Application of spiral plate heat exchanger in instant noodles cooking oil heating process

The Spiral Plate Heat Exchanger specially used for heating frying oil is a heat exchange device that uses steam as the thermal medium to heat edible oil. The edible oil absorbs heat energy through heat exchange to reach the frying temperature required by the production process. This heat exchange process is a typical steam condensation. The latent heat released by the condensation is absorbed by the edible oil on the other side. Macroscopically speaking, this process mainly provides heat by phase change during steam condensation. That is to say, the steam is on the entire length of the steam side. The temperature in the spiral channel is constant, while the medium temperature on the edible oil side continuously absorbs heat and increases along the entire length of the spiral channel until it reaches the outlet of the Spiral plate heat exchanger. Saturated steam heating fluid without phase change (edible oil) should belong to typical condenser operating conditions. Because during the process of saturated steam exothermic condensation and phase change into liquid, its specific volume, specific heat capacity, thermal conductivity, and medium viscosity all change significantly, and a large amount of latent heat is released at the same time. In terms of heat transfer coefficient, this process is better than that without phase change. The thermal coefficient must be large. When saturated steam condenses, the condensate forms a condensate film on the wall, which gradually thickens and then falls along the wall; or many semi-bead droplets are formed on the wall and gradually condense into larger droplets. The string drips down.

In view of the physical and chemical properties of the oil in the heating and frying process and the actual use over the years, the spiral Plate Heat Exchanger adopts an unequal channel structure, that is, the steam condensation side channel gap is 10mm, and the edible oil side channel gap is 18mm. In order to adapt to Based on the flow characteristics of the two media and the mechanism of the steam condensation process, the inlet and outlet directions of the spiral plate heat exchanger were designed to be improved. The design considerations for the channel gap are as follows: the steam side is mainly used for condensation of steam and the steam is relatively clean. The channel gap of 10mm already meets the process requirements. For the edible oil side, it is mainly considered that most manufacturers use palm oil and the dynamic viscosity of this oil There is a huge difference with the temperature change, and the resulting resistance drop range is wide. Furthermore, when the edible oil returns to the spiral plate heat exchanger, it may contain carbonized impurities such as frying debris, so the channel gap is designed to be 18mm. .

In terms of design and manufacturing quality, for spiral plate heat exchangers, the spiral plates are rolled by blanking the entire coiled plate. There are no splicing welds in the spiral body. The spiral body is rolled using a special return-point spiral core mold with a uniform inflection point arc. There is no stress concentration in the transition, and the unique rolling technology can effectively avoid various processing defects in the spiral body, thereby ensuring that the two-channel media does not have hidden dangers of internal leakage caused by processing and manufacturing.