US3018088A

US3018088A - Room unit for air conditioning

Info

Publication number: US3018088A
Application number: US3642A
Authority: US
Inventors: Allander Claes; Larkfeldt Birger
Original assignee: Svenska Flaktfabriken AB
Current assignee: Svenska Flaktfabriken AB
Priority date: 1959-01-26
Filing date: 1960-01-20
Publication date: 1962-01-23
Anticipated expiration: 1979-01-23
Also published as: FR1246055A; NL120651C; DE1167507B; GB880536A; BE586913A; NL247750A; CH389862A; AT215127B

Description

Jan. 23, 1962 c. ALLANDER ETAL 3, 1

ROOM UNIT FOR AIR CONDITIONING 2 Sheets-Sheet 1 Filed Jan. 20, 1960 vll 7lllllllllllfi vllllfllll INVENTORSI CLAES ALLANDE R BIRGER L'A'RKFELDT WW ATTY8.

Jan. 23, 1962 c. ALLANDER ETAL 3,018,088

ROOM UNIT FOR AIR CONDITIONING Filed Jan. 20, 1960 2 Sheets-Sheet 2 FIGS.

FIG4.

INVENTORSI CLAES ALLANDER BIRGER LARKFELDT' ATTYS.

United States Patent ()fiiice 3,018,988 Patented Jan. 23, 1962 3,018,t388 ROGM UNIT FOR AIR CONDITIONING Class Aliander, Soda-a Angby, and Birger Larkfeldt,

.lonkoping, Sweden, assignors to Aktiebolaget Svenska Fialtttabriken, Naclra, weden Filed .Ian. 20, 196i), er. No. 3,642 (Ilaims priority, application Sweden Jan. 26, 1959 6 Claims. (Cl. 257-137) The present invention relates to a room unit for air conditioning intended to be supplied with primary air, pre-treated in a central plant, which in the room unit is mixed with ejected secondary air from the room. The unit consists of a housing with a substantially rectangular cross section connected to a duct for the supply of the primary air and having means for mixing with the primary air secondary air from the room by the ejection effect. The unit includes heat-exchangers for conditioning the secondary air connected to a pipe line for supplying either heating or cooling medium and is also provided with an inlet for said secondary air and an outlet for mixed primary and secondary air.

The invention relates to units of the above mentioned type which are provided with a central shielded passage connected at its bottom to said duct for the supply of the primary air or to a pressure chamber situated in the lower part of the housing and connected to said duct. At the top the passage is provided with nozzle means constituting the mentioned ejection-mixing means. The heat exchanger is divided into two units, arranged on opposite sides of said central passage and the intake for the secondary air consists of upper and lower inlet openings in the housing located above and below the heat-exchangers respectively. The upper openings are equipped with swingable dampers, arranged in one of its end positions to close the passage of the secondary air through the heatexchangers and in its other end position to open said passage and instead completely close the upper inlet passage.

Room units of the above mentioned type are nowadays be supplied with either heating or cooling medium to make it possible to heat or cool the air according to the actual need with one and the same heat-exchanger. The size of the heat-exchange surface of the heat-exchanger is determined by the lower temperature difference used when cooling the air. This heat-exchange surface will, however, be unnecessarily large for heating the air with accompanying difliculties for an adjustment as accurate as desired for an individual final adjustment of the kind for which room units of the above mentioned construction are intended.

The new and improved room unit according to the invention is characterized in that the secondary air proportioning dampers are arranged to be adjusted simultaneously with and by the same mechanism which is used for operating the valve regulating the flow of the heating or cooling medium in the heat-exchanger, and in such a way that during adjustment of the valve from closed to open position first only one of the two secondary air proportioning dampers is turned from its end-position closing the passage of the secondary air through the heat-exchanger to its other end position, while the turning of the other damper is started just after the first damper has reached its last mentioned end position.

usually made in such a way that the heat-exchanger can Owing to the fact that the heat-exchanger in accordance with the invention is divided into two halves, arranged on both sides of the ejecting means and because of said damper arrangement it is possible to put half of the heat-exchanger out of action when the heat-exchanger is supplied with heating medium. By shutting down half of the heat exchanger, an unnecessary over-heating of the secondary air can be avoided. By an adjustment of the dampers to suitable intermediate positions furthermore the proportion between treated and non-treated secondary air as well as the proportion between primary air and secondary air can be varied, whereby the possibility to adjust the air temperature is further improved both when it comes to heating or cooling. The dampers can also be used for the adjustment of the air temperature even in those cases when the primary air is shut OE and the secondary air is caused to pass the heat exchanger halves only by self-draft.

The central passage may preferably be provided with a separately operated shut-oft damper in order to make possible to shut oil the supply of the primary air. To accomplish the simultaneous adjustment of the two secondary air proportioning dampers and the valve, the valve according to an appropriate embodiment is made with an extended spindle, arranged half-way between the pivotal axes of the dampers, and connected to an adjustment knob on top of the room unit. For the adjustment of the two dampers, a cylindrical drum provided with two tracks is mounted on said spindle. The dampers are provided With crank levers mounted on their pivotal shafts, which directly or via a link-mechanism engage said tracks. The tracks are designed so that the dampers are adjusted in the above mentioned way. For strengthening of the ejecting eifect from the primary air there is, according to an additional feature of the illustrated embodiment, a venturi channel between the heat-exchanger and the outlet situated on top of the room unit, which channel at its lower end communicates with the outlet side of the heat-exchangers as well as with the mentioned upper inlets of the housing. In the same way the upper part of the central passage, between the heat-exchangers which is connected with the ejecting means, can be made as a venturi passage.

The invention will now be closer described with reference to the accompanying drawing showing an exemplifying embodiment of a unit according to the invention.

FIG. 1 shows a vertical cross section through the unit taken on the line 1-1 of FIG. 3.

FIG. 2 also shows a vertical cross section through the unit taken on the line 2-2 of FIG. 3 close to the end of the unit.

FIG. 3 is a front elevation of the conditioning unit with the casing broken away.

FIG. 4 is a section of the cam drum and housing taken on the line 44 of FIG. 2.

FIG. 5 is a perspective view of the cam drum removed from the unit.

In the drawing, the illustrated embodiment of the room unit comprises a housing 1 having a duct 2 for the supply of primary air and a nozzle 3 connected to the duct by means of a central passage or pressure chamber 8 for the primary air, which nozzle serves as a means for the ejection and mixing of secondary air from the room. Two heat-exchanger halves or units 4a and 4b are arranged on opposite sides of the central passage 8 and are designed for either heating or cooling the secondary air from the room. The secondary air is taken into the unit either through two lower inlet openings 5a and 51) or through upper inlet openings 6a and 6b. An outlet 7 on the top of the unit exhausts the mixed primary and secondary air, which passes through a venturi channel 33 arranged between the heat-exchanger units 4a and 4b and the outlet 7. Swingable dampers 9a and 9b are pivoted on shafts 10a and ltlb respectively. Each damper is arranged to shut oil? in one of its end positions A the passage 41a or 41b for the secondary air through the associated heated-exchanger half, and in its other end position B to completely open the passage 41a or 41b and instead of this, completely shut ofl the passage 42a or 42b between the channel 33 and the upper inlets 6a and 6b for the secondary air.

In accordance with the invention, a common means is provided for adjusting the dampers 9a and 9b, and a valve 12 which regulates the heating and cooling heatexchange medium in the heat-exchanger halves 4a and 4b. The valve 12 is connected at one side to an outer supply line 13 and at the other side by means of a pipebend 14 to one of the heat-exchanger units 4b, which by means of a connection 14a (FIG. 3) is joined to the other heat-exchanger unit 4a, the outlet of which is indicated at 15. The valve 12 has an extended spindle 16 which is disposed half-way between the turning shafts Mia and 10b of the proportioning dampers. The spindle is connected to an adjusting knob 11. The spindle 16 and knob 11 serve as the common adjustment means because of an adjusting means 17 mounted on the spindle for adjusting the dampers 9a and 9b in accordance with the invention. The adjusting means 17 consists of a cylindrical drum 18 enclosed in a casing 19. The drum is provided with two tracks 29 and 21 forming cam surfaces for two follower rollers 22a and 22b which support two rods 23a and 23b, the lower ends of which form a yoke enclosing rolls 25a and 25b respectively. The rolls 25a and 2511 are mounted on the damper shafts 10a and 1% by means of crank levers 26a and 26b. The rods 23a and 23b are biased downwardly by springs 24a and 24b to press the follower rollers 22a and 22b against their respective tracks. The

tracks

20 and 21 in the drum 18 are so constructed that during adjustment of the valve 12 from closed to open position, at first only one of the dampers-An the illustrated embodiment 9b-is turned from its end position A for closing the passage 41a to its other end position for closing the passage 42a. When the damper 9b reaches the limit position B the other damper, in the illustrated embodiment 9a, is actuated from its position A to its position B. In order to prevent direct communication between the upper and lower inlets for the secondary air, packings 1a and 1b are inserted between the housing 1 and the respective heat-exchanger units 4a and 4b.

Through an adjustment of the dampers to suitable intermediate positions, the proportion between treated and non-treated secondary air as well as the proportion between primary air and secondary air can, as mentioned above, be varied. The amount of primary air is intended to be kept constant at a pre-set value. In order to facilitate the keeping of said value constant there isin the illustrated apparatusa volume flow governor 27 mounted in the passage 8 immediately above the outlet opening of the primary air duct 2. The value of the primary air volume can be varied by changing the working position of the volume flow governor, which change is made by means of a mechanism 28. To completely shut off the supply of primary air when necessary the unit is provided with a damper 29 turnable around a shaft 30, and arranged in the passage 8 just above said volume flow governor 27. The damper 29 is intended to be operated Separately, i.e. independently of the above mentioned dampers 9a, 9b. In the illustrated apparatus the adjustment is made by means of a disc 31 attached to the shaft 30, an operating rod 32, attached to a bridge 33 and two adjustment knobs 34a, 34b. To obtain an instantaneous adjustment between the end positions for the damper 29, the disc 31 is actuated by a spring 36, coiled around a pivoted rod 35 which is tiltable between two over-center positions. To guaratee an even distribution of the primary air through the ejecting nozzle without disturbing sounds and with the least possible pressure drop, the upper part of the central passage located between the heat-exchanger units and connected to the ejecting means is made as a venturi channel 37. For the strengthening of the ejecting eifect from the pnimary air, the channel 38 is a venturi passage.

The unit housing shown in the drawing can without departing from the idea of the invention be omitted and replaced by furring built-in at the erection place, which furring possibly can be common for several room units. The embodiment of the adjusting means 17 shown in the drawing can without departing from the idea of the invention be varied by using other guiding and transferring elements. In order to prevent both the heatexchanger halves from being opened when heating medium is supplied to the heat-exchanger halves, ie to limit the operation of the damper adjustment mechanism in accordance with what is mentioned above, so that only one of the dampers is actuated, this mechanism may suitably be provided with a stop element which limits the turning operation carried out by means of the knob 11. This stop element can suitably be arranged to be automatically actuated by a temperature sensitive instrument mounted on the supply pipe line for the heating and cooling medium respectively. Said element can also be made to simultaneously carry out an automatic reverse of the indication symbols, intended to indicate the proper turning direction for the adjustment knob 11 for the respective kind of medium to change the room climate towards warmer.

What we claim is:

I. In a room unit for air conditioning having a primary air inlet duct, a central passage connected at its lower end to said inlet duct and terminating at its upper end in an ejection nozzle, two heat-exchanger units mounted on opposite sides of said central passage, secondary air inlets to introduce secondary air into the room unit for mixing with said primary air by ejection, said secondary air inlets including an upper opening operable to bypass the air in a passage around said exchanger units to mix with said primary air at said ejection nozzle and a lower opening operable to direct the air in a passage through Said heat-exchanger units to mix with said primary air at said ejection nozzle, and a damper for each unit operable to proportion the flow of secondary air through said bypass and heat-exchanger passages, the damper in its first limit position opening said bypass passage and closing said heat-exchanger passage and in its second limit position closing said bypass passage and opening said heatexchanger passage, a conduit supplying heat-exchange medium to said heat-exchanger units and a valve regulating the flow of heat-exchange medium through said units, the improvement comprising a single operating mechanism for said dampers and said valve operable during operation of said valve from closed to open position to first displace one of said dampers from its first to its second position while retaining the other damper in its first position and thereafter during said operation of said valve to displace the other damper from its first to its second position while retaining said one damper in its second position.

2. A room unit according to claim 1 including a separately-operated shut ofr damper in said central passage to shut off the flow of primary air therethrough.

3. A room unit according to claim 1 wherein said single operating mechanism includes a turning shaft for each damper, a spindle for said regulating valve projecting upwardly between said shafts and terminating in an adjusting knob, said spindle mounting adjusting means cooperable with dampers to efiect said sequential displacement of said dampers.

4. A room unit according to claim 3 including operating lever means on said dampers to pivotally displace the latter on their turning shafts, said adjusting means comprising a generally cylindrical drum having two tracks forming cam surfaces engaging said lever means to effect said sequential displacement of said dampers upon rotation of said spindle to operate said valve.

5. A room unit according to claim 1 including a venturi flow passage connected at its lower end to said heat exchanger passages, said by-pass passages and said ejection nozzle, and operable to exhaust air into the room 15 2,567,758

References Cited in the file of this patent UNITED STATES PATENTS 1,753,157 Otis Apr. 1, 1930 1,849,061 Anderson Mar, 15, 1932 2,144,466 Stikeleather Jan. 17, 1939 2,238,689 Locke Apr. 15, 1941 2,287,267 Palmer Iune 23, 1942 2,501,795 Stephens Mar. 28, 1950 Ashley Sept. 11, 1951