Middleby Marshall PS200 series - Manual (Page 13)

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IV. OVEN CAPACITY
Oven capacity is generally not a service issue. However,
when reporting a service problem, customers may use terms
relating to capacity, such as bake time, belt time, time of
delivery, etc. This information is provided as a reference for
understanding these terms.
A. Conveyor Speed and Bake Time
Middleby Marshall conveyor ovens display the Conveyor
Speed on the Thumbwheel (or on the display of the
Digital Speed Controller, as appropriate for the oven
model). Conveyor Speed is also called Bake Time.
Conveyor Speed (Bake Time) is a leading edge to lead-
ing edge measurement. That is, it is the elapsed time
from the leading edge of the product entering the bake
chamber to the leading edge of the product leaving the
bake chamber. See Figure 9.
Figure 9 - Conveyor Speed (Bake Time)
Conveyor Speed
(Bake TIme)
Direction of
Conveyor Travel Leading edge
of product
Figure 10 - Belt Time
Belt Time
Direction of
Conveyor Travel
Trailing edge
of product
B. Belt Time
Belt Time is a measurement used by several custom-
ers. It is a trailing edge to trailing edge measurement.
That is, it is the elapsed time from the trailing edge of
the product entering the bake chamber to the trailing
edge of the product leaving the bake chamber. See
Figure 10.
Note that belt time is equal in length to conveyor speed
(bake time), although the time is measured during a
different period of the baking process.
C. Time of Delivery (TOD)
Time of delivery (TOD) is a leading edge to trailing edge
measurement. That is, it is the elapsed time from when
the leading edge of the product enters the bake cham-
ber to when the trailing edge of the product leaves the
bake chamber. See Figure 11.
Figure 11 - Time of Delivery
Time of Delivery
Direction of
Conveyor Travel
Leading edge
of product
Trailing edge of
product
D. Formulas for Determining Time of Delivery (TOD) and Oven Capacity per Hour
1. Time of Delivery (TOD)
Time of Delivery (TOD) = x (Bake Chamber Length + Product Diameter)
Example: PS570S Oven, 7:00 Bake Time, 16” Product Diameter = x (70” + 16”) = 8.6 mins. (8:36)
2. Oven Capacity/Hour
Oven Capacity/Hour = x
Example: PS570S Oven, 7:00 Bake Time, 16” Product Diameter = x 6.98 = 75 pizzas/hr.
Conveyor Speed
Bake Chamber Length
7 mins.
70”
(Bake Chamber Length + Product Diameter) x Bake Chamber Depth
Product Diameter²
60 min./hr.
TOD
(70” + 16”) x 32”
256 in.²
SECTION 2 - AIR FLOW AND HEAT TRANSFER