The phrase "a number of intense" is correct and usable in written English.
It can be used to describe multiple instances or occurrences of something that is strong or extreme in nature.
Example: "The team faced a number of intense challenges during the project, but they managed to overcome them."
Alternatives: "several intense" or "many intense".
The active region, AR 9393, produced a number of intense flares during March April 2001.
"There have been a number of intense but fairly short-lived storms this year, unlike last year where we figure we would have only named about seven.
It was just one of a number of intense, gory sequences that earned Jaws the reputation of being the most shocking movie ever to be awarded a family-friendly PG rating in the US.
He formed a number of intense, apparently sexual bonds with other men, and he lost his security clearance and his position at the RAND Corporation after he was arrested for soliciting sex in a men's room in Santa Monica, Calif.
A self-portrait and a portrait of an elderly woman, both clothed and on seven-foot tall canvases from 1983, plus a number of intense, graphite pencil-on-paper portraits display skills that few young artists today are bothering to acquire.
A number of intense post-earthquake landslides and debris flows in the Wenchuan earthquake-hit region were reported.
I've been to any number of intense shows, but never have I felt so completely at the mercy of the crowd as I did that night.
In his maturity, Rore produced a number of remarkably intense madrigals for the court of Parma.
In the current series of "44 Scotland Street" we have had a number of fairly intense developments in the plot.
(He has lived for some years now in Hawaii, where his interest in the preservation of rain forests has prompted a number of lovely, intense poems with a strong ecological edge).
A number of sharp intense lines were found in 350 650-nm spectral regions.
