Liquid Nitrogen Quick Freezing Cabinets DKN-LFC Series: How to Determine Racks, Trolleys and Zoning Structure (Four-Model Parameter Comparison)
Equipment Overview
The liquid nitrogen quick freezing cabinet is a cabinet-type batch operation device: materials are loaded into the cabinet in batches by rack or trolley, and after the door is closed, liquid nitrogen is sprayed in under program control for cooling; when the program ends, the door is opened and products are discharged. Compared with continuous tunnel lines, the difference of the cabinet type lies not in the cold source but in the loading unit — tunnels move materials continuously on mesh belts, while cabinet types organize loading and unloading by racks, trays and trolleys.
The cabinet body is the foundation of this type of equipment. The inner and outer chambers are formed by shearing, bending and welding SUS304 food-grade stainless steel plates; reinforcing ribs are added at load-bearing positions with PTFE reinforcement, so that deformation does not occur under heavy loads. The connection between inner and outer chambers uses ultra-low-temperature sealing rings customized according to Kunning Cryo processes, which do not harden at low temperatures and simultaneously absorb the displacement caused by inner chamber contraction, reducing stress at the connection. The bottom of the inner chamber is provided with load-bearing supports, considering both load capacity and insulation. The insulation layer uses a multi-layer adiabatic foaming process with a thickness of 150 mm. The protective tube of the temperature sensor is a SUS304 seamless tube, installed in the middle of the inner chamber wall, reflecting the actual temperature in the chamber and also preventing the thermocouple from being damaged by materials. The exhaust hole is located at the rear of the equipment, so condensed water does not drip onto the trays. The electrical control cabinet is embedded in the upper part of the cabinet body, taking up no additional floor space.
The liquid nitrogen path goes from an external storage tank through an insulated delivery pipe into the cabinet, passes through a flow control valve and is sprayed by a porous disperser; three sealed low-temperature-resistant motors are externally mounted, transmitting power into the cabinet through extended stainless steel shafts, with fully welded sealing flanges at the shaft holes; fans break up and gasify the liquid nitrogen, which impacts the material surface with the help of guide plates. Technical data records that the fan airflow field is designed through simulation, with a uniform air velocity of 10 m/s, and the air velocity can be adjusted by frequency conversion. The control part is PLC plus touch screen, with PID automatic adjustment, capable of ten-step operation for cooling and holding, automatic alarm and power-off at program end, and the temperature measuring element is a PT100 platinum resistor.
Industry-side requirements are converging toward process records. In the Xinhua News Agency article “Six Questions and Six Answers on the Draft National Standard for Prepared Dishes and Other Solicitation of Opinions” (February 9, 2026) reposted on the website of the State Administration for Market Regulation, the definition of prepared dishes includes “no added preservatives,” and the interviewed experts explained that the reason is that such products can usually be kept safe through physical means such as freezing, refrigeration, high-temperature sterilization and modified atmosphere packaging. The freezing process takes over part of the responsibility originally borne by additives, and the temperature curve and time records of the quick freezing stage become data that must be traceable. In addition, the “Central Kitchen Construction Requirements” (GB/T 44142-2024) and “Central Kitchen Operation Management Specifications” (GB/T 44141-2024) approved and issued by the State Administration for Market Regulation (Standardization Administration), put forward specific requirements for the facility and equipment configuration and processing process management of central kitchens, and quick freezing and cooling equipment is part of this.
Models and Parameters
Model naming: LFC corresponds to L (liquid nitrogen) + F (quick freezing) + C (cabinet), and the number is the capacity level (kg).
Public parameters of the four standard models:
| Item | DKN-LFC-300 | DKN-LFC-600 | DKN-LFC-1200 | DKN-LFC-1500 |
|---|---|---|---|---|
| Structure type | Cabinet type, manual door opening | Cabinet type, manual door opening | Cabinet type, side door opening, four zones | Cabinet type, two zones |
| Equipment inner chamber dimensions | 900 x 1320 x 1800 mm | Not marked in technical documents | 2000 x 1500 x 1750 mm (single zone) | 1300 x 1700 x 1800 mm (single zone) |
| Equipment outer dimensions | 1740 x 1730 x 2220 mm | 2900 x 1700 x 2450 mm | 8730 x 2350 x 2170 mm | 3800 x 2500 x 2300 mm |
| Common working temperature | -150℃ to room temperature | -150℃ to room temperature | -150℃ to room temperature | -150℃ to room temperature |
| Temperature control accuracy | ±1℃ | ±1℃ | ±2℃ | ±2℃ |
| Temperature uniformity | ±3℃ | ±3℃ | Not marked in technical documents | Not marked in technical documents |
| Cooling speed (no load) | Not less than 20℃/min, adjustable | Not less than 20℃/min, adjustable | Not more than 50℃/min, adjustable | Not more than 50℃/min, adjustable |
| Power supply specification | 380V (technical documents also record 52Hz) | 380V (technical documents also record 52Hz) | 380V wide voltage | 380V wide voltage |
| Overall power | 2.5 kW | 5 kW | 12 kW | 5 kW |
| Liquid nitrogen working pressure | 5~8 bar | 5~8 bar | 6~8 bar | 6~8 bar |
| Nominal quick freezing capacity | 300 kg/h | 600 kg/h | 0~1200 kg/single zone | 1500 kg/batch |
| Oxygen concentration detection | Not marked in technical documents | Not marked in technical documents | Set value 19.5%~21.5% | Set value 19.5%~21.5% |
Loading unit and rack/trolley configurations:
| Model | Rack | Tray and trolley | Loading description |
|---|---|---|---|
| DKN-LFC-300 | 1 unit, clear height 1600 x width 605 x depth 807 mm, standard layer height spacing 75 mm (can be designed according to product) | Tray 400 x 600 x 25 mm stainless steel (buyer self-provided); transfer trolley length 1050 x width 750 x height 873 mm | Can hold 40 trays at a time |
| DKN-LFC-600 | Rack configuration not marked in technical documents | Equipped with dedicated transfer push cart and trolley | Confirmed according to product specifications and buyer |
| DKN-LFC-1200 | 10 units, each depth 1300 x width 1500 x height 1470 mm, upper and lower two-layer structure | Loaded by zone, can be used with push-through trolley | Single zone 0~1200 kg, four zones can be set separately |
| DKN-LFC-1500 | Rack quantity not marked in technical documents | Equipped with dedicated transfer push cart and trolley | Two-zone structure, 1500 kg/batch |
The parameters in the above table are taken from Kunning Cryo liquid nitrogen quick freezing cabinet technical data and the official website liquid nitrogen quick freezing cabinet product page. Several notes:
- The basis for quick freezing capacity is not uniform: the technical documents for 300 and 600 use hourly basis (kg/h), 1200 uses single-zone loading capacity (kg), and 1500 uses per batch (kg/batch). The three bases cannot be directly converted between each other, and calculation should be based on your own materials, single tray specifications and one-time input quantity.
- For the power supply of 300 and 600, the technical documents record 380V/52Hz; verify against the actual on-site power supply before ordering; 1200 and 1500 are 380V wide voltage. For export to 60Hz regions, electrical components and motors must be re-selected and confirmed according to the order.
- Quick freezing capacity varies with product type and packaging method, and the technical data attaches this note to every capacity figure. Testing the freezing time once with your own materials before production is more prudent.
- Rack layer height spacing, number of trays per batch, and trolley type (including push-through type) are all adjusted according to product form, and tray dimensions are also a negotiable item.
- The inner chamber dimensions of 600 and the temperature uniformity of 1200 and 1500 are not given in the technical documents, and this page does not fill in numbers.
Main Configurations
Cabinet Body and Loading
- SUS304 food-grade stainless steel inner and outer chambers, reinforcing ribs with PTFE reinforcement at load-bearing positions
- Insulation layer thickness 150 mm, multi-layer adiabatic foaming
- Ultra-low-temperature sealing rings customized according to ultra-low-temperature working conditions; DKN-LFC-1200 additionally has elastic silicone strips between the door cover and cabinet body for heat insulation
- High-strength adiabatic supports at the bottom of the inner chamber, considering both load capacity and insulation under heavy-load conditions
- Integrated embedded electrical control cabinet, operation screen embedded in the upper part of the cabinet body
- Equipped with transfer push cart and trolley; trolley type can be changed to push-through type as needed, reducing workshop turnover floor space and personnel handling movements
Liquid Nitrogen and Circulation
- Liquid nitrogen flow control valve: low-temperature liquid nitrogen solenoid valve and liquid nitrogen proportional valve / pneumatic low-temperature valve are provided separately by model, and valve body diameter and interface are determined according to the technical agreement
- Liquid nitrogen is sprayed through a porous disperser, forcefully broken up and gasified by fans, and directly impacts materials
- Circulation motors are sealed low-temperature-resistant motors externally mounted, with extended stainless steel shafts passing into the cabinet, external fully welded sealing flanges, and air velocity adjustable by frequency conversion
- Circulation fans are low-temperature-resistant engineering plastic multi-blade axial flow fans, with hydrophobic surfaces that are not prone to frosting; the airflow field is designed through simulation, and technical data records a uniform air velocity of 10 m/s
- Liquid nitrogen delivery pipe is a low-temperature high-pressure pipe with outer insulation treatment
Control and Safety
- PLC intelligent control plus touch screen human-machine interface, PID automatic adjustment, capable of ten-step operation for cooling and holding, automatic alarm and power-off at program end
- PT100 platinum resistor temperature measurement, temperature measurement range 200℃ to -200℃; DKN-LFC-300 uses Class A elements, with the protective tube located in the middle of the inner chamber wall
- Touch screen supports manual and automatic operation, can store multiple freezing processes, one-button operation
- DKN-LFC-1200 and DKN-LFC-1500 are equipped with oxygen concentration detectors, set value 19.5%~21.5%, interlocked with the equipment
- Dual temperature sensors for main control and monitoring, over-temperature alarm; equipment has grounding wire, circuit breaker and phase sequence protector; DKN-LFC-1200 additionally has an emergency stop switch
Main configurations (system level):
| System / Component | Configuration points |
|---|---|
| Liquid nitrogen control valve | Low-temperature liquid nitrogen solenoid valve / proportional valve / pneumatic low-temperature valve, provided separately by model |
| PLC and temperature control module | Programmable controller with temperature control module, PID automatic adjustment, capable of ten-step operation |
| Touch screen | 7-inch human-machine interface (DKN-LFC-300), program storage and one-button operation |
| Temperature measuring element | PT100 platinum resistor, DKN-LFC-300 uses Class A elements |
| Electrical components | Circuit breaker, phase sequence protector, grounding protection complete set; DKN-LFC-1200 and DKN-LFC-1500 additionally have oxygen concentration interlock and emergency stop |
| Sealing strip | Ultra-low-temperature sealing strip, does not harden at low temperatures, absorbs inner chamber contraction displacement |
| Cabinet insulation | 150 mm multi-layer adiabatic foaming insulation layer |
| Circulation fan | Centrifugal / axial low-temperature circulation fan, air velocity adjustable by frequency conversion |
| Drive motor | Sealed low-temperature-resistant motor externally mounted, extended stainless steel shaft passing into the cabinet, fully welded sealing flange |
| Cabinet material | SUS304 food-grade stainless steel inner and outer chambers |
Application Scenarios
The following directions are listed according to industry application solutions; specific configurations are confirmed according to material testing and orders.
| Application direction | Typical materials | Loading and model approach |
|---|---|---|
| Prepared dishes and prepared food packs | Prepared meat products, semi-finished dishes, soup packs | Many product changeovers, loading by tray and basket; four-zone models can run different items simultaneously |
| Aquatic product processing | Shrimp, fish fillets, shellfish, fish heads | Thin materials can be frozen through in a few minutes according to technical data; tray spreading thickness should be uniform |
| Pastry and baking semi-finished products | Steamed buns, dumplings, dough, pastries | Loaded by tray, rack layer height spacing adjusted according to product height |
| Cooked food and braised products | Braised products, roasted meats, braised meats | Loading method determined by packaging form; bare and packaged materials have different thermal resistance |
| Central kitchen and group meals | Semi-finished products, portioned meals | In line with facility equipment and process management requirements, freezing records and temperature curves retained |
| Sample making and trial production | Small-batch new products, formula verification | 300 holds 40 trays at a time, convenient for small single batches and many batches |
Selection approach for the two types of equipment: for single items, continuous production scheduling, and stable hourly output, use the liquid nitrogen quick freezing tunnel and calculate by mesh belt width and length; for many varieties, small batches, and workshop turnover by trolley, use the cabinet type. If the process requires cooling high-temperature cooked food to 0~4℃ without freezing, the processing object is different; see food blast chiller. For how to choose between liquid nitrogen and compressor refrigeration, refer to comparison of liquid nitrogen quick freezing and mechanical refrigeration; for the capacity selection and parameter correspondence of the four models, see liquid nitrogen quick freezing cabinet selection.
Information to confirm for selection:
| Item | Description |
|---|---|
| Material form | Bare or packaged, single piece dimensions, single piece weight and thickness |
| Single tray and single basket specifications | Tray dimensions, single tray weight, whether buyer self-provides trays |
| One-time input quantity | By batch, or converted to hourly output |
| Inlet temperature and target temperature | Material inlet temperature and required core temperature to reach |
| Site and floor height | Equipment outer dimensions and door opening direction, trolley turnover and maintenance passages; 1200 model outer dimensions approximately 8.7 meters long |
| Liquid nitrogen supply | Storage tank self-provided by buyer, supply pressure according to model requirements |
| Power supply and system | Voltage, frequency, capacity; 60Hz regions require re-selection |
| Export region | Voltage system and certification requirements of target market |
To calculate the capacity level and rack configuration according to your products, describe the material type, single tray specifications, one-time input quantity, inlet temperature and target core temperature, and we will provide a solution according to actual needs: Contact us
Web sources:
- Xinhua News Agency article “Six Questions and Six Answers on the Draft National Standard for Prepared Dishes and Other Solicitation of Opinions” (February 9, 2026) reposted on the website of the State Administration for Market Regulation: https://www.samr.gov.cn/xw/mtjj/art/2026/art_4d42101809834b6f9e0ce9f06f1bcc90.html
- “Central Kitchen Construction Requirements” (GB/T 44142-2024) and “Central Kitchen Operation Management Specifications” (GB/T 44141-2024) approved and issued by the State Administration for Market Regulation (Standardization Administration), repost page: https://www.aks.gov.cn/zwgk/fdzdgknr/zdlyxxgk/scgzbzhjgzf/20251117/i1348035.html