Why sqlliteconnection assigned to static variables are disposed?

I am assigning sqlliteconnection object to static variable and initializing it in a function.

while accessing sqlliteconnection object at some cases it throws "sqlconnection object is disposed" exception. Up to my knowledge static variables are disposed only while application closes.

Sample Code:

public static SQLLiteConnection sql;

public void OpenConnection()
{
     sql = new SQLLiteConnection ;
     //assign sql lite file path
     sql.Open();
}

public void GetStud()
{
  OpenConnection();
 //writing sqlcommand connection
}
}