Low-Temperature Freezer
1. Product Overview
1.1 General Description
A freezer is a refrigeration unit that provides a low-temperature cooling source. Through the evaporation, heat absorption and condensation, heat rejection cycle of the refrigerant, it cools the target object down to the -5℃ to -80℃ range. The freezer works on a vapour-compression refrigeration cycle and consists of four main components: compressor, condenser, evaporator and expansion valve. By evaporating temperature it is divided into medium-temperature (-5~5℃), low-temperature (-25~-5℃) and ultra-low-temperature (-80~-25℃) types. It is widely used for chemical reaction cooling, pharmaceutical freeze-drying, food quick-freezing and fresh-keeping, laboratory low-temperature environments and similar applications.
1.2 Key Features
- Wide refrigeration temperature range from -80~5℃
- Refrigerant options such as R22/R404A/R23
- Air-cooled / water-cooled condenser options
- Scroll / reciprocating / screw compressor options
- PID precise temperature control ±1℃
- Multiple safety protection systems
- Corrosion-resistant stainless steel evaporator
- PLC + touch screen control
1.3 Document Scope
This specification covers the design principles, performance parameters, system classification, key component selection, application fields, design standards and certifications, custom optional configurations, warranty terms, packaging and delivery of the freezer, together with the information required for an inquiry. It serves as a comprehensive reference for procurement, model selection and technical communication.
2. Working Principle
2.1 Freezer Process Flow
Freezer working cycle: the compressor draws in low-temperature, low-pressure refrigerant gas → compresses it into high-temperature, high-pressure gas → the condenser cools it into high-pressure liquid → throttled and depressurised by the expansion valve → evaporates in the evaporator, absorbing heat → the refrigerant becomes low-temperature, low-pressure gas → drawn back into the compressor to repeat the cycle. In the evaporator the refrigerant evaporates and absorbs heat from the cooled medium, lowering its temperature; in the condenser it condenses and releases heat to the environment. Cooling capacity is controlled via the expansion valve opening, while PID control achieves precise temperature regulation.
3. System Classification
| | | | |
|---|
| Medium-temperature type | LD-5, LD-10, LD-20 | Evaporating temp. -5~5℃ | Process cooling | Scroll compressor |
| Low-temperature type | LDL-25, LDL-40, LDL-60 | Evaporating temp. -25~-5℃ | Freezing / cold storage | Reciprocating / screw compressors |
| Ultra-low-temperature type | LC-80, LC-100 | Evaporating temp. -80~-25℃ | Cryogenic / freeze-drying | Cascade refrigeration |
4. Technical Parameters
4.1 Main Technical Parameters of the Freezer
| LD-5 | LD-10 | LDL-25 | LDL-40 | LDL-60 | LC-80 |
|---|
| Cooling capacity (kW) | 5 | 10 | 8 | 6 | 4 | 3 |
| Evaporating temp. (℃) | -5 | -5 | -25 | -40 | -60 | -80 |
| Condensing method | Air/Water | Air/Water | Air/Water | Water-cooled | Water-cooled | Water-cooled |
| Compressor type | Scroll | Scroll | Reciprocating | Recip./Screw | Screw | Cascade |
| Refrigerant | R22/R404A | R22/R404A | R404A | R404A/R23 | R23/R14 | R14/R50 |
| Temp. control accuracy | ±1 | ±1 | ±1 | ±1.5 | ±2 | ±2 |
| Power supply | 380V/50Hz | 380V/50Hz | 380V/50Hz | 380V/50Hz | 380V/50Hz | 380V/50Hz |
4.2 Dimensions and Weight
| | | | | |
|---|
| LD-5 | 800 | 600 | 1000 | 120 | 0.5 |
| LD-10 | 1000 | 700 | 1200 | 200 | 0.7 |
| LDL-25 | 1200 | 800 | 1400 | 350 | 1.0 |
| LDL-40 | 1400 | 900 | 1600 | 550 | 1.3 |
| LDL-60 | 1600 | 1000 | 1800 | 800 | 1.6 |
| LC-80 | 2000 | 1200 | 2000 | 1200 | 2.4 |
5. Applications
| | | |
|---|
| Chemical | Reaction cooling / crystallisation | Stable temperature | Reactor cooling |
| Pharmaceutical | Freeze-drying / cold storage | GMP compliance | Cooling source for freeze dryers |
| Food | Quick-freezing / fresh-keeping | Food grade | Quick-freezing tunnels |
| Laboratory | Low-temperature testing | Precise temperature control | Low-temperature thermostatic baths |
| Electronics | Chip testing | Precise temperature control | Environmental test chambers |
6. Core Component Selection
| | | |
|---|
| Compressor | Compresses the refrigerant | Scroll / reciprocating / screw | Brands: Copeland / Bitzer / Hanbell |
| Condenser | Condenses the refrigerant | Copper-tube aluminium-fin / shell-and-tube | Air-cooled or water-cooled |
| Evaporator | Evaporates and absorbs heat | Stainless steel shell-and-tube / plate | Material selected according to the medium |
| Expansion valve | Throttles and reduces pressure | Thermostatic / electronic expansion valve | Electronic valves give more accurate control |
| Control system | Coordinates operation | PLC + touch screen | PID temperature control + safety protection |
| Filter drier | Removes impurities and moisture | Copper / stainless steel body | Replace the core periodically |
| Liquid receiver | Stores the refrigerant | Steel pressure vessel | Safety valve required |
| Safety system | Protects the equipment | High/low pressure / oil pressure / temperature | Multiple interlocking protection |
7. Design Standards and Certifications
| | | |
|---|
| Relevant GB/T standards | Design and manufacture | Fully compliant | Type test report |
| GMP (cGMP) | Design, manufacture, documentation | Fully compliant | GMP compliance certificate |
| ISO 9001:2015 | Quality management system | Certified | ISO 9001 certificate |
| CE certification | Machinery safety / EMC | Optional | CE declaration of conformity |
| FDA | Food / pharmaceutical grade | Optional | FDA compliance documents |
8. Custom Optional Configurations
| | | | |
|---|
| 1 | Condensing method | Air / water-cooled | Air-cooled | Water-cooled +1 week |
| 2 | Compressor brand | Copeland / Bitzer / Hanbell | Copeland | Imported +2 weeks |
| 3 | Refrigerant | R22/R404A/R23 | R22 | Eco refrigerant +1 week |
| 4 | Temperature control | PID/PLC/DCS | PID | DCS +2 weeks |
| 5 | Evaporator material | Stainless steel / titanium tube / copper tube | Stainless steel | Titanium tube +2 weeks |
| 6 | Explosion-proof | Standard / ExdIIBT4 | Standard | Explosion-proof +2-3 weeks |
9. Material Property Requirements
| | |
|---|
| Operating temperature | -40~250℃ | Depends on seals and materials |
| Corrosivity | Mild to moderate corrosion | Strong corrosion requires 316L or a lining |
| Explosion-proof requirement | Selected according to the site | Zone 1 / Zone 2 differ in grade |
10. Warranty Terms
| | | |
|---|
| Main equipment warranty | 12 months | All components included | 12 months from successful commissioning |
| Extended warranty (optional) | 24 months | Same as standard warranty | Must be purchased with the order |
| Wear-parts warranty | 6 months | Seals, bearings, etc. | Normal wear excluded |
11. Packaging and Delivery
| |
|---|
| Standard lead time | 6-10 weeks after order confirmation |
| Custom configuration lead time | 10-16 weeks |
| Incoterms | FOB Shanghai / CIF / DAP |
| Packaging | Export wooden case |
| Shipping | Container or break-bulk vessel |
12. Information Required for Inquiry
| | |
|---|
| 1 | Required refrigeration temperature | ℃ |
| 2 | Cooling capacity required | kW |
| 3 | Cooled medium | Water / oil / air / other |
| 4 | Condensing preference | Air / water-cooled |
| 5 | Power supply specification | V/Hz |
| 6 | Explosion-proof requirement | Standard / explosion-proof |
| 7 | Compressor brand preference | Domestic / imported |
| 8 | Installation environment | Indoor / outdoor / altitude |
