Balance holes should not be overly open, as they can significantly affect the pump's efficiency. This section explains how axial thrust is managed in pumps. For single-stage pumps, there are several common methods to balance axial forces: 1. **Drilled Balance Holes** A few small holes are drilled near the hub of the rear impeller cover, and a sealing ring is installed. The outer diameter of the seal matches the suction inlet of the impeller. During operation, the liquid behind the cover connects with the suction inlet, creating similar pressure levels. The area outside the seal on the rear cover is equal to the area outside the front cover’s suction port, balancing the total force on both sides. This reduces the unbalanced axial force that the bearing must handle. Normally, this method works well for balancing axial forces. However, it causes more leakage, which interferes with the normal flow through the impeller, reducing pump efficiency by about 2-5%. It is typically used in small single-stage centrifugal pumps. 2. **Balancing Pipe** This method is similar to using balance holes. A mouth ring is placed on the rear cover of the impeller, aligned with the suction inlet. A balance pipe then directs the liquid from the sealed space back into the pump’s inlet. This helps balance the axial force. The cross-sectional area of the balancing pipe should be equal to or larger than the flow area of the mouth ring gap by 4–5 times. 3. **Balancing Vanes** Radial vanes are installed symmetrically on the rear side of the impeller. As the impeller rotates, these vanes accelerate the liquid on the backside, increasing centrifugal force and reducing the pressure on the rear of the blade. This helps balance the pressure on both sides of the impeller. The effectiveness depends on the size of the vanes and the clearance between them and the pump casing. However, this method also reduces overall pump efficiency. 4. **Double-Suction Impeller** In single-stage or some multi-stage centrifugal pumps, a double-suction impeller is used. This design naturally balances the axial thrust due to its symmetrical inlet. However, in practice, it is challenging for manufacturers to make both sides of the flow components exactly identical, so a small residual axial force still exists. This force is usually supported by a single-row radial ball bearing at one end of the shaft. In addition, for multi-stage pumps, other axial balancing methods include symmetric impeller arrangement, balanced hub design, and balancing disc systems. Each approach has its own advantages and limitations depending on the pump type and application.

Finned Tubes

A finned tube is a heat transfer device consisting of many parallel metal fins commonly used for heat dissipation and cooling applications. Finned tubes increase the surface area of the pipe, thus increasing the heat transfer efficiency. Finned tubes are commonly used in applications such as air coolers, automotive radiators, condensers, and evaporators. They are also used in industrial heaters and refrigerators to increase heat transfer surface area and improve efficiency.

Finned tube is a kind of new, wear-resistant, efficient heat exchange material, is a kind of energy-saving heat exchange element, it uses high-frequency power source as heat source, the steel strip, steel pipe heating at the same time, so that the fusion welding together into one, with high heat exchange efficiency, large cooling area, long service life, adapt to a wide range of temperature, high pressure characteristics, it can also be made of a variety of materials, Excellent heat transfer, durability, heat resistance and corrosion resistance. Widely used in waste heat recovery, petrochemical, power plant boiler, economizer, bus, industrial and civil construction heating, refrigeration, medical drying, wood drying, food drying system and other industries.

The main business scope is various heaters, waste heat boilers, pressure vessels, supportingair preheaters, air coolers, furnace accessories and accessories, and provide equipment installation, with EPC ability of projects. At present, our customers have covered all large and medium-sized petrochemical enterprises in China and established long-term strategic cooperative partnership with them. Products are exported to Southeast Asia, Middle East, and other regions.

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