HEATING APPARATUS AND METHOD FOR INDUSTRIAL USE

Abstract

An industrial apparatus has a circuit (2) in which an operating fluid circulates. The circuit (2) has a means (20) for heating the operating fluid and being deprived of an evaporator, and a circulating line (31) in which a heat transfer fluid circulates; the circulating line (31) being closed on itself; the flow rate of the heat transfer fluid in the circulating line (31) being between 10 and 500 m.sup.3/h. A first heat exchanger (901) places the circuit (2) and the circulating line (31) in thermal communication. An industrial heater (92) has a second heat exchanger (902) in which the circulating line (31) passes, wherein the heating means (20) has a piston pump (21).

Claims

1. An industrial apparatus comprising: a circuit in which an operating fluid circulates; said circuit comprising a means for heating the operating fluid and being deprived of an evaporator, a circulating line in which a heat transfer fluid circulates; the circulating line being closed on itself; the flow rate of the heat transfer fluid in said circulating line being between 10 and 500 m.sup.3/h, a first heat exchanger; the first heat exchanger placing said circuit and said circulating line in thermal communication, an industrial heater comprising a second heat exchanger in which the circulating line passes, wherein the heating means includes a piston pump.

2. The apparatus according to claim 1, wherein said heat transfer fluid is other than water.

3. The apparatus according to claim 1, wherein said first heat exchanger is a tube bundle exchanger.

4. The apparatus according to claim 1, wherein said apparatus comprises a capacity control means for controlling the flow rate of the operating fluid in the circuit; said capacity control means comprising a motorised valve situated along the circuit.

5. The apparatus according to claim 1, wherein said apparatus comprises a steam generator; or a dryer; that in turn comprises said heater, which receives heat from the circulating line and uses the heat for a predetermined process.

6. The apparatus according to claim 1, wherein said apparatus comprises a distiller; or an emulsifier; or a pasteuriser that in turn comprises said heater, which receives heat from the circulating line and uses the heat for a predetermined process.

7. The apparatus according to claim 1, wherein said apparatus comprises a reactor for carrying out a chemical reaction; said reactor in turn comprises said heater, which receives heat from the circulating line and uses the heat for a predetermined process.

8. The apparatus according to claim 1, wherein said apparatus comprises an electric motor for driving the piston pump; said electric motor comprising/being a magnetic asynchronous electric motor.

9. The apparatus according to claim 1, wherein the operating fluid is R1233ZD(E).

10. The apparatus according claim 1, wherein said apparatus comprises a control unit for regulating the temperatures and pressure required to keep in a liquid phase the operating fluid circulating in circuit.

11. A heating method involving the apparatus according to claim 1, comprising the following steps: circulating a operating fluid in the circuit; heating the operating fluid that circulates in said circuit; carrying out a transmission of heat from the operating fluid to the heat transfer fluid that recirculates in the first circulating line, providing the heat coming from the heat transfer fluid in the heater situated along the circulating line.

12. The method according to claim 11, wherein the operating fluid has a pressure between 6 and 8 bar.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Additional features and advantages of the present invention will emerge more clearly from the approximate, and thus non-limiting, description of a preferred but not exclusive embodiment of a heating apparatus and method, as schematically illustrated in FIG. 1.

DETAILED DESCRIPTION

[0030] In the appended FIGURES, an industrial heating apparatus is denoted by the reference number 1.

[0031] The apparatus 1 comprises a circuit 2 in which an operating fluid circulates.

[0032] The operating fluid can be an HFO fluid (hydrofluoroolefin-based fluid) such as, for example, R1366Mzz or R1233 ZD or an ammonia- or inhibited calcium carbonate-based one or still others. It is advantageously R1233ZD(E). Conveniently, the operating fluid in the circuit 2 always remains in the liquid phase and advantageously between 6 and 8 bar. Conveniently, the flow rate of the operating fluid in the circuit 2 is comprised between 20 and 500 m.sup.3/h (cubic metres/hour).

[0033] The circuit 2 comprises a means 20 for heating the operating fluid. The heating means 20 will be better described below. The circuit 2 defines a heat pump.

[0034] The apparatus 1 comprises a line 31 for circulating a heat transfer fluid. The volumetric flow rate of the heat transfer fluid in said line 31 is advantageously greater than 10 m.sup.3/h; it is preferably greater than 30 m.sup.3/h. Conveniently, the volumetric flow rate of the heat transfer fluid is less than 500 m.sup.3/h; it is advantageously less than 200 m.sup.3/h, even more preferably less than 150 m.sup.3/h. Preferably, the line 31 defines a path closed on itself. It is thus a recirculation line.

[0035] The apparatus 1 comprises a first heat exchange means 5 between the circuit 2 and the circulating line 31. The first heat exchange means 5 comprises a first heat exchanger 901. The first heat exchanger 901 places the circuit 2 and the line 31 in thermal communication. Therefore, the first exchanger 901 places the operating fluid that circulates in the circuit 2 in thermal communication with the heat transfer fluid that circulates in the line 31. As exemplified in FIG. 1, the first exchanger 901 is a tube bundle exchanger. This solution is particularly advantageous, as in industrial applications, it is important to have substantial flow rates. In an alternative solution, it could be a plate exchanger.

[0036] Conveniently, the heat transfer fluid in the line 31 always remains in the liquid state. Conveniently, the heat transfer fluid is other than water.

[0037] Advantageously, the heat transfer fluid is an HFO fluid (hydrofluoroolefin-based fluid) such as, for example, R1366Mzz or R1233 ZD-E or an ammonia- or inhibited calcium carbonate-based one or still others. It is advantageously R1233ZD(E).

[0038] In a particular operating mode, the operating fluid in the first exchanger 901 undergoes a temperature change of between 35 and 85 C. The operating fluid cools in the first exchanger 901 and heats the heat transfer fluid that circulates in the line 31.

[0039] Conveniently, the apparatus 1 comprises a capacity control means 93 for controlling the flow rate of the operating fluid in the circuit 2. The capacity control means 93 comprises a motorised valve 930 situated along the circuit 2. The motorised valve 930 is preferably remotely actuated. For this purpose, it has a special electrically driven actuator (for example there can be a motor or an electromagnet). The valve 930 can be actuated by an operator or by a pressure sensor along the circuit 2 to keep in a liquid phase the operating fluid circulating in circuit.

[0040] Conveniently, the motorised valve 930 is located downstream of the first exchanger 901 and upstream of the heating means 20.

[0041] As exemplified in FIG. 1, the heating means 20, the motorised valve 930 and the first heat exchanger 901 are arranged in series along the circuit 2.

[0042] Along the line 31, the apparatus 1 can comprise a recirculation pump for the heat transfer fluid. The water recirculation pump is typically a centrifugal pump. It allows the heat transfer fluid to be recirculated along the line 31.

[0043] The heating means 20 is a piston pump 21. It is typically a high-pressure piston pump 21. The apparatus 1 can be considered a heat pump in that sense that it has a COP greater than 7, preferably greater than 10. The COP (Coefficient of Performance) is an index of the efficiency of a heat pump and is given by the ratio between the energy delivered and the electricity consumed. Nevertheless, contrary to a standard heating pump, the system of the invention does not comprise evaporator.

[0044] The pump 21 thus brings about a heating of the operating fluid. This occurs by virtue of the action on the uncompressible operating fluid. This action forces the operating fluid along the conduits of the pump 21, bringing about an increase in kinetic energy and heating of the fluid by friction.

[0045] Conveniently, the circuit 2 comprises only said piston pump 21 to heat the operating fluid circulating inside it.

[0046] The piston pump 21 is a volumetric pump of a known type, if considered in itself. The piston pump could be an axial piston pump, but also a piston pump of another type. For example, it comprises pistons housed in corresponding pumping chambers. Advantageously, the pump 21 comprises more than three pistons. The pumping chambers are conveniently integrated in a body that can be set in rotation. The rotation of this body and thus of the pumping chambers draws the pistons in rotation and thus brings about an alternating back and forth motion of the pistons in the corresponding pumping chambers. In fact, the pistons have an end pressed by an elastic means against a plate that is inclined with respect to the axis of rotation of the pumping chambers. The apparatus 1 comprises an electric motor 22 for driving the piston pump 21. The electric motor 22 preferably comprises/is a magnetic asynchronous electric motor 22. This facilitates the low-noise operation of the apparatus 1. Conveniently, the motor 22 comprises an inverter. The operation of the motor 22 is also regulated as a function of the feedback provided by the temperature probe 321 situated along the line 31.

[0047] The apparatus 1 can comprise a filter 61 and a sight glass 62. Conveniently, they are disposed downstream of the first exchanger 901 and upstream of the piston pump 21.

[0048] The apparatus 1 conveniently comprises a soundproof casing housing the piston pump 21 inside it.

[0049] The apparatus 1 also comprises a central control unit for controlling overall operation and regulating the required temperatures and pressure required to keep in a liquid phase the operating fluid circulating in circuit 2.

[0050] The apparatus 1 also comprises an industrial heater 92. The heater 92 comprises a second exchanger 902. The circulating line 31 passes in the second exchanger 902. The circulating line 31 thus conveys the heat transfer fluid from the first to the second exchanger 901, 902 and enables the return thereof from the second exchanger 902 to the first exchanger 901. This along a closed path. The second exchanger 902 is therefore disposed along the circulating line 31. The heat transfer fluid is cooled in the second exchanger 902. The line 31 thus defines the hot side of the second exchanger 902. The cold side can be a conduit in which a further fluid circulates or an environment in which the released heat triggers a process. The second heat exchanger 902 could thus release heat into an environment or transfer it to a further fluid to be heated. Conveniently, the heat transfer fluid is a liquid and remains liquid along the entire path of the line 31.

[0051] The heat transfer fluid thus carries to the heater 92 at least part of the heat that is generated in the circuit 2 by the pump 21 and will then be used by the industrial apparatus 1.

[0052] The apparatus 1 can in fact comprise, by way of non-exhaustive example, one of the following devices: [0053] a steam generator, or [0054] a dryer; or [0055] a distiller; or [0056] an emulsifier; or [0057] a pasteuriser; or [0058] a reactor for carrying out a chemical reaction.

[0059] Said device in turn comprises the heater 92 in order to receive heat from the circulating line 31. The heat thus obtained is used to carry out the dedicated processes of each device. The device can therefore be defined as an industrial thermal treatment device.

[0060] The present invention also relates to a heating method used in an industrial apparatus.

[0061] The method is advantageously implemented by an apparatus 1 having one or more of the above-described features.

[0062] The method comprises the following steps: [0063] circulating an operating fluid in a circuit 2; conveniently, the operating fluid always remains liquid while recirculating inside the circuit 2 (one could thus also speak of operating liquid); [0064] heating the operating fluid that circulates in the circuit 2.

[0065] The step of heating the operating fluid that flows in the circuit 2 takes place during the passage of the operating fluid in a piston pump 21 situated along the circuit 2.

[0066] The piston pump 21 thus heats the operating fluid. Conveniently, at least at the pump 21 (but preferably everywhere), the operating fluid is liquid. The piston pump 21 acts on said operating fluid, bringing about an increase in pressure comprised between 11 and 50 bar, between 6 to 8 bar for example when R1233ZD(E) is used, and/or a rise in temperature of at least 100 C. Downstream of the piston pump 21, temperatures for the operating fluid even higher than 110 C. or 165 C. can be obtained. In addition to bringing about the heating of the operating fluid, the pump 21 is also solely responsible for the movement thereof.

[0067] The method comprises a step of carrying out a transmission of heat from the operating fluid to a heat transfer fluid that recirculates in a first circulating line 31. This takes place by means of a first exchanger 901.

[0068] Conveniently, the method comprises the step of providing the heat coming from the heat transfer fluid in a heater 92 situated along the circulating line 31. The heater 92 uses that heat to carry out specific operations. The heater 92 in fact comprises a second heat exchanger. For example, the heater 92 could be integrated in a steam generator. In that case, the heat carried by the heat transfer fluid through the second exchanger 902 is used to produce steam.

[0069] Or the heater could be a dryer and the heat is used to dry food (or non-food) products positionable in an environment.

[0070] Or, in the case of a distiller, the heat could be used to favour passages of state and to separate chemical components.

[0071] Or, in the case of a pasteuriser, the heat could be used to treat raw materials and fresh semi-processed products, at a temperature such as to considerably reduce the bacterial load, while preserving the nutritional properties of the foods.

[0072] The present invention achieves important advantages.

[0073] First, it enables noteworthy heating performances to be obtained. Furthermore, it enables maintenance to be facilitated.

[0074] It is also possible to obtain a compact, low-noise solution.

[0075] The invention thus conceived is susceptible of numerous modifications and variants, all falling within the scope of the inventive concept that characterises it. Furthermore, all the details may be replaced with other technically equivalent elements. All the materials used, as well as the dimensions, may in practice be any whatsoever according to needs.