Hood with condenser for commercial oven, particularly combination steam-convection oven

Abstract

The subject of present invention is a hood with a condenser for a commercial oven, particularly a combination steam-convection oven, comprising a housing, an air inlet for supplying cooling air from the outside, a fan drawing in the cooling air through the air inlet, a cooling air outlet for expelling the air drawn in by the fan, a steam condenser in the form of a heat exchanger with a coil having at least one inlet opening for supplying steam from the inside of a commercial oven to the coil and at least one outlet opening for draining the condensate coming out of the coil, characterised in that it comprises a radial fan (3) that blows cooling air radially onto the at least one coil (5) surrounding the fan (3), wherein the at least one coil (5) surrounding the fan having an external finning (6).

Claims

1. A hood for a commercial oven, the hood comprising a housing, an air inlet for supplying cooling air from outside, a cooling air outlet for expelling the cooling air drawn into the air inlet, a steam condenser comprising a heat exchanger with a coil having an inlet opening for supplying steam from the inside of the commercial oven to the coil and an outlet opening for draining condensate from the coil, and a radial fan for blowing the cooling air radially onto the coil surrounding the radial fan, the coil having an external fin.

2. The hood according to claim 1, wherein the external fin comprises a helical surface.

3. The hood according to claim 2, wherein the external fin comprises rings along the pipe forming the coil.

4. The hood according to claim 1, wherein the radial fan with comprises a rotor with a substantially vertical axis of rotation.

5. The hood according to claim 1, wherein the coil surrounding the radial fan comprises a pipe coiled in a helix having a substantially vertical axis, the inlet opening being located in an upper part of the coil above the outlet opening for the condensate in accordance with a direction of steam flow through the coil.

6. The hood according to claim 1, wherein the inlet opening and the outlet opening are connected by a collector, which is divided by a baffle extending downwards to a condensate tray and having a connector inserted into the space inside the collector on a side of the inlet opening so that an upper part of the connector defines an overflow level for condensate coming out through the outlet opening, wherein the baffle together with the condensate accumulating in the tray prevent the steam from escaping through the outlet opening back to the inlet opening.

7. The hood according to claim 6, wherein the collector is connected to an exhaust funnel, in which the steam, after passing through the coil, is expelled outside, the connection of the exhaust funnel being located on a side of the outlet opening and above the overflow level.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In the following the invention will be illustrated in a preferred embodiment with reference to the attached drawings, wherein:

(2) FIG. 1 shows the hood in a side cross-sectional view (arrows indicate the air flow);

(3) FIG. 2 shows the hood in a back view in cross-section through the collector connecting the coils (arrows indicate the steam flow);

(4) FIG. 3 shows the hood in a second side view (arrows indicate the flow of uncondensed steam residues);

(5) FIG. 4 shows the coil with external finning and the magnified helical surface (detail B);

(6) FIG. 5 shows the heat exchanger in the form of a continuous coil coiled in a helix;

(7) FIG. 6 shows the heat exchanger composed of three separate coils connected via a common collector;

(8) FIG. 7 shows the collector connecting the inlet and outlet openings of the heat exchanger coils;

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION

(9) FIGS. 1-3 show the hood cooperating with a combi steamer. The hood has a generally rectangular housing 1 with a front hood 12 comprising an air inlet with installed filters 13. Behind the air inlet there is a suction chamber 2. Above the suction chamber 2 there is a radial fan 3 with a rotor with a vertical axis of rotation. A steam condenser in the form of an air-air (steam) heat exchanger 4 is arranged around the radial fan 3. The heat exchanger 4 is in the form of a coil 5 shaped as a coiled cylindrical pipe, equipped with an inlet opening 7 for supplying steam from the oven inside and an outlet opening 8 for draining the condensate. The upper part of the housing 1 comprises exhaust vents 14 through which the cooling air drawn in by the radial fan 3 is expelled.

(10) The coil 5 shown in FIG. 4 is in the form of a cylindrical pipe with an external finning 6 shaped as a square thread or in the form of rings. Preferably, the coil 5 surrounding the radial fan 3 is shaped as a pipe coiled in a helix, and its inlet opening 7 is arranged above the outlet opening 8 and is located in the upper part of the heat exchanger 4. Such shape of the heat exchanger 4 results in gravitational condensate and steam flows from the inlet opening 7 towards the outlet opening 8. The pitch of the coil helix 5 can be from 0 to 1.5 of the coil diameter. In the case the coil 5 is not coiled in a helix (FIG. 6) and the pitch is 0 (or the coil 5 is coiled in a helix, but with a very small pitch, smaller than the diameter of the coil), the heat exchanger 4 can be composed of one or more such elements connected by a common collector. However, when the coil 5 is coiled in a helix (FIG. 5), with a pitch equal to or greater than the diameter of the coil 5, preferably from 1 to 1.5 in diameter, then the heat exchanger 4 is in the form of a multi-turn coil 5 in the form of one, continuous element.

(11) In the presented example, the heat exchanger 4 consists of three independent coils 5 connected by a common collector 9, but the heat exchanger 4 can also have the form of a coil 5 made as a single continuous section of pipe.

(12) The steam supplying inlet openings 7 and the outlet openings 8 through which the condensate or possibly the uncondensed steam residues escape, are connected by a cylindrical common collector 9, arranged vertically, which is illustrated in more detail in FIG. 7. The collector 9 is divided from above by a baffle 11 extending downwards to the condensate tray at the bottom of the collector 9. The baffle 11 divides the collector 9 into two spaces separating the inlet openings 7 from the outlet openings 8. In other words, on one side of the baffle 11 there are only inlet openings 7, and on the other side the outlet openings 8 only. In the bottom of the collector 9 a connector 10 is provided, which enters the space inside the collector 10 on the side of the inlet openings so that the upper part of the connector 10 defines the overflow level for the condensate coming out through the outlet openings 8 and accumulating in the tray on the collector bottom 9. The baffle 11 together with the condensate accumulating in the tray prevent the steam coming out through the outlet openings 8 from getting back into the inlet openings 7 for the steam coming out from the oven. In addition, the collector 9 is connected to exhaust funnels 15, through which the uncondensed steam, after passing through the coil 5, is discharged outside, wherein the exhaust funnel connection 15 is provided in the collector 9 on the side of outlet openings 8, above the overflow level.

(13) The air entering the hood passes through the filters 13 installed on the air inlet in the front hood 12, and then still cool (at ambient temperature) passes through the radial fan 3 and comes out of it, evenly feeding the heat exchanger 4, which is wrapped spirally around the radial fan 3. Positioning the radial fan 3 in the airflow upstream the heat exchanger 4 protects it from overheating.