Modern Krantz exhaust air technology offers cleaning rates of up to 99.9% and at the same time uses the energy potential of the VOCs to generate process heat, cooling and electrical energy. Complex production conditions require specific concepts. We develop exhaust air purification systems that are perfectly tailored to the specialised manufacturing processes of our customers. For this purpose, we determine the exhaust air quality precisely in relation to the production cycles and customise our high-quality cleaning technology as required. This results in maximum cleaning values and cost-saving energy recovery through systematic integration into process energy systems: combined internal and external heat recovery for the generation of production heat and cold, warm water, hot water, thermal oil and steam.

Regenerative thermal oxidation (RTO)

By using ceramic heat regenerators and alternating flow directions of hot clean gas and cold exhaust air, up to 96% of the heat can be kept internally in the system. This means that regenerative oxidation can be operated autothermally from a VOC concentration of approx. 2 g/Nm³. Additional fuel is not required.

• Regetar and Tarmin: 1,000 to 60,000 Nm³/h in 2- or 3-chamber design, from 60,000 Nm³/h in 4- or 5-chamber design; continuously developed since 1990; patented additional buffer system for 2-chamber RTO
• SmartRTO: compact plug and play systems, completely pre-assembled and commissioned, transported by lorry to site, for purchase or rental; 5,000, 10,000, 15,000 and 20,000 m³/h; concentrations < 1,000 mg/Nm³, with buffer up to approx. 3,000 mg/Nm³
• SmartRTO E: purely electrically heated regenerative oxidation for CO₂-neutral operation without fossil fuels; 3,750 and 15,000 Nm³/h in 3-chamber design
• Return-air enrichment fuels: natural gas, propane and butane, hydrogen, high-calorific exhaust air; hydrogen-operated burners under development
• Applications: solvent processing industry; biogas treatment

Catalytic oxidation (CaOx)

Oxidation of the volatile organic compounds in the exhaust air already takes place at reduced temperatures of 280 °C to 380 °C thanks to a catalytic converter. Highly efficient plate heat exchangers recover up to 80% of thermal energy for internal preheating. CO₂-neutral operation using only electrical energy is possible. Catalysts as bulk or honeycomb modules; customised design; compact pre-installed systems; piggyback on production dryers or roof-mounted. Applications: chemical and pharmaceutical; gravure and flexographic print shops; painting and coating.

Thermal recuperative oxidation (TNV): Integra and Flexa

Thermal recuperative oxidation systems TNV are extremely compact systems for cleaning exhaust air from production plants with high heat requirements and problematic exhaust air substances, for condensation-critical, dust-laden and non-residue-free combustible exhaust air. Patented tube bundle heat exchanger: 70% internal heat recovery for Integra (up to 7,500 Nm³/h, integrated exhaust fan), up to 76% for Flexa (up to 60,000 Nm³/h, patented compensator for thermal elongation), with downstream multi-stage external heat recovery to air, warm or hot water, thermal oil, steam and adsorption refrigeration. Applications: printing, coating, laminating, impregnation.

Concentration

We offer sustainable exhaust air purification for large air volume flows with low concentrations of VOC. The pollutants are adsorbed on hydrophobic, non-combustible zeolites and desorbed with a small warm volume flow; concentration ratio up to 1:50; from approx. 10,000 Nm³/h, < 1,000 mg/Nm³, exhaust temperature up to 80 °C. Combined with catalytic, regenerative or recuperative oxidisers, or with micro gas turbines where heat and electricity are continuously required. Concentration with electrically heated catalytic oxidation eliminates fossil fuel.

Industries

Automotive painting processes; pharmaceutical and chemical validated processes; print shops and coil coating; surface coating, impregnation and lamination (styrene, formaldehyde); paint and varnish production; tank storages, where we develop solutions for operating Vapour Recovery Units in combination with regenerative thermal oxidisers, completely without nitrogen oxides and additional CO₂ emissions from fossil auxiliary fuels.

Services

Measurements and process analyses with certified equipment; process selection with in-house combustion simulation software and CFD studies; construction, commissioning and after sales with 3D site scans and proprietary control programs; lifetime maintenance and spare parts; System Check to modernise rather than replace existing plants; the Krantz Clean Air App for IIoT cloud-based storage, display, comparison and optimisation of plant data during operation; used exhaust air purification plants.