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woensdag 16 april 2014

Principles and some food for techies.

Hendrik asked me to write a post about scaling up his method for composting grasses. I asked him why he wanted this. Why would he want to worry about a big compost project, when he himself has not the money for it? And, he himself does not want to scale up, because he is very satisfied with his method and his small project on our Monte in the Alentejo.


"It will not leave me," he said. "I think of new things, especially at night, when I cannot sleep. Maybe I can not sleep because I think of new things. I do not know why, and I do not want to know actually. Because coming up with new thoughts and creating new things is just fun. Even when I am not planning to do it all myself. Composting for me is a nice topic to let my imagination run wild.
If you want to compost on a larger scale, the first things you think about is machinery, shovels and containers. And for me, I do not want to be involved in that."
"So it's not just about what you are doing now, but more about the things that could be possible?"
"Yes, I want to bring up a few options, that I figured out. Everything actually is about the immersing of materials. For the rest any entrepreneur is very much capable to make up there own mind about how to set up a composting project. Every situation is different. And there are situations that I can not look into. But there are the things I know, because once we had to deal with it on a daily basis. I know in what tempo a conveyor belt must run from A to B. And I know how fast a drum must rotate, in order to avoid things crashing. But about that, I do not want to talk here. These are details which will only be addressed if the machines are to be purchased or made. And it is quite a bit to set up a project. You know how this is...
In professional composting various social rules and forces come into play. Sometimes it is not at all about the production of compost. First it is about regulation, finance, employment, social importance, social environment, politics. Then it is about supply, marketing, nature, grassland management, habitat, just name it. And only then we think about technique, or about composting. And actually I want to talk about the latter alone. Because that is nice. Some food for techies. Everything else, is just difficult... most of the time.
Think about it. Who will pick this up? For example, when we look at our surroundings. Who will take the trouble to mobilize a complete village community for this idea of composting? To compost the grasses, that are available everywhere around us? Just look around you. All the grass is eaten by animals. Everyone here has cattle. Sheep, cows. And just about everyone has a pig in the meadow for piglets, for meat."
"Nice though. Better than in Holland, where all livestock is kept inside."
"And the land, the soil is impoverished."
"Yes, that is true."
"Cattle pays off very little. And not because the meat is not good. If you buy a sheep it is just as expensive when you sell it again, big or small. The only thing that pays off a bit, is the lamb that is born. Such things happen all over the world. You know how this works. People, farmers make no money. And nothing happens. Nothing changes in the thinking of people. Nothing changes in their way of practicing."
"But what then?"
"I do not know. Socially, I mean. Technically, I know. Yes I do. If life was so easy then we all knew what to do. It would be technically very well possible that people learn to make compost from the grasses, that now are eaten by sheep and cattle. People could start with composting these grasses that grow on there lands. Start a vegetable garden of there own. And not so much later they could provide the complete village and neighborhood with compost ánd with food. I see this before me, how it could be. Only I cannot initiate it. I do not have that preview function, we noticed. I cannot tell them. Firstly because I do not come from this place. I do not speak the language of the people. This has nothing to do with the few words Portuguese I speak. I like these people very much and they like us. But I am just not the person to do this talking... I am a stranger in this land. A guest. 
So that is why I want to see it written down. In a public blog. Then everyone can read it and think about it. If possible. Or do something with it, even better. And that writing you can do."
"Ah, yes."
"But," Hendrik said. "But, I do not want to blame the people here, that they stick with what they have. This here is a poor farmland. It has never been a rich area. In the early days, in another economy, people could make some money with land and cattle. In addition with some grain, some wine and olives, a vegetable garden... And one had a good life. But if things change around you, you cannot blame a farmer that he is not switching from one circumstance to another easily. A farmer is originally conservative. He goes on, despite setbacks. He puts worries aside and goes to work."
"And now... ?"
"Think about it. For example, you are sitting on an oil field and you do not know. In this manner I see this country. There are resources for grabs. There are many possibilities with this land. I see a lot of compost there. I see it before me, what you should do. Maybe because I come from another land? Then you look on the objects. You are not in there midst."


The basics.

Hendrik: "The immersion barrel (grafting barrel) is the most important part of my composting method. So that will be my main focus here also. Besides we need a place to drip and a place for temporarily storing, before the actual composting begins. The latter should be done in a place where lots of grafted material can be piled up well. And it must be possible to protect the whole composting place well from weather influences.

Meanwhile I, for myself, decided to only continue with the composting of dried materials. So in the future I leave out the composting of wet and fresh grasses as much as possible. Fresh grasses must be dried. Also, garden and kitchen waste must be dried first. I am in the fortunate position that the grasses on our land dry on stem. I cut it and then drag it up the mountain for storing and composting. This is what I think is the best, because with this hay I achieved the best results in the last year.

If one would like to apply my current way of working to larger quantities of hay, I think the storage of the harvested hay will take a relatively large space. It occurred to me that I needed a lot of space to store the hay that I had harvested during the summer."

How to work it out.

"The grafting and draining of large volumes of hay can be done in four units. I think of four (concrete) bins, linked to a dirty water pump. Each unit must also be provided with a grid, where underneath, the surplus of grafting fluid can be collected and pumped out.
As follows:
The 1st. unit: (day 1): For the immersion of hay with grafting fluid, where (after 24 hours) the liquid is pumped out into a still empty unit, unit 2. Then the hay will remain for at least another 2 days in this unit for draining, until it is transported to the final storage for composting.
The 2nd. unit (day 2), 3rd. unit (day 3) and the 4th. unit (day 4): Just like in unit 1, the immersion of hay, draining it and pumping it to the next empty unit. From 1 to 2, from 2 to 3, from 3 to 4 and from 4 back to 1. Again, the grafted hay remains in the units to drip for 2 days, until it goes to the final storage for composting.
Here the cycle is complete. So, when the grafted hay will be removed from unit 1 for storage and composting, then unit 2 follows to be emptied one day later. And so on. A rotation model.

In order to maintain the hay under the level of the grafting fluid gratings are used. These may be aggravated, depending on the mounting structure of the grating. All units are equipped with a lid, or a hatch cover, to close them off from outside influences.

At this moment I use multiple containers for dripping and temporary storage of the grafted hay. This is actually born more out of necessity, because my immersion barrel is not big enough. I can only graft relatively small amounts of hay in one time. To gain enough mass, I need to store the grafted material before to compost it in a big bag.

In addition to the four units for grafting and draining, we still need two containers.
1 container for the storage of manure, which is soaked before use. And a 2nd. container for the storage of the manure mixed with water and the recirculated leachate. This is also the mixing container in which the leachate is pumped back out of the units.

The actual composting takes place in a construction that resembles a horizontal silo. It consists of a horizontal place with two long side by side fixed walls, and a separate back wall. The back wall may be moved to the other end of the silo. Thus, one can load and unload the silo on the front and rear end. The place must be hedged well from weather influences.

When the composting process is completed, the compost can be shredded. By shredding the compost it will be brought into contact with air. It comes from low-oxygen conditions, therefore aeration is necessary, in order to homogenize it and improve the structure. Then the compost can now be stored to mature. Subsequently, it can be sieved in order to be used in the end."


Composting unit. Option 1.

"The following drawing shows a sketch with a small basic system, like I could set up on our Monte if I wanted. Here I proceed on the assumption that all the work is done by hand."


"I stick to the making of my small hay packs, after hay-making. This makes the processing easier. I place a basket of wire mesh in the middle of a unit, through the bottom grid, to the bottom of the unit. So I can easily pump out the grafting fluid with a simple hand pump. I pile the hay packs in the units, round the basket. This I cover with a grate and heavy/weigh it with stones. Then I fill the unit with grafting fluid, until the level is above the upper grate. A day later I can pump the grafting fluid, through the basket, to the next unit. Then the hay can drain for 2 days before it goes to the composting silo. The silo should be deep and high enough to heap up the hay high. I use a partition in the silo, to stack at a time, in neat parts. The whole, I cover with a plastic cloth.

Of course this can be done with more material and on a larger scale. And also in a continuous process with more mechanization. We have thus gained the necessary experience in our company. I know now that some things need to be resolved first before it will work. We need to solve several problems within this mechanization, but what I will do here is give some options. Real techies will fill in the gaps, for sure."

Composting unit. Option 2.

"In order to bring the hay in good contact with the grafting fluid, we must be sure that it is not tangled and that is has no lumps, before it goes into the immersion unit. To disentangle it, is the main issue that should be resolved first. The finest where if all stems were laid in the same direction. However, an ideal situation one will never reach. But either way, the thing that approaches the ideal the furthest, is a drum with blades, as in a grass drying factory, in conjunction with how wool is carded. The drum should run faster than the conveyor belt, with which there is only a small pick of hay to be taken. The feed to the drum could happen with a walking floor. Or a conveyor belt on an air floor will come in handy also. The conjunction of grafting units and (manure/leachate) containers has a fixed pump installation."

An example of a cutter drum:


In this video we see grass, that already is cut very short. We ourselves either, have to deal with very long grasses or hay. This makes handling far more difficult. For this purpose one should rather use more speed than strength. Shredding materials mechanically mean a greater investment in machinery, than when the work is done by bacteria. It is a consideration between the purchase and maintenance of machines versus waiting for bacteria that take their time to complete their work.

Hendrik: "In the startup of our company, we used to use a manure spreader, we had eventually turned into something that looked like a wool carder. The inlet ran slower than the blades belt, so no lump of hay was more to be seen. This was our first experimental design. However, an agricultural mechanization is not suitable for a continuous process. For that you need a firmer industrial mechanization. A farmer always uses his machines temporarily. They are built with this intention. You should be able to connect it to a tractor and it should be able to ride also, in most cases. And still they stand still with problems. We have been through a lot with this thing before it went to work. But it was cheap."


Composting unit. Option 3.

"The immersion units are loaded by an installation that I call 'hay carder'. This carder includes a walking floor, or a conveyor belt between sidewalls. Behind this a cutter drum, a drum with blades/knives, that feeds an other conveyor belt. This belt is located below the cutter drum and moves slowly back and forth, with which the unit is loaded gradually. This installation (hay carder) can be moved from unit to unit.

During charging, the unit does not contain grafting fluid yet. This will be added later. A grid keeps the hay under the level of the grafting fluid. These are hinged to the units (think of a hatch or door) and can be closed, in such a way that they can withstand upward pressure. These immersion units are hedged to lock out outside influences.

After dripping, the units can be unloaded by a crane with a gripper. It can load a kipper (behind a tractor). Either a shovel can put the grafted material into the composting silo.

These units are located within a roofed situation. The number of grafting units can be expanded as desired, and/or enlarged.

The silo for composting can be built as high and long as desirable. It can be covered with a high roof, which allows a tractor with wagon, or a shovel doing its job. In a  further step, the roof could be lowered, in order to protect the silo optimally, during non-working days.

One must also take into account the fact that a crane can stack higher then a shovel can. A simple fact, with major consequences."

Composting unit. Option 4.

"Then one can also think of a system, in which the material stays within a unit. So even after it has been grafted and drained. When the supply of materials happens only once or a few times a year. And when one has time and space enough to wait until the composting process has been completed.
The construction of the unit is the same. Also the process of loading, grafting, dripping and pumping is the same. But after this the material continues to compost within the unit. Here, too, of course, several units are conceivable. The unit(s) is(are) covered to lock out sun, wind and rain."

Artists impression of a composting site in Holland (1993).



Composting unit. Option 5.

"This option wants to achieve a continuous supply and transit in a long but not too deep immersion unit. Instead of immersing materials into a stationary circumstance, here we base the process on a literally 'moving immersion' in a continuous process.

The deeper the unit, the more material there is in it, and the higher the upward pressure will be. In order to limit the upward pressure, we can make the unit not too deep. When one wants to immerse a lot of volume, one can find a solution in the width of the unit. And also, the longer the unit, the more volume one can immerse, and the more time one can take before the materials reach the end of the unit. So the better the grafting will be.

Here again we apply the principle of a cutter drum. It is supplied by a walking floor or a conveyor belt between sidewalls. The 'hay carder'.

The drum feeds the immersion unit, which is filled with grafting fluid. The hay should then disappear below the level of the grafting fluid. This is done by spraying, or with a carrier, or with both.

And now this new thing I have figured out: On the level of the grafting fluid, a walking floor I call 'walking sealing', which is situated above the (to be grafted) hay, to keep it below the level of the grafting fluid. This 'sealing' is provided with teeth, which are hydraulically movable, up and down. Stabbing them in the mass of hay and pushing it slowly towards the exit. As parts of the walking sealing retreat, the teeth pull back from the mass (up), then they come back down to stab into the hay to push the mass further. And so on. This will be easy because the mass in floating in the grafting fluid.
The timing of this event is equal to the time it takes to graft the hay thoroughly. So the tempo will be very slow. How quickly it can be done, the practice must tell. I can not see it now. Because the hay is already bruised and frayed by the cutter drum, the immersion time is relatively shorter than the 24 hours that I take for this now."

How a walking floor works, an example:



"The immersion unit has an ascending backside. Here the hay mass is pushed up. As soon as it rises above the level of grafting fluid it is picked up by a second walking sealing (with hydraulically driven teeth also), which pushes the hay over the edge of the immersion unit, on a grid."

An artists impression of a hay carder + immersion unit (1993):



"A shovel can bring the grafted material to a composting silo. This silo is provided with a sloped surface towards the center, with a discharge chute and a grate on the entire length, with at the lowest point a sump. "

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With some creative changes to existing resources, we can achieve a lot. We have been told many times that we would have to register or patent our ideas and inventions. We believe that patenting, the development of good inventions just gets in the way. This while without a patent, in itself, it is already hard enough to set up a project. We are already so used to the assumption that new features can solely be implemented in the form of a business model, it is just not credible anymore if it just comes from people. Many useful things disappear into a drawer eventually, while further it is not possible to acquire a patent, when it concerns a natural process, like composting is. And that is just fine. Because a good idea needs to be made public. Then every one can use it, share it.
Hereby, our ideas are now 'registered' while showing them on the world wide web. Use them if you please. And when you use them, please tell us. Not because we want to interfere. But rather because we want to follow it with interest.

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Stella.


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