GB2325986A

GB2325986A - Exhaust manifold test rig

Info

Publication number: GB2325986A
Application number: GB9711623A
Authority: GB
Inventors: John F Bowles
Original assignee: SCOTT GIBBIN Ltd
Current assignee: SCOTT GIBBIN Ltd
Priority date: 1997-06-06
Filing date: 1997-06-06
Publication date: 1998-12-09
Also published as: GB9711623D0

Abstract

A piece of equipment comprising a burner unit A capable of delivering hot exhaust gas and cold chilled air in cycles to an exhaust manifold via a cylinder head arrangement in order to test the design and manufactured parameters of exhaust manifolds. The exhaust manifold test rig will conserve fuel by utilising the waste heat from the manifold by pre-heating the incoming primary combustion air in a heat exchanger, E thereby achieving a higher overall efficiency. Other than the temperatures and cycle times, the test rig will be capable of altering other operating conditions such as types of primary fuel burned by appropriate selection of burner and a multi-manifold version can be used to test several manifolds at the same time.

Description

EXHAUST MANIFOLD TEST RIG This invention relates to an exhaust manifold test rig.

Scott Gibbin Ltd. is a specialist engine testing company and develops innovative means to provide test solutions for engines and their components. The long term aim of such testing is to enable manufacturers to build those components and completed engines that will overcome deficiencies highlighted by the testing procedures, thereby increasing the life of such components.

This invention is intended to provide a means for testing the exhaust manifold of all types of internal combustion engine and provide an environment similar to that experienced whilst in normal use but allowing the company the flexibility to vary those conditions to suit the test. Also, extremes in temperature variation are to be achieved but the overall system should be operated economically with the minimum energy input. In this way, accelerated ageing of the component under test can be achieved that will expose faults in the design and manufacture such as cracks in the casting, faults in the manufacturing process, and design imperfections leading to premature failure.

To achieve the differences in temperature, a natural gas burner (A) is to be used capable of being switched on and off at regular intervals. The exhaust gas from the burner will pass through a distribution box (B) attached to which will be a cylinder head of a size suitable for the type of exhaust manifold under test. The exhaust manifold (C) is bolted or clamped onto the cylinder head in the same way as it would be fastened under normal operating conditions.

The exhaust gas thus passes into the manifold under test and heats it in a similar fashion to normal operating conditions. From the manifold the exhaust gas continues its flow into the catalytic converter (D). Although, using natural gas, there is no need for a catalytic converter which converts noxious fumes and unburned hydrocarbons to safer emissions, the use ofthe 'cat' in this instance is to provide the same conditions as would be found under normal engine operation.

To reduce the amount of primary fuel and improve heat up time, the hot exhaust gases then pass through a heat exchanger (E) before being discharged to atmosphere via the company's exhaust systems. The heat from the outgoing gases being passed to the inlet air flow to serve the burner with primary combustion air. In this way, the overall efficiency of the test rig will be increased as less heat from the combustion of the fuel gas will be needed to achieve the desired temperature.

To expose the exhaust manifolds under test to extremes of temperature, the test rig will be designed to provide temperatures at the outlet of the manifold (x) of9500C dropping to 100"C on the cooling cycle although wider capability will be possible should this be required.

To achieve a rapid chilling effect, the air for the cooling cycle will pass through a chiller, the motive force for the passage of air being the primary combustion air fan contained within the burner assembly.

There will be a system of valves to control the route of the air; during the cooling cycle, the chiller will be ON and the air will be drawn through the chiller coils, the burner being OFF. After a preset time, which can be varied according to the test procedure, the burner will activate, the air will be diverted through the heat exchanger, the chiller turned off and the manifold under test subjected to the predetermined temperature for the set time. Once again, after this time, the burner will turn off, the valve controlling air flow will divert the air from the heat exchanger through the chiller and the chiller will be turned on. This cycle will be electrically controlled and the profile of cycle times recorded.

The fan will not be turned off during the heating and cooling cycles - the conditions will be varied by the use of the diverter valves and the ON/OFF operation of the burner and the chiller only.

Claims

1. An exhaust manifold test rig capable of exposing exhaust manifolds to extremes of temperature under controlled conditions whilst at the same time conserving fuel by the use of a heat exchanger to pre-heat primary combustion air.

2. An exhaust manifold test rig as claimed in Claim 1 incorporating a chiller to reduce the temperature of inlet air thereby reducing cycle times and achieving lower temperatures during the cooling cycle.

3. An exhaust manifold test rig as claimed in Claims 1 and 2 above incorporating several multi-port cylinder heads to enable a number of exhaust manifolds of various designs and/or materials of construction to be tested at the same time.

This will allow virtually identical conditions to prevail whilst testing different designs of manifold.

4. An exhaust manifold test rig as claimed in Claims 1, 2 and 3 using an alternative fuel source other than natural gas e.g. propane, butane, fuel oil or other suitable fuel.

5. An exhaust manifold test rig as claimed in all preceding claims where the primary air supply is modified by altering its normal composition e.g. by enrichment with oxygen to achieve stoichiometric combustion at various air flow rates and achieve different conditions in the manifold under test.

6. An exhaust manifold test rig as claimed in all preceding claims where materials or substances may be introduced into the gas streams either before or after the burner to cause deposition of carbon or other contaminants into the manifold under test in order to assess the effects of such contaminants.