## 1 Introduction  
Low-temperature storage is essential for aquatic products because the freshness rapidly decreases immediately after the catch. The decline of aquatic products relates not only to quality, but also to consumers' health, resulting in a large difference in the value of the product depending on the freshness [1]. In addition, in recent years, because of the enrichment of the public consciousness, there is a demand for fresher or even live catch [2; 3]. Therefore, to meet future demands, it is important to improve the quality of the catch rather than the quantity. However, it is difficult to install a suitable freezing device for each size of fishing vessel in Korea, because most of the fishing vessels are less than 30-100 tons [4]. Therefore, fishing and transport vessels are using crushed ice which is made of fresh water, and in a fishing area, the catches are mixed with the pre-loaded ice and stored in the fish storage hold. In this case, since crushed ice is used for the storage of the catch, there is a problem of osmotic pressure due to the difference in salt salinity with the catch, and can be damaging to the catch due to the large and sharp shapes of ice during storage and transportation. In addition, when mixed with seawater, ice is deposited at the top of the seawater due to the difference in density of seawater and ice, resulting in a temperature gradient in the storage. Due to the large shape of the crushed ice, air pockets occur when cooling small catches such as anchovies and shrimps, and the ice does not come in close contact with the catch, thereby interfering with the low-temperature maintenance of the catch. Because of the above reasons, using crushed freshwater ice has limitations in keeping the quality of the catch and maintaining the best quality of the catch. Therefore, there is a need for a new cooling method. The ice slurry shown in Figure 1 is a solid-liquid two-phase fluid in which small ice particles are mixed with water or a low-concentration aqueous solution and is called ice slurry, snow ice, flow ice, sherbet ice and so on. Since the size of the ice particles is as small as a few micrometers, the contact area with the object to be cooled can be increased; therefore the cooling rate is fast, and the ice particles are mixed with the liquid so that it can be easily transferred to the general pump and piping. It also contains the latent heat of ice, so it has more than 80 times the amount of cold capacity compared to the same amount of water. The temperature of the ice slurry has the same freezing point as the liquid, and therefore a lower temperature can be obtained from the ice slurry than that of the fresh water by controlling the concentration of the aqueous solution. As described above, the slurry type ice-making device has been studied since the late 1990s [5; 6; 7; 8]. Due to the advantages of the ice slurry, and the heat transfer characteristics of the ice-making device using brine without phase change, research on ice packing factor (IPF) measurement methods have been carried out. However, studies on the ice-making device with seawater for cooling of the catch and the performance characteristics of the ice-making device are insufficient. Traditional studies related to this study are as follows. First, [PERSON] et al. [9] experimentally investigated the effect of different parameters on heat transfer in SSHE (Scraped Surface Heat Exchanger) where freezing of the water/ethanol mixture and aqueous sucrose solution occurs. Ethanol solutions were used as a secondary refrigerant on the outside of the ice maker. The internal heat transfer coefficient has been found to have the greatest effect on the rotational speed of the wing included in the SSHE. [PERSON] et al. [10] showed the basic theory of ice slurry production and the practical use of two types of ice-makers, namely, scraped surface type and orbital rod type. The product was presented and reviewed.