What causes subpar heat transfer in heat exchangers? (1) Scaling on heat exchange tubes (2) Poor water quality, oil contamination, and microbial presence (3) Baffle short circuit Addressing inadequate heat transfer in heat exchangers: (1) Chemical or jet flow cleaning to remove scaling (2) Enhanced filtration and water quality management, along with media purification (3) Replacement of pipe box gasket or partition
What causes seal leakage at the heat exchanger flange? (1) Gaskets under pressure, corrosion, or deterioration. (2) Weak, loose, or corroded bolts. (3) Flanges lacking rigidity with sealing surface defects. (4) Non-parallel or misaligned flanges. (5) Poor-quality gaskets. How to address seal leakage at the heat exchanger flange? (1) Tighten bolts and replace the gasket. (2) Upgrade bolt materials, fasten, or replace bolts. (3) Replace or address defects in the flange. (4) Repair or replace the flange....
What causes inner leakage between two media in the heat exchanger? (1) Corrosion-induced perforation and cracking of heat exchange tubes (2) Cracking of the expansion joint between heat exchange tube and tube plate (3) Seal leakage at the float head flange of heat exchangers (4) Seal leakage of threaded tight-ring type heat exchanger tube plates How to address internal leakage of two media in the heat exchanger? (1) Replace or block the leaking tube. (2) Re-expand (repair welding) or block as needed....
The common faults and treatment of heat exchangers are shown in Table 2-2. No. Fault Cause Solution 1 Two kinds of media mingling together (internal leakage) Corrosion perforation and cracking of heat exchange tubes Cracking of the expansion mouth (welding mouth) of the heat exchange tube and tube plate Sealing leakage of float head flange heat exchangers Sealing leakage of tight-ring type heat exchanger tube plates Replace or...
What methods can be employed to enhance heat transfer in heat exchanger equipment? One primary method is to increase the heat transfer surface area through various structural modifications: (1) Utilizing finned tubes, nailhead tubes, threaded tubes, spiral tubes, or bellows. (2) Machining the surface of the pipe with spiral grooves or threads. (3) Employing smaller diameter pipes to increase the number of pipes within the same tube plate area, thereby augmenting the heat transfer area. Another approach...
Why is the repair and maintenance of heat exchangers essential? In oil refining and chemical production, the fluids circulating through heat exchangers often contain deposits like coke, posing a risk of corrosion. Over time, these conditions lead to the accumulation of scale and rust in crucial parts such as heat exchange tubes and shells. This not only diminishes heat transfer efficiency but also reduces flow cross-sections, elevating resistance and potentially causing blockages. Moreover, dielectric...
What are the maintenance standards for heat exchangers? (1) During the operation, pulling, loading, transportation, and hoisting of heat exchanger bundles, avoid directly tying the exposed wire rope to prevent damage to the heat exchange tubes. (2) Clean the internal and external structures of the tube bundle. (3) Process gaskets as a whole when tube boxes and floating heads have partitions to ensure effective sealing without defects. (4) Tube bundle plugging: Limit the number of blocked pipes within...
The heat exchanger's operational cycle must align with the production device's production cycle to ensure normal operation and meet production requirements. Regular inspection, supervision, and daily maintenance and repairs are essential. Ensuring stable pressure is crucial, and overpressure operation is strictly prohibited. Leakages, often occurring during line sweeping start-ups and shutdowns, particularly in the floating head, require careful attention. When repairing, checking the pressure...
How are Finned Tubes Classified in Finned Tube Heat Exchangers? Finned tubes can be categorized into two fundamental types, longitudinal and radial, based on their structural form. Other variations are developments or modifications of these two types. Fin shapes include round, rectangular, and needle-shaped. Additionally, fins can be positioned outside the tube (outer fin tube) or inside the tube (inner fin tube), or a combination of both. Manufacturing processes classify finned tubes into integral...
1. What are the Basic Types of Air Coolers? The fundamental types of air coolers include Horizontal Air Coolers, Vertical Air Coolers, and Inclined Air Coolers. 2. How to Classify Air Coolers According to the Cooling Method? Air coolers can be categorized based on the cooling method into Dry Air Coolers, Wet Air Coolers, Dry and Wet Combined Air Coolers, and Spray Air Coolers on Both Sides. 3. How to Classify Air Coolers According to the Type of Their Tube Bundle Layout? Air coolers can be classified...
1. Definition of Wet Air Cooler A wet air cooler is a type of air cooler where a slight structural modification allows for the spraying of a small amount of water onto the fin surfaces. This addition of water facilitates evaporation, enhancing heat transfer and improving overall heat transfer efficiency. 2. Classification of Heat Exchangers based on Heat Transfer Principle Heat exchangers, according to the principle of heat transfer, can be categorized into three types: mixed, regenerative, and...
The pressure testing of a heat exchanger involves both hydraulic and pneumatic tests. In principle, the primary method for pressure testing is the hydraulic test, commonly referred to as the hydrostatic test when clean water is the testing medium. If other liquids are utilized, they must be non-hazardous, and their temperature should remain below the boiling point. When conducting a hydraulic test with a flammable liquid, the test temperature must be below the liquid's flash point. Additionally,...