Lamiline - Rosemex

1 Lamiline FACE AND BY-PASS COILDAMPER UNITSR osemex Products VENTILATION4961 CONTENTSLAMILINE FACE AND BY-PASS COIL/DAMPERUNITS provide an effective and convenient method ofpreheating fresh air supply to a controlled leaving tem-perature with a minimum risk of freezing the coil. Thearrangement of alternate narrow coil and by-pass sec-tions provides effective mixing of the streams of heat-ed and unheated air, and the temperature of the mixedair is controlled by modulating the face and by-passdampers. By keeping the steam (or water temperature and flow) full-on until the entering air temperature is wellabove freezing (40-50 ), the possibility of freezing thecoil is almost eliminated. Overheating during the peri-od when the entering air is near the required tempera-ture for leaving air, and the face dampers are fullyclosed (but where it is not considered safe to modulatethe steam or water), is minimized by special damperseals.

2 Additionally, a down-stream damper inter-linked withthe face and by-pass dampers so that it remains fullyopen for most of the control range, and closes rapidlyat the end of the control range as the face damperbecomes fully closed, is normally provided. Thisdamper is of double construction with hollow cross-section and acts as a heat baffle to reduce radiationfrom the face of the coil. By this combination of special damper seals and heatbaffle the temperature over-ride can be kept to a max-imum of from 5-8 which is usually easily compensat-ed for in the re-heating further down-stream. ALL Lamiline DAMPERS are special extruded alu-minum shapes designed for rigidity, and because thePages 3-7 General informationPage8 Circuiting and head lossPages 9-11 Selection of type W unitsPages 12-13 Selection of type S unitsPages 14-15 Installation and pipingPages 16-17 Dimension and weights horizontal tube units typical specificationsPages 18-19 Dimension and weights verticaltube units typical specificationsextrusions are always uniform a good fit is positioning of the dampers and damper sealmullions is assured in manufacture by the use of amultiple punch and die set which simultaneouslypunches all of the damper shaft and mullion screwholes for each section of the Lamiline unit.

3 Lamiline units are offered with vertical tubes forsteam applications and with horizontal tubes for waterand steam applications. The vertical tube units arerecommended where steam is being used for preheat-ing applications because there is less possibility offreezing. The single-pass construction, with thesteam header at the top and the condensate header atthe bottom provides for rapid clearing of headers are generously sized to assure goodsteam distribution, and the condensate header is thesame size as the steam header to take care of surgesof condensate which may occur on start up and as anadded safety precaution against back-up of conden-sate. WHERE HORIZONTAL TUBE STEAM Lamiline units seem to be indicated for a preheating applicationdue to the configuration of the inlet opening, goodresults can be obtained by using extra care in selec-tion and installation.

4 If available space permits, single-pass coils (opposite end headers) should be used, andthe unit should be sloped approximately 1/4 inch perfoot toward the condensate end. There is no built-inslope in the Lamiline units. If a two-pass (same end header) coil must be used itshould be limited to 60 inches in length, and care mustbe taken to see that the unit is installed with the tubesabsolutely level, as any slope in either direction maycause water-hammer and would also increase thedanger of freezing. WHERE HOT WATER UNITS ARE USED FOR PRE-HEATING, the water must be kept at full flow ratethrough the coil and preferably at full temperature untilthe entering air is well above freezing. Ethylene Glycolsolutions may be used, and information is included inthe water coil selection data as to the adjustments tobe made in calculations. Lamiline face and by-pass units are also suitable forapplications not involving freezing air.

5 The availableselection of sizes (9 increments in width and 1 incre-ments in length) lends itself to fitting LAMILINES tostandard air handling VFACE AND BY-PASS COIL/DAMPER UNITS2 CONSTRUCTIONLAMILINE face and by-pass coil damper unit casingsare one-piece welded construction of heavy gauge gal-vanized steel. Corners are gusseted to prevent twistingof the casing. A special welding process is used whichminimizes damage to the galvanized coating of thesteel and a galvacon coating is applied over the weldas a further protection. COIL SEGMENTS are of copper tube mechanicallyexpanded into aluminum plate fins. (Copper fins areavailable at added cost.) Coils are one-or two-row con-struction, but it is recommended that for preheatingapplications two-row always be used. Two-row seg-ments have staggered tubes to minimize the by-passfactor of the coil.

6 Fin spacing is either 6 FPI or 12 FPIas required. HEADERS are electric welded steel pipe, and thetubes are brazed into the headers. In vertical tube unitsthe coil segments are attached to the upper tube sheetand float freely in the lower tube sheet to allow forexpansion. The tube sheets have flanged holesthrough which the tubes pass and in which they canmove without damage to the tubes. EXPANSION BENDS are provided at the lower end ofthe tubes of vertical tube units, and at the condensateheader end of horizontal tube units having oppositeend headers, to allow for expansion and units having same end headers have specialreturn bends which allow for expansion and contrac-tion. Hot water units with opposite end headers havethe expansion bends at the return header in order toprovide the off-setting of the header required to facili-tate coil segment removal.

7 EXPANSION OF THE HEADERS is allowed for in themethod of attaching the individual tube sheets to themain casing, which allows for adequate side move-ment. REMOVAL OF INDIVIDUAL COIL SEGMENTS is pos-sible without disturbing the headers or piping. This isillustrated in the pictures on the opposite is from the down-stream side after having firstremoved the down-stream damper. No extra space need be provided above or below thecoil (or on either end in the case of horizontal tubeunits) for pulling of damper shafts. The construction ofthe blades, which can be seen in the illustration onpage 6, is such that continuous shafts are notrequired and the blade can be removed by simplyunbolting the blades from the damper shaft at eachend. In the case of long blades which are divided intotwo or more sections the intermediate bearing sup-ports are removable.

8 Removal of the coil segment itself is done by cuttingthe tubes between the coil and header. The new seg-ment is then inserted and the tubes connected bymeans of standard copper sleeves which are silverbrazed in place. This provides an easily made and per-manent leak-free joint. REMOVAL OF FACE AND BY-PASS DAMPERS isalso possible without requiring any additional spacearound the unit by the same means as describedabove for the downstream damper removal. The con-struction of the damper blades and mullions aredescribed and illustrated on page 6. DAMPER LINKAGE is installed on the supply end ofvertical tube units, and on the supply end of horizontaltube units, unless specifically requested otherwise. Ineach case a damper drive shaft with an adjustable armfor attaching the drive rod runs the full height or lengthof the unit. In this way the connecting rod from thedamper motor may be attached at either end of the unitor at any intermediate point.

9 A detail of this arrange-ment can be seen on page 7. DAMPER DRIVE MOTORS should be selectedaccording to the control manufacturer s recommenda-tions for an equivalent area of opposed blade standarddamper. Due to their light weight and operating ingraphite bushings Lamiline dampers are relativelylight operating. However, it is not recommended thatany special allowances be made when selectingdamper drive motors. DOUBLE COIL SECTION UNITS are available forduties requiring a higher temperature rise than is pos-sible with a single coil section. These are supplied in atwo piece casing as illustrated on pages 17 and of an inner coil segment requires removal ofthe outer coil segment, or alternatively if circumstancesallow the casing may be separated to allow access tothe inner coil section. STANDARD STEAM COILS are suitable for steampressures to 15 PSIG and temperatures to 275 F.

10 HEAVY DUTY STEAM COILS may be used for steampressures to 150 PSIG and temperatures to 350 F. STANDARD WATER COILS are suitable for watertemperatures to 250 F and pressures to 160 PSIG. HEAVY DUTY WATER COILS may be used for watertemperatures to 350 F and pressures to 200 PSIG. TESTING of all water and steam coils is done underwater in an illuminated test tank with air at 200 TUBE Lamiline UNITSTYPE LLS-VHORIZONTAL TUBE Lamiline UNITSTYPE LLW-H AND LLS-HEntering air sideLeaving air sideEntering air sideLeaving air side4 COIL AND DAMPER ARRANGEMENTSMOOTH AIRFLOW through Lamiline mixingdampers is maintained by their diverting rather than baf-fling action, so that at no time is a flat surface or pocketpresented to the air stream. A single cross-link betweenthe face dampers and by-pass dampers of each unit isprovided. Another cross-link ties in the down-stream dampers. Thedesign of this link is such that there is very little move-ment of the down-stream blade during most of the trav-el of the face and by-pass blades.