HRP20020069A2 - Device for continuous fermentation of solid biological waste - Google Patents

Description

The field to which the invention relates

This invention relates to a new technology for the decomposition of solid waste of biological origin, through a process of continuous fermentation, which produces energy-valuable methane gas that can be used to heat rooms or produce electricity.

Technical problem

When breaking down solid waste of biological origin by fermentation, the problem is that the process is discontinuous. The waste must be covered so that air cannot penetrate into it, and drainage pipes are placed inside it to collect the energy-valuable gases produced. The problem is that this process is discontinuous, i.e. it lasts for some time, after which the waste must be removed, the drainage pipes must be removed, and then the whole process must be repeated, which requires a lot of work and time.

State of the art

The problem of fermentation of solid biological waste such as solid manure, sawmill waste and municipal waste rich in material of biological origin is solved by making large piles of waste into which, when adding waste, drainage pipes are placed to collect energy gases. When the pile of waste is piled up to the desired size, the waste is covered so that air cannot penetrate inside, and that the resulting gases cannot escape uncontrolled. Fermentation lasts from several months to several years, which depends on the size of the waste and its humidity. The finer and wetter the waste, the faster the fermentation. After fermentation is complete, the pile of waste must be decomposed, disposed of in another place, and rebuilt.

During manure fermentation, the manure is filled into special chambers inside which drainage pipes are placed, and when the chamber is full, it must be hermetically sealed. After a few months, when the fermentation process is over, the chamber is opened and the fermented manure is taken out. In colder regions, at the beginning of fermentation, it is sometimes necessary to heat the mass in order to start the fermentation process.

In large landfills for municipal waste, drainage pipes are laid in layers, the fermentation process is very slow, it lasts up to 30 years, and after that the drainage pipes remain in the landfill.

Presentation of the essence of the invention

The primary goal of this technology is that in a small space, with very little human work, the fermentation of biological waste takes place continuously and quickly.

The secondary goal is to enable the processing of municipal waste without first separating biological waste from inert waste.

A further goal is to enable purification of biologically polluted wastewater from suspended particles.

The advantages of the technology will be shown in the following description.

The device for continuous fermentation of solid biological waste includes a construction consisting of three parts. Fresh biological waste is added to the first part of the structure, the entrance room, where the waste is immersed in water. The mass of waste and water slides down diagonally and gradually enters the second part of the structure, which looks like a slanted pipe and where the fermentation process takes place. This fermentation tube is narrowed at the top so that the gas produced during the fermentation process is concentrated near the top of this fermentation tube. The water in which the waste is immersed serves as a seal that prevents the gas from escaping uncontrollably through the entrance and exit room, and also the water accelerates the fermentation process. The gradually fermenting mass slides down and comes to the exit room where the elevator takes out the fermented waste. As much fermented waste is taken out as much fresh waste can be added to the entrance room. The gas that is concentrated in the upper part of the fermentation tube exits through the gas tube under a pressure that depends on the difference in the level of water(s) in the fermentation tube and outside it. The gas is led to the reservoir or to the consumers and it is necessary to maintain it under constant, approximately equal pressure. If the gas is drained off slowly, the gas pressure can increase so that the water level inside the fermentation tube drops, which can lead to an uncontrolled flow of gas through the inlet and outlet rooms. The fermentation process takes place in water, so fermentation is much faster and lasts several months, which also depends on the size of the pieces of biowaste. In colder regions, at the beginning of work, it is necessary to warm the mass slightly and after that the heat is constantly maintained at the required level.

If the waste is cleaner and has a higher content of biological waste, the slope should be lower, and if there are larger pieces of inert waste in the waste, the slope of the bottom should be higher.

Brief description of the drawing

The accompanying drawing, which is included in the description and forms part of the description of the invention, shows a longitudinal section of the device and helps to explain the processing technology. The drawing shows that waste and water are added to the entrance room (1), that the mixture of waste and water slides towards the fermentation tube (2), and the exit room (3), from where it is removed by an elevator (5). It can also be seen that the gas created in the fermentation process collects in the top of the fermentation tube (2) where it goes further through the gas tube (4).

A detailed description of at least one way of realizing the invention

Referring to the drawing, it can be seen that the device for continuous fermentation of solid biological waste consists of an entrance room (1), into which fresh waste is added. This entrance room is filled with water so that the fresh waste is immersed in the water. The submerged waste settles and gradually slides into the fermentation tube (2), where the fermentation process takes place without the presence of air. In the fermentation tube, with gradual fermentation, the mass continues to slide slowly towards the exit room (3). After several months of fermentation and gentle sliding, the fermented mass enters the exit room (3), where it is removed by an elevator (5). The speed at which the mass slides through the entire device depends on how quickly the mass is removed. When removing, care must be taken not to remove waste in which the fermentation process is still ongoing, which can be seen by the gas bubbles that rise to the surface of the water in the exit room. If bubbles appear, the extraction process should be stopped immediately and continued only after a few days.

The water level in the entrance room (1) and the exit room (3) is the same and should always be maintained at the same level. The water level inside the fermentation tube (2) is lower because the gases created in the fermentation process collect at the top of the tube and push the water downwards. Here, the water serves as a seal that prevents the uncontrolled escape of the produced gas. The more gas there is, the higher its pressure and the lower the liquid level in the fermentation tube. The pressure depends on the difference in the liquid level in the fermentation tube and the level in the inlet and outlet rooms. At a certain pressure, the gas must be released towards the storage or consumers through the outlet gas pipe (4). If the gas was not removed at a certain pressure, the liquid level in the fermentation pipe (2) would continue to drop and the gas would begin to flow out uncontrollably through the entrance and exit rooms.

Method of application of the invention

In this way, the invention of a device for the continuous fermentation of solid biological waste enables the use of different biological waste for the production of energy-valuable methane gas.

Manure is the best material for fermentation, and fermentation lasts the fastest.

Municipal waste, which represents a major ecological problem in cities, can be processed directly, without prior separation, with this technology, provided that it does not contain soluble chemical compounds harmful to anaerobic bacteria that cause the fermentation process. It ferments all the waste that can ferment, and the remaining inert waste and plastics are subsequently separated from the fermented waste by washing.

Municipal sludge and other wastewater (if not poisoned with harmful chemical compounds) rich in biomass can be purified with this technology by filling the entrance room (1) with straw and filtering the sludge through it. As soon as the surface of the straw is filled with sludge, we add a new layer of straw or similar material. The mixture of straw and sludge sinks and settles down, and the filtered water goes to the side from the entrance room.

Claims (4)

1. The device for continuous fermentation of solid biological waste consists of a structure inside which the addition of biological waste, fermentation of waste, conversion of biowaste into fermented biowaste, and its removal from the structure takes place, and the entire process indicated by this is enabled by an element called a fermentation tube ( 2) which is slanted, inside which the fermentation process of solid bio-waste immersed in water takes place and which has a narrowing in the upper part that prevents the uncontrolled outflow of gas. 2. Device for continuous fermentation of solid biological waste according to claim 1, characterized by the fact that the waste mass slides into said fermentation pipe (2) from the entrance room (1) into the narrowed, entrance opening of the fermentation pipe (2). 3. A device for continuous fermentation of solid biological waste according to claim 1, characterized by the fact that from the said fermentation pipe (2) the waste slides downwards towards the exit at the lower end of the fermentation pipe where there is an exit room (3) from which the fermented takes the waste out. 4. Device for continuous fermentation of solid biological waste according to claim 1, characterized by the fact that at the highest point of the fermentation tube (2) there is a gas tube (4) through which the gas produced in the fermentation process is discharged.