How much sperm is produced in a second/minute/hour?
Sperm production is medically call spermatogenesis and occurs surrounded by seminiferous tubules in the testis. Sperm has its own enthusiasm period, i.e., even if it is unused, it will die on its own and is absorbed by the body. Spermatogenesis, spermiogenesis and the storage of sperm contained by the epididymis occur over relatively long period of time. The sperm produced by ejaculation today started its course of development roughly speaking 3 months ago. So, it's impossible to quantify the amount of sperms produced in one hour!
Once ejaculate, it may take in the region of an hour or more to replenish but your next ejaculation will be smaller amount. Probably about 1/2 a teaspoon.
The number of sperm cells produced vary with the size of the testicles, but averages 85 million sperm per light of day per testicle, and decreases near age. This means that a single mannish may produce more than a quadrillion (1,000,000,000,000) sperm cells surrounded by his lifetime!
Between 200 and 600 million sperm cells are typically released in respectively ejaculation.