CRANKCASE CHAMBER

Abstract: Crankcase chamber for oil levelling of compressors and or compression machines for fluids (vapor or gas) connected in parallel in the same circuit, characterized by the creation of a third chamber, called "Crankcase Chamber"; to be used at the Industrial Engineering area. This "Crankcase Chamber" allows the perfect oil level equalization in two or more compressors connected in parallel in the same circuit, specially allowing any one of them to work in partial charge (0% to 100%) and even to have the gravity force preponderancy on the lubricating oil surface. The "Crankcase Chamber" (8) branches off the "Suction Chamber" which is divided into two parts by means of a "dividing cover" (7) resulting in a "Suction Chamber" (2) properly said, and a "Crankcase Chamber" (8), object of this invention. The "Crankcase Chamber" (8) of each compressor must be equalized with the suction pressure. The crankcases are connected between them by means of an "oil Equalizator" (3) and also by means of an available suction pressure intake.

Description: CRANCKCASE CHAMBER The "CRANCKCASE CHAMBER" has the purpose of levelling the oil of compressors and/or compression machines for fluids (vapor or gas) in paralell connection,in the same circuit. It relates to one only invention which is used at the Industrial Engineering area, for levelling the cranckcase oil, when two or more compression machines for gas or vapor are connected in paralell, in the same circuit. The use of this technique is specially destinated for ar conditionning, refrigeration, compressed air and simple processes for mechanical compression of vapor and gas, in general. The compressors, are presented as piston ( reciprocal ) , centrifugal, blade, screw type machines of volumetric displacement, which purpose is the value reduction of the specific volume of a fluid at the physical state of- vapor or gas. The conventional compressor has two pressure chambers: High Pressure or Discharge ( 1 ) and Low Pressure or of Suction ( 2 ) . Figure 1. Into the cranckcase, the suction pressure of its own compressor freely prevails. Figure 1. According to the present technique, there are used two pressure equalization connections for levelling the cranckcase oil in these compression units, when connected in paralell in the same circuit. The connection whose axis passes by the oil level line is called OIL EQUALIZATION (3). The connection over the oil level line is called GAS EQUALIZATION (4).Figure 2. This technique recomends the use of identical compression units, i.e., with the same volumetric displacement , same rotation with suction and discharge intakes, with equal pressure losses. The difficulty to reach the said recommendation ' in practice,is based in the obtain eήt of identical volumetric efficiency, due to the fact of: 1 - having unequal mechanical wear in different machines, propitiated by different operating times; 2 - the difficult for obtaining the same rotation for all the compressors, due to ' the little difference of velocity at the electrical motors or by different friction forces of the movement transmission belts. - In view of these differences, a machine will have one pressure lower than the other, therefore ocurring vapor or gas flow through. the equalization- pipes from the machine of highest pressure to the one of lower pressure. In the compression units, the oil return can be processed • by means of an OIL SEPARATOR (5) placed in the collective or individual discharge of the compressors; also by means of the SUCTION MANIFOLD (6) in systems whose fluids admit the lubricating oil miscibility. Figure 2. Considering these assumptions, the oil flow will prefer the return to the compressor of lower suction pressure , following the internal ' flow of the gas by the oil equalizator (3) Figure 2. This tendency been mantained, during a relatively long operating time, the oil level considerably increases in the compressor of lowest pressure and, therefore, there is a drowdown of the oil level of the other compressors, isking the machine, overflowed of "Liquid hammers" , while the others risk because of the lack lubrication , due' to the obseπce of oil. In case of machines with individual control of capacity i.e., which operate at partial charge, the above solution ; recomended by the present technique is even more critical, considering the big pressure difference created • by the unequal volumetric displacements. The same ocurrs to the paralell compression units of different models. In the two last cases,the present technique recomends the usage of individual oil level controls for each cranckcase, avoiding the oil (3) and gas (4) equalization, showed in figure 2. Present state of the described technique is proved by the following bibliography: 1 - ASHARE HANDBOOK - 1984 SYSTEMS, pg. 24:16 American Society of Heating Refrigerating And Air Conditioning Engineers, Inc; Atlanta, U.S.A. , 1984; 2 - CARRIER, Handbook of Air Conditioning Systems Desing pg. 3-65; Mc. Graw - Hill, Inc; 1960: 3 - COSTA-ENNIO CRUZ DA - Refrigeracao - pg. 162;Editora Edgard Blucher Ltda; Sao PaulojBrazil, 1982. 4 - D0SSAT-.R0Y - Principios de Refrigeraciόn; pg. 661 ; Compania Editorial Continental S.A.; Spain, 1963. 5 - TRANE - Air Conditioning Manual ; pg. 176; THE TRANE COMPANY; LA CROSSE. incosin, 1979. DESCRIPTION OF THE INVENTION Description of the invention - The invention has the purpose of the equalizating the oil levelling, on a reliable and and definitive form, with the creation of a special third pressure chamber, called by the author "Cranckcase Cham ' ber". On figure 3 we can see the separation (7) between the cranckcase (8) and suction (2) chambers. This third chamber branches off the " Suction Chamber" which is divided in two parts by means of a "dividing cover" (7) forming the "suction chamber" (2), properly said, and the "Cranckcase Chamber" (.8), object of the invention (Claim one) . The "dividing cover" (7) tends to avoid the " Cranckcase Chamber" (8) from suffering the influence of the fluid flow which enters the suction chamber ( 2 ) leaving by the discharge chamber (1). The "Cranckcase Chamber" (8) has the special purpose of storing the lubricating oil, so it must . have volumetric capacity bigger than the oil volume , it contains, allowing the free oscilation of the same in its level. The "Cranckcase Chamber" ( 8 ) operates with suction pressure - ( low ) -. In order to have practically the same suction pressure at the "Cranckcase Chamber" (8) the same is connected, by means of a " Capillary Tube of Gas Equalization " (9) in the same point of the Suction General Manifold" (10) Figure 3. It is important that the pressure intake of the suction manifold (6) will be always made at the same point ( 10), Figure 3, and carried to all the compressors by means of a capillary tube (9) . The oil equalization tube (3), in this case, will allow that pressure at the "Cranckcase Chambers" (8) will be equalizated and, therefore, the gravity forces will freely operates, considering that the vapor or ' gas .flow at cranckcases turns minimum, only when eventual escapes would ocurr. Therefore, even any compressor operates from 0% to 100% of its capacity, there will not be allowed a considerable flow of vapor or gas between the " "cranckcase chambers" (8) by de oil equalization tube (3) Figure 4 - The cranckcase pressure shall be equalizated with the suction pressure by means of a capillary tube (9) , caring to interrupt it by the little calibrating hole (11). According to this, the capillary tube (9) is connected in the suction intake of the compressor (12). Different compressors,operating with different volumetric displacements create different pressures at the suction chamber intake (12). Consequently, this pressure difference causes the vapor or gas displacement -through the oil equalizator (3). The calibrating hole (11) is used for damping or reducing the flow between the " Cranckcase Chambers " (8) through the oil equalizator (3). Figure 5 - This solution is similar to the one of figure 4, but because of constructive conveniences it can be adopted a calibrating hole (13) internally set up in the " dividing cover " " (7), equalizating ' the "Suction Chamber" (2) pressure with the one of the "Cranckcase Chamber" (8). The only EXTERNAL connection among the compressors is,now, the oil equalization (3) Figure 5. For the three variations, the gas flow between the "Cranckcase Chambers" (8) of the compressorsis very little so as the gravity forces operate freely on the oil surface. The "Cranckcase Chamber"(8) operates independently from the "Suction Chamber" (2). Due to the fact, it turns interesting the setting up of the "OIL SEPARATOR" ( 5 ) of conventional characteristics. The author considers important, in the three cases, that capillary tube for oil return (14), (which connects the oil separator to the cranckcases) will be equipped with a calibrating hole (15) in order to avoid bigger turbulences in the Cranckcases Chambers" (8). For ' executing this method ' , the technician must create a third chamber, i.e. , the " Cranckcase Chamber " ( 8 ) independent from the suction chambers (2) and discharge chamber ( 1 ) . Figure 3. The technician will construct a- "dividing cover " (7) figure 3, or a wall casted on the same body, which will be placed in the suction chamber (2), for separate physically the Suction Chambers (2) and the "Cranckcase Chamber" (8) figure 3. The "Cranckcase Chamber" (8) has the purpose of storing the lubricating oil, so it must have volumetric capacity bigger than the volume of the oil it contains , allowing that it can freely oscilate in its level. In the three variations, once constructed the " dividing cover " (7), the technician shall set up the oil equalization tube (3) For this purpose, the cranckcases are connected between then, by means of an horizontal tube , with the axis passing by the desired oil level plane, remaining 50% of the section submersed into the oil, and 50% free - figure 3. In the variation N2 1, figure 3, the capillary tube (9)is connected to the same point (10) in the "Cranckcase Chamber" (8) over the oil level, and on the suction manifold (6). In the variation Ns 2, figure 4, the capillary tube is individual for each compressor; it is connected in the "Cranckcase Chamber" (8) over the oil level , and in the suction intake of its compressor (12).The capillary tube shall be interrupted by a little calibrating hole. (11). In the variation N2 3, figure 5, the method is similar to the one of the variation 2, figure 4; only the calibrating hole (13) is internally set up in the "dividing cover" (7), equalizating the "suction chamber" (2) pressure with the one of the "Cranckcase Chamber" (8). For better understanding and reading of figures 3,4 and 5 above referred in the Descrition Report, we will specify the parts identification as follows: Figure 1 : 1 - ' Discharge Chamber 2 - Suction Chamber 3 - Suction line 4 - Discharge line Figure 2 : 1 - Discharge chamber 2 - Suction chamber 3 - Oil equalization tube 4 * - Gas equalization tube 5 - Oil separator 6 - Suction manifold 14 - Capillary tube for oil return 15 - Calibrating hole for oil return 16 - Suction general line 17 - Discharge manifold 18 - Discharge general line 19 - Oil level plane gure : 1 - Discharge chamber 2 - Suction chamber 3 - Oil equalization tube 4 - Gas equalization tube 5 - Oil separator 6 - Suction manifold 7 - Divising cover of the Cranckcase and Suction Chambers 8 - Cranckcase chamber 9 - Capillary tube for gas equalization 10 - Point of the suction general manifold 14 - Capillary tube for oil return 15 - Calibrating hole for oil return 16 - Suction general line 17 - Discharge manifold 18 - Discharge general line ' 19 - Oil level plane Figure 4 : 1 - Discharge chamber 2 - Suct-ion chamber 3 - Oil equalization tube 5 - Oil separator 6 - Suction manifold 7 - Divising cover of cranckcase and suction chambers 8 - Cranckcase chamber 9 - Capillary tube for gas equalization 11 - External calibrating hole 12 - Suction intake of the compressor 14 - Capillary tube for oil return 15 - Calibrating hole for oil return 16 - Suction general line " 17 - Discharge manifold 18 - Discharge general line 19 - Oil level plane Figure 5 : 1 - Discharge chamber 2 - Suction chamber 3 - Oil equalization tube 5 - Oil separator 6 - Suction manifold 7 - Dividing cover of the cranckcase and suction chambers 8 - Cranckcase chamber 13 - Internal calibrating hole 14 - Capillary tube for oil return ι5 - Calibrating hole for oil return • 16 - Suction general line 17 - Discharge manifold 18 - Discharge general line 19 - Oil level plane

Claims: CLAIMS 1 - "CRANCKCASE CHAMBER" for oil levelling of of compressors and or compression machines for fluids (vapor or gas) connected in paralell in the same circuit, characterized by the creation of a third chamber , called "Cranckcase Chamber" (8) - Figure 3. It is constructed a "dividing cover" (7) figure 3 or wall casted in the same body, which will be placed at the suction chamber (2), separating physically the Suction Chamber (2 ) properly said and the "Cranckcase Chamber" (8), object of this invention. A capillary tube for Gas Equalization (9) is connected in the same point of the Suction general manifold (10) in order to have practically the same suction pressure into the "Cranckcase Chamber" (8). The "Cranckcase Chamber" ' (8) has the specific purpose of storing lubricating oil; it ' shall have a volumetric capacity bigger than the v-olume of oil contained in it, allowing the free oscilation of the oil in its level (19). 2 - "CRANCKCASE CHAMBER" for oil levelling of compressors and or compression machines for fluids ( vapor or gas) connected in paralell in the same circuit,according to the claim one, characterized by a "capillary tube"( 9 ) figure 4, interrupted by a little calibrating hole (11). The "capillary tube" (9) is EXTERNALLY connected at the compressor intake (12) to the "Cranckcase Chamber" (8) in a point over the oil level (19). 3 - "CRANCKCASE CHAMBER" for oil levelling of compressors and or compression machines of fluids ( vapor or gases) connected in paralell in the same circuit , according to claims 1 and 2, characterized by a calibrating hole (13) INTERNALLY set up in the "dividing cover " (7) equalizating the suction chamber (2) pressure with the one of the "Cranckcase Chamber" (8) Figure 5.

Inventors: BASSEGGIO NARCIZO OSORIO, BASSEGGIO, NARCIZO, OSORIO
Applicants: BASSEGGIO NARCIZO OSORIO, BASSEGGIO, NARCIZO, OSORIO
Application year: 1986
Main classification: F04B39
IPC codes: F04B39