CA2116492A1 - Process for re-use of water-containing plant material - Google Patents

Abstract

Abstract In a process for re-use of water-containing plant material (1), the latter is pulverized and cellularly decomposed, preferably with the addition of water, using mechanical means (16). In particular, perforated disk, corundum disk, toothed colloid or hammer mills are suitable for cellular decomposition.
The plant material treated according to the invention can be selectively stored on an interim basis or applied directly to the soil or vegetative cover. In caring for qualitatively superior grass surfaces, preferably the cellularly decomposed material is also filtered or in some other way separated into a fibrous portion and a liquid portion. While the nutrient-rich, valuable liquid portion (cell contents) is being applied to the grass surface, the fibrous portion (cell walls) is re-used in a different way. The process can be implemented with stationary or mobile devices. In the latter case the device is used alone or in combination with a mower so that the grass clippings can be cut, pulverized, cellularly decomposed and re-applied in one or several operations.

Description

- ~l 16~92 Process for re-use of water-containing plant material Technical Domain The invention relates to a process for re-use of essentially wood-free, water-containing plant material, especially grass clippings, preparation wastes, and the like. In addition, the invention relates to an application and a device for implementing the process.

Prior Art The vegetative cover of heavily used grass athletic areas (soccer fields, playgrounds, golf courses, etc.) consists largely of pure grass. The high capacity to regenerate and resist wear reguired in almost all types of sports presupposes a sturdy blade mass and correspondingly well-developed root system of turf grasses. Turf surfaces are therefore regularly fertilized in order to promote growth of blades and roots, among others.
According to requirements specific to particular sports (durability, ball behavior, etc.), grass athletic areas must be regularly mowed during the growth period (March through October).
During a perlod of growth therefore considerable amounts of grass clippings are formed (green mass, 20,000 to 50,000 kg/hectare;
dry substance 2000 to 5000 kg/hectare3. Since on the one hand the grass areas must be fertilized, and on the other hand the . 2116~92 clippings themselves have considerable nutrient content, it seems ~ ;
simplest to leave the clippings on the surface and thus solve both the problem of disposal and also fertilization. This is admittedly possible in less demanding grass athletic surfaces with bioactive turf bearing layers. On highly sandy soils (for `
example, superstructures according to DIN 18035, part 4, or for greens) with low biological activity, the clippings however must . ~
be removed for considerations of athletic technique and cultivation.
In addition to the obvious advantages of leaving the clippings on the turf surface, the following disadvantages must also be considered:
a) The undesirable activity of earthworms is promoted.
b) Enrichment of the ground surface with green mass (raw humus) adversely affects water permeability or the water and air balance in the turf bearing layer in the case of mineralization which is not fast enough.
c) Matting on the base of the grasses is accelerated in the case of overly slow mineralization of blade mass.
d~ Overly large green masses or those unevenly distributed on the surface can damage turf grasses (rotting of the blanketed turf surface).
e) Grass clippings comprise an ideal nutrient medium for disease pathogens (fungal diseases, for example, fusarium asp., Corticium fuciforme, etc.). The clippings which lie on the surface of the vegetation promote the spread of diseases to the healthy blades of 211~92 ~ ~
.

turf grasses. Frequently a damp microclimate which promotes transmission of diseases from one blade to another is formed between the clippings and the ground surfase.

If therefore the clippings are picked up from the ground or directly collected by the mower, it is necessary to dispose of them in a suitable manner. Clippings contain a large amount of water (generally, 90% and more) and easily decomposable starches and cellulose as well as nitrogen compounds (amino acids, amides, protein, proteids, chlorophyll, etc.). On dumps or in transport -containers an intensive mineralization process begins a few days after cutting. The highly water-containing material collapses and under anaerobic conditions unpleasant odors are released from the putrefaction processes. As a result of burst cell walls, seepage water, heavily loaded with organic and mineral materials which endangers the soil and water can be formed. Therefore by law it is necessary to dispose of grass clippings within a day (for example, a rotting dump) or the clippings must be re-used accordingly (for example, composted). The following disposal options are known:
Dumping of clippings in approved dumps.
Advantages:
_ Convenient, but at present no longer responsible type of disposal for reasons of ecology and economy. -Disadvantages:
- Transport costs to the dump:

` ` 2 ~ 9 2 - Unnecessary burden on dump space which is becoming increasingly expensive and scarce;
- Loss of valuable organic substance and plant nutrients;
- High disposal costs (dumping charges).

Burning of the clippings in trash incinerators (KVA).
Advantages:
- Convenience, but at present no longer responsible type of disposal for reasons of ecology and economy.
Disadvantages:
- Transport costs to the incinerator;
- Need for outside energy for burning;
- Loss of valuable organic substance and plant nutrients;
- High disposal costs (charges have increased continually in recent years).

Composting.
Composting of grass clippings is at present the type of treatment which is most frequently attempted and practiced.
As a result of high water content, the clippings do not `
compost purely aerobically. Shortly after the compost heap is formed, a thermophilic putrefaction process begins in which the easily decomposable cell walls rapidly burst release the cell plasma, and thus undesirable amounts of seepage water are formed. The material quickly loses structure, collapses into itself and becomes wet. With the exclusion of air, putrefaction quickly begins, and ~ 2~16~92 unpleasant odors are released. Composting is only successful when the green mass is mixed directly after mowing with larger amounts of structure material (for example, shrub cuttings, tree bark). For an aerobic -putrefaction process, the compost heap must be regularly ;~
turned for a prolonged period of time. Plant- compatible finished compost, depending on the structure material used, is available (only) after a putrefaction period from 8 to 10 months.
Advantages:
- Ecologically efficient means of treatment of a biogenic ~-waste.
Disadvantages:
- Transport costs (transport of green mass to the composting plant and transport of the compost from the composting plant to the application site).
- High process costs for production of compost with low creation of value (grass clippings consists of more than 90% water).
- High plant, machinery and personnel costs for mixing the clippings with structure material, partially covered storage of the composted material, turning and sifting of the finished compost.
- Unequal energy balance: the amount of outside energy necessary for transporting and composting of clippings is demonstrably greater than the creation of value for 2~ 16~2 the humus and plant nutrients contained in the ~inished compost.
- The compost consisting of grass clippings and structure material cannot be returned to the material cycles of an grass athletic surface.
- For compost produced based on clippings, the corresponding sales channels must be found, for example, in gardening and landscaping.

Fermentation of clippings together with sewage sludge using biogas.
A~vantagas:
- Ecologically efficient type of re-use of a bisgenic waste.
Disadvantages:
- Transport costs (transport of green mass to the sewage treatment plant and transport of the sewage sludge from ~ `
the sewage treatment plant to the application site).
- Clippings loaded with few pollutants are mixed under certain circumstances with burdened sewage sludge.
- Sewage sludge cannot be returned to the material cycles of a grass athletic surface.
- High disposal cost (ARA charges are continually rising).

In practice, the current state of affairs in the disposal or -re-use of grass clippings and other biogenic wastes, for example, ' ' : : . .: .. ' ; ` ` ! `

~-` 2~16~92 preparation wastes (from large kitchens and food manufacture~
engenders in summary form the ~ollowing problems: ~ .
a) Storage and transport of biogenic wastes containing large amounts of water pose problems;
b) Conventional types of disposal or re-use (dumping, burning, composting, gasif~cation) are either not economical or not ecologically feasible;
c) Collection and removal of clippings entails undesirable breaking of (biological) material cycles.
d) Problems in use of compost and/or liquid fermentation .
end products which is economical and effective for ~:
: .
cultivation.

Description of the Invention The problem of the invention is to devise a process of the . ~
aforementioned type which avoids the aforementioned problems and ~ ~ :
which in particular can be used in the care of highly cultivated grass surfaces.
According to the invention, this problem is solved in that the plant material is pulverized with mechanical means and is cellularly decomposed.
Practical tests have shown that grass clippings can be broken down into extremely small parts, preferably in the natuially wet state or with the addition of water, using perforated disk, corundum disk, toothed colloid mills and hammer :~
mills. Plant cells which are rich in starch, cellulose and water are elmost c~mpletely destroyed with the releese of their ' , 2116~92 contents. A pulpy biomass is formed. The volume of the cellularly or colloidally decomposed material is 4 to 5 times less than that of the fresh green mass. This advantageous loss of volume requires smaller stacking and transport containers.
Pulverization and cellular decomposition of plant material (in the following also called colloidal decomposition) are designed to destroy the cell walls and allow the cell contents to escape. In that the material is very dramatically pulverized, it can later be placed finely distributed on the green surface or in the soil.
Total cellular (colloidal) decomposition of the plant tissue is not the optimum solution in each case. Technical or economic reasons can justify a smaller degree of pulverization (in this connection, reference is made to the mobile units described below). For this reason, the invention is not limited to destruction of plant material down to colloidal size. Under certain circumstances, pulverization with partial cellular -decomposition into the millimeter range can be adequate.
According to one advantageous embodiment, the pulverized and cellularly decomposed plant material is separated into its liquid portion and its fiber portion. This can be done with a filter unit, especially a filter belt press, a centrifuge or with other suitable separation device. The disadvantages which are caused by the fibrous cellulose material sticking to the blades of grass can be avoided in this way. The fiber portion consisting essentially of cell wall material is re-used separately.

:-, : ,,, :. ; ..: -- - . . . .. .

~6~92 Pulverized and more or less cellularly decomposed grass clippings can be used directly as fertilizer, finely diætributed or sprayed on~o the mown turf surface, or can be added to the soil. In this way the following advantages accrue:
- The biomass can be easily conveyed (with pumps), metered (with metering pumps, valves, etc.), and spread in the desired amount on the soil or injected into the soil (with suitable plowshares and/or spray nozzles).
- By destroying the plant cells cell plasma with the cell organelles contained therein is released and the cell walls which consist of cellulose are pulverized.
Mineralization of organic material therefore proceeds more quickly due to greater surface and impro~ed contact with bioactive soil material.
- Plant nutrients are more quickly available in cellularly decomposed biomass injected into the soil. ;
- Saving of commercial fertilizers and thus simultaneous reduction in the nitrate burden.
- No visual disadvantages as applied to athletic ~ -functions due to addition of the cellularly decomposed biomass to the turf.
The pulverized and cellularly decomposed biomass can furthermore be easily stored in open and force-ventilated containers (like force-ventilated liquid manure pits in ~
agriculture) over a longer period of time without causing the ~ -emission of unpleasant odors. Interim storage can be useful, for example, when the cellularly or colloidally decomposed biomass .i.: . . , ,: .. : .:. : . .:: ~ -.: .. ... ,. - ;::, :

2116~L92 - -cannot be immediately added to the soil after mowing the grass for reasons of weather or time, or when the colloidally decomposed biomass of a grass surface may not be reapplied to the same surface (golf greens, etc.).
According to one preferred embodiment, fertilizer or soil conditioners are added on a controlled basis to the cellularly or colloidally decomposed biomass before it is applied. The grass clippings returned to the material cycles, for example, are not sufficient to cover the entire nutrient demand of turf plants.
Some of the plant nutrients are needed to form root mass, can be fixed on soil parts (clay-humus complexes) in forms which are no longer available to plants, or are washed out. A nutrient shortage of this type is balanced in particular in the manner described in caring ~or grass surfaces (adding fertilizers, etc.). Of course it is not essential that the nutrient content of the biomass be increased in this way.
The biomass which has been colloidally decomposed and pulverized according to the invention can be handled very easily.
It can be pumped or blown and injected directly into the soil with a slitting device (rotary hoe, cutting plow, etc.) and metering pumps or can be spread on the turf surface. Thus all the disadvantages which arise when the clippings are left (untreated) on the surface are avoided. The colloidally decomposed biomass which is brought into direct contact with the ground is mineralized by microorganisms at an accelerated rate and without any notable adverse effect on plant growth. The prerequisites for this are significantly better in tha soil than -~-` 2~ 16~92 on the soil surface (moisture content and higher biological activity)~
- Closing of the material cycles in that the mineralized nutrients can be reabsorbed by the plants.
- Savings of up to 90% in fertilizers.
- The process can be carried out using small, compact units so that transport costs, charges (for dumping, incinerating, composting, gasifying) are completely eliminated.
In less demanding green surfaces the colloidally decomposed (or if necessary~ only highly pulverized) biomass can be applied directly to the vegetative cover, for example, with a sprayer, pressure drum (liquid manure drum) or a special drip or spreading -~
device. If application takes place, for example, shortly before precipitation, the extremely fine organic particles of the -biomass arè washed into the vegetative cover, in which the disadvantages as occur when the grass clippings are le~t on the turf surface are prevented. In contrast to the undecomposed grass clippings which remain on the vegetative cover, the biomass according to the invention is in direct contact with the soil material and is there~ore much more quickly mineralized. The aforementioned type of application (with liquid manure drum, ~;
etc.) is of course rather efficient and cost-favorable. ;
Foreign bodies, solids, rocks and so forth are removed from the waste material, preferably before colloidal decomposition, preferably in a water bath or quite generally by floating in a cleaning bath. In this way the required wetting is effected at 211~

the same time. Instead of water, under certain circumstances another suitable medium can be used. In this way, for example, the separation or cleaning process can be influenced in a controlled manner.
To improve the cleaning effect, water can be pumped, for example, from just below the water's surface through a number of nozzles (pointed upwards) into the water bath. In this way, that part of the water is replaced which has been removed together with the wetted waste material. The water's surface is swirled by the pumping-in according to the invention. In a simplified embodiment, water can be allowed from above into the water bath instead.
Depending on with what means the plant material is pulverized and cellularly decomposed, it can be advantageous or even necessary to wet the material to be pulverized. According to one especially pre~erred embodiment of the invention, the required liquid feed is effected by returning some of the filtrate or centrifugate obtained in filtering or centrifuging.
Thus, for example, in a mobile unit there can be a cleaning bath with relatively small liquid or water reservoir in which the cleaning liquid (water) lost in wetting the plant material to be cellularly decomposed is replaced by a corresponding amount of the liquid portion of the cellularly decomposed biomass which has been centrifuged or pressed out. However, return can be used not only in conjunction with a cleaning bath, but also quite generally to wet the material to be colloidally decomposed (in particular to facilitate mechanical decomposition).

21~(3~'3~

If the process according to the invention is implemented in ;~
an assembly which can be joined to a mower in order to immediately process the grass clippings and spread them again, ~;
then under certain circums~ances separation in a water bath would be too expensive. Depending on the application, separation of ;
foreign bodies could be entirely abandoned or it could be done by a suitable separation process, especially air separation. ~ ;
Wetting can thus also be abandoned.
Preferably the process is used for disposal or re-use of grass clippings and/or similar plant kitchen wastes. With the ~-~
corresponding addition of water (or liquid portion pressed out of the biomass, etc.) the process can also be used for wilted or dried plant material.
The process is not suitable for woody, high-lignin organic substances (wood, tree bark) as are used, for example, to produce porous soil conditions (peat replacement).
The preferred complete colloidal decomposition of plant material is carried out according to the invention with a ~ ~-conventional mill. ~n the past, they were used for producing cosmetic or pharmaceutical pastes, pulping fruits (apples, pears, bananas, cheese, etc.) or for preparation of soaps, pastes, fats, etc.
Reduction of the expenditure of labor and the number of steps (for example, by mowing the grass, cellularly decomposing the grass clippings and respreading the biomass onto the turf in one operation) can justify incomplete decomposition of the plant material. In addition to these especially preferred mills, for 2 1 1 6 '1 !~ 2.

example, in conjunction with spindle grass mowers, sickle bar mowers, rotary mowers, flail mowers, etc. any pulverization devices can be used which cut, strain, grind, puree, grate, shred, etc.
For cleaning in a water bath there is preferably a tank with a screw conveyor located above it. The screw conveyor delivers the material floating in the water bath to the mill. For example, there is a fill opening with a funnel above the screw conveyor. The waste material is emptied into the funnel with suitable metering. In the upper half of the tank there can be a water feed pipe with nozzles (openings) pointed upward to improve the cleaning action.
In addition, an automatic metering device is preferably provided. It consists, for example, of a material receiving hopper with a conveyor belt located on its bottom. In this way, a continuously operating system can be set up.
There is advantageously a force-ventilated container for possible interim. The biomass colloidally decomposed by the mill or similar item is stacked in this container for further use.
The unit can be used in stationary or mobile form. In the latter casa the different devices are preferably combined in a special vehicle. This vehicle can be used if necessary directly , together with a mower with a collecting device. However, as an independent vehicle it can also collect mowed grass, pulverize and cellularly decompose it and respread, separated or unseparated, onto the same grass surface. If filtering or similar activity is done, some of the filtrate can be returned, 2~16~'3~ -for example, to the cleaning bath (ston~ separator etc.), as already mentioned.
One especially preferred embodiment thus comprises a mower -~ -for cutting the grass, a catching or collecting device which immediately takes up the grass clippings, if necessary a foreign body separator (especially air separator) for eliminating foreign bodies, a pulverizing device in order to cellularly decompose the grass clippings as much as possible, and a spreading device for scattering or spraying the cellularly decomposed biomass. -Additional advantageous embodiments and combinations of features of the invention follow from the detailed description ;~
and totality of the patent claims.

Short description of the drawing The sole figure schematically shows a unit for treating and re-using grass clippings and similar residual water-containing plant material.

Embodiments of the invention Material receiving hopper 2 is filled with grass clippings 1 formed by mowing the grass. This hopper has on its bottom metering belt 3 which continually removes the grass clippings.
It is motor driven by drive 4.
~ Metering belt 3 delivers the grass clippings to mill feed unit 5. The latter has tank 8 with water bath 7, screw conveyor 14 located horizontally above it, and an opening with funnel 6 `
located above screw conveyor 14. The clippings fall onto screw ` ~16~32 conveyor 14 and past it into water bath 7 and are separated from specifically heavy impurities 12. The latter collect on the bottom of tank 8 and can be periodically removed through discharge opening 9.
Screw conveyor 14 is partially immersed in water bath 7 so that, as it i5 caused to rotate by drive 15, it can deliver grass clippings ll floating on the water's surface to the output of mill feed device 5 and thus to colloid mill 16. Clippings ll delivered from wa~er bath 7 are at the same time wetted in the manner required for colloidal decomposition.
Water is continually or intermittently supplied with pipe 10 installed horizontally in the upper part of tank 8. Water feed is controlled using motor driven valve 13. Pipe lO has a number of nozzles or holes pointed upward which cause swirling of the water area near the surface. It goes without saying that the swirling should not be so intense that the specifically heavier parts can no longer sink to the bottom.
Colloid mill 16 is located on the same geometrical axis as screw conveyor 14 and its drive 15. It pulverizes or grinds wet clippings 11 until the cell structures are destroyed (colloidal decomposition). Various known mills are suitable for this purpose:
- Toothed colloid mills (a toothed grinding set of stainless chromium nickel steel pulverizes the material~
- Perforated disk mills (a, for example, four blade cutter bar rotates at high speed just above a 2~16~2 perforated plate. The upper knife blades work against a stationary cam ring, coarsely pulverize the clippings and press them through the stationary perforated disk.
The ejector bar rotating under the perforated disk sucks the colloidally deco~posed biomass out of the cutting zone and delivers it to the mill outlet).
- Corundum disk mills (the waste material is pulverized to a fineness of roughly 1 micron between two ceramically sintered corundum disks into a thin liquid to pasty biomass in a continuous procedure. A rotor grinding element rotates with high speed against the stationary stator grinding element. In the gap formed ~ -~
by the two corundum disks, the waste material is colloidally decomposed with high shearing, cutting and impact forces).
These mills are sold, for example, by FRYMA-Maschinen AG, CH-4310 Rheinfelden, Switzerland. Drive 17 of colloid mill 16, drive 15 of screw conveyor 14 and drive 4 of metering belt 3 are controlled in a manner coordinated to one another by common control circuit 27. There is likewise a pump 19 which delivers the pulpy and pumpable cellularly decomposed biomass from colloid mill 16 to a desired site, for example, to loading station 21 or storage tank 22 (line 18). Water feed for water bath 7 can likewise be controlled by control circuit 27 via motor operatPd valve 13 according to the amount processed.

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r.:

1~
" ~116~92 According to one preferred embodiment, at the end of line 18 there is selector valve 20 with which the biomass can be sent alternately to a loading station 21 or storage tank 22.
Storage tank 22 in~ludes open container 23 and motor (motor 25) driven stirring apparatus 24. If necessary, biomass can be removed via drain cock 26.
By means of the stirring apparatus, a ventilation fan or similar apparatus, anaerobic fermentation processes in open container 23 are prevented (unpleasant odor development).
If it is desirable that the nutrient content of the colloidally decomposed biomass be additionally supplemented, or if any auxiliary agents are to be added, this can be done either in storage tank 22 or only in the corresponding assembly before spraying (for example, in a tanker truck or in the spreading device).
According to one preferred embodiment, there is filter belt press 28 (of conventional design) downstream of pump 19. This press presses the liquid portion which is collected in filtrate collec~or 30 out of the pumpable biomass. Filter residue 29 is ~ ~-separated for purposes of separate re-use. Pump 31 pumps the filtrate to storage tank 22. Selector valve 32 enables switching from nonpressed biomass to pressed biomass.
Separation of the biomass is recommended especially in caring for demanding sports grasses (for example, golf greens).
It. is here that it will be possible to apply the grass clippings to the same turf surface once again.
With unfiltered biomass the following problems can arise:

-` 21~.6~92 If cellularly decomposed grass clippings are sprayed in liquid form (suspension) onto ~he mowed grass surface, the cellulose fibers (pulverized, fibrous cell wall material) continue to stick to the blades in the manner of a felt-like coating. Only the liquid (cell plasma plus cell contents plus water) seep almost invisibly into the turf or into the surface of -the ground. Cellulose fibers adhering to the blades make the grass slippery in the wet state and decompose only poorly due to lack of contact with the ground. Dried fibers impart a yellow aspect to the sod and promote increased formation of grass felt. --~
Tests have shown that cellulose fibers which adversely -~
affect the grass surfaces can be most easily separated by filtration or centrifuging from the liquid cell contents.
The biomass which is formed following mill 16 is thus continuously divided into two groups of material. The filtrate . .
or centrifugate (which contain the plant nutrients N, P, K, Ca, Mg, Fe in different solubility stages which determine value) of i~
the cellularly decomposed grass clippings, in contrast to the unseparated biomass, can be easily spread with the most simple spraying devices, uniformly and without visible residues on the ~-grass surface. The proteins, carbohydrates, fats, salts, vitamins, hormones and various other compounds contained in the cell plasma reach the soil and are made available to the plants there by microorganisms within a few hours.
The wall substance in green plants or the residue obtained during filtration or centrifuging consists of cellulose. The carbon-hydrogen-oxygen compounds, in contrast to the cell plasma, ~ ' : ~ . ~ . ' ' . ': , : . ` ' . . ! ': . ,, ,, ~

~ 16~2 contain no substances valuable for plant nutrition. The filter residues are therefore sent for composting, for example. During the putrefaction process, the organic substance decomposes into carbon dioxide gases (Coz) and water.
The pressed out or centrifuged cell wall material, compared to untreated grass clippings, represents a fraction of the initial volume and weight. The amount of material from a grass athletic area can thus be stored or transported in an extremely small space and causes neither undesirable seepage water nor unpleasant odors of decay.
As already indicated several times, the process can be carried out not only with stationary, but also with mobile machinery and equipment. The latter make transport to a central location (for cellular decomposition) and afterwar*s transport back to apply the biomass to the grass surface superfluous. The grass clippings can then be cut, pulverized, cellularly decomposed, and applied in one operation.
For this reason, a mower of suitable type (reel mower, sickle bar mower, rotary mower, flail mower, etc.) is equipped with a device which catches the cut grass directly from the cutting tools (for example, reel) without residue. Aspirators (fans), pick-ups, conveyor belts, screws and others are suitable for catching. These devices are known in the most varied designs.
In principle, foreign bodies can be separated as in the stationary version. Carrying along a water tank does make the special vehicle large and heavy. Therefore preferably air 2 ~ 2 separators or aspirators are used as separators. In golf greens which are cut with reel mowers, the number of foreign bodies is negligibly small. Therefore, in an equipment combination to be used for this purpose, separation of foreign bodies can be abandoned completely. Then, for example, appropriately durable pulverizing devices which are not vulnerable to foreign bodies can be used.
If some of the filtrate is to be returned in the embodiment shown in the figure, there should be a return line which branches after pump 31 and empties into tank 8 (stone separator). Return can take place by intermittent switching sr by continuous branching of a partial flow of the filtrate. A controllable valve can be provided to meter the returned liquid portion; the valve is controlled depending on the liquid level in the cleaning bath.
The pulverizing device can be supplied with grass clippings using different conveyor elements according to take-up of clippings beginning with the cutting tool of the mower (for example, screw conveyor as in the stationary embodiment or a fan).
~ o pulverize the grass clippings, in addition to the aforementioned mills, devices are also used quite generally in which organic substances or plant tissue and cell matexial can be suitably pulverized, smashed, decomposed, broken open, etc. For continuous cellular decomposition of the grass clippings in -mowers, therefore rotating blade shafts with opposing blades, cutting or grinding rollers rotating in opposite directions as -~
:

' ' , ' ~ ,' ~ '' 2 1 ~ 6 ?~ ~2 :
well as aspirators, fans and so forth which cause the material to be pulverized in addition to pneumatic material delivery can be considered especially advantageous.
Pulverization of the grass clippings with or without water (or biomass filtrate and so forth) is conceivable.
In the assemblies under discussion here, the biomass must be respread onto the mowed grass surface in the same operation. The pulverized grass clippings tend to form clumps, especially without the addition of water. It is therefore of decisive importance that the biomass can be placed on or in the soil in a form as finely distributed as possible. If the biomass is liquid or can be pumped, it can be spread by spraying or sprinkling nozzles as well as drip systems. If the grass clippings are pulverized without the addition of water, a pulpy mass with relatively high consistency is formed which can no longer be pumped and sprayed in liquid form. Preferably therefore rotating disintegrators ~for example, toothed shaft) and/or fans for material atomization are used.
The machines and devices described can be driven by electricity from the grid or a generator as well as with internal -combu~tion engines and hydraulic motors. The latter is especially of interest when the devices form integrated parts of a special vehicle for mobile use. The metering device, foreign body separation and mill feed can be controlled automatically, depending on mill performance.
The invention is of course not limited to the aforementioned embodiment.

~ ., -- 2 1 1 6 ~ 9 ~
In particular the mill feed device need not be arranged axially in front of the mill. -~
Removal of foreign bodies can take place differently or it -can even be entirely omitted. Metering by means of a metering belt represents only one of several possibilities.
Instead of several individual motors, a single motor to which the devices to ~e driven are joined via suitable ~-transmissions can also be provided. This is advantageous, for example, when the devices are installed permanently on a truck or form part of a special trailer.
According to one especially preferred embodiment, the colloidally decomposed biomass which may have nutrients added as necessary is introduced directly into the (slit or scratched) soil. Scratching or slitting of the soil necessary for this purpose takes place preferably with a device as described in EP~
0 466 658.
The invention was described based on recycling of grass clippings for athletic grass surfaces. The invention of course is not limitad to this especially preferred application. Thus, there are other possible applications in agricultural, vegetable ;
gardening, community, commercial and/or industrial re-use of biogenic wastes.
At present, for many communities, disposal of kitchen wastes poses major technical and economic problems. In handling or in ecologically and economically feasible re-use of kitchen wastes, essentially the same problems occur as in grass clippings.
Kitchen wastes treated with the process according to the ~ ~ -., -, . ,. -,, : : , , . :, . .. , ., -. :
.. ~: .
. .
; , :. , - .. .

2 11 6 ~ 9 2 invention can be used like the colloidally decomposed grass clippings. In addition to the aforementioned advantages of the invention, it should be emphasized that colloidally decomposed kitchen wastes can also be added to the soil during the cultivation season, for example, to rows of corn, sugar beets and vegetable crops, without adversely affecting plant growth. -Costly interim storage as is the case with compost is largely eliminated.
Kitchen wastes are generally unattractive. Their components are pulverized using the process according to the invention until they are unrecognizable; this is a great advantage to the user.
Likewise, biogenic wastes containing large amounts of water, similar to grass clippings, from agriculture (for example, "
harvest residues) and vegetable gardening (for example, preparation wastes) as well as from trade and industry (for ~`
example, the food industry, catering trade) can be used with the invention.
The green mass which grows along roads and highways is `~
heavily burdened with pollutants (for example, lead), therefore its disposal or re-use as roughage or provender is extremely ;~
problematical. Care of green belts, slopes, etc., is at the same time very costly and uneconomical and ecologically questionable.
The gathered material must be mowed, loaded, transported and dumped at high mechanical and personnel cost.
The material gathered from road edges, slopes and so forth can be returned in an economical and ecologically useful manner to the material cycles of green areas of all types at the origin . .

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2 ~ 9 ~
according to the invention by spreading colloidally treated green :-mass directly on~o the mowed green surfaces without adversely :~
affecting plant growth.
In summary, it can be stated that by means of the invention, a completely new, ecologically and economically advantageous process for disposal or re-use of water-containing green wastes has been devised.

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Claims (20)

1. Process for re-use of essentially wood-free, water-containing plant material, characterized in that material (1) is pulverized with mechanical means (16) and cellularly decomposed.

2. Process according to claim 1, wherein the pulverized and cellularly decomposed plant material is separated into a liquid portion and fiber portion.

3. Process according to claim 1 or 2, wherein perforated disk, corundum disk, toothed colloid or hammer mills are used as mechanical means (16).

4. Process according to one of claims 1 through 3, wherein beforehand plant material (1) is purified floating in cleaning bath (7), by means of which the addition of water is effected at the same time.

5. Process according to claim 4, wherein to improve the cleaning effect, liquid from just below the surface is brought by a number of nozzles into cleaning bath (7).

6. Device according to one of claims 2 through 5, wherein at least some of the separated liquid portion is returned as liquid feed to the plant material to be cellularly decomposed.

7. Process according to one of claims 1 through 6, wherein after cellular decomposition, auxiliary agents, especially fertilizers and soil conditioners, are added.

8. Process according to one of claims 1 through 6, wherein the colloidally decomposed material is applied directly to the soil.

9. Application of the process according to one of claims 1 through 8 for disposal or re-use of grass clippings and/or other plant kitchen wastes.

10. Application of the process according to one of claims 1 through 8 to the care of grass surfaces, grass clippings of the grass surface being used as plant material and the biomass produced therefrom being at least partially applied again to the same grass surface.

11. Device for implementing the process according to claim 1, characterized by mill (16) for pulverization and cellular decomposition of plant material (1).

12. Device for implementing the process according to claim 1, especially according to claim 10, characterized by a feed device with a tank (8) for cleaning bath (7) and screw conveyor (14) located above tank (8) for delivering plant material (11) floating in cleaning bath (7).

13. Device according to claim 12, characterized by a fill opening which is located above screw conveyor (14) and which is provided especially with funnel (6).

14. Device according to claim 12 or 13, characterized by liquid feed pipe (10) which is provided with nozzles pointed upward and which is located in the upper area, preferably at least at half height.

15. Device according to one of claims 11 through 14, characterized by material receiving hopper (2) with metering belt (3) for metered delivery of material (1) to cleaning bath (7).

16. Device according to one of claims 11 through 15, characterized by force-ventilated tank (22) for interim storage of the treated material.

17. Device according to one of claims 11 through 16, characterized by a means for separation of the pulverized and cellularly decomposed plant material into a liquid portion and a cellulose fiber portion.

18. Device according to claim 17, wherein there is a return line in order to return at least some of the separated liquid portion to the plant material to be cellularly decomposed.

19. Mobile device for implementing the application according to claim 10, preferably with a mower for cutting the grass, with a catching or collection device for catching or collecting the grass clippings, with a pulverization device for executing at least partial cellular decomposition and preferably with a spreading device for applying the cellularly decomposed grass clippings to the grass surface.

20. Device according to claim 19 with foreign body separator, especially an air classifier for eliminating foreign bodies before pulverizing the grass clippings.