By Vvon Engineering Team | Published | Updated
Specify Semian process abatement from gas chemistry, flow, treatment stages, services and outlet requirements; distinguish tool exhaust from general fume-hood ventilation.
Scientific & laboratory RFQ checklist (TXT)
Semian process-abatement equipment is selected for specified exhaust gases, flows and operating conditions. A semiconductor tool’s exhaust is not the same duty as general room ventilation or a laboratory fume-hood duct. Vvon can review the relevant Semian configurations for laboratory and industrial process enquiries.
Use this guide for the Semian equipment discussion after the process-gas and exhaust brief has been defined. Confirm the exact proposed system and its application limits with the manufacturer. Related reading: Choosing a gas scrubber: matching the machine to the molecule.
List every process, purge and cleaning gas, its normal and maximum flow, concentration, temperature and operating sequence. Include particles, condensable by-products and possible incompatible mixtures. That brief determines which treatment stages need evaluation; a model should not be selected from exhaust volume alone.
Two failure modes come out of skipping this step. The first is a laboratory that buys one scrubber for a shared extract carrying both acid and alkali streams, and finds the reagent neutralising itself. The second is a department that adds a new process two years later, sends an unlisted gas up an existing stack, and discovers at the next emission test that the abatement it paid for does nothing for the compound the inspector measured.
Wet absorption transfers a suitable pollutant into liquid and may react it with a reagent. Other Semian configurations use combustion or thermal stages followed by further treatment. Captured contaminants and reaction products can make the liquid or solid waste hazardous. Neutral pH alone does not authorise drain disposal or prove removal of all pollutants.
A note that saves confusion on site. Semian's MIDAS scrubbers and Honeywell's Midas gas detectors share a name and nothing else. If your project carries both, put the manufacturer in front of the model on every drawing and every purchase order, or the wrong item will reach the wrong contractor at least once.
| Catalogue entry | Correct selection approach | Avoid this assumption |
|---|---|---|
| MIDAS-I | Review its process-abatement stages and approved gas duty | It is not established here as a 500 m³/h general fume-hood wet scrubber |
| MIDAS-II | Confirm the burn/cooling process configuration and approved gases | Do not describe it automatically as a two-stage packed wet tower |
| SBW 200-C / SBW 200-CE | Review the offered burn/thermal-plus-wet arrangement and gas-flow rating | Do not convert process-gas ratings into a claimed number of laboratory hoods |
| Other Semian families | Request a model-specific technical proposal | A family name does not prove media, efficiency, capacity or chemical compatibility |
The Semian product overview from Crystec and its burn-treatment description distinguish process-abatement arrangements. They are manufacturer-representative references; the current Semian technical proposal must establish the delivered model, stages, approved gases and services.
Size on the extract flow the ventilation design actually delivers, not on the number of hoods. A hood at full sash draws considerably more than the same hood at working sash height, and a shared duct serving six hoods is sized against a diversity assumption someone made on a drawing. Get the commissioned flow figure from the ventilation contractor, in m³/h, at the point where the scrubber will sit, before selecting anything.
Agree the operating range, normal and maximum flows, upset response and outlet limits. Excessive oversizing can also affect temperature, residence time or treatment conditions. Removal efficiency must name the gas, inlet condition, method and operating envelope.
Request a services and installation schedule for the offered model. Depending on the design it may need fuel, electricity, air or nitrogen, water, drainage, cooling, extraction and process interlocks. Confirm pressure limits and heat rejection instead of applying one generic pump, pH-probe or 100–300 Pa specification to all Semian units.
The fan is the item most often got wrong. A scrubber added to an existing extract system inserts a pressure drop the original fan was never selected for, and the result is a hood that no longer meets its face velocity. If the scrubber is a retrofit, the fan is part of the scope, and the face velocity at every hood on that system should be measured before and after.
Agree a commissioning and maintenance plan that demonstrates the specified process duty using safe, suitable measurements. Include any environmental tests required for the site. ISO/IEC 17025, BAETE and ABET do not automatically mandate one scrubber model or one universal annual service package.
Keep the current process-gas specification, acceptance results, operating limits, maintenance records and change-control decisions with the responsible site teams. Adding a new gas or process recipe requires compatibility review before connection.
Share your application, equipment requirements and procurement timeline. Our engineers can help clarify the configuration and scope for your enquiry.