WO1998032536A1

WO1998032536A1 - Thermostat

Info

Publication number: WO1998032536A1
Application number: PCT/RU1997/000137
Authority: WO
Inventors: Mikhail Nikolaevich Kazansky
Original assignee: FRAEVA TATIYANA GRIGORIEVNA
Current assignee: FRAEVA TATIYANA GRIGORIEVNA
Priority date: 1997-01-23
Filing date: 1997-05-06
Publication date: 1998-07-30
Anticipated expiration: 1999-07-23

Abstract

The invention relates to devices for producing a desired temperature in a closed-type working space and maintaining obtained temperature for a predetermined period of time. The thermostat contains a heater (2), a blower (3), an airduct, a temperature sensor (4) an electronic temperature controller (5) and a control panel (9). All above-stated members are assembled and plugged into one housing (1) to form a completely self-contained device which may be placed in various thermal working spaces. The sensor (4) is located in the suction chamber (7) of the airduct and attached to the electronic controller (5) in which the side opposite from that side to which the sensor (4) is attached forms the control panel (9). The invention may find use in biotechnology, medicine, microbiology, chemistry, food and pharmaceutical industries for producing optimal temperatures for cultivation microorganisms, plant and animal cells and other procedures.

Description

THERMOSTAT

Technical Field

The present invention relates generally to devices for producing a desired temperature within a closed-type working space and for Keeping this temperature during a required period of time and relates more particularly to a thermostat.

It has particular reference to an improved type of thermostats which are used in biotechnology, micπb ology and medicine, for instance, for cultivation microorganisms, plant and animal cells.

In addition the invention can be used in chemistry and food industry where many procedures require for maintaining a strictly preset temperature.

Background Art There exists many varieties of thermostats comprising a heat insulating chamber accomodating a blower to provide air circulation, a heating or cooling element and an airduct. The thermostats of such construction are disclosed in SU Author's Certificate Publication II 371934 (01.03.1973) and in DE Application Publication N 4116500 (26.11.1992).

Known in also a thermostat disclosed in SU Author's Certificate PuDlication N 485428 (25.09.1975) comprising a heat insulating nousmg accomodating a heating element, a blower and an air-circulation controller. During the heating period said controller provides air circulation in the housing with flowing the circulated air around the heating element. While during the cooling period said controller provides air flow entering and exit, after its travelling througn the housing.

The another prior art thermostat disclosed in SU Author's Certificate Publication N 246892 (20.06.1969) comprises a heat insulating housing adapted to place a blower and temperature sensors which provide the heat removal control.

In another prior art thermostat in DE Application Publication N 0019828 provided with a neat insulating chamber containing a heater, a biower ano a temoerature sensor, the control panel is c osely aαiacent to one of the chamber walls. The thermostat disclosed in said Publication nas much in common with the invented thermostat. The common features: availib lity of a neater, blower, airduct, temperature sensor, electronic controller and control panel.

All above-said known thermostats are adapted for use in definite and carticular thermal working spaces; some of said thermostat elements being mounted on the walls of a thermal cnamber.

But above-said solutions cannot readily be adopted in case cf cultivation of microorganisms, plant and animal cells where it is often desired to provide thermal conditions for a variety of working spaces and at the same time these worκιng spaces don't require a specia. heat insulation as the temperature within said working spaces does not significantly differ from the evironmental temperature.

In addition the use of advanced weak-current electronic regulators ensuring precision control of temperature in thermostats sets the task of providing the possibility to reduce the troubles generated at the heater starting and stopping. This disadvantage can be eliminated by compact mounting of electric components of the thermostat.

Thus our a m s to create a compact, inexpensive, high-precision ano general-purpose thermostat.

Disclosure of Invention It is therefore a principal object of this invention to construct tne apparatus in such manner tnat the thermostat may operate in different temDerature-controlled working spaces. According to the invention there is provided a thermostat adapted to produce and keep a desired temperature in a thermal working space, containing a heater, blower, airduct, temperature sensor, electronic controller and a control panel. According to the invention all sa d elements are assembled ano mounted m one housing to form a completely self-contained device which can be fast replaced into another orαng space if a problem should ever occur. One of the characteristic features consists in mounting said temperature sensor in a suction chamber of the airduct and in its attaching on the electronic controller in which the opposite side from the side with the sensor attached forms a control panel.

According to the invention the thermostat s completely self-contained and general-purpose, it can be placed in any airtight temperature-controlled working space closed by walls. The walls may be made of polyecnylene film. In addition the thermostat is extremely compact, high-precision, almost free of wires and as a result free of electrical interferences. It is of small dimensions, light weight, inexpensive and economical.

Brief description of the drowmgs

For better understanding the invention a particular embodiment of the device of the present invention will be described with reference to the accompanying drawing. The drawing shows a diagrammatic sectional view of the thermostat.

In the drawing the elements has following numbers :

1 - housing;

2 - heater;

3 - blower;

4 - temperature sensor;

5 - electronic temperature controller;

6 - windows;

7 - suction chamber of airduct;

8 - discharge chamber of airduct;

9 - control panel;

10 - starter button;

11 - switch;

12 - handle for adjusting pre-set temperature value;

13 - digital indicator displaying temperature value;;

14 - wiring for blower;

15 - wiring for heater; 16 - lower shutter; l¹ - fastening screws of lower shutter;

18 - additional window;

19 - upper shutter;

20 - electric wiring;

21 - bell;

22 - bell leg;

23 - fastening screw of bell leg.

Description of preffered embodiment of the invention

The novel thermostat comprises a housing 1 adapted the place a heater 2, a blower 3, a temperature sensor 4 and an electronic temperature controller 5. The housing is made of electrically insulating material (may be faience) and has a shape of a vertical tube the middle part of which s equipped with a window 6 and an internal cavity of which forms an airduct 8. The blower 3 mounted on the airduct 7 separates said airduct into an upper suction chamber 7 and lower discharge chamoer 8. The heater 2 is placed m the discharge chamber 8 while the sensor 4 is m the suction chamber in line with a window 6 through which the air is sucked nto the housing.

The sensor 4 is attached to the electronic temperature controller 5 which serves for energizing or deenergizmg the heater 2 according to the indications of the sensor 4. The upper surface of the electronic controller 5 opposite to the surface on which the sensor 4 is placed s shaped as a panel 9. The panel 9 carries control and indication handles: a starter button 10, a switch 11, a handle 12 for adjusting the pre-set temperature value and a digital indicator 13 to display the temperature value. Electronic temperature controller 5 is connected through a wiring 14 to the blower 3 and through a wiring 15 to the heater 2.

The shutter 16 is mounted on the window 6 through screws 1". The upper portion of the housing 1 has an additional window 18 with a sut- ter 19.

Power to tne temperature controller 5 is applied through a wiring 20.

As the housing 1 is interlocked with all above-stated components 2-20 it forms one completely self-contained device wh cn may functions independently: heats the a r to a desired temperature, holds the temperature thus obtained and mixes the air mass in symmetrical air flows to reduce the temperature gradient. Because of this tne above-said de- vice may be placed in any airtight thermal working space closed by walls. In the given embodiment of the invention the device is centrally placed m a glass-made bell 21. The bell 21 is supported on three legs 22 equipped with screws 23 to provide a clearance between the bell and bell table (not shown) .

In operation the thermostat is energized through the wiring 20, the starter button 10 is pushed to actuate the controller 5, the switch 11 is set to the "programm" position, the handle 12 is rotated to display a numoer on the digital indicator 13 corresponding to the value previously determinated to be optimum for a given procedure, the switch 11 is set to the "operation" position and the thermostat starts to operate. The operation thereafter is fully automatic: the electronic controller actuates the blower 3 and the heater 2. The blower 3 generates a central descending air flow which being reflected from the bottom (not snown) thereafter flows up as a peripheral ascending flow to be further introduced into the suction chamber 7 of the airduct. The contacting action of the heater 2 with the central descending air flow occurred in the discharge chamber 8 results m a rise of the air temperature.

The temperature of the air the thermal working space is indicated by the sensor 4. When the temperature approaches the pre-set temperature the electronic controller 5 automatically lowers the power applied to the heater 2 thus decreasing the air heating velocity. When the temperature within the thermal working space is reached the pre-set temperature the electronic controller 5 automatically deener- gized the heater 2 with the blower to be operated. When the sensor 4 indicates that the temperature in the working space is reduced by 0.1 C from the pre-set value in result of heat losses the electronic controller actuates the heater 2 for a period sufficient to increase the temperature up to the pre-set value. At any moment the operator may check the difference between the actual and pre-set temperatures. It is merely necessary for the operator to change the switch from "operation" position to "programm" position and compare the indications. The difference must not be more than 0.1 C.

In order to provide the temperature in the working space close to the environmental temperature (1-3 C) it is merely necessary for the operator to move shutters 16 and 19 to close the windows 6 and open the windows 18. Simultaneously the operator turns the legs 22 to provide a clearance between the lower edge of the bell 21 and bell table (not snown) . The other actions of the operator are similar to those described previously.

Industrial applicability

The thermostat can be used for research purposes in biotechnology, microDiology, medicine, pharmaceutical and food industries for various procedures including cultivation of microorganisms, plant and animal cells. In addition it can find an application in chemistry and in the field of health protection in those procedures where close temperature control is essential.

Such features of the device as versatility and high precision ensures the best reliability in researches as compared with the conventional devices of this type. Therefore the device is especially attractive for those laboratories which deal with new technologies and preparations .

Claims

Claim

The thermostat used to produce and to maintain a desired temperature within a thermal working space containing a heater (2), a blower (3), an airduct, a temperature sensor (4), an electronic controller (5) and a control panel (9) c h a r a c t e r i z e d in that all said elements are assembled and plugged into one housing to form one completely self-contained device with a possibility to be placed in various thermal working spaces in which said temperature sensor (4) is located in a suction chamber (7) of the airduct and attached to the electronic controller (5) in which the side opposite from the side to which the sensor (4) is attached forms the control panel (9).