CZ401299A3 - Composting device of continuous operation with independent aerating zones - Google Patents

Abstract

A continuous composting device (10) equipped with separate aeration zones (Zl, Z2) so that air circulation occurs in these zones and that the bacteria do not spread through the composting corridor (12). All the zones are equipped with a supply fan (46A, 46B) and suction fan (48A, 48B) while sucking the pressure higher than the supply air pressure, so aerating the gases do not spread to the corridor space (12). Similarly leaked removes the system from the system in such a way that it does not come into contact with its processed All gas and water recirculation only takes place in the relevant zone.

Description

Technical field

The present invention relates to a waste composting device and a waste composting process.

BACKGROUND OF THE INVENTION

The importance of composting waste has increased at least after the public has become aware of the unsuitability of exporting waste to the open landscape in the context of environmental conservation. Traditional heaps of compost in the back yard have replaced various newly developed industrial methods and systems for small-scale composting.

Proposals have been made to develop an automatic composting facility in which waste is fed by one side, with the finished compost leaving the other side. These devices, especially in large-scale composting of waste, face the problem of passing waste through the device body.

A similar facility consists of a corridor with a waste bin above one end and an outlet at the end of the other. At the beginning of the device at the waste container there is a pile driver, which at intervals pushes and moves the waste material on the solid floor of the corridor. This pile driver tends to stifle the waste material to such an extent that it is prevented from aerating, which is necessary to produce good compost.

• 9 • 9

-299 99 • 9 9 • 9 999 • 9 9 • 9 9

99

9 9 9

9 9 9

999 999

9

99

In another waste composting system that allows the necessary aeration, the movement of waste through the corridor is mediated by drawing the netting. However, this system works with individual batches and a new batch of compost can only be prepared after the original batch has been completed.

Another common problem in conventional waste treatment systems is odor. For health and aesthetic reasons, it is not considered desirable to use open composting systems, since rotting garbage can be a cause of health problems and their odor is very unpleasant.

Also, the removal and treatment of unpleasant odorous gaseous components has caused considerable problems in the past. From the closed composting plants, the resulting gases were only discharged into the surrounding area.

Recently, US patents 5,409,831 and 5,551,969 have been granted to James Wrigt for a 24-hour composting facility that includes a composting corridor with a discharge of harmful and unpleasant odor gases. The waste is placed in the corridor of the device on perforated bowls arranged in series in a row. The bowls move along the corridor in such a way that when the first bowl is completely filled, the bowl is moved and the empty bowl is brought in its place. Composting takes place continuously throughout the corridor, supplying both water and air. The mixing takes place in at least one part of the corridor. This device has the advantage over the prior art that fluids and waste gases can be removed, and the gases can be filtered before being released into the atmosphere. In the treatment of waste, the temperature rises to a level suitable for forming the composting mixture and this temperature can be high enough to eliminate the bacteria present. However, in some parts of the device the temperature is lower and there is also a risk of bacteria penetrating the composting device through liquids or air.

00 00 00

000 0 0 00 0

0 0 0 0 ·

0 0 000 000

0 0 0

0000000 00 00

-3 • 0 0 0 0 • * 0 • 0 · • 0 00

Since the composting device in question can be intended for normal use by unprotected individuals, it is desirable to be safe and sterile. Waste destined for processing in commercial composting plants can have a wide variety of origins and be contaminated with bacteria. For this reason, complete destruction of bacteria is important.

The resulting product of established composting plants, including those according to which the aforementioned US patents 5,409,831 and 5,551,969, do not always meet the criteria mentioned.

The Applicant's patent proposes a solution to the problem of continuous composting systems for the processing of food waste on a small or large scale, with or without the addition of other worse materials such as wood shavings or even rubber. It is a composting facility in which contamination by bacteria is minimized.

SUMMARY OF THE INVENTION

The components of the continuous composting plant of the present invention are:

closed elongated corridor with start and end, waste entry in the start area, compost exit in the end area, at least one composting zone in the start area and one composting zone in the end area, first self-regulating means to aerate the first composting zone and disperse injected aeration gases in the first zone and the second • 999 ·

-499 99 9 9 9 9 9 9 9

99

9 9

9 9

999 999

9

Self-regulating means for aerating the second composting zone and dispersing portions of the injected aeration gases in the second zone.

Another part of the device may be one or more additional composting zones with self-regulating aeration means. The first and second zones may be separated by intermediate zones which overlap with them, but are intended to minimize the ingress of air from one zone to the other.

The recirculation of a portion of the waste gases and gases used in the aeration may be controlled by the aeration self-regulating means. This recirculation can be a solution to the problem of unpleasant odor of food waste. Recirculated gas and fresh air volume rates can be computer controlled. However, it is important that gas recirculation is limited to the space of any composting zone.

The composting device may type correspond to the devices described and claimed in US Patents 5,409,831 and 5,551,969. For example, the device may include:

a conveyor belt extending from the floor of the corridor and guided along the entire length of the corridor, serially arranged transport pans displaced on the conveyor belt, each transport pan being equipped with a bumper frame for displacement and a perforated support surface enabling aeration of composted matter on the pan The pile driver is positioned to press against the bumper frame of the nearest transport bowl.

In the area of the start of the corridor there is a means for mixing the waste to be composted. It includes a hopper in the form of a longitudinal cylinder with an open mouth and 9

9 9 ··

9,999 9 · · · 9 9 9

9

99 99 9

-599 99 99

9

9

9,999,999

9 9

9999 99 99 longitudinal base convex towards the outer surface of the hopper. The hopper is located in the upper surface of the corridor below the waste inlet and can be tipped along its own longitudinal axis. In the first position, the open mouth of the hopper is directed upwards and waste can be poured into it. In the second position the hopper mouth faces down, the hopper is emptied and the waste is poured into the waste inlet. The hopper is equipped with mixing screws to mix the waste.

The hopper is equipped with a gear on the outer surface, by means of which it can be tilted

The mixing screws should be rotated in opposite directions to thoroughly mix the hopper contents. The open top of the hopper may be provided with a lid to prevent the odor from escaping in the hopper. The lid can be tilted to allow waste to enter the hopper. If the lid is trapped on one side of the hinge, it can automatically raise when the hopper is lowered.

The side walls of the corridor may be parallel and a pair of rails may be part of the means of transport.

The trays may be generally rectangular in shape and their width (i.e., the dimension between the bumper frame and the opposite edge) should match the pivot length of the pile driver. Transport pans should be equipped with sliding sliding elements to allow the pans to move along the corridor transport path. Similarly, the rails already mentioned may have a smooth surface over which the bowls can be moved. However, it is preferable to provide the sliding surface of the transport bowl itself as it is easier to control the degree of wear. The tray surface should be in the form of a perforated metal sheet, mesh or similar perforated material.

The exit from the corridor can be equipped with a cover that can be opened by the pressure of the transporting bowl, so it can be a door freely caught on the hinges. In the hallway can

44 ·· 44

4 4 4 4 4 5

4 * 4 4

4 444 444 • 4 4 44 4444 44 44

-644 44

4 4

4 44 *

4 ·

4 4

44 may be a means for mixing composted waste, for example in the form of cylinders disposed across the passage, provided with waste mixing vanes. The waste mixing means is expediently located in an intermediate zone that separates the first and second composting zones, or in a high temperature section of the passage where there is little risk of bacteria being contaminated with the subsequent sections of the passage. The blades can be tilted to one or the other side of the corridor to better mix the waste. There may also be two waste mixing rollers located one above the other in said sections of the corridor. Each roller may have at least one blade curved toward the axis of the roll that will collect waste in one direction and at least one blade curved in the opposite direction that will roll the waste in the opposite direction. The adjacent vanes may preferably be curved in opposite directions. The area of each blade should represent a plane that is at right angles to the cylinder axis. The adjacent blades of the individual rollers should preferably be curved in opposite directions so as to direct the waste in the opposite direction and to mix the waste in a transverse direction in the corridor of the device.

Immediately after the waste mixing rollers, the still and unused waste is sprinkled with water in a quantity corresponding to the composting needs. At least one sprinkler should be routed through the upper part of the corridor. It would be even more appropriate if the tubes were at least two, close together (i.e. at a distance of about 20 to 30 cm). Of course, in a smaller composting device, the distance between the sprinkler tubes will be smaller. The seepage water in each zone may be collected in separate individual chambers and recirculated, but only in its respective zone.

The present invention further provides a process for composting food waste comprising:

transfer of waste to the composting passage through an inlet in the area of the front end of the composting plant, «4

Removing compost through the outlet at the rear end of the corridor, aerating the waste separately in the front and rear zones, and recirculating a portion of the volume of gas used, only in the zone where the gas has been used.

Brief overview of the drawings

An embodiment of the invention will now be described by way of example with reference to the accompanying drawings.

Figure 1 is a schematic side view of the composting device of the present invention.

Figure 2 is a top view showing a water and air supply system. Figure 3 shows the composting device of Figure 1 viewed from one end.

Figure 4 illustrates a sliding transport pan for use in a composting device, such as shown in Figure 1.

Figure 5 shows another embodiment of a sliding transport bowl for use in a composting device, such as shown in Figure 1.

Figure 6 illustrates in detail the sliding transport tray housed in a U-shaped frame.

Figure 7 shows the air flow through the device.

Figure 8 shows a possible way of water and moisture penetration through the device.

• · · · • · φ φφφφ φφφφ

ΦΦΦΦΦ φ · φ · · · · · · · ·

ΦΦ ΦΦ φφφφ φ · ··

Examples of embodiments of the invention

The drawings show a composting device 10 comprising a corridor 12 with an upper portion 13 and a mixing hopper with a hopper 14 that extends from the beginning 16 of the upper portion 13 and which is usually tightly sealed to prevent the escape of harmful and odorous gases. The waste is lifted by the conveyor and poured into the hopper of the mixing container 14. The end 18 of the corridor 12 is equipped with a compost outlet 20. The outlet is usually tightly closed. Corridor 12 is provided on both sides with a supporting transport frame 22 to receive sliding transport trays 24, which are progressively displaced in the longitudinal direction of the transport frames.

The top transport bowl 24 is located in the frames 22 below the hopper of the mixing hopper 14. The waste is conveyed by a conveyor to the hopper of the mixing hopper 14, from where it is dispensed into a shipping hopper 24 located at a suitable depth (approx. It is then moved by the pivot of the pile driver 26. The pile driver 26 has a pivot such that it moves the bowl 24 forwards, leaving sufficient space for the next bowl. After displacement of the transport bowl 24, the pile driver is tilted and another bowl is inserted into the space thus formed between the pile driver and the filled bowl. The plurality of trays and the length of the corridor should be such that the composting is completed when the tray 24 arrives at the end 18 of the corridor. Thereafter, the compost is removed by means of a conveyor and the bowl returns to the inlet end 16. The displacement of the empty transport containers can be performed manually or can be automated. In the latter case, each bowl that leaves the outlet port 21 can be seated on the conveyor and conveyed to the inlet port 23.

The length of the corridor and the size of the transport basins should be such that a daily dose of waste can be placed on one pan. We believe that, under good conditions, a fortnight should be enough to create a quality compost. inside the composting facility

there should be fourteen shipping bowls. The operation of the composting device will be described in more detail in connection with its individual parts.

The waste deposited in the hopper U may be food waste, which is preferably mixed with some additional material, such as newspaper or wood shavings. Food waste can also be mixed with bits of rubber. This is a possible way of using rubber waste, which currently poses considerable problems. Pieces of 0.5 to 2 cm rubber can account for up to a third (or more) of food waste.

Each transport bowl 24 consists of a frame and a perforated surface 28 that allows air to access the waste to be treated. The apertured surface 28 is positioned above the frame. The trays are transported to the upper end of the corridor 12 via the inlet port 23. The trays 24, which are moved into the corridor by the swing of the pile driver 26, push the tray 24 underneath and move forward. In this way, the bowls are moved through the passageway and ejected out of it through the outlet port 21, which is tightly closed in addition to the bowl exit point to prevent gas leakage. Because the bowls are subjected to considerable pressures (due to the fluctuations of the pile driver 26 pressing against the bowls frame), the bowls frames must be designed to withstand these pressures. The side wall 30 of the frame on which the front side of the pile driver 26 is pushing must be of sufficient height. The pile driver 26 pushes the upper frame through the inlet port 23. In fact, the side walls 30 of the frame need not be too high. It is only necessary that they have certain vertical surfaces on which the front side of the pile driver will push and be able to withstand the impact

The other two side walls of the bowl, which are longitudinally located in the passage of the composting device, are as rigid as the side walls 30. However, these longitudinal side walls may not face the full impact of the pile driver.

A pair of opposing longitudinal side walls 30 of the bowl frame are seated in the strips 22 in the walls of the corridor 12. The transverse profile of the strips 22 is U-shaped with a base 35

-10 9 9 9 9

9 9 9

I · 9 9

9 9

999 999 fixed in the wall 32 of the corridor. The base 35 of the bar 22 is wide enough to accommodate the entire height of the bowl frame. The bowl frame lies on the U-profile rail support portion 37a and is covered from above by the rail profile cover portion 37b.

Corridor 12 and transport trays 24 can be sized to match the amount of waste to be treated. Since, under good conditions, the composting process can take 14 days, it is possible to use one transport container per daily dose of waste. If 100 kg of waste is to be treated on a daily basis, the dimensions of the transport container and the corridor dimensions must correspond to this load. Also, the pile driver has to be able to set in motion a wide variety of trays by its dimensions and pressure. It should be pointed out, however, that the composting device of the present invention can be adapted to operate on a very small scale or industrial scale on a large scale. Mechanical adjustment and technical equipment of corridors and transport basins of appropriate dimensions should not cause any problems for the expert.

It is apparent from drawings 1 - 3 that the passageway is purposefully divided into two aeration zones Z1 and Z2. Three or more aeration zones are possible. The operation of two or more or more aeration zones is generally identical. A temperature sensor 32 is located in both zones Z1 or Z2.

Both zones Z1 and Z2 are equipped with aeration systems, which include vertically positioned tubes 42A and 42B, which are routed outside the side wall of the corridor. These tubes, via fans 46A and 46B, supply air from the outside down below the level of the trays 24 to separate chambers 43A and 43B of both zones Z1 and Z2. From the chambers 43A and 43B, air is blown in the respective zones through composted waste. The bottom of the tubes 42A and 42B may be equipped with an additional fan. To extract air with the gases produced in both zones during composting, the top of the corridor is equipped with exhaust fans 48A and 48B. Part of these exhaust gases can be fed back through the tube 45 as part of the air to be aerated

-11 · * · · · · 9 9 9 9

9 9 9 9 9 9 9 9 9

9 9 99 9 9 9 9 9 9 9 999 9999 (Λ 9 99 individual zones. To prevent the spread of bacteria throughout the area The exhaust gases have a relatively high oxygen content and it is possible that in addition to the oxygenation itself, the recirculation of the exhaust gases increases the lightening effect of the aeration. led by a sterilizer 50.

The arrangement of the tubes 42A, 42B and the chambers 43A, 43B with respect to the exhaust fans 48A, 48B of both zones must be such that air and gas circulation always takes place only in the respective zone. It would indeed be desirable to separate the aeration zones Z1 and Z2 with an intermediate zone (XI) in which no aeration occurs or only to a small extent. Air circulation should be carried out in such a way as to avoid significant aeration of the intermediate zone XI. The exhaust gases are discharged to the biofuel 36 and dispersed into the atmosphere. The suction performed by the suction filter 48 is greater than the pressure of the air blown by the inlet fan 46, which in turn results in the zones of zones Z1 and Z2 remaining separate and not overlapping. The pressures can be controlled by a computer 68.

In the middle zone, it might be desirable to install agitators 60 to provide some lightening of the composting mass in areas without airflow.

The water is supplied in the form of a water curtain from the diffuser rod 102, which extends across the corridor 12. The circulation of the water can take place in the same way as the air circulation in the space of any zone. For example, water from the dispersion rod 102 in zone Z1 may seep through composted waste into the flat chamber 104 below the trays 24. The floor 106 of the flat chamber 104 slopes towards the lower channel 108 well below the bottom of the bowl 24 into which the water enters. This can then be sucked off by pump 110. If it is desired to recirculate this water, the flat chamber 104 must be and

-12 Channel 108 divided into individual chambers Channel 9 divided into individual chambers 104A, 104B (see drawing 8) and channels that would correspond to the respective zones Z1 and Z2. Each zone must be equipped with its own pump 110 so as to minimize the likelihood of bacterial transmission by recirculating water. Each pump 110 is equipped with a return line 112. The amount of recirculated water is controlled by the computer 68. In addition, the pump piping must be equipped with a valve to prevent water from returning so that clean water does not flow into channel 108. It is important that water is dispersed immediately behind mixers 60 until the waste is freshly lightened and unused. Therefore, the dispersion rod 102 located downstream of the mixer 60 is more important than the dispersion rod 102 before the mixer 60. Experience has shown that installing two dispersion rods 102 at a distance from each other is preferred.

At the rear of the last zone 22, two screws 62 are vertically positioned to transport the finished compost to the side passage of the corridor. In the connection, the compost drops the extruded screws 62 onto the conveyor and is then removed by the sliding door 20.

The whole process can be controlled by a computer 68 which calculates and controls the ratio of polluted gas and fresh air to the aeration supplied to both zones Z1 and Z2 depending on conditions such as the temperature in the composting space, and which can also control the opening and closing of the inlet and exit doors. The inlet and outlet doors can generally only be opened when transporting waste to or from the facility. In addition to these two options, the corridor is tightly closed. The inlet and outlet of the trays 24 allow an inlet and outlet port, but when the trays are in the corridor area 12, the frames effectively block and close both ports. The computer 68 may also ensure that the aeration gas pressure (with or without the polluted gas fraction) is maintained at a lower level than the polluted gas suction pressure. If the pressure in the corridor area is kept lower than the external atmospheric pressure, any unpleasant odor will not escape into the environment due to any leaks in the equipment.

• · · ·

-13 9 9 9 9 9 9 9 999 99 4 99

As the trays move along the corridor, the volume of composted waste increases. At the beginning of the corridor, the transport bowl can be loaded with waste, for example, so that the load is 30 cm from the ceiling of the corridor. During the shifting of the bowl, the volume of this load can be increased by 40%, for example by using agitators or by using additional longitudinal screws which allow the longitudinal mixing of the composted mass without jeopardizing the entire waste treatment process. This mixing can help to make the surface of the material to be treated evenly, it also allows greater aeration of the composted material, aids the process and speeds it up.

The choice of the longitudinal dimension and the interior space of the corridor depends entirely on the user's requirements. In our case, the whole facility was described for convenience only as a corridor that holds fourteen transport bowls, one bowl sufficient for the daily dose of waste. In the case of regular supply of waste, its daily quantity is not decisive. If the user expects, say, 100 kg of waste per day, the system can be modified so that each bowl holds the 100 kg. In a device of this type, there is no need to check whether the load is larger and whether a new transport pan is already needed. However, the user will certainly welcome the possibility of introducing an additional transport bowl in the event of an irregular waste stream only if the bowl 24 directly below the container 14 contains an adequate amount of waste. This can be decided visually or with the additional automatic means installed to alert the user of the need to introduce another transport tray.

Fourteen days or fourteen shipping basins are not decisive for the length of the corridor. Under favorable conditions, the compost can be prepared in a fortnight, but with sufficient strength of the trays and sufficient pile driving force, the compost can remain inside the corridor longer. It is obviously necessary to extend the corridor beyond this minimum length.

-14 ..... P.ťSftS-fysZ · © · · · f f f f f f f f f · · · · · · · · · · · · · · · · · · ·

Claims (10)

PATENT CLAIMS 1. A continuous composting plant (10) with separate aeration zones, comprising: closed longitudinal passage (12) with start (16) and end (18), waste inlet (14) at the beginning (16) of the plant, 'compost outlet (21) in the region of the end (18) of the plant, front composting zone (Zl) in the region of the start of the corridor and the rear composting zone (Z2) in the region of the end of the corridor, the first aeration means (42A, 43A, 46A, 48A) for aerating the front composting zone (Z1) with the aeration gases; a part of the polluted aeration gas volume is used for recirculation, the second aeration means (42B, 43B, 46B, 48B) is used to aerate the rear composting zone (Z2) with the aeration gases, and the aeration gases move in the rear composting zone; a gas conveyor belt (22) located above the floor of the corridor; thinned along its length, a series of transport trays (24) which are moved along the conveyor belt, each trays being equipped with a bumper frame, which is pushed by the pile driver, and a perforated support surface that allows the waste material to be aerated on the tray, -15 • · · · · φ φ · φ · e • • • • • • Idlo φ φφφφ φφ <φ pile driver (26) with a pivot in the direction of the longitudinal axis of the corridor, pendulum length is equal to the selected length of the transport trays, the pile driver is positioned so that its pivot pushes characterized in that said first and second aeration means comprise: air inlets (42 A 46A) to the front of the chamber (43 A) below the conveyor belt (24) in one of the zones, means for guiding air (46A, 46B) through the inlets (42A, 42B) to both chambers (43 A 43B) exhaust fans (48A, 48B) positioned to direct gases from the chambers (43 A, 43B) to one of said zones (Z1, Z2), a control means (68) that maintains the exhaust gas pressure at one of said zones higher than the pressure of the injected aeration gas, said zone is provided with means for recirculating a portion of the volume of the polluted gas through the respective air supply (42 A 42B) to this zone. The composting device of claim 1, wherein the composting device comprises at least one other aeration zone with means for aerating the zone, wherein the movement of the aeration gases takes place in the composting zone and part of the volume of contaminated aeration gases is used for recirculation. • 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 99 99 99 99 99 99 -163. Composting device according to claim 1, characterized in that the front zone is separated from the rear zone by an intermediate zone (XI) which is not provided with aeration means. A composting device according to claim 1, characterized in that it is provided with pipes for discharging the polluted gas from the exhaust fans into the filter. Composting device according to claim 1, characterized in that all the trays have a substantially rectangular shape, the distance between the buffer frame and the opposite wall of the tray being equal to the pile length of the pile driver. Composting device according to claim 1, characterized in that the corridor of the device is equipped with means for mixing the composted waste. A composting device according to claim 1, characterized in that it is provided with a means (102) which supplies water to the waste in an amount suitable for composting. -17 * «« 17 17 17 17 17 17 17 17 17 17 17 Composting device according to claim Ί, characterized in that it comprises: wherein the water supply means is in the form of at least one spray tube (102) which is transversely located in the upper part of the passage and sprays water in the form of a water curtain. Composting device according to claim 7, characterized in that there is a waste collecting chamber under the conveying trays. se Composting device according to claim 9, characterized in that it is equipped with a pump for sucking water soaked from the collecting chamber. Composting device according to claim 9, characterized in that, beneath the trays, there is a separate collection chamber (104A, 104B) in each composting zone with means for recirculating water from the chamber to the respective spray tube.