5
FIGURE 4.
SINGLE BURNER SCANNER SIGHTING
FIGURE 5.
SCANNER LOCATION VS. SECONDARY AIR ROTATION
2.
An acceptable scanner location must ensure the following:
— Reliable igniter flame detection.
— Reliable main flame detection.
— Rejection of igniter flame too short or in the wrong position to ignite the main flame reli-
ably.
Note: Reliable signals must be obtained at all air flows, furnace loads (ranges of fuel firing) and
desirable fuel air ratios.
3.
If combustion air enters the furnace with a rotational movement of sufficient velocity to deflect
igniter flame in the direction of rotation, position the scanner 0 to 30 degrees downstream of the
igniter and near the periphery of the throat where the ultraviolet radiation is at a maximum. (see
figures 4 and 5).
4.
Having determined an approximate location for the sight tube, cut a clearance hole for a 2 inch
pipe through the burner plate. If register vanes interfere with the desired line-of-sight, the inter-
fering vane(s) should be trimmed to assure an unobstructed viewing path at all firing levels.
5.
Mount scanner sight pipe by either:
— Centering a swivel mount, P/N 60-1664-3 (NPT) or 60-1664-4 (BSP) over the hole and
installing the sight pipe on the swivel mount, or
— Inserting the end of the sight pipe into the hole, aligning the pipe to the desired viewing
angle and tack welding. Welding must be adequate to temporarily support the weight of the
installed scanner. The sight pipe should be arranged to slant downward so that dirt and dust
will not collect in it.
6.
When a satisfactory sighting position has been confirmed by an operating test, (see section on
alignment), the sight pipe should either be firmly welded in place or, if the swivel mount is used,
the ball position should be secured by tightening the three hex head cap screws located on the
swivel mount ring. In certain older style swivel mounts, tack welding may be required.
PRIMARY
COMBUSTION
ZONE
AIR REGISTER
BLADES
SCANNER
LINE OF
SIGHT
BURNER
THROAT
FLAME
ENVELOPE
BURNER
CENTER LINE
BASE
IGNITOR
SCANNER
MAIN
BURNER
CCW ROTATION
IGNITOR
SCANNER
MAIN
CW ROTATION
BURNER
