by the compressed gas flow from hydrolysis gas stirring distributor in hydrolysis fermentation compartment, in the meantime, with the help of the hydrolysis material propellers set in fermentation compartment, the materials move forward slowly along the flow direction, the whole hydrolysis fermentation lasts for 5 to 6 days, finally, the last hydrolysis material propeller in hydrolysis fermentation compartment drive most of the materials into the methane fermentation feed heater through the hydrolysis material ejection balancer and the hydrolysis ejector, a small amount of the materials to the hydrolysis feed inoculation homogenizing compartment through the hydrolysis inoculator in order to finish the inoculation, those materials in the methane fermentation feed heater is being heated, and during the heating process, the hydrolysis acidize bacteria are eliminated or inhibited at high temperature (60 to 65° C.); and the materials after hydrolysis, acidulation, and heating enter the methane fermentation feed inoculation homogenizing compartment through the methane fermentation feeder, with the combined effect of methane fermentation material inoculator, the methane fermentation feed distributor, and the methane fermentation material propeller, the materials are re-inoculated and homogenized, then are propelled in the methane fermentation compartment, with the help of the methane fermentation material propellers set in fermentation compartment, the materials move forward slowly during the whole fermentation which lasts for 20 days, at last, the last methane fermentation material propeller in the methane fermentation compartment propels material to methane fermentation ejection compartment through the methane fermentation ejection balancer, a few materials enter the methane fermentation feed inoculation homogenizing compartment through the methane fermentation material inoculator to finish inoculation of methane bacteria, the other materials of outlet finish the whole fermentation.

5. The device of claim 4, wherein: during the continuous fermentation process, after passing the hydrolysis feed heater, the materials are heated up to 33±2° C., and the hydrolysis fermentation staying time is 5 to 6 days; and after going through the methane fermentation feed heater, the materials are heated up to 60 to 65° C. for the fermentation lasts for 20 days.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0035] FIG. 1: the schematic diagram of large-type continuous methane fermentation device, as illustrated in FIG. 1, the two lines which are overstriking are material propellers;

[0036] FIG. 2: the 5-5 cross-section diagram of FIG. 1;

[0037] FIG. 3: planar diagram of methane fermentation compartment;

[0038] FIG. 4: the 1-1 cross-section diagram of fermentation compartment in FIG. 3;

[0039] FIG. 5: the 2-2 cross-section diagram of fermentation compartment in FIG. 3;

[0040] FIG. 6: planar diagram of hydrolysis compartment;

[0041] FIG. 7: 3-3 cross-section diagram of hydrolysis compartment in FIG. 6;

[0042] FIG. 8: 4-4 cross-section diagram of hydrolysis compartment in FIG. 6;

[0043] FIG. 9: enlarged diagram of section A in FIG. 4;

[0044] FIG. 10: structure diagram of material propeller;

[0045] FIG. 11: structure diagram of long axis blade of the material propeller.

[0046] As illustrated in Figures above, 1 methane fermentation and inoculation homogenizing compartment; 2 methane fermentation compartment; 3 methane fermentation ejection compartment; 4 methane fermentation material inoculator; 5 methane fermentation feed distributor; 6 methane fermentation ejection balancer; 7 (7-1 to 7-7) methane fermentation material propeller; 8 methane fermentation stirring gas distributor; 9 assembly zone of methane gas; 10 hydrolysis feed inoculation and homogenizing compartment; 11 hydrolysis fermentation compartment; 12 hydrolysis ejection compartment; 13 hydrolysis inoculator; 14 hydrolysis feed distributor; 15 hydrolysis material ejection balancer; 16 (16-1 to 16-5) hydrolysis materials propeller; 17 hydrolysis gas stirring distributor; 18 assembly zone of hydrolysis gas; 19 methane fermentation feed heater; 20 hydrolysis ejector; 21 methane fermentation feeder; 22 hydrolysis gas circulation draught fan; 23 methane fermentation gas circulation draught fan; 24 hydrolysis feed compartment; 25 hydrolysis heating feeder; 26 hydrolysis feed heater; 27 hydrolysis feeder; 28 horizontal main partition; 29 parapet; 30 long axis propel blade; and 31 vertical main partition.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0047] The disclosure will be described in more detail below accompanying specific example with the preferred embodiments. But the disclosure is not only limited to this example.

[0048] The fermentation compartment technic design of the disclosure is no volume limitation, valid volume of methane compartment of the example is 5000 m.sup.3, height of material is 10 m (in planar graph 1, 2, cross-section diagram 1-1, 2-2, 3-3, 5-5), in practical application, whole compartment volume can be larger due to the material fermentation and agitation approach in the disclosure (In fact, if the design of fermentation compartment is cascade grid, another mechanical agitation approach can be used in single grid due to small volume of single grid material). The design of large compartment volume is realized by changing the number of grids and plane layout; so, this design has no technical barrier of the changing compartment volume.

[0049] The whole device of the example is shown in FIG. 1 and 2; the partial structure is shown in FIG. 3 to FIG. 11.

[0050] The fermenting materials is put in hydrolysis feed compartment (24) in proportion, then driven by the hydrolysis heating feeder (25), the materials move into hydrolysis feed heater (26) and being heated, next, it is going to hydrolysis feed inoculation homogenizing compartment (10) driven by hydrolysis feeder (27), with the combined effect of hydrolysis inoculator (13), hydrolysis feed distributor (14), and hydrolysis materials propeller (16-1), the materials are inoculated and homogenized and propelled in hydrolysis fermentation compartment (11), materials are stirred by compressed gas flow from hydrolysis gas stirring distributor (17) in hydrolysis fermentation compartment, in the meantime, with the help of hydrolysis material propellers (16-2 to 16-4) set in fermentation compartment, materials move forward slowly along the flow direction, the whole hydrolysis fermentation lasts for 5 to 6 days, finally, last hydrolysis material propeller (16-5) in hydrolysis fermentation compartment drive most materials into methane fermentation feed heater (19) through hydrolysis material ejection balancer (15) and hydrolysis ejector (20), a small amount of materials to hydrolysis feed inoculation homogenizing compartment (10) through hydrolysis inoculator (13) in order to finish the inoculation, that materials in methane fermentation feed heater (19) is being heated, and during the heating process, the hydrolysis acidize bacteria would be eliminated or inhibited at high temperature (60 to 65° C.).

[0051] Materials after hydrolysis, acidulation, and heating will enter methane fermentation feed inoculation homogenizing compartment (1) through methane fermentation feeder (21), with the combined effect of methane fermentation material inoculator (4), methane fermentation feed distributor (5), methane fermentation material propeller (7-1), the materials are inoculated and homogenized, then it is propelled in methane fermentation compartment (2). Materials are agitated by the pressure drift produced by methane fermentation biogas stirring distributor (8) in methane fermentation compartment, at the same time, with the help of methane fermentation material propellers (7-2 to 7-6) set in fermentation compartment, materials move forward slowly during the whole fermentation which lasts for 20 days, at last, the last methane fermentation material propeller (7-7) in methane fermentation compartment propels materials to methane fermentation ejection compartment (3) through methane fermentation ejection balancer (6), a few materials enters methane fermentation feed inoculation homogenizing compartment (1) through methane fermentation material inoculator (4) to finish the new round of inoculation of methane bacteria, in this way to realize circulation-fermentation.

Example 1

Compartment

[0052] It is made by reinforced concert structure; the valid volume of hydrolysis fermentation compartment is 1500 m.sup.3. The valid volume of methane fermentation compartment is 5000 m.sup.3.

Agitation

[0053] One of the key factors of dry fermentation of mixing material is agitation. The disclosure uses gas agitation, collecting the gas produced by fermentation, (hydrolysis waste gas of hydrolysis, methane fermentation mixing gas of methane), since the whole material packing height of the disclosure is much lower than another dry fermentation device so that normal fan can be used in gas agitation elevated pressure device, lower the industry cost while at the same time improve system stability, the uniform level of agitation is also improved.

Material Propeller

[0054] The disclosure uses a horizontal propeller with two blades under the condition of gas agitation. The material propeller is a horizontal propeller, and it is immobilized under the compartment driven by outer compartment. The horizontal propeller may include two long propel blades with counter rotation on two immobilized axes, during the counter rotation of two blades, the materials are transported from the previous gird into next gird homogeneously to make the materials with bad flow condition to flow forward homogeneously.

[0055] There are 7 material propellers set in methane fermentation compartment, 6 of these propellers have a 10 m axis, and 1 has a 4.2 m axis, there are 5 hydrolysis fermentation material propellers set in hydrolysis fermentation compartment, 4 of these propellers have a 5 m axis, and 1 has a 4.2 m axis.

Reaction Condition

[0056] The temperature of hydrolysis acidification is 33±2° C.; temperature of methane fermentation is 60-65° C.

Raw Material

[0057] 70% dewater sludge with 80% moisture content generated by sewage plant mixed with 30% crushed kitchen waste.

Device Ability

[0058] Input: 250 m.sup.3/d; hydrolysis fermentation stopping time: 6 days; methane fermentation stopping time: 20 days; gas produced by fermentation device: 25000 m.sup.3/d.