Author: Peter Below 

Is there any way to disable the mouse wheel for a particular application or form?

Answer:

You can use a handler for the Application.OnMessage event to filter out messages 
(e.g WM_MOUSEWHEEL) before any control in your application sees them. Note that 
this will not work with all mouse drivers. There are some that can be configured to 
not post the standard wheel messages but to send WM_VSCROLL messages instead if the 
control under the mouse has scrollbars. This "compatibility mode" is there to make 
the wheel usable with applications that do not have wheel support build in.

1   procedure TMainForm.FormCreate(Sender: TObject);
2   begin
3     Application.OnMessage := AppMessage;
4   end;
5   
6   procedure TMainform.Appmessage(var Msg: TMsg; var Handled: Boolean);
7   begin
8     Handled := msg.message = WM_MOUSEWHEEL;
9   end;
10  
11  if you only want to do this for a specific form class you would modify this method 
12  to
13  
14  procedure TMainform.Appmessage(var Msg: TMsg; var Handled: Boolean);
15  begin
16    Handled := (msg.message = WM_MOUSEWHEEL) and
17      (Screen.Activeform is TMySpecialFormclass);
18  end;