WO2000043137A1 - A process for transforming waste into building material and raw material of organic compositions fertiliser - Google Patents

Abstract

The invention relates to a process for transforming waste into building material and raw materials of organic composition fertiliser, including following steps: 1) the waste is successively fed into a hermetic vessel, heated to 120-220 °C, pressurized to 3-15 atmospheric pressure, and kept for 1-5 hours in this condition, so that the waste is decompounded, sterilized, deodorised and reduced in volume; 2) the waste having been treated in the first step is depressurized and sprayed out, and is separated into two parts to be used for building material and raw materials of organic composition fertiliser; 3) the said two parts are separately dried out, magnetically separated, crushed up, and collected.

Description

 Method for processing garbage into building material raw material and organic compound fertilizer raw material method

■ fe ship

 The invention relates to a technology for treating urban domestic garbage.

current technology

 At present, there are several methods for the technical treatment of municipal waste, which are summarized as follows: The first is the landfill method. It is to build a pit field several meters deep from the ground on a large area of land in the less populated area. The bottom of the pit field is paved with bentonite to form a thick impervious layer, and an appropriate number of pipes are set to collect the generated Landfill leachate and biogas. After the garbage arrives, the dump site is gradually piled up. When the site is filled, it is filled with earth and rock and compacted. All the garbage is eliminated. The advantages of this method are: short construction period and large processing capacity. However, the unavoidable disadvantages are: 1. The land occupation is large, and because the biogas and geothermal heat generated after the fermentation of the waste, and the large amount of plastic and glass contained in the waste are difficult to decompose, the land after the landfill cannot be used for hundreds of years. For greening and farming, it is not advisable to build houses on it because of poor foundation. 2. There is a hidden danger of groundwater pollution. Once the impervious layer is damaged, as in an earthquake, water pollution is inevitable. 3. The construction investment is large, but the life cycle is not long. For example, to build a landfill with a land area of 60 hectares, an investment of 120 million yuan is required. If the daily waste treatment capacity is 2,000 tons, it can only be used for 11 years. After the expiry, land will be reoccupied and new landfills invested. This will inevitably lead to a sub-cycle of continuous land destruction and continuous investment. 4. The garbage is open for a long time before landfilling. During this period, after fermentation and decay, the garbage breeds mosquitoes, flies and rodents, generates harmful gases and organic waste liquids, spreads diseases, and pollutes the air.

 The second is a classification method. It sorts garbage according to food residues and paper, rubber and plastic chemical fiber waste, glass ceramic mortar, metal, etc., and then uses related processes and equipment to make usable recycled products. For example, food residues and paper are used as compost or organic compound fertilizers, rubber plastic fibers are used to make plastics, glass ceramic lime is used as construction supplies, and metal is recycled into smelting and rolling materials. Adopting this method requires detailed classification of waste, and the pre-processing workload is very large. In fact, it is a sorting process plus multiple specialized factories. In order to reduce the sorting difficulty and workload, it is required to sort the garbage when dumping it. This involves non-technical factors such as social management level and public quality. Since this method can only process the sortable ingredients, there is still no less than 40

% Of the residue can only be taken to landfill in the end. Although this treatment method largely avoids the disadvantages of the landfill method and can recover some resources, it requires high levels of waste sorting and the amount of sorts that can be achieved. In countries and regions with complex waste components, This is not easy. This can not be done well, not only the high running cost, but also the garbage

1

Confirm this The throughput is also small. In addition, the sorting process has a harsh working environment, and workers must wear sanitary protective masks.

 The third is incineration. It is a relatively advanced and mature method of garbage disposal in the world today. After the garbage is concentrated and dried, it is sent to a special combustion furnace, and a certain proportion of fuel (such as fuel oil) is mixed in the furnace and entered into the combustion chamber for combustion. The heat generated during combustion can be used for heating and power generation, and the slag produced can be used as raw materials for building materials such as hollow bricks and concrete after being crushed. The combustion furnace is a very large-scale equipment, including a large-scale conveying mechanism, a drying mechanism, a mixing chamber, a combustion chamber, an air induction system, a slag discharge system, a circulating water system, a heating system, and a power generation system. The advantages of this method are: 1. No need to sort garbage; 2. No residual treatment, and short processing cycle; 3. High resource recovery rate; 4. Less land occupation. However, because the structure of the incinerator is complex and huge, it greatly exceeds the construction of power plants of the same size, so the investment is huge. For example, the construction of an incinerator that can handle 400 tons of garbage per day requires investment of more than 200 million yuan. In addition, a large amount of fuel is required to implement this method. On the other hand, due to high-temperature combustion, chemical substances, especially polymer compounds, in the garbage are cracked, and toxic substances, such as carcinogens, are continuously released into the air. This poses a great threat to human health and has caused serious concern.

Object of the invention

 The object of the present invention is to provide a method capable of completely treating garbage into building material raw materials and organic compound fertilizer raw materials, so that the treatment of garbage does not need to be sorted, is non-toxic, has a large processing volume and is inexpensive.

Content of the invention

 The method for achieving the above objective includes providing waste to be treated less than the volume of the entire brick, placing such waste in a closed device, maintaining it at a temperature of 120-220'C and 3-15 atmospheric pressure for 1-5 hours, and then decompressing To the atmospheric pressure of 0.5-4, the garbage in the airtight device is ejected outward, and the materials that can be made into building materials and organic compound fertilizers that are naturally classified after being ejected are dried, magnetically separated, crushed, and collected.

 According to the method of the present invention, the volume of waste to be treated is provided less than the volume of the entire brick. A vibrating screen and a pulverizer can be provided on the conveyor belt leading to the closed device. A better way is to set the conveyor belt into two layers, and the upper conveyor belt At the end, it is connected to the vibrating screen that is perpendicular to it and tilts downward. The lower end of the vibrating screen is connected to the inlet of the grinder. The outlet of the grinder comes back and connects to the upper conveyor belt. The lower conveyor belt is placed under the vibrating screen at the front end, and the end is closed The inlet of the device is a sieving and crushing circulation mechanism to ensure that the waste to be treated can be continuously provided with a volume smaller than the entire brick volume. If there are no large pieces in the rubbish, they can be sent directly to the closed device.

 The required temperature and pressure in the closed device can be provided by the boiler feeding high-pressure steam, and the pressure can be controlled by conventional methods.

The ingredients that can be used to make organic compound fertilizer in garbage are organic matter such as food residues and paper, In order to separate them and sterilize and deodorize the whole garbage, measures are taken to keep the pressure of the garbage in a closed device for a period of time. The closed device can use a high-pressure pyrolysis kettle. To achieve the effect, the pressure in the kettle The temperature and holding time are better: temperature 120 ~ 220 ° C, atmospheric pressure 3 ~ 15, time 1.5 ~ 5 hours, and even better: temperature 150 ~ 210'C, atmospheric pressure 3 ~ 10, Time is 2 ~ 5 hours.

There should be a dumping area for receiving garbage ejected from the closed device with a size of not less than 800m ² . In order to completely discharge the garbage in the closed device, the pressure difference between the inside and the outside of the device should be maintained until the garbage is completely discharged.

 Because the garbage is sprayed from the closed device with moisture, and it is finally processed into fine particles, in order to facilitate crushing, both types of garbage should eventually be dried at a humidity of 10% to 20%. Drying can be done with electric heat, infrared and hot air. The better way is to use hot air. If the duct of the hot air drying furnace is led to the boiler flue and a heat exchanger is installed on it, the waste heat of the boiler can also be used.

 Magnetic sorting can be performed on a magnetically-conveying conveyor. For example, the conveyor belt is made closed, and it is continuously rotated around the center, so that the lower section is not magnetically permeable, and the other sections are magnetically permeable. When the garbage enters the upper conveyor belt, the iron pieces are sucked. After the garbage reaches the end and falls, the remaining iron pieces enter the lower magnetic section with the conveyor belt, and the iron pieces are sorted out.

 After being dried and magnetically sorted, there are both hard and soft objects, such as ceramics, dust, wood blocks, rubber and plastics, construction waste, glass, etc. as raw materials for building materials, and organic compound fertilizer raw materials. Paper, vegetables, skins, bones, etc., so the equipment used for pulverization is a soft and hard pulverizer. Regarding the garbage that has been separated and will be made into building materials, adjust the internal and external devices of the hard and soft material pulverizer according to the needs of the building materials, and pulverize it into 80-200 mesh size, which will become all kinds of building materials. Garbage that becomes organic compound fertilizer raw materials is pulverized by a soft and hard material pulverizer to a particle size of more than 100 mesh to become organic compound fertilizer raw materials. A small amount of waste that does not contain nutrients, such as plastic and chemical fiber, contained in the organic fertilizer raw materials can only be smashed after being crushed, and can be classified as raw materials for building materials after screening.

In order to form a large-scale garbage processing capability, the main equipments: airtight devices, boilers, drying devices, and hard and soft material grinders can be combined according to different specifications or quantities to form production lines of different scales. For example, 5 8m ³ high-pressure pyrolysis kettles, 4 2 ton boilers, 5 20 kg / min hot-air drying furnaces, and 3 25 kg / min soft and hard material pulverizers can be combined to form 100 tons of waste per day. Production line: Combining 10 10m ³ high-pressure pyrolysis kettles, 4 4-ton boilers, 4 60kg / min hot-air drying furnaces, 10 25kg / min soft and hard material crushers, etc., it can form 300 tons of waste per day. Production line;

Positive effect It can be seen from the above description that the method of the present invention only has low volume requirements for garbage, and does not need to be sorted, and only ordinary equipment is used in the process of disposal, which makes the disposal of garbage much simpler, and sets up production and operation. Both are low-cost and very suitable for countries and regions with complex waste components.

 Because this method allows the rubbish to pass the high temperature (120-220'C) higher than the tolerable temperature for human, animal, and crop pests in a closed state, the fine particles that become the product during or after the treatment are all Sterile and clean (refer to the attached table: 122 types of temperature tolerance table for human, animal, and crop pests); On the other hand, because the temperature does not exceed 220Ό, high-molecular compounds (such as olefins, hydrocarbons, etc.) in the garbage cannot Cracking occurs, so no toxic substances (such as two) are released to pollute the atmosphere.

 Due to the proper temperature and pressure in this method, the long chains of organic molecules such as animals and plants in the garbage that can be used as raw materials for organic compound fertilizers are decomposed into short chains to cause melting, dehydration, and refinement, so that they are compatible with volume, weight, and morphology. Other garbage components form a large disparity, so that a distinct distribution trend after the ejection is bred. It is obtained that more than 80% of the first 15 meters are organic, and more than 90% of the latter 50 meters are almost fan-shaped. The distribution problem solves the classification problem more easily and accurately, and the two types of garbage (except for the rejected metal) can all be made into building material raw materials and organic compound fertilizer raw materials. Therefore, the method of the present invention has almost a 100% resource recovery rate.

 Because the equipment can be combined with multiple configurations, the amount of garbage disposal is large. After the amount of municipal waste rises, adjusting the specifications or quantities of some of the equipment involved in the method can meet a larger amount of waste disposal.

BRIEF DESCRIPTION OF THE DRAWINGS

 Fig. 1 is a schematic diagram of a device according to the present invention.

 Fig. 2 is a block diagram of a process equipment arrangement according to the present invention.

Examples

 On October 20, 1998, small batch production was carried out on the small production line formed according to the method of the present invention.

In Figure 1, 1 is a sieving and crushing circulation mechanism, 2 is a boiler (2 tons), 3 is a high-pressure pyrolysis kettle (2.5m ³ ), 4 is a blanking yard, and 5 is a hot air drying furnace (JBS—LG— RFL). , 6 is a magnetic sorting mechanism, 7 is a hard and soft material pulverizer (LFH-660), 8 is a powder suction machine, 9 is an air compressor, 10 is a heat exchanger, and 11 is a impurity removing screen.

 Process:

At 13:00, dump 20 carts of garbage with a garbage truck for a total of 1 ton. Since there are no large pieces, no screening and coarse crushing are required. They are sent directly to the high-pressure pyrolysis kettle through the elevator. 13:30 After loading, seal the inlet and outlet.

 13:35 Open the intake valve, boost the temperature.

 13:54 The pressure rose to 12 atmospheres and the temperature rose to 210 ° C.

 13: 54-15: 40 The waste in the kettle is pyrolyzed at the above pressure and temperature.

 15:40 Open pressure reducing valve

 15:45 The pressure in the kettle was reduced to 4 atmospheres.

 15: 45-15: 56 The control mechanism is activated, the ejection opening is opened, and the waste in the kettle under the pressure in the kettle forms a fan-shaped distribution area with a length of 80 meters and a width of 15 meters. After identification, a fan-shaped range of 18 meters from the ejection opening Medium is basically a finely divided machine that can be used as raw material for organic compound fertilizers, and the rest is other components in the garbage.

 15: 56-16: 20 Collect all kinds of materials according to the distribution area and send them to the hot air dryer for drying.

 16: 20-16: 30 After drying, the humidity is 10% -15%. After coming out of the furnace, the metal is removed through a magnetic separator and sent to a soft and hard material pulverizer. According to the requirements of the organic compound fertilizer raw materials, the class is pulverized to 120 meshes; 80-120 mesh.

 According to statistics, the total weight of the processed waste is 1 ton. After the high-pressure pyrolysis jet, the total volume of the waste is reduced by 68%. After drying, the weight of the waste is 620 kg, which is a total reduction of 32%. Among them, about 420 kg of waste is used as building materials. About 190 kg of garbage is used as raw material for organic compound fertilizer.

Claims

1. A method for processing garbage into building material raw materials and organic compound fertilizer raw materials, characterized by comprising: providing less than the entire brick volume of waste to be treated, placing such waste in a closed device, at a temperature of 120 ~ 220'C and 3 Hold at -15 atmospheric pressure for 1 to 5 hours, and then decompress to 0.5-4 atmospheric pressure to eject the garbage in the closed device to the outside. After spraying, it can naturally form classified building materials and organic materials that can be produced Compound fertilizers are dried, magnetically separated, crushed, and collected.  2. The method for processing garbage into raw materials for building materials and raw materials for organic compound fertilizers according to claim 1, characterized in that the humidity reached by drying is 10% -20%.  3. The method for processing garbage into building material raw materials and organic compound fertilizer raw materials according to claim 1, characterized in that: the particle size of the waste used as the building material raw material is 80-200 mesh, and the waste used as the organic compound fertilizer raw material is crushed. The particle size is not less than 100 mesh.