An outline of the principal features of the Petrocarb Pneumatic Feeding System is given. Early development and various commercial applications are included. It is concluded that the Petrocarb Injection System is capable of feeding dry solids into most of the processes being developed for utilizing coal

Reintjes, H.

English

NASA Technical Reports Server

THE PETROCARB PNEUMATIC FEEDING 
SYSTEM- -A PROVEN METHOD FOR 
FEEDING PARTICULATE SOLIDS AT 
CONTROLLED RATES 
H. Reintjes  
Pe t  rocarb,  Inc. 
New York, New York 
https://ntrs.nasa.gov/search.jsp?R=19780005300 2020-03-20T12:33:45+00:00Z
P E T R 0 C A R B PNEWFIC FEEDING SYSTEM - A PROVEN METHOD 
by Harold Reintjes, Presiaent 
PETROCARB, INC. 
New York, New York 
ABSTRACT 
The Petrocarb Injection System is a pneumatic feeding system having proven 
capability for feeding s~lids at controlled rates into processes which operate 
up to 60 atnospheres pressure. A single system can be provided which can feed 
a single or multiple feed points with substantially equal distribution between 
the various feed lines. The syst~rm is completely automatic and is normally 
supplied with a solids rate control system. 
A summary description of the system elements is presented together with an out- 
line .-f the principal features of the system. 
The paper refers to early development which started approximately twenty years 
ago and outlines various commercial applications. 
The history of successful applications and experience lezds to the conclusion 
that the Pecrocarb Injection System IS capable of feeding dry solids into most 
of the processes being developed for utilizing coal. 
Petrocarb has supplied Injectors for feeding pzrticulate solids at controlled 
rates since 1959. Most applications of this early technology were in the iron 
making industry where hundreds of units are in use today on a world-wide basis. 
Some oi the basic requirements for the feeders used in these applications are 
that they: 
a) be capable of supplying constant and reproducible flow rates 
for short intervals of a few minutes duration 
b) have the ability to feed against hack pressure such as developed 
by a head of several feed of molten iron 
c) be available in a range of sizes and be capable of feeding solids 
at rates from a few pounds per minute to several tons per hour 
d) can be easily and quickly stopped and starced 
e) use high solids to gas ratios in order to conserve ~xpensive gases 
such as argon and to minimize metal splash from submerged lances. 
Technological developments of the early 1960's prompted the introduction 
of more sophisticated custom desiged systems capable a £  feeding against 
pressures of over 60 atmospheres, such as may be encount.ered in coal gasifiers 
and combustors, at rates up to about 150 tons per hour in i t  single, shop fnbri- 
cated feed system. Early applications r::qdired only a single feed ltne but as 
technology was advanced, units having mtlleiple lines, feeding continuously, 
were developed and comnercialized. A brief description of a basic Petrocarb 
Coal Injection System, together with some applications, follows. 
2. DESCRIPTTQN OF PETROCARB INJECTI3N SYSTEM 
Please refer to Figure No. 1, which is a simplified flow diagram of a typical 
system for feeding against intermediate pressures. Modifications of this 
system are sometimes used depending on the particular application. The 
Petrocarb Injection System provides continuous and automatic injection of 
prepared solids into a process reactor at any designated rate, distributed 
uniformly ammg the feed lines. The Primary Injector is the heart of the 
system. This unit is a pressure vessel of proprietary design with multiple 
feed outlets, one for each injection nozzle of the reactor. Each of the 
multiple feed outlets from the Primary Injector has an individual injection 
air line, equipped with both gas and solids flow indicating instruments. . a 
After initial adjustments are completed, substantially equal quantities of 3 ", 
solids will be delivered to each nozzle. 
:? 
!. 
.a 
The total injection rate is a direct function of the differential pressure 
between the continuously pressurized Primary Injector and the point of delivery 
I(. 
of the solids. The characteristic is stable, smooth, and repeatable, thereby i!: 
providing a means of controlling solids feed rate without introducing variable $ 
-3 
restrictions or other equipment in the solids stream, with their attendant 
' ~ i  .t. 
problems. '1'k.e Primary Injector is nounted on load cells which provide necessary 
signals for a weight rate control system. In autovatic mode, the desired feed 
rate is autornaticslly maintained as set by the operator at the control panel. 
j 
$6. 
Thz o?erator can override the weight rate control action by placing the system 2.4 
..d: 
in manual mode and setting the differential pressure ccntroller set-point  nua ally. - 8  
In same installat3.ons the more sophisticated provision for automatic resettiug of ;a 
.,i"U the rare control instrument is unnecessary. 
-:%* t+-. 
- d' <* 4:*' 
Above the Primary Injector is the Storage Injector, which automatically replenishes ,W' t 
the solids fed from the Primary Injector without interrupting or disturbing the ?$$$ . .W 
injection process. This functions as a lock hopper. Lock hoppers, traditionally, . "* 
., . 
have been somewhat unreliable for the same reasons that one cannot assume that a 
-8 
'9' 
vessel or storage bin, provided with an inlet and outlet, assures that solids % &- 
'. $ 
will flow from the vessel when the outlet valve is opened. , ** ,. j 
"Pi".. 2; 
Our Storage Injector overcomes such problems, and is an integral part of the (1 :
,:p. 
system. When the Storage Injector is emptied of material, it is automatically ;i" 
*%. depressurized and refilled either by a Feed Injector located at grade level 
. ?=., *I, 
below a prepared materials storage bin, or from an elevated storage bin. i.l 
When a Feed Injector is used, material from the storage bin is fed end conveyed ,*.! , 
. u to a receiver-filter above the Storage Injector where the solids and conveying 
gas are separated. Solids flow is by gravity into the Storage Injector and the :.$ 
filtered transport gas is discharged to the atmosphere. t4 #- 
'The size of the solids batch, mechanical equipment, valves, and time 
increment for each functio~ are all designed and coordinated to provide 
feed to the process, up to the maximum design rate, while raintaining a 
reserve capability in the Primary Injector. All operations are automatic, 
being supervised and controlled by a specially designed log2.c qystem. 
Solids flow in any feed line can be stopped or started by the manual 
operation of a remote switch for that line. Also the flow can be stopped 
automatically in an individual line or any desired multiple thereof by 
programed process requirements or system safeguards. 
A section from a strip chart recorder shwing the net weight cf coal being 
fed frm a Primary Injector mounted on load cells, with the system functioning 
in the equivalent of the manual mode, is shown in Figure 2. Note the smooth 
line with only one irregularity which was caused by autamatic stopping of coai 
feed for a brief period because of a process requirement. The feed rate can 
he comnanded to follow a downstream process signal such as temperature, bed 
level, or production rate. 
3. APPLICATIONS 
Let ss now look at some of the applications of the Petrocarb Injection System 
where the process application demands continuous feed under automatic control. 
Petrocarb pioneered the first commercial sized blast furnace coal injectbon 
system at the Hanna Furnace Corporation No. 2 Furnace in 1961. This was a 
merchant iron plant and economics unfortunately dictated the closing own of 
Strassburger et a1 in 1362. 
4 this furnace. The coal injection operation was described in a paper 1 by 
In 1963 the Netional Coal Board in England purchased a Petrocarb Coal Injection 
System which was installed at the Stanton & Staveley Ltd. No. 5 Blast Furnace. 
This system was operated successfully for about three years and was the subject 
of a p5fze winning paper Ly E. M. Slmmers at the AIME Iron Making Conference in 
1964. - The installation and operation were technically very successful, but 
unfavorable economics resulting from tllc relative costs of coal and fuel oil at 
the time, plus the discovery of oil in the North Sea, prompted the discontinired 
operation of the coal injection system and ab=donment of a plan to install coal 
injection systems on blast furnaces throughout the U.K. The injection unit was 
dismw.tled and moved to Leatherhead where it has been used in test operations by 
National Research Development Corporation, London, England, for feeding coal in 
a pressurized fluid bed combustor experimental program. A portion of this work 
was sponsored by the U.S. Office of Coal Research and the British C 1 Utilization 31 Research Association Ltd. (BCURA) and is covered in an OCR Report. - 
Since 1967 two zinc slag fuming furnaces have been in substantially continuous 
operation at Port Pirie, South Australia, using the Petrocarb Injection System. 
The furnaces require dependable feeding of pulverized coal which serves a dual 
role of providing heat, and acting as a reducing agent in the process. Each of 
these two furnaces has thirty (30) submerged tuyeres which are fed with coal 
from a single injection unit (one for each furnace). The most difficult p-.ablem 
in the design 02 this system was to cope with the feed rate of three to 
five pounds per minute in each of the thirty lines. A larger system would 
have been less difficult to design. Thi operation was the subject of a t / paper by I. D. Brett presented in 1968. - 
Petrocarb's Injection System is used in a modern copper-nickel plant located 
in Botswana which uses the Outokumpu Flash Smelting Process. Pulvericed coal 
is being fed to multiple burners to produce heat for the process. It is 
essential that the coal injection equipment used to feed coal into the burners 
provide smooth, steady flow and uniform distribution among the burners. In 
this facility, the coal feed rate is automatically controlled by a single 
rate-setting on the control panel. The rate control instrumentation auto- 
matically adjusts the instrument primarily responsible for the delivery rate 
of coal. The net weight of coal in the Primary Injector is continuousiy recorded 
on a strip-chart so that the operator has visual evidence of the performance of 
the feeding system. 
A copper and nickel smelter complex being constructed in Russia, which also 
uses the Outokmpu Flash Smelting Process, will utilize Petrocarb Injection 
Systems for feeding pulverized coal to the process. This application i 
interesting in that the coal is to be used as a reducing agent for converting 
sulfur dioxide in the high temperature exit gas from each of two smelters (one 
copper and the other nickel) to elemental sulfur which will be condensed and 
recovered in waste heat boilers. 
The application of Petroccrb Injectiou Units for high feed rates has beel, 'ully 
demonstrated in a multiple unit i.nstallation in Venezuela where very abrasive 
iron ore is fed at the rate of about 77 tons per hour in each unit against a 
pressure of three atmospheres. As a result of this installation, hardware has 
been developed which hes good abrasion resistance. Reference is made to the 
units in Venezuela AS the reason for the selection of the Petrocarb System by 
The Lumnus Company for use on the Synthane Coal G~~ification Project in a paper 
5 1 by R. T. Whitehead in 1974. - 
The use of coal as a replacement for oil and gas in the production of electric 
parer, and the production of pipe-line gas from coal, i~ a subject with which 
we are all concerned. Many different processes are being investigated. While 
the basic approach to solving the problems associated with each process is quite 
-~aried, there is one conmaon denominator - each must have a dependable coal 
feeding system. 
Petrocarb is involved with major pilot projects as the supplier of solids 
feeders dealing with 
a \  Pressurized fluid bed combustor development, 
b) :fHD reactor development, and 
c) Coal gasification 
An example of the latter is the Synthane Process for high pressure coal 
gasification being developed by the Pittsburgh Engineering Research Center 
6; (ERDA). This application 1s the subject af a paper by Mr. Zobert Lewis et al. - 
With reference to pressurized fluid bed combustor projects, Petrocarb is 
nupplying coal and dolomite feed systems to Curtiss-Wright 011 its c-lrrent 
contract with EP'SA, and has been awarded a contract to supply the ,oal 
dolomite fee?.ng system for the Grimethotpe Project in England whlch is 
being co- ponsored by EKDA, the National Coal Board of England, and West 
77 Gennany. - 
4. STATUS OF FEEDER DEVELOPMENT 
Petrocarb's current position is that it can provide dependable feed sjstems 
uiing existing knowledge and equipment components without large scale development 
work. We believe our feeder designs will be able to keep up with any realistic 
requirements of the coal utilization program without large scale government 
funding. These systems can re..,ily be scaled up to large throughputs and in- 
corporate components which for the most part are currently being ,nnufactured 
or utilize proven designs. C-rtainly there is a requirement for specialized 
know-how in the design of ,L dependable feeding system. Suc'l i ~ . r  ors as solids 
to gas ratlas, feed rates, reactor pressure, particle size aril particle size 
distribution, flow chara~ieristics of the solids, and moisture content, all 
enter into the design of a dependable feed system. Furthermore there are no 
known published data which could be utilized to tr.z?i- all I£ such variables 
and permit one to design a successful installation. Fortunately, Petrocarb's 
experienct (as partially related above) plus a considerable amount of development 
work carried out in its own test facility permits it to confidently claim the 
?osition as stated above. 
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1. Strassburger, J.H. , E.G. Ostrawski, and J.R. Diete, "Solids Fuel 
Injection At The Hsnna Furnace Corporation", Blast Furnace, Coke Oven, 
and Raw Material Conference, A M ,  New York, 1962. 
2. Srnrmers, E.M., "Engineering and Design Considerations of Coal Injection", 
AIME 23rd Conference, Ironmaking 1964. 
3. National Research Development Corporation,  ond don, England (NRDC), 
"Pressurised Fluidised Bed Combustion, 2 6 D Report No. 85, Interim 
No. 1" , for the Off ice of Coal Research (OCR) , U. S. Department of 
the Interior 1974. 
4. Brett, I. D. , "Puliierized Coal Injection in Slag Fuming Furnaces at 
Port Pirie, South Australia", Conference on Combi~stion and Combustion 
Equipment, Australian Institute of Fuel 1968. 
5. Whitehead, Richard T., "The Synthane Coal Gasification Prccess of Coal 
Feeding and Char Removal Systems", AIChE Annual Meeting 1974. 
6. Lewis, R., Et al, "Coal Pressurization and Feeding, Use of a Lock Hopper 
System", for ERDA 1977. 
7. National Coal Board, London, England, "International Coal Combustion 
Project - Equipment Ordered: Start on Prelininary Site Work", Yews 
Release February 1977. 


The Petrocarb pneumatic feeding system: A proven method for feeding particulate solids at controlled rates

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