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1 Introduction As a unit operation, drying is applied in a wide range of industries, and the materials encountered during the drying process are diverse in type and varying in properties. For dry materials, it is very important to select the most suitable drying equipment ； It is not only an important guarantee for obtaining satisfactory and qualified products, but it also has a direct impact on investment and energy consumption. When selecting a drying method, the following aspects need to be considered: the impact of the heating method (convection, conduction, radiation) on the drying process ； The influence of operating intensity and operating pressure on the drying process ； Final performance and quality requirements of the product ； Properties of the material to be dried ； Energy prices, and so on. However, for a specific material, when there is no existing experience in its processing or when traditional drying equipment needs to be modified or upgraded, the aforementioned analysis methods often fail to identify a suitable drying device. At this point, obtaining relevant data and information through experiments in order to determine the drying equipment suitable for that specific material remains an effective and viable method. This paper aims to discuss the selection tests for drying equipment for aluminum hydroxide dry gel filter cakes. 2 Experimental Objectives: As a carrier for catalysts, the dry gel filter cake (aluminum hydroxide) is required to have a large specific surface area and pore volume. The wet content of the material at the inlet is 80%, while it is required that the wet content at the outlet be ≤3%. Based on the properties of the material, the rotary flash dryer, twin-screw dryer, and tray continuous dryer provided by Gongda Equipment Co., Ltd. were selected for this experiment. At the same time, oven drying was used in the laboratory for comparative analysis. Rotary flash dryers have advantages such as the ability to dry wet materials in one step to produce uniformly sized, qualified products, high drying efficiency, continuous operation, and compact design; however, they suffer from issues like high energy consumption, a tendency to damage the crystal structure of the materials, and the need for numerous post-treatment devices. A conductive type disk continuous dryer is a dryer in which hollow drying disks of various sizes are arranged alternately one above the other. The disks remain fixed, while a central shaft is equipped with rake arms; each rake arm has several rake blades, and the shaft drives these rake arms and blades to rotate. The rake blades are arranged appropriately so that the material on the smaller drying trays moves from the center toward the outer edge of the tray, and then falls from the outer edge of the smaller tray to the next larger drying tray ； The materials on the large disk move from the outer edge toward the center of the disk, driven by the rake blades, and then fall from the center to the next smaller drying disk. Through such repeated up and down movements, the finished product is ultimately discharged from the lowest tray via the discharge port. The dry moisture is discharged through the top outlet. This dryer features high thermal efficiency, low energy consumption, good controllability, and minimal material loss. The paddle dryer is also a type of conductive drying equipment, and its main advantage is high thermal efficiency. Objectives of this experiment: (1) To dry the gelatinous filter cake using a rotary flash dryer, a paddle dryer, and a tray continuous dryer, in order to verify whether the physicochemical properties of the dried product meet the process requirements. ⑵ The experimental results of the above three drying devices were compared and analyzed with those from the oven experiments. ⑶ An economic analysis of three types of drying equipment is conducted based on the requirements for production capacity. 3 Experimental Results and Analysis The equipment provided by Gongda Chemical Engineering Equipment Co., Ltd. includes a rotary flash dryer with dimensions of φ400mm×1500mm, a paddle dryer with a heat transfer area of 2.5 m2, and a φ800/6C disc-type continuous dryer. Two batches of dry gel (aluminum hydroxide) were used in the experiment, with a moisture content of 75%–80%. Separate drying experiments were conducted using three types of drying equipment as well as an oven; the experimental results are shown in Table 1. For alumina, which serves as a catalyst carrier, important technical parameters include pore volume and specific surface area. Based on these experimental results, the following conclusions can be drawn: (1) As a drying device for gelatinous substances, the tray-type continuous dryer enables the dried products to meet all the relevant technical requirements regarding pore volume, specific surface area, and moisture content, while also offering high thermal efficiency and low energy consumption. ⑵ The technical specifications of the products dried by the paddle dryer and the rotary flash dryer do not meet the required standards. In the drying process of paddle dryers, the material is compressed, which reduces its pore volume. ⑶ Due to the low density of alumina, it places higher demands on the subsequent separation equipment in rotary flash drying. Otherwise, as seen in the experiments, the yield of the product is low, with losses around 10%. ⑷ In terms of power consumption, disk-type continuous dryers have very low power consumption, while the other two drying methods require more power, which increases the cost of the products. In summary, for the dried products obtained through rotary flash evaporation and paddle drying, their key technical parameters—pore volume and specific surface area—are below the required levels, and the dried gel exhibits certain signs of aging. Therefore, these two types of dryers are not suitable as production equipment for drying glue. The dry glue products dried by the disc-type continuous dryer meet and even exceed the relevant technical specifications; moreover, it features high thermal efficiency and low energy consumption, making it an ideal device for drying glue. Based on the experiments, we decided to use the disc-type continuous dryer produced by Gongda Chemical Engineering Equipment Co., Ltd. as the drying equipment for the glue. 4 Production details: The material is aluminum hydroxide with a moisture content of 75%; the drying medium is saturated steam at 0.35 MPa. The initial temperature of the material is 20°C, and the required moisture content of the dried product is ≤5%. The output rate of the finished product is 80 kg/h. Calculations show that the water evaporation rate during the drying process is 224 kg/h, the required heat amount is 5.28×105 kJ/h, and the drying area required for a disk-type continuous dryer is 38.1 m2. Based on this, a disc-type continuous dryer model GDPG2200/14B manufactured by Shijiazhuang Gongda Chemical Equipment Co., Ltd. was selected, with a material of 304 stainless steel. The actual drying area of this device is 43.1 m2; it has 14 drying trays. The motor power is only 5.5 kW, the spindle speed ranges from 1 to 9 r/min, and the device occupies an area of 10 m2. Its price is 457,000 yuan. When including the auxiliary equipment, namely a dosing feeder and a crusher, the total cost comes to 483,000 yuan. The energy cost for producing 80 kg/h of aluminum hydroxide is as follows: 3640 kg of steam is required per ton of product, with a steam cost of 218 yuan per ton of product ； Installed capacity: 9.9 kW (including 2.2 kW for the dosing feeder and 2.2 kW for the crusher) ； Electric power consumption: 99 kW·h per ton of product; electricity cost: 54 yuan per ton of product ； The total energy consumption cost is 272 yuan per ton of product. (Note: The electricity cost is 0.55 yuan/kW·h, and the steam cost is 60 yuan/t.) This equipment operates well during production, is easy to operate, and its product parameters meet the relevant technical requirements. During drying, the material enters from the upper part of the equipment, while the product is discharged from the lower part. The air humidity inside the equipment is higher at the top and lower at the bottom. The dried exhaust gas is released from the upper part of the equipment, with a flow rate of approximately 0.2 m/s. The dust from the material does not get carried away with the exhaust gas, so there is no environmental pollution, and product loss is minimal. The thermal efficiency of this device is over 60%. Production practice has proven that the results obtained through experiments for selecting drying equipment were correct, yielding significant economic benefits.