From our Cryogenic Research Center we turn liquid-nitrogen and CO₂ science into more than a dozen ready-made applications—from IQF and rapid cooling to CFU reduction and deep metal treatment—each proven on ISO-built tunnels, spirals and cabinets that fit your exact throughput and hygiene goals.
The same liquid-nitrogen and CO₂ science drives very different results depending on where you put it. Below is a quick glance at how our core technologies translate into value across four key sectors.
Cryogenics plays a vital role in the food and beverage industry, offering ultra-fast cooling and freezing solutions that enhance product quality and extend shelf life. One of the most recognized uses is cryogenic freezing, where food is rapidly cooled using gases like liquid nitrogen or carbon dioxide. This results in smaller ice crystals, reduced dehydration, and superior texture, taste, and appearance.
Crust freezing is another key application—where only the outer layer of a product is frozen, allowing for clean, precise slicing without compromising the internal structure. Cryogenics is also widely used for glazing, such as cooling oils or sauces to form a smooth coating on products, particularly in coating tumblers or during seasoning of ready meals before final freezing.
In seafood processing, sub-cooling fish to -50°C allows for the immediate formation of a protective water-ice layer when briefly dipped in water. This improves storage life and product integrity.
Additional applications include product stabilization, where partial freezing increases viscosity, making foodstuffs easier to shape or portion. Cryogenics also plays a crucial role in temperature control during processing: in high-speed mixers and blenders, cryogenic injection offsets heat buildup caused by mechanical energy, maintaining safe temperatures and preventing bacterial risk.
In poultry processing, surface cryo-treatment can reduce bacterial counts—such as Campylobacter—by flash-freezing the skin.
Furthermore, in dairy and desserts, cryogenic cooling can be used to emboss logos or flatten surfaces of semi liquids products like yogurt, custard or ice cream, offering branding and visual appeal.
From protein processing to ready meals and seafood, cryogenic technology delivers clean, efficient, and high-performance solutions tailored to modern food production needs.
In the cryobiology sector, cryogenics is essential for the freezing and preservation of biological samples such as cells, tissues, reproductive materials, or vaccines. A clear distinction is made between the freezing process itself and the long-term storage of already frozen materials.
At Dohmeyer, we specialize in the freezing stage—where a living cell is carefully cooled until it enters a dormant state. This process requires precision and the correct freezing curve, as uncontrolled temperature drops can cause irreversible cellular damage. In contrast, cryogenic storage—keeping materials frozen for months or years—is performed in standard commercial storage tanks and is outside our scope.
We design and manufacture controlled-rate freezers, which gradually lower the temperature according to a precise time-temperature profile suited to each biological material. This method is critical for sensitive samples like stem cells, embryos, or blood components, where uniform ice crystal formation is vital.
For samples requiring rapid freezing, we offer blast freezers that deliver maximum thermal force to quickly bring temperatures down—ideal for high-throughput or robust materials.
Additionally, Dohmeyer builds immersion freezers for directional freezing, where straws or vials are submerged into liquid nitrogen to control ice crystal growth across a single axis—used in advanced research and cryo-preservation protocols.
Whether it's for human cells, veterinary samples, or biotech R&D, Dohmeyer’s cryogenic expertise ensures safe, consistent, and reproducible freezing conditions tailored to your application.
Cryogenics plays a critical role in the production of today’s most advanced pharmaceuticals—particularly in mRNA therapies, vector DNA-based treatments, and cell therapies. Unlike traditional pharmaceuticals that rely on solid-dose formulations like pills or capsules, these modern biologics involve injectable liquids that contain fragile, highly sensitive molecules requiring precise thermal management at every step.
During the synthesis of mRNA or vector DNA, cryogenic systems are often used to control reaction temperatures, stabilize reagents, and preserve the biological integrity of active materials. In the formulation stage, cryogenics is essential for the production of lipid nanoparticles (LNPs)—tiny delivery vehicles that encapsulate mRNA for safe and efficient delivery into human cells. These nanostructures must be formed and stored at low, stable temperatures to retain their structure and functionality.
Cryopreservation is also key in cell therapies, where living cells must be frozen using tightly controlled freezing curves to ensure survival and therapeutic efficacy after thawing. Dohmeyer specializes in controlled-rate freezers that enable repeatable, precise freezing processes suited to the demands of cell-based and genetic medicines.
From R&D to clinical manufacturing, cryogenic technology is no longer optional—it is foundational in enabling the next generation of personalized and curative treatments.
Cryogenic technology is becoming a key enabler in modern recycling, especially when it comes to separating complex or tightly bonded materials. By exposing materials to extremely low temperatures, their physical properties—such as flexibility, brittleness, or adhesion—change dramatically, allowing for clean, chemical-free separation.
A common application is in copper wire recycling. When copper wires coated with PVC insulation are cryogenically cooled to around -100 °C, the PVC becomes brittle while the copper remains flexible. This difference allows the two materials to separate easily, without burning, shredding, or releasing harmful toxins.
A common application is in copper wire recycling. When copper wires coated with PVC insulation are cryogenically cooled to around -100 °C, the PVC becomes brittle while the copper remains flexible. This difference allows the two materials to separate easily, without burning, shredding, or releasing harmful toxins.
The same principle applies in tire recycling, where cryogenic cooling makes the rubber brittle enough to break away cleanly from embedded steel reinforcements, improving the efficiency of material recovery.
Cryogenics is also used to pre-treat plastics for grinding. Frozen plastics become more fragile, making them easier to break down into fine particles that can be sorted and recycled more efficiently.
One of the fastest-growing applications is in battery recycling—including electric vehicle batteries and smaller lithium-ion batteries from laptops and electronics. These batteries are hazardous due to their chemical content and flammability. Cryogenic treatment renders the batteries inert by freezing the electrolyte and depressurizing the cells. This makes them safer to dismantle and allows for the clean recovery of metals like lithium, cobalt, and copper, as well as plastics and housing materials.
A highly specialized application is in explosive ordnance disposal (EOD), particularly for unexploded ordnance (UXO) such as landmines, munitions, and cluster bombs. Immersing these items in liquid nitrogen causes their components—metals, explosives, and plastics—to become brittle and inert. This allows safe mechanical dismantling without risk of detonation and enables full material recovery in an environmentally responsible manner.
From industrial waste to defense and energy sectors, cryogenics delivers safe, efficient, and sustainable recycling solutions.
Cryogenics offers powerful solutions across a wide range of industrial processes, especially where precision, material behavior, or extreme thermal control are critical. These applications are typically highly customized, designed to meet specific engineering challenges.
One key use is cryogenic deburring of rubber and plastic parts. By exposing molded components to extremely low temperatures, burrs become brittle and detach cleanly—improving product finish without manual effort.
In metal treatment, cryogenic temperatures are used in deep cryogenic quenching to transform retained austenite into martensite. This strengthens the metal, increases wear resistance, and enhances long-term stability in tools and mechanical parts.
Another common application is cryogenic grinding. Many industrial powders—such as pigments, polymers, or spices—can only be micronized effectively by freezing the material first. This prevents heat build-up and smearing, ensuring uniform particle size.
In emissions control, cryogenic condensation is used to recover or neutralize volatile organic compounds (VOCs) from exhaust gases. These valuable or hazardous vapors condense onto cryogenically cooled surfaces, allowing for safe disposal or recovery.
Cryogenic environmental chambers enable accelerated life-cycle testing. Products are subjected to repeated freezing and heating cycles to simulate aging, stress, and material fatigue—providing valuable insights into performance and durability.
From deburring to VOC recovery, cryogenics supports cleaner, more precise, and more durable industrial processes across multiple sectors.
Freezing is a critical process in food preservation, impacting product safety, shelf life, and quality. Two predominant methods are mechanical freezing, typically operating around -40°C, and cryogenic freezing, which utilizes extremely low temperatures, often around -100°C or lower.
This article provides a scientific and unbiased comparison between these methods, focusing on hygienic design, heat transfer efficiency, equipment footprint, and effects on food quality. Notably, we reference Dohmeyer’s latest top-lifting tunnel and spiral freezers, recognized for their superior heat transfer performance and hygienic construction.
Hygienic design is paramount in food processing to prevent microbial contamination. Mechanical freezers often incorporate internal evaporator coils, fan assemblies, and complex ductwork. These components not only create dead corners but also become potential reservoirs for biofilm formation and bacterial colonization.
Cryogenic freezers, especially those engineered by Dohmeyer, eliminate these components entirely. Their top-lifting tunnel design opens the entire chamber for cleaning access, and sloped, weld-free internal panels prevent fluid retention and allow efficient drainage. With no heat exchangers, fans, or ducts inside the food zone, cryogenic systems reduce cleaning cycle time and the use of aggressive detergents, contributing to both better hygiene and lower operational costs.
The rate of heat removal during freezing is governed by Newton's Law of Cooling, where the temperature gradient (ΔT) between the product and the cooling medium is the key driving force. Cryogenic systems operating at -100°C provide a ΔT of 90–100°C versus ambient food temperatures (~0°C), while mechanical freezers at -40°C offer a much smaller ΔT of ~40°C.
This difference results in much faster heat transfer in cryogenic systems. According to research, heat transfer coefficients in cryogenic systems range between 100–140 W/m²·K, compared to 15–17 W/m²·K in mechanical air-blast systems.
Given the substantial reduction in freezing time (79% on average), cryogenic systems require much shorter residence times. This results in significantly more compact equipment. Furthermore, cryogenic freezers lack bulky internal evaporators, defrost assemblies, and air recirculation systems, allowing cryogenic systems like Dohmeyer’s top-lifting tunnel to achieve equivalent throughput in less than 25% of the floor space compared to mechanical alternatives.
The quality of frozen food is closely related to the size and distribution of ice crystals. Smaller, uniformly distributed crystals maintain the integrity of cellular structures, while larger crystals cause mechanical rupturing of cell walls, leading to various quality losses.
Faster freezing leads to smaller ice crystals, reducing intracellular damage. Cryogenically frozen products show 30–50% lower drip loss compared to mechanical freezing.
Surface dehydration occurs primarily between -1°C and -5°C, where moisture sublimates. Mechanical systems expose products to this zone for 10–30 minutes, causing up to 3–5% moisture loss. Cryogenic freezing reduces exposure to under 3 minutes, limiting dehydration to less than 1%.
Cryogenic freezing rapidly halts enzymatic and oxidative processes, preserving flavor compounds. This ensures a taste closer to fresh products.
Color retention is improved due to reduced enzymatic browning. Fruits and vegetables retain their natural color more effectively.
Smaller ice crystals preserve cellular structure, improving texture and firmness after thawing.
While cryogenic systems consume liquid nitrogen, they avoid complex defrost cycles and long run times. The trade-off often favors cryogenics for high-value products.
While cryogenic systems consume liquid nitrogen, they avoid complex defrost cycles and long run times. The trade-off often favors cryogenics for high-value products.
Dohmeyer’s cryogenic solutions, including its top-lifting tunnel and spiral freezers, represent the industry benchmark for high-performance, hygienic, and compact freezing equipment in food and biotech applications.
Premium ice cream, particularly in pint-sized (450 ml) paperboard containers, requires careful handling during freezing to preserve air incorporation (overrun), texture, and product integrity.
This article provides a scientific comparison between cryogenic freezing (typically using liquid nitrogen at -90°C to -100°C) and mechanical hardening tunnels (-35°C to -45°C) in the context of high-fat, aerated dairy emulsions. Emphasis is placed on heat transfer kinetics, structural outcomes, packaging deformation, and industrial throughput.
Ice cream is a complex multiphase system of ice crystals, air bubbles, fat globules, and unfrozen sugar solution. Key thermal characteristics include:
The rate of ice cream hardening is governed by the overall heat transfer coefficient U, surface area A, and temperature gradient ΔT:
Ice cream 'drawn' from the freezer contains 30–100% overrun. Cryogenic hardening:
Mechanical tunnels risk cup deformation due to long exposure. Cryogenic freezing:
Cryogenic hardening in ~15 min allows inline integration, while mechanical tunnels require 60–90 min residence and large infrastructure. Benefits:
Cryogenic systems consume LN₂, with energy externalized. Mechanical systems rely on electricity for compressors and fans. Cost-efficiency depends on volume and supply chain context.
Cryogenic systems need LN₂ infrastructure and packaging must be suitable for rapid freezing. However, they are ideal for high-quality, flexible production scenarios.
Cryogenic freezing at -90°C offers substantial thermal and quality advantages for premium pint ice cream. With faster freezing, better texture retention, and integration into modern lines, it provides a high-performance alternative to conventional mechanical tunnels.
In the processing of ready-to-eat (RTE) meals, freezing is not just a preservation method—it's a critical determinant of texture, safety, and post-thaw consumer experience.
This article presents a scientific comparison between cryogenic and mechanical freezing systems, focusing on heat transfer mechanics, product integrity, hygienic requirements, and spatial efficiency. Each chapter is grounded in empirical findings and food engineering principles, with minimal commercial language.
The efficacy of freezing depends on Newtonian heat transfer dynamics:
Where ΔT is the temperature gradient between product core (~+5°C) and cooling medium (cryogenic gas or refrigerated air). Cryogenic systems offer ΔT ≈ 100°C; mechanical systems offer ΔT ≈ 35-40°C.
Cryogenic hardening in ~15 min allows inline integration, while mechanical tunnels require 60–90 min residence and large infrastructure. Benefits:
Lasagna slice (300g): Cryo = 9 min, Mech = 38 min
Rice + sauce tray (250g): Cryo = 7 min, Mech = 32 min
Mac & cheese (200g): Cryo = 6 min, Mech = 28 min
Chicken curry + rice (350g): Cryo = 10 min, Mech = 42 min
Couscous + vegetables (250g): Cryo = 8 min, Mech = 30 min
Average freezing time reduction: ~76.5%
This sharper thermal gradient ensures:
The microstructure of complex meals—especially those combining protein, starch, and emulsified fats—is highly sensitive to freezing dynamics.
The microstructure of complex meals—especially those combining protein, starch, and emulsified fats—is highly sensitive to freezing dynamics.
Ready meal lines process cooked, often high-risk foods. Cleaning protocols are stringent.
Smooth internal walls, sloped drainage, and top-lifting access improve cleanability and reduce downtime between shifts.
Surface dehydration occurs mainly in the -1°C to -5°C plateau. Longer time in this zone increases sublimation.
Consequences:
Surface dehydration occurs mainly in the -1°C to -5°C plateau. Longer time in this zone increases sublimation.
A 76.5% reduction in freezing time translates into shorter conveyors or spirals. Without bulky fans or evaporators, cryogenic systems:
Meals with thermal heterogeneity—such as rice + curry or pasta + sauce—freeze unevenly in traditional systems.
Cryogenic gas flow ensures:
Mechanical freezers remain widespread in bulk commodity processing. However, for ready meals that require fine control of texture, moisture, and reconstitution quality, cryogenic systems offer scientifically validated advantages.
Faster freezing, better hygiene, and higher food integrity make them a preferred choice for demanding food engineering environments.
Rubber, plastics or spices are chilled to –196 °C, become brittle and fracture cleanly during milling. You get consistent particle size with lower energy and blade wear.
Rubber, plastics or spices are chilled to –196 °C, become brittle and fracture cleanly during milling. You get consistent particle size with lower energy and blade wear.
Parts cool to –180 °C, transforming retained austenite and boosting wear resistance; a controlled re-heat locks in dimensional stability. Widely used for cutting tools, gears and motorsport.
Parts cool to –180 °C, transforming retained austenite and boosting wear resistance; a controlled re-heat locks in dimensional stability. Widely used for cutting tools, gears and motorsport.
Paddle mixers meter LN₂/LCO₂ straight into the moving mass, holding a tight temperature band while you blend up to 15 % seasoning. Result: colour, flavour and texture stay consistent.
Paddle mixers meter LN₂/LCO₂ straight into the moving mass, holding a tight temperature band while you blend up to 15 % seasoning. Result: colour, flavour and texture stay consistent.
Product cascades deck-to-deck through LN₂ or CO₂ snow, reaching ≤ –110 °C in minutes. Moisture locks inside so berries, diced meat or veggies remain completely separate for packing.
Product cascades deck-to-deck through LN₂ or CO₂ snow, reaching ≤ –110 °C in minutes. Moisture locks inside so berries, diced meat or veggies remain completely separate for packing.
A brief surface shock-freeze inflicts lethal thermal stress on microorganisms, cutting colony counts in seconds. Shelf-life and safety rise while taste and colour stay intact.
A brief surface shock-freeze inflicts lethal thermal stress on microorganisms, cutting colony counts in seconds. Shelf-life and safety rise while taste and colour stay intact.
An extreme temperature gradient freezes from the outside-in, minimising ice-crystal growth and drip loss. Texture, flavour and nutrients remain virtually unchanged.
An extreme temperature gradient freezes from the outside-in, minimising ice-crystal growth and drip loss. Texture, flavour and nutrients remain virtually unchanged.
From 0.1 to 3 000 K/min, the system follows bespoke temperature profiles and logs every second for full traceability. Ideal for biologics, electronics or material research.
From 0.1 to 3 000 K/min, the system follows bespoke temperature profiles and logs every second for full traceability. Ideal for biologics, electronics or material research.
LN₂ forces rapid micro-crystallisation of fat layers in cones or bars, giving a smoother texture and longer shelf-life. Production speeds up while bloom risk drops.
LN₂ forces rapid micro-crystallisation of fat layers in cones or bars, giving a smoother texture and longer shelf-life. Production speeds up while bloom risk drops.
Ultra-cold conditions let you dose up to 23 % water in one pass to create a clear, even glaze. The layer shields seafood or vegetables from dehydration during storage.
Ultra-cold conditions let you dose up to 23 % water in one pass to create a clear, even glaze. The layer shields seafood or vegetables from dehydration during storage.
A thin outer shell forms at cryogenic temperatures, locking shape for slicing, battering or decorating while the core stays pliable. Dimensional accuracy and yield improve dramatically.
A thin outer shell forms at cryogenic temperatures, locking shape for slicing, battering or decorating while the core stays pliable. Dimensional accuracy and yield improve dramatically.
Sublimating CO₂ cools pastes, batters or doughs fast, tightening texture without adding moisture. Smoother, more predictable flow boosts throughput and portion accuracy.
Sublimating CO₂ cools pastes, batters or doughs fast, tightening texture without adding moisture. Smoother, more predictable flow boosts throughput and portion accuracy.
Gentle cryogenic pull-down lets you press precise logos, patterns or complex 3-D shapes into food without sticking. The design holds steady through subsequent processing.
Gentle cryogenic pull-down lets you press precise logos, patterns or complex 3-D shapes into food without sticking. The design holds steady through subsequent processing.
A controlled blast of liquid nitrogen or CO₂ removes heat in seconds, dropping core temperature with minimal dehydration. Perfect as an intermediate step before slicing, packing or glazing.
A controlled blast of liquid nitrogen or CO₂ removes heat in seconds, dropping core temperature with minimal dehydration. Perfect as an intermediate step before slicing, packing or glazing.
A rotating, nitrogen-cooled drum tumbles product through chocolate, sauces or dry seasoning for a perfectly uniform layer. Simultaneous cooling stabilises texture and extends shelf-life.
A rotating, nitrogen-cooled drum tumbles product through chocolate, sauces or dry seasoning for a perfectly uniform layer. Simultaneous cooling stabilises texture and extends shelf-life.
Materials are chilled to their brittle point and fractured without dust or energy-intensive grinding. The cold break-up simplifies downstream recycling and cuts overall power use.
Materials are chilled to their brittle point and fractured without dust or energy-intensive grinding. The cold break-up simplifies downstream recycling and cuts overall power use.
Everyone knows the disappointment of biting into an ice cream cone, only to find the sugar cone soggy. In popular impulse ice creams like the Cornetto, this happens because moisture from the ice cream gradually softens the sugar cone. To prevent this, manufacturers spray a thin layer of chocolate-flavoured fat glaze inside the cone before adding the ice cream. This glaze acts as a moisture barrier.
However, there’s a catch. The glaze is applied in liquid form at about 40°C, and it takes time to crystalise. If the ice cream is added too soon, it scrapes away the still-soft glaze, making the protection ineffective. As a result, the cone absorbs moisture, and its crunch disappears long before the ice cream’s shelf life ends.
Dohmeyer has solved this with a breakthrough in cryogenic technology. Dohmeyer equipment freezes the glaze instantly—within just 0.3 seconds after spraying. This ultra-fast crystallisation locks the fat layer in place before the ice cream is added, ensuring it stays intact.
The result? A perfectly crisp cone, even after months in the freezer. Shelf life has been shown to improve from an average of 6 months to 18 months. It’s a small technical fix with a big impact on taste and quality—because nobody likes a soggy cone.
Nitrogen stamping is a clever application of extreme cold, developed by Dohmeyer, to solve a common problem in food processing—sticking. Whether it’s flattening a the fruitlayer under the yoghurt or flattening a box of ice cream, conventional metal stamptools often get messy. That’s where nitrogen stamping comes in.
The stamp is a special stainless metal plate, soaked in liquid nitrogen until it reaches –196°C. At this temperature, the surface of the stamp becomes much colder than the product’s vitrification point—the point where water or organic material turns glassy and rigid rather than forming ice crystals. When food touches the stamp, it doesn’t smear or stick. Instead, the surface is chilled so rapidly that it becomes non-adhesive for a brief moment.
This effect is partly explained by the Leidenfrost phenomenon: when something very cold (or hot) touches a much warmer surface, a thin vapor layer forms between them. This barrier reduces contact and prevents sticking. In nitrogen stamping, the stamp can hit the food, flatten it, and retract—all in one clean motion. There’s no residue, no mess, and no interruption in production.
The process works especially well with soft, sticky foods like custards, fruit purées, and dairy desserts. Since the food never actually freezes solid or bonds to the stamp, the equipment stays clean, and the results are consistent.
In short, nitrogen stamping turns an age-old problem into a neat, scalable solution—thanks to physics and a bit of liquid nitrogen magic.
Cryo-coating is an advanced food technology developed and refined by Dohmeyer, enabling the precise and uniform application of sauces or seasonings to frozen food ingredients.
It combines deep cryogenic freezing with a controlled layering process to deliver coated products with high visual and sensory appeal, while maintaining structural integrity and consistency.
The process begins by cryogenically freezing the core product—vegetables, meat, pasta, or rice—to approximately –55°C. At this temperature, the food is not just frozen; it is loaded with cold energy, meaning the surface has strong thermal inertia. This ultra-low temperature is key, because when a liquid seasoning or sauce is sprayed onto the surface, it immediately freezes upon contact, forming a thin, even layer that adheres tightly without dripping.
What makes cryo-coating unique is its layering method. After the first spray of seasoning is frozen onto the product, the batch is cryogenically chilled again to return the surface to –55°C. A second layer is then applied and immediately frozen, followed by a third. This way we can adhere 9x the original starting weight. Each cycle builds a thicker shell of frozen sauce around the core. This stepwise approach allows incredible precision: producers can choose to apply as little as 10% coating (10 kg of sauce per 100 kg of product), or up to 700% (700 kg of sauce per 100 kg of product).
This method is particularly effective for producing individually quick frozen (IQF) ready-meal components, such as rice meals, mixed vegetable dishes, vol-au-vent chicken or beef Stroganoff style. The only thing limit is your imagination: penne arabiata, pasta genovese with pesto, or corn soup.
In the production of formed food products such as hamburger patties, chicken nuggets, or plant-based alternatives, achieving a consistent mixture is critical. These blends—typically made from minced meat or alternative proteins, combined with seasonings and binders—must reach a precise viscosity to ensure smooth processing through forming machines.
But natural ingredients vary: fat content, water retention, and structure can change from batch to batch, impacting product consistency and leading to shape irregularities or production inefficiencies.
To address this, Dohmeyer has developed a cryogenic injection system that retrofits directly onto existing industrial blenders (GEA, Seidelmann, FPEC, N&N,...) The system consists of bottom-mounted injection nozzles capable of delivering either liquid nitrogen (LN₂) or liquid carbon dioxide (LCO₂) during the blending process. This allows processors to stabilize the temperature and control the viscosity of the mix in real time—regardless of ingredient variation.
The innovation lies in the versatility of the nozzle: a single design that withstands both the ultra-low temperatures of liquid nitrogen (–196°C) and the high working pressures of liquid CO₂ (400psi /28bar). This means processors can freely switch between cryogens based on availability, cost, or gas supplier—without hardware changes.
During operation, the cryogen is injected precisely as the mixture is blended. Sensors monitor temperature and adjust dosing to maintain optimal conditions, typically just below the freezing point. At this stage, the paste becomes firm but pliable—ideal for forming with maximum yield.
The result: a repeatable, standardized process that ensures every batch flows, forms, and performs exactly the same—day after day.
IQF, or Individually Quick Frozen, is a method of freezing food items one by one, rather than in bulk. The principle is simple: each shrimp, each broccoli floret, each piece of pasta or diced meat should come out of the freezer as an individual, free-flowing unit. While it may sound straightforward, in practice, achieving true IQF quality is technically demanding.
The reason lies in the physics of water. Most food items contain between 60% and 90% water. When water freezes, it expands—by approximately 9%—as it turns to ice. That expansion can cause pieces of food, even if laid separately on a belt, to touch and fuse during freezing. Once frozen together, these bonds are rock-solid and nearly impossible to break without damaging the product.
It’s not just about the manpower involved : even carefully placed, manually sorted products can stick together during freezing. That’s why Dohmeyer has developed a range of equipment that actively prevents sticking during the freezing process, rather than trying to solve it after the fact.
The first innovation is the Three-Deck Freezer (also known as the 3-Tier Freezer). This tunnel freezer uses three conveyor belts stacked vertically. Products enter on the top belt and are partially frozen before dropping onto the second belt. The drop naturally breaks any weak bonds that might have started forming. The second belt runs about 15% faster, helping spread and separate the pieces further. The same process repeats from the second to the third belt. By the time the product exits fully frozen, the separation is guaranteed. This design is ideal for small meat cuts, fish portions, or pizza toppings—not for large, flat products like patties or filet.
For higher volumes and space efficiency, Dohmeyer also offers the Multi-Belt Freezer, featuring 5, 7, or even 9 belts stacked within a walk-in housing. This system operates on the same principle as the Three-Deck Freezer but offers greater capacity in a more compact footprint. The product falls from one belt to the next in a controlled way, continuously separating and freezing belt after belt. It’s especially suitable for processors with limited floor space and high-throughput requirements.
When processing sticky or delicate products that tend to crumble—like vegan meat analogs or ground beef —the Cryoroll offers a completely different approach. This cylindrical, rotating tunnel gently tumbles product as it moves along a slight incline. Internally, fins lift and drop the product continuously, ensuring movement and separation. Liquid nitrogen or CO₂ is injected directly into the drum, freezing the product while it’s in motion. Because the CryRoll is a sealed system, no product or fines are lost, making it ideal for high-value materials or fine particulates like rice, ground meat, or plant-based mixes.
A close cousin of the Cryroll, the Cryogenic Tumbler operates on the same principle but in batch mode. The drum is filled, closed, and then tumbled while cryogen is introduced. It’s a highly controlled environment, guaranteeing zero product loss. While it shares the advantages of the Cryroll in terms of handling fragile or particulate-heavy ingredients, its main difference is its batch nature
All these systems share one objective: delivering perfectly frozen, non-sticking, individual pieces—no matter the input format. Whether your product comes in clumps, shreds, or loose flow, Dohmeyer’s cryogenic technology ensures separation throughout the freezing process, not just at the end. And unlike mechanical post-freezing separation, which risks damaging the product, Dohmeyer systems preserve the structure, appearance, and integrity of every piece.
From vegetables and fish to alternative proteins and meat, IQF is the gold standard for product quality and consumer convenience.With their deep expertise and range of tailored solutions, Dohmeyer stands as one of the most advanced developers of IQF technology worldwide.
Dohmeyer opracował kilka systemów dostosowanych do przemysłowego Cryo-Fracturing (kruszenie), oferując wydajne i skalowalne rozwiązania dla szerokiego zakresu wyzwań związanych z recyklingiem.
Każda z tych technologii opiera się na precyzyjnej kontroli przepływu chłodziwa, równomiernym schładzaniu oraz bezproblemowej integracji z istniejącymi procesami mechanicznymi.
Used tires are composed of rubber reinforced with steel wire. They’re shredded into thumb-sized chunks and cooled to around –90°C in a machine called the CryoRoll. At this temperature, the rubber becomes glass-hard, while the embedded steel remains flexible. After cooling, the frozen tire pieces are fed into a hammer mill, which breaks apart the brittle rubber, liberating the steel. The result: a clean separation into fine rubber powder and coiled metal wire, ready for reuse.
Residual paint in discarded metal cans makes recycling difficult. By cryogenically cooling these cans to around –100°C, the paint solidifies and becomes fragile. The can is then crushed or fractured mechanically. The paint breaks off in flakes, while the metal structure remains intact. This clean separation allows both components—metal and paint—to be recovered and recycled independently.
Copper wires, often coated in PVC or Teflon insulation, are difficult to process through traditional means. Using cryo-fracturing, wires are immersed in liquid nitrogen or exposed to cryogenic air, cooling them to as low as –196°C (for Teflon). After freezing, the wire is flexed or passed through rollers. The plastic insulation cracks and disintegrates, while the copper inside stays flexible and intact. This process enables near-complete recovery of clean copper and reduces manual labor.
Some applications don’t involve composite separation but benefit from cryo-fracturing to produce ultrafine powders. Vulcanized rubber granules (buffings) from recycled tires are cooled to –100°C and then passed through high-speed mills. Because the rubber is pre-cooled, it absorbs the mechanical heat generated during milling without softening, enabling micron-level size reduction. The result is a free-flowing, reactivatable rubber powder used in new tires or industrial components.
Certain plastics become brittle at low temperatures and can be cryo-shredded into clean, consistent flakes. For complex polymer waste streams or contaminated plastics, cryogenic embrittlement allows for rapid size reduction without the smearing or clogging typical in warm shredders. The flakes can be sorted and remelted more easily, improving downstream recycling yields.
One of the most promising—and necessary—applications of cryo-fracturing is battery recycling. Batteries, whether from laptops, electric vehicles, or household electronics, contain metals, plastics, and black mass (a valuable mix of lithium, cobalt, and other fine particles). But they also pose a major risk: when exposed to air or physical damage, lithium-ion cells can undergo thermal runaway—essentially catching fire or exploding.
This auto-combustion is triggered by internal reactions between the electrolyte, air, and temperature rise due to mechanical stress. Cryo-fracturing provides a safe and controlled way to deactivate the battery before disassembly. Research and industrial experience have shown that cooling batteries below –80°C effectively eliminates all residual charge and electrochemical activity. At these temperatures, even damaged cells become inert.
Once inert, the frozen batteries can be crushed or opened safely. Plastics and metals can be separated through mechanical means, while the black mass can be collected with minimal risk of ignition.
Dohmeyer has developed systems specifically for this application, where batteries are submerged in cryogenic chambers and automatically discharged before entering crushing and sorting lines. This ensures safety and recovery in one streamlined process.
Cryogenic treatment, often referred to as deep cryogenic treatment (DCT), is a metallurgical process that involves cooling metals to extremely low temperatures, typically around –180°C, to enhance their mechanical properties.
This process has garnered significant attention in industries such as aerospace, automotive, and tooling, where material performance is critical.
One of the primary objectives of cryogenic treatment is the transformation of retained austenite into martensite. Retained austenite is a softer phase that can compromise the hardness and dimensional stability of steel. By subjecting steel to cryogenic temperatures, the retained austenite transforms into martensite, a harder and more stable phase, thereby improving the material’s overall performance.
Additionally, cryogenic treatment promotes the precipitation of fine carbides within the steel matrix. These carbides enhance wear resistance and contribute to the material’s hardness. The uniform distribution of these carbides ensures consistent performance across the treated component.
Empirical studies have demonstrated that cryogenic treatment can lead to significant improvements in mechanical properties. For instance, research on AISI 420 stainless steel revealed that cryogenic treatment increased hardness and impact toughness. The treated samples exhibited a more refined microstructure with uniformly distributed carbides, leading to enhanced wear resistance .
In another study focusing on X17CrNi16-2 martensitic stainless steel, deep cryogenic treatment resulted in increased hardness, tensile strength, and wear resistance. The transformation of retained austenite to martensite and the precipitation of fine carbides were identified as the primary mechanisms behind these improvements.
The aerospace industry has been at the forefront of adopting cryogenic treatment due to its stringent material performance requirements. Components such as landing gear, turbine blades, and structural elements benefit from the enhanced fatigue life and dimensional stability provided by cryogenic treatment. Companies like Boeing and Airbus have incorporated cryogenic treatment into their manufacturing processes to meet these demands.
Similarly, the automotive industry utilizes cryogenic treatment for components like gears, crankshafts, and brake rotors. The improved wear resistance and reduced residual stresses contribute to longer service life and reduced maintenance costs.
A typical cryogenic treatment cycle involves a controlled cooling phase, where the component is gradually cooled to the target temperature (around –180°C) to prevent thermal shock. The component is then held at this temperature for a specified duration, often ranging from 12 to 36 hours, to ensure complete transformation of retained austenite and carbide precipitation. Following the cryogenic hold, the component is slowly returned to room temperature and may undergo tempering to relieve any induced stresses and stabilize the microstructure.
It’s essential to note that the effectiveness of cryogenic treatment depends on the material’s composition and prior heat treatment. Not all steels respond equally to cryogenic treatment, and the process parameters must be tailored to the specific material and desired properties.
Cryogenic treatment is a scientifically validated process that enhances the mechanical properties of metals through microstructural transformations. By converting retained austenite to martensite and promoting fine carbide precipitation, the process improves hardness, wear resistance, and dimensional stability. Its adoption in critical industries underscores its value in producing high-performance components.
As research continues to refine the understanding of cryogenic treatment mechanisms, its applications are expected to expand further across various sectors.
Cryo-grinding is a precision grinding process in which materials are cooled to sub-zero temperatures before or during mechanical milling. While conventional grinding processes are widely used in food and industrial sectors, they often face limitations due to frictional heat.
This localized heat buildup can lead to volatile loss, smearing, oxidation, or even combustion of certain products. Cryo-grinding, using cryogenic nitrogen (–196°C) or offers an effective and proven solution.
One of the most common applications of cryo-grinding is in the food industry—especially for spices, herbs, and other aromatic compounds. Black pepper, nutmeg, cinnamon, turmeric, and even coffee beans are rich in volatile essential oils responsible for their distinct aroma and flavor. However, during standard milling operations, the mechanical impact of grinding raises the local surface temperature sharply, often exceeding 60–90°C. This thermal spike causes essential oils to vaporize, leading to significant loss in flavor and aroma.
Studies have shown that spice grinding at ambient temperatures can result in aroma loss of up to 40% due to volatilization of compounds such as eugenol, piperine, and limonene. Cryo-grinding, by pre-cooling the kernels (e.g. black peppercorns) to temperatures around –100°C, prevents this loss. The stored cold energy buffers against the heat produced during grinding, maintaining the product below its volatilization point. As a result, the essential oils remain intact and are delivered to the final consumer, preserving freshness, flavor intensity, and shelf life.
Another key domain of cryo-grinding is in the processing of heat-sensitive or thermoplastic materials. Vulcanized rubber, thermoset plastics, sulfur, waxes, and even pharmaceuticals can pose challenges in traditional mills. Under high shear and impact, these materials tend to soften, melt, or smear, causing build-up inside the mill and loss of particle uniformity. In worse cases, fine powders like sulfur can ignite, presenting a serious explosion hazard.
By cooling such materials to below their glass transition temperature—typically between –60°C and –110°C—they become brittle and fracture cleanly under impact. For example, micronizing rubber at –90°C allows production of ultra-fine powders without sticking. Sulfur, which poses combustion risks when milled in air, remains stable and non-reactive when pre-frozen and milled in a cryogenic, oxygen-free atmosphere.
In addition to temperature control, cryo-grinding introduces a significant safety benefit: an inert atmosphere. The vaporized nitrogen or carbon dioxide displaces oxygen inside the grinder, significantly reducing the risk of dust explosions—particularly important for combustible powders like flour, sulfur, or certain polymers. This inert environment also minimizes oxidation, which is critical for products like turmeric or green tea that are highly sensitive to oxygen exposure.
The combination of physical cooling and oxygen displacement gives cryo-grinding a unique double advantage: preserving product quality while also preventing ignition and degradation.
Cryo-grinding is not merely a technological upgrade—it is a necessity in industries where product quality, safety, and performance cannot be compromised. Whether the goal is to preserve delicate aromas in spices or to process industrial materials safely and cleanly, cryogenic milling has been shown to significantly outperform ambient grinding.
Dohmeyer’s cryogenic screw feeder systems have been integrated globally into spice mills, chemical plants, and recycling lines. Their ability to precisely chill, dose, and inert grinding processes has made them essential equipment for producers seeking consistency, safety, and high-quality output.
In a time when customers demand fresher food, cleaner processes, and safer operations, cryo-grinding offers a cold, but decisive, advantage.
IQF, or Individually Quick Frozen, is a method of freezing food items one by one, rather than in bulk. The principle is simple: each shrimp, each broccoli floret, each piece of pasta or diced meat should come out of the freezer as an individual, free-flowing unit. While it may sound straightforward, in practice, achieving true IQF quality is technically demanding.
The reason lies in the physics of water. Most food items contain between 60% and 90% water. When water freezes, it expands—by approximately 9%—as it turns to ice. That expansion can cause pieces of food, even if laid separately on a belt, to touch and fuse during freezing. Once frozen together, these bonds are rock-solid and nearly impossible to break without damaging the product.
The reason lies in the physics of water. Most food items contain between 60% and 90% water. When water freezes, it expands—by approximately 9%—as it turns to ice. That expansion can cause pieces of food, even if laid separately on a belt, to touch and fuse during freezing. Once frozen together, these bonds are rock-solid and nearly impossible to break without damaging the product.
The reason lies in the physics of water. Most food items contain between 60% and 90% water. When water freezes, it expands—by approximately 9%—as it turns to ice. That expansion can cause pieces of food, even if laid separately on a belt, to touch and fuse during freezing. Once frozen together, these bonds are rock-solid and nearly impossible to break without damaging the product.
The reason lies in the physics of water. Most food items contain between 60% and 90% water. When water freezes, it expands—by approximately 9%—as it turns to ice. That expansion can cause pieces of food, even if laid separately on a belt, to touch and fuse during freezing. Once frozen together, these bonds are rock-solid and nearly impossible to break without damaging the product.
The reason lies in the physics of water. Most food items contain between 60% and 90% water. When water freezes, it expands—by approximately 9%—as it turns to ice. That expansion can cause pieces of food, even if laid separately on a belt, to touch and fuse during freezing. Once frozen together, these bonds are rock-solid and nearly impossible to break without damaging the product.
The reason lies in the physics of water. Most food items contain between 60% and 90% water. When water freezes, it expands—by approximately 9%—as it turns to ice. That expansion can cause pieces of food, even if laid separately on a belt, to touch and fuse during freezing. Once frozen together, these bonds are rock-solid and nearly impossible to break without damaging the product.
The reason lies in the physics of water. Most food items contain between 60% and 90% water. When water freezes, it expands—by approximately 9%—as it turns to ice. That expansion can cause pieces of food, even if laid separately on a belt, to touch and fuse during freezing. Once frozen together, these bonds are rock-solid and nearly impossible to break without damaging the product.
The reason lies in the physics of water. Most food items contain between 60% and 90% water. When water freezes, it expands—by approximately 9%—as it turns to ice. That expansion can cause pieces of food, even if laid separately on a belt, to touch and fuse during freezing. Once frozen together, these bonds are rock-solid and nearly impossible to break without damaging the product.
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