US 1533859 A
Description (OCR text may contain errors)
April 14, 1925.
W. B. HODGE AIR CONDITIONING SYSTEM Filed Dec. 18, 1923 2 Sheets-Sheet 1 alibo'z 11015 April 14, 1 925.
W. B. HODGE AIR CONDITIONING SYSTEM Filed Dec. 18, 1923 2 Sheets-Sheet 2 Patented Apr. 14, 1925.
UNITED STATES 1,533,859 PATENT OFFICE.
WILLIAM B. HO'IDGE, OF CHARLOTTE, NORTH CAROLINA, ASSIGNOR TO PARKS- CRAMER COMPANY, OF FITCHBURG, MASSACHUSETTS, A. CORPORATION 01' MASSACHUSETTS.
Application filed December 18, 1923. Serial No. 681,439.
To aZZ whom it may concern:
Be it known that I, WILLIAM B. HODGE, a citizen of the United States, residing at Charlotte, in the county of Mecklenburg and State of North Carolina, have invented certain new and useful Improvements in Air-Conditioning Systems, of which the following is a specification.
This invention relates to air conditioning apparatus, and particularly to central station systems for heating and humidifyin% air and delivering it to buildings.
uch systems customarily draw their supply of air partly from out of doors, and partly from a return duct leading from the building, and the spray heads used to hu- Inidify the air wash out of the air considerable quantities of dirt and'lint. A considerable portion of the water-sprayed to humidity the air is precipitated either directly or in the ehminators customarily used, and in order toconserve this water and again feed it to the spray heads, it is necessary to remove from it the dirt and lint which it has washed from the air.
This function has heretofore been performed chiefly by screens, which have given serious difiiculty, first because they are difficult to clean without shutting down the plant, and second, because they will pass slender elongated particles, which cause serious trouble in the spray heads.
The present invention involves the use of a granular bed filter such, for example, as a sand or gravel bed filter. This arrangement has two outstanding advantages. First, it is peculiarly effective in removing lint and fine particles from the water, and second, it can readily be cleaned by backwashing, while the air conditioning plant continues in operation.
A preferred embodiment of the invention is illustrated in the accompanying drawin ,in'which:
Fig. 1 is a vertical axial section through the air conditioning duct of a central station system;
Fig. 2 is a sectional plan view thereof on the line 22 of Fig. 1.
Fig. 3 is an enlarged section through a lateral showing the branches;
Fig. 1 is a section on line 4-4 of Fi 3. The duct is usually constructed of s eet metal as indicated at 5. Air enters from when it is desired to heat the air.
out of doors, under the control of adjustable louvres 6, and from the return duct under the control of adjustable louvres 7. These louvres are controlled in any usual manner to regulate the proportions of thereturn air and fresh air.
This air flows to the right, relatively to F ig.-1, and first passes through water spray issuing from the spray heads or nozzles 8, mounted on the vertical pipes 9. These pipes 9 are fed from a header 10, which in turn receives its supply from a centrifugal or other pump 11. The pump 11 is driven by an electric motor 12 or by any other suitable means. After the air has passed through the spray from the nozzles 8, it passes through eliminators 13 of any suitable construction, which remove from the air any excess moisture. After passing through these eliminators, the air flows through heating coils 14, andpasses thence to the fan 15, which discharges it through the duct 16 to the building. V
The heating coils 14 are operated onllly T esupply steam connection is shown at 17 and the condensate drip connection at 18. The
particular form of the heating coils, the
heating medium used, and the manner of contro ing the coils are all subject to variation, as will be readily understood by those skilled in the art.
Any precipitated spray from the nozzles 8, and also the water removed from the air by the eliminators '13, flows directly into a granular filter bed 19, consisting of a bed of gravel, of suitably selected size, contained in a tank 20, mounted in the duct 5 beneath the spray nozzles 8 and the eliminators 13. The water flowing down through the gravel bed is carried away through a drain structure mounted near the bottom of the bed 19, and consisting in the examp-1e illustrated, of a main 21, having a plurality of oppositely extending laterals 22. Each of the laterals 22 is provided with a plurality of arms or branches 23, transversely slotted on their lower sides as clearly indicated at 24. The right-hand end of the main 21 is plugged as shown at 25, and similarly the outer ends of all the laterals 22, and branches 23, are closed. Consequently, the water drawn from the bottom of the filter bed 19 through the main 21,
must enter through the slots 24, and these are so dimensioned as to preclude the entrance of any particles of gravel.
The main 21 opens at 26 into a sump 27, known as the clear-well, and it is controlled by a valve 28, which is operable from a point outside the duct 5, by means of a handwheel 29.
When the valve 28 is open, the water seeping downward through the filter bed 19 flows by way of the main 21 to the clear-well 27 Since a certain amount of sprayed water is taken up by the air-current, it is necessary to provide make-up water, which is admitted to the clear-well 27, from any suitable source, through the pipe 30, controlled by the valve 31.
The ump 11 draws its entire supply of water ii'om the clear-well 27 through the pipe 32. The intake end of the pipe 32 is provided with a fitting 33, into which steam is injected through the pipe 34, the purpose being to heat the water fiowin to the pump 11. The steam supply througi the pipe 34 is controlled by a valve 35, or in any other suitable manner.
A pipe 36 leads to the main 21, and to it leads a water supply connection 37, controlled by a valve 38, and an air supply connection 39, controlled by a valve 40. An overflow 41, .whose inlet is slightly above the top surface of the filter bed 19, serves as the means for carrying off the back-wash water and the dirt, and hence leads to any suitable discharge.
The operation of the louvres 6 and 7, spray nozzles 8, eliminators 13, heating coils 14, and fan 15, are familiar to those skilled in the art. Briefly, they control the admission of the air, its humidification, the removal of excess moisture, the heating of the air, and its delivery to the building.
In the operation of the device a certain amount of moisture is preci itated. It flows upon the filter bed 19, w ich operates to remove the dirt and lint, the latter being retained upon or near the top of the bed while the water percolates through the bed. Clear water thus enters through the slots 24 and flows by way of the laterals 22 and main 21, through valve 28, which is normally open, to clear-well 27. From the well 27, this water, together with a certain amount of make-up water supplied through pipe 30, is drawn through heater 33 by pump 11. The pump 11 discharges it through header 10 to spray nozzles 8.
When it becomes necessary to clean the filter bed 19, the valve 28 is closed by means of the wheel 29, which, as stated, may be operated from a point outside the duct 5. Pump 11 continues in operation, and the clear-well 27 is then fed with water only by the make-up connection 30. Back-washing is then effected in either of two ways. The
first is to admit air alone, under a. moderate pressure, through the valve 40, pipe 36, main 21, laterals 22, and branches 23. This air issuing from the slots 24 over substantially the entire area of the filter bed 19 will produce violent ebullition at the surface of the bed 19. Since the valve 28 is closed, water from the spra heads will rapidly accumulate in the ta of the overflow 41, will carry away the dirt and lint freed by the ebullition of the bed.
The second, the more rapid way, is simultaneously to admit air, by way of the valve 40, and water, under a proximately the same pressure, by way 0 valve 38. This increases the rate of outflow of water through the overflow 41, and produces a definite upward flow of water through the bed 19. Consequently, the cleaning of the filter bed by this method is more rapid and complete. As soon as the bed has been cleaned, the valves 38 and 40 are closed, and the valve 28 is opened.
It will be observed that this apparatus for removing impurities from the water offers marked practical advantages. It is peculiarly effective as a strainer, and 1t may be cleaned while the air conditioning plant continues in operation. Such cleaning is thorough, and is brought about without the use of complicated apparatus.
Some changes in the specific embodiment of the device are obviously possible, and are contemplated. The exact size and nature of the filter bed will vary somewhat with the nature of the plant, and with the character of impurities carried by the air treated. I use the term filter of the granular bed type as a generic term in this connection.
What is claimed is:
1. In an air conditioning plant, the combination of an air duct; means for propelling air therethrough; water Sprayers in said duct; means for collecting water pre cipitated in said duct; a pump connected to draw water from said collecting means and feed it tosaid sprayers; a filter of the granular bed type associated with said collecting means and arranged to filter the collected water on its way to the pump; means for disconnecting saidfilter from said collecting means; auxiliary means for supplying water to said sprayers; means for producin a reverse flow of waterthrough said filter d to back-wash the same; and an over-flow positioned above the normal water level on said bed and serving to carry ofi the back-wash water and water precipitated from said spray heads during the backwashing operation.
2. In an air conditioning plant, the combination of an air duct; means for propelling air therethrough; water sprayers in 88.1
20, and, flowing off by way.
duct; a filter of the granular bed type Ill arranged to receive Water precipitated in said duct; a reservoir fed by water passing said filter; an auxiliary Water supply for said reservoir; a pump connected to draw water from said reservoir and feed it to said sprayers; means for cutting off communication between said filter and reservoir; and connections'for supplying air under pressure through the discharge of the filter to back-wash the latter.
3. In an air conditioning plant, the combination of an air duct; means for propelling air therethrough; water sprayers in said duct; a filter of the granular bed type arranged to receive water precipitated in said duct; a reservoir fed by water passing said filter; an auxiliary water supply for said reservoir; a pump connected to draw water from said reservoir and feed it to said sprayers; means for cutting off communication between said filter and reservoir; and connections for supplying water and air under pressure through the discharge of the filter to back-wash the latter.
4. In an air conditioning plant, the combination of an air duct; means for propelling air therethrough; water sprayers and eliminators in said duct; a granular filter bed beneath said sprayers and eliminators; a reservoir; a branched drain leading from closely spaced inlets submerged in said bed, to said reservoir; a valve controlling said drain; means for delivering water from said reservoir to said sprayers; auxiliary means for supplying water for said sprayers; and connections to said drain arranged to supply fiuid under pressure for back-washing said filter bed.
5. The combination of a water spraying humidifier of the type in which excess Water precipitated from the humidified air is returned to the sprayers and again sprayed; a filter of the granular bedtype interposed in the path of the returning water; connections for back-washing said filter including means for cutting off the return flow from the filter to the sprayers; and an auxiliary water supply for said sprayers serving to compensate for the spray evaporation and to keep the sprays in action during the back-washing'operation.
6. The combination of a water spraying humidifier of the type in which excess water precipitated from the humidified air is returned to the sprayers and again sprayed; a filter of the granular bed type interposed in the path of the returning water; means for cutting 01f the return flow on the discharge side of the filter; means for backwashing the filter by fluid under pressure admitted through the filter discharge; and an independent water supply for said heads.
In testimony whereof I have signed my name to this specification.
WILLIAM B. HODGE.