US1910316A - Method of eliminating soot - Google Patents

Description

May '23, 1933.

R. A. BLUNT METHOD OF ELIMINATING SOOT Filed March 51, 1927 fl-za 2; 15 E 117%;

J] 14 n I n n n 16 INVENTOR #qyden 14. 6/0/77.

BY WT m ATTORNEY Patented May 23, 1933 UNITED STATES} ROYDEN A. BLUNT, or BALTIMORE; MARYLAND METHOD OF ELIMINATING SOO'I" Application filed March 31, 1927. Serial No. 180,050.

This invention relates to the art of fuel burners and more specifically to a method of and apparatus for removing deposits of soot in gas producer lines.

It has heretofore been customary to remove accumulations of soot by raking out or blowing out with steam, but both of these methods are objectionable, since raking out is difficult and expensive and still leaves the ultimate elimination of the soot to be pro vided for, and blowing out with steam discharges the soot into the atmosphere unburned with a consequent pollution of the surrounding territory.

By my present invention I introduce a large volume of low pressure air which burns the soot progressivelyfrom the point of intake of the blower air up to the end of the line, and results in the combustion of substantially all of the soot by the time the top of the stack is reached. During this operation a very high heat is generated and it is necessary to carefully regulate the volume of air so as to provide sufficient oxygen'for complete combustion, and at the same time regulate the pressure so as not to propel the soot into the atmosphere unburned, and not to generate such a great degree of heat that the metal and refractory parts of the sys tem will be damaged.

It is therefore an object of this'invention to provide a new and improved method of soot elimination.

It is another object of this invention to provide an apparatus for carrying out this method. r

It is also an object of this invention to perform these operations without discharging the soot into the atmosphere unburned and 0 without damaging the gasma-in. g

It is another object of my invention to perform the burning out operation without shutting down the operation of the furnaces or lehrs which are ordinarily heated by :the

5 producer gas, and to cool the main'a's the burning out is being effected.

lVith the above and other objects in view, which will be apparent as the description proceeds, I have set forth my invention in the following specification taken inconnection with the accompanying drawing, in which:- I

Fig. 1 is a diagrammatic plan view of my improved apparatus, and

Fig. 2 is a vertical section through a portion' of my apparatus on the line 2-2 of Fig. 1, on an enlarged scale.

My invention is particularly adapted for the. removal of products of combustion from producer gas mains. In these there is a heavy accumulation of soot, which is of a loose, light and flaky nature, so that it is easily blown out into the atmosphere if any considerable pressure is applied to it. This accumulation is so rapid that after operation for a week the mains are often filled with it to one-third of their capacity, thus impairing the efficiency of the gas main and making it necessary to remove'this accumulation. I- have discovered that this can be done, without discharging thesoot into the atmosphere, and without damaging the line, by using a large volume of low pressure air. While the Volume and pressure vary for difierent installations, and especially with the length thereof, I have found that a volume of from fortylto fifty thousand cubic feet of air per minute, and a pressure of three-fourths of an inch of water,-aresatisfactory for most purposes, and particularly for installations using mains of 6 to 8 feet diameter and 700 or 800 feet in length with several outlets therefrom. If a pressure greater than one and one-half inchesof water is used, the temperature which is'generated by the com 8 bustion of the soot is ordinarily so great that the metal and refractory parts of the producer lines are damaged;

. Referring to the accompanying drawing, Ihave illustrated therein the general arrangement-of aproducer gas main 10 and a series of furnaces 11 and lehrs 12 heated by the producer gas conveyedby said main. Each of the furnaces and lehrs is provided with a cut-off damper 13, to prevent communication between them and the main at predetermined.times,and each of the furnacesand lehrs is 'also provided with gas or oil burners 14 for heating them independent ly of the producer gas 1 during the burningburned out, with the resut out period. At suitable points in the line, stacks 15 communicate with the atmosphere and each of these stacks is preferably provided with a cut-off damper 16 adjacent to its connection with the main 10. The producer gas is supplied to the main at 17 from any suitable gas producer, or gas producers (not shown), and the main may be shut off from the latter by a damper 18.

The air is supplied by a blower fan 21, of any well known type capable of handling a large volume of low pressure air, which is connected with one end of the producer main. 1

When a sufficient amount of loose soot has accumulated in the latter to warrant its removal, the dampers communicating with the producers, furnaces and lehrs are closed, the dampers communicating with the stacks are either left completely open or partially th-rottled, as will be explained later, and the blower is started at such arate that it will deliver from 40,000 to 50,000cubic feet of air per minute at a pressure of approximately of an inch to 1 inches of water, The

incoming air starts the hot soot rolling along the main and the combustion begins to take place without the application of any enternal heat. This generates additional heat and the burning out is progressive throughout the main, succeeding portions of the incoming air furnishing the necessary oxygen for the combustion of'the soot contained in succeeding portions of themain and eifectin'gv a cooling of those portions of the main from which the soot has reviously been that substantially' all of the soot in the main is gradually burned before it can emerge from the stack. Inasmuch as the sootis, practically pure carbon, no residue is left,

A-sufficient volume of air must be introduced tolcarry all the soot along withtit me toprovide sufiicient oxygen to promote the combustion of all of the soot. At the same time the air pressure must: be low enough to prevent blowing the loose, flaky soot into the atmosphere unburned. The volume of air introduced can be controlled at the blow er by regulating its speed and by'throttling it by a slide control 22, T This regulation of'the volume of air at the blower also affects the pressure devel-- oped in the line. Consequently, if too great a pressure is being developed, it can be re duced bypartially throttling the blower; A similar reduction in the pressure can also be accomplished by opening the stack dampers. H a V The temperature developed in the main increases with the volume and pressure, and with the length of the main, and is highest at the end farthest from the inlet of the blower air. It hasbeen-foun'd that in along main a pressur-e1of asmuch as 1 inches of water, coupled with a volume of from 40,000 to 50,000 cubic feet of air per minute, will develop a temperature of approximately 2800 F., which is sufliciently high to cause gradual deterioration of the gas main by opening up seams therein, by burning the metal framework, and by breaking down the efficiency of the refractory parts. I have therefore found it desirable, when using the above volume of air in a long main, such as that described above and illustratedherein, to reduce the pressure to of an inch of water, and I have found that this ean be most effectively done by throttling the blower and leaving the stack dampers wide open.- Under these conditions-a'temp'erature of from 2=l00 to 2500 F J is developedat the hottest period.

I have found that in such installation the soot can be effectively removed by burning out themain in the manner indicated here-- in for a period of about 45 minutes per week.- During the burning out it is not necessary toshut down the operation of the furnaces and lehrswhich are normally heated by the producer gas, as their operation can be continued by lighting the gas or oil burners 1 f.

I have also foundcthat when excessive temperatures are developed at various points in the line, these temperatures can be lowered by injecting small amounts of steam into that portion of the line, as by the nozzles This steam acts as a cooling agent and absorbs the excess sensible heat."

In Fig. 2'1 have shown the construction of one form of gas producer. main. This consists of a steel shell 31, immediately inside of which is placed a lining of sil-o cel bricks 32, and inside of the latter is placed a lin ing of fire bricks 33 The sil-o cel bricks and the refractory bricks are each luted to gether in the regular manner.

By the termhot soot, as used herein, I mean that the soot is at the temperature of its'ignition. V I V I c I From the above description it will be apparent that I have solved the difiicultproblem of disposing of'loos'esoot, whichiisan inherent disadvantage in the use of pro ducer gas, without discharging this soot into the atmosphere unburned, thus making it; possible for'industries located in cities, ,aswell as those in rural districts, to avail themselves of this cheap sourceVo-f fuel without conflict with the municipal regulations on soot disposal, andv that the burning out roporation may be carried on simultaneously with nornial production in the factory in which the burning out is to beeffected, thus resulting in a considerable saving of time andmoneyr It will also be obvious that IIIYlHVGBlll'JlOH can be applied with equal efficiency to shorterpandless complicated mains than that illustrated and described herein, and that the connections and arrangement of the Various parts of my apparatus may be varied in many ways Within the scope of the following claims.

I claim:

1. The method of eliminating loose hot soot at the temperature of ignition in the presence of air from gas producer mains, which comprises blowing into the main over 40,000 cubic feet of air per minute at a pressure of less than 2 inches of Water, and thereby burning the soot Within the main Without discharging it into the atmosphere.

2. The method of eliminating loose hot soot at the temperature of ignition in the presence of air from gas producer mains, which comprises blowing into the main from 40,000 to 50,000 cubic feet of air per minute at a pressure of approximately of an inch of Water, and thereby burning the soot Within the main Without discharging it into the atmosphere.

ROYDEN A. BLUNT.

Images