General requirements of pharmaceutical industry for sanitary container design
In pharmaceutical water system, sanitary pressure vessels are widely used, such as softened water tank, purified water tank and water for injection tank, which are atmospheric pressure vessels or pressure vessels with sanitary requirements.
The purpose of design and construction of sanitary container is to protect the product to the maximum extent. The contact surface of the product will not pollute the product during the process and it is easy to clean, reduce the dead angle of breeding chemical or microbial pollution, and provide convenience for cleaning, maintenance and inspection.
The general requirements of pharmaceutical industry for the design of sanitary containers include the following contents:
- 1) The design, selection and installation of the equipment should meet the production requirements, the structure should be simple, and the parts that need cleaning and sterilization should be easy to disassemble; The equipment that is inconvenient to be disassembled and assembled shall be equipped with a cleaning port and a manual cleaning or automatic cleaning device;
- 2) The surface of the equipment should be smooth and easy to clean, and the inner wall of the equipment in direct contact with the material products should be smooth, flat, easy to clean, corrosion-resistant and avoid dead angle. According to the different requirements of the fluid cleanliness level, mechanical polishing or electrochemical polishing can be used to achieve different surface treatment requirements;
- 3) The internal surface of the equipment in direct contact with materials shall be made of materials that do not react with them, release particles or absorb materials. Generally, austenitic stainless steel shall be used. Glass lined equipment shall not be used as far as possible. Rubber lining, glass fiber reinforced plastics and other materials that are easy to release particles or absorb materials shall not be used. The materials shall be non-toxic and corrosion-resistant, 316L ultra-low carbon stainless steel shall be used as sanitary container for injection preparation and injection water storage;
- 4) The transmission parts of the equipment shall be well sealed to prevent the leakage of lubricating oil and coolant from polluting raw materials, semi-finished products, finished products and materials. Packing seal is generally not recommended for the sealing of transmission parts;
- 5) In addition to meeting the above requirements, the equipment with process requirements for microorganisms should also meet the requirements of disinfection and sterilization;
- 6) Except for special requirements, it is not suitable to install anchor bolts for equipment in clean area;
- 7) The surface of the insulation layer of the equipment must be smooth and smooth, and no particulate matter shall fall off. The surface shall not be covered with asbestos cement foam, and the spliced and flaky insulation shall not be used. The metal shell shall be used for overall protection;
- 8) For the equipment producing noise and vibration, noise elimination and vibration isolation devices should be adopted to improve the operating environment. During the dynamic test, the indoor noise level should not exceed 75 dB;
- 9) Sanitary flange, Na connector, kest connector or clamp connector should be used for piping connection, and polytetrafluoroethylene or sanitary rubber should be used as sealing material;
- 10) Accessories on equipment or machinery, such as instruments, metering devices and liquid level meters, shall be arranged reasonably, the counting shall be accurate, the regulation and control shall be stable and reliable, the material requirements shall be the same as the equipment body, and the connection form shall meet the requirements of cleaning, disinfection and sterilization;
- 11) The equipment design should be standardized, generalized, serialized and Mechatronic as far as possible, and the continuous sealing and automatic detection in the production process are the guarantee for the full implementation of GMP requirements;
- Cold rolled steel plate shall be selected as the first choice for vessel manufacturing, and shall be treated by solid solution and acid pickling. Polished plate shall be used as far as possible. Pressure parts such as manhole, handhole, sight glass, vessel flange and pipeline flange shall be made of integral stainless steel, and lining, lining ring, composite, surfacing and coating shall not be used.
- Stainless steel lining structure is not allowed for sanitary vessels, because stainless steel lining can not ensure the complete fit with carbon steel tank, and there is residual air in the gap. During steam sterilization, the material will be heated and expanded. Due to the different expansion coefficients of stainless steel sheet, carbon steel tank and residual air, the plug welding part will fall off and micro cracks will occur, The liquid in the tank will form a “dead angle” between the stainless steel lining and the carbon steel tank through cracks. The inner wall and internal structure of sanitary containers should be designed to avoid dead angle, so as to avoid incomplete sterilization caused by ineffective or insufficient steam.
There are three kinds of hygienic aseptic connection methods:
The most common connection mode in pharmaceutical water system is clamp connection. It is necessary to install sealing ring in the joint seal and fasten with clamp. Na aseptic connection and kest aseptic connection are two new sanitary grade connection modes. These two designs effectively avoid pollution risk caused by dead corner of pipeline interface, especially in the aseptic guarantee of side wall accessories installation of tank body, Now it has been widely used in aseptic pharmaceutical industry.
After finishing the tank itself and connecting the device, let’s take a look at the spray device. This is another important tank accessory of sanitary pressure vessel. In the pharmaceutical water system, the full wetting of the inside surface of the tank can help the system to clean itself and prevent microbial reproduction, and also ensure the temperature inside the tank is even, The spray device mainly functions as spray cleaning and wetting the surface of the tank.
According to the different working pressure, the spray device for the pharmaceutical water tank mainly includes two categories: fixed cleaning ball and tangent water cleaning ball. In addition, it can also be classified according to different cleaning angle and installation mode.
The fixed cleaning ball belongs to the low pressure and high flow cleaning ball. The principle is that small cleaning fluid is continuously sprayed from each hole of the fixed cleaning ball to the fixed point on the inner wall of the tank body. The cleaning liquid is distributed to the inner surface of the tank by laminar flow. The working pressure is relatively moderate 1.5-6bar, and the impact force is relatively weak during cleaning. In order to achieve the cleaning effect, a large amount of cleaning fluid is required, Mainly used for cleaning tasks or surface wetting functions with lower requirements.
Because of its non rotating characteristics, it has been recognized by some enterprises. However, the pressure and flow of water return for injection are limited by the design and operation of pharmaceutical water system. The cleaning effect is general, the cleaning pressure is relatively high, the water consumption and the amount of cleaning agent are very large, and the cleaning holes are easy to block and red rust, and have been gradually replaced by the tangent water cleaning ball.
Tangent water cleaning ball is also called rotary cleaning ball, which belongs to low pressure and low flow cleaning ball. It is composed of outlet sphere and a connecting rod with high speed rotation. It makes the cleaning ball rotate rapidly by using the impact force of water flow on tangent outlet sphere. Its working principle is that the cleaning liquid is continuously ejected from tangent water by fan-shaped eddy current, The cleaning liquid is evenly sprayed to the surface of the tank by combining vibration mode with physical impact force.
The working pressure of the tangent water cleaning ball is moderate, and the impact force is relatively strong during cleaning. Only a few cleaning agents are needed to obtain ideal results, mainly used for the tank body which is easy to clean. The professional wear test of rotary cleaning ball shows that the mass loss of spray device is about 90mg after 1100 hours of continuous operation under the pressure of 2.7bar. According to the quantity of spray cleaning solution, the theoretical concentration of iron chip falling off is 0.0052 micrograms / L, which is far lower than the quality standard of iron concentration in pharmaceutical industry.
The spray device with high speed rotation must avoid the risk of particulate pollution caused by dry rotation. Compressed air or other inert gas is not allowed to be used for purging operation, otherwise serious red rust and particle pollution will occur, which is also the place that special attention is needed in the use of tangent water cleaning ball.
Source: China Pressure Vessels Manufacturer – www.secmachinery.com
www.secmachinery.com is one of the leading china filtration equipment & sanitary stainless steel pressure vessels manufacturer, with professional factory. We focus on the sanitary pressure vessels, filtration equipment research and development, manufacturing, sales and service since the company been established. Our products is widely used on bio-pharmaceutical, food and beverage, fine chemical industry.
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