Medical Waste High-temperature Steam Sterilization Equipment (horizontal Type)

I. Equipment Introduction

High-temperature steam sterilization (moist heat sterilization) is a type of thermal sterilization. Pathogenic microorganisms, under the influence of high temperature and high humidity, undergo irreversible denaturation and coagulation of proteins and enzymes, leading to their death. This achieves the purpose of killing microorganisms. This high-temperature steam sterilization process for medical waste uses high-temperature saturated steam as the working medium. Utilizing its strong penetrating power, it reaches deep into the interior of the items to be sterilized and releases the latent heat contained within the steam. This rapidly raises the temperature of the items to the sterilization temperature and maintains it for a period of time, causing the proteins in the bacteria to coagulate and denature, thereby killing all microorganisms, including bacterial spores.

II. Sterilization Process

Feeding:

Medical waste is poured into the sterilization carts specially equipped with the sterilizer via a feeding machine. The carts are then transported into the sterilizer. Once the set number of carts in the sterilizer is reached, the front door is closed, and sterilization is awaited. Note: The front and rear doors of the sterilizer cannot be opened simultaneously. Opening or closing the doors is also prohibited once the program is running or if there is pressure inside the sterilizer chamber. This is to ensure personal and equipment safety.

Sterilization treatment:

After the front door is closed, the PLC instructs the sterilizer to begin running the pre-set sterilization program for sterilization. Once the sterilization stage begins, the system automatically times the process to ensure sterilization intensity. During sterilization, the main steam valve and auxiliary steam valve open and close based on the real-time temperature inside the sterilizer. If the temperature inside the sterilizer drops below the set sterilization temperature, the auxiliary steam valve opens to allow steam to enter and raise the temperature. If the temperature inside the sterilizer drops below the set temperature by 1°C (adjustable), the main steam valve opens to allow a large amount of steam to enter and raise the temperature. If the temperature inside the sterilizer exceeds the set sterilization temperature, both the main steam valve and auxiliary steam valve close, ensuring the sterilization temperature while preventing excessive steam waste. After the set sterilization time is reached, the system transitions to the post-vacuum drying stage.

The sterilization parameters are as follows (the purpose of the BD test is to test the air removal effect or vacuum performance to ensure the sterilization effect during normal sterilization):

Output:

After sterilization, the rear door opens automatically, the sterilization cart is pushed out, and then the sterilization cart is transported to the unloading machine basket, which dumps the waste into the crusher for crushing.

Technical advantages:

● The feeding of medical waste is carried out through mechanized and automated operations, reducing direct manual handling.

●The feeding cart also serves as a container for medical waste in the sterilization chamber during the steam treatment process. During the treatment process, the steam penetrates and conducts heat evenly. The material and structure can withstand the temperature and pressure changes during the steam treatment process. 5.1.5 The inner wall is treated with anti-stick coating.

● The feed inlet is airtight and equipped with an air extraction device, and feeding and crushing are carried out under a set negative pressure.

● The layout of the steam nozzles inside the sterilization chamber ensures a uniform temperature field within the sterilization chamber.

● It maintains its normal operating condition within ±10% of the rated voltage.

●The equipment's internal cavity and doors are made of corrosion-resistant materials that can ensure continuous use when in contact with water and water vapor, and are generally made of stainless steel.

● The inlet and outlet doors must meet the sealing performance requirements of the equipment's working pressure; an interlocking device should be installed so that the high-temperature steam treatment equipment cannot be heated or pressurized when the door is not locked, and the door cannot be opened before the end of the steam treatment cycle. The door should be able to be normally open during equipment feeding, discharging, and maintenance.

● The vacuum level in the sterilization chamber should generally not be lower than 0.08 MPa, and the number of cycles of vacuuming and steam charging should not be less than 3; ensure that the air removal rate in the sterilization chamber is not less than 98% after the pulsating vacuum ends.

III. Process Flow

"steam sterilization followed by crushing" as specified in HJ 276-2021 "Technical Specification for Centralized Treatment of Medical Waste with High-Temperature Steam Sterilization" . Specifically, medical waste is loaded into a specially designed sterilization cart and then enters the high-temperature steam treatment unit for sterilization. The sterile medical waste, after high-temperature steam sterilization, is then fed into a crusher for further processing. The crushed waste residue is then sent to a municipal solid waste incineration plant or landfill for final disposal.

Steam treatment followed by crushing process

※1. Medical waste from the turnover boxes is manually loaded into a special sterilization cart. After being emptied, the turnover boxes are manually sent to the turnover box disinfection and cleaning line. After drying, they can be reused.

※2. The sterilization cart filled with medical waste is manually pushed into the high-temperature steam treatment chamber. After the high-temperature steam treatment chamber is full of sterilization carts, the chamber door is closed and interlocked.

※3. Pre-vacuum: The pressure inside the high-temperature steam treatment pot is reduced to -0.09MPa by a vacuum pump. The extracted air is mixed with the high-temperature steam from the boiler for sterilization and then discharged into the condenser for rapid condensation, forming condensate and clean air that are directly discharged.

※4. Steam treatment: High-temperature steam generated by the boiler is introduced into the high-temperature steam treatment pot, raising the temperature inside the pot to 134℃ and the pressure to 0.22MPa. The medical waste inside the pot is sterilized by high-temperature steam treatment. After 45 minutes, the sterilization index specified by the national standard can be achieved.

※5. Post-vacuum treatment: After the high-temperature steam treatment process is completed, a post-vacuum treatment is performed inside the pot to remove the water vapor, dry the medical waste, reduce its temperature, and alleviate its odor.

※6. Condensate is directly discharged into the factory's wastewater treatment pond.

※7. Crushing process: After the pressure inside and outside the sterilizer is equalized, the door is opened, and the sterilization trolley is manually pushed into the elevator and sent to the crusher system to crush and destroy the medical waste until it can no longer be reused, becoming ordinary municipal waste and sent to landfills or waste incineration plants.

※8. Waste gas treatment: Odor gas is collected and discharged using activated carbon filters and integrated treatment processes to ensure that emissions meet standards.