Characteristics, Structure, and Working Principle of Spiral Plate

Characteristics, Structure, and Working Principle of Spiral Plate

Spiral plate is a new type of widely used heat exchange equipment, which has a series of advantages such as high heat transfer efficiency, low resistance loss, stable and reliable operation, compact structure, and low price. Since the late 1960s, China has been researching, manufacturing, and formulating corresponding technical standards. It has accumulated a lot of experience in manufacturing and use, and is now widely used in industrial sectors such as petrochemical refrigeration, organic chemical food, dye alkali pharmaceutical, machinery, metallurgy, etc. It has been the first of its kind in China for nearly a decade and has achieved excellent results. The spiral plate strong oil-water cooler is a spiral body made of two 2-3mm thick coils rolled into two uniform spiral channels. At the beginning and end of the two spiral channels, namely the upper and lower parts of the spiral body and the tangential direction of the outer edge, connecting pipes and flanges are welded respectively. There is a type of heat carrier (oil and water) in each channel in a fully countercurrent state for heat exchange. The cooling area is the product of the unfolded length of two steel plates and the width of the steel plates. In order to enhance the stiffness of the steel plate and increase the critical pressure of the spiral body, fixed distance columns with a certain density are welded on the same phase surface of the two steel plates. This can also increase the fluid flow, increase the Reynolds number, and improve heat transfer efficiency.

Due to the uniform curvature of the spiral channel, there is no significant reversal of the fluid in the channel, resulting in low resistance and no dead corners. In order to improve the heat transfer efficiency, the flow rate of the long cylinder fluid in the channel is relatively high, which can prevent channel fouling, and the channel itself has self-cleaning function. In addition, there are exhaust (liquid) holes left in the two spiral channels for easy operation and can be used for sampling and testing.

1、 Main parameters and installation dimensions of BLS6 type transformer with strong oil-water cooler series

Example: BLS6-160 is a non detachable spiral plate cooler made of stainless steel acid resistant design pressure of 0.6Mpa, with a heat exchange area of 16m2 (cooling capacity of 160).

2、 Characteristics

1. High heat transfer efficiency

The total heat transfer coefficient can reach up to 3300KCal/m2. h. ℃, and the heat transfer effect is superior to YF (air-cooled) coolers and traditional tube heat exchangers, which is 1-3 times that of tube heat exchangers, thus saving energy and having good economy.

2. Less heat loss

The oil cooler mechanism is compact, with a small footprint and exposed surface area. If the ambient temperature fluid flows from the outer edge channel to the center of the oil cooler, there is no need for insulation.

Before leaving the factory, although the transformer oil cooler is strictly inspected according to the professional standards of the enterprise, the two spiral channels are cleaned before conducting a pressure test. However, before on-site installation and testing, attention should still be paid to cleaning the two spiral channels, especially ensuring that there are no impurities or moisture in the transformer oil channel. Then, pressure test the oil channel with transformer oil and inspect the electrical strength of the oil sample. Only after all indicators are qualified can the oil cooler be connected to the transformer body. The connection between the oil cooler and the transformer is similar to that of a tubular heat exchanger: the oil is pumped out from the upper part of the transformer by an oil pump, enters the oil cooler, and then flows back to the transformer through the lower part of the oil tank. To monitor the safe circulation of the transformer, thermometers are installed at the inlet and outlet of the oil channel, and pressure gauges and oil flow relays are installed at the oil inlet. According to user requirements, thermometers and pressure gauges can be synchronously monitored on site and in the control room. Users can request them from the manufacturer as needed when placing orders.

Table 1 Reference Table for Selection of BLS6 Transformer Oil Cooler

Table 2 Basic Dimensional Reference Table for BLS6 Transformer Oil Cooler