FI77832C - Anaerobanläggning. - Google Patents

Description

FIELD OF THE INVENTION for transfers.

In the treatment of wastes or other organic substances based on methane fermentation, mixing is often difficult. The volumes handled are large and the ingredients are inhomogeneous. As a result of poor mixing, the mass to be treated deposits in the reactor tank, methane bacteria do not mix with it, it heats up unevenly, etc. A surface crumb and a bottom layer form in the reactor. Eventually, the reactor has to be opened and the deposits formed removed, which is laborious and costly. On the other hand, excessive mixing must be avoided as it requires energy and may even interfere with the function of ethane bacteria.

In order to achieve efficient mixing, the methane fermentation reactors are equipped with either pumps of sufficient size, propeller or paddle stirrers, agitators or gas stirrers. The reactor itself can also be mobile, in which case its contents are mixed. However, pumps consume a lot of energy, as do propeller mixers. Horizontal and vertical axis agitators save energy, but usually require a cylindrical tank to extend to all parts of it. Gas mixing, with or without a mammoth pump, requires an expensive gas compressor, and is therefore only relevant in large units.

Rectangular, box-shaped reactor spaces would have several advantages over cylindrical ones. They take up little space when placed side by side, their lighting is simple from several different materials, and they are easy to divide into compartments. In wastewater treatment, rectangular basins are therefore e.a. reasons for popular landing pools. In this case, they are equipped with drags, the function of which is to transfer the sludge settled to the bottom of the basins to a collection chute or pocket for further processing. The drags do not aim to mix the mass to be treated, so their speed is always adjusted to a laminar flow rate of 2,77832, which means a maximum of 0.03..0.06 a / s when handling low viscosity liquids.

It has also been proposed to install traction units in anaerobic reactors in order to move the mass to be treated from one compartment to another (EP 56.202, lines 5.6 and 29) or to leave the reactor space (EP 56.202, line 35). Such a drag has no confusing properties. Surface corpus control has had to be arranged with separate impeller or blade-shaped members. In DE application 2855389, page 8 and Fig. 1, a chain-driven transfer member (Förderorgan) is proposed for transferring a surface body under a partition between the reaction and removal compartments. Again, the transfer member has not had a confusing purpose. A chain drive, which is known per se, is in the EP application

52,049 used for a completely different purpose, namely to transfer large filter pieces evenly from one reaction space to another.

It can be clearly seen from the above-mentioned applications that the drags described therein perform only conventional transfer tasks and that the reactors described in connection therewith have had to be supplemented in color with auxiliary means for breaking the surface crust.

They are not designed to be suitable for mixing between the active biomass and the feedstock, nor are they suitable for it.

It has now surprisingly been found that it is possible to equip a rectangular reactor silo with a completely new element which, on the one hand, acts as a pulp-transfer drag and a surface crusher, but on the other hand The invention is based on a towing blade which changes its mode of operation depending on where in the reactors it is located.

The features of the invention appear from claim 1. An example of the implementation of this new type of tow is shown in Figures 1 and 2, the numbering of which is referred to below. Figure 1 shows a side view of a methane fermentation reactor equipped with such a drag and Figure 2 shows a side view of the drag.

77832 3

The box-type reactor space (1) is provided with a feed pipe (2) and an outlet opening (3) for the pulp or sludge to be treated, as well as a gas-tight lid (4) with gas collection piping (5). The interface between the pulp to be treated in the reactor and the liquid accumulating at its top is marked with the number (6). Inside the reactor, gears (8, 9, 10, 11) are mounted on the shafts (7) in pairs, on which hang two pancake chains (12) forming a closed loop. At least one shaft (7) communicates with a rotating device located outside the rector wall, which causes the hook chains to move. The rotating device, which is known per se, has been omitted from the figure for the sake of clarity. The direction of rotation of the hook chains (12) is shown in the figures clockwise, but in the embodiments of the invention it may also vary according to a certain program.

In addition, one or more drag beams (13) are suspended from the hook chains, which rotate with the hook chain. The side profile of the tow bar and its attachment to the hook chain is shown in Figure 2. The tow bar is substantially bent at an angle, giving it a gutter profile. The tow bar is articulated (14) to each hook chain. In addition, the edge of the beam is fastened to each hook chain by means of articulated support strips (15). In addition to the glazing skill, the beam may also have other shapes, and the side profile of the beam does not have to be the same throughout. The beams also do not have to be available. The attachment of the beam to the hook chain may also differ from the above. It is essential that a gutter-like part has formed in the beam.

As the drag beam (13) travels by the hook chains (12) on the section between the gears (8) and (9), it collects the material that has settled to the bottom of the reactor basin against its spool and transfers it to the collecting chute (16) from where it can be removed from time to time. This collection chute gets automatic! also any sand among the pulp to be treated, which is thus removed from the reactor. After moving to the section between the gears (9) and (10), the drag beam slowly lifts the material left in its gold finish from the bottom. The support strip (15) prevents the tow bar from bending downwards. After passing the ratchet wheel (10), the drag bar is turned upside down, causing the material in the bellows of the bar to fall down, effectively mixing with the rest of the surrounding material.

Claims (7)

4 77832 The drive wheels (10) and (11) are arranged so that the drag bar with the portion between them runs on the surface (6). In this way, it efficiently transfers the foam accumulating on the surface and the surface crust to the outlet (3), whereby the surface deposits cannot enter the filtration east. After passing the section between the haaaas wheels (11) and (8), the drag bar starts a new round all the way to the bottom. Part of the towing and mixing mechanism «is not located or moves in the center of the reactor either. Thus, this space remains free and can be provided, if necessary, with large members or structures, such as partitions, landing boosters, expansion devices, wall-supporting cross-beams, porous filter pieces or plates. See all the devices, structures and lifes mentioned above are already known. However, as a new solution to the prior art, a transverse partition (17) can be arranged in the reactor, for example between the gears (9) and (10), so that the beam has to move upwards as it rises up. The partition wall (17) can also be used as a support for the gears (9) and (10), in which case they do not necessarily need shafts (7). A reactor for the anaerobic treatment of sludge and liquid basses and for the recovery of the gases formed, which is substantially box-shaped and has means for introducing (2), discharging (3,16) and transferring the mass to be treated, as well as for collecting and discharging the gases formed. devices (4, S), characterized in that it is equipped with a mixing drag mechanism, the drag beams (13) of which are gutter-shaped in cross-section so that they collect and transfer the sludge deposited at the bottom of the reactor to the beginning of the reactor the surface of the pulp to be treated, and when turned around its path allow the slurry to fall freely downwards, thereby causing the slurry and the feed pulp to mix at the beginning of the reactor. 77832 5 Reactor according to Claim 1, characterized in that the agitating drag beams (13) of the drag mechanism are arranged to run in their upper position so as to move the surface crumb accumulating on the surface (6) of the pulp to be treated towards the reactor outlet (3). Reactor according to Claim 1, characterized in that the agitating drawbar beams (13) are supported by articulated support strips (15) connected to the drawbar chain (12). Reactor according to Claim 1, characterized in that one or more partitions (17) are arranged in such a way that, either together or together with the end walls, bottom or liquid surface of the reactor, they form a gap whose clearance is such that the beam beams (13) can reach to pass through them. Reactor according to Claim 1, characterized in that the partitions (17) arranged therein act as supports for the shafts (7) of the gears (8,9,10,11) of the towing mechanism. 1. A reactor for anaerobic treatment with slamaktiga and flytand substantia and tillagatagande av därvid upststäende gaser, which is preferably used as a source and with an anchorage for inerting (2), utilization (3.16) and inerting with a sizing in the same way of the upstream gas (4,5), the transducers of the sheave and the shear mechanism of the scraper (13) are ranformed in the genomic crest as well as the shear of the reactor sample upplyfter där det i rännän samlade slammet account närheten av ytan pä den massa som skall behandlas, och läter slammet fritt Falla ned när de svänger sig runt under sin Gäng, varvid de i reaktorns främre parti ästadkommer uppblandning av slammet och den inmatade massan.