Solution to common problems in purifying air conditioning systems in pharmaceutical factories
1, system selection
Purifying the air conditioning system is the key equipment to ensure the production environment of the drug. In actual operation, the pre-air conditioning system is unreasonable, resulting in the risk of cross-contamination in the production of drugs, large fluctuations in room temperature and humidity, difficulty in system adjustment, high energy consumption, high cost of modification and maintenance, and the production environment of the drug cannot be Meet the requirements of pharmaceutical production management regulations, and bring drug quality risks. Therefore, when purifying the design of the air conditioning system, the above situation should be fully considered and similar situations should be reduced and avoided.
The basic basis and principle for the division of air-conditioning purification systems for pharmaceutical production enterprises are:
1 Divided by product category to avoid the risk of cross-contamination.
2 According to the different production environment (cleanliness level), rooms with different cleanliness levels should be divided into different air conditioning systems for control.
3 According to the indoor temperature and humidity base (such as 18 ~ 26 ° C, 45% ~ 60%) and accuracy (such as ± 0.5 ° C, ± 5%) to divide the air conditioning system.
4 According to the space (room orientation, floor) position, etc., the air conditioning system is divided to facilitate the layout and installation of the air duct, which is conducive to the later operation management.
5 According to the hazards of toxic and hazardous substances and dust concentration, the air conditioning system is divided to avoid cross-contamination and improve the life of medium and high efficiency filters.
6 According to the air-conditioning running time and the usage of the shift, the air-conditioning system is divided to facilitate the economical operation.
7The air conditioning system is divided according to the flow pattern (layer flow, turbulent flow) of the room.
The humidity and heat load of the 8 rooms vary greatly, and the room where the temperature and humidity in the area needs to be strictly controlled should be partitioned, or set up with local processing equipment (reheat system, partition unit system, etc.).
9 For the convenience of operation and maintenance, the large air volume air conditioning system should be divided into different small systems according to the actual situation, generally with a flow of ≤40000m3/h.
10 According to the requirements of the fire compartment, the partition of the air conditioning system should meet the requirements of the fire compartment of the building.
2, air volume selection
In addition to meeting the requirements of clean room temperature and humidity, and preventing the outside air from polluting the indoor cleanliness, the air supply system of the air conditioning system needs to replace and dilute the indoor air pollutants, maintain the cleanliness level of the environment, and ensure a reasonable airflow direction. . In the actual operation of the air conditioning system, there is a lack of room air volume resulting in poor cleanliness, and the room air volume is too high, resulting in increased energy consumption, resulting in difficulty in balancing the air volume during system commissioning and poor system stability during operation. Therefore, when selecting and purchasing the air conditioning unit system, the air supply volume of the air conditioning system fan should be reasonably considered; the system should regularly monitor the change of air volume during normal operation to prevent the air supply volume from affecting the cleanliness of the clean room.
3, air conditioning fan selection points
(1) The total air supply volume of the fan should meet the required air volume for the minimum number of air changes in each room (the number of volume flow changes in the room within 1 hour). The total air supply is usually estimated based on the cleanliness level of the room and typical values ​​of engineering experience rules: FDA and ISPE's CNC (EU D-class dynamic standard) level space, 6-20 times/h; ISO8 level (EU C-level dynamic standard) Space, 20~40 times/h; ISO7 level (EU B-level dynamic standard) space, 40~60 times/h; ISO5 level (EU A level) space, for unidirectional flow, there is no relationship between ventilation times Airflow speed and form are critical.
(2) Considering the minimum amount of air required to remove the humid heat source from the room.
It usually includes the following situations:
1 The amount of air required to remove the increase in heat generated by room equipment and personnel activities.
2 The amount of air required for the increase in damp heat generated by the cleaning activity.
3 Different air volumes required due to differences in air supply mode and efficiency.
4 The operator's dress (clean clothes or gowns) differs in the amount of air required.
5 The process flow and its particle generation rate are different, resulting in more power demand for the power unit.
The different air volumes required for the 6-room exhaust mode and location.
(3) In order to achieve the required air volume required for the differential pressure, this value is usually less than the requirements of (1) and (2).
(4) Try to choose the direct connection mode of the fan to reduce the belt maintenance; use the fan inverter to save energy and economy.
4. Common situations and treatment methods for reducing air supply volume
(1) Fan belt wear and slip causes the fan output to decrease; replace the worn belt and tighten the belt tension.
(2) The soft connection between the air duct and the static pressure box is damaged and leaks; repair and replace the soft connection.
(3) Air leakage at the interface of the air supply pipe; glass glue seals or reconnects the air leakage seal.
(4) The primary and intermediate-effect air filters are clogged, and the air supply volume is insufficient; the differential pressure before and after the filter is monitored, and the filter is replaced in time.
(5) The high-efficiency filter is clogged and the wind cannot be sent out; the air volume and pressure difference of the tuyere are regularly detected, and a reasonable replacement period is determined according to the use condition.
(6) The system returns air, the exhaust filter is clogged, the room wind pressure is large, the wind does not go out; the filter is cleaned and replaced regularly.
(7) The position of the air supply valve changes during operation, which causes the valve to close and cannot supply air. After the air volume is adjusted, lock and fix the valve opening degree, affix the position mark and regularly inspect.
5, pollutant control
Depending on the process and properties of the drug, the drug needs to be produced in different clean levels. Relevant drug production and management regulations at home and abroad, in their respective drug production quality management documents, specify the number of airborne particles in the production environment of drugs. The factors affecting the cleanliness of the clean room consist of two parts: exogenous and endogenous. Exogenous contaminants include the introduction of clean room air and the infiltration of contaminants from the clean room enclosure. Endogenous pollutants include dust from workers, dust production during production of equipment and products. Controlling dust particle pollution is an important function of purifying air conditioning systems to ensure the purity, uniformity and quality of drugs. Inadequate maintenance and management of the air-conditioning system will lead to production stoppages and drug scrapping, which should cause sufficient attention of the air-conditioning system maintenance and management personnel.
The control measures for clean room contaminants are as follows:
1 The air conditioning primary and medium efficiency filters should be cleaned or replaced regularly, and the chassis or air supply ducts should be cleaned regularly.
2 High-efficiency filter periodic leak rate detection, air volume reduction or damage replacement in time.
3 The doors and windows of the clean room, the gap between the wall, the ground and the ceiling should be sealed, and the connection between the inlet and outlet of the clean room should be sealed to prevent the source of external pollution from entering the clean room.
4 Clean room personnel wear suitable dust-free overalls, standardize operations, and reduce unnecessary movements.
5 Reduce the dust production of indoor materials, and choose the closed production process and equipment.
6 Materials and articles entering the clean room should be cleaned, using materials that are not easy to generate dust, and reducing unnecessary moving routes.
7 Regularly clean all kinds of equipment and facilities in the clean room to prevent the generation and retention of pollutants.
6, differential pressure control
The pressure difference in the clean room is to maintain a certain static pressure difference between rooms with different cleanliness levels or between different clean rooms of the same level. The purpose is to protect the cleanliness of the clean room during normal work or temporary damage to the air balance. The pollution of the adjacent room is also clearly defined in the domestic and foreign drug production regulations, so the differential pressure control is a very important link in the purification of the air conditioning system. In the operation of purifying air-conditioning systems in pharmaceutical companies, cleanrooms often experience excessive or low pressure differentials, large fluctuations, and even reverse airflows, which poses a quality risk of pharmaceutical production.
According to empirical analysis, the main influencing factors of the pressure difference in the clean room are that the management and maintenance are not in place, and the system design is unreasonable. The capital investment is insufficient, resulting in poor pressure difference stability of the clean air conditioning system. It is necessary to frequently adjust the fan parameters and supply air. Return air, exhaust valve.
The factors affecting the pressure difference in the clean room and the countermeasures are as follows:
(1) Purifying the change of the air filter resistance of the air conditioning system, causing a change in the amount of air supply, thereby causing a change in the pressure difference in the room. The primary, middle and high-efficiency filters can be replaced regularly; or the inverter blower can be used to control the fan speed with the difference between the actual air supply volume and the set air supply volume to ensure a constant air supply.
(2) The opening and closing of the clean room door will cause fluctuations in the pressure difference of the clean room. Reduce the number of opening and closing of the door and close the door; set the buffer chamber or air lock; install the residual pressure valve, change the opening of the residual pressure valve by balancing the pressure block, and realize the control of the differential pressure of the clean room.
(3) The indoor pressure is detected by the differential pressure transmitter, and the opening degree of the air supply or return air valve is controlled to realize the control of the differential pressure of the clean room.
(4) The air leakage in the gap between the door and window of the room is too large, causing the pressure difference to be too low. The sealing structure and the sealing strip of the door can be regularly checked to ensure good air tightness.
7, temperature, relative humidity control
In the clean room, if the temperature is too low, it is not easy to work normally; while the temperature is too high, the sweating of the personnel increases the pollution of the clean room; while the temperature, relative humidity sensitive materials, temperature and relative humidity need to be strictly controlled, otherwise the product Quality cannot be guaranteed. Therefore, ensuring that the clean room temperature and relative humidity meet the process requirements is an important capability of the air conditioning system. There are usually a number of factors that cause the clean room air temperature and relative humidity to not meet the requirements, and different countermeasures should be taken.
(1) Some pharmaceutical plants have many and large heating equipment. If only the number of air changes is determined, it will often lead to excessive temperature in the clean room. For example, through the fan filter unit (FFU) to achieve the Class A purification zone, the air conditioning unit needs to be separately configured or the secondary air cooling (heating) mode of the air supply branch pipe is used to control the room temperature.
(2) There are problems in the design, installation and commissioning of chilled water pipelines. When multiple air conditioning units are used in parallel, the flow distribution is uneven when chilled water is used. The temperature and humidity control of air conditioning units is difficult. Pipeline transformation or water balance adjustment should be carried out.
(3) The equipment maintenance is not in place, resulting in temperature and relative humidity out of range when the air conditioning system is cleaned. For example, surface cooler fouling, fin dust accumulation leads to low heat exchange efficiency, pipeline clogging leads to insufficient water flow, chilled water supply water temperature is too high, steam supply pressure is insufficient, steam condensate is not hydrophobic, and maintenance should be strengthened. Management and implementation.
8, purification air conditioning unit design
The air-conditioning unit is a device that realizes functions such as cooling, heating, dehumidification, humidification, purification, etc. through air purification and heat-moisture treatment. The design and improper selection will greatly plague the use of the purification air-conditioning system. When selecting and confirming the air conditioning unit, it is necessary to pay attention to possible problems and reduce the troubles in later debugging and operation.
(1) Insufficient maintenance space. For example, the distance between the sides of the air cooler and the sides of the heater is insufficient, and the heat exchanger maintenance situation occurs, and the cabinet and related components need to be removed to be repaired.
(2) The functional section spacing is insufficient and no other remedial measures are taken. For example, the distance between the fan air supply section and the medium efficiency filter section is short, and the flow plate is not installed, resulting in the air filter speed of the entire section of the medium efficiency filter at the fan outlet. Extremely uneven, affecting the filtration effect and shortening the service life of the filter.
(3) The wind speed on the windward side of the box is relatively large, causing the condensate pan to float after the cold section. If the design of the water deflector is unreasonable, the problem is more serious. Therefore, when selecting the type, the wind speed on the windward side of the air cooler should be controlled as much as 2~2.5m/s.
(4) The overall sealing performance of the unit is poor. If the power cable of the air conditioning unit passes through the chassis, the connection with the chassis board is not tightly sealed or even processed. Therefore, the quality of the unit is strictly checked and accepted. Usually, the standard requirement of the "combined air conditioning unit" [4] is that when the static pressure of the air-conditioned box is 1000 Pa, the air leakage rate inside the machine must not exceed 2%.
(5) The design of the condensate system of the unit is unreasonable. The water trap cannot store water or the condensed water cannot be discharged from the tank. It affects the inner surface of the air conditioning unit and affects the life of the filter. It also affects the heat and humidity treatment. Generally, the height of the condensate pan is greater than 50% of the negative static pressure (water column height) of the unit, the slope of the condensate pipe is ≥0.3%, the height of the trap water seal is 2 times the maximum negative static pressure of the unit, and the total height of the trap is about the maximum of the unit. Negative static pressure 4 times.
(6) The design of the water outlet of the air cooler is unreasonable, and the water storage cannot be discharged cleanly, which causes the surface cooler to freeze and crack, which is difficult to maintain and replace. It is recommended that when the air conditioning unit is used in the north, when the use of the chilled water is stopped, the cold water supply and exhaust pipe is disconnected, and the air cooler is used to blow off the water in the air cooler; if some chilled water is still present, it can be charged in the air cooler. Pack an appropriate amount of ethylene glycol solution to prevent freezing.
9, energy-saving operation management
In pharmaceutical manufacturing enterprises, the energy consumed by the purification of air-conditioning systems accounts for about 20% to 30% of the energy consumption of the entire enterprise. This shows that air-conditioning energy conservation is a very important task. Since the daily management and maintenance of air conditioners are not in place, there are many hidden phenomena of air-conditioning energy. From the perspective of improving business performance, it is of great practical significance to realize energy-saving operation of air conditioners. The energy consumption of the HVAC system mainly depends on the determination of the air conditioning cold and heat load and the reasonable operating parameter configuration of the air conditioning system. Through good operation and maintenance management, the energy consumption of the air conditioning system can be completely reduced.
(1) Since the air supply volume and pressure loss of the air-conditioning fan change with the increase of the resistance of the primary, middle and high-efficiency filters, in order to maintain the cleanliness of the room, the air volume of fresh air, air supply and return air needs to be consistent, so The air-conditioning system is equipped with an inverter fan. By changing the fan frequency and changing the air volume to achieve the requirements of purification and air supply, the energy-saving requirements can be achieved.
(2) Before the operation, the air conditioning system should be subjected to pressure test, cleaning and descaling to prevent heat exchange efficiency and increase operating costs.
(3) Regularly replace the primary and secondary efficiency filters of the air conditioning system to reduce the waste of power from the fan.
(4) Increase the use of outdoor fresh air during the transition season to adjust indoor temperature and humidity.
(5) Under the premise of meeting the temperature and humidity requirements of the clean area, appropriately increase the (summer) or lower (winter) temperature and humidity control values.
pet bird toys,pet mouse toys,interactive pet toys,pet bunny toys
Ningbo XISXI E-commerce Co., Ltd , https://www.petspetscare.com