{"id":2856,"date":"2026-09-24T02:00:00","date_gmt":"2026-09-24T02:00:00","guid":{"rendered":"https:\/\/yiyizk.com\/?p=2856"},"modified":"2026-09-24T02:00:00","modified_gmt":"2026-09-24T02:00:00","slug":"batch-reactor-sizing","status":"publish","type":"post","link":"https:\/\/yiyizk.com\/id\/blog\/batch-reactor-sizing\/","title":{"rendered":"Ukuran Reaktor Batch: Volume, Waktu Siklus, dan Kapasitas Produksi"},"content":{"rendered":"

Batch reactor sizing starts with production demand and a verified batch cycle\u2014not with a catalog vessel volume.<\/strong> Calculate the required batches per period, determine the liquid working volume for one batch, add the process-specific allowances for agitation, foaming, gas space, thermal expansion, and charging, then check whether the proposed reactor can heat, cool, mix, transfer, clean, and turn around each batch within the assumed cycle. The final nameplate volume is normally larger than the working liquid volume. Because reaction kinetics, heat release, physical properties, pressure, and relief requirements are process-specific, qualified process and mechanical engineers must validate the design.<\/p>\n

Start from the production basis<\/h2>\n

State the required saleable mass or volume per day, operating days, shifts, campaign length, expected yield, normal rejects, and planned downtime. Distinguish annual average from peak demand. A reactor sized only on yearly production may be unable to meet a short campaign; one sized on an unrealistic peak may be permanently underfilled.<\/p>\n

Convert demand to reactor output using consistent units and a defined product density. If the recipe is mass-based, keep the balance in mass until density is needed for volume. Document the reference temperature because liquid density and volume can change with temperature. For a multi-product plant, repeat the calculation for the controlling recipe rather than assuming the largest finished batch is always the hardest case.<\/p>\n

\"Engineer<\/p>\n

Calculate batches and working volume<\/h2>\n

A useful first relationship is:<\/p>\n

Batches required per period = required good product \u00f7 good product per batch.<\/strong><\/p>\n

Good product per batch equals charged material adjusted by conversion, separation losses, transfer heel, sampling, and other demonstrated losses. Do not hide all losses inside one unexplained \u201cefficiency\u201d factor. A transparent mass balance makes later scale-up and troubleshooting possible.<\/p>\n

For a liquid batch, the preliminary working volume is the maximum liquid volume expected at any point in the recipe\u2014not necessarily the starting charge or final product volume. Semibatch addition, solvent generation, gas holdup, phase expansion, and quench can make an intermediate step controlling. Evaluate every recipe stage.<\/p>\n\n\n\n\n\n\n\n\n\n
Sizing input<\/th>\nQuestion to answer<\/th>\nEvidence<\/th>\nCommon error<\/th>\n<\/tr>\n<\/thead>\n
Production target<\/td>\nHow much good product is required in the peak period?<\/td>\nApproved forecast and operating calendar<\/td>\nUsing annual average only<\/td>\n<\/tr>\n
Working volume<\/td>\nWhat is the maximum liquid volume during the recipe?<\/td>\nRecipe and material balance<\/td>\nUsing final batch volume<\/td>\n<\/tr>\n
Fill limit<\/td>\nWhat headspace is required for mixing, foam, gas, and expansion?<\/td>\nProcess trials and hazard review<\/td>\nApplying a generic percentage<\/td>\n<\/tr>\n
Cycle time<\/td>\nHow long from ready-to-charge to ready-to-charge?<\/td>\nStep-level schedule<\/td>\nCounting reaction time only<\/td>\n<\/tr>\n
Availability<\/td>\nWhat planned and unplanned downtime is credible?<\/td>\nMaintenance and production history<\/td>\nAssuming continuous availability<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Convert working volume to vessel volume<\/h2>\n

Once the maximum working volume is known, establish the maximum permitted fill fraction. This is a process decision, not a universal rule. Low-viscosity, nonfoaming service may tolerate a different fill level from gas-evolving polymerization, vigorous powder wet-out, or vacuum deaeration. The agitator must remain adequately submerged at minimum level while the high level must preserve disengagement space and prevent carryover into vents or relief devices.<\/p>\n

The preliminary vessel volume can be expressed as required working volume \u00f7 permitted fill fraction<\/strong>. Treat the result as a screening value. Then choose a practical geometry and verify actual dimensions, head volumes, nozzle intrusions, jacket coverage, agitator location, and usable drain volume. Nameplate capacity alone does not describe usable process volume.<\/p>\n

Build the complete batch cycle<\/h2>\n

Cycle time begins when the clean, released reactor is ready to charge and ends when it is again ready to charge. Include raw-material staging, charging, heating, reaction hold, controlled additions, sampling and laboratory release, cooling, transfer, heel recovery, rinsing, cleaning, inspection, documentation, and expected waiting. Identify which steps can overlap outside the vessel and which occupy it.<\/p>\n

Capacity is constrained by the longest credible cycle, not the fastest demonstration run. Calculate batches per day from available operating time divided by cycle time, then round down to a whole number. Add a schedule margin supported by operating data. If three nominal eight-hour batches fit exactly into 24 hours, any sampling delay or cleaning problem causes a missed batch.<\/p>\n

\"Operator<\/p>\n

Check heat transfer before accepting the size<\/h2>\n

A larger batch stores more reaction heat while jacket area does not increase in the same proportion as volume. Estimate sensible heating and cooling loads, heat of reaction, addition heat, phase-change duty, agitation input, and credible utility temperatures. Then evaluate heat-transfer area, overall coefficient, fouling, viscosity, jacket zones, and control response. For exothermic service, normal duty and emergency response are separate checks.<\/p>\n

The University of Colorado Boulder\u2019s LearnChemE stirred-tank energy balance summary<\/a> explains that mass and energy balances are normally solved together. OSHA\u2019s process safety management guidance<\/a> provides context for process safety information and hazard analysis in covered chemical processes. These educational resources do not replace a project-specific design basis.<\/p>\n

Verify mixing, transfer, and cleaning<\/h2>\n

Scaling volume without checking mixing can change blend time, heat transfer, suspension, gas dispersion, and local concentration. Provide viscosity versus temperature, density, solids size and settling behavior, interfacial behavior, gas rate, shear sensitivity, and required blend uniformity to the agitator designer. Motor power alone is not a complete scale-up rule.<\/p>\n

Confirm that feed lines can charge within the cycle, pumps can transfer the batch at minimum and maximum viscosity, the outlet drains the intended heel, and downstream equipment can receive the batch. Cleaning time and validation may control utilization in multi-product service. Review our multi-product batch reactor selection guide<\/a> and jacketed reactor heating and cooling guide<\/a> for related decisions.<\/p>\n

Worked screening example<\/h2>\n

Assume a campaign requires 8,000 kg of good product per day. A proposed batch yields 2,000 kg of good product after documented losses, so four batches are required. If the complete cycle is 5.5 hours, four batches occupy 22 hours and leave two hours of schedule margin. If the maximum recipe volume is 2.6 m\u00b3 and the process-approved maximum fill fraction is 70%, the preliminary vessel volume is 2.6 \u00f7 0.70 = 3.71 m\u00b3. The next practical size must still pass heat-transfer, agitation, pressure, relief, support, transfer, and cleaning checks.<\/p>\n

This example is intentionally a method demonstration. It is not a recommended fill fraction or equipment size. Real values must come from the specific chemistry, physical properties, operating envelope, hazard review, and supplier drawings.<\/p>\n

Information to include in an RFQ<\/h2>\n