【Q&A】Catalytic Coking Reformate Blending Version 20170917
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Participation: Prize of 5 Wealth； Correct answer: Reward of 10 wealth points ； Note: This post is valid for 48 hours. Question: What is cavitation? Answer: When the pressure at the inlet of the impeller is lower than the saturation pressure of the working medium, part of the liquid evaporates. Once these vapor bubbles enter areas with higher pressure, they condense suddenly due to the increased pressure; as a result, the surrounding liquid flows in to fill that space, causing hydraulic shock. This phenomenon is known as cavitation. http://bbs.hcbbs.com/static/image/hrline/1.gif http://bbs.hcbbs.com/static/image/hrline/2.gif The answer will be announced automatically in two days. Petrochemical Section – “Creative Ideas for Energy Savings” campaign (the second phase is currently in progress). http://bbs.hcbbs.com/thread-1666758-1-1.html [Daily Question] Summary of 2017 data on catalytic coking and reforming oil blending. http://bbs.hcbbs.com/thread-1811219-1-1.html [Q&A] Summary of 2017 data on catalytic coking and reforming oil blending. http://bbs.hcbbs.com/thread-1826018-1-1.html
When the installation height of a centrifugal pump is increased, the pressure inside the pump decreases; the lowest point of pressure within the pump is usually located near a point slightly downstream of the inlet to the impeller blades. When the pressure here drops to the saturated vapor pressure of the liquid being transported, boiling occurs; the vapor bubbles formed then rapidly condense due to the sudden increase in pressure as the liquid flows from the inlet toward the periphery. This causes the liquid to rush towards the center of the bubble at high speed, generating impacts with very high frequencies and intense instantaneous pressures; this phenomenon is known as cavitation.
Cavitation refers to the phenomenon that as the installation height of a centrifugal pump increases, the pressure inside the pump decreases. The lowest point of pressure within the pump is usually located slightly downstream of the inlet of the impeller blades; liquid rushes toward the center of the bubbles at high speeds, resulting in high-frequency, intense pressure spikes. This phenomenon is known as cavitation.
Answer: It refers to the situation where an increase in the installation height of a centrifugal pump leads to a decrease in the pressure inside the pump. The lowest point of pressure within the pump is usually located slightly downstream of the inlet to the impeller blades; liquid rushes toward the center of the bubble at high speed, resulting in impacts with very high frequencies and intense instantaneous pressures. This phenomenon is known as cavitation.
When the pressure at the impeller of a centrifugal pump is lower than the saturated vapor pressure of the liquid, the liquid begins to vaporize, generating numerous bubbles. When the bubbles enter the high-pressure area along with the fluid, they rapidly condense and burst under the influence of the high-pressure liquid. At this point, the fluid rushes into the space previously occupied by the bubble at an extremely high velocity, creating a localized hydraulic shock.
When the pressure at the impeller of a centrifugal pump is lower than the saturated vapor pressure of the liquid, the liquid begins to vaporize, generating numerous bubbles. As these bubbles move with the fluid into high-pressure areas, they rapidly condense and burst under the influence of the high-pressure liquid. At this point, the fluid rushes at extremely high speeds into the space previously occupied by the bubbles, creating a localized hydraulic shock.
When the pressure at the inlet of the impeller is lower than the saturation pressure of the working medium, part of the liquid evaporates. Once these vapor bubbles reach areas with higher pressure, they condense suddenly due to the increased pressure; as a result, the surrounding liquid flows in to fill that space, creating a hydraulic shock. This phenomenon is known as cavitation
When the pressure at the inlet of the impeller is lower than the saturation pressure of the working medium, part of the liquid will evaporate (i.e., vaporize). After evaporation, when bubbles enter areas with higher pressure, they condense suddenly due to the pressure, and the liquid surrounding them flows in to fill that space, resulting in a hydraulic shock. This phenomenon is known as cavitation. This continuous localized impact load causes gradual fatigue damage to the material’s surface, leading to erosion of the metal surface and the formation of honeycomb-shaped cavities of various sizes. The instability associated with cavitation results in vibration and noise in the pump; moreover, as bubbles block the channels within the impeller during cavitation, both flow rate and head are reduced, and efficiency declines. Therefore, it is necessary to prevent cavitation from occurring.
When the pressure at the inlet of the impeller is lower than the saturation pressure of the working medium, part of the liquid evaporates. Once these vapor bubbles reach areas with higher pressure, they condense suddenly due to the increased pressure; as a result, the surrounding liquid flows in to fill that space, creating a hydraulic shock. This phenomenon is known as cavitation
The phenomenon of gas accumulating inside the pump and impacting the impeller
When the saturated vapor pressure of the liquid equals the surrounding pressure, the liquid boils and a large number of bubbles are formed. When these bubbles reach the high-pressure area of the impeller, the gas condenses, the bubbles burst, creating voids; the liquid surrounding them then rushes into these voids at extremely high speeds, thereby damaging the impeller.