Visiting a factory in Shenzhen, China

Hi, I'm a Filipino Citizen going to Hong Kong from October 19- 24 for a trade. But we planned to visit a factory in Shenzen for a day and head back to Hong Kong. We currently don't have a chinese visa, what are my options so I can visit a factory to see machine and just come back? I heard we can apply in Hong Kong, is my case possible?

Additional Information
I'm leaving next monday, I don't want to take the risk of sending my Passport for an entry permit in the Philippines since it might takes days to be returned and I might not be able to fly to Hong Kong