Solutions for the Harmless Treatment of Kitchen WasteDisposalEquipment

1. Process Requirements and Standards:

Process Requirements

(1) The kitchen waste harmless treatment equipment employs high-temperature and high-pressure sterilization technology.  

(2) The treated products can be recycled.  

(3) They can be directly processed and comply with national epidemic prevention regulations.  

(4) The main equipment has a service life of ≥10 years and low maintenance costs.  

Standards  

(1) "Law of the People's Republic of China on the Prevention and Control of Solid Waste Pollution" (2004)  

(2) "Law of the People's Republic of China on the Prevention and Control of Air Pollution"  

(3) "Comprehensive Emission Standards for Air Pollutants" GB16297  

(4) "Emission Standards for Odorous Pollutants" GB14554-93  

(5) "Manufacturing Standards for Pressure Vessels" GB150-2011  

(6) Experience from similar projects and the relevant process parameters used.

2. Processing Technology

Process Description: The collected kitchen waste is lifted to the operating platform by a lift, where staff members dump it onto the sorting platform. An automatic plastic sorting device removes plastic bags, and the waste is then transported to a crusher for processing. After solid material is crushed, it is sent to a screw filter machine to remove free water and grease. Subsequently, it is conveyed to a cooking and drying machine, where it undergoes high-temperature sterilization treatment with a high-temperature circulating heat source introduced into the jacket while being continuously stirred. During this process, the heat source does not come into direct contact with the solid waste. Once the designed process temperature is reached, drying treatment follows. The filtered oil-water mixture undergoes secondary oil-water separation to extract grease. The dried material serves as an ideal raw material for organic fertilizer, while the grease is utilized as industrial oil, achieving harmless treatment and resource utilization. This is currently the most recognized processing method internationally.

Process Parameters:The central temperature of the treated material is ≥100℃; pressure and temperature can be adjusted based on different materials. Vacuum drying lasts 120 minutes, with a complete processing time of about 200 minutes, and the entire processing cycle takes approximately 360 minutes.

Process Characteristics:The method features fast processing speed, thorough sterilization, long equipment lifespan, low processing costs, low labor intensity, high product purity, and no generation of foul odor during the processing.

Process Flow:

1. Collection of Kitchen Waste: Kitchen waste is transported to the processing plant by dedicated vehicles. In principle, it should be processed immediately upon collection. If processing cannot be done timely, it should be stored in a cold storage or temporary area until it can be processed. After unloading, the vehicles are disinfected and cleaned using a disinfection cleaning device.

2. Sorting: The kitchen waste contains items like plastic bags and glass bottles, which are separated at the sorting platform.

3. Material Crushing: The sorted materials drop directly into the crusher's hopper. After being crushed, the particle size of the materials is reduced to ≤40mm for easier subsequent processing.

4. Solid-Liquid Separation: The crushed materials flow into a screw dewatering machine for solid-liquid separation. The separated liquid is transported to an oil-water separator, while the solid materials are sent to a cooking and drying machine.

5. Primary Oil-Water Separation:The liquid material separated by the dewatering machine is allowed to stand in the oil-water separator to layer. Based on the physical phenomenon of immiscibility and different densities, the upper layer oil is extracted and stored in an oil tank, while the lower layer wastewater is sent to the wastewater treatment center.

6. Material Conveying:Crushed materials are conveyed to the cooking and drying machine by a screw conveyor. The spiral mixer inside the cooking and drying machine should be started simultaneously. This entire process is carried out in a closed and automated manner, featuring advantages such as fast speed, minimal residue, easy cleaning, and no foul odors.

7. Cooking and Sterilization: The feed inlet is closed, and heat source is introduced into the jacket of the cooking tank. Once the temperature and pressure in the tank reach the preset values, they are maintained for 30 minutes (in accordance with European and American sterilization standards, adjustments can be made based on different materials regarding pressure and temperature). The spiral mixer is then turned off, and the mixture is allowed to stand for 10 minutes.

8. Secondary Oil-Water Separation:The oil outlet valve of the cooking and drying machine is opened. The upper layer of the oil-water mixture in the tank is transported under high pressure through pipes to a high-positioned oil-water separation tank. After standing for about 10 minutes, the upper layer oil is discharged, filtered, and sent to the oil storage tank, while the lower layer of water material is returned to the cooking and drying machine.

9. Drying:During the drying phase, the high-pressure blower is activated, and hot air is continuously introduced into the jacket of the cooking tank, causing the moisture in the materials to undergo intense vaporization, thereby reducing drying time and improving product quality.

10. Discharge:The dried materials are conveyed by a screw feeder to an air cooler. After cooling, they are sent to an automatic packing machine for automatic quantitative packaging and storage.

3. Equipment Design Principles:

Safety: Strictly adhere to national standards (GB150-2011 <Standards for Pressure Vessel Manufacturing>).  

Energy Efficiency: Optimized pipeline design, rational use of temperature, pressure, and time for energy saving and efficiency.  

Advancement: Introduce Danish harmless treatment technology to achieve the goal of harmless treatment and resource utilization of kitchen waste.  

Environmental Protection: Closed processing, gas recovery, multi-stage treatment; minimal wastewater, free of pathogens, and easy to handle.  

Automation: Computer PLC with touch screen control, full monitoring, and automated control.