Table. 2. The optimal selection of filters used in Switzerland for classes of clean rooms according to ISO 14644-1 (GOST R ISO 14644-1)
By now, engineering practice has been developed typical decisions, following which avoids inaccuracies and do without unnecessary capital and operating costs. These typical solutions refer to:
The experience of the laboratory of tests of clean premises of the company Invar in the certification of projects (DQ stage) and built clean rooms (Stages IQ, OQ and PQ) revealed characteristic errors.
Initial data when designing the ventilation and air conditioning system
Before the start of the design, it is necessary to clearly formulate its purpose and determine the source data. Errors and inaccuracies at this stage will lead to improper performance of all work. These source data include:
Structure of ventilation and air conditioning systems
Multiple types of air flows participate in the ventilation and air conditioning system:
It should also be taken into account air leaks from high-pressure premises (air exhaustration, l e) and air infiltration into the room with reduced pressure, L and. Simple scheme The ventilation and air conditioning is the direct-flow system when 100% of the outer air is supplied to the room (Fig. 1). This system is uneconomical, since the entire air entering the air passes a full preparation cycle - on the parameters of the outer air to the required air parameters of the clean room. This system is characterized by high energy costs and a reduced filter service life.
where I is the room number. To a certain extent, improving the indicators of this system allows heat recovery (Fig. 2). Due to the recovery, energy savings are achieved to heat up to 60%.
L n \u003d l n p \u003d σl pi \u003d σl vi \u003d σl vi + l e, l y \u003d σl Вi,
where I is the room number. Direction systems, due to their non-economic, are applied only where they are necessary and where air recirculation is unacceptable (work with harmful substances, dangerous pathogenic microorganisms), ch. 17. Where possible, systems with recirculation are used, which allows to reduce energy consumption several times compared with direct-flow systems. An example of a single-level system with recycling is shown in Fig. 3.
L B \u003d ΣL VI, L U2 \u003d ΣL VMI,
L p \u003d l n + l p \u003d σl pk, l y \u003d l y1 + l y2 \u003d l in - l p + l y2 \u003d σl vi - l p - σl vmi, l p \u003d l in - L u1,
where L VMI is the air flow rate of the local retracting installation from the I-th room; L BI - air flow supplied to the air conditioner from the I-th room. In conditions cold winter Or hot summer, as well as when servicing clean rooms, a two-level system is used by several air conditioners. In it, the outer air is prepared to certain parameters in a separate (central) air conditioner, and then fed to recirculation air conditioners (Fig. 4).
Local filter fencing or recycling installations (Fig. 5) are widely used to create zones with a unidirectional air flow, for example, in operating and other critical zones. The schemes cited give a general approach to the design of ventilation and air conditioning systems, they do not cover the entire variety of options for principal solutions, which in each case should be developed on the basis of the task in the smallest capital and operating costs.
The above types of air flows should be determined for each room and the system as a whole. On this basis, the balance of air exchange is calculated, the results of which are made in the form of a table and are applied to a fundamental scheme of ventilation and air conditioning (Fig. 6). To regulate the balance of the air exchange, it is advisable to install valves on the influx and exhaust.
The meaning of the construction of the air exchange balance is to check that the total air flow entered into the room should be equal to the total air volume removed from the room. Violation of this condition leads to the impossibility of providing the required pressure drops, the difficulties of opening and closing doors, etc. For clean rooms, it plays a special role, since it is necessary to maintain various pressure in different rooms.
In the airbag balance table, the total consumption of supply air and the total consumption of the air removed must be equal to each room (for each line of the table). For each clean room, there is a calculation and exhaust air, and air leaks are taken into account (exhaustration - air leakage into rooms with lower pressure, air infiltration - air intake from the room with more high pressure). The main source data for the development of the project of the ventilation and air system of clean rooms:
The external air consumption is calculated from the need:
Exterior air consumption for the entire ventilation system is equal to the amount of air costs for each room. Air flow for a separate room is equal to the sum of air volumes removed by local exhaust installations, and losses due to leaks. This amount should not be less than the minimum external air flow on regulatory documents.
Calculation of supply air for each room
Passion air performs the following functions:
The required multiplicity of air exchange is affected by all the functions of the air intake air. For each of them, the necessary multiplicity of air exchange is determined and the highest value is laid in the project. Consider each of the listed functions.
Class of purity
It is ensured due to the multistage filtering of air and select filters of the corresponding classes, the speed of air flow (for a unidirectional air flow), the multiple of the air exchange.
Multiplicity of air exchange
Specifies air flow for clean rooms of classes 6-9 ISO (Zone B, C, D). For zone, air flow is determined by the speed of the unidirectional flow. There are several approaches to the definition of the multiplicity of air exchange to ensure purity:
Removal of excess heat and moisture
Technological equipment and staff allocate heat and moisture to be removed using the ventilation and air conditioning system. Ensuring the necessary microclimate with the maintenance of temperature and humidity is an important condition for ensuring the normal operation of personnel in clean rooms. In addition, individual technological processes (for example, photolithography in the production of microcircuits) provide strict requirements for temperature and humidity.
Compensation of exhaust installations
The total volume of exhaust air for this room is determined. Private from dividing it on the size of the room gives the multiplicity of the air exchange required to compensate for hoods.
Compensation of leaks
Pressure drop between different rooms It causes the exhaustion (leakage) of air from the room through the slots in the doors of the doors and a different kind of looseness. The leakage must be calculated for each room and is taken into account in the air exchange balance. Air leakage must be compensated with an equal number of outdoor air in the supplied air. In the balance of the air exchange must be taken into account and infiltration of air, i.e. Air flow from adjacent premises.
Multiplicity of air exchange in general premises
In such premises, the calculation of the multiplicity of air exchange is carried out in accordance with the sanitary standards and according to the calculations of excess heat and moisture. In Western countries, the following datasets of air exchange (data from Airflow, England) are used for some premises (Table 1).
Selection of filter types
Usually, air preparation systems for clean rooms are performed by three-stage:
In addition, the use three-stage system Air filtration guarantees a long service life for HEPA and ULPA filters. Recommendations on the optimal selection of filters are presented in Table. 2.
Characteristic errors
Classes of purity
The most common misconception is the requirement of the production of non-sterile drugs in clean rooms. It is generated by the notorious and illiterate ease of 42-510-98 and the documents previously prior to it. Nowhere in the world there is no requirement to produce non-sterile forms in clean rooms! The only document containing specific data on the purity of the supply air in the production of solid forms is the leadership of the International Organization of the Pharmaceutical Industry Engineers (ISPE).
It contains recommendations on the effectiveness of finishing filters for various stages of the technological process. In world practice, these recommendations are used broadly without specifying cleanliness classes. No one prohibits the use of clean rooms, and many specify the production of solid forms in Z zones, and liquid non-sterile forms - in the zones of C. But what way to choose - apply clean rooms or simply limit oneself to a certain level of cleanliness of the supply air and the quality of the enclosing design - the case customer.
This logic follows the GMP EU (GOST R 52249) and US manuals. If someone wants to tear the company to apply the optional cleanliness class, then we recommend simple and effective tool: Legically, to make this coercion so that the initiator is carried out for it. No arguments (in the wrong "so make our" advanced "neighbors") should not be taken into account.
Widespread and overstate the classes of purity in sterile production. It should be borne in mind another factor. Other project organizations Artificially overestimates the classes of cleanliness and sizes of clean zones. The cost of the project and the perpetrators fee directly depend on the classes of cleanliness and costs. In practice, the author met a project, in which the selection of particles by the staff was overestimated 100 times!
Unreasonably strict requirements for temperature and humidity
For example, the requirements are found to maintain air temperature of 22 ° C with an accuracy of ± 1 ° C and moisture within 45-50% without justifying the process. A simple expansion of the limits of adjusting the parameters of the microclimate within the existing norms makes it possible to significantly simplify the entire system.
Unnecessary use of forwarding systems
Previously, in the conditions of the costly mechanism of public financing, direct-flow systems were widely used, even where they were not needed. In world practice, air recirculation is used everywhere, where it is permissible in terms of security. Otherwise, recycling in winter heats out the outer air, and in the summer it cools, i.e. Significant costs fly literally into the pipe.
Owning the speed of air exchange Wrong selection of filters
The projects often include low filter classes (for example, G3) on the first stage of filtration. This increases the dust load on the filters of subsequent steps and reduces their service life.
Absence concept and air exchange balance tables
Without them, it is impossible to judge the project. Their development is obligatory. These errors are characteristic examples and do not exhaust the entire list of shortcomings.
Without clean rooms, it is impossible to present the production of electron microcircuits, pharmaceutical industry, effective treatment of patients, conducting research in various sectors of medicine and cooking. Pure is considered a room in which the number of aerosol particles and the number of bacteria in the air is supported by a permissible level. There are nine classes of clean rooms depending on the concentration of dust and bacteria in the air. They are fixed in GOST ISO 14644-1-2000, which is based on the international standard ISO 14644-1-99 "Clean premises and related environments".
As part of the usual air (which we breathe in everyday life) is a large number of impurities (I was able, dust, pollen flower, viruses, fungi). The listed impurities are unacceptable for clean rooms, as they adversely affect the work. Therefore, the creation of ventilation and air conditioning systems in clean rooms is a mandatory component of the suitable microclimate.
Designing and installation of ventilation and air conditioning systems requires skills in working with special equipment, as well as knowledge of the norms and requirements for clean premises.
There are three schemes for organizing air exchange in clean rooms:
Depending on the size of the room and the location of the working area, the optimal project of the ventilation system is chosen, but the most optimal solution is ventilation with a unidirectional flow of clean air.
For clean rooms, an exclusively impressive ventilation system and air conditioning is used. Its essence is as follows: a flow of clean air, which "squeezes" contaminated air, which is indoors, is amenable to top under pressure at a certain speed.
The cooled air is amenable to low speed, as a rule, into the upper part of the room (about 1/4 of the room) through the ceiling panels. It seems to be strengthened by space, lowering dust down, to the exhaust, and the minimum level of irritation is created. With such ventilation there are no drafts, whirlwinds of dust that have seen on the floor. In addition, the air supplied is pre-prepared to the desired temperature and humidity.
The basis of the ventilation and air conditioning system is supply-exhaust installation With recycling consisting of the following elements:
General scheme of the system of ventilation of clean rooms.
Special requirements are presented to filters. The filtration system consists of three groups of filters through which the air flow passes:
Coarse and fine filters are located in the central air conditioner, and the HEPA and ULPA filters are directly in the air distributors.
Hepa and ULPA filters
Depending on the size of the room, air pressure, the method of placing furniture is determined by the number and characteristics of air intakes and air distributors.
There are a number of rules that need to be taken into account during the design of exhaust ventilation of clean rooms:
Below are the most optimal systems for ventilation and air conditioning clean rooms.
A) A unidirectional flow is amenable to a ventilation grid.
B) Air is amenable to different sides due to diffusers located on the ceiling.
C) Unidirectional flow enters the room due to the perforated panel on the ceiling.
D) Air is supplied directly to the working area through the air distributor, located on the ceiling.
E) Clean air flow moves in opposite directions due to the equipment of ring air hoses.
Such requirements are presented to ventilation systems for clean rooms:
In addition, the system of ventilation of clean rooms is directed to "blocking" the appearance of such effects:
The air exchange in the room is determined through air mobility, which is measured in m / s. Only for sterile premises in the pharmaceutical industry consolidated a clear definition of the necessary air exchange - 0.46 m / s ± 0.1 m / s (FDA, USA). Recommended air mobility standards for clean rooms range from 0.35 to 0.52 m / s ± 20%.
Also, the air exchange is affected by the availability of windows. So, in a hermetic room without windows, air performance should be 20% higher than the exhaust, and in the room with windows - by 20%.
Pure room (Clea NR OOM) is a room in which the concentration of suspended particles weighted in the air, built and used so as to minimize the receipt, isolation and hold of particles indoors, and allowing, as needed to control other parameters, for example, temperature, humidity. and pressure.
In such premises, the content pollutants in the air, on the surfaces of the walls and ceiling must be supported at a minimum level.
Specified particles There may be materials such as dust, exhaust gases for anesthesia, as well as microorganisms.
Extremely clean indoor air can be achieved only when the inner air is removed and the filtered outstanding air conditioned air.
In addition, as well as in the classical system, the parameters of comfortable conditions should be monitored, such as temperature, relative humidity, noise level, pressure and air speed, as well as the minimum exterior consumption.
Clean premises technology serves the following tasks:
Clean room involves the presence of a clean atmosphere , pure gas, clean surfaces, clean equipment, pure products and clean technology.
No projects and investments should be performed before determining hygienic requirements To clean room.
It is necessary to ensure guaranteed hygienic quality and maintain the necessary degree of air purity indoors (not necessarily as possible).
High hygienic quality can be provided with the realization of an expensive project of protection.
The main approach should provide for the satisfaction of hygienic requirements, where necessary, the most inexpensive methods and with maximum efficiency, but only to the extent that it is necessary for a particular room.
Parameters affecting implementation required conditionscan be divided into two groups: support parameters comfort and hygiene.
The criteria for comfortable air parameters are:
These parameters are important for the assimilation of heat dissipation from external and internal sources, as well as to compensate for heat loss and to ensure comfortable conditions in the room.
Criteria of hygienic air parameters:
The parameters of maintaining hygienic conditions are the concentration of microbes and polluting gases, as well as air movement between the rooms.
In this regard, the concentration of pollutants should be at the minimum required level, the air movement between the premises must be monitored.
but during the design, these parameters should be considered in their totality . For the assimilation of insulating insulation, providing the necessary air quality, the amount of air-conditioned air should be checked, as well as the amount of displacing air necessary to maintain the concentration of microorganisms in the room below a certain level.
Clean rooms are used in areas such as medicine, microelectronics, micromechanics and food industries.
In medicine, operational, premises for the preparation of drugs, biochemical and genetic laboratories are purified from solid particles and microorganisms.
Clean rooms are used in microelectronics, cosmic technology, thin-film technology, the production industry industry and in the adjacent directions of these areas, where the removal of polluting particles is necessary.
In the food industry from production premises Remove both particles of pollutants and microorganisms.
Clean room with turbulent air flow
Live microorganisms.Bacteria, fungi and viruses fall into this category. Microorganisms can develop in the form of colonies in air, water and especially in cracks and on rough surfaces. The most common source of microorganisms is the human body that distributes about 1,000 types of bacteria and fungi.
Pollutants other than microorganisms. Weighted in the atmosphere of substances and substances other than microorganisms are present in the atmosphere as a result of windquarters, earthquakes and volcanic activities. These are usually called dust or aerosol. This group includes particles of smoke, which is the result of industrial processes, systems for the heating of buildings and emissions of car exhaust gases. In the same group also includes suspended particles, the sources of which are moving parts of machines in clean rooms. In addition, as a result of the actions of people in a clean room in the air of this room, about 100,000 particles of less than 3 microns are falling.
Sterility. So it is possible to characterize the situation in the room at which there are no microorganisms in products and devices.
Sterilization. Technique of destruction or destruction of microorganisms in products or devices.
HIGH EFFICIENCY PARTICULATE AIR FILTER is a highly efficient aerosol filter). Such filters are a variety of highly efficient air filters. They are used directly in air treatment plants, as well as in the end points of air supply to the room as the final cleaning level. The effectiveness of these filters for particles of 0.3 μm particles varies from 97.8 to 99.995%. Such filters are designed for rooms having a purity class of 100-100,000.
ULPA filters (also known as Ultra-HEPA). These are very effective special. air filters. The effectiveness of these filters for particles of 0.3 μm particles lies in the range from 99.9999 to 99.99995%. Such filters are designed for rooms having a purity class 1-100.
DOP test. Check the effectiveness of HEPA filters in real conditions after installation.
Clean rooms with turbulent air flow. In such clean rooms, air conditioned air is supplied through HEPA filters located directly in the suspended ceiling. Air refund holes are at the floor level. This cleaning method is designed for premises with a purity class of 10,000-100,000 (Fig. 1).
Clean rooms with laminar air flow. In this method, the flow of air flowing at constant speed tolerates pollutants into the return air channel, and then to the air treatment plant. This method is suitable for premises with a class of purity 1, 10, 100, 1000
Clean rooms with laminar air flow
Air gateway. At the entrance to the clean room there must be an air gateway, providing access to the room according to the rules. The air gateway is a small chamber with two doors, in which air-conditioned air is served through two HEPA filters.
Class of cleanliness of the room.Depending on the type of production, which should be performed in a clean room, the class of purity of this room is determined. For the classification of clean rooms, various standards apply. Currently, the VDI 2083 standard is used in Germany, in France - US 209 in AFNOR 44001, in England - BS 5295.
In the clean room, all equipment and all systems (including air treatment installations, air ducts, channel equipment) Must be able to clean, replace and service.
In the premises in which a high degree of sterility is necessary, a three-stage filtering is used:
Clean room components
Running procedures for clean rooms.After completion of test procedures and commissioning, under the positive results of these procedures, work can be started in the clean room.
The most important tests for clean room are: testing air ducts on density, air treatment devices - to ensure the desired flow, diffusers - to ensure the specified temperature and humidity values, pressure tests and measurement of comprehensive substances. Applications used for these purposes should be repeated calibration before testing.
Outdoor air processing devices, exhaust dampers, parameters, parameters, filter labels, and all sections of the air processing system should have free access and possibilities of visual control and service.
Another important problem is to train pure room personnel. Be sure to use sterile clothing personnel.
As well as for many engineering systemsIn the clean room there must be regular maintenance procedures aimed at ensuring continuous operation without accidents and troubleshooting. To continuously maintain hygienic parameters, it is necessary to regularly check the filters for clogging before any problems occur.
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INTEH company produces a full range of works related to the design, supply of equipment and materials, as well as directly by installing complexes engineering equipment and "clean premises" systems for heating, ventilation and air conditioning with multistage, high-quality air filtration system (air purification). Using specialized climatic equipment for cleaning clean rooms in industries:
Class of purity room - This is clearly regulated by the level of content in the air of various kinds of impurities and particles. Cleanity classes differ in the number of colony-forming bacteria per unit volume.
On the example of clean rooms of medical institutions - installed 3 classes of purity:
Technological requirements for ventilation and air conditioning systems for clean rooms » They are as follows:
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The task of ensuring cleanliness in the room most effectively solved on the basis of a comprehensive approach, which takes into account both specific features of each particular room (volume-planning characteristics, technological purpose imposed on cleanliness requirements and climatic parameters) and features characterizing the room as an element of the set of premises. This provision is reflected in the creation of clean rooms complexes, the basic principles of the design of which are:
Constructive execution The complex is determined by the specific purpose of clean rooms, their configuration and dimensions acting regulatory requirements To the air. IN general The proposed inteach complexes are performed according to the modular principle and include the following functional systems and elements:
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When designing ventilation systems for clean rooms used in the production of microelectronics, laboratories of medical institutions, operating, aseptic chambers and departments, premises with a 3D printer, etc. - It is necessary to follow the norms and requirements of the GOST, based on the recommendations of the customer and the required class of purity.
Sanitary standards, technical tasks, manuals and installation rules
The main rule of the modern designer "clean" ventilation is an individual approach that excludes standard solutions. The basis for organizing the right air exchange "clean" premises is the following requirements and norms:
Modern project recommendations proceed from the mandatory requirement that air prepared for the premises of medical institutions, laboratories, operating and aseptic departments should be sterile. The implementation of such a project requires the installation of industrial antibacterial filters with a high lower threshold of harmful particles and microorganisms - HEPA and ULPA.
In the production of microelectronics uses zonal ventilation of unidirectional and mixed type. The class of cleanliness of such an object varies, depending on the zone - working, technological (maintenance), service.
For clean room with a 3D printer, a separate room is planned. Maintaining the required cleanliness is ensured by setting additional devices Air conditioning, transfer window or gateway.
In industrial, warehouse, office, medical complexes of clean rooms and rooms, a modular ventilation circuit is used, including air distributors, air filters, gear radiation, boxes and windows, monitoring and automation systems. The finishing of ventilation equipment and air conditioning channels is made by special sealants. The construction of such objects is carried out from special materials - plastic, plastering wall panels, sandwich panels for suspended ceilings, curving plinth profiles, hermetic doors, windows and lamps, floors with sticky rugs. Metal furniture is selected to minimize air pollution. Clothes, shoes, technological equipment is stored in isolated lockers and boxes.
An important point of the process of designing clean complexes is the proper production practice - GMP standard, which allows not only to calculate the cleanliness class for the technological environment of the room or room, but also responsibly perform installation of air conditioning and ventilation systems. Object for the production of microelectronics, pharmaceuticals, medical equipment, food, etc. It should not only undergo certification of climatic equipment, but also to undergo continuous monitoring of its work, including service, maintenance, disinfection and cleaning.
While doing design work In the Medical Center, Moscow Doctor specialists of our company made the calculation, supply, installation of ventilation and air conditioning systems for its clean premises. GOST Requirements were performed on ISO-2002, taking into account class 5 ISO purity on suspended particles.
Air supply was carried out by a fence device with prom. SHUFT fan transmitting air through a multistage system with a HEPA filter. The heat recovery and air recirculation in the pure aseptic room of the clinic was carried out by the Funke heat exchanger. The required degree of sterility was maintained by the gear ratio.
At the request of the customer, 2 modes of operation of the ventilation equipment were prepared. Clean ventilation mode has served air through a separate automation unit that is not associated with other premises of the building of the medical facility. The second mode allowed the air exchange control from the displicerization remote control, in order to emergency alert, in the absence of personnel in the building.
The purpose of the projected aseptic separation in the medical center is operating and sterilization. In a clean room, procedures for the treatment of dermatitis should have been carried out.
This type of dermatitis refers to rare skin diseases. Most often, representatives of the beautiful half of humanity aged 20 to 40 years are subjected to this skin disease. Doctors - Dermatologists Sometimes perioreral dermatitis is called the near-theft dermatitis or nearly. The latter disease comes from the name of its location.
Very often the beginning of the periorel dermatitis is expressed by several pimples on the skin in the mouth. Patients complain that from the use of ordinary hygienic tools that prevent acne rash, it becomes only worse and the area of \u200b\u200bthe affected area increases. It should be immediately applied to a medical center, which specializes in skin diseases, if you have the following symptoms:
The skin on the chin and around the mouth is covered with a pronounced rash. Red rash, itching of the affected skin. The skin seems to be tightened.
Acne around the mouth occupy not the entire area of \u200b\u200bthe skin, but some areas. That is, located localized areas.
Sometimes it is accompanied by pimples containing heads filled with transparent liquid. When these heads are bursting, then the liquid contained in them hits the skin. Red rash with time turns into ulcers.
The affected areas of the skin are covered with transparent scales, which periodically peel off the surface and disappear. Such symptoms may also be in other diseases of the human body.
Like any dermatitis, this is caused by a decrease in the protective function of the skin. The following factors can provoke failures in the immune system:
The skin reaction may appear from the use of allergenic medicines. Before starting treatment from any disease, the doctor must ensure that there are no allergies in the patient to the components of the drug elements.
The cost of designing the ventilation of clean room - from 199 rubles. For 1 m2
In the climate company, Stroinzhinirring LLC will perform projects for public catering facilities (dining rooms, cafes, restaurants), industrial workshops (welding places, paint cameras), workshops (jewelry, microelectronics), health care facilities (medical and preventive complexes, pharmacies, pools, maternity homes, laboratories), office, server, residential, warehouse and commercial premises (shopping centers, shops) - in accordance with modern requirements, GOST parameters and lower standards.
High-tech, convenient and practical air purification scheme for private and state medical centers, rented and "their" clean premises in Moscow and the region - with dispatching? We offer honest and "clean" prices (without cheating) on \u200b\u200bdesign and installation work followed service For construction and repair organizations, owners of sports clubs, tenants, health facilities and catering establishments!
The services of our organization include the selection and installation of specialized equipment for air gateways and transfer windows. Industrial air conditioners, filters, air distributors, control blocks, recuperators, etc. Create optimal conditions To perform any tasks on your "clean" objects.
Previous material - ventilation of residential premises!
For health facilities, scientific centers, as well as enterprises for the production of microelectronics and medicines suitable ventilation systemswhich are designed for "clean rooms".
"Pure" is considered to be a premises with all structures related to it, in which the concentration of microorganisms and particles in the air is maintained at the level, which is determined by SNIP 41-01-2003 (8) and GOST ISO 14644-1-2002. Its classes of cleanliness and sanitary standards are also available in the USA and EU countries.
Depending on the number of suspended particles in size from 0.1-5.0 μm per 1 m 3 in the clean room, 9 classes of sterility are set.
For example, class 5 ISO has 2 subspecies:
For clean rooms, an appropriate ISO category is used and one of these states: "equipped", "built" or "exploited".
The organization of air conditioning and inflow systems is a time-consuming process that requires specialized knowledge, the presence of certain tools and specific engineering solutions.
Air flows in such a room must be supplied already filtered from microorganisms, bacteria and pollution, so one of the main roles in creating a favorable microenvironment in clean rooms is assigned to the supply air purification system. The mounted filtering system is the installation after the injection fan of several groups of cleaning elements:
In addition to filtering devices in the ventilation of clean rooms, air intake and air distribution units, gateways, fixtures are involved: automatic maintenance The required temperature and humidity, fans, as well as shut-off and regulating devices. The choice of a certain set of equipment depends, first of all, from the purpose of clean rooms and the air mass purity class item is necessary for the operation of this object.
In the process of developing clean premises, a large attention should be paid to the design and material manufacturing material and filter chambers that need to be systematically processed with the purpose of antimicrobial prophylaxis.
To maintain the purity of air in the premises, it is necessary to use ventilation with an excessive amount of influx, compared to exhaust installation In the cabinets adjacent to it.
Such an air exchange system does not allow penetration into the room pollution and contributes to the movement of air from a clean cabinet to related rooms with it. Much attention is paid to the options for inlet of air flows into clean rooms and depends, as a rule, on their purpose.
The air intake in the room with a class of purity 1-6 provides air distribution vehicles that are uniformly guide air masses with a speed of 0.2 to 0.45 m / s. In the cabinets with a lower level of purity, the creation of a non-unidirectional stream is allowed, for this, ceiling diffusers are operated. The multiplicity of air exchange in clean rooms is 25-60 times in 60 minutes.
When developing air ducts, one of the most acute problems is a competent airflow device. Currently, 5 ways of location of air distribution devices are most commonly operated, the choice of which directly depends on the purpose of clean rooms. Consider these schemes:
The exhaust flow of operational is carried out due to exhaust fans and supply gratings equipped with check valves.
Practice has shown that the best device for creating a unidirectional air flow in the operating room is ceiling mesh air distributors. For example, the laminar ceiling with a size of 1.8x2.4 meters in the operating room, the area of \u200b\u200bwhich reaches 40 m 2, will allow to organize a 25-fold exchange of air at the speed of air masses from the instrument 0.2 m / s. These indicators are enough to assimilate excess heat from the functioning of the technique and the number of health workers in the operating room.
The development of ventilation and air-conditioning systems in clean rooms is a complex process that requires a person to understand the air exchange processes and the intricacies of the use of air distribution units. It is for this reason that for the assembly of the whole design at such objects it is necessary to contact only the masters of their case.
