The cleanroom system has become one of the plans for a new food baking factory, but it is not enough to just have a cleanroom to put everything at ease. The cleanroom system only allows the production process to be carried out in a good environment. Factors that affect the shelf life of food include contact contamination by employees during operation, cross contamination between raw materials, and the rationality of formulas.

1、 Working principle of purification system in food dust-free workshop:

Airflow → Primary air treatment → Air conditioning → Medium efficiency air treatment → Fan air supply → Purification pipeline → Air supply outlet → Clean room → Removal of dust particles (dust, * *, etc.) → Return air duct → Processed airflow → Fresh air airflow → Primary air treatment. Repeat the above process to achieve the purification goal.

2、 Cleanliness requirements for food dust-free workshops

According to the national regulations on the review of food production licenses, it is recommended that the cleanliness level of the food baking workshop reach 100000 (300000 is no longer sufficient for the current trend of shorter food shelf lives), and individual areas can be adjusted according to requirements.

Cleanliness standard for 100000 level cleanroom

1. Allowable number of dust particles per cubic meter.

2. The number of particles larger than or equal to 0.5 microns shall not exceed 3500000, and the number of particles larger than or equal to 5 microns shall not exceed 20000. Instrument: Dust Particle Counter

3. Maximum allowable number of microorganisms.

4. The number of planktonic bacteria shall not exceed 500 per cubic meter. Instrument: Floating bacteria sampler

5. The number of sinking bacteria should not exceed 10 per culture dish.

6. Pressure difference: The pressure difference between cleanrooms of the same cleanliness level should be consistent. For adjacent cleanrooms of different cleanliness levels, the pressure difference should be ≥ 5Pa, and between cleanrooms and non cleanrooms, it should be ≥ 10Pa. Instrument: Differential pressure gauge

7. Temperature and humidity requirements: When there are no special requirements for temperature and humidity in a 100000 level clean room, it is advisable to wear clean work clothes that do not produce a comfortable feeling. The temperature is generally controlled at 20-22 ℃ in winter; Summer temperature ranges from 24 to 26 ℃; Fluctuations of ± 2 ℃. The humidity in the clean room should be controlled at 30-50% in winter and 50-70% in summer. Instrument: Temperature and Humidity Meter

8. Distribution: The general illumination value of the main production rooms in the clean room (area) should be ≥ 300Lx; the illumination value of auxiliary workshops, personnel purification and material purification rooms, airlock rooms, corridors, etc. should be 200-300Lx. Instrument: Illuminometer

3、 Layout plan of food dust-free workshop building:

The layout of the building should belong to the category of architecture, but due to the requirement of separating people and materials in the food purification workshop and maintaining a static pressure gradient in each clean operation room, the building layout in this project requires the following points:

1. Each purification operation room is equipped with an independent front room as an airlock, which is connected to each operation room at the same time to ensure that the air in the low cleanliness area does not penetrate into the high cleanliness area.

2. The flow of people in the laboratory passes through the changing room, changing clothes and shoes, washing hands in the cleaning room, buffer room, air shower room, and various operating rooms.

3. The logistics of the food air purification workshop enters the buffer corridor through the mechanical chain transfer window from the outer corridor, and then enters each operating room through the transfer window.

4、 Structural system of food cleanroom:

According to the "Code for Design of Cleanroom", the walls and ceilings of the workshop must be constructed with materials that do not produce dust, have a smooth surface that does not accumulate dust, and there should be no corners in the workshop. We use clean factory construction color plates, and the substrate top plate is made of Baosteel 0.4 steel plate with a core material density of 14kg/m3. The aluminum material is made of Hualian aluminum profiles. In order to improve the service life of the purification room and achieve a beautiful and elegant effect, all aluminum profiles are subjected to electrophoretic treatment.

5、 Ground system of food purification workshop:

The ground is made of solvent based epoxy resin, with a strength of C20 or above, a dense surface, and no sanding, hollowing, or cracks. Colorful, with long-lasting anti-static performance, able to withstand medium to low loads, and resistant to high temperatures. On the basis of meeting the requirements for use, it can serve as a decorative element, with wear resistance, washability, dust resistance, slip resistance, performance, uniform color and luster.

6、 Food cleanroom lighting system:

Ceiling mounted purification lamps should be used in clean areas, while ordinary fluorescent lamps should be used in non clean areas. Design lighting in each room, with independent control of ultraviolet lamps, all controlled by electrical control boxes, and then centrally controlled by the main distribution cabinet. Indoor lighting adopts enclosed lighting fixtures. The socket plates are all embedded. There is no visible wiring indoors.

1. The food industry has clear regulations on the flow of personnel and materials, and cross flow is not allowed. Material transfer ports or gates need to be set up for material flow. The personnel channel required for personnel flow.

2. According to the production process, hygiene, and quality requirements, classify cleanliness and specific requirements.

7、 Purification equipment that should be equipped in food purification workshops:

Purification products such as air filters, air shower rooms, clean workbenches, clean laminar flow hoods, filter air outlets, air purifiers, ozone generators, stainless steel clean doors and windows, dehumidifiers, fume hoods, etc.

8、 Selection of Decoration Materials for Food Cleanroom:

1. Cleanroom walls and ceiling panels are generally made of 50mm thick color steel plates;

2. Epoxy self leveling flooring or wear-resistant plastic flooring can be used for the ground. For those with anti-static requirements, anti-static types can be selected;

3. The return air duct is made of hot-dip galvanized sheet and coated with flame-retardant PF foam plastic sheet with good purification and insulation effect;

4. The air supply outlet should be made of stainless steel frame, which is aesthetically pleasing and clean. The perforated mesh plate should be made of painted aluminum plate, which is rust free and dust-free. It is suitable for cleaning industrial cleanrooms: according to the US federal standards, a cleanroom means that "the number of dust particles in the air in the room, as well as the temperature, humidity, and pressure if necessary, can be controlled". The main purpose of a cleanroom is to control dust.

The above is a summary of how to carry out purification engineering and precautions in food dust-free workshops.