USRE19276E - Method of and apparatus fob regu - Google Patents

Description

Aug. 14, 1934. N CH Re. 19,276

METHOD OF AND APPARA'I US FOR REGULATING 0R GOVERNING PHYSICAL CO NDITIONS Original Filed Sept. 21, 1927 T l f v,i//// //////1.

Guido ZM z/' I yij Reissued Aug. 14, 1934 I Q UNITED STATES I c 19,276 -METHOD or AND APPARATUS FOR BEGU- LATING on oovnmwmo PHYSICAL coN- DITION S Guido Wiinsch, Steglitz, near Berlin, Germany,

assignor' to Askania-Werke Akt. Ges. vorm.

, Centralwerkstatt Dessau und Carl Bambe'rg-= Friedenau, Berlin-Friedenau, Germany Original No. 1,920,827, dated August 1, 1933,

Serial No. 221,122, September 21, 1927.

Application for reissue February 28, 1934, Serial No. 713,425. In Germany September 21, 1926 15 Claims. (Cl. 236-26) This invention relates to methods of and apparatus for regulating or governing physical conditions. Such 'methods and apparatus are known, but-so far as I am aware all those heretofore used suifer from the disadvantage that an appreciable time interval elapses between the instant at which the regulating or governing action is initiated and the time when said action becomes eifective. During this time interval the regulating or governing action may be subjected to influences that impair its accuracy and efiectiveness, such impairment being greater or less according to the length of said time interval. Also the corrective action .may under certain conditions reach a point in excess of that required, in

other words overshoot the mark, before it is arrested, so that further corrective action in the opposite direction becomes necessary. This puts an unnecessary burden upon the regulating or governing means employed and results in an unnecessary waste of the supply of energy Productive of the physical condition to be regulated. Thus in the case of the regulation of a well-known physical condition, for instance temperature, the temperature of an oven for example, when the desired temperature is exceeded, the source of heat, the supply of gas for instance, is reduced, while onthe other hand when the temperature falls below that required, said supply is increased. The temperature of an oven, however, changes very slowly, so that when, due to a fallbelow or a rise above the desired temperature, the supply of gas is increased or respectively, an appreciable time interval will necessarily elapse before the desired temperature is restored, the length of said time interval varying with the capacity of the oven. When the temperature falls below the temperature desired and the supply of gas is accordingly increased as above stated, the time interval required to restore the temperature tothe desired degree in many instances is such that the amount of gas supplied for this purpose far exceeds that required normally to maintain the correct'temperature, so' that the temperature will I rise above that desired and the regulator is compelledto operate again to reduce the supply of gas. This oscillating operation before the right temperature in the oven is. obtained 'or restored may. continue some time which makes for unnecessary waste of gas and imposes an extra tax on the regulating or governing apparatus.

One of the objects of the present invention is to provide a method of and apparatus for regulating or governing physical conditions, which shall be reliable and accurate in operation and which said nozzle.

diaphragm g of a diaphragm chamberg, this shall function without waste, eliminating the objectionable features above set forth. a

Other objects of the invention will appear fro the following description.

The invention and its aims and objects will be no readily understood from the following descrip-' tion of the best mode and manner at present known to me for putting my invention into execution, and of a diagrammatic representation in the accompanying drawing of one illustrative apparatus for that purpose, the true scope of the invention being pointed out in the appended claims. The apparatusshown in the drawing-is for the regulation or governing of temperature, but it is to be understood that my invention is not to be 7 considered as'limited to the regulation or govem ing of that particular physical condition, but that it is equally applicable to the governing or regulation of pressure and other physical conditions. Referring to the drawing, a is a boiler or an oven in which it is desired to maintain a certain definite temperature by means of the burner 0 fed with fuel through a pipe b. A fluid thermostat (1 comprising the heat sensitive means is provided in the boiler and sets up a pressure in a diaphragm chamber or bellows which'is connected with a pivoted jet nozzle 1. A continuous stream of fluid under pressure, preferably air, is caused to flow through thisjet nozzle from a suitable source of supply, not shown; the air from said nozzle entering a tube It to a greater or less extent, depending upon the position of The air entering the tube It passes to a chamber 1-4:: and exerts pressure on the pressure continuing to increase until the force on the diaphragm equalizes the force exerted by the thermostat d or bellows e. If the temperature and therewith the fluid pressure inv e is constant, then the entire arrangement will remain in equilibrium and the same pressure will prevail in g, k and i, said pressure being indi cated by the gauge 1'. If, however, the temperature rises, then the pressure in e also rises and air under pressure flows through the resist -10o ance chambers '11-lc.in the direction iF-Jc. The quantity of air flowing from 1'. to k and, therefore, the pressure difierential between i and k can be regulated by a reservoir chamber m connected as shown to the chamber k. The more rapid the temperature changes in the boiler or oven, the quicker the pressure will change in e, and more air will be forced. into g and m. By means of a device, for example a capillary resistance n of conventional construction inserted between i and k, a pressure difference will be caused to exist between i and k and this pressure difierence will vary in proportion to the flow of air through the capillary tubes and can be read from thefpressure difierence meter q. This pressure difierence is proportional to the speed with which the pressure changes in g (and m) and therefore to the speed or rate of change of the temperature in the boiler or oven a.

In the illustrative embodiment of the invention the rise in pressure indicated at 'r is proportional to the rise in temperature in the boiler or oven, and the diiference in pressure indicated at q is proportional to the rate of change of the temperature in said boiler or oven.

In the illustrative embodiment of the invention the amount of heating gas delivered by the pipe b is governed by a throttle slide 2 operated by a piston y operating in a cylinder y. The

piston 11 is operated by a second jet nozzle '0' to which air under pressure is continuously supplied from a suitable source not shown, said jet nozzle being pivoted similarly to the jet nozzle ,f' and cooperating with tubes 2: and x which communicate with opposite ends of the cylinder -11 respectively. According as the diaphragm u swings said jet nozzlev in the one orthe' other direction about its pivot compressed air will flow from said nozzle to a greater or less degree into the one or the other of the two tubes 3: and

supply compressed air to the tube 3: thus raising the piston 1 and opening the throttle slide z to increase the flow of gas to the burner c.

Ii for any reason the temperature in the oven begins to rise rapidly, the jet nozzle 1 will be 'moved rapidly resulting in a vigorous flow between i and k. In the chamber i the pressure increases rapidly sometime before the pressure in g and It becomes noticeably greater. The

regulating diaphragm u will thus operate to throttle the supply of gas considerably until the pressure in i regains its original value. On the other hand it for any reason the temperature begins to fall, the jet tube 1 will be moved in the opposite direction resulting in a diminished flow between i and k. In the chamber 1' the pressure will decrease rapidly sometime before the pressure in a and k becomes noticeably less. The regulating diaphragm u will thus operate to increase the supply of gas considerably until the pressure in i regains its original value.

' It will thus be seen that a force proportional to the change in the physical condition to be regulated and a second force proportional to the rate of change in said physical condition are used' to regulate or govern said physical condition, the sum or resultant of said two forces exerting a regulating or governing action for this purpose upon the supply of energy productive of said physical condition. So far as I am aware this is novel and results in a very sensitive, stable and damped regulation since the regulating or governing means isinfiuenced not only by the magnitude of the condition to be regulated but I also by the rate of Increase in pressure causes the change of said physical condition. l

It will be understood that the resistance 11. must be kept within such bounds that it will not hinder the flow of pressure fluid to and from the chamber 9 that'is necessary for maintaining the balanced condition of the nozzle f.

I am aware that the invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and I therefore desire the present embodiment to be considered in all respects as illustrative and not restrictive, reference being had to the appended claims rather .than to the foregoing description to indicate the scope of the invention.

I claim:

1. In apparatus for regulating or governing temperature in an enclosed space, in combination, means to heat the contents of said space; a pressure fluid operated regulator for said heating means; means to supply pressure fluid to operate. said regulator; fluid pressure responsive.

means connected to control the application of the pressurefluidwhich operates the regulator; a source of controlling pressure fluid communicating with said-pressure responsive means; pressure operated governing means influenced by the temperature in said space and connected to means results in said first mentioned fluid pressure responsive means controlling the operation of said regulating means in response to a fluid pressure which is the resultant of a pressure proportional to the change in temperature in said space and a pressure proportional to the rate of change of the temperature. I

2. In apparatus for regulating or governing temperature in an enclosed space, in combination, means to heat the contents of'said space; a pressure fluid operated regulator for said heating means; meansto supply pressure fluid to operate said regulator; pressure responsive means controlling the application of pressure fluid; a source of controlling pressure fluid communicating with said pressure responsive means; pressure operated governing means influenced bythe temperatrue in said space and connected to govern the application of the controlling pressure fluid, and

a second pressure fluid responsive means-also the opposed action of the governing means and the second pressure fluid responsive means on the source of controlling pressure fluid imposes a pressure on the first mentioned pressure fluid responsive means which is the resultant of a pressure proportional to-the change in temperature of the space to be heated and a pressure proportional to the rate of said change.

3. In regulating or governing apparatus of the character described,.in combination, a pressure fluid operated regulator for a condition to be regulated; means to supply pressure fluid to said regulator; pressure fluid responsive means connected to control the operation of said regulator; a source of controlling pressure fluid communicating with said pressure responsive means; force exerting means responsive to changes in magnitude of the condition to be regulated and connected to control the application of the .pressure fluid from said source; a second pressure fluid responsive means also communicating with said source of pressure fluid and connected to oppose the action of said force exerting means on said source of pressure fluid; and flow resist-' ing means between said source of pressure fluid tion and arrangement being such that actuating or adjusting movement of said source of pressure fluid imparted by said opposed force exerting means and said second pressure fluid re- 'sponsive means results in said first mentioned fluid pressure responsive means controlling thegbperation of said regulator in response to a resultant pressure influenced by a pressure proportional to the change in the physical condition to be regulated and influenced by a second pressure proportional to the rate of change of said physical condition. p

4. Temperature regulating or governing apparatus comprising, in combination; a source of heat for the appliance in which the temperature is to be regulated or governed; a throttling member in the source of heat supply; a fluid pressure operated servo-motor connected to operate the throttling member; fluid pressure responsive means connected to control the operation ofthe servo-motor; and means for supplying fluid under pressure to said fluid pressure responsive means at a pressure influenced by both the temperature to be governed and the rate of change of said temperature, including a source of fluid pres-- sure, a chamber communicating with the source of pressure and with the pressure responsive means, a second chamber communicating with said first named chamber; flow resisting means quantity of pressure fluid flowingtherethrough; and controlling means connected to vary the pressure fluid supply to said first named chamber comprising a measuring system exerting a force proportional to the instant temperature to be governed and a measuring device communicating with the second chamber exerting an opposing force proportional to the pressure in said second named chamber.

5. Temperature regulating or governing apparatus comprising, in combination, a source of heat for the appliance in which the temperature is to be regulated'or governed; a throttling member .in the source of heat supply; a fluid pressure operated servo-motor connected to operate said throttling member; fluid pressure responsive means connected to control the operation of the servo-motor; means for supplying fluid under pressure to said fluid pressure responsive means at a pressure influenced by both the instant temperature to be governed and the rate oi 'change of said temperature, including a source of fluid pressure, a chamber communicating with the 4 source of pressure and with the pressure re-- tional to the quantity of pressure fluid flowing and said second responsive means, the construcbetween said chambers to provide a diiference in pressure in said chamber proportional to the a eating with said first named chamber, flow resisting means between said chambers to provide a diflerence in pressure in said chamber propor-' therethrough; and controlling means connected to vary the pressure fluid supply to saidflrst named chamber comprising a measuring system exerting a force proportional to the instant temperature to be governed and a measuring device communicating with the second chamber exerting an opposing force proportional to the pressure in said second named chamber, and an auxiliary pressure chamber communicating with said second chamber.

6. In regulating or governing apparatusof the character described, in combination,a fluid pressure operated regulator for a condition to be regulated; a source of fluid pressure to actuate said regulator; fluid pressure responsive means connected to control the application of the fluid pressure which actuates the regulator; a second source of fluid pressure connected to supply pressure to said fluid pressure responsive means; means responsive to changes in the condition to be regulated connected to control the application of pressure from said second source of fluid pressure; a second pressure responsive means communicating with said second source of pressure and connected to oppose the actionof said condition responsive means on said second source of fluid pressure; and means to impede the passage of fluid pressurefrom said second source of fluid pressure to said second fluid pressure responsive means. I

7. In regulating or governing apparatus of the character described, in combination, a regulator for a condition to be regulated; operating means therefor; fluid pressure operated means responsive to variations in-fluid pressure to control said operating means; fluid pressure supplying means for said fluid pressure operated means; actuating means responsive to changes in the condition to be. regulatedv connected to actuate said fluid pressure supplying means and vary the amount of pressure fluid supplied thereby to said fluid pressure operated means; opposing means, responsive to pressure fluidsupplied by said pressure fluid supplying means, to influence said fluid pressure supplying means in opposition to said actuating means; and means to impede the passage of fluid pressure to said opposing means.

8. In apparatus of the character described, in combination, a regulator for a condition to be'130 regulated; operating means connected to the regulator; a source 01' energy connected to control said operating means; governing means connected to control the application of the energy including a device responsive to changes in the condition to be regulated and opposing means controlled by the source of energy and acting upon the source of energy "inopposition to the action of thegoveming means; and means to render the action of the opposing means at flrst I unequal to the action of the governing means but to permit the action of said opposing means gradually to equal the action or said governing m eans.

9. In apparatus for regulating temperature in a space, in combination, heat supplying means; a regulator therefor; operating means for the regulator; a source of enei-gy connected to control the, operating means; governing means infiuenced by changes in the temperature in said space and connected to govem the application or 150 said source of energy; opposing means controlled by the applied energy and acting upon the source of energy .inopposition to the action thereon of 7 said govemingmeans; and means to render the action of the. opposing means at first unequal to the action of the governing means but to permit the actionof said opposing means graduallyto ,equal the action of said governing means.

pressure. inthe governing chamber as the temperature in the heated space changes; and applying themodified pressure to control the supply of heat to said space.

11. That method of regulating or governing temperature in a heated space which comprises directing a jet of fluid under substantially constant pressure into a governing chamber; controlling the jet to vary the quantity of fluid delivered to the chamber in response to changes in temperature in the-heated space; modifying the fluid pressure in the governing chamber by resistance to flow. of the fluid as the temperature in the heated space changes; and applying the modified pressure in the governing chamber to control the supply of fuel which heats said space.

12. Apparatus for maintaining the temperav ture of a body comprising, in combination, means to control the application of heat to said body;

means to create a governing force proportional at all tiines to the algebraic sum of the temperature change and rate of changein the body; and means operable in response to changes in said force to actuate the control means.

13.'Appara tus for maintaining temperature, pressure or other controllable-condition substantially constant comprising, in combination, means to control said condition; means to create a governing force proportional at all 1 times to the algebraic sum of the condition change and rate or condition change; and means operable in re-- sponse to changes in said force to actuate said control means.

14. That method of maintaining a controllable condition substantially constantwhich is characterized by measuring said condition; creating a governing force controlled by the, measurement and variations of said condition which is proportional at all times to the algebraic sum of the change-and the rate of change of the condition; and applying said governing force to control the condition. a

15. That method of maintaining the temperature or pressure of a fluid substantially constant, which is characterized by creating a governing force which is proportional at all times to the algebraic sum of the condition change and the rate of change; and applying said force to control the condition. I

sumo Williams.

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