DWDI Housing Parts Explorer¶

Run the DWDI Housing Parts Explorer MicroSim Fullscreen

About This MicroSim¶

This MicroSim is an exploded view of a double width, double inlet (DWDI) centrifugal fan housing. The housing sits in the middle. The wiper bar, inlet funnel and bearing structural support are pulled away from each inlet along the shaft line, and the setback outlet flange is lifted off the outlet. Eight parts are labeled: housing side, housing scroll, cutoff, wiper bar, inlet funnel, bearing structural support, setback outlet flange and framing. The wiper bar, inlet funnel and bearing structural support appear twice, once at each inlet, and either copy counts as that part.

The drawing is a simplified illustration based on FanPedia p. 61 (Housing Construction, Centrifugal Fans (DWDI)). The wiper bar and inlet funnel wording comes from pp. 59 and 188, and the bearing location in the airstream comes from p. 167 (Arrangement 3 DWDI). It is not to scale and is not a specific Twin City Fan model.

The check phase shows eight function descriptions in a fixed order. You click the part that matches each one and get two attempts per description. Mastery is 7 of 8 correct on the first attempt. The explore phase is never scored.

#	Description	Part
1	Carries a bearing in front of an inlet, in the airstream.	Bearing structural support
2	Where the discharge duct is bolted to the fan.	Setback outlet flange
3	Separates air leaving the fan from air that would recirculate.	Cutoff
4	Directs air into the impeller from each side.	Inlet funnel
5	Collects air leaving the impeller and guides it toward the outlet.	Housing scroll
6	Reduces turbulence in the inlet funnel area.	Wiper bar
7	Flat sheet that carries an inlet.	Housing side
8	Stiffens the housing and carries it to its mounting.	Framing

How to Use¶

Explore (the starting phase). All eight labels are visible. Click any part to open its infobox. The parts list under the drawing ticks off each part you have opened, and the toolbar counts them.
Check. Press Check after you have opened all eight, or sooner to skip ahead. The labels are hidden and a description appears above the drawing. Click the part it describes:
- Correct: "✓ Correct:" and the part name.
- Wrong: the feedback for that description, for example "The cutoff is the scroll tongue at the outlet; the wiper bar sits at the inlet funnel." You get one more attempt.
- Wrong twice: the correct part is highlighted and marked "Answer", and the description counts as missed.
Press Next description after each answer. The toolbar shows "Parts identified: n of 8", and "✓ Mastered" appears once 7 descriptions are correct on the first attempt.
After the eighth description, the summary shows your first-attempt score and lists any missed parts with their infobox text. Press Restart check to run the check again with the labels hidden, or Back to explore to review.

Keyboard: Tab moves between the parts and the buttons; Enter or Space selects a part. After an answer, focus moves to Next description, so Enter goes on.

Narrow screens: when the drawing is narrower than about 640 px, the callouts become numbers that match the numbered parts list.

Data label: "Simplified exploded view, not to scale · Based on FanPedia p. 61 (DWDI housing construction)", shown below the drawing.

Iframe Embed Code¶

You can add this MicroSim to any web page by adding this to your HTML:

<iframe src="https://moroshek.github.io/FanTASTIC-textbook/sims/ch09-dwdi-housing-parts-explorer/main.html"
        height="858px"
        width="100%"
        scrolling="no"></iframe>

Lesson Plan¶

Learning Objective¶

The learner will identify the eight labeled parts of a double width double inlet housing from a description of each part's job, with at least 7 of 8 correct (Bloom: Remember, verb: identify).

Audience¶

Adult professional development: new application engineers, sales staff, representatives and facilities staff.

Duration¶

10-15 minutes

Prerequisites¶

Chapter 9, section "Double Width Double Inlet Fans": double width double inlet, bearing structural support, setback outlet flange.
Chapter 7: housing side, housing scroll, cutoff, wiper bar, inlet funnel, framing.

Activities¶

Explore (4 min): Open all eight parts. Name the three parts that appear twice and explain why a DWDI housing needs two of each.
Check (5 min): Answer the eight descriptions without going back to the explore phase.
Review (3 min): Read the missed list, reopen those parts, then press Restart check.
Apply (2 min): The bearing structural supports sit in the airstream. What does that mean for a standard Arrangement 3 DWDI fan handling 160°F air?

Common Misconceptions Addressed¶

The bearing structural support is part of the motor base: it is drawn at each inlet carrying a bearing, and the feedback for that description says it is not a motor base.
The cutoff and the wiper bar are the same part: the cutoff is at the outlet and the wiper bars are at the inlet funnels, and the feedback for both descriptions says where each one works.
A DWDI fan has one inlet funnel, like an SWSI fan: the exploded view shows a funnel at each inlet, and either one is accepted.

Assessment¶

Running count "Parts identified: n of 8"; mastery is 7 of 8 on the first attempt, shown as "✓ Mastered".
Opening infoboxes in the explore phase is exploration, not evidence.
Follow-up question: standard Arrangement 3 DWDI fans are limited to clean air at 130°F. Which part in this drawing is the reason?

References¶

FanPedia: The Fan & Blower Encyclopedia (PDF) - Twin City Fan & Blower; p. 61 is the DWDI housing construction drawing this view is based on, pp. 59 and 188 describe the wiper bar and inlet funnel, and p. 167 places the bearings in the airstream on Arrangement 3 DWDI fans.
FanPedia online - Twin City Fan & Blower's online version of the encyclopedia.
Chapter 9: Impeller Construction and Material Handling - the section "Double Width Double Inlet Fans", which defines the bearing structural support and setback outlet flange.
Chapter 7: Housing Construction and Exploded Views - the SWSI housing parts this DWDI housing repeats.