Chapter 3 Impingement Filters

Question 1

What are the 4 types of impingement filters?

Answer 1

Panel
Washable metal panel and baffle grease
Roll
Lint

Question 2

Describe a panel filter

Answer 2

Panel filters are media air filters in which the face velocity is the same as the media velocity

Question 3

What types of materials can be use for panel filter construction?

Answer 3

Metal
Spun-glass
Synthetic fibers
Foam

Question 4

When would you use metal as a filter media?

Answer 4

Metals can be used as filter media when they are intended to be washed

Question 5

What types of metals are used in filter media?

Answer 5

Steel and aluminum are used most frequently but stainless or monofilament polypropylene filters are used where corrosion is a concern

Question 6

What are the two categories of metal filters?

Answer 6

Graduated density

Formed screen type

Question 7

Define graduated density media

Answer 7

The upstream side is more open and the downstream side is more densely packed. The purpose is to allow full dust loading by capturing the large particles on the upstream and smaller particles as the air moves through the filter

Question 8

Describe formed screen type filters

Answer 8

A formed screen type filters are made by crimping strips of media to a highly porous filter media. This creates a high capacity and low pressure drop

Question 9

Describe a ring panel

Answer 9

A ring panel is designed with a wire ring sewn thermally sealed or chemically bonded inside a panel made from two or more layers of media

Question 10

Describe an automatic roll filter

Answer 10

An automatic roll filter are devices in which clean media is unrolled at one end, exposed to dirty air stream and advanced at intervals to keep pressure drop through the exposed air stream within a desired operating range

Question 11

What are lint filters used for?

Answer 11

Lint filters are used to capture lint and other fibrous materials such as ink mist in newspaper printing room

Question 12

Describe grease filters

Answer 12

Grease filters are installed in commercial kitchen range hoods to prevent the accumulation of grease in the exhaust ducts. They are all made of metal usually steel of aluminum and provide a torturous path through the filter on which the grease sticks. They are installed at an angle to allow the grease to drain down

Question 13

What is a tackifer?

Answer 13

A tackifer is an adhesive coating on the media to retain dust