Liquid Nitrogen Quick-Freezing Tunnel DKN-LFT Series: Parameters and Configurations of Four Models 0908/1206/1212/1612
Equipment Overview
The liquid nitrogen quick-freezing tunnel is a mesh belt continuous production line: materials are laid on the stainless steel mesh belt from the feed end, travel through the tunnel with the mesh belt to complete freezing, and then are output from the discharge end. The process requires no manual turning. The two dimensions of tunnel length and mesh belt width determine how much output a line can handle; the conveying speed determines how long materials stay in the low-temperature zone.
The equipment uses the superposition of liquid nitrogen vaporization heat absorption (latent heat) and low-temperature nitrogen gas warming (sensible heat) for heat exchange and cooling. The working temperature is -150℃ to room temperature. Liquid nitrogen injection devices are installed both above and below the material conveyor belt. The complete machine consists of the body, conveying system, refrigeration system, and control system. The body is an integral lift-type structure; when raised, the mesh belt and inner cavity can be cleaned.
Regarding how “quick-freezing” is determined, the regulatory authority’s response is: place pre-treated food in a device at -30℃～-40℃, pass through the ice crystal formation zone within 30 minutes, with the center temperature dropping from -1℃ to -5℃, forming ice crystals with a diameter of less than 100μmm, and after quick-freezing the food center temperature must reach below -18℃ (Shenzhen Municipal Market Supervisory Authority, 2024-11-20~B.
Regarding downstream demand, the East Money Data Center “2026 China Quick-Frozen Food Industry Report” (Qince Consumer Research, 2026-02-10) mentions that the acceleration of chain restaurant standardization is driving the expansion of the B-end market for quick-frozen food. The common characteristic of such customers is fixed single-product specifications and continuous production scheduling. When selecting a tunnel line, hourly output can be calculated based on fixed product items.
Web sources:
- Shenzhen Municipal Market Supervisory Authority https://www.sz.gov.cn/hdjlpt/detail?pid=3036296&via=pc
- East Money Data Center https://data.eastmoney.com/report/zw_industry.jshtml?infocode=AP202602101819861841
Models and Parameters
The public parameters of the four models are as follows:
| Item | DKN-LFT-0908 | DKN-LFT-1206 | DKN-LFT-1212 | DKN-LFT-1612 |
|---|---|---|---|---|
| Tunnel mesh belt dimensions | 8000 × 900 mm | 6000 × 1200 mm | 12000 × 1200 mm | 12000 × 1600 mm |
| Equipment external dimensions | 8000 × 1750 × 1670 mm | 6000 × 2200 × 1750 mm | 12000 × 2250 × 1670 mm | 12000 × 2700 × 1950 mm |
| Working temperature | -150℃ to room temperature | -150℃ to room temperature | -150℃ to room temperature | -150℃ to room temperature |
| Temperature control accuracy | ±2℃ | ±2℃ | ±2℃ | ±2℃ |
| Cooling rate (no load) | Approx. 10℃/min, adjustable | Approx. 10℃/min, adjustable | Approx. 10℃/min, adjustable | Approx. 10℃/min, adjustable |
| Power supply specification | 380V/50Hz | 380V/50Hz | 380V/50Hz | 380V/50Hz |
| Total power | Approx. 15 kW | 9 kW | 18 kW | 26 kW |
| Oxygen concentration detection | Set value 19.5%～21.5% | Set value 19.5%～21.5% | Set value 19.5%～21.5% | Set value 19.5%～21.5% |
| Liquid nitrogen working pressure | 5～8 bar | 5～8 bar | 5～8 bar | 0.5～0.8 MPa |
| Feed end to discharge end cycle | Not specified in technical data | 6～30 min adjustable | 5～25 min adjustable | 8～40 min adjustable, customizable |
| Nominal freezing capacity | Not specified in technical data | Not specified in technical data | 1 m³/hour | Approx. 1000 kg/h, varies with product and packaging method |
The parameters in the above table are from the Kunning Cryo liquid nitrogen quick-freezing tunnel technical parameter documents and the official website liquid nitrogen quick-freezing tunnel product page. Several notes:
- Mesh belt width, tunnel length and conveying speed can be designed according to product form and capacity requirements. The above table shows the dimensions of four standard models.
- Nominal freezing capacity varies with product type, single-package specifications and packaging method. Conduct actual testing with your own materials before production. The technical data for DKN-LFT-0908 and DKN-LFT-1206 only provides mesh belt dimensions and power, without nominal freezing capacity values, hence written as “not specified in technical data~R.
- Tunnel length and freezing time should be considered together. On the same line, the residence time of products in the tunnel is determined by the mesh belt speed; the longer the freezing time required by the process, the slower the mesh belt runs, and the longer the tunnel occupied for the same capacity.
- Thin-slice products have short freezing times. The technical data for DKN-LFT-1206 records that thin products can complete freezing within 1 minute; tray-loaded block and paste materials need to reconfirm the time based on actual thickness.
The technical data also contains a set of field application records for DKN-LFT-1212 (material is extract liquid tray products~B:
| Item | Parameter |
|---|---|
| Tray dimensions | 300 × 30 × 30 mm |
| Single batch freezing capacity | 6 m³ / 6 hours |
| Inlet temperature and target | 50℃ → center temperature -50℃ |
| Freezing time | Approx. 30 minutes |
| Tunnel length | 12 meters |
Main Configurations
Body and Insulation
- Inner and outer cavities are formed by shearing, bending and double-side welding of SUS304 food-grade stainless steel plates, with full welding of the inner cavity, no sanitary dead corners
- SUS304 stainless steel square tube reinforcement ribs added at stress points, reinforcement ribs treated with low-temperature foaming to reduce cold air penetration
- Insulation layer adopts multi-layer adiabatic foaming structure, thickness 150 mm
- Sealing strips customized with imported raw materials
- Lifting system is mechanical structure, motor plus worm gear transmission, with automatic locking device and manual safety bolt, lifting stroke 550 mm, inner cavity 750 mm, convenient for parts replacement and maintenance
- Bottom of the body has a shallow V-shaped design with drainage outlet, discharging cleaning waste and accumulated water
- Integrated electrical cabinet located on the right side of the feed inlet
Conveying System
- Conveyor belt is imported high-elasticity SUS304 stainless steel mesh belt, equipped with adaptive tensioning device, maintaining running tension at low temperatures
- Transmission power is variable-frequency motor plus reducer, mesh belt speed adjustable according to products
Refrigeration System
- Cooling system supports both manual and automatic liquid nitrogen modes
- Liquid nitrogen injection devices installed both above and below the conveyor belt, can be operated automatically or manually, can all be opened, or a single group can be opened individually; upper and lower injection angles are adjustable
- Top of equipment equipped with low-temperature explosion-proof moisture-proof fully-sealed long-shaft motor and axial flow fan, fan blades do not frost at low temperatures, each group of fans has a fixed angle, balancing convective heat exchange and temperature field uniformity
- Tail gas extraction ports at feed end and discharge end, connected to high-flow exhaust fan; exhaust fan interlocked with equipment, equipment does not run if exhaust fan is not started
Control System and Safety
- PLC intelligent control, touch screen human-machine interface, with PID automatic adjustment, can store multiple freezing processes, one-key operation
- PT100 platinum resistance temperature measurement, Class A, temperature measurement range 200℃～-200℃, one main control, one monitoring
- Emergency stop switches at discharge end, electrical cabinet and receiving end
- Oxygen concentration alarm interlocked with liquid nitrogen valve: when oxygen concentration is below the set value, close the on-off valve, equipment stops running, exhaust fan continues running, with audible and visual alarm
- Equipment has grounding wire, circuit breaker and phase sequence protector
Comparison of main component configurations of the four models:
| Name | Configuration |
|---|---|
| Liquid nitrogen flow control valve | DKN-LFT-1206 uses imported low-temperature proportional valve, dual-valve control; DKN-LFT-1612 uses imported pneumatic liquid nitrogen low-temperature valve; DKN-LFT-0908 and DKN-LFT-1212 use imported solenoid valve multi-channel control. All models equipped with manual liquid nitrogen shut-off valve |
| PLC and temperature control module | Industrial-grade PLC and temperature control module |
| Touch screen | Industrial touch screen (DKN-LFT-1206/1212 7 inch; DKN-LFT-1612 10 inch) |
| Platinum resistance | Heraeus |
| Electrical components | Industrial-grade low-voltage electrical components |
| Cabinet insulation material | Polyester polyol foaming insulation material |
| Sealing strip | Dow Corning |
| Cabinet material | SUS304 |
| Moisture-proof explosion-proof low-temperature resistant motor | Moisture-proof explosion-proof low-temperature resistant motor (DKN-LFT-0908/1212 and DKN-LFT-1206/1612 selected separately) |
| Screw lifting system | Specially customized |
Application Scenarios
| Industry | Typical materials | Model adaptation approach |
|---|---|---|
| Aquatic processing | Shrimp, fish fillets, fish heads, shellfish | Single-product continuous discharge, select mesh belt width between 1206 and 1612 based on hourly output |
| Meat and poultry processing | Cut meat, poultry cuts | Stable single-package specifications, determine tunnel length based on single-package weight and required freezing time |
| Prepared dishes and central kitchens | Prepared packages, dish semi-finished products, pastries | Frequent product switching, use variable-frequency speed control to match the rhythm of different items, calculate based on single-item production scheduling |
| Fruits and vegetables | Bamboo shoots, fruit and vegetable materials, berries | Consider mesh belt material spreading thickness, use grouped opening/closing of injection devices to control cooling distribution |
| Liquid extracts, paste tray products | Tray-filled materials | Long freezing time, suitable for long tunnels, refer to the field records of DKN-LFT-1212 in the above table |
If a single batch is only a few hundred kilograms with many varieties and small batches, cabinet-type equipment is more flexible, see liquid nitrogen quick-freezing cabinet; if what you need is atmospheric cold air circulation cooling for high-temperature cooked food down to 0～4℃, the processing object is different from the tunnel, see food blast chiller.
Installation Conditions
- The wiring between the main power line and the electrical control cabinet is to be installed by the buyer, power distribution designed according to 380V/50Hz
- Liquid nitrogen and liquid nitrogen storage tank are to be provided by the buyer, pressure supplied according to model requirements
- Exhaust duct is to be provided by the buyer, tail gas extraction ports at feed and discharge ends need to be connected to exhaust fan
- The tunnel is a continuous production line, operating and conveying connection space needs to be reserved at both feed and discharge ends
To verify tunnel model and capacity for your products, describe the material type, single-package specifications, hourly throughput and target center temperature, and we will provide a solution based on line configuration: Contact Us
Image requirements: liquid nitrogen quick-freezing tunnel complete machine appearance, feed and discharge ends and stainless steel mesh belt details, injection devices inside the tunnel and top axial flow fan photos.
Frequently Asked Questions
How much do the mesh belt dimensions of DKN-LFT-1206 and DKN-LFT-1612 differ?
The two specifications are different: the tunnel mesh belt dimensions of DKN-LFT-1206 are 6000 × 1200 mm, and DKN-LFT-1612 is 12000 × 1600 mm. Both belt width and length are not in the same tier. In terms of freezing capacity, the nominal value of 1612 is approximately 1000 kg/h, while 1206 is not specified in the technical data and needs actual testing with your materials before production.
What temperature can the liquid nitrogen quick-freezing tunnel reach, and what is the temperature control accuracy?
The working temperature is -150℃ to room temperature, temperature control accuracy ±2℃, no-load cooling rate approximately 10℃/min, adjustable. Liquid nitrogen working pressure is 5～8 bar or 0.5～0.8 MPa depending on the model, power supply is 380V/50Hz.
For DKN-LFT-1212 used for tray-filled liquid extracts, what is the freezing time recorded on site?
In the technical data, DKN-LFT-1212 has a set of field records: the material is extract liquid tray products, tray dimensions 300 × 30 × 30 mm, inlet temperature 50℃, to center temperature -50℃, freezing time approximately 30 minutes, tunnel length 12 meters, single batch freezing capacity 6 m³ / 6 hours.