NB/T 10418-2020Air-source heat pump dryer for grain (English PDF)

3.1 Air-source heat pump dryer for grain

The air source heat pump is used as the heat source to evaporate the moisture in the grain to reach the required moisture. It is also called the air source heat pump grain dryer.

3.2 Continuous flow dryer for grain

The grain passes through the dryer uninterruptedly and drops to the required moisture at a time without circulating drying equipment.

3.3 Recirculation dryer for grain

Drying equipment that performs multiple cycles of drying until the grain reaches the required moisture.

3.4 Throughput

The quality of the wet grain that requires moisture is reduced to the wet grain quality by one-time drying by a continuous dryer in a unit time.

3.5 Batch throughput

The quality of wet grain filled at one time according to the effective volume of the circulating dryer before drying.

3.6 Drying rate

The change value of grain moisture per unit time after repeated drying.

3.7 Specific moisture loss

The water lost per unit time in the process from the beginning of drying to the discharge of dry food.

3.8 Specific electric consumption

During the drying process, the total electricity consumed by the dryer, air source heat pump and auxiliary electric heating for every kilogram of water evaporated from the grain.

4.1 Classification

4.1.1 According to the type of dryer, it is divided into circulation type and continuous type.

4.1.2 According to the structure of the air source heat pump using air heat, it is divided into. closed, open and semi-open.

4.2 Coding

The product code structure of the dryer should comply with the regulations of JB/T 8574, and the meaning of each code position is shown in Figure 1.

Part 1 Part 2 Part 3 Part 4-Part 5 Part 6 5.Threshing, selection, Drying and storage machinery H. Grain dryer X-circular L-continuous R. Air source heat Example: 5HXR-30 means an air source heat pump circulating grain dryer with a batch capacity of 30t.

4.3 Main parameters

The main parameters and main parameter series of the dryer are shown in Table 2.

5.1 General requirements

5.1.1 The hot air duct of the dryer should be equipped with a hot air temperature monitoring device.

5.1.2 The air source heat pump unit matched with the dryer should meet the requirements of NB/T 10156.

5.1.3 The hot air temperature of the dryer and the allowable temperature of grain heating should meet the requirements in Table 3.

5.2 Performance Index

The performance indicators of the dryer should meet the requirements of Table 4.

5.3 Assembly quality

5.3.1 After the whole machine is assembled, the shape of the dryer should be free from scratches or misalignment; the inner surface should be smooth, without bosses or grooves; the base should be stable and flat.

Straight, no skew; the embedded parts should be well connected and no looseness.

5.3.2 Shafts, gears, pulleys and other rotating parts shall not show movement, bounce, deflection or vibration after assembly.

5.3.3 The grain discharge mechanism of the dryer should rotate flexibly, without jamming and scratching, and at the same time should ensure sufficient strength, and should not change during operation. shape.

5.3.4 The hot air pipe of the whole machine should be laid with an insulating layer, the surface should be flat and free of depressions, and the pipe should be airtight.

5.4 Appearance quality

5.4.1 There should be no rust and burrs on the outer surface of the dryer.

5.4.2 The surface of the electroplated parts should be smooth, uniform in color, and there should be no peeling or scratches.

5.5 Coating quality

5.5.1 There should be no obvious bubbles, flow marks, missing coating, primer leakage and damage on the painted surface.

5.5.2 The thickness of the surface paint coating should meet the requirements of JB/T 9832.2.

5.6 Electrical control

5.6.1 General requirements

5.6.1.1 The electrical control shall include the control of the dryer host, air source heat pump, in and out grain conveying and cleaning equipment, etc.

5.6.1.2 The air source heat pump can be controlled separately or integrated with the dryer host.

5.6.1.3 All electrical controls shall have the functions of overload, undervoltage, short circuit, open circuit and leakage protection.

5.6.2 Insulation

The equipment should have good insulation, and the insulation resistance between the live parts of the unit and the non-live parts that may be grounded should not be less than 2Mohm.

5.7 Effectiveness

The dryer is tested according to the method in 6.7. The dryer should not cause complete loss of machine functions, endanger work, personal safety, or cause damage.

Fatal failures caused by the scrapping of important assemblies, as well as serious failures that cause serious degradation of functions and damage to main components, the effectiveness of use should not be small At 98%.

5.8 Security

5.8.1 Security Protection

5.8.1.1 Reliable protective covers should be provided for exposed transmission and rotating parts that are dangerous to operators.

5.8.1.2 The platforms, corridors, ladders and towers should be equipped with handrails or fence protection facilities. The height of the fence (guard) should be >=1100 mm.

A retaining ring should be installed at a distance of more than 3000 mm from the ground.

5.8.1.3 Safety protection devices should be installed at the air inlets of all positive pressure fans of the continuous dryer.

5.8.1.4 Except for the mobile dryer, the top of the circulating dryer should have an upper cover, and a protective grid should be provided to prevent the operator from falling. column.

5.8.2 Safety information

5.8.2.1 Motor transmission devices, fan air inlets, high-temperature heat source devices and grain discharging chain transmission mechanisms that are or are potentially dangerous to the operator For other parts, permanent safety warning signs should be fixed at obvious locations nearby, and the safety signs should meet the requirements of GB 10396.

5.8.2.2 There should be safety precautions in the instruction manual, and the safety warning signs set on the product shall be reproduced in the instruction manual.

5.8.3 Safety equipment

5.8.3.1 The circulating dryer shall be equipped with a grain level observation hole or a material level display device, a full grain alarm device, a hot air temperature overtemperature alarm device and Warning device before starting; continuous dryer should have hot air temperature over-temperature warning device, warning device before starting, material level device or material level display monitoring Device.

5.8.3.2 The lower part of the continuous dryer should be equipped with emergency food outlets with quick-opening mechanism, and the emergency food outlets should be symmetrically distributed.

5.8.3.3 Drying units for outdoor operations shall be provided with lightning protection devices for air-termination, down conductors and grounding bodies. […]