喷涂料施工的回弹控制｜Controlling Rebound in Refractory Gunning

摘要：喷涂料报价便宜、落地成本未必低，差额在回弹率里。讲回弹的四个来源：风压、距离、角度与水比，以及操作手法与验收怎么抓。
Abstract: Gunning mix quotes cheap but lands expensive — the gap is rebound. Four drivers: air pressure, distance, angle and water ratio, plus technique and how to verify.

正文： 喷涂料施工完一算账，材料的实际挂壁量比理论用量少了一截，差额躺在地上扫走的回弹料里。回弹率 15% 到 40% 都是常态，这一项就是喷涂料和浇注料报价比价时最容易漏掉的账。
Main text: After gunning, the material that actually sticks falls short of theory — the difference is rebound swept off the floor. Rates of 15 to 40 percent are normal, and it is the line item most often missed when comparing gunning mix against castable.

一、回弹的四个来源
1. The four sources of rebound

风压过大，颗粒砸在墙上弹回来；喷嘴距离过远，动能不足粘不住；喷射角度偏斜，斜着打出去的料大半弹走；水比失当，早了挂不牢、晚了料淌下来。四项里风压和距离由机手掌握，占比最大。
Too much air pressure bounces particles off; too far a nozzle starves impact energy; oblique spray throws most of the mix away; wrong water ratio leaves it unbonded or slumping. Pressure and distance sit with the nozzle operator and dominate.

二、操作手法的三条纪律
2. Three rules of nozzle technique

• 喷嘴与受喷面保持 0.8 到 1.2 米，基本垂直，偏差不超过 15 度。
  Hold the nozzle 0.8 to 1.2 m from the surface, near-perpendicular, within 15 degrees.
• 喷枪匀速画圈推进，不要对着一点猛灌。
  Sweep in steady circles; never blast one spot.
• 分层喷涂，单层 50 毫米上下，前一层初凝后再上后一层。
  Spray in passes near 50 mm; let each set before the next.

三、怎么验收回弹
3. How to verify rebound

开工前和机手约定计量方式：按送料量与挂壁量之差算回弹率，回弹料称重记录。把验收写进施工合同，比口头强调十次都有用。回弹料降下来的收益，够买好几年的检测服务。
Agree the measurement up front: rebound is feed volume minus what sticks, with the swept material weighed and logged. Put it in the contract — more effective than ten verbal reminders. The savings from lower rebound will buy years of inspection services.