Customization of Electric Heating High Temperature Drying Room Equipment

Working principle and system composition of electric high-temperature drying room

Electric heating high-temperature drying room is a drying equipment that works based on the principle of converting electrical energy into thermal energy. Its core is to convert electrical energy into thermal energy through electric heating elements, heat the air, and remove moisture from the material through forced convection. The working temperature range of this type of drying room is usually between 30 ℃ and 150 ℃, which is particularly suitable for the 40-80 ℃ temperature range commonly used in the processing of Chinese medicinal materials. It can meet the drying needs of the vast majority of medicinal materials without damaging the active ingredients.

The thermodynamic system of an electric drying room follows the basic principle of the air enthalpy humidity diagram. Fresh air enters the heating zone after filtration, and is heated to the set temperature by electric heating elements. The relative humidity decreases accordingly, forming hot air with strong moisture absorption ability. This hot air, driven by a circulating fan, evenly passes through the medicinal layer, absorbs moisture from the surface of the material, and becomes humid and hot air. Part of the humid and hot air is discharged from the system through the dehumidification valve, while an equal amount of fresh air is replenished to maintain an appropriate air pressure balance and oxygen content in the system. It is worth noting that high-quality electric drying rooms will be equipped with heat recovery devices to recover some sensible and latent heat during the dehumidification process, which can improve overall energy efficiency by 15-25%.

Customization of Electric Heating High Temperature Drying Room EquipmentThe electrical system is its core component, mainly including electric heating elements, temperature control instruments, electrical protection devices, etc. Electric heating elements are usually made of stainless steel electric heating tubes or PTC ceramic heaters. The former has lower cost and good high temperature resistance (up to 600 ℃), while the latter has automatic constant temperature characteristics and is safer. The temperature control system often adopts PID intelligent regulation technology, combined with SSR solid-state relays to achieve precise power modulation, and the temperature control accuracy can reach ± 0.5 ℃. In terms of electrical protection, multiple safety devices such as overcurrent protection, leakage protection, and phase sequence protection must be equipped to ensure the long-term reliable operation of the equipment.

In terms of structural composition, standard electric high-temperature drying rooms usually include seven major systems:

Thermal insulation box system: using polyurethane foam or rock wool sandwich panels with a thickness of 100-150mm, a heat transfer coefficient of less than 0.25W/(m ² · K), and inner and outer walls made of color steel plates or stainless steel plates

Heating system: Multiple sets of electric heating tubes (usually 3-6 sets) are arranged in zones, with power ranging from 12kW to 120kW, and can be started and stopped in stages

Hot air circulation system: High temperature resistant centrifugal fan (air volume 1000-10000m ³/h), combined with carefully designed air ducts to ensure uniform air speed

Dehumidification system: electric regulating valve combined with humidity sensor to automatically control the dehumidification volume

Control system: PLC or microcomputer controller, programmable multi segment curve control, with data recording function

Material rack system: made of stainless steel or aluminum alloy, with adjustable interlayer spacing and a load-bearing capacity of 30-50kg/m ²

Security system: multiple protections such as over temperature protection, fan fault alarm, electrical protection, etc

Technical parameters and performance characteristics of electric drying room

Customization of Electric Heating High Temperature Drying Room EquipmentThe technical parameters directly affect its drying efficiency and the quality of medicinal materials. Chinese herbal medicine processing enterprises must pay close attention to the following core indicators when purchasing:

The temperature control capability is the primary parameter for evaluating the performance of a drying room. A high-quality electric drying room should have:

Wide temperature range: 30-150 ℃ continuously adjustable, suitable for different medicinal needs

High control accuracy: temperature difference at each point inside the box is ≤± 1.5 ℃, and temperature fluctuation is ≤± 0.5 ℃

Quick response: The time required to rise from room temperature to 80 ℃ is ≤ 25 minutes (no load)

Multi stage programming: at least 10 temperature time curves can be set, supporting slope heating

The humidity regulation performance is equally critical, mainly including:

Humidity range: Relative humidity 10% -95% RH adjustable (humidification device required)

Dehumidification capacity: Unit time water evaporation rate 1-5kg/h · m ³ (depending on the model)

Humidity control accuracy: ± 3% RH (within the range of 40-80 ℃)

The electrical parameters determine the energy consumption and safety of the equipment:

Rated power: Small (12-36kW), Medium (36-72kW), Large (72-120kW)

Power requirement: 380V three-phase five wire system, voltage fluctuation range ± 10%

Insulation resistance: ≥ 100M Ω (cold state), ≥ 2M Ω (hot state)

Voltage resistance performance: 1500V/1min without breakdown

The structural performance parameters include:

Effective volume: ranging from 2m ³ to 50m ³, commonly used for 10-20m ³ in the processing of traditional Chinese medicinal materials

Load bearing capacity: drying rack 50-80kg per square meter (evenly distributed)

Wind speed: adjustable horizontal wind speed of 0.5-2.5m/s, vertical wind speed of 0.3-1.5m/s

Hot air circulation times: ≥ 30 times/h (ensuring uniform temperature field)

Electric hot drying rooms have significant advantages over other types of heat sources:

Accurate temperature control: high electric thermal conversion efficiency (≥ 95%), fast response speed, suitable for temperature sensitive traditional Chinese medicinal materials

Environmentally friendly: No burning waste gas pollution of medicinal herbs

Easy to operate: One click start, high degree of automation, reducing human operation errors

Flexible installation: No need for fuel storage space, only power supply, strong adaptability to the site

Safe and reliable: no open flames, no flammable or explosive risks, multiple electrical protections

However, there are also certain limitations:

High operating costs: dependence on electricity, poor economic viability in areas with high electricity prices

Limited heating speed: It takes a long time for a large capacity drying room to heat up from a cold state to working temperature

High power load: Large equipment requires dedicated transformers, and the initial investment in power transformation may be relatively high

Large thermal inertia: The cooling of the electric heating tube takes time, and the emergency cooling response is slow