GB2145803A

GB2145803A - Vertical tube boiler

Info

Publication number: GB2145803A
Application number: GB08323410A
Authority: GB
Inventors: Maurice Edward George Maton
Original assignee: Individual
Current assignee: Individual
Priority date: 1983-09-01
Filing date: 1983-09-01
Publication date: 1985-04-03
Also published as: GB8323410D0; GB2145803B

Abstract

A vertical tube boiler having a plurality of vertical tubes 17 which extend through a water tank 10 and communicate with a combustion chamber 15 and a chamber 13 provided with a flue outlet 14, the tank 10 being provided with a transverse plate 19 located above the bottom or firing plate 12 of the tank and provided with holes through which the tubes 17 extend with a clearance gap being provided between the periphery of each hole and the outside of the associated tube 17, through which gaps water flows upwardly to create upward currents in the water within the tank 10 to hold any scale removed from the outside of the tubes 17 in suspension and if such scale drops to the bottom of the tank, then it accumulates on the plate 19 and not on the firing plate 12 thus preventing burning out of the firing plate 12. <IMAGE>

Description

SPECIFICATION Vertical tube boiler This invention relates to a vertical tube boiler.

Vertical tube boilers have a plurality of vertical tubes which extend from a combustion chamber, through the water tank and terminate in an upper chamber to which the exhaust flue is connected. A disadvantage of known boilers of this type is that any scale which is removed from the outside of the vertical tubes falls onto the upper side of the firing plate which defines the upper wall of the combustion chamber and the lower wall of the water tank and this causes the firing plate to become overheated at localised regions and the firing plate burns out and has to be replaced which is an expensive operation.

According to the present invention there is provided a vertical tube boiler comprising a plurality of vertical tubes which extend from a combustion chamber, through a water tank to an upper chamber provided with a flue outlet, a secondary plate being provided in the tank above and vertically spaced from a firing plate which forms the bottom wall of the tank and the upper wall of the combustion chamber, said tubes extending through holes provided in said secondary plate with a gap being formed between the outside surfaces of the tubes and the periphery of the holes in said secondary plate, means for supplying water into the space formed between the secondary plate and the firing plate, said water being caused to flow upwardly through said gaps.

The upward flow of water through said gaps creates an upward current to cause any scale removed from the tubes to be held in suspension in the water. If any removed scale does descend to the bottom of the tank then it collects on the secondary plate and not on the firing plate.

An embodiment of the invention will now be described, by way of an example, with reference to the accompanying drawing, in which: Figure 1 is a longitudinai section through a vertical tube boiler according to the present invention, Figure 2 is a plan view of the boiler, Figure 3 is a cross-section through the boiler taken along the line 3-3 indicated in Fig. 1, and Figure 4 is a cross-section taken along the line 4-4 indicated in Fig. 1.

The vertical tube boiler comprises water tank 10 having an upper wail 11 and a bottom wall 1 2 usually referred to as the firing plate. Located above the upper wall 11 is an upper chamber 1 3 provided with a flue outlet 14. Located beneath the firing plate 1 2 is a combustion chamber 1 5. The combustion chamber 1 5 is provided with fuel burners 1 6.

Extending between the chambers 1 3 and 1 5 are a plurality of vertical tubes 1 7 through which the hot combustion gases flow. Each tube 1 7 may contain turbulator means which cause the gases to scrub against the inner surface of the tube 1 7. The tank 10 is surrounded by heat insulating means 1 8.

Located within the tank 10 is a secondary transverse plate 1 9 provided with a plurality of holes 20 through which the tubes 1 7 extend with a clearance gap between the periphery of each hole 20 and the outside of the associated tube 1 7. An inlet conduit 21 is connected to the tank 10 in the region between the plate 1 9 and the plate 1 2. An outlet conduit 22 is connected to the upper end region of the tank 10. A circulating pump 23 is provided in the flow circuit between the conduits 21 and 22. The pump 23 may be an existing circulating pump or a secondary pump. The gap between the peripheries of the holes 20 and the tubes 1 7 may be approximately 5 millimetres.

In use of the boiler the water which flows through the inlet conduit 21 creates an upward flow through the gaps surrounding the tubes 1 7 and this flow creates upward currents which hold any scale removed from the outside of the tubes 1 7 in suspension in the water. If any scale drops to the bottom of the tank 10 then it accumulates on the secondary plate 1 9 and does not contact the firing plate 12.

With such an arrangement there is little or no temperature stratification within the water contained in the tank 10 and therefore a temperature sensing control device 24 can be located at any desired position. An over temperature control 25 is provided at the upper end of the tank 1 0. The pressure within the chamber formed between the plate 1 2 and plate 1 9 is that produced by the head of water plus the circulating pressure produced by the pump 23.

Even when the boiler is inoperative the pump 23 continues to operate and thus there is always a flow through the gaps surrounding the tubes 17.

1. A vertical tube boiler comprising a plurality of vertical tubes which extend from a combustion chamber, through a water tank to an upper chamber provided with a flue outlet, a secondary plate being provided in the tank above and vertically spaced from a firing plate which forms the bottom wall of the tank and the upper wall of the combustion chamber, said tubes extending through holes provided in said secondary plate with a gap being formed between the outside surfaces of the tubes and the periphery of the holes in said secondary plate, means for supplying water into the space formed between the secondary plate and the firing plate, said water being caused to flow upwardly through said gaps.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Vertical tube boiler This invention relates to a vertical tube boiler. Vertical tube boilers have a plurality of vertical tubes which extend from a combustion chamber, through the water tank and terminate in an upper chamber to which the exhaust flue is connected. A disadvantage of known boilers of this type is that any scale which is removed from the outside of the vertical tubes falls onto the upper side of the firing plate which defines the upper wall of the combustion chamber and the lower wall of the water tank and this causes the firing plate to become overheated at localised regions and the firing plate burns out and has to be replaced which is an expensive operation. According to the present invention there is provided a vertical tube boiler comprising a plurality of vertical tubes which extend from a combustion chamber, through a water tank to an upper chamber provided with a flue outlet, a secondary plate being provided in the tank above and vertically spaced from a firing plate which forms the bottom wall of the tank and the upper wall of the combustion chamber, said tubes extending through holes provided in said secondary plate with a gap being formed between the outside surfaces of the tubes and the periphery of the holes in said secondary plate, means for supplying water into the space formed between the secondary plate and the firing plate, said water being caused to flow upwardly through said gaps. The upward flow of water through said gaps creates an upward current to cause any scale removed from the tubes to be held in suspension in the water. If any removed scale does descend to the bottom of the tank then it collects on the secondary plate and not on the firing plate. An embodiment of the invention will now be described, by way of an example, with reference to the accompanying drawing, in which: Figure 1 is a longitudinai section through a vertical tube boiler according to the present invention, Figure 2 is a plan view of the boiler, Figure 3 is a cross-section through the boiler taken along the line 3-3 indicated in Fig. 1, and Figure 4 is a cross-section taken along the line 4-4 indicated in Fig. 1. The vertical tube boiler comprises water tank 10 having an upper wail 11 and a bottom wall 1 2 usually referred to as the firing plate. Located above the upper wall 11 is an upper chamber 1 3 provided with a flue outlet 14. Located beneath the firing plate 1 2 is a combustion chamber 1 5. The combustion chamber 1 5 is provided with fuel burners 1 6. Extending between the chambers 1 3 and 1 5 are a plurality of vertical tubes 1 7 through which the hot combustion gases flow. Each tube 1 7 may contain turbulator means which cause the gases to scrub against the inner surface of the tube 1 7. The tank 10 is surrounded by heat insulating means 1 8. Located within the tank 10 is a secondary transverse plate 1 9 provided with a plurality of holes 20 through which the tubes 1 7 extend with a clearance gap between the periphery of each hole 20 and the outside of the associated tube 1 7. An inlet conduit 21 is connected to the tank 10 in the region between the plate 1 9 and the plate 1 2. An outlet conduit 22 is connected to the upper end region of the tank 10. A circulating pump 23 is provided in the flow circuit between the conduits 21 and 22. The pump 23 may be an existing circulating pump or a secondary pump. The gap between the peripheries of the holes 20 and the tubes 1 7 may be approximately 5 millimetres. In use of the boiler the water which flows through the inlet conduit 21 creates an upward flow through the gaps surrounding the tubes 1 7 and this flow creates upward currents which hold any scale removed from the outside of the tubes 1 7 in suspension in the water. If any scale drops to the bottom of the tank 10 then it accumulates on the secondary plate 1 9 and does not contact the firing plate 12. With such an arrangement there is little or no temperature stratification within the water contained in the tank 10 and therefore a temperature sensing control device 24 can be located at any desired position. An over temperature control 25 is provided at the upper end of the tank 1 0. The pressure within the chamber formed between the plate 1 2 and plate 1 9 is that produced by the head of water plus the circulating pressure produced by the pump 23. Even when the boiler is inoperative the pump 23 continues to operate and thus there is always a flow through the gaps surrounding the tubes 17. CLAIMS

2. A vertical tube boiler as claimed in claim 1, in which each tube contains means for causing gases flowing along the tube to scrub against the inner surface of the tube.

3. A vertical tube boiler as claimed in claim 1 or claim 2, in which the tank is surrounded by heat insulating material.

4. A vertical tube boiler as claimed in any preceding claim, including a pump for circulating water between the means for supplying water and an outlet provided in the upper end region of the tank.

5. A vertical tube boiler substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.