Document QMkp77a0VzXLdyEaBxoOx7yw4

I- A FILE N o . JO D ) (A U G U S T . 1936) ' ARCO AIR FILTERS 8 ARCO AIR FILTERS CONSTRUCTION The ARCO Air Filter is a replacement type of filter constructed of corrugated fibre board, so arranged as to form cellular passages. Each filter is composed of two wafers. In the No. 1 Filter the cellular passages in both wafers are the same size. In the No. 2 and No. 25 the cellular passages in the wafer on the inlet side are larger than the passages in the wafer on the outlet side. The cellular passages in the wafers are "V" shaped on a 90 angle. The two wafers are separated by a } strip, and are bound in a heavy fibre frame to make a complete unit. OPERATION The dust laden air entering the filter immedi ately changes direction on a 45 angle, thus causing a scrubbing along the sides of the cellu lar passages in the first wafer. After leaving the cellular passages in the first wafer, the air abruptly changes direction on a 90 angle, scrubbing along the sides of the passages in the second wafer. As dust impinges on the sides of the cellular passages, oil is absorbed by capillary attraction into each dust particle, and that dust particle then becomes the medium for catching other dust particles. These, in turn, absorb oil and become the new medium for dust arrestance. and this process continues until the filter be comes completely dust laden. COATING The coating is a special compound which is odorless, remains tacky at minus 10 F. and will not drip at 180 F. It does not contain anv substance that will become rancid. The special compound is sprayed on all wafers, before they are assembled into one unit, at a temperature that insures thorough penetration of the fibre board. 13515 fc. i V BASIS FOR SELECTION OF \ A REPLACEMENT TYPE AIR FILTER HE function of an air filter is loclean the air. Tso it might seem that the most efficient air filter would be the one to select. But there are other elements than efficiency that enter into the selection of an air filter. Types of Filters The most efficient filters may be most efficient only when clean, and the efficiency mav drop, as tlie filter becomes dust laden, to a point where dirt actuallv passes through. See Chart No. 1 on page 4. On the other hand, a filter mav ha\e a hitth efficiencv when clean but mav de posit the dirt onlv on its surface and in a vcrv short time build up such a resistance that the air flow is materially obstructed. See Chart No. 2. Or efficiencv mav be obtained at a verv great expense in power consumption, due to the hid) resistance set up bv the filter. See Chart No. 3. Mill another type of filter may be built at a cost out of all proportion to the benefits ob tained. and owe its high efficiencv to its heavv. cumbersome construction. Factors to Consider I he filter that embodies the followin': five factors is the one to select. 1. Low maintenance cost. 2. Effective efficiencv throughout the life of the filter, until full\ dust-laden. 3. Low resistance to the air in relation to effective efficiencies. 1. Large dust-carrving capacitv. 5. Lniform efficiencies and resistances of any one filter and among all filters of the same tvpe. In addition, these factors must be considered in the selection of a replacement type filter: that the filter shall be odorless and remain odorless: that its viscous coating shall not harden under low temperature or run off at high temperature. All of these are fundamental requirements of any effective filter and are embodied in the design of the ARCO Air Filter. Uniform Efficiency of ARCO Air Filters From the charts on pages 6 and 7, the effi ciencies of ARCO Air Filters arc demonstrated. It will be noted that the efficiencies do not decrease, but rather increase as the filters be come dust-laden. This action is due to the fact that ARCO Air Filters carrv a considerable quantitv of viscous, tacky oil that is contin uously absorbed through capillary attraction bv the dust as it impinges on the walls of the filter passages. The oil-laden dust, adhering to the tacky surface, becomes the media for arrest ing other particles of dust as thev come into the filter. The ability of the fibre board material, of which ARCO Air Filters are made, to absorb and hold considerable viscous oil and to give up this oil to dry dust as needed accounts for the uniformly high efficiencv of ARCO Air Filters throughout their life, until the filter becomes fully dust-laden. The charts also show that the resistance in ARCO Air Filters is low when the filters are clean and builds up very slowly and uniformlv as the filter becomes dust-laden. This low re sistance results in low power consumption and insures the full volume of air passing through the filter under all operating conditions. This method of arresting the dust in the filter, by absorbing viscous oil. accounts for the 13516 exceptionally large dust-carrying capacity of ARCO Air Filters. The dust firmly adheres to the sides of the angular passages and builds up evenlv until eventually the filter is completely filled. The space between the two wafers, or two halves of the filter, provides additional dust-carrying capacity. Uniform In Construction Uniformitv in efficiencv and uniformity in re sistance are outstanding features of ARCO Air Filters. The AREA. DEPTH and ANGLE of everv cellular passage in each wafer or side of an ARCO Air Filter are exactlv alike -- and exactlv alike in all ARCO Air Filters of the same tvpe. Therefore, engineering calculations of volume of air. velocity of air. size and speed of the fan. and power consumption may he ap plied to all ARCO Air Filters of the same type. There are no variations, so commonlv found in many other types of filters. ARCO Air Filters are dependable in their performance alike to the manufacturer, the installer, and the user of apparatus involving air cleaning. Pollen Removal Hay fever, with its yearly toll of several million dollars in economic loss, as well as the enormous amount of suffering it causes, has been traced partlv to the pollen and dust which fill the air. When the air breathed by the hay fever patient is cleansed of pollens, great relief is experienced. The pollen removal characteristics of the ARCO Air Filter render its use extremely effec tive in the treatment of hay fever. Tests indi cate efficiencies of 999c when these filters are used in tandem, and well over 955c lor single filters. Charts on actual tests, illustrating common faults in some competitive filters Numerals at bottom are based on equal time intervals. ; Chon No. 1 Illustrative of a filter which falls off in efficiency as it becomes loaded. In this case filter will pass dust after a very short period of operation. Chart No. S Illustrative of a filter having a rela* lively high efficiency but extremely low dust capacity. In a short time scarcely any air will pass through. Chort No. 3 The rapidly increasing resistance of the filter illustrated here indicates that a high power consumption would be required in operation. t 13517 ACTUAL DIMENSIONS OF STANDARD SIZES STANDARD SIZES 16" x 20' x 2" 16" x 25' x 2" 20' x 20' x 2' Nominal Sizes ...16" x 20' X 2" . .16' x 25' x 2" .20" x 20" x 2" Actual Dimensions A Bc IVs" lVs" 15 V%' 15Vs' 19%' 19 H* 24 Vs' 19%' Note: A replacement. Size ... .16" x 20" x 2" . 16" X 25" x 2" . 20" x 20" x 2" 20" \ 25" x 2" A lJs' U-s" 1 'V' Us' B 15 15ys'" 19%" 19%' C i9 Vi' 24 U" 19%" 24 v16 Size . ..16" x 20" x 2" . . 16" \ 25" x 2" .20" X 20" x 2' . .20" x 25" x 2" A U's" U's" 1' Us" B 1574" 15yg" 19%' 19%' c 19 H" 2 4 Vs" 19%' 24 lii nominal sizes allow sufficient clearance for ease REGULAR STOCK SIZES 15' x 20' x 2" 10' x 20" x 2' 10' x 10" x 2" Ty pe No. 2 No. 2 No. 2 Nominal Sizes ................................... 15" x 20" x 2" ................................. 10" x 20" x 2" ...............................................................10" x 10" x 2" T ype No. 25 No. 25 No. 25 . Size ................................................. 15' x 20" x 2" ............................................... 10' x 20" x 2" ..................................................... 10" x 10" x 2' Actual Dimensions AB 1H" 14%' Uis' 9H' nr 9%" c 19% 19 Us1 9 %' A IVs" IVs" B 14%" 9 Vs" 9%' c 19'V 19Vs' 9%' Special sizes aud thicknesses other than the aboxe can be furnished on application. 13518 TYPES OF ARCO AIR FILTERS >0. 1 -- Inlet wafer lit" corrugated: outlet wafer Jfe' corrugated. For high efficiency industrial applications such as air compressors and internal combustion engines. "Vo. 2 -- Inlet wafer Ke" corrugated: outlet wafer corrugated. For ventilating systems, or for furnace and air conditioning installations where a portion of air handled is outside air. Usually installed in tandem in ventilating systems. No. 25 -- Inlet wafer corrugated: outlet wafer corrugated. For installations where major part of air handled is recirculated air. SIZES AND THICKNESS OF ARCO AIR FILTERS ARCO Air Filters are furnished in standard and regular stock sizes, shown on page 5. However, thev can be made in any size and in any thickness to meet your requirements. Several concerns are using a single-pass ARCO Air Filter 1' thick, made of corrugated fibre board, which shows an initial resistance of .02 W.C., with a relatively high cleaning efficiency. This is an illustration of our ability to furnish filters to meet all needs. PERFORMANCE DATA FOR ARCO AIR FILTERS The following data is based on tests made using dust of a concentration of one ounce to 50.000 cu. ft. of air. The dust used is a mixture of 50% lamp black and 50% coal ash by weight, passed through a 100 mesh screen. The dust is thoroughly dried before being tested. PERFORMANCE OF NO. I FILTERS INDUSTRIAL! TYPE RESISTANCE OF CLEAN FILTERS AT VARIOUS AIR VELOCITIES RESISTANCE and efficiency of filter WHILE LOADING AT VARIOUS CFU It should be borne in mind that dust concentration of one ounce to 50.000 cu. ft. of air, which is the quantity used in these tests, is abnormallv high and, hence, the continuous time intervals indicated by numerals at bottom of charts may each represent several days or even weeks, depending upon the actual amount of dust in the air where the filters are installed. 13519 RESISTANCE OF CLEAN- FR.TERS Ar VARIOUS AIR VELOCITIES mi m mE <HBBBBBBBBBBHMBBBl[ij BBBBSIBBBBBBBBBBBBBBB BBBBBBBBBflflBBBBBBEflB BBBBBBflflflBBBBBBflBBflR: BBBBBBBBBBBBBBflflBpaB ____ !BBBR& Li-< hbl .9- O- II 12- U- - - IT * PERFORMANCE OF NO 25- FILTERS FURNACE OR LOW RESISTANCE! TYPE . RESISTANCE OF CLEAN FUERS. . AT VARIOUS- AIR VELOCITIES RESISTANCE AND EFFICIENCY^ OF FILTERWHILE. 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