Quality Rotary Dryer & Small Rotary Dryer factory

Overview of Small Drum Dryer A Small-scale Rotary Drum Dryer refers to a compact continuous drying equipment with a processing capacity usually ranging from 0.5 to 5 tons per hour. Its diameter is generally less than 2 meters and the length does not exceed 10 meters. Compared with large industrial drum dryers, small equipment has unique features in structural design, heat source selection and control systems. According to the definition in "Modern Agricultural Equipment" (2022), small drum dryers have become an important drying solution for small and medium-sized agricultural product processing enterprises, family farms and research institutions.   Structural features of small drum dryers The typical structure of a small drum dryer includes: Rotating roller system: Diameter 0.8-1.5m, length 3-8m, made of 304 stainless steel or carbon steel Heat source device: Adaptable to various fuels (electricity, gas, biomass, etc.) Transmission system: Driven by a variable frequency motor, with adjustable speed ranging from 2 to 8rpm Support structure: Modular design, convenient for installation and transportation Control system: Integrates temperature and humidity monitoring and automatic adjustment functions Research shows (Chen et al., Drying Technology, 2021) that the thermal efficiency of modern small-scale drum dryers can reach 65-75%, approaching the performance level of large-scale equipment.   Energy utilization efficiency   Quality assurance of drying The small drum dryer has unique advantages in product quality control: Good uniformity: The materials are thoroughly flipped, and the drying uniformity reaches over 95% Precise temperature control: PID control is adopted, with temperature fluctuation within ±2℃ Strong adaptability: It can handle various materials such as granular, flaky and fibrous ones Economy and return on investment The economic advantages of small-scale equipment are obvious: Low initial investment: approximately 1/3 to 1/5 of that for large-scale equipment Controllable operating costs: Suitable for intermittent production Easy maintenance: The repair cost is lower than that of large equipment   Typical applications of small drum dryers Agricultural Product Processing Grain drying: rice, corn, wheat, etc Processing capacity: 1-3 tons per hour Precipitation rate: 1-1.5% per hour Cash crops: tea, coffee beans, Chinese medicinal materials, etc Temperature control: 40-80℃ Special requirements: Color retention and aroma retention Preparation of Biomass Fuel Wood chip drying: The moisture content is reduced from 40% to 10-15% Straw processing: Provides qualified raw materials for subsequent shaping and preparation Drying of biogas residue: Realizing the resource utilization of organic waste   Small drum dryers, with their advantages in space adaptability, energy efficiency and drying quality, have become the ideal choice for medium and small-scale drying operations. It is particularly recommended that the following situations be given priority Small and medium-sized agricultural product processing enterprises Seasonal production demand Multi-variety and small-batch production Mobile drying operation scene Selection suggestion Determine the equipment parameters based on the characteristics of the materials Give priority to models with high energy efficiency Pay attention to the intelligent control function Attach great importance to after-sales service guarantee

1. Drying Box Technology Overview A drying box (also known as a drying oven or chamber) is a static drying device widely used in industrial, agricultural, and laboratory fields. Unlike continuous drying equipment (such as drum dryers), a drying box employs a batch processing method, where the drying process is achieved by controlling the temperature, humidity, and airflow inside the chamber. According to the definition in Drying Equipment Design and Application (Chemical Industry Press, 2020), a drying box mainly consists of the chamber structure, heating system, airflow circulation device, temperature and humidity control system, and moisture exhaust system.   2. The core advantages of the drying oven 2.1 Precise temperature and humidity control The most notable advantage of the drying oven lies in its precise temperature and humidity control capability. Research shows (Zhang et al., Journal of Food Engineering, 2021) : The temperature control accuracy can reach ±0.5℃ (laboratory grade). The relative humidity control range is adjustable from 5% to 95% The uniformity deviation of the temperature field is less than ±2℃ (within the effective working area) This precise control is particularly suitable for heat-sensitive materials, such as: Pharmaceutical raw materials (retention rate of active ingredients increased by 15-20% High-value agricultural products (such as dried precious Chinese medicinal materials) Precision electronic components (to avoid thermal deformation) 2.2 Adaptability to small batch and multiple varieties Compared with continuous drying equipment, drying ovens have obvious advantages in small-batch and multi-variety production scenarios: Quick production change: Changing materials only requires simple cleaning and no equipment modification Flexible parameters: Exclusive drying curves can be set for different materials Quality control: Each batch can be independently monitored and adjusted Food industry research shows (Wang et al., Drying Technology, 2022) that in multi-variety and small-batch production, the overall efficiency of drying ovens is 30-40% higher than that of continuous drying equipment.   2.3 Lower initial investment cost   Drying ovens hold an irreplaceable position in multiple fields due to their advantages of precise control, flexible adaptability and small-batch processing. It is recommended to give priority to choosing a drying oven in the following situations: Research and development and small-scale production scenarios Handling of high-value or heat-sensitive materials Special environmental requirements (sterile, explosion-proof, etc.)

Analysis of the Working Principle and Energy-saving Heat Source of Industrial Drum Dryer 1. Overview of Industrial Drum Dryer The industrial drum dryer is a continuous drying equipment widely used in fields such as grain, chemical engineering, minerals, and feed. Its core structure includes a rotating drum, a heating system, a feeding/discharging device, an exhaust gas treatment system, etc. It achieves efficient dehydration through direct or indirect contact between hot air and materials. According to the "Drying Equipment Design Manual" (Chemical Industry Press, 2018), drum dryers account for more than 30% of the industrial drying equipment market, and are particularly suitable for processing materials with high moisture content and large quantities. 2. Working Principle of Drum dryer (1) Basic workflow Feeding: Wet materials are evenly fed into the drum by a screw conveyor or belt conveyor. Hot air contact: High-temperature hot air (directly or indirectly heated) comes into contact with the material in the drum in countercurrent or co-current flow, and water evaporates. Rolling drying: The drum rotates at a low speed of 2 to 8 rpm. The built-in lifting plates keep the materials constantly turning over to ensure uniform heating. Exhaust gas discharge: Wet exhaust gas is discharged after passing through a cyclone separator or bag filter. Some systems adopt waste heat recovery. Discharge: The dried material is discharged from the end of the drum, with a moisture content of up to 12% to 15% (depending on the material). (2) Hot air flow mode Co-current type: Hot air flows in the same direction as the material, suitable for heat-sensitive materials (such as food and medicine), avoiding local overheating. Counter-flow type: The hot air flows in the opposite direction to the material, resulting in higher drying efficiency and being suitable for high-moisture materials (such as slag and sludge). Cross-flow type: Hot air passes perpendicularly through the material layer, with lower energy consumption but slightly poorer uniformity (reference: Mujumdar, Handbook of Industrial Drying, 2014).   3. Heat source selection and energy-saving analysis The heat source of an industrial dryer directly affects the operating cost and drying efficiency. According to the data from the China Energy Research Society (2022), the energy consumption comparison of different heat sources is as follows:   Heat source type Heat efficiency Unit cost (CNY/Ton) Applicable scenarios Coal consumption 60% - 70% 25-35 Traditional industry, high pollution risk Natural gas  75% - 85% 40-50 Food, medicine, high environmental protection requirements Biomass pellets 70% - 80% 30-40 agricultural by-products, carbon neutrality trend Heat pump (electricity) 300% - 400% 20-30 low-temperature drying (

The heating method of the grain dryer directly affects the drying efficiency, energy consumption and grain quality. According to domestic and international research, there are significant differences between direct heating and indirect heating in terms of heat source utilization, pollutant control, and grain quality maintenance.   (1) Direct Heating Principle: The high-temperature flue gas after the combustion of fuel (such as coal, diesel, biomass) is directly mixed into the dry hot air and comes into contact with wet grains. Structure: The combustion chamber is directly connected to the drying chamber without any heat exchange medium. Literature support Li Baofa et al. (Agricultural Machinery, 2016) pointed out that direct heating has a simple structure, but the flue gas contains sulfides, CO, etc., which may contaminate grains. Experiments conducted by the United States Department of Agriculture (USDA, 2020) show that when corn is directly heated and dried with coal, the residual SO₂ in the flue gas can reach 12 to 15 mg/m³.   (2) Indirect Heating Principle: The heat generated by combustion is transferred to clean air through a heat exchanger (such as finned tube or plate heat exchanger), and then sent into the drying chamber, where the flue gas is completely isolated from the grain. Structure: The combustion chamber is separated from the drying chamber and relies on a heat exchanger for heat transfer. Literature support Zhang Quanguo (Optimization of Agricultural Product Drying Process, 2019) pointed out that the hot air from indirect heating is pure and suitable for high-value-added grains (such as seeds and organic food). The FAO (2022) report indicates that indirect heating can reduce the contact of flue gas pollutants with food by over 90%.   Our current mobile grain dryer adopts indirect heating technology. Through a heat exchanger, clean hot air is brought into contact with wet grains, avoiding the contamination of grains by combustion exhaust gases while preserving the quality of the grains. The equipment is usually integrated into trailer or container structures, facilitating transportation to fields, grain depots or cooperatives, enabling immediate use upon shutdown and significantly reducing the loss caused by grain mold. The advantages of indirect heating (Based on professional literature and data) Food security and pollution-free Indirect heating sends pure hot air into the drying chamber through a hot blast stove or steam heat exchanger. Compared with direct combustion heating, it avoids the adhesion of harmful substances such as sulfides and carbon monoxide in the flue gas to the grains (Li Shaokun et al., "Corn Drying Technology", 2018). Studies have shown that when directly heating and drying rice, the contact of flue gas causes the fatty acid value to increase by 15% to 20%, while indirect heating does not have this problem (Transactions of the Chinese Society of Agricultural Engineering, 2020). High thermal efficiency and low energy consumption Indirect systems can reuse the dehumidified heat through waste heat recovery design. Experimental data show that indirect dryers using multi-stage heat exchangers are 20% to 30% more energy-efficient than traditional coal-fired direct dryers, with a thermal efficiency of over 75% (Zhang Quanguo, "Optimization of Agricultural Product Drying Processes", 2019). Precise temperature control ensures quality Indirect heating allows for precise adjustment of the hot air temperature (with an error of ±2℃), preventing high temperatures from causing grains to burst or proteins to denature. For instance, when drying soybeans, indirect heating can keep the rate of bulging at less than 3%, while direct heating can reach 8% to 12% (USDA ARS Report, 2021). Adapt to multiple fuels Indirect heat sources can use natural gas, diesel, biomass pellets, etc., to avoid the influence of fuel impurities on grains. The case shows that the carbon emissions of biomass indirect heating dryers are 40% lower than those of coal-fired direct dryers (FAO, 2022). Key data reference Drying efficiency: Processing capacity 5- 50 tons per day, moisture reduction rate 0.8% - 1.5% per hour (GB/T 21015-2007). Economic efficiency: The payback period for mobile indirect dryers is approximately 2 to 3 years (field measurement data, Henan Agricultural Machinery Research Institute, 2023).