Table Of ContentPETROLEUM fuel burners for the generation of
RADIANT ENERGY FOR FROST CONTROL
By
Francis Jefferson Hassler
A THESIS
Submitted to the School of Graduate Studies of Michigan
State College of A griculture and Applied Science
in p a rtia l fulfillm ent of the requirements
fo r the degree of
DOCTOR OF PHILOSOPHY
Department of A gricultural Engineering
1950
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TABLE OF CONTENTS
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INTR QDUGTI Q'J------------------------------------------- ................................- 1
Review of the Weed and Ilethods for Frost Control- 2
Wature of the problem ------------------------------------- 2
Radiation-type fro st --------------------------------------- 2
ilethods used for the protection of
vegetation from fro st damage ------------------------- 5
Preliminary te sts a t Michigan State College- 7
Theory of the Emission, Transmission, and
Absorption of Infrared or Thermal Radiation -------- 11
Q uantitative lav/s for blackbody radiation — 14
Transmission of infrared radiation --------------- 20
Absorption of radiation by vegetation ---------- 22
Previous Work and Present Status of the
U tilization of Infrared Radiant Energy for the
Protection of Vegetation from Frost Damage ---------- 24
Original investigations ---------------------------------- 24
Studies to develop a high capacity non
powered liquid petroleum fuel b u rn e r----------- 27
Reflector studies -------------------------------------------- 29
EXPERIMENTAL WORK —--------------- 33
Studies to Improve the F rostguard ------------------------- 34
A study of liquid petroleum f u e l s ----------------- 34
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An analysis of the burning characteristics
of the F rostguard-------------------------------------------- 41
Experimental tria ls to improve
the F rostguard------------------------------------------------- 45
The original burner— ----------------------------- 45
F irst m odification---------------------------------- 48
Second m odification -------------------------------- 50
Third m o dification ---------------------------------- 52
Discussion of r e s u lt s ------------------------------------- 55
Studies to Develop a High Capacity Non-
powered Liquid Petroleum Fuel Burner ---------------------- 58
O bjective---------------------------------------------------------- 59
Procedure---------------------------------------------------------- 61
Existing non-powered liquid
petroleum fuel burners — --------------------------------- 66
F irst tr ia l b u rn e r------------------------------------------- 68
Second tr ia l burner ----------------------------------------- 76
Third tr ia l b u rn e r------------------------------------------- 79
Discussion of r e s u lt s ------------------------------------- 81
Development of a Liquified Petroleum Gas Burner
for the Generation of Radiant Energy for
Frost C o n tro l------------------------------------------------------------ 83
O bjective---------------------------------------------------------- 35
Procedure---------------------------------------------------------- 86
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Discussion of resu lts ------------------------------------- 89
Summary----------------------------------------------------------------------- 97
C onclusions----------------------------------------------------------------- 101
LITERATURE CITED -------------------------------------- 103
ACKW CWLEDGIaENTS - ------------- -1 0 6
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LIST OF FIGURES
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Fig. 1 A comparison of the radiant energy
d istrib u tio n from an oxidized steel surface
with a theoretical blackbody--------------------------- 15
Fig. 2 Spectral energy d istrib u tio n as a function
of tem perature--------------------------------------------------- 17
Fig. 3 Total radiation as a function of temperature- 19
Fig. 4 Diagram showing the principle of the inverse
square lav; of radiation distribution from a
point source of o rig in ------------------------------------- 21
Fig. 5 The effect of comparatively large reflecto rs
on the d istribution of radiation from a
straight surface ------------------------------------------------ 30
Fig. 6 Radiant energy d istrib u tio n from the
F rostguard---------------------------------------------------------- 31
Fig. 7 The Evans F rostg uard----------------------------------------- 55
Fig. 8 Pressure heat-vaporizing type kerosene burner 42
Fig. 9 The arrangement of the burner and combustion
chamber of the Evans F rostguard---------------------- 46
Fig. 10 Illu stratin g the f ir s t m odification of the
F rostguard---------------------------------------------------------- 49
Fig. 11 Illu stratin g the second m odification of the
F rostguard---------------------------------------------------------- 51
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Fig. 12 Showing the position of the ceramic m aterial
to stab ilize the burner for the Frostguard — 54
Fig. 13 Arrangement for testing non-powered liquid
petroleum b u rn e rs---------------------------------------------- 63
Fig. 14- Apparatus for measuring the radiant energy
d istrib u tio n from heater u n its ------------------------ 65
Fig. 15 Open pot b u rn e rs------------------------------------------------ 67
Fig. 16 Burning characteristics and radiant energy
d istrib u tio n for the United Stove Company
Orchard Heater --------------------------------------------------- 69
Fig. 17 Burning characteristics and radiant energy
d istrib u tio n for an open-topped container ---- 70
Fig. 18 The Return-stack Orchard Heater developed at
the University of C a lifo rn ia --------------------------- 71
Fig. 19 Burning ch aracteristics and radiant energy
d istrib u tio n for the Return-stack Orchard
H e a te r----------------------------------------------------------------- 72
Fig. 20 F irst T rial B u rn er-------------------------------------------- 73
Fig. 21 Burning ch aracteristics and radiant energy
d istrib u tio n for the F irst T rial Burner -------- 75
Fig. 22 Second Trial B u rn er------------------------------------------ 76
Fig. 23 Burning ch aracteristics and radiant energy
d istrib u tio n fo r the Second T rial Burner ------ 78
Fig. 24 Third T rial B u rn er-------------------------------------------- 80
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Fig. 25 Experimental propane burner units - - --------------- 90
Fig. 26 Burning characteristics and radiant energy
d istrib u tio n for the 60° type propane burner- 91
Fig. 27 Burning ch aracteristics and radiant energy
d istrib u tio n for the 32° type propane burner- 92
1
INTRODUCTION
2
Review of Reed and Methods of Frost Conti ol
Nature of the problem
One of the main hazards to fru it and truck ci ops is
radiation-type fro st damage (26). This damage in ckludes la te
m aturity of crops (due to la te planting), poor qua lity and
quantity, and in some instances a to ta l lo ss of pi oduce.
In the United S tates, losses because of fro st dam ge are
more pronounced in states such as Florida and Cal if ornia
where the citru s crop makes up intensive or highly -valued
agriculture. The same is true for states that grccw truck
crops and fru it orchards extensively. Michigan re presents
th is type of agriculture and the annual fro st damsj ge in the
State of Michigan is estim ated to range from ten \ o twenty
m illion d ollars (6).
Radiation-type fro st
The earth receives its heat from the sun in t he form
of radiant energy. This energy is absorbed by plad nts and
transformed into sensible heat. At the same time that heat
is being received, plants are radiating a part of th is heat
back toward the sky. However, there is a net gair l on the
part of the plants during a twenty-four hour peric d. This
condition is brought about by the blanketing effe ctt of the
3
atmosphere on the earth, for the energy of the sun is emitted
in short wave-length radiation which penetrates the atmosphere
of the earth with l i t t l e loss, while the plants, having ab
sorbed th is energy, emit i t in long wave-length radiation
which is readily absorbed by the atmosphere and thereby resu lts
in heat being added to the atmosphere; which at the same time
decreases the net loss from the earth and plants. This
implies th at, void of its atmosphere, the earth would become
extremely hot during the day and extremely cold during the
night which corresponds to the teaching of physicists in
general. Therefore, the atmosphere serves as a trap whereby
the earth retains sufficient heat to carry it through the
night.
The condition of the atmosphere, then, w ill greatly
influence the net amount of heat gained by plants in any one
period of time. For example, the absorbing characteristics
of the a ir become more pronounced as the absolute humidity
increases. Conversely, if there is l i t t l e humidity in the
a ir, as on a clear night, the plants rapidly lose th e ir heat.
Radiation-type fro st is common during the early and
la te parts of the growing season. Its formation can be ex
plained as follows on the theory of heat tran sfer. To set
the stage for th is type of freeze, i t is required that there
