US1728720A - Process and apparatus for utilizing the heat of the waste gases of alternately-working gas generators and that of the produced gas - Google Patents

Description

Sept. 17, 1929. BREISIG 1,728,720

PROCESS AND APPARATUS FOR UTILIZING THE HEAT 0? THE WASTE GASES OF ALTERNATELY WORKING GAS GENERATORS AND THAT OF THE PRODUCED GAS Filed June 11, 1926 INWSNTO Q Patented Sept. 17, 1929 UNITED STATES ALBERT BBEISIG, OF VIENNA, AUSTRIA PROCESS AND APPARATUS FOR UTILIZING THE HEAT OF THE WASTE GASES OI ALTEBNATELY-WOBKING GAS GENERATORS AND THAT OF THE PRODUCED GAS Application filed June 11, 1926, Serial No. 115,895, and in Austria June 18, 1925.

In the manufacture of water gas or of .a mixture of water gas and coal (distillation) gas by means of alternately working generators. that is to say such. in the operation of which a period of blowing up, called the gImWaItei-nates with a period of gas making, called the run, onlypart of the entire amount of heat generated during the blow is accumulated in the coke and thus directly utilized in the subsequent run so that the gases'will escape from the generator with a high temperature and containing a considerable amountof heat. This surplus of heat is utilized for the generation and for the sn- 1 perheating of the steam required in the gas making process either by burning the said gases in a heat accumulator. which then serves for generating and superheat-ing the steam, or by leading them into a boiler constructed for the utilization of waste heat. By neither of these two ways is a perfect and economical utilization of the heat possible. As the time, during-which the blowing is efl'ected, amounts, to only about one fifth of the entire time of operation. waste heat boilers capable of utilizing during these short blowing periods the entire heat contained in the waste gases should have such large heatin surfaces as is not practicable. If on the otiier hand a heat accumulator is employed, in which the steam is superheated, the waste gases will escape therefrom with a considerably great content of heat, but at a temperature of about 300 to 500 (3., which in the most cases is too low for allowing further economical utilization thereof. The same inconvenience also arises. if the accumulator not only serves for super-heating the steam, but. also for generating it.

On the other hand this latter method has the advantage ofautomatically adjusting to a certain extent theamount of the generated steam according to the conditions, under which the generator works. Accumulator-S of this kindmay for instance be of the type, in which the hot gases pass'through a body of superposed iron bars. The total surface and weight of this body can be chosen such that the iron bars at the given temperature and speed of the gases take up just as much heat as is required for the generation of steam during the subsequent period of run. If under such circumstances by inadvertance of the operator or owing to an alteration of the resistances in the coke column or in the blower duct an insuflicient amount of air is blown in, there will be less heat accumulated in the iron body and for this reason also less steam will be generated. Consequently less steam is fed into the generator, which in such case had not been heated up to an adequate that is to say regular extent, so that finally it will assume its regular temperature and in spite of the deficient operation will yield good gas. If the blowing is eflected excessively, more steam is generated and introduced into the generator heated up too much, so that also in this case it will reassume its regular temperature. As is seen. by the use of an accumulator of the said type advantages are 7 obtained in respect of the quality of the generated gas and in respect of fuel consumption. which advantages are not attainable by employing steam from a boiler. The admission of steam from a boiler is as a rule meas- 7 ured by the time of its flow, so that, if the vapor tension is constant, there is always the same amount of steam fed into the generator without any consideration of the changing state of the latter. Therefore, if the tem rature of the generator is too low or too igh, there will no accommodation, that is to say adjustment of the amount of steam according to the temperature of the generator take place. 1 Conseguently in aiming at a perfect utilization o the heat of the gases in questionit appears desirable to assure the described automatic adjustment by maintaining the heat accumulator. serving as vaporizer.

According to the present invention this is obtained by leading only part of the gases,

which escape from the bafile brickwork of the recuperator serving during the .run for superheating the steam, into the vaporizer, this part being chosen such, that it, is suflicient for generating the steam required for the run, whilst the remainder of the gases in question is branched oh and conducted to a waste heat boiler. Thus it is obtained, that vantage is not given in the known arrang ment with a boiler being mounted after 0.1; behind the accumulator, as in the latter case the gases escaping from the vaporizer are cooled down to a temperature of 300 to In the drawing a gas generating plant adapted for carrying out the invention is illustrated by way of example.

A is the generator, into which fuel is introduced through B and air through C. The gases produced during the blow leave the generator through the pipe D and pass into the bafile brickwork of the recuperator E, where they are completely burnt, additional air being admitted at F. Of the hot combustion gases escaping from the bafile brick work ofthe recuperator E one part enters the vaporizer G and from there passes through the opened stack valve H into the open air. The other part is through the valve J conducted into a waste heat boiler M, from which it escapes through a separate chimney T. In connection with the gate valves H and Y J preferably also throttle valves K and L are mounted in order to allow adjustment of the division of the gases to be divided between the vaporizer. and the boiler.

During the run the valves J, H and the air valves are closed. Water is injected into the vaporizer at N, the generated'steam is superheated by the baflie brickwork of the recuperatorE and passes through the pipe D 'into the generator A. The enerated water gas flows through the duct into the smoke tubes Roi the waste heat boiler and is from there led ofi to P.

Waste heat boilers as illustrated in the drawing, which are heated by the waste gases passing along, and around the water tubes W as well as by the generated gas are known already. Their use in the present process involves special advantages inasmuch, as the working is rendered much more regular than had hitherto been possible by the method of introducing the entire quantity of waste gases leavin the recuperator E into the boiler. In t is known method of operating the periodical supply of heat by the waste gases was relatively very high in comparison with that of the heat supply by the generated water gas." The generation of steam therefore took place rather irregularlv' By the present method the amountof heat supplied by the waste gases is decreased and thus more equalled with that furnished by the generated water gas, a more uniform generation of steainbeing thus assured.

What I claim is:

1. In the operation of an alternately working gas generator combined with a heat accumulator serving during the run as vaporizer, a recuperator serving during the run for superheating the steam and a waste heat boiler for utilizing the heat of the produced gas during the run, the step which consists in simultaneously passing a part of the waste gases leaving the recuperator into the vaporizing accumulator and another part of the waste gases into the boiler."

2. A gas generating apparatus comprising 'a gas generator, a recuperator, a vaporizer, a

nature.

ALBERT BREISIG.

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