US 2820590 A
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Description (OCR text may contain errors)
Jan. 21, 1958 A. L. WALKER Filed Feb. 15, 1956 INVENTOR.
ARTHUR L. WALKER United States Patent CENTRIFUGE Arthur L. Walker, Tulsa, Okla.
Application February 13, 1956, Serial No. 565,143
9 Claims. (Cl. 233-26) This invention relates to a centrifuge. More specifically, it relates to a combination preheater and heated centrifuge tester of the class used to centrifuge impurities from samples of oil such as crude oil taken from lease stock tanks and the like for determining oil quality.
Sample preheater and centrifuge combinations have been proposed. Generally they preheat the sample and may maintain its temperature during the shake out in the centrifuge by electrical heaters. In field instruments to which this invention is particularly adapted, the electric load is not only too severe for standard automotive equipment but the capacity of the heating elements is of necessity so low that the processing of a sample requires too much time.
It is therefore an object of this invention to provide an improved combination sample preheater and heated centrifuge. A further object of this invention is to provide a combination sample preheater and heated centrifuge in which the heat is supplied by a hot fluid such as hot water from the cooling system of an internal combustion engine. A still more specific object of this invention is to provide means in a hot water heated sample centrifuge for circulating the hot water to a combination preheater. Other objects and advantages of this invention will become apparent from the following description. In this description reference will be made to the accompanying drawing which is a perspective View, partially in cross section, of a preferred embodiment of a centrifuge according to this invention.
This invention may be described, in brief, as a combination sample preheater and heated centrifuge in which hot fluid from the centrifuge heat source is circulated to the sample preheater.
Referring now to the accompanying drawing for a more detailed description of the invention, the housing 9, which is desirably cast from a dense, high heat capacity metal like iron, is divided generally by a deck member 10 into an upper compartment or centrifuge chamber 11 in which the samples are heated and centrifuged and a lower or heating compartment 12 in which a heating fluid is circulated. A motor housing 13 in the center of the centrifuge chamber and heating compartment is desirably cast integrally with the housing. A fractional horse power motor 14 is suspended within the motor housing by bolts 15. For safety a gasket 16 seals the joint between the motor and the motor housing to prevent combustible gases in the centrifuge chamber from entering the motor housing. The motor shaft 17 extends up out of the motor housing through a hole 18. A centrifuge head 19 is connected to the upper end of and rotated by the motor shaft. Metal shields 21 in which either the sample or the sample tubes are placed for a shake out are rotatably mounted in the head 19 on a horizontal axis which extends in the direction of rotation of the head. By this means the shields and/ or sample tubes rotate in a horizontal plane with the lower tips 22 extended to a peripheral position as well known in the art. Any number of the shields may be similarly attached to the centrifuge head so than any desired number of samples may be run simultaneously. A power conduit 23 to the motor extends under the bottom 24 of the Water compartment to a combination switch and rheostat 25 which controls the speed of the motor. The switch and rheostat are connected to a suitable power source such as the battery of an automobile to which the water system of the centrifuge is connected. A signal light 26 is connected in the motor power circuit to indicate for the convenience of the operator when the power is on. The control panel 27 on which the switch and rheostat and the signal light are located may be unitary with the housing as indicated in the drawing or it may be separately mounted. Preferably it is cast integral with the housing and located on what is considered the front of the centrifuge between two sample preheater wells 28. These wells are also preferably cast integral with the housing. Each well may have a lid 29.
An important feature of this invention is in the inclusion of these wells in the hot fluid circulating system of the centrifuge. Hot fluid from any suitable source, such as the cooling or exhaust systems of the automobile in which the centrifuge is carried is connected to the fluid inlet 31 of the centrifuge heating compartment 12. This hot fluid, which is typically hot water, is circulated through the enclosed heating compartment around the central motor housing 13 preferably by an external force pump such as the automobile water pump. A baflie 32 is provided in the centrifuge heating compartment to force the hot fluid out to each of the peripheral sample wells. These baffles are particularly important where hot water is employed as the heating medium since the wells are of necessity on the periphery of the housing where, due to centrifugal forces, the denser cold water would otherwise circulate. That is, cold water being substantially denser than hot water, but for the baffles the hottest water would circulate at the center near the motor housing and the coldest water would circulate near the periphery of the housing and the sample preheater wells. Obviously, to expedite or speed up a complete test, the sample must be heated to the test temperature as quickly as possible. Without the baflles to direct the hot water to the wells considerable time is lost each time a sample is heated. The sample containers may be placed in the wells in direct contact with the hot water. Desirably some means such as a cast inner compartment or a thimble tube sealed in the neck 33 of each well is provided to make the centrifuge insensitive to relative elevation changes between the hot water source and the centrifuge. Alternatively the sample containers themselves may be adapted to seal in the neck 33 of each well. The baflie thus causes the hot circulating fluid to come into indirect heat exchange with the sample by circulating the hot fluid preferably around and into intimate contact with the sample in each sample heater well. After circulating around the centrifuge heater compartment the cooled heating medium is discharged through fluid outlet 34. A partition 35 in the heating compartment separates the fluid inlet 31 and fluid outlet 34 causing the heating fluid to be circulated through the compartment around the motor housing baffles through the sample preheater wells, etc.
In operation according to the preferred procedure, the fluid inlet and fluid outlet which may both be provided with snap-on fittings such as Snap-Tite couplings, are respectively connected, desirably flexibly as by hoses, to hot and cold water connections in the cooling system of an automobile, the hot water connection being at a higher pressure than the cold water connection. That is, the fluid inlet to the centrifuge is typically connected to the auto mobile water pump discharge after the water has passed fliroughtlr'e block and before it has passed through the thermostat and the radiator. The fluid outlet is connected to the water cooling system on the downstream side of the thermostat and desirably on the downstream side of the radiator so that the resistance of the radiator and the force of the water pump cause the water to circulate through the heating compartment. The automobile thermostat or separate temperature control means in the centrifuge circulating system regulates the temperature in the centrifuge. Fluid heaters and circulating means other than those described may be provided. Power, typically electrical power, from the same automobile used to transport and heat the centrifuge, is connected to the centrifuge motor. This motor drives the centrifuge head 19 either directly or indirectly at ahigh speed, preferably at about 1700-1750 R. P. as required by A. S. T. M. standards.
The water is allowed to circulate through the heating compartment continuously so that the centrifuge is generally always up to temperature and ready for a sample to be run. The motor is run only during the actual cen trifuging or shake out operation. Standard samples are first placed in suitable tubes and deposited in the sample preheater wells. Here they are desirably heated to the standard centrifuging temperature of about 140 degrees Fahrenheit. The heating Water is preferably circulated either oythe automobile water pump or a special supplementary pump as the samples are preheated. After the samples are heated to centrifuging temperature they are placed in the centrifuge in metal shields 21. Motor 14 is thenstarted and the samples are centrifuged for the desired time as well known in the art. centrifuging operation the opening 36 in the housing 9 may be closed by a lid 37 so that the samples are maintained at the desired centrifuging temperature. At the end of the shake out the motor is stopped and the samples are withdrawn from the centrifuge for analysis as well knownin the art.
It can be seen from the foregoing that this invention is susceptible of a wide variety of modifications and embodiments and that it is not limited to the apparatus specifically described. This invention should therefore be construed to be limited not by the description but only by the scope of the appended claims.
1. A combination centrifuge and preheater comprising a housing, means to rotate a sample in the upper part of said housing, means in the bottom of said housing forming a reservoir for hot fluid, means to circulate said hot fluid in said reservoir, a sample preheater in fluid communication with said reservoir, and baflie means in said reservoir to cause said hot fluid to circulate past said sample preheater.
2. A combination sample centrifuge and preheater comprising a centrifuge housing, means to rotate a sample in the upper part of said housing, means in the bottom of said housing forming a reservoir for hot liquid, means to circulate said hot liquid in said reservoir, a sample preheater in the periphery of said housing in fluid communication with said reservoir to cause said hot liquid to circulate past said sample preheater.
During the actual 3. A combination sample centrifuge and preheater according to claim 2 including divider means between said.
upper part of said housing and said reservoir.
4. A combination preheater and centrifuge for a sample comprising a housing, a centrifuge chamber in said housing, a heating compartment in said housing beneath said centrifuge chamber for the circulation of a-heating fluid to heat said centrifuge chamber, means to rotate a sample in said centrifuge chamber at high velocity, at least one sample well in the periphery of said housing in fluid com munication with said heating compart'rnent,and means in saidhe'ating compartment :to cause hot fluids circulating therein to intimately contact said sample vwell whereby said sample Well is heated by -a heating fluid circulating in said heating compartment.
5. A combination according to claim 4 in which said means in said heating compartment to cause hot fluids circulating therein to intimately contact said sample well comprises a baiile. v
6. A combination preheater and centrifugal tester comprising ahousing, a centrifuge chamber in said housing, .a heating compartment in said housing beneath said centrifuge chamber for the circulation of a heating fluid to heat said centrifuge chamber, means to-rotate a sample .in'
said centrifuge chamber, a multiplicity of sample preheater wells at the periphery of said housing in fluid com.- munication with said heating compartment, a fluid inlet to said heating compartment, a fluid outlet to said heating compartment adjacent to said fluid irilet, a substantially radial partition in said heating compartment between said fluid inlet and said fluid outletand baflie means insaid heating compartment connected at the center of said housing with said partition and extending substantially radially to each of said sample vpreheater wells to direct circulating fluid from said fluid inlet past each of said sample preheater wells around said heating compartment to said fluid outlet.
7. A combination according to claim 6 including means to seal said sample preheater wells whereby said wells and said heating compartment are completely enclosed.
8. In a heated centrifuge including a housing, a centrifuge chamber in said housing, means to rotate a sample in said chamber, and a heating compartment in said housing beneath said chamber for circulating a fluid to heat said chamber, the improvement comprising a sample preheater well in the periphery of said housing in fluid communication with said compartment, and means to cause a fluid in said compartment to circulate past said well.
9. A combination centrifuge and preheater comprising a housing, means to rotate a sample in the upper part of said housing, means in the bottom of said housing forming a reservoir for hot fluid, means to circulate said hot fluid in said reservoir, and a sample preheater in fluid communication with said reservoir.
References Cited in the file of this patent UNITED STATES PATENTS 1,959,208 Kittelson -a May 15, 1934