Spiral Plate Heat Exchanger

Spiral Plate Heat Exchanger

Overview
A spiral plate heat exchanger is a heat exchange equipment suitable for heat transfer between steam-gas, steam-liquid, and liquid-liquid. It is used in industries such as chemicals, petrochemicals, solvents, food, light industry, textiles, metallurgy, rolling steel, and coking. It can be divided into non-detachable (Type I) spiral plate heat exchangers and removable (Type II, Type III) spiral plate heat exchangers according to the structural form.
Spiral plate heat exchangers, proven over many years of practical use, are indeed a type of heat exchange equipment suitable for applications in industries such as chemistry, petroleum, solvents, food, light industry, textiles, metallurgy, rolling steel, and coking. The product structure and technology of the heat exchangers comply with the Swedish "Alfa Laval" company standards, featuring argon arc welding with folded edges on the spiral plate ends and a "top distance column" special process for capacitive contactors, which enhances both internal and external quality and has been approved by Baosteel, capable of replacing imports.
The non-separable helical plate heat exchanger is designed according to the form of the non-separable helical plate heat exchanger specified in the JB/TQ724-89 machinery department standard, with provisions for basic parameters and dimensions. It boasts advantages such as simple manufacturing, low cost, compact size, and good heat transfer performance. However, it also has its drawbacks, such as the inability to be mechanically cleaned and difficulty in repair if damaged. Users should select the appropriate equipment based on the actual conditions of the project to ensure its effectiveness.

Structure and Performance
1. This equipment is suitable for liquid-liquid, gas-gas, and gas-liquid heat transfer, which can be used for steam condensation and liquid evaporation heat transfer in industries such as chemicals, petrochemicals, machinery, electricity, light industry, and textiles.
2. This equipment is made from two steel plates rolled into two even spiral channels, allowing for full countercurrent flow with two heat transfer cutoffs. It is suitable for heat transfer with small temperature differences, facilitates the recovery of low-temperature heat sources, and can accurately control the outlet temperature.
3. The transition on the housing is tangential, with minimal local resistance. The helical passage has a uniform curvature, and there is no significant change in direction of fluid flow within the equipment. As a result, the total resistance is low, allowing for an increased design flow rate, thereby enhancing its heat transfer capacity.
4. The ends of the helical channel are welded and sealed, providing good sealing performance and reliable structure.
5. Difficult to repair, especially when internal plates are problematic; some factories remove all welds at both ends of the equipment, reflatten the plates, weld them again, and then roll them back. This process consumes an excessive amount of labor hours, making the anti-corrosion of spiral plate heat exchangers particularly important.
6. Not suitable for mechanical cleaning; production practice has proven that spiral plate heat exchangers are less prone to clogging compared to conventional tube bundle heat exchangers. Particularly, suspended particles like silt and small shells are not easily deposited in the spiral channels. The analysis of the reasons: Firstly, it is because the single-channel contaminants are flushed out as soon as a circulating flow is formed; secondly, because there are no dead ends in the spiral channels, contaminants are easily washed out.
7. Due to the presence of spacers within the helical channels to maintain spacing, there must be no fibrous impurities (cotton yarn, straw sticks, leaves, etc.) entering the heat exchanger.
8. Strictly control the outlet temperature of the cooling water below the scaling temperature.
9. Common cleaning methods include steam blowing and alkali washing. Steam should be blown into the inlet to expel impurities from the equipment, and many manufacturers find this approach to be effective.

Detachable Spiral Plate Heat Exchangers (Type II, Type III) Overview
The structural principle is essentially the same as that of a non-disassembled heat exchanger, but the channels can be disassembled for cleaning, and both ends are sealed with heads. Particularly suitable for liquid-liquid exchanges involving sticky or sedimentary liquids, as well as gas-liquid and steam condensation. Due to the need for additional components like heads and flanges, the equipment cost of the disassembled heat exchanger is slightly higher than that of the non-disassembled type.

Basic Parameters
The nominal pressure PN for spiral plate heat exchangers is specified as 0.6, 1, 1.6, and 2.5 MPa (equivalent to the original 6, 10, 16, and 25 kg/cm²), referring to the high working pressure of a single channel. The test pressure is 1.25 times the working pressure.
The material for the contact part of the spiral plate heat exchanger with the medium is carbon steel Q235A, Q235AF, and stainless steel acid steel SUS321, SUS304. Other materials can be selected according to customer requirements.
 Allowable working temperature: carbon steel t=0～+350°C, stainless steel and acid-resistant steel t=-40～500°C, the temperature and pressure reduction range shall comply with the relevant regulations for pressure vessels. When selecting this equipment, appropriate process calculations should be made to ensure the fluid in the equipment channel reaches turbulent flow. (Generally, liquid flow rate is 1m/s, gas flow rate is 10m/s).
A single unit may not meet the usage requirements; multiple units can be combined, but they must adhere to the following specifications:
Parallel and Series Combinations: Same spacing between equipment and channels. Mixed Combination: One channel in parallel, one channel in series.
不锈钢PN0.6, 1.6MPa Non-Removable (Type I) Spiral Plate Heat Exchanger

Key Technical Parameters